People with autism are less surprised by the unexpected

Individuals with autism spectrum disorders (ASD) may overestimate the volatility of the world around them, a new study suggests. 

Rebecca Lawson and colleagues enrolled 24 adults with ASD and 25 neurotypical adults in their study. Participants completed a task that involved learning to anticipate certain pictures appearing on a computer screen after hearing either a high or low sound. 

The adults with autism performed the task successfully overall. However, they overestimated the volatility of the task, and thus were less able to form expectations about upcoming pictures. The more severe the symptoms of participants with ASD were, the less surprised they were by an unexpected picture. 

Lawson comments, “When we’re uncertain about our own beliefs, such as under volatile conditions, we’re driven more by our senses than our prior expectations. If people with autism are more often expecting volatility, that could help explain their propensity to sensory overload, enhanced perceptual functioning and context insensitivity.” She adds that the research “represents an important advance in our understanding of how people with autism see the world differently.” 

The researchers also found that measures of learning and surprise were associated with changes in pupil size. These changes, they say, are believed to reflect the function of neuromodulating brain chemicals such as noradrenaline. 

Citations

“Adults with autism overestimate the volatility of the sensory environment,” Rebecca P. Lawson, Christoph Mathys, and Geraint Rees, Nature Neuroscience, July 31, 2017 (online). Address: Rebecca P. Lawson, Wellcome Trust Centre for Neuroimaging, 12 Queen Square, London WC1N 3BG, [email protected]. 

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“People with autism are less surprised by the unexpected,” news release, University College London, July 31, 2017.