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Gowen E, Jachim S, Subri S, Dickinson C, Hamblin-Pyke B, Warren PA. Collinear facilitation and contour integration in autistic adults: Examining lateral and feedback connectivity. Vision Res 2020; 177:56-67. [PMID: 32977182 DOI: 10.1016/j.visres.2020.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/24/2020] [Accepted: 08/17/2020] [Indexed: 01/20/2023]
Abstract
Alongside difficulties with communication and social interaction, autism is often accompanied by unusual sensory and perceptual experiences including enhanced visual performance on tasks that involve separating local parts from global context. This superiority may be the result of atypical integrative processing, involving feedback and lateral connections between visual neurons. The current study investigated the integrity of these connections in autistic adults by examining two psychophysics tasks that rely on these processes - collinear facilitation and contour integration. The relative contribution of feedback and lateral connectivity was studied by altering the timing of the target relative to the flankers in the collinear facilitation task, in 16 autistic and 16 non-autistic adults. There were no significant differences in facilitation between the autistic and non-autistic groups, indicating that for this task and participant sample, lateral and feedback connectivity appear relatively intact in autistic individuals. Contour integration was examined in a different group of 20 autistic and 18 non-autistic individuals, for open and closed contours to assess the closure effect (improved detection of closed compared to open contours). Autistic individuals showed a reduced closure effect at both short (150 ms) and longer (500 ms) stimulus presentation durations that was driven by better performance of the autistic group for the open contours. These results suggest that reduced closure in a simple contour detection paradigm is unlikely to be due to slower global processing. Reduced closure has implications for understanding sensory overload by contributing to reduced figure-ground segregation of salient visual features.
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Affiliation(s)
- Emma Gowen
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9PL, UK.
| | - Stephen Jachim
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9PL, UK
| | - Sabrina Subri
- Center of Optometry, Faculty of Health Sciences, Universiti Teknologi MARA, UiTM Cawangan Selangor, 42300 Puncak Alam, Selangor, Malaysia
| | - Christine Dickinson
- Division of Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Benjamin Hamblin-Pyke
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9PL, UK
| | - Paul A Warren
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9PL, UK
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van den Boomen C, Fahrenfort JJ, Snijders TM, Kemner C. Slow segmentation of faces in Autism Spectrum Disorder. Neuropsychologia 2019; 127:1-8. [PMID: 30768937 DOI: 10.1016/j.neuropsychologia.2019.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 10/27/2022]
Abstract
Atypical visual segmentation, affecting object perception, might contribute to face processing problems in Autism Spectrum Disorder (ASD). The current study investigated impairments in visual segmentation of faces in ASD. Thirty participants (ASD: 16; Control: 14) viewed texture-defined faces, houses, and homogeneous images, while electroencephalographic and behavioral responses were recorded. The ASD group showed slower face-segmentation related brain activity and longer segmentation reaction times than the control group, but no difference in house-segmentation related activity or behavioral performance. Furthermore, individual differences in face-segmentation but not house-segmentation correlated with score on the Autism Quotient. Segmentation is thus selectively impaired for faces in ASD, and relates to the degree of ASD traits. Face segmentation relates to recurrent connectivity from the fusiform face area (FFA) to the visual cortex. These findings thus suggest that atypical connectivity from the FFA might contribute to delayed face processing in ASD.
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Affiliation(s)
- C van den Boomen
- Dept. of Experimental Psychology, Helmholtz Institute, 3584 CS Utrecht, the Netherlands; Dept. of Developmental Psychology, Utrecht University, 3584 CS Utrecht, the Netherlands.
