1
|
Hunt E, Hogan A, Will EA, Roberts JE. ADHD and ASD symptoms in young males with fragile X syndrome: associations with early trajectories of inhibitory control. Child Neuropsychol 2023; 29:760-786. [PMID: 36082630 PMCID: PMC9995619 DOI: 10.1080/09297049.2022.2120605] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/29/2022] [Indexed: 10/14/2022]
Abstract
Inhibitory control (IC), the ability to suppress inappropriate responses, emerges late in the first year of life and improves across typical development, concurrent with brain maturation. The development of IC is critical to various social-emotional and behavioral functions, with IC difficulties being linked to numerous neurodevelopmental disorders, including attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Fragile X syndrome (FXS) is a single-gene disorder characterized by IC difficulties, and elevated rates of ADHD and ASD, making it a useful model for understanding the early development and consequences of IC. In this longitudinal study, we characterized IC trajectories across multiple time points between 16 and 71 months of age in young males with FXS (n = 79) relative to neurotypical (NT) controls (n=49). To explore the association between behavioral outcomes and IC, we identified a subsample of 50 children with longitudinal IC data and an outcome assessment for ADHD and ASD symptoms at age 5 (FXS: n = 26, NT: n = 24). Results indicated that, compared to their NT peers, young males with FXS exhibit differences in IC as early as 24 months, with group differences increasing through age 5. Additionally, we determined that lower IC levels at 24 months were associated with later ADHD symptoms and a decreasing slope in IC over time was associated with later ASD symptoms in male children with FXS. These findings help refine early developmental phenotypes of FXS and highlight IC as a potential target for early detection and intervention of ASD and ADHD symptoms in male children with FXS.
Collapse
Affiliation(s)
- Erin Hunt
- Department of Psychology, University of South Carolina, Columbia, SC, USA
| | - Abigail Hogan
- Department of Psychology, University of South Carolina, Columbia, SC, USA
| | - Elizabeth A Will
- Department of Psychology, University of South Carolina, Columbia, SC, USA
| | - Jane E Roberts
- Department of Psychology, University of South Carolina, Columbia, SC, USA
| |
Collapse
|
2
|
Crawford H. Social Anxiety in Neurodevelopmental Disorders: The Case of Fragile X Syndrome. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2023; 128:302-318. [PMID: 37470255 DOI: 10.1352/1944-7558-128.4.302] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 10/04/2022] [Indexed: 07/21/2023]
Abstract
Despite significant advances in understanding and treating social anxiety in the general population, progress in this area lags behind for individuals with intellectual disability. Fragile X syndrome is the most common cause of inherited intellectual disability and is associated with an elevated prevalence rate of social anxiety. The phenotype of fragile X syndrome encompasses multiple clinically significant characteristics that are posed as risk markers for social anxiety in other populations. Here, evidence is reviewed that points to physiological hyperarousal, sensory sensitivity, emotion dysregulation, cognitive inflexibility, and intolerance of uncertainty as primary candidates for underlying mechanisms of heightened social anxiety in fragile X syndrome. A multilevel model is presented that provides a framework for future research to test associations.
Collapse
|
3
|
Brandalise F, Kalmbach BE, Cook EP, Brager DH. Impaired dendritic spike generation in the Fragile X prefrontal cortex is due to loss of dendritic sodium channels. J Physiol 2023; 601:831-845. [PMID: 36625320 PMCID: PMC9970745 DOI: 10.1113/jp283311] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Patients with Fragile X syndrome, the leading monogenetic cause of autism, suffer from impairments related to the prefrontal cortex, including working memory and attention. Synaptic inputs to the distal dendrites of layer 5 pyramidal neurons in the prefrontal cortex have a weak influence on the somatic membrane potential. To overcome this filtering, distal inputs are transformed into local dendritic Na+ spikes, which propagate to the soma and trigger action potential output. Layer 5 extratelencephalic (ET) prefrontal cortex (PFC) neurons project to the brainstem and various thalamic nuclei and are therefore well positioned to integrate task-relevant sensory signals and guide motor actions. We used current clamp and outside-out patch clamp recording to investigate dendritic spike generation in ET neurons from male wild-type and Fmr1 knockout (FX) mice. The threshold for dendritic spikes was more depolarized in FX neurons compared to wild-type. Analysis of voltage responses to simulated in vivo 'noisy' current injections showed that a larger dendritic input stimulus was required to elicit dendritic spikes in FX ET dendrites compared to wild-type. Patch clamp recordings revealed that the dendritic Na+ conductance was significantly smaller in FX ET dendrites. Taken together, our results suggest that the generation of Na+ -dependent dendritic spikes is impaired in ET neurons of the PFC in FX mice. Considering our prior findings that somatic D-type K+ and dendritic hyperpolarization-activated cyclic nucleotide-gated-channel function is reduced in ET neurons, we suggest that dendritic integration by PFC circuits is fundamentally altered in Fragile X syndrome. KEY POINTS: Dendritic spike threshold is depolarized in layer 5 prefrontal cortex neurons in Fmr1 knockout (FX) mice. Simultaneous somatic and dendritic recording with white noise current injections revealed that larger dendritic stimuli were required to elicit dendritic spikes in FX extratelencephalic (ET) neurons. Outside-out patch clamp recording revealed that dendritic sodium conductance density was lower in FX ET neurons.
Collapse
Affiliation(s)
- Federico Brandalise
- Center for Learning and Memory, University of Texas at Austin, Austin, TX 78712 USA
- Department of Neuroscience University of Texas at Austin, Austin, TX 78712 USA
- Current address: Department of Biosciences, University of Milan, Milano Italy
| | - Brian E. Kalmbach
- Center for Learning and Memory, University of Texas at Austin, Austin, TX 78712 USA
- Department of Neuroscience University of Texas at Austin, Austin, TX 78712 USA
- Current address: Allen Institute for Brain Science, Seattle, WA and Department of Physiology and Biophysics, University of Washington
| | - Erik P. Cook
- Department of Physiology, McGill University, Montreal QC, Canada
| | - Darrin H. Brager
- Center for Learning and Memory, University of Texas at Austin, Austin, TX 78712 USA
- Department of Neuroscience University of Texas at Austin, Austin, TX 78712 USA
| |
Collapse
|
4
|
Brkić D, Ng-Cordell E, O'Brien S, Martin J, Scerif G, Astle D, Baker K. [Formula: see text]FarmApp: a new assessment of cognitive control and memory for children and young people with neurodevelopmental difficulties. Child Neuropsychol 2022; 28:1097-1115. [PMID: 35332845 DOI: 10.1080/09297049.2022.2054968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We introduce a new touchscreen-based method measuring aspects of cognitive control and memory, in children and young people with neurodevelopmental difficulties, including intellectual disability (ID). FarmApp is a gamified, tablet-based assessment tool measuring go/no-go response speed, response inhibition, visuospatial short-term memory span, and long-term memory. Here, we assessed the feasibility, validity, and utility of the method, including the benefits of measuring change in performance over two weeks. We observed that: 1) a higher proportion of participants completed FarmApp than traditional psychometric tests; 2) this proportion increased when participants had opportunity for two weeks of self-paced testing at home; 3) ADHD-relevant behavioral difficulties were associated with average go/no-go performance across all attempts, and change in go/no-go performance over time, indicating sensitivity of the method to cognitive differences with real-world relevance. We also addressed the potential utility of the FarmApp for exploring links between ID etiology and cognitive processes. We observed differences in go/no-go task between two groups of ID participants stratified by the physiological functions of associated genetic variants (chromatin-related and synaptic-related). Moreover, the synaptic group demonstrated higher degree of improvement in go/no-go performance over time. This outcome is potentially informative of dynamic mechanisms contributing to cognitive difficulties within this group. In sum, FarmApp is a feasible, valid, and useful tool increasing access to cognitive assessment for individuals with neurodevelopmental difficulties of variable severity, with an added opportunity to monitor variation in performance over time and determine capacity to acquire task competence.
Collapse
Affiliation(s)
- Diandra Brkić
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, United Kingdom
| | - Elise Ng-Cordell
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, United Kingdom.,Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Sinéad O'Brien
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, United Kingdom
| | - Jessica Martin
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, United Kingdom.,Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Gaia Scerif
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Duncan Astle
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, United Kingdom
| | - Kate Baker
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
5
|
Smith AD, De Lillo C. Sources of variation in search and foraging: A theoretical perspective. Q J Exp Psychol (Hove) 2021; 75:197-231. [PMID: 34609229 DOI: 10.1177/17470218211050314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Search-the problem of exploring a space of alternatives to identify target goals-is a fundamental behaviour for many species. Although its foundation lies in foraging, most studies of human search behaviour have been directed towards understanding the attentional mechanisms that underlie the efficient visual exploration of two-dimensional (2D) scenes. With this review, we aim to characterise how search behaviour can be explained across a wide range of contexts, environments, spatial scales, and populations, both typical and atypical. We first consider the generality of search processes across psychological domains. We then review studies of interspecies differences in search. Finally, we explore in detail the individual and contextual variables that affect visual search and related behaviours in established experimental psychology paradigms. Despite the heterogeneity of the findings discussed, we identify that variations in control processes, along with the ability to regulate behaviour as a function of the structure of search space and the sampling processes adopted, to be central to explanations of variations in search behaviour. We propose a tentative theoretical model aimed at integrating these notions and close by exploring questions that remain unaddressed.
Collapse
Affiliation(s)
| | - Carlo De Lillo
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| |
Collapse
|
6
|
Bush L, Scott MN. Neuropsychological and ASD phenotypes in rare genetic syndromes: A critical review of the literature. Clin Neuropsychol 2021; 36:993-1027. [PMID: 34569897 DOI: 10.1080/13854046.2021.1980111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVE Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by core deficits in social communication and restricted and repetitive behaviors and interests. Recent advances in clinical genetics have improved our understanding of genetic syndromes associated with ASD, which has helped clarify distinct etiologies of ASD and document syndrome-specific profiles of neurocognitive strengths and weaknesses. Pediatric neuropsychologists have the potential to be impactful members of the care team for children with genetic syndromes and their families. METHOD We provide a critical review of the current literature related to the neuropsychological profiles of children with four genetic syndromes associated with ASD, including Tuberous Sclerosis Complex (TSC), fragile X syndrome (FXS), 22q11.2 deletion syndrome, and Angelman syndrome. Recommendations for assessment, intervention, and future directions are provided. RESULTS There is vast heterogeneity in terms of the cognitive, language, and developmental abilities of these populations. The within- and across-syndrome variability characteristic of genetic syndromes should be carefully considered during clinical evaluations, including possible measurement limitations, presence of intellectual disability, and important qualitative differences in the ASD-phenotypes across groups. CONCLUSIONS Individuals with genetic disorders pose challenging diagnostic and assessment questions. Pediatric neuropsychologists with expertise in neurodevelopmental processes are well suited to address these questions and identify profiles of neurocognitive strengths and weaknesses, tailor individualized recommendations, and provide diagnostic clarification.
Collapse
Affiliation(s)
- Lauren Bush
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Megan N Scott
- The Pritzker Department of Psychiatry and Behavioral Health, Ann & Robert H. Lurie Children's Hospital of Chicago, IL, USA
| |
Collapse
|
7
|
Harrop C, Dallman AR, Lecavalier L, Bodfish JW, Boyd BA. Behavioral Inflexibility Across Two Neurogenetic Conditions: Down Syndrome and Fragile X Syndrome. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2021; 126:409-420. [PMID: 34428269 DOI: 10.1352/1944-7558-126.5.409] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 01/12/2021] [Indexed: 06/13/2023]
Abstract
Behavioral inflexibility (BI) has been highlighted to occur across genetic and neurodevelopmental disorders. This study characterized BI in two common neurogenetic conditions: Fragile X syndrome (FXS) and Down syndrome (DS). Caregivers of children with FXS (N = 56; with ASD = 28; FXS only = 28) and DS (N = 146) completed the Behavioral Inflexibility Scale (BIS) via an online survey. Total BIS scores were higher in FXS+ASD than both FXS only and DS (p <.001). Most endorsed items were similar across the three groups, but scores were higher in the FXS+ASD group. In all groups, BI associated with other clinical variables (receptive behaviors, anxiety, social communication). The current data suggest that BI is variable across neurogenetic conditions and higher in individuals with comorbid ASD.
