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Ashburn SM, Matejko AA, Eden GF. Activation and functional connectivity of cerebellum during reading and during arithmetic in children with combined reading and math disabilities. Front Neurosci 2024; 18:1135166. [PMID: 38741787 PMCID: PMC11090247 DOI: 10.3389/fnins.2024.1135166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 02/06/2024] [Indexed: 05/16/2024] Open
Abstract
Background Reading and math constitute important academic skills, and as such, reading disability (RD or developmental dyslexia) and math disability (MD or developmental dyscalculia) can have negative consequences for children's educational progress. Although RD and MD are different learning disabilities, they frequently co-occur. Separate theories have implicated the cerebellum and its cortical connections in RD and in MD, suggesting that children with combined reading and math disability (RD + MD) may have altered cerebellar function and disrupted functional connectivity between the cerebellum and cortex during reading and during arithmetic processing. Methods Here we compared Control and RD + MD groups during a reading task as well as during an arithmetic task on (i) activation of the cerebellum, (ii) background functional connectivity, and (iii) task-dependent functional connectivity between the cerebellum and the cortex. Results The two groups (Control, RD + MD) did not differ for either task (reading, arithmetic) on any of the three measures (activation, background functional connectivity, task-dependent functional connectivity). Conclusion These results do not support theories that children's deficits in reading and math originate in the cerebellum.
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Affiliation(s)
| | | | - Guinevere F. Eden
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, United States
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Ashburn SM, Lynn Flowers D, Eden GF. A comparison of functional activation and connectivity of the cerebellum in adults and children during single word processing. Brain Lang 2023; 246:105346. [PMID: 37994829 PMCID: PMC10722870 DOI: 10.1016/j.bandl.2023.105346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/17/2023] [Accepted: 10/10/2023] [Indexed: 11/24/2023]
Abstract
Meta-analyses on reading show cerebellar activation in adults, but not children, suggesting a possible age-dependent role of the cerebellum in reading. However, the few studies that compare adults and children during reading report mixed cerebellar activation results. Here, we studied (i) cerebellar activation during implicit word processing in adults and children and (ii) functional connectivity (FC) between the cerebellum and left cortical regions involved in reading. First, both groups activated bilateral cerebellum for word processing when compared to fixation, but not when compared to the active control. There were no differences between adults and children. Second, we found intrinsic FC between several cerebellar seed regions and cortical target regions in adults and children, as well as between-group differences. However, task-modulated FC specific to word processing revealed no within- nor between-group results. Together this study does not provide support for a role of the cerebellum in word processing at either age.
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Affiliation(s)
- Sikoya M Ashburn
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, United States
| | - D Lynn Flowers
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, United States
| | - Guinevere F Eden
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, United States.
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3
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Turesky TK, Luetje MM, Eden GF. An fMRI study of finger movements in children with and without dyslexia. Front Neurosci 2023; 17:1135437. [PMID: 37274202 PMCID: PMC10233035 DOI: 10.3389/fnins.2023.1135437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 04/24/2023] [Indexed: 06/06/2023] Open
Abstract
Introduction Developmental dyslexia is a language-based reading disability, yet some have reported motor impairments, usually attributed to cerebellar dysfunction. Methods Using fMRI, we compared children with and without dyslexia during irregularly paced, left or right-hand finger tapping. Next, we examined seed-to-voxel intrinsic functional connectivity (iFC) using six seed regions of the motor system (left and right anterior lobe of the cerebellum, SM1 and SMA). Results A whole-brain task-evoked analysis revealed relatively less activation in the group with dyslexia in right anterior cerebellum during right hand tapping. For iFC, we found the group with dyslexia to have greater iFC between the right SM1 seed and a medial aspect of right postcentral gyrus for left hand tapping; and greater iFC between the left SM1 seed and left thalamus, as well as weaker local iFC around the left SM1 seed region for right hand tapping. Lastly, extracted activity and connectivity values that had been identified in these between-group comparisons were not correlated with measures of reading. Discussion We conclude that there are some aberrations in motor system function in children with dyslexia, but these are not tied to reading ability.
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Affiliation(s)
| | | | - Guinevere F. Eden
- Center for the Study of Learning, Georgetown University Medical Center, Washington, DC, United States
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Matejko AA, Lozano M, Schlosberg N, McKay C, Core L, Revsine C, Davis SN, Eden GF. The relationship between phonological processing and arithmetic in children with learning disabilities. Dev Sci 2023; 26:e13294. [PMID: 35727164 PMCID: PMC9768103 DOI: 10.1111/desc.13294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 01/21/2023]
Abstract
Phonological processing skills have not only been shown to be important for reading skills, but also for arithmetic skills. Specifically, previous research in typically developing children has suggested that phonological processing skills may be more closely related to arithmetic problems that are solved through fact retrieval (e.g., remembering the solution from memory) than procedural computation (e.g., counting). However, the relationship between phonological processing and arithmetic in children with learning disabilities (LDs) has not been investigated. Yet, understanding these relationships in children with LDs is especially important because it can help elucidate the cognitive underpinnings of math difficulties, explain why reading and math disabilities frequently co-occur, and provide information on which cognitive skills to target for interventions. In 63 children with LDs, we examined the relationship between different phonological processing skills (phonemic awareness, phonological memory, and rapid serial naming) and arithmetic. We distinguished between arithmetic problems that tend to be solved with fact retrieval versus procedural computation to determine whether phonological processing skills are differentially related to these two arithmetic processes. We found that phonemic awareness, but not phonological memory or rapid serial naming, was related to arithmetic fact retrieval. We also found no association between any phonological processing skills and procedural computation. These results converge with prior research in typically developing children and suggest that phonemic awareness is also related to arithmetic fact retrieval in children with LD. These results raise the possibility that phonemic awareness training might improve both reading and arithmetic fact retrieval skills. RESEARCH HIGHLIGHTS: Relationships between phonological processing and various arithmetic skills were investigated in children with learning disabilities (LDs) for the first time. We found phonemic awareness was related to arithmetic involving fact retrieval, but not to arithmetic involving procedural computation in LDs. The results suggest that phonemic awareness is not only important to skilled reading, but also to some aspects of arithmetic. These results raise the question of whether intervention in phonemic awareness might improve arithmetic fact retrieval skills.
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Affiliation(s)
- Anna A Matejko
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Melanie Lozano
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Nicole Schlosberg
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Cameron McKay
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
- Interdisciplinary Program in Neuroscience, Georgetown University, Washington, District of Columbia, USA
| | - Lucy Core
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Cambria Revsine
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Shelby N Davis
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Guinevere F Eden
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
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Schug AK, Brignoni‐Pérez E, Jamal NI, Eden GF. Gray matter volume differences between early bilinguals and monolinguals: A study of children and adults. Hum Brain Mapp 2022; 43:4817-4834. [PMID: 35848371 PMCID: PMC9582359 DOI: 10.1002/hbm.26008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/09/2022] [Accepted: 06/27/2022] [Indexed: 11/21/2022] Open
Abstract
Gray matter has been shown to be greater in early bilingual adults relative to monolingual adults in regions associated with language (Mechelli et al., 2004), and executive control (EC; Olulade et al., 2016). It is not known, however, if language experience-dependent differences in gray matter volume (GMV) exist in children. Further, any such differences are likely not to be the same as those observed in early bilingual adults, as children have had relatively shorter duration of dual-language exposure and/or less development of brain regions serving EC. We tested these predictions by comparing GMV in Spanish-English early bilingual and English monolingual children, and Spanish-English early bilingual and English monolingual adults (n = 122). Comparing only children revealed relatively more GMV in the bilinguals in bilateral frontal, right inferior frontal, and right superior parietal cortices (regions associated with EC). Bilinguals, however, had less GMV in left inferior parietal cortex (region associated with language). An ANOVA including these children with bilingual and monolingual adults revealed interactions of Language Background by Age Group. There were no regions of more GMV in bilinguals relative to monolinguals that were less pronounced in children than adults, despite the children's shorter dual-language experience. There were relative differences between bilingual and monolingual children that were more pronounced than those in adults in left precentral gyrus and right superior parietal lobule (close to, but not directly in areas associated with EC). Together, early bilingual children manifest relative differences in GMV, and, surprisingly, these do not diverge much from those observed in studies of bilingual adults.
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Affiliation(s)
- Alison K. Schug
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
- Interdisciplinary Program in NeuroscienceGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
| | - Edith Brignoni‐Pérez
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
- Interdisciplinary Program in NeuroscienceGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
| | - Nasheed I. Jamal
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
| | - Guinevere F. Eden
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
- Interdisciplinary Program in NeuroscienceGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
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Brignoni‐Pérez E, Jamal NI, Eden GF. Functional neuroanatomy of English word reading in early bilingual and monolingual adults. Hum Brain Mapp 2022; 43:4310-4325. [PMID: 35607841 PMCID: PMC9435003 DOI: 10.1002/hbm.25955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 02/28/2022] [Accepted: 04/19/2022] [Indexed: 12/02/2022] Open
Abstract
Skilled reading is important in daily life. While the understanding of the neurofunctional organization of this uniquely human skill has advanced significantly, it does not take into consideration the common bilingual experiences around the world. To examine the role of early bilingualism on the neural substrates supporting English word processing, we compared brain activity, as well as functional connectivity, in Spanish-English early bilingual adults (N = 25) and English monolingual adults (N = 33) during single-word processing. Activation analysis revealed no significant differences between the two groups. A seed-to-voxel analysis using eight a priori selected seed-regions (placed in regions known to be involved in reading) revealed relatively stronger functional connectivity in bilinguals between two sets of regions: left superior temporal gyrus seed positively with left lingual gyrus and left middle frontal gyrus seed negatively with left anterior cingulate cortex. Together these results suggest that an early Spanish-English bilingual experience does not modulate local brain activity for English word reading. It does, however, have some influence on the functional intercommunication between brain regions during reading, specifically in two regions associated with reading, which are functionally connected to those inside and outside of the reading network. We conclude that brain regions involved in processing English words are not that different in Spanish-English early bilingual adults relative to monolingual adult users of English.