| | - J J Fahrenfort
- Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam, 1081 BT Amsterdam, the Netherlands
| | - T M Snijders
- Max Planck Institute for Psycholinguistics, 6500 AH Nijmegen, the Netherlands; Donders Institute for Brain, Cognition, and Behaviour; Donders Centre for Cognitive Neuroimaging, Radboud University, 6525 EN Nijmegen, the Netherlands
| | - C Kemner
- Dept. of Experimental Psychology, Helmholtz Institute, 3584 CS Utrecht, the Netherlands; Dept. of Developmental Psychology, Utrecht University, 3584 CS Utrecht, the Netherlands; Dept. of Child and Adolescent Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center, 3584 CX Utrecht, the Netherlands
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3
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Hannant P, Cassidy S, Van de Weyer R, Mooncey S. Sensory and motor differences in Autism Spectrum Conditions and developmental coordination disorder in children: A cross-syndrome study. Hum Mov Sci 2018; 58:108-118. [PMID: 29408162 DOI: 10.1016/j.humov.2018.01.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/19/2018] [Accepted: 01/19/2018] [Indexed: 11/18/2022]
Abstract
Recent research has shown that Developmental coordination disorder (DCD) can present with some similar symptomology as Autism Spectrum Conditions (ASC). This paper therefore explored the similarities and differences in coordination and sensory responsivity between DCD and ASC. 77 children took part: 42 (35 male, 7 female) with ASC (ages 7-21: mean age 12.23 years), 26 (19 male, 7 female) with DCD (ages 7-21; mean age 11.07 years) and 9 (2 male, 7 female) with ASC and DCD (ages 8-15; mean age 12.27). All groups completed a battery of validated parent report measures online that included motor coordination (DCDQ), sensory responsivity (SPC-R) and social communication measures (AQ). Results showed no significant differences in coordination, and some significant differences in sensory responsivity between ASC and DCD (increased visual and auditory responsivity and decreased proprioception). Exploratory analysis showed that these differences showed good validity in identifying the diagnosis of ASC and DCD. These results elucidate the underlying causes of motor coordination difficulties in both conditions. Specifically, ASC coordination difficulties appear linked to visual processing impairments, whilst DCD coordination difficulties appear to be linked to spatial processing. This may aid better diagnosis and intervention for these conditions.
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Affiliation(s)
- Penny Hannant
- Centre for Innovative Research Across the Life Course, Coventry University, UK.
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Hannant P, Cassidy S, Tavassoli T, Mann F. Sensorimotor Difficulties Are Associated with the Severity of Autism Spectrum Conditions. Front Integr Neurosci 2016; 10:28. [PMID: 27582694 PMCID: PMC4987345 DOI: 10.3389/fnint.2016.00028] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 08/02/2016] [Indexed: 01/30/2023] Open
Abstract
Present diagnostic criteria for autism spectrum conditions (ASC) include social communication and interaction difficulties, repetitive behavior and movement, and atypical sensory responsivity. Few studies have explored the influence of motor coordination and sensory responsivity on severity of ASC symptoms. In the current study, we explore whether sensory responsivity and motor coordination differences can account for the severity of autistic behaviors in children with ASC. Thirty-six children participated: 18 (13 male, 5 female) with ASC (ages 7-16: mean age = 9.93 years) and 18 (7 male, 11 female) typically developing (TD) children (ages 6-12; mean age = 9.16 years). Both groups completed a battery of assessments that included motor coordination, sensory responsivity, receptive language, non-verbal reasoning and social communication measures. Children with ASC also completed the Autism Diagnostic Observation Schedule (ADOS) and Autism Diagnostic Interview-Revised (ADI-R). Results showed that children with ASC scored significantly lower on receptive language, coordination, sensory responsivity and a sensorimotor subscale, Modulation of Activity (MoA) compared to the TD group. In the ASC group, MoA significantly predicted ASC severity across all ASC measures; receptive language and sensory responsivity significantly predicted parental reported autism measures; and coordination significantly predicted examiner observed reported scores. Additionally, specific associations were found between the somatosensory perceptive modalities and ASC severity. The results show that sensorimotor skills are associated with severity of ASC symptoms; furthering the need to research sensorimotor integration in ASC and also implying that diagnosis of ASC should also include the assessment of both coordination deficit and atypical sensory responsivity.
