Autistic brains focus more on visual skills: Study

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Autistic brains focus more on visual skills: Study

Published: Tuesday, Apr 5, 2011, 20:29 IST

Washington, DC

People with autism concentrate more brain resources in the areas associated

with visual detection and identification, and conversely, have less activity in

the areas used to plan and control thoughts and actions, according to a new

study.

Researchers, led by t Mottron at the University of Montreal, said that the

findings might explain why these people have exceptional visual abilities.

Aiming to understand why autistic individuals have strong abilities in terms of

processing visual information, the researchers collated 15 years of data that

covered the ways autistic brain works when interpreting faces, objects and

written words.

The data came from 26 independent brain-imaging studies that looked at a total

of 357 autistic and 370 non-autistic individuals.

" Through this meta-analysis, we were able to observe that autistics exhibit more

activity in the temporal and occipital regions and less activity in frontal

cortex than non-autistics. The identified temporal and occipital regions are

typically involved in perceiving and recognizing patterns and objects. The

reported frontal areas subserve higher cognitive functions such as

decision-making, cognitive control, planning and execution, " said first author

Fabienne Samson.

" This stronger engagement of the visual processing brain areas in autism is

consistent with the well documented enhanced visuo-spatial abilities in this

population, " he added.

The current findings suggested a general functional reorganization of the brain

in favor of perception processes, the processes by which information is recorded

the brain.

This allows autistic individuals to successfully perform, albeit in their own

way, higher-level cognitive tasks that would usually require a strong

involvement of frontal areas in typical individuals.

These are tasks that require reasoning, for example, a research participant

would be asked if a statement is true or false, or to categorize a range of

objects into groups.

" We synthesised the results of neuroimaging studies using visual stimuli from

across the world. The results are strong enough to remain true despite the

variability between the research designs, samples and tasks, making the

perceptual account of autistic cognition currently the most validated model, "

Mottron said.

" The stronger engagement of the visual system, whatever the task, represents the

first physiological confirmation that enhanced perceptual processing is a core

feature of neural organization in this population. We now have a very strong

statement about autism functioning which may be ground for cognitive accounts of

autistic perception, learning, memory and reasoning. "

This finding shows that the autistic brain successfully adapt by reallocating

brain areas to visual perception, and offers many new lines of enquiry with

regards to developmental brain plasticity and visual expertise in autistics.

The findings appear in Human Brain Mapping.