Collapse
Affiliation(s)
- Clare Harrop
- Clare Harrop*, University of North Carolina at Chapel Hill
| | | | | | | | - Brian A Boyd
- Brian A. Boyd, Juniper Gardens Children's Project, Kansas University
| |
Collapse
|
8
|
Zagaria T, Antonucci G, Buono S, Recupero M, Zoccolotti P. Executive Functions and Attention Processes in Adolescents and Young Adults with Intellectual Disability. Brain Sci 2021; 11:brainsci11010042. [PMID: 33401550 PMCID: PMC7823832 DOI: 10.3390/brainsci11010042] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/22/2020] [Accepted: 12/31/2020] [Indexed: 11/16/2022] Open
Abstract
(1) Background: We made a comprehensive evaluation of executive functions (EFs) and attention processes in a group of adolescents and young adults with mild intellectual disability (ID). (2) Methods: 27 adolescents and young adults (14 females and 13 males) with ID, aged between 15.1 and 23 years (M = 17.4; SD = 2.04), were compared to a control group free of cognitive problems and individually matched for gender and age. (3) Results: As for EFs, individuals with ID were severely impaired on all subtests of the Behavioral Assessment of Dysexecutive Syndrome (BADS) battery. However, we also found appreciable individual differences, with eight individuals (approximately 30%) scoring within normal limits. On the attention tests, individuals with ID were not generally slower but presented specific deficits only on some attention tests (i.e., Choice Reaction Times, Color Naming and Color–Word Interference, and Shifting of Attention for Verbal and for Visual Targets).The role of a global factor (i.e., cognitive speed) was modest in contributing to the group differences; i.e., when present, group differences were selectively associated with specific task manipulations, not global differences in cognitive speed. (4) Conclusions: The study confirmed large group differences in EFs; deficits in attentional processing were more specific and occurred primarily in tasks taxing the selective dimension of attention, with performance on intensive tasks almost entirely spared.
Collapse
Affiliation(s)
- Tommasa Zagaria
- Oasi Research Institute-IRCCS, 94018 Troina, Italy; (S.B.); (M.R.)
- Correspondence:
| | - Gabriella Antonucci
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (G.A.); (P.Z.)
- IRCCS Santa Lucia Foundation, 00179 Rome, Italy
| | - Serafino Buono
- Oasi Research Institute-IRCCS, 94018 Troina, Italy; (S.B.); (M.R.)
| | | | - Pierluigi Zoccolotti
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy; (G.A.); (P.Z.)
- IRCCS Santa Lucia Foundation, 00179 Rome, Italy
| |
Collapse
|
9
|
Guy J, Ng-Cordell E, Doherty BR, Duta M, Scerif G. Understanding attention, memory and social biases in fragile X syndrome: Going below the surface with a multi-method approach. RESEARCH IN DEVELOPMENTAL DISABILITIES 2020; 104:103693. [PMID: 32505967 DOI: 10.1016/j.ridd.2020.103693] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 05/08/2020] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
Fragile X syndrome (FXS) is characterised by atypical social behaviours, such as gaze aversion. However, it remains unclear whether, or if so how, these behaviours affect cognitive processing and influence memory. We asked children with FXS (N = 16) and typically developing children (TD; N = 46) to explore naturalistic scenes containing social and non-social salient items unrelated to their task at hand (searching for a simple target object). We also assessed children's memory for target locations. We complemented behavioural responses with eye-tracking data for the subset of participants who managed to comply with calibration and the demands of the experimental testing session (6 children with FXS and 43 TD children). Children with FXS performed well at the experimental task, and showed similar accuracy and speed in locating targets in natural scenes to children of equivalent verbal abilities. They also learned target locations over blocks, but their memory of target locations was not as precise as that of comparison children. In addition, children with FXS initially directed few first looks to salient social items within the scenes, but these looks increased over blocks. Like TD children, children with FXS also dwelled gaze upon social items while recalling target locations from memory. Individual differences in everyday social characteristics also related to gaze and behavioural measures. In conclusion, experimental approaches can highlight cognitive underpinnings of atypical social behaviour in FXS, pinpointing both similarities and differences to TD individuals.
Collapse
Affiliation(s)
- Jacalyn Guy
- Department of Experimental Psychology, University of Oxford, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, United Kingdom
| | - Elise Ng-Cordell
- Department of Experimental Psychology, University of Oxford, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, United Kingdom
| | - Brianna Ruth Doherty
- Department of Experimental Psychology, University of Oxford, United Kingdom; Medical School, University of California at San Francisco, United States
| | - Mihaela Duta
- Department of Experimental Psychology, University of Oxford, United Kingdom
| | - Gaia Scerif
- Department of Experimental Psychology, University of Oxford, United Kingdom.
| |
Collapse
|
10
|
Kramvis I, van Westen R, Lammertse HCA, Riga D, Heistek TS, Loebel A, Spijker S, Mansvelder HD, Meredith RM. Dysregulated Prefrontal Cortex Inhibition in Prepubescent and Adolescent Fragile X Mouse Model. Front Mol Neurosci 2020; 13:88. [PMID: 32528248 PMCID: PMC7264168 DOI: 10.3389/fnmol.2020.00088] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/28/2020] [Indexed: 11/13/2022] Open
Abstract
Changes in excitation and inhibition are associated with the pathobiology of neurodevelopmental disorders of intellectual disability and autism and are widely described in Fragile X syndrome (FXS). In the prefrontal cortex (PFC), essential for cognitive processing, excitatory connectivity and plasticity are found altered in the FXS mouse model, however, little is known about the state of inhibition. To that end, we investigated GABAergic signaling in the Fragile X Mental Retardation 1 (FMR1) knock out (Fmr1-KO) mouse medial PFC (mPFC). We report changes at the molecular, and functional levels of inhibition at three (prepubescence) and six (adolescence) postnatal weeks. Functional changes were most prominent during early postnatal development, resulting in stronger inhibition, through increased synaptic inhibitory drive and amplitude, and reduction of inhibitory short-term synaptic depression. Noise analysis of prepubescent post-synaptic currents demonstrated an increased number of receptors opening during peak current in Fmr1-KO inhibitory synapses. During adolescence amplitudes and plasticity changes normalized, however, the inhibitory drive was now reduced in Fmr1-KO, while synaptic kinetics were prolonged. Finally, adolescent GABAA receptor subunit α2 and GABAB receptor subtype B1 expression levels were different in Fmr1-KOs than WT littermate controls. Together these results extend the degree of synaptic GABAergic alterations in FXS, now to the mPFC of Fmr1-KO mice, a behaviourally relevant brain region in neurodevelopmental disorder pathology.
Collapse
Affiliation(s)
- Ioannis Kramvis
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, Netherlands
| | - Rhodé van Westen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, Netherlands
| | - Hanna C A Lammertse
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, Netherlands
| | - Danai Riga
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, Netherlands
| | - Tim S Heistek
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, Netherlands
| | - Alex Loebel
- Department of Neurobiology, Ludwig-Maximilians Universitat, Munich, Germany
| | - Sabine Spijker
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, Netherlands
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, Netherlands
| | - Rhiannon M Meredith
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, Netherlands
| |
Collapse
|
11
|
Shields RH, Kaat AJ, McKenzie FJ, Drayton A, Sansone SM, Coleman J, Michalak C, Riley K, Berry-Kravis E, Gershon RC, Widaman KF, Hessl D. Validation of the NIH Toolbox Cognitive Battery in intellectual disability. Neurology 2020; 94:e1229-e1240. [PMID: 32094241 PMCID: PMC7274932 DOI: 10.1212/wnl.0000000000009131] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/31/2019] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To advance the science of cognitive outcome measurement for individuals with intellectual disability (ID), we established administration guidelines and evaluated the psychometric properties of the NIH-Toolbox Cognitive Battery (NIHTB-CB) for use in clinical research. METHODS We assessed feasibility, test-retest reliability, and convergent validity of the NIHTB-CB (measuring executive function, processing speed, memory, and language) by assessing 242 individuals with fragile X syndrome (FXS), Down syndrome (DS), and other ID, ages 6 through 25 years, with retesting completed after 1 month. To facilitate accessibility and measurement accuracy, we developed accommodations and standard assessment guidelines, documented in an e-manual. Finally, we assessed the sensitivity of the battery to expected syndrome-specific cognitive phenotypes. RESULTS Above a mental age of 5.0 years, all tests had excellent feasibility. More varied feasibility across tests was seen between mental ages of 3 and 4 years. Reliability and convergent validity ranged from moderate to strong. Each test and the Crystallized and Fluid Composite scores correlated moderately to strongly with IQ, and the Crystallized Composite had modest correlations with adaptive behavior. The NIHTB-CB showed known-groups validity by detecting expected executive function deficits in FXS and a receptive language deficit in DS. CONCLUSION The NIHTB-CB is a reliable and valid test battery for children and young adults with ID with a mental age of ≈5 years and above. Adaptations for very low-functioning or younger children with ID are needed for some subtests to expand the developmental range of the battery. Studies examining sensitivity to developmental and treatment changes are now warranted.
Collapse
Affiliation(s)
- Rebecca H Shields
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Aaron J Kaat
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Forrest J McKenzie
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Andrea Drayton
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Stephanie M Sansone
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Jeanine Coleman
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Claire Michalak
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Karen Riley
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Elizabeth Berry-Kravis
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Richard C Gershon
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - Keith F Widaman
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside
| | - David Hessl
- From the University of California Davis Medical Center (R.H.S.); Human Development Graduate Group (R.H.S.), University of California Davis, Sacramento; Feinberg School of Medicine (A.J.K., R.C.G.), Northwestern University, Chicago, IL; MIND Institute and Department of Psychiatry and Behavioral Sciences (F.J.M., A.D., S.M.S., D.H.), University of California Davis Medical Center, Sacramento; Morgridge College of Education (J.C., K.R.), University of Denver, CO; Departments of Pediatrics (C.M., E.B.-K.) Neurological Sciences (E.B.-K.), and Biochemistry (E.B.-K.), Rush University Medical Center, Chicago, IL; and Graduate School of Education (K.F.W.), University of California, Riverside.
| |
Collapse
|
12
|
Nayar K, McKinney W, Hogan AL, Martin GE, La Valle C, Sharp K, Berry-Kravis E, Norton ES, Gordon PC, Losh M. Language processing skills linked to FMR1 variation: A study of gaze-language coordination during rapid automatized naming among women with the FMR1 premutation. PLoS One 2019; 14:e0219924. [PMID: 31348790 PMCID: PMC6660192 DOI: 10.1371/journal.pone.0219924] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 07/03/2019] [Indexed: 01/15/2023] Open
Abstract
The FMR1 premutation (PM) is relatively common in the general population. Evidence suggests that PM carriers may exhibit subtle differences in specific cognitive and language abilities. This study examined potential mechanisms underlying such differences through the study of gaze and language coordination during a language processing task (rapid automatized naming; RAN) among female carriers of the FMR1 PM. RAN taps a complex set of underlying neuropsychological mechanisms, with breakdowns implicating processing disruptions in fundamental skills that support higher order language and executive functions, making RAN (and analysis of gaze/language coordination during RAN) a potentially powerful paradigm for revealing the phenotypic expression of the FMR1 PM. Forty-eight PM carriers and 56 controls completed RAN on an eye tracker, where they serially named arrays of numbers, letters, colors, and objects. Findings revealed a pattern of inefficient language processing in the PM group, including a greater number of eye fixations (namely, visual regressions) and reduced eye-voice span (i.e., the eyes' lead over the voice) relative to controls. Differences were driven by performance in the latter half of the RAN arrays, when working memory and processing load are the greatest, implicating executive skills. RAN deficits were associated with broader social-communicative difficulties among PM carriers, and with FMR1-related molecular genetic variation (higher CGG repeat length, lower activation ratio, and increased levels of the fragile X mental retardation protein; FMRP). Findings contribute to an understanding of the neurocognitive profile of PM carriers and indicate specific gene-behavior associations that implicate the role of the FMR1 gene in language-related processes.
Collapse
Affiliation(s)
- Kritika Nayar
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, United States of America
| | - Walker McKinney
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, United States of America
- Clinical Child Psychology Program, University of Kansas, Lawrence, Kansas, United States of America
| | - Abigail L. Hogan
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, United States of America
- Psychology, University of South Carolina, Columbia, South Carolina, United States of America
| | - Gary E. Martin
- St. John’s University, Communication Sciences and Disorders, Queens, New York, United States of America
| | - Chelsea La Valle
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, United States of America
- Psychology, Boston University, Boston, Massachusetts, United States of America
| | - Kevin Sharp
- Pediatrics, Rush University Medical Center, Chicago, Illinois, United States of America
| | | | - Elizabeth S. Norton
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, United States of America
| | - Peter C. Gordon
- Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Molly Losh
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, United States of America
| |
Collapse
|
13
|
Chernenok M, Burris JL, Owen E, Rivera SM. Impaired Attention Orienting in Young Children With Fragile X Syndrome. Front Psychol 2019; 10:1567. [PMID: 31354578 PMCID: PMC6635477 DOI: 10.3389/fpsyg.2019.01567] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 06/20/2019] [Indexed: 11/18/2022] Open
Abstract
Fragile X syndrome (FXS) is a genetic disorder caused by a trinucleotide CGG expansion within the FMR1 gene located on the X chromosome. Children with FXS have been shown to be impaired in dynamic visual attention processing. A key component of dynamic processing is orienting—a perceptual ability that requires disengagement and engagement of attention from one stimulus to fixate on a second. Orienting, specifically the disengagement and engagement of attention, has previously not been studied in young children with FXS. Using an eye tracking gap-overlap task, the present study investigated visual disengagement and engagement in young children with FXS, compared to mental age (MA)- and chronological age (CA)-matched typically developing children. On gap trials, the central stimulus elicited fixation, but then disappeared before the peripheral target appeared, imposing a visual gap between stimuli. On overlap trials, the central stimulus elicited fixation, and remained present when the peripheral target appeared, creating visual competition. A gap effect emerges when latencies to shift to the peripheral target are longer in overlap versus gap conditions, reflecting the recruitment of cortical and subcortical disengagement and engagement mechanisms. The gap effect was measured as the latency to orient attention to the peripheral target during gap versus overlap conditions. Both MA and CA groups showed the expected gap effect, where children were slower to orient to peripheral targets on overlap trials than on gap trials. In contrast, in the FXS group, saccadic latencies between gap and overlap trials were not significantly different, indicating no significant gap effect. These findings suggest disrupted attentional engagement patterns in FXS that may be underlying impairments in attention orienting, and suggest potential targets for attention training in this population.