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Affiliation(s)
- Penelope Hannant
- Centre for Research in Psychology, Behaviour and Achievement, Coventry UniversityCoventry, UK
| | - Sarah Cassidy
- Centre for Research in Psychology, Behaviour and Achievement, Coventry UniversityCoventry, UK
| | - Teresa Tavassoli
- Seaver Autism Centre, Icahn School of Medicine, Mount SinaiNew York, NY, USA
| | - Francesca Mann
- School of Education, University of BirminghamBirmingham, UK
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5
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Hannant P, Tavassoli T, Cassidy S. The Role of Sensorimotor Difficulties in Autism Spectrum Conditions. Front Neurol 2016; 7:124. [PMID: 27559329 PMCID: PMC4978940 DOI: 10.3389/fneur.2016.00124] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/25/2016] [Indexed: 12/11/2022] Open
Abstract
In addition to difficulties in social communication, current diagnostic criteria for autism spectrum conditions (ASC) also incorporate sensorimotor difficulties, repetitive motor movements, and atypical reactivity to sensory input (1). This paper explores whether sensorimotor difficulties are associated with the development and maintenance of symptoms in ASC. First, studies have shown difficulties coordinating sensory input into planning and executing movement effectively in ASC. Second, studies have shown associations between sensory reactivity and motor coordination with core ASC symptoms, suggesting these areas each strongly influence the development of social and communication skills. Third, studies have begun to demonstrate that sensorimotor difficulties in ASC could account for reduced social attention early in development, with a cascading effect on later social, communicative and emotional development. These results suggest that sensorimotor difficulties not only contribute to non-social difficulties such as narrow circumscribed interests, but also to the development of social behaviors such as effectively coordinating eye contact with speech and gesture, interpreting others' behavior, and responding appropriately. Further research is needed to explore the link between sensory and motor difficulties in ASC and their contribution to the development and maintenance of ASC.
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Affiliation(s)
- Penelope Hannant
- Centre for Research in Psychology, Behaviour and Achievement, Coventry University, Coventry, UK
| | - Teresa Tavassoli
- Seaver Autism Centre, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sarah Cassidy
- Centre for Research in Psychology, Behaviour and Achievement, Coventry University, Coventry, UK
- Autism Research Centre, University of Cambridge, Cambridge, UK
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
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Behavioral evidence for a functional link between low- and mid-level visual perception in the autism spectrum. Neuropsychologia 2015; 77:380-6. [PMID: 26384775 DOI: 10.1016/j.neuropsychologia.2015.09.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 08/28/2015] [Accepted: 09/11/2015] [Indexed: 11/27/2022]
Abstract
BACKGROUND Most investigations of visuo-perceptual abilities in the Autism Spectrum (AS) are level-specific, using tasks that selectively solicit either lower- (i.e., spatial frequency sensitivity), mid- (i.e., pattern discrimination) or higher-level processes (i.e., face identification) along the visual hierarchy. Less is known about how alterations at one level of processing (i.e., low-level) interact with that of another (i.e., mid-level). The aim of this study was to assess whether manipulating the physical properties (luminance vs texture) of local contour elements of a mid-level, visual pattern interferes with the discrimination of that pattern in a differential manner for individuals with AS. METHODS Twenty-nine AS individuals and thirty control participants (range 14-27 years) were asked to discriminate between perfect circles and Radial Frequency Patterns (RFP) of two, three, five, and 10 radial frequencies (RF), or deformations along the pattern's contour. When RFP have few deformations (<five RF), a global, pattern analysis is needed for shape discrimination. Conversely, when RFP contain many deformations (≥10 RF), discrimination is dependent on the analysis of local deformations along the RFP contour. The effect of manipulating RF on RFP discrimination was assessed for RFP whose local contour elements were defined by either luminance or texture information, the latter previously found less efficiently processed in AS individuals. RESULTS Two separate mixed factorial ANOVAs [2 (Group)×4 (RF)] were conducted on mean deformation thresholds for luminance- and texture-defined conditions. A significant Group×RF interaction was found for the luminance-defined condition where thresholds were higher in the AS group for the two and three RF conditions; no between-group differences were found for the five and 10 RF conditions. A significant main effect of group was identified for the texture-defined condition, where mean thresholds were higher for the AS group across all RF conditions assessed (two, three, five and 10); a Group×RF interaction effect was not found. Performance for each RFP condition was not affected across group by either chronological age or intelligence, as measured by either Weschler scales or Raven Progressive Matrices. CONCLUSIONS The ability of AS individuals to discriminate a circular pattern is differentially affected by the availability (number of deformations along the RFP contour) and type (luminance vs texture) of local, low-level elements defining its contour. Performance is unaffected in AS when RFP discrimination is dependent on the analysis of local deformations of luminance-defined contour elements, but decreased across all RF conditions when local contour elements are texture-defined. These results suggest that efficient pattern perception in AS is functionally related to the efficacy with which its local elements are processed, indicative of an early origin for altered mid-level, pattern perception in AS.