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Affiliation(s)
- Edith Brignoni‐Pérez
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
- Interdisciplinary Program in NeuroscienceGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
| | - Nasheed I. Jamal
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
| | - Guinevere F. Eden
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
- Interdisciplinary Program in NeuroscienceGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
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Laws ML, Matejko AA, Lozano M, Napoliello E, Eden GF. Dorsal visual stream activity during coherent motion processing is not related to math ability or dyscalculia. Neuroimage Clin 2022; 35:103042. [PMID: 35580422 PMCID: PMC9117688 DOI: 10.1016/j.nicl.2022.103042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/12/2022] [Accepted: 05/08/2022] [Indexed: 11/16/2022]
Abstract
Math disability (MD) or developmental dyscalculia is a highly prevalent learning disability involving deficits in computation and arithmetic fact retrieval and is associated with dysfunction of parietal and prefrontal cortices. It has been suggested that dyscalculia (and other learning disabilities and developmental disorders) can be viewed in terms of a broader 'dorsal stream vulnerability,' which could explain a range of dorsal visual stream function deficits, including poor coherent visual motion perception. Behavioral evidence from two studies in typical children has linked performance on visual motion perception to math ability, and a third behavioral study reported poorer visual motion perception in a small group of children with MD compared to controls. Visual motion perception relies on the magnocellular-dominated dorsal stream, particularly its constituent area V5/MT. Here we used functional MRI to measure brain activity in area V5/MT during coherent visual motion processing to test its relationship with math ability. While we found bilateral activation in V5/MT in 66 children/adolescents with varied math abilities, we found no relationships between V5/MT activity and standardized math measures. Next, we selected a group of children/adolescents with MD (n = 23) and compared them to typically developing controls (n = 18), but found no differences in activity in V5/MT or elsewhere in the brain. We followed these frequentist statistics with Bayesian analyses, which favored null models in both studies. We conclude that dorsal stream function subserving visual motion processing in area V5/MT is not related to math ability, nor is it altered in those with the math disability dyscalculia.
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Affiliation(s)
- Marissa L Laws
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington DC, United States; Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington DC, United States
| | - Anna A Matejko
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington DC, United States
| | - Melanie Lozano
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington DC, United States
| | - Eileen Napoliello
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington DC, United States
| | - Guinevere F Eden
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington DC, United States; Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington DC, United States.
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Krafnick AJ, Napoliello EM, Flowers DL, Eden GF. The Role of Brain Activity in Characterizing Successful Reading Intervention in Children With Dyslexia. Front Neurosci 2022; 16:898661. [PMID: 35769700 PMCID: PMC9234261 DOI: 10.3389/fnins.2022.898661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/23/2022] [Indexed: 11/23/2022] Open
Abstract
Studies of reading intervention in dyslexia have shown changes in performance and in brain function. However, there is little consistency in the location of brain regions associated with successful reading gains in children, most likely due to variability/limitations in methodologies (study design, participant criteria, and neuroimaging procedures). Ultimately for the results to be meaningful, the intervention has to be successful, be assessed against a control, use rigorous statistics, and take biological variables (sex) into consideration. Using a randomized, crossover design, 31 children with dyslexia were assigned to a phonological- and orthographic-based tutoring period as well as a within-subjects control period to examine: (1) intervention-induced changes in behavior (reading performance) and in brain activity (during reading); and (2) behavioral and brain activity pre-intervention data that predicted intervention-induced gains in reading performance. We found gains in reading ability following the intervention, but not following the control period, with no effect of participants' sex. However, there were no changes in brain activity following the intervention (regardless of sex), suggesting that individual brain changes are too variable to be captured at the group level. Reading gains were not predicted by pre-intervention behavioral data, but were predicted by pre-intervention brain activity in bilateral supramarginal/angular gyri. Notably, some of this prediction was only found in females. Our results highlight the limitations of brain imaging in detecting the neural correlates of reading intervention in this age group, while providing further evidence for its utility in assessing eventual success of intervention, especially if sex is taken into consideration.
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Brignoni‐Pérez E, Matejko AA, Jamal NI, Eden GF. Functional neuroanatomy of arithmetic in monolingual and bilingual adults and children. Hum Brain Mapp 2021; 42:4880-4895. [PMID: 34255408 PMCID: PMC8449110 DOI: 10.1002/hbm.25587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 06/08/2021] [Accepted: 06/28/2021] [Indexed: 12/31/2022] Open
Abstract
Prior studies on the brain bases of arithmetic have not focused on (or even described) their participants' language backgrounds. Yet, unlike monolinguals, early bilinguals have the capacity to solve arithmetic problems in both of their two languages. This raises the question whether this ability, or any other experience that comes with being bilingual, affects brain activity for arithmetic in bilinguals relative to monolinguals. Here, we used functional magnetic resonance imaging to compare brain activity in 44 English monolinguals and 44 Spanish-English early bilinguals, during the solving of arithmetic problems in English. We used a factorial design to test for a main effect of bilingual Language Experience. Based on the known modulating roles of arithmetic operation and age, we used two arithmetic tasks (addition and subtraction) and studied two age groups (adults and children). When collapsing across operations and age, we found broad bilateral activation for arithmetic in both the monolingual group and the bilingual group. However, an analysis of variance revealed that there was no effect of Language Experience, nor an interaction of Language Experience with Operation or Age Group. Bayesian analyses within regions of interest chosen for their role in arithmetic further supported the finding of no effect of Language Experience on brain activity underlying arithmetic. We conclude that early bilingualism does not influence the functional neuroanatomy of simple arithmetic.
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Affiliation(s)
- Edith Brignoni‐Pérez
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
- Interdisciplinary Program in NeuroscienceGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
| | - Anna A. Matejko
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
| | - Nasheed I. Jamal
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
| | - Guinevere F. Eden
- Center for the Study of Learning, Department of PediatricsGeorgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
- Interdisciplinary Program in NeuroscienceGeorgetown UniversityWashingtonDistrict of ColumbiaUSA
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10
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Torre GA, Matejko AA, Eden GF. The relationship between brain structure and proficiency in reading and mathematics in children, adolescents, and emerging adults. Dev Cogn Neurosci 2020; 45:100856. [PMID: 32949854 PMCID: PMC7502824 DOI: 10.1016/j.dcn.2020.100856] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 08/26/2020] [Accepted: 09/04/2020] [Indexed: 11/18/2022] Open
Abstract
Behavioral and brain imaging studies speak to commonalities between reading and math. Here, we investigated relationships between individual differences in reading and math ability (single word reading and calculation) with brain anatomy (cortical thickness and surface area) in 342 participants between 6-22 years of age from the NIH Pediatric MRI Database. We found no brain-behavioral correlations in the full sample. When dividing the dataset into three age-specific subgroups, cortical thickness of the left supramarginal gyrus (SMG) and fusiform gyrus (FG) correlated with reading ability in the oldest subgroup (15-22 years) only. Next, we tested unique contributions of these educational measures to neuroanatomy. Single word reading ability, age, and their interaction all contributed unique variance to cortical thickness in the left SMG and intraparietal sulcus (IPS). Age, and the interaction between age and reading, predicted cortical thickness in the left FG. However, regression analyses for math ability showed no relationships with cortical thickness; nor for math or reading ability with surface area. Overall, our results demonstrate relationships between cortical thickness and reading ability in emerging adults, but not in younger age groups. Surprisingly, there were no such relationships with math, and hence no convergence between the reading and math results.
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Affiliation(s)
- G A Torre
- Center for the Study of Learning, Georgetown University Medical Center, Washington DC, United States; Department of Pediatrics, Georgetown University Medical Center, Washington DC, United States.
| | - A A Matejko
- Center for the Study of Learning, Georgetown University Medical Center, Washington DC, United States; Department of Pediatrics, Georgetown University Medical Center, Washington DC, United States
| | - G F Eden
- Center for the Study of Learning, Georgetown University Medical Center, Washington DC, United States; Department of Pediatrics, Georgetown University Medical Center, Washington DC, United States.
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11
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Brignoni-Perez E, Jamal NI, Eden GF. An fMRI study of English and Spanish word reading in bilingual adults. Brain Lang 2020; 202:104725. [PMID: 31978619 PMCID: PMC7461633 DOI: 10.1016/j.bandl.2019.104725] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 06/10/2023]
Abstract
Reading relies on a left-lateralized brain system, including occipito-temporal (OTC), temporo-parietal, and inferior frontal (IFC) cortices. Neuroimaging studies have investigated whether activation in these cortices is modulated by a language's orthographic depth (consistency of grapheme-to-phoneme conversion). In Spanish-English bilinguals, some but not all studies have reported activation differences between the two languages during reading. Here, we studied Spanish-English early bilingual adults living in the United States (N = 25; 17 females, 8 males). We examined local activity, functional connectivity, and spatially distributed activity patterns during English and Spanish word reading. We found overlap in local activity for the two languages in the left IFC, but no differences in activation between them and few differences in functional connectivity (none of which were in pairs of regions known to be involved in reading); yet, there were spatially distributed patterns of brain activity that differentiate English and Spanish in regions of bilateral cerebellum/left OTC, the left superior occipital gyrus, the left IFC, and the left medial frontal gyrus. Overall, we found no evidence for differences in local activation or functional connectivity during English versus Spanish word processing in regions known to be involved in reading, yet we found brain-based evidence that Spanish-English bilinguals distinguish between the two languages.
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Affiliation(s)
- Edith Brignoni-Perez
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, 4000 Reservoir Road NW, Washington, DC 20057, United States; Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road NW, Washington, DC 20057, United States
| | - Nasheed I Jamal
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road NW, Washington, DC 20057, United States
| | - Guinevere F Eden
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, 4000 Reservoir Road NW, Washington, DC 20057, United States; Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road NW, Washington, DC 20057, United States.
