More than 70 years after Leo Kanner first described autism as a behavioural pattern affecting mainly children, research on this spectrum of complex conditions is still leading us to more questions than answers. A recent study published in the journal Cerebral Cortex might be taking us back to square one: its evidence suggests that a previously widely accepted theory regarding the neural responses specific to autism spectrum disorders might actually be false.
Autism is a widely researched yet still poorly understood spectrum of neurodevelopmental disorders, characterised by impaired communication and social interaction, as well as atypical behaviour and responses to stimuli, such as repeating certain actions. One proposed cause for these altered neural processes has been the so-called “neural unreliability” of those affected by autism spectrum disorders. The neural unreliability theory, which has emerged over the past few years, suggests that the brain normally responds to repetitive visual, audio or tactile stimuli in a consistent way and that this response is more variable in the brains of autistic people, which eventually translates into abnormal cognitive patterns.
However, the study that initially brought this theory forward used a neuroimaging method which has since been deemed unsatisfactory for assessing such rapid brain processes. As a result, for this new study scientists from the University of Rochester decided to make use of more detailed high-density electrical mapping in order to more accurately assess the differences in neural response between 20 individuals with autism and 20 control patients. Surprisingly, they found no significant differences between the two groups, which suggests that the response of the autistic brain to repetitive stimuli is just as reliable and predictable as that of the controls.
These findings are welcome in the field of autism research, as unsubstantiated theories are always best dismissed early on, and are also supported by a large body of evidence similarly suggesting that the sensory thresholds of individuals with autistic spectrum disorders are similar to those of control patients. However, the study opens up a whole new blank canvas for scientists working in a field that has seen several theories thrown out and very little progress made considering the percentage of the population that is affected by autism. As with every other field, more funding and research will be crucial if we are to untangle the mechanisms of this disorder.
This article was written by Teodora Aldea and edited by Hans-Joachim Sonntag.