Atypical sensory perception occurs in up to 90 per cent of autistic people—despite this, the dominant view of autism as primarily a “social” condition.
This has led to sensory symptoms being largely overlooked, particularly in neuroimaging research.
As a start, PhD researcher Nazia Jassim and colleagues decided to meta-analyse the non-social sensory perception task fMRI literature published to date. A comprehensive literature search and stringent inclusion criteria identified 83 experiments from 52 studies comparing 891 autistic and 967 typical participants.
To quantify differences across a wide range of perceptual processing tasks, they first meta-analysed non-social fMRI tasks covering the various steps involved in perception. Control groups, when compared to autistic groups, showed consistently greater prefrontal activity.
Next, they categorized studies according to sensory modality and conducted more refined analyses on classic visual processing paradigms.
Autistic groups recruited the extrastriate Area V2 to a greater extent than controls across visual processing studies.
They also explored brain regions of differential activity during auditory & tactile processing. Further details of these preliminary analyses can be found in the paper.
Taken together, the keys findings add to current theories of autistic sensory perception, notably in the visual domain. At the same time, they highlight the lack of consistent neuroimaging findings in autism due to its heterogeneity.
Nazia Jassim is a PhD researcher she uses a variety of cognitive neuroscience techniques, from behavioural experiments to ultra-high-resolution 7T neuroimaging, to investigate sensory perception and brain function in Autism Spectrum Conditions. Based at the Autism Research Centre of the Department of Psychiatry and she also works with the Prediction and Learning Lab.