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12
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Ashburn SM, Flowers DL, Napoliello EM, Eden GF. Cerebellar function in children with and without dyslexia during single word processing. Hum Brain Mapp 2019; 41:120-138. [PMID: 31597004 PMCID: PMC7267899 DOI: 10.1002/hbm.24792] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 07/30/2019] [Accepted: 08/26/2019] [Indexed: 01/12/2023] Open
Abstract
The cerebellar deficit hypothesis of dyslexia posits that dysfunction of the cerebellum is the underlying cause for reading difficulties observed in this common learning disability. The present study used functional magnetic resonance imaging (fMRI) and a single word processing task to test for differences in activity and connectivity in children with (n = 23) and without (n = 23) dyslexia. We found cerebellar activity in the control group when word processing was compared to fixation, but not when it was compared to the active baseline task designed to reveal activity specific to reading. In the group with dyslexia there was no cerebellar activity for either contrasts and there were no differences when they were compared to children without dyslexia. Turning to functional connectivity (FC) in the controls, background FC (i.e., not specific to reading) was predominately found between the cerebellum and the occipitaltemporal cortex. In the group with dyslexia, there was background FC between the cerebellum and several cortical regions. When comparing the two groups, they differed in background FC in connections between the seed region right crus I and three left‐hemisphere perisylvian target regions. However, there was no task‐specific FC for word processing in either group and no between‐group differences. Together the results do not support the theory that the cerebellum is affected functionally during reading in children with dyslexia.
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Affiliation(s)
- Sikoya M Ashburn
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - D Lynn Flowers
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Eileen M Napoliello
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Guinevere F Eden
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, District of Columbia, USA
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13
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Glezer LS, Jiang X, Luetje MM, Napoliello EM, Kim J, Riesenhuber M, Eden GF. An fMRI-adaptation study of phonological and orthographic selectivity to written words in adults with poor reading skills. Brain Lang 2019; 191:1-8. [PMID: 30721792 DOI: 10.1016/j.bandl.2019.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 01/07/2019] [Accepted: 01/10/2019] [Indexed: 06/09/2023]
Abstract
Typical readers rely on two brain pathways for word processing in the left hemisphere: temporo-parietal cortex (TPC) and inferior frontal cortex (IFC), thought to subserve phonological decoding, and occipito-temporal cortex (OTC), including the "visual word form area" (VWFA), thought to subserve orthographic processing. How these regions are affected in developmental dyslexia has been a topic of intense research. We employed fMRI rapid adaptation (fMRI-RA) in adults with low reading skills to examine in independently-defined functional regions of interest (ROIs) phonological selectivity to written words in left TPC and IFC, and to orthographic selectivity to written words in OTC. Consistent with the phonological deficit hypothesis of dyslexia, we found responsivity but not selectivity to phonology, as accessed by written words, in the posterior superior temporal gyrus (pSTG) of the TPC. On the other hand, we found orthographic selectivity in the VWFA of the OTC. We also found selectivity to orthographic and not phonological processing in the IFG, a finding previously reported for typical readers. Together our results demonstrate that in adults with poor reading skills, selectivity to phonology is compromised in pSTG, while selectivity to orthography in the VWFA remains unaffected at this level of processing.
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Affiliation(s)
- Laurie S Glezer
- Department of Neuroscience, Georgetown University Medical Center, 4000 Reservoir Rd. NW, Washington, DC 20057, USA
| | - Xiong Jiang
- Department of Neuroscience, Georgetown University Medical Center, 4000 Reservoir Rd. NW, Washington, DC 20057, USA
| | - Megan M Luetje
- Department of Pediatrics, Georgetown University Medical Center, 4000 Reservoir Rd. NW, Washington, DC 20057, USA
| | - Eileen M Napoliello
- Department of Pediatrics, Georgetown University Medical Center, 4000 Reservoir Rd. NW, Washington, DC 20057, USA
| | - Judy Kim
- Department of Neuroscience, Georgetown University Medical Center, 4000 Reservoir Rd. NW, Washington, DC 20057, USA
| | - Maximilian Riesenhuber
- Department of Neuroscience, Georgetown University Medical Center, 4000 Reservoir Rd. NW, Washington, DC 20057, USA
| | - Guinevere F Eden
- Department of Pediatrics, Georgetown University Medical Center, 4000 Reservoir Rd. NW, Washington, DC 20057, USA.
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14
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Torre GAA, Eden GF. Relationships between gray matter volume and reading ability in typically developing children, adolescents, and young adults. Dev Cogn Neurosci 2019; 36:100636. [PMID: 30913497 PMCID: PMC6626657 DOI: 10.1016/j.dcn.2019.100636] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 03/06/2019] [Accepted: 03/08/2019] [Indexed: 01/20/2023] Open
Abstract
Reading is explicitly taught and foreshadows academic and vocational success. Studies comparing typical readers to those with developmental dyslexia have identified anatomical brain differences in bilateral temporo-parietal cortex, left temporo-occipital cortex, and bilateral cerebellum. Yet, it is unclear whether linear relationships exist between these brain structures and single real word reading ability in the general population. If dyslexia represents the lower end of the normal continuum, then relationships between gray matter volume (GMV) and reading ability would exist for all reading levels. Our study examined this question using voxel-based morphometry in a large sample (n = 404) of typically developing participants aged 6-22 derived from the NIH normative database. We tested correlations between individual GMV and single word reading and found none. After dividing this sample into groups based on age and on sex, we only found results in the group aged 15-22: positive correlations between GMV in left fusiform gyrus and reading, driven by females; and in right superior temporal gyrus in males. Multiple regressions also yielded no results, demonstrating that there is no general linear relationship between GMV and single real word reading ability. This provides an important context by which to interpret findings of GMV differences in dyslexia.
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Affiliation(s)
- Gabrielle-Ann A Torre
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, United States
| | - Guinevere F Eden
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, United States.
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15
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Turesky TK, Olulade OA, Luetje MM, Eden GF. An fMRI study of finger tapping in children and adults. Hum Brain Mapp 2018; 39:3203-3215. [PMID: 29611256 DOI: 10.1002/hbm.24070] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 02/08/2018] [Accepted: 03/22/2018] [Indexed: 11/09/2022] Open
Abstract
Functional brain imaging studies have characterized the neural bases of voluntary movement for finger tapping in adults, but equivalent information for children is lacking. When contrasted to adults, one would expect children to have relatively greater activation, reflecting compensation for an underdeveloped motor system combined with less experience in the execution of voluntary movement. To test this hypothesis, we acquired functional magnetic resonance imaging (fMRI) data on 17 healthy right-handed children (7.48 ± 0.66 years) and 15 adults (24.9 ± 2.9 years) while they performed an irregularly paced finger-tapping task in response to a visual cue (left- and right-hand examined separately). Whole-brain within-group analyses revealed that finger tapping in either age group and for either hand activated contralateral SM1, SMA, ipsilateral anterior cerebellum, and occipital cortices. We used an ANOVA factorial design to test for main effects of Age Group (children vs adults), Hand (left vs. right), and their interactions. For main effects of Age Group, children showed relatively greater activity in left SM1 (extending into bilateral SMA), and, surprisingly, adults exhibited relatively greater activity in right pre-SMA/SMA (extending into left pre-SMA/SMA), right lateral globus pallidus, left putamen, and right anterior cerebellum. The interaction of Age Group × Hand revealed that while both groups activated right SM1 during left finger tapping and exhibited signal decreases (i.e., below fixation baseline) during right finger tapping, both these responses were attenuated in children relative to adults. These data provide an important foundation by which to study children with motor disorders.
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Affiliation(s)
- Ted K Turesky
- Center for the Study of Learning, Georgetown University Medical Center, Washington, Washington D.C.,Interdisciplinary Program in Neuroscience, Georgetown University, Washington, Washington D.C
| | - Olumide A Olulade
- Center for the Study of Learning, Georgetown University Medical Center, Washington, Washington D.C
| | - Megan M Luetje
- Center for the Study of Learning, Georgetown University Medical Center, Washington, Washington D.C
| | - Guinevere F Eden
- Center for the Study of Learning, Georgetown University Medical Center, Washington, Washington D.C
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16
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Taylor CM, Olulade OA, Luetje MM, Eden GF. An fMRI study of coherent visual motion processing in children and adults. Neuroimage 2018; 173:223-239. [PMID: 29477442 DOI: 10.1016/j.neuroimage.2018.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 01/24/2018] [Accepted: 02/01/2018] [Indexed: 12/30/2022] Open
Abstract
There is a large corpus of brain imaging studies examining the dorsal visual pathway, especially area V5/MT during visual motion perception. However, despite evidence suggesting a protracted development of the dorsal visual stream, and a role of this pathway in neurodevelopmental disorders, V5/MT has not been characterized developmentally. Further, experiential factors such as reading acquisition may play a modulating role in any age-dependent changes. Here we used a coherent visual motion detection task to examine V5/MT activity and connectivity in typical participants in two studies: a Cross- Sectional Study comparing adults and children; and a Longitudinal Study of 2nd graders followed into 3rd grade. In the Cross-Sectional Study, a whole-brain analysis revealed no differences between the two groups, whereas a region of interest (ROI) approach identified greater activation in left (right trending) V5/MT in adults compared to children. However, when we measured V5/MT activation individually for each participant, children and adults showed no difference in the location or intensity of activation, although children did exhibit relatively larger extent of V5/MT activation bilaterally. There was also relatively greater functional connectivity in the children between left and right occipitotemporal cortex, including V5/MT. The Longitudinal Study revealed no changes in V5/MT activation for any measures of activation or functional connectivity from 2nd to 3rd grade. Finally, there was no evidence of an association between reading and V5/MT over time, nor predictive power of V5/MT activity for later reading. Together, our results indicate similar V5/MT activity across age groups, with relatively greater extent of V5/MT activation and functional connectivity in children relative to adults, bilaterally. These differences were not apparent over the time course of one year, suggesting that these developmental changes occur over a more protracted period.
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Affiliation(s)
- C M Taylor
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
| | - O A Olulade
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
| | - M M Luetje
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
| | - G F Eden
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA.
