Entry Date:
January 26, 2016

Advancing a Biomarker of Reduced GABAergic Neurotransmission in Autism

Principal Investigator Nancy Kanwisher

Individuals with autism report exceptionally quick and accurate perception of small details in the visual environment. Yet, this detailed perception is not always to an individual’s advantage: individuals with autism also report difficulty in “filtering out” redundant and conflicting sensory information, leading to a sensory experience which is often described as “overloaded”.

We have recently discovered a behavioral correlate of this hallmark autistic symptom: individuals with autism evidence strikingly weak perceptual inhibition of conflicting information during binocular rivalry (Robertson et al., 2013), a simple perceptual task which can be used to test the strength of inhibition between populations of neurons with opposite selectivity in visual cortex.

We now seek to establish the neurobiological origins of this effect using a combination of highresolution magnetic resonance spectroscopy (MRS), functional imaging methods (fMRI and EEG), and behavioral techniques. Critically, we aim to link these fundamental perturbations in autistic visual behavior to a prominent hypothesis of autistic neural circuitry: that concentration of a particular neurotransmitter, GABA, may be reduced in the autistic cortex.