Inadequate cortical feature maps: a neural circuit theory of autism

Abstract

The autistic syndromes are caused by neurological dysfunctions. The capacity of autistic individuals to form representations of previous sensory impressions, useful for the processing of present information, is impaired. Self-organizing feature maps are mathematical models of cortical feature maps and may be used to simulate cortical processing. Dysfunctional self-organization, resulting in disability to extract features from stimuli, is proposed as a neural circuit theory of autism. The nature and a possible cause of dysfunction self-organization are examined. It is shown that impaired feature detection is valid for explaining the memory function in autism, the lack of drive for central coherence according to Frith's theory of autism, and a number of impairments from the diagnostic criteria. Unequal levels of impairment of different cortical feature maps can account for the typically uneven intelligence profile of autistic individuals. Excessive inhibitory lateral feedback synaptic connection strengths are presented as one factor impairing the development of feature maps. Strong or excessive inhibitory lateral feedback synaptic connection strengths also cause high sensory discrimination and abnormal sensory responses, both documented in autism. A neural circuit theory for autism has been presented. For a proof of this neural circuit theory neurological investigations are required.