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17
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Turesky TK, Turkeltaub PE, Eden GF. An Activation Likelihood Estimation Meta-Analysis Study of Simple Motor Movements in Older and Young Adults. Front Aging Neurosci 2016; 8:238. [PMID: 27799910 PMCID: PMC5065996 DOI: 10.3389/fnagi.2016.00238] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/27/2016] [Indexed: 12/14/2022] Open
Abstract
The functional neuroanatomy of finger movements has been characterized with neuroimaging in young adults. However, less is known about the aging motor system. Several studies have contrasted movement-related activity in older versus young adults, but there is inconsistency among their findings. To address this, we conducted an activation likelihood estimation (ALE) meta-analysis on within-group data from older adults and young adults performing regularly paced right-hand finger movement tasks in response to external stimuli. We hypothesized that older adults would show a greater likelihood of activation in right cortical motor areas (i.e., ipsilateral to the side of movement) compared to young adults. ALE maps were examined for conjunction and between-group differences. Older adults showed overlapping likelihoods of activation with young adults in left primary sensorimotor cortex (SM1), bilateral supplementary motor area, bilateral insula, left thalamus, and right anterior cerebellum. Their ALE map differed from that of the young adults in right SM1 (extending into dorsal premotor cortex), right supramarginal gyrus, medial premotor cortex, and right posterior cerebellum. The finding that older adults uniquely use ipsilateral regions for right-hand finger movements and show age-dependent modulations in regions recruited by both age groups provides a foundation by which to understand age-related motor decline and motor disorders.
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Affiliation(s)
- Ted K Turesky
- Center for the Study of Learning, Georgetown University Medical Center, WashingtonDC, USA; Interdisciplinary Program in Neuroscience, Georgetown University, WashingtonDC, USA
| | - Peter E Turkeltaub
- Center for the Study of Learning, Georgetown University Medical Center, WashingtonDC, USA; Neurology Department, Georgetown University Medical Center, WashingtonDC, USA; Research Division, MedStar National Rehabilitation Hospital, WashingtonDC, USA
| | - Guinevere F Eden
- Center for the Study of Learning, Georgetown University Medical Center, Washington DC, USA
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18
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Evans TM, Flowers DL, Luetje MM, Napoliello E, Eden GF. Functional neuroanatomy of arithmetic and word reading and its relationship to age. Neuroimage 2016; 143:304-315. [PMID: 27566261 DOI: 10.1016/j.neuroimage.2016.08.048] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 08/19/2016] [Accepted: 08/22/2016] [Indexed: 10/21/2022] Open
Abstract
Arithmetic and written language are uniquely human skills acquired during early schooling and used daily. While prior studies have independently characterized the neural bases for arithmetic and reading, here we examine both skills in a single study to capture their shared and unique cognitive mechanisms, as well as the role of age/experience in modulating their neural representations. We used functional MRI in 7- to 29-year-olds who performed single-digit subtraction, single-digit addition, and single-word reading. Using a factorial design, we examined the main effects of Task (subtraction, addition, reading) and Age (as a continuous variable), and their interactions. A main effect of Task revealed preferential activation for subtraction in bilateral intraparietal sulci and supramarginal gyri, right insula, inferior frontal gyrus, and cingulate. The right middle temporal gyrus and left superior temporal gyrus were preferentially active for both addition and reading, and left fusiform gyrus was preferentially active for reading. A main effect of Age revealed increased activity in older participants in right angular gyrus, superior temporal sulcus, and putamen, and less activity in left supplementary motor area, suggesting a left frontal to right temporo-parietal shift of activity with increasing age/experience across all tasks. Interactions for Task by Age were found in right hippocampus and left middle frontal gyrus, with older age invoking greater activity for addition and at the same time less activity for subtraction and reading. Together, in a study conducted in the same participants using similar task and acquisition parameters, the results reveal the neural substrates of these educationally relevant cognitive skills in typical participants in the context of age/experience.
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Affiliation(s)
- Tanya M Evans
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA
| | - D Lynn Flowers
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA
| | - Megan M Luetje
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA
| | - Eileen Napoliello
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA
| | - Guinevere F Eden
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA.
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19
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Krafnick AJ, Tan LH, Flowers DL, Luetje MM, Napoliello EM, Siok WT, Perfetti C, Eden GF. Chinese Character and English Word processing in children's ventral occipitotemporal cortex: fMRI evidence for script invariance. Neuroimage 2016; 133:302-312. [PMID: 27012502 DOI: 10.1016/j.neuroimage.2016.03.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 03/09/2016] [Accepted: 03/10/2016] [Indexed: 11/15/2022] Open
Abstract
Learning to read is thought to involve the recruitment of left hemisphere ventral occipitotemporal cortex (OTC) by a process of "neuronal recycling", whereby object processing mechanisms are co-opted for reading. Under the same theoretical framework, it has been proposed that the visual word form area (VWFA) within OTC processes orthographic stimuli independent of culture and writing systems, suggesting that it is universally involved in written language. However, this "script invariance" has yet to be demonstrated in monolingual readers of two different writing systems studied under the same experimental conditions. Here, using functional magnetic resonance imaging (fMRI), we examined activity in response to English Words and Chinese Characters in 1st graders in the United States and China, respectively. We examined each group separately and found the readers of English as well as the readers of Chinese to activate the left ventral OTC for their respective native writing systems (using both a whole-brain and a bilateral OTC-restricted analysis). Critically, a conjunction analysis of the two groups revealed significant overlap between them for native writing system processing, located in the VWFA and therefore supporting the hypothesis of script invariance. In the second part of the study, we further examined the left OTC region responsive to each group's native writing system and found that it responded equally to Object stimuli (line drawings) in the Chinese-reading children. In English-reading children, the OTC responded much more to Objects than to English Words. Together, these results support the script invariant role of the VWFA and also support the idea that the areas recruited for character or word processing are rooted in object processing mechanisms of the left OTC.
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Affiliation(s)
- Anthony J Krafnick
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road, Building D Suite 150, Washington, DC 20057, USA.
| | - Li-Hai Tan
- State Key Laboratory of Brain and Cognitive Sciences, University of Hong Kong, Room 409, The Hong Kong Jockey Club Building for Interdisciplinary Research, Pokfulam, Hong Kong.
| | - D Lynn Flowers
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road, Building D Suite 150, Washington, DC 20057, USA.
| | - Megan M Luetje
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road, Building D Suite 150, Washington, DC 20057, USA.
| | - Eileen M Napoliello
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road, Building D Suite 150, Washington, DC 20057, USA.
| | - Wai-Ting Siok
- State Key Laboratory of Brain and Cognitive Sciences, University of Hong Kong, Room 409, The Hong Kong Jockey Club Building for Interdisciplinary Research, Pokfulam, Hong Kong.
| | - Charles Perfetti
- University of Pittsburgh, Learning Research and Development Center, 3939 O'Hara Street, Pittsburgh, PA 15260, USA.
| | - Guinevere F Eden
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road, Building D Suite 150, Washington, DC 20057, USA.
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20
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Abstract
The "bilingual advantage" theory stipulates that constant selection and suppression between 2 languages results in enhanced executive control (EC). Behavioral studies of EC in bilinguals have employed wide-ranging tasks and report some conflicting results. To avoid concerns about tasks, we employed a different approach, measuring gray matter volume (GMV) in adult bilinguals, reasoning that any EC-associated benefits should manifest as relatively greater frontal GMV. Indeed, Spanish-English-speaking bilinguals exhibited greater bilateral frontal GMV compared with English-speaking monolinguals. Was this observation attributable to the constant selection and inhibition of 2 spoken languages? To answer this question, we drew on bimodal bilinguals of American Sign Language (ASL) and English who, unlike unimodal bilinguals, can simultaneously use both languages and have been shown not to possess the EC advantage. In this group, there was no greater GMV when compared with monolinguals. Together these results provide neuroanatomical evidence in support of the bilingual advantage theory.
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Affiliation(s)
- O A Olulade
- Georgetown University Medical Center, Washington, DC 20007, USA Gallaudet University, Washington, DC 20002, USA
| | - N I Jamal
- Georgetown University Medical Center, Washington, DC 20007, USA
| | - D S Koo
- Georgetown University Medical Center, Washington, DC 20007, USA Gallaudet University, Washington, DC 20002, USA
| | - C A Perfetti
- University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - C LaSasso
- Gallaudet University, Washington, DC 20002, USA
| | - G F Eden
- Georgetown University Medical Center, Washington, DC 20007, USA Gallaudet University, Washington, DC 20002, USA
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21
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Olulade OA, Flowers DL, Napoliello EM, Eden GF. Dyslexic children lack word selectivity gradients in occipito-temporal and inferior frontal cortex. Neuroimage Clin 2015; 7:742-54. [PMID: 25844326 PMCID: PMC4375638 DOI: 10.1016/j.nicl.2015.02.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 02/20/2015] [Accepted: 02/20/2015] [Indexed: 11/19/2022]
Abstract
fMRI studies using a region-of-interest approach have revealed that the ventral portion of the left occipito-temporal cortex, which is specialized for orthographic processing of visually presented words (and includes the so-called "visual word form area", VWFA), is characterized by a posterior-to-anterior gradient of increasing selectivity for words in typically reading adults, adolescents, and children (e.g. Brem et al., 2006, 2009). Similarly, the left inferior frontal cortex (IFC) has been shown to exhibit a medial-to-lateral gradient of print selectivity in typically reading adults (Vinckier et al., 2007). Functional brain imaging studies of dyslexia have reported relative underactivity in left hemisphere occipito-temporal and inferior frontal regions using whole-brain analyses during word processing tasks. Hence, the question arises whether gradient sensitivities in these regions are altered in dyslexia. Indeed, a region-of-interest analysis revealed the gradient-specific functional specialization in the occipito-temporal cortex to be disrupted in dyslexic children (van der Mark et al., 2009). Building on these studies, we here (1) investigate if a word-selective gradient exists in the inferior frontal cortex in addition to the occipito-temporal cortex in normally reading children, (2) compare typically reading with dyslexic children, and (3) examine functional connections between these regions in both groups. We replicated the previously reported anterior-to-posterior gradient of increasing selectivity for words in the left occipito-temporal cortex in typically reading children, and its absence in the dyslexic children. Our novel finding is the detection of a pattern of increasing selectivity for words along the medial-to-lateral axis of the left inferior frontal cortex in typically reading children and evidence of functional connectivity between the most lateral aspect of this area and the anterior aspects of the occipito-temporal cortex. We report absence of an IFC gradient and connectivity between the lateral aspect of the IFC and the anterior occipito-temporal cortex in the dyslexic children. Together, our results provide insights into the source of the anomalies reported in previous studies of dyslexia and add to the growing evidence of an orthographic role of IFC in reading.