Collapse
Affiliation(s)
- Mariya Chernenok
- Department of Human Ecology, University of California, Davis, Davis, CA, United States.,Center for Mind and Brain, University of California, Davis, Davis, CA, United States
| | - Jessica L Burris
- Department of Psychology, Rutgers University, Newark, NJ, United States
| | - Emily Owen
- Department of Psychology, University of California, Davis, Davis, CA, United States
| | - Susan M Rivera
- Center for Mind and Brain, University of California, Davis, Davis, CA, United States.,Department of Psychology, University of California, Davis, Davis, CA, United States.,MIND Institute, University of California Davis Medical Center, Sacramento, CA, United States
| |
Collapse
|
14
|
Hessl D, Schweitzer JB, Nguyen DV, McLennan YA, Johnston C, Shickman R, Chen Y. Cognitive training for children and adolescents with fragile X syndrome: a randomized controlled trial of Cogmed. J Neurodev Disord 2019; 11:4. [PMID: 30982467 PMCID: PMC6463634 DOI: 10.1186/s11689-019-9264-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/20/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Individuals with fragile X syndrome (FXS) typically demonstrate profound executive function (EF) deficits that interfere with learning, socialization, and emotion regulation. We completed the first large, non-pharmacological controlled trial for FXS, designed to evaluate the efficacy of Cogmed, a computer/tablet-based working memory (WM) training program. METHODS The study was a randomized, blinded, parallel two-arm controlled trial in 100 children and adolescents with FXS (63 male, 37 female; 15.28 ± 3.36 yrs.). Participants were randomized equally to adaptive (difficulty level adjusted to performance) or non-adaptive (control) Cogmed training. Participants were assessed at home using objective measures of WM (primary outcome) and EF at baseline, following 20-25 caregiver-supported sessions over 5-6 weeks, and at follow-up 3 months after cessation of training. Parents and teachers provided ratings of WM, attention, and EF. RESULTS The WM composite and selective domains of EF (distractibility, cognitive flexibility), as well as parent- and teacher-reported attention and EF, significantly improved across the full study sample, with many changes maintained at follow-up. However, comparisons of improvement between adaptive and non-adaptive control conditions did not differ, showing that progressively challenging the WM system by expanding span length did not provide added benefit overall. CONCLUSIONS Further experimental comparisons are needed before Cogmed working memory training can be considered empirically validated for children with FXS, forming the basis of treatment recommendation. However, given that prior studies show no significant changes on these measures in FXS without treatment, that improvements were maintained for 3 months, and that blinded teachers reported improvements in the classroom, the modest benefits seen in both adaptive and non-adaptive groups overall are unlikely to be attributable to placebo or practice effects alone. Future analyses examining inter-individual differences (e.g., baseline capacity, training efficiency, co-morbidity, training environment, characteristics of training aide) may help to link this intervention to outcomes and potential transfer effects. TRIAL REGISTRATION US National Institutes of Health (ClinicalTrials.gov), NCT02747394 .
Collapse
Affiliation(s)
- David Hessl
- MIND Institute, University of California Davis Medical Center, 2825 50th St, Sacramento, CA 95817 USA
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, 2230 Stockton Blvd, Sacramento, CA 95817 USA
- Translational Psychophysiology and Assessment Laboratory (T-PAL), MIND Institute, UC Davis Medical Center, 2825 50th Street, Sacramento, CA 95817 USA
| | - Julie B. Schweitzer
- MIND Institute, University of California Davis Medical Center, 2825 50th St, Sacramento, CA 95817 USA
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, 2230 Stockton Blvd, Sacramento, CA 95817 USA
| | - Danh V. Nguyen
- Department of Medicine, University of California Irvine, 333 City Blvd. West, Orange, CA 92868 USA
| | - Yingratana A. McLennan
- MIND Institute, University of California Davis Medical Center, 2825 50th St, Sacramento, CA 95817 USA
- Department of Pediatrics, University of California Davis School of Medicine, 2516 Stockton Blvd, Sacramento, CA 95817 USA
| | - Cindy Johnston
- MIND Institute, University of California Davis Medical Center, 2825 50th St, Sacramento, CA 95817 USA
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, 2230 Stockton Blvd, Sacramento, CA 95817 USA
| | - Ryan Shickman
- MIND Institute, University of California Davis Medical Center, 2825 50th St, Sacramento, CA 95817 USA
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, 2230 Stockton Blvd, Sacramento, CA 95817 USA
| | - Yanjun Chen
- Institute for Clinical and Translational Science, Irvine, CA 92697 USA
| |
Collapse
|
15
|
Hessl D, Harvey D, Sansone S, Crestodina C, Chin J, Joshi R, Hagerman RJ, Berry‐Kravis E. Effects of mavoglurant on visual attention and pupil reactivity while viewing photographs of faces in Fragile X Syndrome. PLoS One 2019; 14:e0209984. [PMID: 30653533 PMCID: PMC6336311 DOI: 10.1371/journal.pone.0209984] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 12/14/2018] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Numerous preclinical studies have supported the theory that enhanced activation of mGluR5 signaling, due to the absence or reduction of the FMR1 protein, contributes to cognitive and behavioral deficits in patients with fragile X syndrome (FXS). However multiple phase 2 controlled trials in patients with FXS have failed to demonstrate efficacy of compounds that negatively modulate mGluR5, including two phase 2b randomized controlled trials (RCT) of mavoglurant (AFQ056, Novartis Pharma AG), when the primary measures of interest were behavioral ratings. This has cast some doubt onto the translation of the mGluR5 theory from animal models to humans with the disorder. METHODS We evaluated social gaze behavior-a key phenotypic feature of the disorder-and sympathetic nervous system influence on pupil size using a previously-validated eye tracking paradigm as a biobehavioral probe, in 57 adolescent or adult patients with FXS at baseline and following three months of blinded treatment with one of three doses of mavoglurant or placebo, within the context of the AFQ056 RCTs. RESULTS Patients with FXS treated with mavoglurant demonstrated increased total absolute looking time and number of fixations to the eye region while viewing human faces relative to baseline, and compared to those treated with placebo. In addition, patients had greater pupil reactivity to faces relative to baseline following mavoglurant treatment compared to placebo. DISCUSSION The study shows that negative modulation of mGluR5 activity improves eye gaze behavior and alters sympathetically-driven reactivity to faces in patients with FXS, providing preliminary evidence of this drug's impact on behavior in humans with the disorder.
Collapse
Affiliation(s)
- David Hessl
- MIND Institute, University of California Davis Medical Center, Sacramento, California, United States of America
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, California, United States of America
| | - Danielle Harvey
- Division of Biostatistics, Department of Public Health Sciences, University of California Davis School of Medicine, Davis, CA, United States of America
| | - Stephanie Sansone
- MIND Institute, University of California Davis Medical Center, Sacramento, California, United States of America
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, California, United States of America
| | - Crystal Crestodina
- Department of Pediatrics, Rush University Medical Center, Chicago, IL, United States of America
| | - Jamie Chin
- Department of Pediatrics, Rush University Medical Center, Chicago, IL, United States of America
| | - Reshma Joshi
- Department of Pediatrics, Rush University Medical Center, Chicago, IL, United States of America
| | - Randi J. Hagerman
- MIND Institute, University of California Davis Medical Center, Sacramento, California, United States of America
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, California, United States of America
| | - Elizabeth Berry‐Kravis
- Department of Pediatrics, Rush University Medical Center, Chicago, IL, United States of America
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, United States of America
- Department of Biochemistry, Rush University Medical Center, Chicago, IL, United States of America
| |
Collapse
|
16
|
Schmitt LM, Shaffer RC, Hessl D, Erickson C. Executive Function in Fragile X Syndrome: A Systematic Review. Brain Sci 2019; 9:E15. [PMID: 30654486 PMCID: PMC6356760 DOI: 10.3390/brainsci9010015] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 01/09/2019] [Accepted: 01/11/2019] [Indexed: 12/17/2022] Open
Abstract
Executive function (EF) supports goal-directed behavior and includes key aspects such as working memory, inhibitory control, cognitive flexibility, attention, processing speed, and planning. Fragile X syndrome (FXS) is the leading inherited monogenic cause of intellectual disability and is phenotypically characterized by EF deficits beyond what is expected given general cognitive impairments. Yet, a systematic review of behavioral studies using performance-based measures is needed to provide a summary of EF deficits across domains in males and females with FXS, discuss clinical and biological correlates of these EF deficits, identify critical limitations in available research, and offer suggestions for future studies in this area. Ultimately, this review aims to advance our understanding of the underlying pathophysiological mechanisms contributing to EF in FXS and to inform the development of outcome measures of EF and identification of new treatment targets in FXS.
Collapse
Affiliation(s)
- Lauren M Schmitt
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
| | - Rebecca C Shaffer
- Division of Developmental and Behavioral Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
| | - David Hessl
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, CA 95616, USA.
| | - Craig Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
| |
Collapse
|
17
|
Hooper SR, Hatton D, Sideris J, Sullivan K, Ornstein PA, Bailey DB. Developmental trajectories of executive functions in young males with fragile X syndrome. RESEARCH IN DEVELOPMENTAL DISABILITIES 2018; 81:73-88. [PMID: 29936017 DOI: 10.1016/j.ridd.2018.05.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 05/17/2018] [Accepted: 05/21/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Executive functions (EF) have been identified as impaired in FXS, but few studies have examined their developmental trajectories. AIMS The primary aim of this longitudinal study was to examine the development of EF in young males with FXS compared to Mental Age (MA)-matched controls. METHODS AND PROCEDURES The sample comprised 56 boys with FXS (ages 7-13 years), and 48 MA-matched typical boys (ages 4-8 years). EF tasks included measures of inhibitory control, working memory, cognitive flexibility/set-shifting, problem solving/planning, and processing speed. Tasks were administered at three time points over five-years. OUTCOMES AND RESULTS The MA-Matched Typical boys significantly outperformed the FXS boys on all EF tasks, with the FXS Group showing a pattern of slow, but positive growth on most EF tasks. For working memory tasks, significant interactions were noted between MA and autism symptom severity, and MA and medication status. The probability of task completion increased with higher MA. CONCLUSIONS AND IMPLICATIONS These findings contribute to our understanding of the development of EF in this population. They also lay the foundation for use of EF tasks in treatment efforts, particularly with respect to documenting improvements and practice effects, and in understanding associations with targeted developmental outcomes.
Collapse
Affiliation(s)
- Stephen R Hooper
- Department of Allied Health Sciences, 1028 Bondurant Hall, School of Medicine, University of North Carolina School-Chapel Hill, Chapel Hill, North Carolina, 27599-4120, USA.
| | - Deborah Hatton
- Department of Special Education, Box 228, Peabody College, Vanderbilt University, Nashville, Tennessee, 37203, USA.
| | - John Sideris
- Frank Porter Graham Child Development Institute, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, 27599-4120, USA.
| | - Kelly Sullivan
- Center for Child and Family Health, 1121 West Chapel Hill St., Suite 100, Duke University Medical Center, Durham, NC, 27701, USA.
| | - Peter A Ornstein
- Department of Psychology & Neuroscience, 222 Davie Hall, Campus Box #3270, University of North Carolina-Chapel Hill, Chapel Hill, NC, 27599-3270, USA.
| | | |
Collapse
|
18
|
Robinson M, Klusek J, Poe MD, Hatton DD, Roberts JE. The Emergence of Effortful Control in Young Boys With Fragile X Syndrome. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2018; 123:89-102. [PMID: 29480774 PMCID: PMC6174087 DOI: 10.1352/1944-7558-123.2.89] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Effortful control, or the ability to suppress a dominant response to perform a subdominant response, is an early-emerging temperament trait that is linked with positive social-emotional development. Fragile X syndrome (FXS) is a single-gene disorder characterized by hallmark regulatory impairments, suggesting diminished effortful control. This study compared the development of effortful control in preschool boys with FXS ( n = 97) and typical development ( n = 32). Unlike their typical peers, the boys with FXS did not exhibit growth in effortful control over time, which could not be accounted for by adaptive impairments, FMR1 molecular measures, or autism symptoms. These results contribute to our understanding of the childhood phenotype of FXS that may be linked to the poor social-emotional outcomes seen in this group.