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Smith D, Ropar D, Allen HA. Visual integration in autism. Front Hum Neurosci 2015; 9:387. [PMID: 26190994 PMCID: PMC4486830 DOI: 10.3389/fnhum.2015.00387] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 06/18/2015] [Indexed: 11/13/2022] Open
Abstract
Atypical integration is a topic of debate in the autism literature. Some theories suggest that altered perception in autism spectrum disorder (ASD) is due to a failure to integrate information from meaningful context into the final percept, whereas others suggest that integration of low-level features is impaired. Empirical research which forms the basis for these theories has failed to account for higher-level influences not inherent in the stimuli (i.e., instructions and goals) and assess integration at both lower and higher perceptual levels within the same task. Here, we describe how perceived expectations and goals of a task can modulate the processing of low-level visual input via the medial prefrontal cortex (mPFC). We then go on to illustrate how future research might assess the relative contribution of both low and high-level processes using the same paradigm. We conclude by recommending that when results appear conflicting, consideration of the relative strength of low-level input vs. feedback or high-level processes may prove helpful. Importantly, research in this area needs to more broadly consider the various influences on perception, and find better ways to assess the contributions of early and later visual processes.
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Affiliation(s)
- Danielle Smith
- School of Psychology, University of Nottingham Nottingham, UK
| | - Danielle Ropar
- School of Psychology, University of Nottingham Nottingham, UK
| | - Harriet A Allen
- School of Psychology, University of Nottingham Nottingham, UK
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8
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Eussen MLJM, Gool ARV, Louwerse A, Verhulst FC, Greaves-Lord K. Superior Disembedding Performance in Childhood Predicts Adolescent Severity of Repetitive Behaviors: A Seven Years Follow-Up of Individuals With Autism Spectrum Disorder. Autism Res 2015; 9:282-91. [DOI: 10.1002/aur.1510] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 05/20/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Mart L. J. M. Eussen
- Department of Child and Adolescent Psychiatry/Psychology; Erasmus Medical University Center/Sophia Children's Hospital; Rotterdam The Netherlands
- Yulius Academy; Dordrecht The Netherlands
| | | | - Anneke Louwerse
- Department of Child and Adolescent Psychiatry/Psychology; Erasmus Medical University Center/Sophia Children's Hospital; Rotterdam The Netherlands
- Yulius Academy; Dordrecht The Netherlands
| | - Frank C. Verhulst
- Department of Child and Adolescent Psychiatry/Psychology; Erasmus Medical University Center/Sophia Children's Hospital; Rotterdam The Netherlands
| | - Kirstin Greaves-Lord
- Department of Child and Adolescent Psychiatry/Psychology; Erasmus Medical University Center/Sophia Children's Hospital; Rotterdam The Netherlands
- Yulius Academy; Dordrecht The Netherlands
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9
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Jachim S, Warren PA, McLoughlin N, Gowen E. Collinear facilitation and contour integration in autism: evidence for atypical visual integration. Front Hum Neurosci 2015; 9:115. [PMID: 25805985 PMCID: PMC4354276 DOI: 10.3389/fnhum.2015.00115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/16/2015] [Indexed: 11/13/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interaction, atypical communication and a restricted repertoire of interests and activities. Altered sensory and perceptual experiences are also common, and a notable perceptual difference between individuals with ASD and controls is their superior performance in visual tasks where it may be beneficial to ignore global context. This superiority may be the result of atypical integrative processing. To explore this claim we investigated visual integration in adults with ASD (diagnosed with Asperger's Syndrome) using two psychophysical tasks thought to rely on integrative processing-collinear facilitation and contour integration. We measured collinear facilitation at different flanker orientation offsets and contour integration for both open and closed contours. Our results indicate that compared to matched controls, ASD participants show (i) reduced collinear facilitation, despite equivalent performance without flankers; and (ii) less benefit from closed contours in contour integration. These results indicate weaker visuospatial integration in adults with ASD and suggest that further studies using these types of paradigms would provide knowledge on how contextual processing is altered in ASD.
