Marked selective impairment in autism on an index of magnocellular function
| Autor: | Greg Davis, Kate Plaisted-Grant, Rebecca Greenaway |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Male
Visual perception Adolescent genetic structures Cognitive Neuroscience media_common.quotation_subject Experimental and Cognitive Psychology Adaptation (eye) Fixation Ocular Lateral geniculate nucleus Contrast Sensitivity Behavioral Neuroscience Discrimination Psychological Parvocellular cell Neural Pathways medicine Humans Contrast (vision) Visual Pathways Asperger Syndrome Autistic Disorder Child Lighting media_common medicine.disease Asperger syndrome Basal Nucleus of Meynert Fixation (visual) Visual Perception Autism Female Psychology Neuroscience Photic Stimulation Psychomotor Performance Software Cognitive psychology |
| Zdroj: | Neuropsychologia. 51:592-600 |
| ISSN: | 0028-3932 |
| DOI: | 10.1016/j.neuropsychologia.2013.01.005 |
| Popis: | Atypical high-level vision in autism is sometimes attributed to a core deficit in the function of lateral geniculate nucleus magnocells or their retinal drives. While some physiological measures provide indirect, suggestive evidence for such a deficit, support from behavioural measures is lacking and contradictory. We assessed luminance contrast increment thresholds on pulsed- and steady- pedestals in 17 children with autism spectrum conditions (ASC) compared to 17 typically developing children; these two conditions correspond to widely-used indices of magnocellular and parvocellular function. As a group, children with ASC had strikingly elevated thresholds on the steady pedestal-paradigm, yet performed similarly to controls on the pulsed pedestal paradigm, a finding that would typically be interpreted to reflect impaired magnocellular function. The effect size of the impairment was large and a substantial minority (41.2%) of the ASC group showed significantly impaired performance on an individual basis. This finding is consistent with a selective magnocellular deficit. It directly contradicts previous claims that such deficits are confined to 'complex' visual stimuli and likely does not reflect atypical attention, adaptation or high-level vision. The pattern of results is not clearly predicted by notions of imbalance of excitation versus inhibition, atypical lateral connectivity or enhanced perceptual function that account for a range of other findings associated with perception in autism. It may be amenable to explanation in terms of decreased endogenous neural noise, a novel alternative we outline here. |
| Databáze: | OpenAIRE |
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