Collapse
Affiliation(s)
- Marissa Robinson
- Marissa Robinson, University of South Carolina, Department of Psychology
| | - Jessica Klusek
- Jessica Klusek, University of South Carolina, Department of Communication Sciences and Disorders
| | - Michele D Poe
- Michele D. Poe, University of Pittsburgh, Program for the Study of Neurodevelopment in Rare Disorders, Pittsburgh
| | - Deborah D Hatton
- Deborah D. Hatton, Vanderbilt University, Department of Special Education; and
| | - Jane E Roberts
- Jane E. Roberts, University of South Carolina, Department of Psychology
| |
Collapse
|
19
|
Intelligence and specific cognitive functions in intellectual disability: implications for assessment and classification. Curr Opin Psychiatry 2018; 31:88-95. [PMID: 29206685 DOI: 10.1097/yco.0000000000000387] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE OF REVIEW Current diagnostic criteria for intellectual disability categorize ability as measured by IQ tests. However, this does not suit the new conceptualization of intellectual disability, which refers to a range of neuropsychiatric syndromes that have in common early onset, cognitive impairments, and consequent deficits in learning and adaptive functioning. A literature review was undertaken on the concept of intelligence and whether it encompasses a range of specific cognitive functions to solve problems, which might be better reported as a profile, instead of an IQ, with implications for diagnosis and classification of intellectual disability. RECENT FINDINGS Data support a model of intelligence consisting of distinct but related processes. Persons with intellectual disability with the same IQ level have different cognitive profiles, based on varying factors involved in aetiopathogenesis. Limitations of functioning and many biopsychological factors associated with intellectual disability are more highly correlated with impairments of specific cognitive functions than with overall IQ. SUMMARY The current model of intelligence, based on IQ, is of limited utility for intellectual disability, given the wide range and variability of cognitive functions and adaptive capacities. Assessing level of individual impairment in executive and specific cognitive functions may be a more useful alternative. This has considerable implications for the revision of the International Classification of Diseases and for the cultural attitude towards intellectual disability in general.
Collapse
|
20
|
Angulo-Chavira AQ, García O, Arias-Trejo N. Pupil response and attention skills in Down syndrome. RESEARCH IN DEVELOPMENTAL DISABILITIES 2017; 70:40-49. [PMID: 28888155 DOI: 10.1016/j.ridd.2017.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 08/23/2017] [Accepted: 08/23/2017] [Indexed: 06/07/2023]
Abstract
Down syndrome (DS) is characterized by attentional problems. Little is known about the neural correlates of attention problems in DS due to difficulties in evaluation. Pupil dilation, associated with an increase in cognitive load and locus coeruleus-noradrenaline system activity in humans, is a neurophysiological measurement that may help to characterize such problems. The aim of this research was to investigate the link between a phasic pupil dilation response and target detection in people with DS, as compared with a control group with typical development (TD) matched by mental age. Participants performed an "oddball" task by means of an eye-tracker and a series of neuropsychological tests. Although the DS and control group demonstrated similar attentional skills and behavioral performance, the participants with DS showed greater pupil dilation. This result suggests that people with DS expend extra cognitive effort to achieve performance similar to those with TD. This finding is discussed in light of the attentional process in DS and the reliability of pupil dilation measurement in the study of attention and other cognitive processes in DS.
Collapse
Affiliation(s)
| | - Octavio García
- Laboratorio de Neurobiología del Síndrome de Down, Facultad de Psicología, Universidad Nacional Autónoma de México, Mexico
| | - Natalia Arias-Trejo
- Laboratorio de Psicolingüística, Facultad de Psicología, Universidad Nacional Autónoma de México, Mexico.
| |
Collapse
|
21
|
Reid D, Moss J, Nelson L, Groves L, Oliver C. Executive functioning in Cornelia de Lange syndrome: domain asynchrony and age-related performance. J Neurodev Disord 2017; 9:29. [PMID: 28806899 PMCID: PMC5556702 DOI: 10.1186/s11689-017-9208-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 06/13/2017] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The aim of this study was to examine executive functioning in adolescents and adults with Cornelia de Lange syndrome (CdLS) to identify a syndrome and age-related profile of cognitive impairment. METHODS Participants were 24 individuals with CdLS aged 13-42 years (M = 22; SD = 8.98), and a comparable contrast group of 21 individuals with Down syndrome (DS) aged 15-33 years (M = 24; SD = 5.82). Measures were selected to test verbal and visual fluency, inhibition, perseverance/flexibility, and working memory and comprised both questionnaire and performance tests. RESULTS Individuals with CdLS showed significantly greater impairment on tasks requiring flexibility and inhibition (rule switch) and on forwards span capacity. These impairments were also reported in the parent/carer-rated questionnaire measures. Backwards Digit Span was significantly negatively correlated with chronological age in CdLS, indicating increased deficits with age. This was not identified in individuals with DS. CONCLUSIONS The relative deficits in executive functioning task performance are important in understanding the behavioural phenotype of CdLS. Prospective longitudinal follow-up is required to examine further the changes in executive functioning with age and if these map onto observed changes in behaviour in CdLS. Links with recent research indicating heightened responses to oxidative stress in CdLS may also be important.
Collapse
Affiliation(s)
- Donna Reid
- Cerebra Centre of Neurodevelopmental Disorders, University of Birmingham, Birmingham, UK
| | - Jo Moss
- Cerebra Centre of Neurodevelopmental Disorders, University of Birmingham, Birmingham, UK.
- Institute of Cognitive Neuroscience, University College London, London, UK.
| | - Lisa Nelson
- Cerebra Centre of Neurodevelopmental Disorders, University of Birmingham, Birmingham, UK
| | - Laura Groves
- Cerebra Centre of Neurodevelopmental Disorders, University of Birmingham, Birmingham, UK
| | - Chris Oliver
- Cerebra Centre of Neurodevelopmental Disorders, University of Birmingham, Birmingham, UK
| |
Collapse
|
22
|
Prefrontal Cortex Dysfunction in Fragile X Mice Depends on the Continued Absence of Fragile X Mental Retardation Protein in the Adult Brain. J Neurosci 2017; 37:7305-7317. [PMID: 28652410 DOI: 10.1523/jneurosci.0571-17.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/09/2017] [Accepted: 06/10/2017] [Indexed: 01/28/2023] Open
Abstract
Fragile X Syndrome (FX) is generally considered a developmental disorder, arising from a mutation that disrupts the transcription of Fragile X Mental Retardation Protein (FMRP). However, FMRP regulates the transcription of other proteins and participates in an unknown number of protein-protein interactions throughout life. In addition to known developmental issues, it is thus likely that some dysfunction is also due to the ongoing absence of FMRP. Dissociating dysfunction due to developmental dysregulation from dysfunction due to the continued absence of FMRP is necessary to understand the different roles of FMRP and to treat patients effectively throughout life. We show here that FX model mice display substantial deficits in a PFC-dependent task. We then use conditional knock-out mice to eliminate FMRP only in the PFC alone of adult mice. We observe an increase in the proportion of nonlearners and a delay in the onset of learning in both FX and conditional knock-out mice. The results suggest that these deficits (1) are due to the absence of FMRP in the PFC alone and (2) are not the result of developmental dysregulation. Furthermore, PFC-associated deficits are rescued by initiating production of FMRP in adult conditional restoration mice, suggesting that PFC dysfunction may persist as long as FMRP is absent and therefore can be rescued after development. The data suggest that it is possible to dissociate the roles of FMRP in neural function from developmental dysregulation, and that PFC function can be restored in the adult FX brain.SIGNIFICANCE STATEMENT The absence of Fragile X Mental Retardation Protein (FMRP) from birth results in developmental disabilities and lifelong impairments. We show here that in mouse models PFC dysfunction in Fragile X Syndrome (FX) can be attributed to the continued absence of FMRP from the PFC, independent of FMRP status during development. Furthermore, initiation of FMRP production in the PFC of adult FX animals rescues PFC function. The results suggest that at least some FX-specific neurological defects can be rescued in the adult FX brain after development.
Collapse
|
23
|
Budimirovic DB, Berry-Kravis E, Erickson CA, Hall SS, Hessl D, Reiss AL, King MK, Abbeduto L, Kaufmann WE. Updated report on tools to measure outcomes of clinical trials in fragile X syndrome. J Neurodev Disord 2017; 9:14. [PMID: 28616097 PMCID: PMC5467057 DOI: 10.1186/s11689-017-9193-x] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 02/22/2017] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Fragile X syndrome (FXS) has been the neurodevelopmental disorder with the most active translation of preclinical breakthroughs into clinical trials. This process has led to a critical assessment of outcome measures, which resulted in a comprehensive review published in 2013. Nevertheless, the disappointing outcome of several recent phase III drug trials in FXS, and parallel efforts at evaluating behavioral endpoints for trials in autism spectrum disorder (ASD), has emphasized the need for re-assessing outcome measures and revising recommendations for FXS. METHODS After performing an extensive database search (PubMed, Food and Drug Administration (FDA)/National Institutes of Health (NIH)'s www.ClinicalTrials.gov, etc.) to determine progress since 2013, members of the Working Groups who published the 2013 Report evaluated the available outcome measures for FXS and related neurodevelopmental disorders using the COSMIN grading system of levels of evidence. The latter has also been applied to a British survey of endpoints for ASD. In addition, we also generated an informal classification of outcome measures for use in FXS intervention studies as instruments appropriate to detect shorter- or longer-term changes. RESULTS To date, a total of 22 double-blind controlled clinical trials in FXS have been identified through www.ClinicalTrials.gov and an extensive literature search. The vast majority of these FDA/NIH-registered clinical trials has been completed between 2008 and 2015 and has targeted the core excitatory/inhibitory imbalance present in FXS and other neurodevelopmental disorders. Limited data exist on reliability and validity for most tools used to measure cognitive, behavioral, and other problems in FXS in these trials and other studies. Overall, evidence for most tools supports a moderate tool quality grading. Data on sensitivity to treatment, currently under evaluation, could improve ratings for some cognitive and behavioral tools. Some progress has also been made at identifying promising biomarkers, mainly on blood-based and neurophysiological measures. CONCLUSION Despite the tangible progress in implementing clinical trials in FXS, the increasing data on measurement properties of endpoints, and the ongoing process of new tool development, the vast majority of outcome measures are at the moderate quality level with limited information on reliability, validity, and sensitivity to treatment. This situation is not unique to FXS, since reviews of endpoints for ASD have arrived at similar conclusions. These findings, in conjunction with the predominance of parent-based measures particularly in the behavioral domain, indicate that endpoint development in FXS needs to continue with an emphasis on more objective measures (observational, direct testing, biomarkers) that reflect meaningful improvements in quality of life. A major continuous challenge is the development of measurement tools concurrently with testing drug safety and efficacy in clinical trials.
Collapse
Affiliation(s)
- Dejan B. Budimirovic
- Departments of Psychiatry and Behavioral Sciences, Kennedy Krieger Institute and Child Psychiatry, Johns Hopkins University School of Medicine, 716 N. Broadway, Baltimore, MD 21205 USA
| | - Elizabeth Berry-Kravis
- Departments of Pediatrics, Neurological Sciences, Biochemistry, Rush University Medical Center, 1725 West Harrison, Suite 718, Chicago, IL 60612 USA
| | - Craig A. Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center and the University of Cincinnati College of Medicine, 3333 Burnet Avenue MLC 4002, Cincinnati, OH 45229 USA
| | - Scott S. Hall
- Division of Interdisciplinary Brain Sciences, Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305 USA
| | - David Hessl
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, 2825 50th Street, Sacramento, CA 95817 USA
| | - Allan L. Reiss
- Division of Interdisciplinary Brain Sciences, Departments of Psychiatry and Behavioral Sciences, Radiology and Pediatrics, Stanford University, 401 Quarry Road, Stanford, CA 94305 USA
| | - Margaret K. King
- Autism & Developmental Medicine Institute, Geisinger Health System, Present address: Novartis Pharmaceuticals Corporation, US Medical, One Health Plaza, East Hanover, NJ 07936 USA
| | - Leonard Abbeduto
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, 2825 50th Street, Sacramento, CA 95817 USA
| | - Walter E. Kaufmann
- Center for Translational Research, Greenwood Genetic Center, 113 Gregor Mendel Circle, Greenwood, SC 29646 USA
- Department of Neurology, Boston Children’s Hospital, Boston, MA 02115 USA
| |
Collapse
|
24
|
Thurman AJ, Kover ST, Ted Brown W, Harvey DJ, Abbeduto L. Noncomprehension Signaling in Males and Females With Fragile X Syndrome. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2017; 60:1606-1621. [PMID: 28586922 PMCID: PMC5544413 DOI: 10.1044/2016_jslhr-l-15-0358] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 06/10/2016] [Accepted: 12/05/2016] [Indexed: 05/25/2023]
Abstract
Purpose This study used a prospective longitudinal design to evaluate the trajectory and predictors of noncomprehension signaling in male and female youth with fragile X syndrome (FXS). Method A direction-following task in which some of the directions were inadequate was administered. Participants were 52 youth (36 boys, 16 girls) with FXS. Upon study entry, participants ranged from 10 to 16 years. The average number of annual assessments per participant was 3.65 (range = 1-4), providing 198 data points for analysis. Results Participants with FXS were less likely to signal noncomprehension than younger, typically developing, cognitively matched children. The average rate of change in noncomprehension signaling was not significantly different from 0 for either boys or girls, suggesting a plateau. Both FMRP and nonverbal IQ were significant independent predictors of noncomprehension signaling for boys. Variability in noncomprehension signaling among girls was not explained by any of the predictors, but trends similar to those observed for boys were observed. Conclusions Noncomprehension signaling appears to be an area of weakness for individuals with FXS. Because the failure to signal noncomprehension can have negative, cumulative effects on comprehension, the results suggest a need for interventions targeting the requisite cognitive skills.
