Autism is currently identified by a set of diagnostic criteria which are based on observable behaviour, denoting a pattern of impairments in communication and social reciprocity, and a tendency for restricted and stereotyped patterns of behaviour and interests. During the past eighteen years, biographical accounts have enriched the conventional autism literature and provided insights into the experience of autism that may inform both research and practice. This paper presents a synthesis of two themes reported frequently in first-hand accounts: difficulties in sensory processing and social perception. Viewed in conjunction with selected research evidence, a picture emerges of underlying basic deficits that may underpin the observable behaviours of the current diagnostic criteria. It is hoped that the article will be of assistance to practitioners in developing an understanding of the nature of autism spectrum disorders.