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Affiliation(s)
- O A Olulade
- Center for the Study of Learning, Georgetown University Medical Center, Washington, DC, USA
| | - D L Flowers
- Center for the Study of Learning, Georgetown University Medical Center, Washington, DC, USA
| | - E M Napoliello
- Center for the Study of Learning, Georgetown University Medical Center, Washington, DC, USA
| | - G F Eden
- Center for the Study of Learning, Georgetown University Medical Center, Washington, DC, USA
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22
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Evans TM, Flowers DL, Napoliello EM, Olulade OA, Eden GF. The functional anatomy of single-digit arithmetic in children with developmental dyslexia. Neuroimage 2014; 101:644-52. [PMID: 25067820 DOI: 10.1016/j.neuroimage.2014.07.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 06/14/2014] [Accepted: 07/16/2014] [Indexed: 12/20/2022] Open
Abstract
Some arithmetic procedures, such as addition of small numbers, rely on fact retrieval mechanisms supported by left hemisphere perisylvian language areas, while others, such as subtraction, rely on procedural-based mechanisms subserved by bilateral parietal cortices. Previous work suggests that developmental dyslexia, a reading disability, is accompanied by subtle deficits in retrieval-based arithmetic, possibly because of compromised left hemisphere function. To test this prediction, we compared brain activity underlying arithmetic problem solving in children with and without dyslexia during addition and subtraction operations using a factorial design. The main effect of arithmetic operation (addition versus subtraction) for both groups combined revealed activity during addition in the left superior temporal gyrus and activity during subtraction in the bilateral intraparietal sulcus, the right supramarginal gyrus and the anterior cingulate, consistent with prior studies. For the main effect of diagnostic group (dyslexics versus controls), we found less activity in dyslexic children in the left supramarginal gyrus. Finally, the interaction analysis revealed that while the control group showed a strong response in the right supramarginal gyrus for subtraction but not for addition, the dyslexic group engaged this region for both operations. This provides physiological evidence in support of the theory that children with dyslexia, because of disruption to left hemisphere language areas, use a less optimal route for retrieval-based arithmetic, engaging right hemisphere parietal regions typically used by good readers for procedural-based arithmetic. Our results highlight the importance of language processing for mathematical processing and illustrate that children with dyslexia have impairments that extend beyond reading.
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Affiliation(s)
- Tanya M Evans
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA
| | - D Lynn Flowers
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA; Wake Forest University Baptist Medical Center, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Eileen M Napoliello
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA
| | - Olumide A Olulade
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA
| | - Guinevere F Eden
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, Suite150 Building D, 4000 Reservoir Road NW, Washington, DC 20057, USA.
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23
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Abstract
Studies have converged in their findings of relatively less gray matter volume (GMV) in developmental dyslexia in bilateral temporoparietal and left occipitotemporal cortical regions. However, the interpretation of these results has been difficult. The reported neuroanatomical differences in dyslexia may be causal to the reading problems, following from, for example, neural migration errors that occurred during early human development and before learning to read. Alternatively, less GMV may represent the consequence of an impoverished reading experience, akin to the experience-dependent GMV differences attributed to illiterate compared with literate adults. Most likely, a combination of these factors is driving these observations. Here we attempt to disambiguate these influences by using a reading level-matched design, where dyslexic children were contrasted not only with age-matched controls, but also with younger controls who read at the same level as the dyslexics. Consistent with previous reports, dyslexics showed less GMV in multiple left and right hemisphere regions, including left superior temporal sulcus when compared with age-matched controls. However, not all of these differences emerged when dyslexics were compared with controls matched on reading abilities, with only right precentral gyrus GMV surviving this second analysis. When similar analyses were performed for white matter volume, no regions emerged from both comparisons. These results indicate that the GMV differences in dyslexia reported here and in prior studies are in large part the outcome of experience (e.g., disordered reading experience) compared with controls, with only a fraction of the differences being driven by dyslexia per se.
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Affiliation(s)
- Anthony J Krafnick
- Center for the Study of Learning, Georgetown University Medical Center, Washington, DC 20057, and Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina 27157
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24
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Abstract
UNLABELLED Developmental dyslexia is a reading disorder, yet deficits also manifest in the magnocellular-dominated dorsal visual system. Uncertainty about whether visual deficits are causal or consequential to reading disability encumbers accurate identification and appropriate treatment of this common learning disability. Using fMRI, we demonstrate in typical readers a relationship between reading ability and activity in area V5/MT during visual motion processing and, as expected, also found lower V5/MT activity for dyslexic children compared to age-matched controls. However, when dyslexics were matched to younger controls on reading ability, no differences emerged, suggesting that weakness in V5/MT may not be causal to dyslexia. To further test for causality, dyslexics underwent a phonological-based reading intervention. Surprisingly, V5/MT activity increased along with intervention-driven reading gains, demonstrating that activity here is mobilized through reading. Our results provide strong evidence that visual magnocellular dysfunction is not causal to dyslexia but may instead be consequential to impoverished reading. VIDEO ABSTRACT
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Affiliation(s)
- Olumide A Olulade
- Center for the Study of Learning, Georgetown University Medical Center, Washington, DC 20057, USA
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25
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Olulade OA, Flowers DL, Napolielo EM, Eden GF. Developmental differences for word processing in the ventral stream. Brain Lang 2013; 125:134-145. [PMID: 22564748 PMCID: PMC3426643 DOI: 10.1016/j.bandl.2012.04.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 03/28/2012] [Accepted: 04/07/2012] [Indexed: 05/31/2023]
Abstract
The visual word form system (VWFS), located in the occipito-temporal cortex, is involved in orthographic processing of visually presented words (Cohen et al., 2002). Recent fMRI studies in children and adults have demonstrated a gradient of increasing word-selectivity along the posterior-to-anterior axis of this system (Vinckier et al., 2007), yet whether this pattern is modified by the increased reading experience afforded by age is still in question. In this study, we employed fMRI and an implicit word-processing task, and then used a region of interest analysis approach along the occipito-temporal cortex to test the prediction that the selectivity for words along the extent of the VWFS differs between older experienced and younger novice readers. Our results showed differences between children and adults during word processing in the anterior left occipito-temporal cortex, providing evidence of developmental refinement for word recognition along the VWFS.
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Affiliation(s)
- Olumide A. Olulade
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road NW, Building D, Suite 150, Washington, DC, 20057, USA
| | - D. Lynn Flowers
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road NW, Building D, Suite 150, Washington, DC, 20057, USA
| | - Eileen M. Napolielo
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road NW, Building D, Suite 150, Washington, DC, 20057, USA
| | - Guinevere F. Eden
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road NW, Building D, Suite 150, Washington, DC, 20057, USA
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Evans TM, Flowers DL, Napoliello EM, Eden GF. Sex-specific gray matter volume differences in females with developmental dyslexia. Brain Struct Funct 2013; 219:1041-54. [PMID: 23625146 DOI: 10.1007/s00429-013-0552-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 04/09/2013] [Indexed: 01/18/2023]
Abstract
Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques, would generate the same findings. In a replication study of men, we obtained the same findings of less GMV in dyslexics in left middle/inferior temporal gyri and right postcentral/supramarginal gyri as reported in the literature. However, comparisons in women with and without dyslexia did not yield left hemisphere differences, and instead, we found less GMV in right precuneus and paracentral lobule/medial frontal gyrus. In boys, we found less GMV in left inferior parietal cortex (supramarginal/angular gyri), again consistent with previous work, while in girls differences were within right central sulcus, spanning adjacent gyri, and left primary visual cortex. Our investigation into anatomical variants in dyslexia replicates existing studies in males, but at the same time shows that dyslexia in females is not characterized by involvement of left hemisphere language regions but rather early sensory and motor cortices (i.e., motor and premotor cortex, primary visual cortex). Our findings suggest that models on the brain basis of dyslexia, primarily developed through the study of males, may not be appropriate for females and suggest a need for more sex-specific investigations into dyslexia.
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Affiliation(s)
- Tanya M Evans
- Center for the Study of Learning, Department of Pediatrics, Georgetown University Medical Center, BOX 571406, Suite 150, Building D, 4000 Reservoir Road, NW, Washington, DC, 20057, USA
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Purcell JJ, Turkeltaub PE, Eden GF, Rapp B. Examining the central and peripheral processes of written word production through meta-analysis. Front Psychol 2011; 2:239. [PMID: 22013427 PMCID: PMC3190188 DOI: 10.3389/fpsyg.2011.00239] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 09/01/2011] [Indexed: 11/24/2022] Open
Abstract
Producing written words requires “central” cognitive processes (such as orthographic long-term and working memory) as well as more peripheral processes responsible for generating the motor actions needed for producing written words in a variety of formats (handwriting, typing, etc.). In recent years, various functional neuroimaging studies have examined the neural substrates underlying the central and peripheral processes of written word production. This study provides the first quantitative meta-analysis of these studies by applying activation likelihood estimation (ALE) methods (Turkeltaub et al., 2002). For alphabet languages, we identified 11 studies (with a total of 17 experimental contrasts) that had been designed to isolate central and/or peripheral processes of word spelling (total number of participants = 146). Three ALE meta-analyses were carried out. One involved the complete set of 17 contrasts; two others were applied to subsets of contrasts to distinguish the neural substrates of central from peripheral processes. These analyses identified a network of brain regions reliably associated with the central and peripheral processes of word spelling. Among the many significant results, is the finding that the regions with the greatest correspondence across studies were in the left inferior temporal/fusiform gyri and left inferior frontal gyrus. Furthermore, although the angular gyrus (AG) has traditionally been identified as a key site within the written word production network, none of the meta-analyses found it to be a consistent site of activation, identifying instead a region just superior/medial to the left AG in the left posterior intraparietal sulcus. These meta-analyses and the discussion of results provide a valuable foundation upon which future studies that examine the neural basis of written word production can build.