Collapse
Affiliation(s)
- Angela John Thurman
- MIND Institute, University of California Davis, Sacramento
- Department of Psychiatry and Behavioral Sciences, University of California Davis, Sacramento
| | - Sara T. Kover
- Department of Speech and Hearing Sciences, University of Washington, Seattle
| | - W. Ted Brown
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island
| | | | - Leonard Abbeduto
- MIND Institute, University of California Davis, Sacramento
- Department of Psychiatry and Behavioral Sciences, University of California Davis, Sacramento
| |
Collapse
|
25
|
de la Peña JB, Dela Peña IJ, Custodio RJ, Botanas CJ, Kim HJ, Cheong JH. Exploring the Validity of Proposed Transgenic Animal Models of Attention-Deficit Hyperactivity Disorder (ADHD). Mol Neurobiol 2017; 55:3739-3754. [PMID: 28534274 DOI: 10.1007/s12035-017-0608-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 05/09/2017] [Indexed: 12/31/2022]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common, behavioral, and heterogeneous neurodevelopmental condition characterized by hyperactivity, impulsivity, and inattention. Symptoms of this disorder are managed by treatment with methylphenidate, amphetamine, and/or atomoxetine. The cause of ADHD is unknown, but substantial evidence indicates that this disorder has a significant genetic component. Transgenic animals have become an essential tool in uncovering the genetic factors underlying ADHD. Although they cannot accurately reflect the human condition, they can provide insights into the disorder that cannot be obtained from human studies due to various limitations. An ideal animal model of ADHD must have face (similarity in symptoms), predictive (similarity in response to treatment or medications), and construct (similarity in etiology or underlying pathophysiological mechanism) validity. As the exact etiology of ADHD remains unclear, the construct validity of animal models of ADHD would always be limited. The proposed transgenic animal models of ADHD have substantially increased and diversified over the years. In this paper, we compiled and explored the validity of proposed transgenic animal models of ADHD. Each of the reviewed transgenic animal models has strengths and limitations. Some fulfill most of the validity criteria of an animal model of ADHD and have been extensively used, while there are others that require further validation. Nevertheless, these transgenic animal models of ADHD have provided and will continue to provide valuable insights into the genetic underpinnings of this complex disorder.
Collapse
Affiliation(s)
- June Bryan de la Peña
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Irene Joy Dela Peña
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Raly James Custodio
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Chrislean Jun Botanas
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Hee Jin Kim
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea
| | - Jae Hoon Cheong
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, Republic of Korea.
| |
Collapse
|
26
|
Powers BE, Velazquez R, Kelley CM, Ash JA, Strawderman MS, Alldred MJ, Ginsberg SD, Mufson EJ, Strupp BJ. Attentional function and basal forebrain cholinergic neuron morphology during aging in the Ts65Dn mouse model of Down syndrome. Brain Struct Funct 2016; 221:4337-4352. [PMID: 26719290 PMCID: PMC4929047 DOI: 10.1007/s00429-015-1164-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 11/26/2015] [Indexed: 10/22/2022]
Abstract
Individuals with Down syndrome (DS) exhibit intellectual disability and develop Alzheimer's disease-like neuropathology during the third decade of life. The Ts65Dn mouse model of DS exhibits key features of both disorders, including impairments in learning, attention and memory, as well as atrophy of basal forebrain cholinergic neurons (BFCNs). The present study evaluated attentional function in relation to BFCN morphology in young (3 months) and middle-aged (12 months) Ts65Dn mice and disomic (2N) controls. Ts65Dn mice exhibited attentional dysfunction at both ages, with greater impairment in older trisomics. Density of BFCNs was significantly lower for Ts65Dn mice independent of age, which may contribute to attentional dysfunction since BFCN density was positively associated with performance on an attention task. BFCN volume decreased with age in 2N but not Ts65Dn mice. Paradoxically, BFCN volume was greater in older trisomic mice, suggestive of a compensatory response. In sum, attentional dysfunction occurred in both young and middle-aged Ts65Dn mice, which may in part reflect reduced density and/or phenotypic alterations in BFCNs.
Collapse
Affiliation(s)
- Brian E Powers
- Division of Nutritional Sciences and Department of Psychology, Cornell University, Ithaca, NY, 14853, USA
| | - Ramon Velazquez
- Division of Nutritional Sciences and Department of Psychology, Cornell University, Ithaca, NY, 14853, USA
| | - Christy M Kelley
- Division of Neurological Sciences, Rush University Medical Center, Chicago, IL, 60612, USA
| | - Jessica A Ash
- Division of Nutritional Sciences and Department of Psychology, Cornell University, Ithaca, NY, 14853, USA
| | - Myla S Strawderman
- Division of Nutritional Sciences and Department of Psychology, Cornell University, Ithaca, NY, 14853, USA
| | - Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, 10962, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, 10962, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, 10962, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY, 10962, USA
- Department of Neuroscience and Physiology, New York University Langone Medical Center, New York, NY, 10962, USA
| | - Elliott J Mufson
- Division of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, 85013, USA
| | - Barbara J Strupp
- Division of Nutritional Sciences and Department of Psychology, Cornell University, Ithaca, NY, 14853, USA.
| |
Collapse
|
27
|
Amadó A, Serrat E, Vallès-Majoral E. The Role of Executive Functions in Social Cognition among Children with Down Syndrome: Relationship Patterns. Front Psychol 2016; 7:1363. [PMID: 27679588 PMCID: PMC5020061 DOI: 10.3389/fpsyg.2016.01363] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 08/26/2016] [Indexed: 11/13/2022] Open
Abstract
Many studies show a link between social cognition, a set of cognitive and emotional abilities applied to social situations, and executive functions in typical developing children. Children with Down syndrome (DS) show deficits both in social cognition and in some subcomponents of executive functions. However this link has barely been studied in this population. The aim of this study is to investigate the links between social cognition and executive functions among children with DS. We administered a battery of social cognition and executive function tasks (six theory of mind tasks, a test of emotion comprehension, and three executive function tasks) to a group of 30 participants with DS between 4 and 12 years of age. The same tasks were administered to a chronological-age control group and to a control group with the same linguistic development level. Results showed that apart from deficits in social cognition and executive function abilities, children with DS displayed a slight improvement with increasing chronological age and language development in those abilities. Correlational analysis suggested that working memory was the only component that remained constant in the relation patterns of the three groups of participants, being the relation patterns similar among participants with DS and the language development control group. A multiple linear regression showed that working memory explained above 50% of the variability of social cognition in DS participants and in language development control group, whereas in the chronological-age control group this component only explained 31% of the variability. These findings, and specifically the link between working memory and social cognition, are discussed on the basis of their theoretical and practical implications for children with DS. We discuss the possibility to use a working memory training to improve social cognition in this population.
Collapse
Affiliation(s)
- Anna Amadó
- Department of Psychology, University of Girona Girona, Spain
| | - Elisabet Serrat
- Department of Psychology, University of Girona Girona, Spain
| | - Eduard Vallès-Majoral
- Department of Psychology, University of GironaGirona, Spain; Servei Neuropsicopedagògic ArlotGirona, Spain
| |
Collapse
|
28
|
Hessl D, Sansone SM, Berry-Kravis E, Riley K, Widaman KF, Abbeduto L, Schneider A, Coleman J, Oaklander D, Rhodes KC, Gershon RC. The NIH Toolbox Cognitive Battery for intellectual disabilities: three preliminary studies and future directions. J Neurodev Disord 2016; 8:35. [PMID: 27602170 PMCID: PMC5012003 DOI: 10.1186/s11689-016-9167-4] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/11/2016] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Recent advances in understanding molecular and synaptic mechanisms of intellectual disabilities (ID) in fragile X syndrome (FXS) and Down syndrome (DS) through animal models have led to targeted controlled trials with pharmacological agents designed to normalize these underlying mechanisms and improve clinical outcomes. However, several human clinical trials have failed to demonstrate efficacy of these targeted treatments to improve surrogate behavioral endpoints. Because the ultimate index of disease modification in these disorders is amelioration of ID, the validation of cognitive measures for tracking treatment response is essential. Here, we present preliminary research to validate the National Institutes of Health Toolbox Cognitive Battery (NIH-TCB) for ID. METHODS We completed three pilot studies of patients with FXS (total n = 63; mean age 19.3 ± 8.3 years, mean mental age 5.3 ± 1.6 years), DS (n = 47; mean age 16.1 ± 6.2, mean mental age 5.4 ± 2.0), and idiopathic ID (IID; n = 16; mean age 16.1 ± 5.0, mean mental age 6.6 ± 2.3) measuring processing speed, executive function, episodic memory, word/letter reading, receptive vocabulary, and working memory using the web-based NIH-TB-CB, addressing feasibility, test-retest reliability, construct validity, ecological validity, and syndrome differences and profiles. RESULTS Feasibility was good to excellent (≥80 % of participants with valid scores) for above mental age 4 years for all tests except list sorting (working memory). Test-retest stability was good to excellent, and convergent validity was similar to or better than results obtained from typically developing children in the normal sample for executive function and language measures. Examination of ecological validity revealed moderate to very strong correlations between the NIH-TCB composite and adaptive behavior and full-scale IQ measures. Syndrome/group comparisons demonstrated significant deficits for the FXS and DS groups relative to IID on attention and inhibitory control, a significant reading weakness for FXS, and a receptive vocabulary weakness for DS. CONCLUSIONS The NIH-TCB has potential for assessing important dimensions of cognition in persons with ID, and several tests may be useful for tracking response to intervention. However, more extensive psychometric studies, evaluation of the NIH-TCB's sensitivity to change, both developmentally and in the context of treatment, and perhaps establishing links to brain function in these populations, are required to determine the true utility of the battery as a set of outcome measures.
Collapse
Affiliation(s)
- David Hessl
- Translational Psychophysiology and Assessment Laboratory (T-PAL), MIND Institute, UC Davis Medical Center, Sacramento, CA USA
- Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, Sacramento, CA USA
| | - Stephanie M. Sansone
- Translational Psychophysiology and Assessment Laboratory (T-PAL), MIND Institute, UC Davis Medical Center, Sacramento, CA USA
- Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, Sacramento, CA USA
| | - Elizabeth Berry-Kravis
- Department of Pediatrics, Rush University Medical Center, Chicago, IL USA
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL USA
- Department of Biochemistry, Rush University Medical Center, Chicago, IL USA
| | - Karen Riley
- Morgridge College of Education, The University of Denver, Denver, CO USA
| | - Keith F. Widaman
- Graduate School of Education, University of California Riverside, Riverside, CA USA
| | - Leonard Abbeduto
- Translational Psychophysiology and Assessment Laboratory (T-PAL), MIND Institute, UC Davis Medical Center, Sacramento, CA USA
- Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, Sacramento, CA USA
| | - Andrea Schneider
- Translational Psychophysiology and Assessment Laboratory (T-PAL), MIND Institute, UC Davis Medical Center, Sacramento, CA USA
- Department of Pediatrics, University of California Davis Medical Center, Sacramento, CA USA
| | - Jeanine Coleman
- Morgridge College of Education, The University of Denver, Denver, CO USA
| | - Dena Oaklander
- School of Medicine, Rush University Medical Center, Chicago, IL USA
| | - Kelly C. Rhodes
- School of Medicine, Rush University Medical Center, Chicago, IL USA
| | | |
Collapse
|
29
|
Faught GG, Conners FA, Himmelberger ZM. Auditory and visual sustained attention in Down syndrome. RESEARCH IN DEVELOPMENTAL DISABILITIES 2016; 53-54:135-146. [PMID: 26900779 DOI: 10.1016/j.ridd.2016.01.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 12/17/2015] [Accepted: 01/31/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND Sustained attention (SA) is important to task performance and development of higher functions. It emerges as a separable component of attention during preschool and shows incremental improvements during this stage of development. AIMS The current study investigated if auditory and visual SA match developmental level or are particular challenges for youth with DS. Further, we sought to determine if there were modality effects in SA that could predict those seen in short-term memory (STM). METHODS AND PROCEDURES We compared youth with DS to typically developing youth matched for nonverbal mental age and receptive vocabulary. Groups completed auditory and visual sustained attention to response tests (SARTs) and STM tasks. OUTCOMES AND RESULTS Results indicated groups performed similarly on both SARTs, even over varying cognitive ability. Further, within groups participants performed similarly on auditory and visual SARTs, thus SA could not predict modality effects in STM. However, SA did generally predict a significant portion of unique variance in groups' STM. CONCLUSIONS AND IMPLICATIONS Ultimately, results suggested both auditory and visual SA match developmental level in DS. Further, SA generally predicts STM, though SA does not necessarily predict the pattern of poor auditory relative to visual STM characteristic of DS.
