Priors Bias Perceptual Decisions in Autism, But Are Less Flexibly Adjusted to the Context.
Autistic adults form expectations but don't tweak them when the situation changes — a possible driver of 'intolerance of uncertainty'.
01Research in Context
What this study did
Sapey-Triomphe et al. (2021) asked autistic and neurotypical adults to judge blurry pictures. The pictures changed how often they showed the same object. Sometimes the same object appeared 80% of the time. Sometimes only 20%.
The team tracked how fast each group updated their expectations when the odds flipped.
What they found
Both groups quickly learned the first pattern. But when the odds switched, autistic adults kept using the old rule. They did not tighten or loosen their expectations to match the new context.
The result: more wrong calls when the world changed.
How this fits with other research
Binur et al. (2022) ran a different lab game and saw the same thing. Autistic adults gave too much weight to old info and too little to new sensory cues. The two studies back each other up.
Król et al. (2019) tracked eye movements and found autistic viewers took longer to spot new patterns in pictures. The 2021 paper pins down why: the problem is not learning the first rule, it is shifting the rule when the scene changes.
South et al. (2012) showed kids with autism needed extra trials to flip a learned threat response. The adult data now show the stuck-prior issue lasts across the lifespan.
Why it matters
Your client may look 'stubborn' when rules change, but the data say their brain is stuck on the last reliable pattern. Give them a clear new cue ('the picture set is now 20% cats') and extra practice trials. Write the rule on a card. Rehearse the switch before the real task starts. These small steps can cut errors and lower anxiety when routines must change.
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02At a glance
03Original abstract
According to the predictive coding framework, percepts emerge from combinations of sensory input and prior knowledge, whose relative contributions depend on their reliability. Recent predictive coding theories suggest that Autism Spectrum Disorder (ASD) could be characterized by an atypical weighting of priors. Here, we assessed whether individuals with ASD can flexibly adjust the weight (precision) of the prior to the context. Thirty-one neurotypical adults (NT) and 26 adults with ASD participated in a visual discrimination task designed to elicit a time-order effect (TOE). The TOE reflects the integration of priors with sensory estimates. We used two experimental contexts: a narrow stimulus range (Narrow condition) and a broader range (Broad condition) in order to induce a prior with a higher and lower precision, respectively. Both groups learned a prior that biased their perception, as shown with the TOE. As expected, the NT group had a larger TOE in the Narrow condition than in the Broad condition, revealing a contextual adjustment of the prior precision. In contrast, ASD participants were more inflexible: the extent of the TOE was not modulated by the context. In addition, the accuracy increased when the stimulus range decreased in both group, which may be interpreted as a contextual adjustment of the sensory precision. To conclude, adults with and without ASD implicitly learned a prior mean, but ASD participants failed to flexibly adjust the prior precision to the context. This increased inflexibility in ASD could account for many symptoms, such as their intolerance of uncertainty. LAY SUMMARY: Based on our experience, we have expectations about our environment. Theories suggest that the symptoms encountered in autism could be due to atypical expectations, leading to an impression of an unpredictable world. Using a visual discrimination task, we showed that adults with and without autism were biased by their expectations. Yet, the extent to which expectations biased perception did not depend on the context in autism. This higher inflexibility found in autism may explain symptoms such as resistance to change.
Autism research : official journal of the International Society for Autism Research, 2021 · doi:10.1002/aur.2452