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Affiliation(s)
- Jeremy J Purcell
- Department of Pediatrics, Center for the Study of Learning, Georgetown University Washington, DC, USA
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Cramer SC, Sur M, Dobkin BH, O'Brien C, Sanger TD, Trojanowski JQ, Rumsey JM, Hicks R, Cameron J, Chen D, Chen WG, Cohen LG, deCharms C, Duffy CJ, Eden GF, Fetz EE, Filart R, Freund M, Grant SJ, Haber S, Kalivas PW, Kolb B, Kramer AF, Lynch M, Mayberg HS, McQuillen PS, Nitkin R, Pascual-Leone A, Reuter-Lorenz P, Schiff N, Sharma A, Shekim L, Stryker M, Sullivan EV, Vinogradov S. Harnessing neuroplasticity for clinical applications. Brain 2011; 134:1591-609. [PMID: 21482550 PMCID: PMC3102236 DOI: 10.1093/brain/awr039] [Citation(s) in RCA: 604] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Neuroplasticity can be defined as the ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure, function and connections. Major advances in the understanding of neuroplasticity have to date yielded few established interventions. To advance the translation of neuroplasticity research towards clinical applications, the National Institutes of Health Blueprint for Neuroscience Research sponsored a workshop in 2009. Basic and clinical researchers in disciplines from central nervous system injury/stroke, mental/addictive disorders, paediatric/developmental disorders and neurodegeneration/ageing identified cardinal examples of neuroplasticity, underlying mechanisms, therapeutic implications and common denominators. Promising therapies that may enhance training-induced cognitive and motor learning, such as brain stimulation and neuropharmacological interventions, were identified, along with questions of how best to use this body of information to reduce human disability. Improved understanding of adaptive mechanisms at every level, from molecules to synapses, to networks, to behaviour, can be gained from iterative collaborations between basic and clinical researchers. Lessons can be gleaned from studying fields related to plasticity, such as development, critical periods, learning and response to disease. Improved means of assessing neuroplasticity in humans, including biomarkers for predicting and monitoring treatment response, are needed. Neuroplasticity occurs with many variations, in many forms, and in many contexts. However, common themes in plasticity that emerge across diverse central nervous system conditions include experience dependence, time sensitivity and the importance of motivation and attention. Integration of information across disciplines should enhance opportunities for the translation of neuroplasticity and circuit retraining research into effective clinical therapies.
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Affiliation(s)
- Steven C Cramer
- Department of Neurology, UC Irvine Medical Centre, 101 The City Drive South, Bldg 53, Rm 203, Orange, CA 92868-4280, USA.
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Jamal NI, Piche AW, Napoliello EM, Perfetti CA, Eden GF. Neural basis of single-word reading in Spanish-English bilinguals. Hum Brain Mapp 2011; 33:235-45. [PMID: 21391265 DOI: 10.1002/hbm.21208] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 08/24/2010] [Accepted: 10/20/2010] [Indexed: 11/12/2022] Open
Abstract
Brain imaging studies have identified a left-lateralized network of regions that are engaged when monolinguals read. However, for individuals who are native speakers of two languages, it is unclear whether this pattern of activity is maintained across both languages or if it deviates according to language-specific properties. We used functional magnetic resonance imaging to investigate single-word processing in Spanish and in English in 12 proficient early Spanish-English bilinguals matched in skill level in both languages. Word processing in Spanish engaged the left inferior frontal and left middle temporal gyri. Word processing in English activated the left inferior frontal, middle frontal, and fusiform gyri extending to inferior temporal gyrus and the right middle temporal gyrus extending into superior temporal sulcus. The comparison of reading in Spanish greater than reading in English revealed involvement of the left middle temporal gyrus extending into the superior temporal sulcus. English greater than Spanish, however, demonstrated greater engagement of the left middle frontal gyrus extending into the superior frontal gyrus. We conclude that although word processing in either language activates classical areas associated with reading, there are language-specific differences, which can be attributed to the disparity in orthographic transparency. English, an orthographically deep language, may require greater engagement of the frontal regions for phonological coding, whereas Spanish allows increased access to semantic processing via the left middle temporal areas. Together, these results suggest that bilinguals will show adjustments to the typical neural representation of reading as necessitated by the demands of the orthography.
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Affiliation(s)
- Nasheed I Jamal
- Center for the Study of Learning and Center for the Study of Visual Language and Visual Learning, Georgetown University, Washington, District of Columbia 20057, USA
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30
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Purcell JJ, Napoliello EM, Eden GF. A combined fMRI study of typed spelling and reading. Neuroimage 2010; 55:750-62. [PMID: 21109009 DOI: 10.1016/j.neuroimage.2010.11.042] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 11/09/2010] [Accepted: 11/12/2010] [Indexed: 10/18/2022] Open
Abstract
In this study we employed a novel technique to examine the neural basis of written spelling by having subjects touch-type single words on an fMRI compatible QWERTY keyboard. Additionally, in the same group of participants we determined if task-related signal changes associated with typed spelling were also co-localized with or separate from those for reading. Of particular interest were the left inferior frontal gyrus, left inferior parietal lobe as well as an area in the left occipitotemporal cortex termed the Visual Word Form Area (VWFA), each of which have been associated with both spelling and reading. Our results revealed that typed spelling was associated with a left hemisphere network of regions which included the inferior frontal gyrus, intraparietal sulcus, inferior temporal/fusiform gyrus, as well as a region in the superior/middle frontal gyrus, near Exner's area. A conjunction analysis of activation associated with spelling and reading revealed a significant overlap in the left inferior frontal gyrus and occipitotemporal cortex. Interestingly, within the occipitotemporal cortex just lateral and superior to the VWFA we identified an area that was selectively associated with spelling, as revealed by a direct comparison of the two tasks. These results demonstrate that typed spelling activates a predominantly left hemisphere network, a subset of which is functionally relevant to both spelling and reading. Further analysis revealed that the left occipitotemporal cortex contains regions with both conjoint and dissociable patterns of activation for spelling and reading.
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Affiliation(s)
- Jeremy J Purcell
- Center for the Study of Learning, Georgetown University, Washington, DC 20057, USA
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31
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Krafnick AJ, Flowers DL, Napoliello EM, Eden GF. Gray matter volume changes following reading intervention in dyslexic children. Neuroimage 2010; 57:733-41. [PMID: 21029785 DOI: 10.1016/j.neuroimage.2010.10.062] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 10/18/2010] [Accepted: 10/20/2010] [Indexed: 01/20/2023] Open
Abstract
Studies in children and adults with the reading disability developmental dyslexia have shown behavioral improvements after reading intervention. In another line of work, it has been shown that intensive training in a variety of cognitive and sensorimotor skills can result in changes in gray matter volume (GMV). This study examined changes in GMV following intensive reading intervention in children with dyslexia using voxel-based morphometry (VBM). Eleven dyslexic children underwent an eight week training focused on mental imagery, articulation and tracing of letters, groups of letters and words, which resulted in significant gains in reading skills. This was followed by an eight week null period (control) where no intervention was administered and no further significant gains in reading were observed. Structural scans were obtained before the intervention, after the intervention and after the null period. GMV increases between the first two time points were found in the left anterior fusiform gyrus/hippocampus, left precuneus, right hippocampus and right anterior cerebellum. However these areas did not change between time points two and three (control period), suggesting that the changes were specific to the intervention period. These results demonstrate for the first time that (1) training-induced changes in GMV can be observed in a pediatric sample and (2) reading improvements induced by intervention are accompanied by GMV changes.
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Affiliation(s)
- Anthony J Krafnick
- Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road, Building D Suite 150, Washington, DC 20057, USA.
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32
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Koo D, Crain K, LaSasso C, Eden GF. Phonological awareness and short-term memory in hearing and deaf individuals of different communication backgrounds. Ann N Y Acad Sci 2009; 1145:83-99. [PMID: 19076391 DOI: 10.1196/annals.1416.025] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Previous work in deaf populations on phonological coding and working memory, two skills thought to play an important role in the acquisition of written language skills, have focused primarily on signers or did not clearly identify the subjects' native language and communication mode. In the present study, we examined the effect of sensory experience, early language experience, and communication mode on the phonological awareness skills and serial recall of linguistic items in deaf and hearing individuals of different communicative and linguistic backgrounds: hearing nonsigning controls, hearing users of ASL, deaf users of ASL, deaf oral users of English, and deaf users of cued speech. Since many current measures of phonological awareness skills are inappropriate for deaf populations on account of the verbal demands in the stimuli or response, we devised a nonverbal phonological measure that addresses this limitation. The Phoneme Detection Test revealed that deaf cuers and oral users, but not deaf signers, performed as well as their hearing peers when detecting phonemes not transparent in the orthography. The second focus of the study examined short-term memory skills and found that in response to the traditional digit span as well as an experimental visual version, digit-span performance was similar across the three deaf groups, yet deaf subjects' retrieval was lower than that of hearing subjects. Our results support the claim (Bavelier et al., 2006) that lexical items processed in the visual-spatial modality are not as well retained as information processed in the auditory channel. Together these findings show that the relationship between working memory, phonological coding, and reading may not be as tightly interwoven in deaf students as would have been predicted from work conducted in hearing students.
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Affiliation(s)
- Daniel Koo
- Center for the Study of Learning, Georgetown University Medical Center, Washington, DC 20057, USA
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33
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Affiliation(s)
- José M Maisog
- Center for the Study of Learning, Georgetown University Medical Center, Washington, DC 20057, USA.
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34
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35
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36
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Given BK, Wasserman JD, Chari SA, Beattie K, Eden GF. A randomized, controlled study of computer-based intervention in middle school struggling readers. Brain Lang 2008; 106:83-97. [PMID: 18657684 DOI: 10.1016/j.bandl.2007.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Revised: 11/27/2007] [Accepted: 12/03/2007] [Indexed: 05/26/2023]
Abstract
The current study was conducted to test the premise that computer-based intervention that targets auditory temporal processing combined with language exercises (Fast ForWord) is effective in remediating children with disorders of language and reading. Sixty-five middle school struggling readers were randomly assigned to one of five groups and over a 12-week-period received one of the following interventions: (1) two phases of intervention with Fast ForWord (FFW, experimental group), (2) two phases of intervention with SuccessMaker (SM, active control group), (3) FFW followed by SM, (4) SM followed by FFW, or (5) no intervention beyond the regular class curriculum (developmental control group). Changes in reading, phonemic awareness, spelling and language skills were assessed via a repeated measures MANOVA. Results indicated significant within-subjects effects (i.e., change for all participants over time), but no between-subject group differences, failing to show that Fast ForWord resulted in any gains over and above those seen in the other groups.