Collapse
Affiliation(s)
- Gayle G Faught
- Department of Psychology, University of Alabama, Box 870348, Tuscaloosa, AL 35487-0348, United States.
| | - Frances A Conners
- Department of Psychology, University of Alabama, Box 870348, Tuscaloosa, AL 35487-0348, United States.
| | - Zachary M Himmelberger
- Department of Psychology, University of Alabama, Box 870348, Tuscaloosa, AL 35487-0348, United States.
| |
Collapse
|
30
|
Ballantyne CJ, Núñez M. Developmental trajectories of hierarchical visuo-spatial processing in fragile X syndrome and ASD: Within- and cross-syndrome variability. RESEARCH IN DEVELOPMENTAL DISABILITIES 2016; 51-52:103-115. [PMID: 26809150 DOI: 10.1016/j.ridd.2015.12.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 12/22/2015] [Accepted: 12/26/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND/AIMS Despite the advances in understanding visuo-spatial processing in developmental disorders such as ASD and fragile X syndrome (FXS), less is known about the profile of those with a comorbid diagnosis, or the role of within-disorder disparities between individuals across the ASD spectrum. METHODS AND PROCEDURES Using a developmental trajectory approach, we tested 5 groups of children: Typically developing, FXS, FXS+ASD, ASD individuals who had low-moderate symptoms (HFA) and ASD individuals who had severe symptoms (LFA). Symptoms of ASD were assessed using the Childhood Autism Rating Scale: CARS and hierarchical visuo-spatial processing was assessed using the Navon task. OUTCOMES AND RESULTS Crucially, results differed between HFA and LFA participants. Furthermore, the pattern of results differed between those who had a diagnosis of FXS only and FXS+ASD. Poorer performance within the FXS groups and the group who are low functioning on the ASD spectrum indicated a delayed developmental rate compared to typical controls. CONCLUSIONS AND IMPLICATIONS This study showed that diagnosis and severity of symptoms are indicative of differences in visuo-spatial processing styles. It is important that heterogeneity within FXS and ASD populations are considered in subsequent studies and look beyond diagnostic group differences.
Collapse
Affiliation(s)
- Carrie J Ballantyne
- Division of Psychology, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - María Núñez
- Division of Psychology, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| |
Collapse
|
31
|
Benjamin DP, McDuffie AS, Thurman AJ, Kover ST, Mastergeorge AM, Hagerman RJ, Abbeduto L. Effect of speaker gaze on word learning in fragile X syndrome: a comparison with nonsyndromic autism spectrum disorder. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2015; 58:383-95. [PMID: 25629603 PMCID: PMC4675125 DOI: 10.1044/2015_jslhr-l-14-0136] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 10/28/2014] [Accepted: 12/03/2014] [Indexed: 06/04/2023]
Abstract
PURPOSE This study examined use of a speaker's direction of gaze during word learning by boys with fragile X syndrome (FXS), boys with nonsyndromic autism spectrum disorder (ASD), and typically developing (TD) boys. METHOD A fast-mapping task with follow-in and discrepant labeling conditions was administered. We expected that the use of speaker gaze would lead to participants selecting as the referent of the novel label the object to which they attended in follow-in trials and the object to which the examiner attended in the discrepant labeling trials. Participants were school-aged boys with FXS (n=18) or ASD (n=18) matched on age, intelligence quotient, and nonverbal cognition and younger TD boys (n=18) matched on nonverbal cognition. RESULTS All groups performed above chance in both conditions, although the TD boys performed closest to the expected pattern. Boys with FXS performed better during follow-in than in discrepant label trials, whereas TD boys and boys with ASD did equally well in both trial types. The type of trial administered first influenced subsequent responding. Error patterns also distinguished the groups. CONCLUSION The ability to utilize a speaker's gaze during word learning is not as well developed in boys with FXS or nonsyndromic ASD as in TD boys of the same developmental level.
Collapse
Affiliation(s)
- David P. Benjamin
- MIND Institute, University of California, Davis
- UC Davis School of Medicine
| | - Andrea S. McDuffie
- MIND Institute, University of California, Davis
- UC Davis School of Medicine
| | - Angela J. Thurman
- MIND Institute, University of California, Davis
- UC Davis School of Medicine
| | | | | | - Randi J. Hagerman
- MIND Institute, University of California, Davis
- UC Davis School of Medicine
| | - Leonard Abbeduto
- MIND Institute, University of California, Davis
- UC Davis School of Medicine
| |
Collapse
|
32
|
Kover ST, McCary LM, Ingram AM, Hatton DD, Roberts JE. Language development in infants and toddlers with fragile X syndrome: change over time and the role of attention. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2015; 120:125-44. [PMID: 25715182 PMCID: PMC5656241 DOI: 10.1352/1944-7558-120.2.125] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Fragile X syndrome (FXS) is associated with significant language and communication delays, as well as problems with attention. This study investigated early language abilities in infants and toddlers with FXS (n = 13) and considered visual attention as a predictor of those skills. We found that language abilities increased over the study period of 9 to 24 months, with moderate correlations among language assessments. In comparison to typically developing infants (n = 11), language skills were delayed beyond chronological age and developmental-level expectations. Aspects of early visual attention predicted later language ability. Atypical visual attention is an important aspect of the FXS phenotype with implications for early language development, particularly in the domain of vocabulary.
Collapse
|
33
|
Roelofs RL, Visser EM, Berger HJC, Prins JB, Van Schrojenstein Lantman-De Valk HMJ, Teunisse JP. Executive functioning in individuals with intellectual disabilities and autism spectrum disorders. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2015; 59:125-137. [PMID: 23931579 DOI: 10.1111/jir.12085] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/08/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND Executive functioning (EF) is important for adequate behavioural functioning and crucial for explaining symptoms of autism spectrum disorders (ASD) in individuals with normal intelligence, but is scarcely studied in individuals with ASD and intellectual disabilities (ID). We therefore study EF in an ID population by comparing performances on three frequently studied executive functions (shifting, inhibition and updating) between individuals with ASD and individuals without ASD. When studying ID populations, one should be aware of Spearman's Law of Diminishing Returns (SLODR), as it questions the possibility of measuring separate cognitive functions in ID populations. METHODS Six EF tasks were administered to 50 individuals with mild to borderline ID, of which half was diagnosed with ASD. In order to investigate the distinctness of the three executive functions in this ID sample, the results on the six EF tasks were subjected to principal components analysis (PCA). Subsequently, a multivariate analysis of variance (MANOVA) was performed to assess differences between the ASD and non-ASD group on shifting, inhibition and updating. RESULTS The PCA revealed the hypothesised EF trichotomy. MANOVA analysis showed no significant group differences on EF-performance. CONCLUSIONS Three separate executive functions were measured in this ID population, but despite much evidence that individuals with ASD display more behavioural problems and the proven relevance of EF in behavioural functioning, no significant group difference was found on shifting, inhibition or updating. After this first effort to achieve more insight into EF of individuals with ASD and ID the relation between behavioural problems and EF will require further study.
Collapse
Affiliation(s)
- R L Roelofs
- Department of Medical Psychology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; Centre of Excellence for Neuropsychiatry, Vincent van Gogh Institute for Psychiatry, Venray, The Netherlands
| | | | | | | | | | | |
Collapse
|
34
|
Lozano R, Rosero CA, Hagerman RJ. Fragile X spectrum disorders. Intractable Rare Dis Res 2014; 3:134-46. [PMID: 25606363 PMCID: PMC4298643 DOI: 10.5582/irdr.2014.01022] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/28/2014] [Indexed: 12/13/2022] Open
Abstract
The fragile X mental retardation 1 gene (FMR1), which codes for the fragile X mental retardation 1 protein (FMRP), is located at Xp27.3. The normal allele of the FMR1 gene typically has 5 to 40 CGG repeats in the 5' untranslated region; abnormal alleles of dynamic mutations include the full mutation (> 200 CGG repeats), premutation (55-200 CGG repeats) and the gray zone mutation (45-54 CGG repeats). Premutation carriers are common in the general population with approximately 1 in 130-250 females and 1 in 250-810 males, whereas the full mutation and Fragile X syndrome (FXS) occur in approximately 1 in 4000 to 1 in 7000. FMR1 mutations account for a variety of phenotypes including the most common monogenetic cause of inherited intellectual disability (ID) and autism (FXS), the most common genetic form of ovarian failure, the fragile X-associated primary ovarian insufficiency (FXPOI, premutation); and fragile X-associated tremor/ataxia syndrome (FXTAS, premutation). The premutation can also cause developmental problems including ASD and ADHD especially in boys and psychopathology including anxiety and depression in children and adults. Some premutation carriers can have a deficit of FMRP and some unmethylated full mutation individuals can have elevated FMR1 mRNA that is considered a premutation problem. Therefore the term "Fragile X Spectrum Disorder" (FXSD) should be used to include the wide range of overlapping phenotypes observed in affected individuals with FMR1 mutations. In this review we focus on the phenotypes and genotypes of children with FXSD.
Collapse
Affiliation(s)
- Reymundo Lozano
- UC Davis MIND Institute and Department of Pediatrics, UC Davis Medical Center, Sacramento, CA, USA
- Address correspondence to: Dr. Reymundo Lozano, UC Davis MIND Institute and Department of Pediatrics, UC Davis Medical Center, Sacramento, CA, USA. E-mail:
| | - Carolina Alba Rosero
- Instituto Colombiano del Sistema Nervioso, Clínica Montserrat, Bogotá D.C, Colombia
| | - Randi J Hagerman
- UC Davis MIND Institute and Department of Pediatrics, UC Davis Medical Center, Sacramento, CA, USA
| |
Collapse
|
35
|
Kazdoba TM, Leach PT, Silverman JL, Crawley JN. Modeling fragile X syndrome in the Fmr1 knockout mouse. Intractable Rare Dis Res 2014; 3:118-33. [PMID: 25606362 PMCID: PMC4298642 DOI: 10.5582/irdr.2014.01024] [Citation(s) in RCA: 168] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/28/2014] [Indexed: 11/05/2022] Open
Abstract
Fragile X Syndrome (FXS) is a commonly inherited form of intellectual disability and one of the leading genetic causes for autism spectrum disorder. Clinical symptoms of FXS can include impaired cognition, anxiety, hyperactivity, social phobia, and repetitive behaviors. FXS is caused by a CGG repeat mutation which expands a region on the X chromosome containing the FMR1 gene. In FXS, a full mutation (> 200 repeats) leads to hypermethylation of FMR1, an epigenetic mechanism that effectively silences FMR1 gene expression and reduces levels of the FMR1 gene product, fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein that is important for the regulation of protein expression. In an effort to further understand how loss of FMR1 and FMRP contribute to FXS symptomology, several FXS animal models have been created. The most well characterized rodent model is the Fmr1 knockout (KO) mouse, which lacks FMRP protein due to a disruption in its Fmr1 gene. Here, we review the behavioral phenotyping of the Fmr1 KO mouse to date, and discuss the clinical relevance of this mouse model to the human FXS condition. While much remains to be learned about FXS, the Fmr1 KO mouse is a valuable tool for understanding the repercussions of functional loss of FMRP and assessing the efficacy of pharmacological compounds in ameliorating the molecular and behavioral phenotypes relevant to FXS.