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Affiliation(s)
- Stephen Jachim
- Faculty of Life Sciences, University of ManchesterManchester, UK
| | - Paul A. Warren
- Psychological Sciences, University of ManchesterManchester, UK
| | - Niall McLoughlin
- Faculty of Life Sciences, University of ManchesterManchester, UK
| | - Emma Gowen
- Faculty of Life Sciences, University of ManchesterManchester, UK
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10
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Marsh T, Boag S. Evolutionary and differential psychology: conceptual conflicts and the path to integration. Front Psychol 2013; 4:655. [PMID: 24065949 PMCID: PMC3779804 DOI: 10.3389/fpsyg.2013.00655] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 09/03/2013] [Indexed: 11/13/2022] Open
Abstract
Evolutionary psychology has seen the majority of its success exploring adaptive features of the mind believed to be ubiquitous across our species. This has given rise to the belief that the adaptationist approach has little to offer the field of differential psychology, which concerns itself exclusively with the ways in which individuals systematically differ. By framing the historical origins of both disciplines, and exploring the means through which they each address the unique challenges of psychological description and explanation, the present article identifies the conceptual and theoretical problems that have kept differential psychology isolated not only from evolutionary psychology, but from explanatory approaches in general. Paying special attention to these conceptual problems, the authors review how these difficulties are being overcome by contemporary evolutionary research, and offer instructive suggestions concerning how differential researchers (and others) can best build upon these innovations.
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Affiliation(s)
- Tim Marsh
- Department of Psychology, Macquarie UniversitySydney, NSW, Australia
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11
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van den Boomen C, Lamme VA, Kemner C. Parallel development of ERP and behavioural measurements of visual segmentation. Dev Sci 2013; 17:1-10. [DOI: 10.1111/desc.12093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 05/09/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Carlijn van den Boomen
- Department of Experimental Psychology; Helmholtz Institute; Utrecht The Netherlands
- Department of Developmental Psychology; Utrecht University; The Netherlands
| | - Victor A.F. Lamme
- Brain and Cognition; Department of Psychology; Faculty of Behavioral and Societal Sciences; University of Amsterdam; The Netherlands
| | - Chantal Kemner
- Department of Experimental Psychology; Helmholtz Institute; Utrecht The Netherlands
- Department of Developmental Psychology; Utrecht University; The Netherlands
- Rudolf Magnus Institute of Neuroscience; Department of Child and Adolescent Psychiatry; University Medical Centre; Utrecht The Netherlands
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Abstract
Conscious perception is not the result of passively processing sensory input, but to large extent of active inference based on previous knowledge. This process of inference does go astray from time to time, and may lead to illusory perception: sometimes people see things that are not there. In a recent study we have shown that this inference may also be influenced by mood. Here we present some additional data, suggesting that illusory percepts are the result of increased top-down processing, which is normally helpful in detecting real stimuli. Finally, we speculate on a possible function of mood-dependent modulation of this top-down processing in social perception in particular.
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Affiliation(s)
- Jacob Jolij
- Vision and Cognition Group, Department of Experimental Psychology; Faculty of Behavioural and Social Sciences; University of Groningen; Groningen, The Netherlands
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Chen Y, Norton DJ, McBain R, Gold J, Frazier JA, Coyle JT. Enhanced local processing of dynamic visual information in autism: evidence from speed discrimination. Neuropsychologia 2012; 50:733-9. [PMID: 22261399 PMCID: PMC4094132 DOI: 10.1016/j.neuropsychologia.2012.01.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 12/08/2011] [Accepted: 01/04/2012] [Indexed: 01/08/2023]
Abstract
An important issue for understanding visual perception in autism concerns whether individuals with this neurodevelopmental disorder possess an advantage in processing local visual information, and if so, what is the nature of this advantage. Perception of movement speed is a visual process that relies on computation of local spatiotemporal signals but requires the comparison of information from more than a single spatial location or temporal point. This study examined speed discrimination in adolescents (ages 13-18 years old) with autism spectrum disorders (ASD). Compared to healthy controls (n=17), individuals with ASD (n=19) showed similarly precise speed discrimination when two comparison motion stimuli (random dot patterns) were presented closely in time (0.5s). With a longer temporal interval (3s) between the motion stimuli, individuals with ASD outperformed healthy controls on speed discrimination. On a second task--global motion perception--in which individuals were asked to detect coherent motion, individuals with ASD exhibited slightly degraded performance levels. The observed temporally selective enhancement in speed discrimination indicates that a local processing advantage in autism develops over a longer temporal range and is not limited to the spatial domain. These results suggest a dynamic perceptual mechanism for understanding, and therapeutically addressing, atypical visual processing in this neurodevelopmental disorder.
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Affiliation(s)
- Y Chen
- McLean Hospital, Department of Psychiatry, Harvard Medical School, United States.