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Affiliation(s)
- Barbara K Given
- Krasnow Institute for Advanced Study, George Mason University, 4400 University Drive, Fairfax, VA 22030-4444, USA.
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37
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Howard JH, Howard DV, Japikse KC, Eden GF. Dyslexics are impaired on implicit higher-order sequence learning, but not on implicit spatial context learning. Neuropsychologia 2005; 44:1131-44. [PMID: 16313930 DOI: 10.1016/j.neuropsychologia.2005.10.015] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Revised: 09/25/2005] [Accepted: 10/16/2005] [Indexed: 10/25/2022]
Abstract
Developmental dyslexia is characterized by poor reading ability and impairments on a range of tasks including phonological processing and processing of sensory information. Some recent studies have found deficits in implicit sequence learning using the serial reaction time task, but others have not. Other skills, such as global visuo-spatial processing may even be enhanced in dyslexics, although deficits have also been noted. The present study compared dyslexic and non-dyslexic college students on two implicit learning tasks, an alternating serial response time task in which sequential dependencies exist across non-adjacent elements and a spatial context learning task in which the global configuration of a display cues the location of a search target. Previous evidence indicates that these implicit learning tasks are based on different underlying brain systems, fronto-striatal-cerebellar circuits for sequence learning and medial temporal lobe for spatial context learning. Results revealed a double dissociation: dyslexics showed impaired sequence learning, but superior spatial context learning. Consistent with this group difference, there was a significant positive correlation between reading ability (single real and non-word reading) and sequence learning, but a significant negative correlation between these measures and spatial context learning. Tests of explicit knowledge confirmed that learning was implicit for both groups on both tasks. These findings indicate that dyslexic college students are impaired on some kinds of implicit learning, but not on others. The specific nature of their learning deficit is consistent with reports of physiological and anatomical differences for individuals with dyslexia in frontal and cerebellar structures.
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Affiliation(s)
- James H Howard
- Department of Psychology, The Catholic University of America, Washington, DC 20064, USA.
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38
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Abstract
Aloud reading of novel words is achieved by phonological decoding, a process in which grapheme-to-phoneme conversion rules are applied to "sound out" a word's spoken representation. Numerous brain imaging studies have examined the neural bases of phonological decoding by contrasting pseudoword (pronounceable nonwords) to real word reading. However, only a few investigations have examined pseudoword reading under both aloud and silent conditions, task parameters that are likely to significantly alter the functional anatomy of phonological decoding. Subjects participated in an fMRI study of aloud pseudoword, aloud real word, silent pseudoword, and silent real word reading. Using this two-by-two design, we examined effects of word-type (real words vs. pseudowords) and response-modality (silent vs. aloud) and their interactions. We found 1) four regions to be invariantly active across the four reading conditions: the anterior aspect of the left precentral gyrus (Brodmann's Area (BA) 6), and three areas within the left ventral occipitotemporal cortex; 2) a main effect of word-type (pseudowords > words) in left inferior frontal gyrus and left intraparietal sulcus; 3) a main effect of response-modality (aloud > silent) that included bilateral motor, auditory, and extrastriate cortex; and 4) a single left hemisphere extrastriate region showing a word-type by response-modality interaction effect. This region, within the posterior fusiform cortex at BA 19, was uniquely modulated by varying phonological processing demands. This result suggests that when reading, word forms are subject to phonological analysis at the point they are first recognized as alphabetic stimuli and BA 19 is involved in processing the phonological properties of words.
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Affiliation(s)
- Nicole A.E. Dietz
- Center for the Study of Learning and Department of Pediatrics, Georgetown University Medical Center, Washington, DC
| | - Karen M. Jones
- Center for the Study of Learning and Department of Pediatrics, Georgetown University Medical Center, Washington, DC
| | - Lynn Gareau
- Center for the Study of Learning and Department of Pediatrics, Georgetown University Medical Center, Washington, DC
| | - Thomas A. Zeffiro
- Center for Functional and Molecular Imaging and Department of Neurology, Georgetown University Medical Center, Washington, DC
| | - Guinevere F. Eden
- Center for the Study of Learning and Department of Pediatrics, Georgetown University Medical Center, Washington, DC
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Abstract
Language development entails four fundamental and interactive abilities: listening, speaking, reading, and writing. Over the past four decades, a large body of evidence has indicated that reading acquisition is strongly associated with a child's listening skills, particularly the child's sensitivity to phonological structures of spoken language. Furthermore, it has been hypothesized that the close relationship between reading and listening is manifested universally across languages and that behavioral remediation using strategies addressing phonological awareness alleviates reading difficulties in dyslexics. The prevailing view of the central role of phonological awareness in reading development is largely based on studies using Western (alphabetic) languages, which are based on phonology. The Chinese language provides a unique medium for testing this notion, because logographic characters in Chinese are based on meaning rather than phonology. Here we show that the ability to read Chinese is strongly related to a child's writing skills and that the relationship between phonological awareness and Chinese reading is much weaker than that in reports regarding alphabetic languages. We propose that the role of logograph writing in reading development is mediated by two possibly interacting mechanisms. The first is orthographic awareness, which facilitates the development of coherent, effective links among visual symbols, phonology, and semantics; the second involves the establishment of motor programs that lead to the formation of long-term motor memories of Chinese characters. These findings yield a unique insight into how cognitive systems responsible for reading development and reading disability interact, and they challenge the prominent phonological awareness view.
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Affiliation(s)
- Li Hai Tan
- Department of Linguistics, and Vice Chancellor's Office, University of Hong Kong, Pokfulam Road, Hong Kong, China
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40
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Eden GF, Jones KM, Cappell K, Gareau L, Wood FB, Zeffiro TA, Dietz NAE, Agnew JA, Flowers DL. Neural changes following remediation in adult developmental dyslexia. Neuron 2005; 44:411-22. [PMID: 15504323 DOI: 10.1016/j.neuron.2004.10.019] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2004] [Revised: 07/13/2004] [Accepted: 09/27/2004] [Indexed: 11/26/2022]
Abstract
Brain imaging studies have explored the neural mechanisms of recovery in adults following acquired disorders and, more recently, childhood developmental disorders. However, the neural systems underlying adult rehabilitation of neurobiologically based learning disabilities remain unexplored, despite their high incidence. Here we characterize the differences in brain activity during a phonological manipulation task before and after a behavioral intervention in adults with developmental dyslexia. Phonologically targeted training resulted in performance improvements in tutored compared to nontutored dyslexics, and these gains were associated with signal increases in bilateral parietal and right perisylvian cortices. Our findings demonstrate that behavioral changes in tutored dyslexic adults are associated with (1) increased activity in those left-hemisphere regions engaged by normal readers and (2) compensatory activity in the right perisylvian cortex. Hence, behavioral plasticity in adult developmental dyslexia involves two distinct neural mechanisms, each of which has previously been observed either for remediation of developmental or acquired reading disorders.
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Affiliation(s)
- Guinevere F Eden
- Georgetown University Medical Center, 4000 Reservoir Road, Building D, Suite 150, Washington, DC 20057, USA.
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41
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Agnew JA, Zeffiro TA, Eden GF. Left hemisphere specialization for the control of voluntary movement rate. Neuroimage 2004; 22:289-303. [PMID: 15110019 DOI: 10.1016/j.neuroimage.2003.12.038] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Revised: 12/18/2003] [Accepted: 12/23/2003] [Indexed: 11/20/2022] Open
Abstract
Although persuasive behavioral evidence demonstrates the superior dexterity of the right hand in most people under a variety of conditions, little is known about the neural mechanisms responsible for this phenomenon. As this lateralized superiority is most evident during the performance of repetitive, speeded movement, we used parametric rate variations to compare visually paced movement of the right and left hands. Twelve strongly right-handed subjects participated in a functional magnetic resonance imaging (fMRI) experiment involving variable rate thumb movements. For movements of the right hand, contralateral rate-related activity changes were identified in the precentral gyrus, thalamus, and posterior putamen. For left-hand movements, activity was seen only in the contralateral precentral gyrus, consistent with the existence of a rate-sensitive motor control subsystem involving the left, but not the right, medial premotor corticostriatal loop in right-handed individuals. We hypothesize that the right hemisphere system is less skilled at controlling variable-rate movements and becomes maximally engaged at a lower movement rate without further modulation. These findings demonstrate that right- and left-hand movements engage different neural systems to control movement, even during a relatively simple thumb flexion task. Specialization of the left hemisphere corticostriatal system for dexterity is reflected in asymmetric mechanisms for movement rate control.
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Affiliation(s)
- John A Agnew
- Department of Pediatrics and Center for the Study of Learning, Georgetown University Medical Center, 4000 Reservoir Road, Washington, DC 20057-1421, USA
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42
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Flowers DL, Jones K, Noble K, VanMeter J, Zeffiro TA, Wood FB, Eden GF. Attention to single letters activates left extrastriate cortex. Neuroimage 2004; 21:829-39. [PMID: 15006649 DOI: 10.1016/j.neuroimage.2003.10.002] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2003] [Revised: 09/01/2003] [Accepted: 10/06/2003] [Indexed: 10/26/2022] Open
Abstract
Brain imaging studies examining the component processes of reading using words, non-words, and letter strings frequently report task-related activity in the left extrastriate cortex. Processing of these linguistic materials involves varying degrees of semantic, phonological, and orthographic analysis that are sensitive to individual differences in reading skill and history. In contrast, single letter processing becomes automatized early in life and is not modulated by later linguistic experience to the same degree as are words. In this study, skilled readers attended to different aspects (single letters, symbols, and colors) of an identical stimulus set during separate sessions of functional magnetic resonance imaging (fMRI). Whereas activation in some portions of ventral extrastriate cortex was shared by attention to both alphabetic and non-alphabetic features, a letter-specific area was identified in a portion of left extrastriate cortex (Brodmann's Area 37), lateral to the visual word form area. Our results demonstrate that while minimizing activity related to word-level lexical properties, cortical responses to letter recognition can be isolated from figural and color characteristics of simple stimuli. The practical utility of this finding is discussed in terms of early identification of reading disability.