Collapse
Affiliation(s)
- Tatiana M. Kazdoba
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, CA, USA
- Address correspondence to: Dr. Tatiana M. Kazdoba, MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, Research II Building 96, 4625 2nd Avenue, Sacramento, CA 95817, USA. E-mail:
| | - Prescott T. Leach
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, CA, USA
| | - Jill L. Silverman
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, CA, USA
| | - Jacqueline N. Crawley
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California, Davis, School of Medicine, Sacramento, CA, USA
| |
Collapse
|
36
|
Benjamin DP, Mastergeorge AM, McDuffie AS, Kover ST, Hagerman RJ, Abbeduto L. Effects of labeling and pointing on object gaze in boys with fragile X syndrome: an eye-tracking study. RESEARCH IN DEVELOPMENTAL DISABILITIES 2014; 35:2658-72. [PMID: 25062097 PMCID: PMC4154990 DOI: 10.1016/j.ridd.2014.06.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 06/24/2014] [Accepted: 06/25/2014] [Indexed: 05/26/2023]
Abstract
We examined the visual processing of a social learning stimulus and the ways in which visual attention was distributed to objects as well as to the examiner's face during word learning under conditions that varied only in the presence or absence of a label. The goal of the current study, then, was to evaluate the effects of differentially providing pointing and labeling during exposure to a novel target object in males with fragile X syndrome (FXS) (n=14, ages 4.33-10.02), autism spectrum disorder (ASD) (n=17, ages 4.04-10.4), or typical development (TD) (n=18, ages 2.05-5.33). In particular, the present study examined attention to the examiner's face as well as target and distracter objects that were presented as video stimuli. An eye-tracker captured gaze to the video stimuli as they were shown in order to examine the way in which children with FXS, ASD, or TD distributed their gaze toward the examiner and the objects. Results indicated that no group showed increased gaze toward the target object compared to the distracter object. However, results revealed that participants with FXS showed significantly increased face gaze compared to the novel objects, whereas children with ASD and TD both showed similar amounts of relative gaze toward the face and objects. Furthermore, the act of pointing at the target object was found to increase gaze toward the target objects compared to when there was no pointing in all groups. Together, these findings suggest that social cues like those employed in a word-learning task, when presented with video, may relate to gaze in FXS in context- or task-dependent ways that are distinct from those expected during live interaction.
Collapse
Affiliation(s)
- David P Benjamin
- MIND Institute, University of California-Davis, United States; Department of Psychiatry and Behavioral Sciences, U.C. Davis School of Medicine, United States.
| | - Ann M Mastergeorge
- Division of Family Studies and Human Development, University of Arizona, United States.
| | - Andrea S McDuffie
- MIND Institute, University of California-Davis, United States; Department of Psychiatry and Behavioral Sciences, U.C. Davis School of Medicine, United States.
| | - Sara T Kover
- University of Washington, Seattle, WA, United States.
| | - Randi J Hagerman
- MIND Institute, University of California-Davis, United States; Department of Pediatrics, U.C. Davis School of Medicine, Sacramento, CA, United States.
| | - Leonard Abbeduto
- MIND Institute, University of California-Davis, United States; Department of Psychiatry and Behavioral Sciences, U.C. Davis School of Medicine, United States.
| |
Collapse
|
37
|
Turkstra LS, Abbeduto L, Meulenbroek P. Social cognition in adolescent girls with fragile x syndrome. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2014; 119:319-39. [PMID: 25007297 PMCID: PMC4285382 DOI: 10.1352/1944-7558-119.4.319] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This study aimed to characterize social cognition, executive functions (EFs), and everyday social functioning in adolescent girls with fragile X syndrome, and identify relationships among these variables. Participants were 20 girls with FXS and 20 age-matched typically developing peers. Results showed significant between-groups differences in social cognition, accounted for by differences in IQ and language. Within the FXS group, IQ and language were related to social cognition; parent-reported social functioning was related to language and EFs; and self-reported social functioning was generally good and not related to cognitive or social cognition variables. Results suggest that intervention might focus on managing language and cognitive contributions to social functioning, rather than social cognition, and underscore the importance of considering parent and adolescent perspectives.
Collapse
|
38
|
Phillips BA, Conners FA, Merrill E, Klinger MR. Rule-based category learning in Down syndrome. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2014; 119:220-34. [PMID: 24871791 PMCID: PMC5866920 DOI: 10.1352/1944-7558-119.3.220] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Rule-based category learning was examined in youths with Down syndrome (DS), youths with intellectual disability (ID), and typically developing (TD) youths. Two tasks measured category learning: the Modified Card Sort task (MCST) and the Concept Formation test of the Woodcock-Johnson-III ( Woodock, McGrew, & Mather, 2001 ). In regression-based analyses, DS and ID groups performed below the level expected for their nonverbal ability. In cross-sectional developmental trajectory analyses, results depended on the task. On the MCST, the DS and ID groups were similar to the TD group. On the Concept Formation test, the DS group had slower cross-sectional change than the other 2 groups. Category learning may be an area of difficulty for those with ID, but task-related factors may affect trajectories for youths with DS.
Collapse
|
39
|
Williams TA, Porter MA, Langdon R. Viewing social scenes: a visual scan-path study comparing fragile X syndrome and Williams syndrome. J Autism Dev Disord 2014; 43:1880-94. [PMID: 23224515 DOI: 10.1007/s10803-012-1737-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Fragile X syndrome (FXS) and Williams syndrome (WS) are both genetic disorders which present with similar cognitive-behavioral problems, but distinct social phenotypes. Despite these social differences both syndromes display poor social relations which may result from abnormal social processing. This study aimed to manipulate the location of socially salient information within scenes to investigate the visual attentional mechanisms of: capture, disengagement, and/or general engagement. Findings revealed that individuals with FXS avoid social information presented centrally, at least initially. The WS findings, on the other hand, provided some evidence that difficulties with attentional disengagement, rather than attentional capture, may play a role in the WS social phenotype. These findings are discussed in relation to the distinct social phenotypes of these two disorders.
Collapse
Affiliation(s)
- Tracey A Williams
- Department of Cognitive Science, ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, NSW, 2109, Australia.
| | | | | |
Collapse
|
40
|
Kramvis I, Mansvelder HD, Loos M, Meredith R. Hyperactivity, perseveration and increased responding during attentional rule acquisition in the Fragile X mouse model. Front Behav Neurosci 2013; 7:172. [PMID: 24312033 PMCID: PMC3836024 DOI: 10.3389/fnbeh.2013.00172] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 11/05/2013] [Indexed: 01/09/2023] Open
Abstract
Attentional deficits and executive function impairments are common to many neurodevelopmental disorders of intellectual disability and autism, including Fragile X syndrome (FXS). In the knockout mouse model for FXS, significant changes in synaptic plasticity and connectivity are found in the prefrontal cortex (PFC)-a prominent region for attentional processing and executive control. Given these alterations in PFC synaptic function, we tested whether adult Fragile X knockout mice exhibited corresponding impairments in inhibitory control, perseveration, and sustained attention. Furthermore, we investigated individual performance during attentional rule acquisition. Using the 5-choice serial reaction time task, our results show no impairments in inhibitory control and sustained attention. Fragile X knockout mice exhibited enhanced levels of correct and incorrect responding, as well as perseveration of responding during initial phases of rule acquisition, that normalized with training. For both knockout and wild type mice, pharmacological attenuation of metabotropic glutamate receptor 5 signaling did not affect response accuracy but reduced impulsive responses and increased omission errors. Upon rule reversal, Fragile X knockout mice made more correct and incorrect responses, similar to the initial phases of rule acquisition. Analogous to heightened activity upon novel rule acquisition, Fragile X knockout mice were transiently hyperactive in both a novel open field (OF) arena and novel home cage. Hyperactivity ceased with familiarization to the environment. Our findings demonstrate normal inhibitory control and sustained attention but heightened perseveration, responding, and hyperactivity during novel rule acquisition and during exposure to novel environments in Fragile X knockout mice. We therefore provide evidence for subtle but significant differences in the processing of novel stimuli in the mouse model for the FXS.
Collapse
Affiliation(s)
- Ioannis Kramvis
- Department of Integrative Neurophysiology, Centre for Neurogenomics and Cognitive Research, VU University Amsterdam Amsterdam, Netherlands ; Sylics (Synaptologics BV) Amsterdam, Netherlands
| | | | | | | |
Collapse
|
41
|
Berry-Kravis E, Hessl D, Abbeduto L, Reiss AL, Beckel-Mitchener A, Urv TK. Outcome measures for clinical trials in fragile X syndrome. J Dev Behav Pediatr 2013; 34:508-22. [PMID: 24042082 PMCID: PMC3784007 DOI: 10.1097/dbp.0b013e31829d1f20] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Progress in basic neuroscience has led to identification of molecular targets for treatment in fragile X syndrome (FXS) and other neurodevelopmental disorders; however, there is a gap in translation to targeted therapies in humans. One major obstacle to the demonstration of efficacy in human trials has been the lack of generally accepted endpoints to assess improvement in function in individuals with FXS. To address this problem, the National Institutes of Health convened a meeting of leading scientists and clinicians with the goal of identifying and standardizing outcome measures for use as potential endpoints in clinical trials in FXS. METHODS Participants in the meeting included FXS experts, experts in the design and implementation of clinical trials and measure development, and representatives from advocacy groups, industry, and federal agencies. RESULTS The group generated recommendations for optimal outcome measures in cognitive, behavioral, and biomarker/medical domains, including additional testing and validation of existing measures and development of new measures in areas of need. Although no one endpoint or set of endpoints could be identified that met all criteria as an optimal measure, recommendations are presented in this report. CONCLUSION The report is expected to guide the selection of measures in clinical trials and lead to the use of a more consistent battery of measures across trials. Furthermore, this will help to direct research toward gaps in the development of validated FXS-specific outcome measures and to assist with interpretation of clinical trial data by creating templates for measurement of treatment efficacy.
Collapse
Affiliation(s)
- Elizabeth Berry-Kravis
- Departments of Pediatrics, Neurological Sciences and Biochemistry Rush University Medical Center, Chicago, IL
| | - David Hessl
- Department of Psychiatry and Behavioral Sciences, University of California, Davis School of Medicine, Sacramento, CA
- MIND Institute, University of California, Davis Medical Center, Sacramento, CA
| | - Leonard Abbeduto
- Department of Psychiatry and Behavioral Sciences, University of California, Davis School of Medicine, Sacramento, CA
- MIND Institute, University of California, Davis Medical Center, Sacramento, CA
| | - Allan L. Reiss
- Center for Interdisciplinary Brain Sciences Research and Departments of Psychiatry and Behavioral Sciences, Radiology and Pediatrics Stanford University School of Medicine, Stanford, CA
| | | | - Tiina K. Urv
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | | |
Collapse
|
42
|
Martin GE, Losh M, Estigarribia B, Sideris J, Roberts J. Longitudinal profiles of expressive vocabulary, syntax and pragmatic language in boys with fragile X syndrome or Down syndrome. INTERNATIONAL JOURNAL OF LANGUAGE & COMMUNICATION DISORDERS 2013; 48:432-43. [PMID: 23889838 PMCID: PMC3926422 DOI: 10.1111/1460-6984.12019] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 02/01/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND Fragile X syndrome (FXS) and Down syndrome (DS) are the two leading genetic causes of intellectual disability, and FXS is the most common known genetic condition associated with autism. Both FXS and DS are associated with significant language impairment, but little is known about expressive language across domains over time or the role of autism in language development in FXS. AIMS To compare three domains of language production (vocabulary, syntax, pragmatics) over time within and across groups of boys with FXS with and without autism spectrum disorder (FXS-ASD, FXS-O), boys with DS, and typically developing (TD) boys. METHODS & PROCEDURES Twenty-nine boys with FXS-O, 40 boys with FXS-ASD, 34 boys with DS, and 48 younger TD boys of similar non-verbal mental age living in the United States participated in the study. The Antonyms, Syntax Construction and Pragmatic Judgment subtests of the Comprehensive Assessment of Spoken Language were administered annually over 3 years. OUTCOMES & RESULTS TD boys scored higher than all other groups on all three subtests; boys with FXS-O and FXS-ASD scored higher than boys with DS in Syntax Construction; and boys with FXS-O scored higher than boys with FXS-ASD in Pragmatic Judgment. Within-group patterns varied between groups. Overall, the TD group showed significantly more change over time than all other groups. CONCLUSIONS & IMPLICATIONS Findings suggest that expressive language skills and growth across various domains are more impaired in boys with FXS and DS than would be expected based on non-verbal mental age, that for boys with DS syntax is more impaired than would be expected based on intellectual disability, and that autism status affects pragmatic language in boys with FXS. Findings suggest that language production across domains should be addressed during assessment and intervention for boys with FXS and boys with DS, with differing group profiles also suggesting potentially different areas of focus.