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Atypical lateral connectivity: a neural basis for altered visuospatial processing in autism. Biol Psychiatry 2011; 70:806-11. [PMID: 21907325 DOI: 10.1016/j.biopsych.2011.07.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 06/29/2011] [Accepted: 07/20/2011] [Indexed: 11/23/2022]
Abstract
BACKGROUND Autistic perception encompasses both inferior and superior performance on different types of visuospatial tasks. Influential neurocognitive models relevant to atypical perception (i.e., weak central coherence, enhanced perceptual functioning) can, to differing degrees, account for these findings. However, the neural underpinnings mediating atypical visuospatial autistic perception have yet to be elucidated. METHODS In the present study, we used a lateral masking paradigm to assess the functional integrity of lateral interactions mediating visuospatial information processing within early visual areas of autistic (n = 18) and nonautistic (n = 15) observers. Detection thresholds were measured for centrally presented Gabor targets flanked collinearly at different distances (experiment 1) and flanked orthogonally at different contrasts (experiment 2). RESULTS Autistic and nonautistic groups showed increased target sensitivity when the distance between collinear targets and flankers was small (3 lambda) but not large (6 lambda). However, the effect of small-distance facilitation was significantly greater for the autistic group. In addition, we observed a group-specific effect of contrast: in the autistic group, target sensitivity was enhanced by low flanker contrasts of both 5% and 10% luminance difference, whereas for the nonautistic group, this effect occurred at 10% contrast only. CONCLUSIONS These findings support the idea that atypical visuospatial perception in autism may originate from altered lateral connectivity within primary visual areas, differentially affecting perception at the earliest levels of feature extraction.
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15
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Bertone A, Hanck J, Kogan C, Chaudhuri A, Cornish K. Using perceptual signatures to define and dissociate condition-specific neural etiology: autism and fragile X syndrome as model conditions. J Autism Dev Disord 2011; 40:1531-40. [PMID: 20886276 DOI: 10.1007/s10803-010-1109-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The functional link between genetic alteration and behavioral end-state is rarely straightforward and never linear. Cases where neurodevelopmental conditions defined by a distinct genetic etiology share behavioral phenotypes are exemplary, as is the case for autism and Fragile X Syndrome (FXS). In this paper and its companion paper, we propose a method for assessing the functional link between genotype and neural alteration across these target conditions by comparing their perceptual signatures. In the present paper, we discuss how such signatures can be used to (1) define and differentiate various aspects of neural functioning in autism and FXS, and subsequently, (2) to infer candidate causal (genetic) mechanisms based on such signatures (see companion paper, this issue).
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Affiliation(s)
- Armando Bertone
- Perceptual Neuroscience Laboratory for Autism and Developmental Conditions, University of Montreal Center of Excellence for Pervasive Developmental Disorders (CETEDUM), Hôpital Rivière-des-Prairies, 7070 boulevard Perras, Montreal, Quebec, Canada.
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16
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Bertone A, Hanck J, Kogan C, Chaudhuri A, Cornish K. Associating neural alterations and genotype in autism and fragile x syndrome: incorporating perceptual phenotypes in causal modeling. J Autism Dev Disord 2011; 40:1541-8. [PMID: 20872060 DOI: 10.1007/s10803-010-1110-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We have previously described (see companion paper, this issue) the utility of using perceptual signatures for defining and dissociating condition-specific neural functioning underlying early visual processes in autism and FXS. These perceptually-driven hypotheses are based on differential performance evidenced only at the earliest stages of visual information processing, mediated by local neural network functioning. In this paper, we first review how most large-scale neural models are unable to address atypical low-level perceptual functioning in autism, and then suggest how condition-specific, local neural endophenotypes (described in our companion paper) can be incorporated into causal models to infer target candidate gene or gene clusters that are implicated in autism's pathogenesis. The usefulness of such a translational research approach is discussed.
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Affiliation(s)
- Armando Bertone
- Perceptual Neuroscience Laboratory for Autism and Developmental Conditions, University of Montreal Center of Excellence for Pervasive Developmental Disorders (CETEDUM), Hôpital Rivière-des-Prairies, 7070 boulevard Perras, Montreal, Quebec, Canada.
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17
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Atypical processing of auditory temporal complexity in autistics. Neuropsychologia 2011; 49:546-55. [DOI: 10.1016/j.neuropsychologia.2010.12.033] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 12/07/2010] [Accepted: 12/20/2010] [Indexed: 11/24/2022]
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A comparative psychophysical approach to visual perception in primates. Primates 2009; 50:121-30. [DOI: 10.1007/s10329-008-0128-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Accepted: 12/23/2008] [Indexed: 11/26/2022]
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