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Affiliation(s)
- D L Flowers
- Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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43
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Abstract
This study assessed the ability of seven children to accurately judge relative durations of auditory and visual stimuli before and after participation in a language remediation program. The goal of the intervention program is to improve the children's ability to detect and identify rapidly changing auditory stimuli, and thereby improve their language-related skills. Children showed improved accuracy on a test of auditory duration judgement following the intervention without analogous improvements in the visual domain, supporting the assertion that intensive training with modified speech improves auditory temporal discrimination. However, these improvements did not generalize to reading skills, as assessed by standard measures of phonological awareness and non-word reading.
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Affiliation(s)
- John A Agnew
- Center for the Study of Learning, Georgetown University Medical Center, USA
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44
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Abstract
Children with autism spectrum disorders in very rare cases display surprisingly advanced "hyperlexic" reading skills. Using functional magnetic resonance imaging (fMRI), we studied the neural basis of this precocious reading ability in a 9-year-old hyperlexic boy who reads 6 years in advance of his age. During covert reading, he demonstrated greater activity in the left inferior frontal and superior temporal cortices than both chronological age- and reading age-matched controls. Activity in the right inferior temporal sulcus was greater when compared to reading age-matched controls. These findings suggest that precocious reading is brought about by simultaneously drawing on both left hemisphere phonological and right hemisphere visual systems, reconciling the two prevailing, but seemingly contradictory, single hemisphere theories of hyperlexia. Hyperlexic reading is therefore associated with hyperactivation of the left superior temporal cortex, much in the same way as developmental dyslexia is associated with hypoactivation of this area.
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45
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Lin FH, McIntosh AR, Agnew JA, Eden GF, Zeffiro TA, Belliveau JW. Multivariate analysis of neuronal interactions in the generalized partial least squares framework: simulations and empirical studies. Neuroimage 2003; 20:625-42. [PMID: 14568440 DOI: 10.1016/s1053-8119(03)00333-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2002] [Revised: 04/28/2003] [Accepted: 05/21/2003] [Indexed: 10/27/2022] Open
Abstract
Identification of spatiotemporal interactions within/between neuron populations is critical for detection and characterization of large-scale neuronal interactions underlying perception, cognition, and behavior. Univariate analysis has been employed successfully in many neuroimaging studies. However, univariate analysis does not explicitly test for interactions between distributed areas of activity and is not sensitive to distributed responses across the brain. Multivariate analysis can explicitly test for multiple statistical models, including the designed paradigm, and allows for spatial and temporal model detection. Here, we investigate multivariate analysis approaches that take into consideration the 4D (time and space) covariance structure of the data. Principal component analysis (PCA) and independent component analysis (ICA) are two popular multivariate approaches with distinct mathematical constraints. Common difficulties in using these two different decompositions include the following: classification of the revealed components (task-related signal versus noise), overall signal-to-noise sensitivity, and the relatively low computational efficiency (multivariate analysis requires the entire raw data set and more time for model identification analysis). Using both Monte Carlo simulations and empirical data, we derived and tested the generalized partial least squares (gPLS) framework, which can incorporate both PCA and ICA decompositions with computational efficiency. The gPLS method explicitly incorporates the experimental design to simplify the identification of characteristic spatiotemporal patterns. We performed parametric modeling studies of a blocked-design experiment under various conditions, including background noise distribution, sampling rate, and hemodynamic response delay. We used a randomized grouping approach to manipulate the degrees of freedom of PCA and ICA in gPLS to characterize both paradigm coherent and transient brain responses. Simulation data suggest that in the gPLS framework, PCA mostly outperforms ICA as measured by the receiver operating curves (ROCs) in SNR from 0.01 to 100, the hemodynamic response delays from 0 to 3 TR in fMRI, background noise models of Guassian, sub-Gaussian, and super-Gaussian distributions and the number of observations from 5, 10, to 20 in each block of a six-block experiment. Further, due to selective averaging, the gPLS method performs robustly in low signal-to-noise ratio (<1) experiments. We also tested PCA and ICA using PLS in a simulated event-related fMRI data to show their similar detection. Finally, we tested our gPLS approach on empirical fMRI motor data. Using the randomized grouping method, we are able to identify both transient responses and consistent paradigm/model coherent components in the 10-epoch block design motor fMRI experiment. Overall, studies of synthetic and empirical data suggest that PLS analysis, using PCA decomposition, provides a stable and powerful tool for exploration of fMRI/behavior data.
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Affiliation(s)
- Fa-Hsuan Lin
- Harvard-MIT Division of Health Sciences and Technology, Charlestown, MA 02446, USA.
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46
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Turkeltaub PE, Gareau L, Flowers DL, Zeffiro TA, Eden GF. Development of neural mechanisms for reading. Nat Neurosci 2003; 6:767-73. [PMID: 12754516 DOI: 10.1038/nn1065] [Citation(s) in RCA: 439] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2002] [Accepted: 04/09/2003] [Indexed: 11/09/2022]
Abstract
The complexities of pediatric brain imaging have precluded studies that trace the neural development of cognitive skills acquired during childhood. Using a task that isolates reading-related brain activity and minimizes confounding performance effects, we carried out a cross-sectional functional magnetic resonance imaging (fMRI) study using subjects whose ages ranged from 6 to 22 years. We found that learning to read is associated with two patterns of change in brain activity: increased activity in left-hemisphere middle temporal and inferior frontal gyri and decreased activity in right inferotemporal cortical areas. Activity in the left-posterior superior temporal sulcus of the youngest readers was associated with the maturation of their phonological processing abilities. These findings inform current reading models and provide strong support for Orton's 1925 theory of reading development.
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Affiliation(s)
- Peter E Turkeltaub
- Georgetown University Medical Center, 4000 Reservoir Road, Building D Suite 150, Washington, DC 20057, USA
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47
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Abstract
Although developmental dyslexia is often defined as a language-based reading impairment not attributable to low intelligence or educational or socioeconomic limitations, the behavioral manifestations of dyslexia are not restricted to the realm of language. Functional brain imaging studies have shed light on physiological differences associated with poor reading both inside and outside the classical language areas of the brain. Concurrently, clinically useful tests that elicit these nonlinguistic deficits are few. Specifically, the integrity of the dorsal visual pathway, which predominantly projects to the parietal cortex, remains underinvestigated, lacking easily administered tests. Here we present the Clock Drawing Test (CDT), used to test the visuoconstructive ability of children with and without dyslexia and garden-variety poor readers. Compared to typically reading children, many children with dyslexia and some garden-variety poor readers showed significant left neglect, as measured by the distribution of figures drawn on the left clock face. In the poor readers with dyslexia, we observed spatial construction deficits like those of patients with acquired right-hemisphere lesions. The results suggest that in some children with dyslexia, right-hemisphere dysfunction may compound the phonological processing deficits attributed to the left hemisphere. The CDT provides an easy opportunity to assess skills known to be associated with right-hemisphere parietal function. This test can be easily administered to children for both clinical and research purposes.
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Affiliation(s)
- Guinevere F Eden
- Department for Pediatrics, Georgetown University Medical Center, Washington, DC 20057, USA.
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48
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Eden GF, Moats L. The role of neuroscience in the remediation of students with dyslexia. Nat Neurosci 2002; 5 Suppl:1080-4. [PMID: 12403991 DOI: 10.1038/nn946] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2002] [Accepted: 09/03/2002] [Indexed: 11/09/2022]
Abstract
Dyslexia is a specific learning disability that is neurobiological in origin. It is characterized by difficulties with accurate and/or fluent word recognition, spelling and decoding abilities. Research findings agree that these and other observed behavioral manifestations largely result from a deficit in the phonological component of language. However, conflicting theories on the exact nature of the phonological deficit have given rise to divergent treatment approaches. Recent advances in functional brain imaging and genetics have allowed these theories to be examined more closely. If implemented appropriately, commercial programs can be effective in identifying dyslexia. Treatment of dyslexia has been advanced through neuroscience, yet further study is needed to provide rigorous, reproducible findings that will sustain commercial approaches.
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Affiliation(s)
- Guinevere F Eden
- Center for the Study of Learning, Georgetown University Medical Center, Building D, 4000 Reservoir Road, Washington, DC 20057, USA.
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49
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Abstract
Intersubject variability and subtle differences in experimental design can lead to variable results in studies of cognitive processes such as reading. To accurately identify the neural processes associated with cognition and sensorimotor processing, meta-analytic methods capable of identifying areas of consistent activation among studies are useful. This paper describes a novel approach for combining published neuroimaging results from multiple studies, designed to maximize the quantification of interstudy concordance while minimizing the subjective aspects of meta-analysis. In this method, a localization probability distribution was modeled for each activation focus obtained from 11 PET studies of reading single words aloud, and the union of these distributions was taken to yield an activation likelihood estimate map for the brain. Significance was assessed via permutation analysis of randomly generated sets of foci. Regions of significant concordance were identified in bilateral motor and superior temporal cortices, pre-SMA, left fusiform gyrus, and the cerebellum. These meta-analytic results were validated by comparison with new fMRI data on aloud word reading in normal adult subjects. Excellent correspondence between the two statistical maps was observed, with fMRI maxima lying close to all meta-analysis peaks and statistical values at the peaks identified by the two techniques correlating strongly. This close correspondence between PET meta-analysis and fMRI results also demonstrates the validity of using fMRI for the study of language tasks involving overt speech responses. Advantages of this automated meta-analysis technique include quantification of the level of concordance at all brain locations and the provision for use of a threshold for statistical significance of concordance.
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Affiliation(s)
- Peter E Turkeltaub
- Center for the Study of Learning, Department of Neurology, Georgetown University Medical Center, Washington, DC 20007, USA
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50
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Lin FH, Agnew J, Zeffiro TA, Eden GF, McIntosh AR, Belliveau JW. Movement rate modulation of cortical motor systems investigated with partial least square analysis. Neuroimage 2000. [DOI: 10.1016/s1053-8119(00)91765-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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