Collapse
Affiliation(s)
- Gary E Martin
- Frank Porter Graham Child Development Institute, University of North Carolina at Chapel Hill, NC 27599, USA.
| | | | | | | | | |
Collapse
|
43
|
Effects of stimulus salience on touchscreen serial reversal learning in a mouse model of fragile X syndrome. Behav Brain Res 2013; 252:126-35. [PMID: 23747611 DOI: 10.1016/j.bbr.2013.05.060] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 05/24/2013] [Accepted: 05/28/2013] [Indexed: 12/20/2022]
Abstract
Fragile X syndrome (FXS) is the most common inherited form of intellectual disability in males and the most common genetic cause of autism. Although executive dysfunction is consistently found in humans with FXS, evidence of executive dysfunction in Fmr1 KO mice, a mouse model of FXS, has been inconsistent. One possible explanation for this is that executive dysfunction in Fmr1 KO mice, similar to humans with FXS, is only evident when cognitive demands are high. Using touchscreen operant conditioning chambers, male Fmr1 KO mice and their male wildtype littermates were tested on the acquisition of a pairwise visual discrimination followed by four serial reversals of the response rule. We assessed reversal learning performance under two different conditions. In the first, the correct stimulus was salient and the incorrect stimulus was non-salient. In the second and more challenging condition, the incorrect stimulus was salient and the correct stimulus was non-salient; this increased cognitive load by introducing conflict between sensory-driven (i.e., bottom-up) and task-dependent (i.e., top-down) signals. Fmr1 KOs displayed two distinct impairments relative to wildtype littermates. First, Fmr1 KOs committed significantly more learning-type errors during the second reversal stage, but only under high cognitive load. Second, during the first reversal stage, Fmr1 KOs committed significantly more attempts to collect a reward during the timeout following an incorrect response. These findings indicate that Fmr1 KO mice display executive dysfunction that, in some cases, is only evident under high cognitive load.
Collapse
|
44
|
Costanzo F, Varuzza C, Menghini D, Addona F, Gianesini T, Vicari S. Executive functions in intellectual disabilities: a comparison between Williams syndrome and Down syndrome. RESEARCH IN DEVELOPMENTAL DISABILITIES 2013; 34:1770-80. [PMID: 23501586 DOI: 10.1016/j.ridd.2013.01.024] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/28/2013] [Accepted: 01/28/2013] [Indexed: 05/14/2023]
Abstract
Executive functions are a set of high cognitive abilities that control and regulate other functions and behaviors and are crucial for successful adaptation. Deficits in executive functions are frequently described in developmental disorders, which are characterized by disadaptive behavior. However, executive functions are not widely examined in individuals with intellectual disability. The present study is aimed at evaluating the etiological specificity hypotheses pertaining to executive functions by comparing individuals with intellectual disability of different etiology, as Williams syndrome and Down syndrome, on different aspects of executive functions. To this aim a battery evaluating attention, short-term and working memory, planning, categorization, shifting and inhibition, was administered to 15 children, adolescents and adults with Williams syndrome, to 15 children, adolescents and adults with Down syndrome and to 16 mental-age-matched typically developing children. The two groups with intellectual disability showed impairment in a set of executive functions, as auditory sustained attention, visual selective attention, visual categorization and working memory, and preserved visual sustained attention, auditory selective attention and visual inhibition. However, a distinctive profile has been found between the two syndromic groups on other executive functions. While participants with Down syndrome were poor in shifting and verbal aspects of memory and inhibition, those with Williams syndrome were poor in planning. The specific weakness and straights on executive functions may support the etiological specificity hypothesis accounting for distinctive cognitive development syndrome-specific.
Collapse
Affiliation(s)
- Floriana Costanzo
- Department of Neuroscience, Bambino Gesù Children's Hospital, Piazza Sant'Onofrio 4, I-00165 Rome, Italy
| | | | | | | | | | | |
Collapse
|
45
|
Breckenridge K, Braddick O, Anker S, Woodhouse M, Atkinson J. Attention in Williams syndrome and Down's syndrome: Performance on the new early childhood attention battery. BRITISH JOURNAL OF DEVELOPMENTAL PSYCHOLOGY 2012; 31:257-69. [DOI: 10.1111/bjdp.12003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 09/09/2012] [Indexed: 12/01/2022]
Affiliation(s)
- Kate Breckenridge
- Visual Development Unit, Developmental Sciences Department; University College London; UK
| | - Oliver Braddick
- Department of Experimental Psychology; University of Oxford; UK
| | - Shirley Anker
- Visual Development Unit, Developmental Sciences Department; University College London; UK
| | | | - Janette Atkinson
- Visual Development Unit, Developmental Sciences Department; University College London; UK
| |
Collapse
|
46
|
Martin GE, Roberts JE, Helm-Estabrooks N, Sideris J, Vanderbilt J, Moskowitz L. Perseveration in the connected speech of boys with Fragile X syndrome with and without autism spectrum disorder. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2012; 117:384-99. [PMID: 22998486 PMCID: PMC3494464 DOI: 10.1352/1944-7558-117.5.384] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Verbal perseveration is a frequently reported language characteristic of males with Fragile X syndrome and may be a defining feature or hallmark of the syndrome. We compared the verbal perseveration of boys with Fragile X syndrome with (n = 29) and without (n = 30) autism spectrum disorder, boys with Down syndrome (n = 27), and typically developing boys (n = 25) at similar nonverbal mental ages. During a social interaction, boys with both Fragile X syndrome and autism spectrum disorder produced significantly more topic perseveration than all other groups. In social interaction as compared to narration, boys with Fragile X syndrome (regardless of autism status) produced significantly more topic perseveration. These findings suggest that autism status, as well as language sampling context, affect perseveration in boys with Fragile X syndrome.
Collapse
|
47
|
Losh M, Martin GE, Klusek J, Hogan-Brown AL, Sideris J. Social communication and theory of mind in boys with autism and fragile x syndrome. Front Psychol 2012; 3:266. [PMID: 22934085 PMCID: PMC3422728 DOI: 10.3389/fpsyg.2012.00266] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 07/09/2012] [Indexed: 11/13/2022] Open
Abstract
Impairments in the social use of language, or pragmatics, constitute a core characteristic of autism. Problems with pragmatic language have also been documented in fragile X syndrome (FXS), a monogenic condition that is the most common known genetic cause of autism. Evidence suggests that social cognitive ability, or theory of mind, may also be impaired in both conditions, and in autism, may importantly relate to pragmatic language ability. Given the substantial overlap observed in autism and FXS, this study aimed to better define those social-communicative phenotypes that overlap in these two conditions by comparing pragmatic language ability and theory of mind in children with idiopathic autism and children with FXS, with and without autism, as well as children with Down syndrome and typically developing controls. We further examined correlations between these cognitive-behavioral phenotypes and molecular genetic variation related to the Fragile X Mental Retardation-1 gene (FMR1) in the FXS group. Results indicated that children with idiopathic autism and those with FXS and autism performed comparably on direct-assessment measures of pragmatic language and theory of mind, whereas those with FXS only did not differ from controls. Theory of mind was related to pragmatic language ability in all groups. Pragmatic language and theory of mind also correlated with genetic variation at the FMR1 locus (Cytosine-Guanine-Guanine repeats and percent methylation). These results point toward substantial overlap in the social and language phenotypes in autism and FXS and suggest a molecular genetic basis to these phenotypic profiles.
Collapse
Affiliation(s)
- Molly Losh
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University Evanston, IL, USA
| | | | | | | | | |
Collapse
|
48
|
Knox A, Schneider A, Abucayan F, Hervey C, Tran C, Hessl D, Berry-Kravis E. Feasibility, reliability, and clinical validity of the Test of Attentional Performance for Children (KiTAP) in Fragile X syndrome (FXS). J Neurodev Disord 2012; 4:2. [PMID: 22958782 PMCID: PMC3374289 DOI: 10.1186/1866-1955-4-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 02/08/2012] [Indexed: 02/01/2023] Open
Abstract
Background Attention and inhibition are core executive-function deficits in FRagile X syndrome (FXS). This pilot study evaluated the feasibility, reproducibility, and clinical relevance of the KiTAP, a computer-based pictorial measure of attention and inhibition with an enchanted-castle theme, in an FXS cohort. Methods The 8-subtest KiTAP battery (as many subtests as each could perform) was given to 36 subjects with FXS, of variable age and cognitive/behavioral functioning, and 29 were retested, with an interval of 2 to 4 weeks between sessions. Subjects were rated by parents on the Aberrant Behavior Checklist-Community Edition (ABC-C) and Behavior Assessment System for Children, Second Edition (BASC-2). Feasibility, ceiling and basal effects, and data range and distribution analyses were used to eliminate outliers and invalid data points. Reproducibility of scores was analyzed using intraclass correlation coefficients (ICCs) and validity/clinical relevance was assessed by correlating KiTAP scores with ABC-C and BASC-2 scores. Results Most of the participants with FXS were able to complete the Alertness, Distractibility, Flexibility, and Go/NoGo subtests.About 50 to 60% completed the Visual Scanning and Vigilance subtests, and 20 to 25% completed the Sustained Attention and Divided Attention subtests. A panel of seven scores from four subtests were identified as feasible for most subjects, lacked excessive ceiling, basal, or learning effects, exhibited an acceptable range and distribution of scores, had good reproducibility (ICC > 0.7), and correlated with behavioral ratings for hyperactivity or attention (P < 0.01). Only minor differences in performance on the KiTAP were seen between mental age-matched cohorts of subjects with FXS and non-FXS intellectual disability. Conclusions The KiTAP can be administered to cohorts with FXS over a wide range of function with valid reproducible scores. With additional validation, it could represent a useful outcome measure for assessment of attention/executive-function abilities in clinical trials targeted to these core deficits in FXS.
Collapse
Affiliation(s)
- Andrew Knox
- Department of Pediatrics, Rush University Medical Center, 1725 West Harrison, Suite 718, Chicago, IL 60612, USA.
| | | | | | | | | | | | | |
Collapse
|
49
|
Van der Molen MJW, Van der Molen MW, Ridderinkhof KR, Hamel BCJ, Curfs LMG, Ramakers GJA. Attentional set-shifting in fragile X syndrome. Brain Cogn 2012; 78:206-17. [PMID: 22261226 DOI: 10.1016/j.bandc.2011.12.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Revised: 12/17/2011] [Accepted: 12/20/2011] [Indexed: 01/18/2023]
Abstract
The ability to flexibly adapt to the changing demands of the environment is often reported as a core deficit in fragile X syndrome (FXS). However, the cognitive processes that determine this attentional set-shifting deficit remain elusive. The present study investigated attentional set-shifting ability in fragile X syndrome males with the well-validated intra/extra dimensional set-shifting paradigm (IED) which offers detailed assessment of rule learning, reversal learning, and attentional set-shifting ability within and between stimulus dimensions. A novel scoring method for IED stage errors was employed to interpret set-shifting failure in terms of repetitive decision-making, distraction to irrelevance, and set-maintenance failure. Performance of FXS males was compared to typically developing children matched on mental age, adults matched on chronological age, and individuals with Down syndrome matched on both mental and chronological age. Results revealed that a significant proportion of FXS males already failed prior to the intra-dimensional set-shift stage, whereas all control participants successfully completed the stages up to the crucial extra-dimensional set-shift. FXS males showed a specific weakness in reversal learning, which was characterized by repetitive decision-making during the reversal of newly acquired stimulus-response associations in the face of simple stimulus configurations. In contrast, when stimulus configurations became more complex, FXS males displayed increased distraction to irrelevant stimuli. These findings are interpreted in terms of the cognitive demands imposed by the stages of the IED in relation to the alleged neural deficits in FXS.
Collapse
|
50
|
Van der Molen MJW, Van der Molen MW, Ridderinkhof KR, Hamel BCJ, Curfs LMG, Ramakers GJA. Auditory change detection in fragile X syndrome males: a brain potential study. Clin Neurophysiol 2011; 123:1309-18. [PMID: 22192499 DOI: 10.1016/j.clinph.2011.11.039] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 11/07/2011] [Accepted: 11/28/2011] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The present study investigated involuntary change detection in a two-tone pre-attentive auditory discrimination paradigm in order to better understand the information processing mechanisms underlying attention deficits in fragile X syndrome (FXS) males. METHODS Sixteen males with the FXS full mutation and 20 age-matched control participants (mean age 29 years) were presented with series of auditory stimuli consisting of standard and deviant tones while watching a silent movie. RESULTS Brain potentials recorded to the tones showed that N1 and P2, sensory evoked potentials, were significantly enhanced in FXS compared to age-matched control participants. In contrast to controls, the N1 to standard tones failed to show long-term habituation to stimulus repetition in FXS. Additionally, both mismatch negativity and P3a generation, reflecting automatic change detection and the involuntary switch of attention, respectively, were significantly attenuated in FXS males. CONCLUSIONS The current study demonstrates that auditory stimulus discrimination in the FXS brain is already compromised during the pre-attentive stages of information processing. Furthermore, the apparent pre-attentive information processing deficiencies in FXS coincide with a weakness in the involuntary engagement of attentional resources. SIGNIFICANCE The stimulus-driven information processing deficiencies in FXS might compromise information processing in several domains and, thus, present a key-deficit in FXS neurocognition.
Collapse
Affiliation(s)
- M J W Van der Molen
- Section of Developmental Psychology, Department of Developmental Psychology, University of Amsterdam, Amsterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|