Biology subjects

Kozunova, G.

Publications and source records attributed to Kozunova, G..

3 recordsLinked to original sources

bioRxiv2025

ABERRANT NEURAL ADAPTATION TO EXPECTED UNCERTAINTY IN ADULTS WITH AUTISM SPECTRUM DISORDER

The ability to adjust brain resources to manage expected uncertainty is hypothesized to be impaired in autism spectrum disorder (ASD), though the evidence remains limited. To investigate this, we studied 29 neurotypical (NT) and 29 high-functioning adults with ASD performing a probabilistic two-alternative value-based task while undergoing magnetoencephalography (MEG) and pupillometry. The task comprised five sequential blocks with stable reward probabilities (70%:30%), but varying stimulus pairs and reward values, enabling assessment of behavioral and neural adaptation to expected uncertainty. We analyzed a hit rate of advantageous choices, response times, and computational measures of prior belief strength and precision. To examine cortical activation during decision-making, we used MEG source reconstruction to quantify -{beta} oscillation suppression in decision-relevant cortical regions within the pre-decision time window. Linear mixed models assessed trial-by-trial effects. Behaviorally, ASD participants exhibited lower overall belief precision but intact probabilistic rule generalization, showing gradual performance improvement and strengthening of prior beliefs across blocks. However, unlike NT individuals, they did not show progressive downscaling of neural activation during decision-making or reduction in neural response to feedback signals as performance improved. Furthermore, on a trial-by-trial basis, increased belief precision in ASD was not associated with reduced cortical activation, a pattern observed in NT individuals. These findings suggest an atypically rigid and enhanced allocation of neural resources to advantageous decisions in individuals with ASD - although they, as NT individuals, rationally judge such decisions as optimal. This pattern may reflect an aversive response to the irreducible uncertainty inherent in probabilistic decision-making.

neuroscience↗

bioRxiv2024

Atypical Pupil-Linked Arousal Induced by Low-Risk Probabilistic Choices, and Intolerance of Uncertainty in Adults with ASD

Adults with autism spectrum disorder (ASD) report stress when acting in a familiar probabilistic environment, but the underlying mechanisms are unclear. Their decision-making may be affected by the uncertainty aversion implicated in ASD, and associated with increased autonomic arousal. Previous studies have shown that in neurotypical (NT) people, decisions with predictably better outcomes are less stressful and elicit smaller pupil-linked arousal than those involving random "trial-and-error" searches or self-imposed risk of exploration. Here, in a sample of 46 high-functioning ASD and NT participants, we explored pupil-linked arousal and behavioral performance in a probabilistic reward learning task with a stable advantage of one choice option over the other. Using mixed-effects model analysis, we contrasted pupil dilation response (PDR) between a preferred frequently rewarded exploitative decision and its explorative alternatives. We observed that subjects with ASD learned the advantageous probabilistic choices at the same rate over time and preferred them to the same degree as NT participants both in terms of choice ratio and decision speed. Despite similar reward prediction abilities, outcome predictability modulated decision-related PDR in ASD in the opposite direction than in NT individuals. Moreover, relatively enhanced PDR elicited by exploitative low-risk decisions predicted a greater degree of self-reported intolerance of uncertainty in everyday life. Our results suggest that in a non-volatile probabilistic environment, objectively good predictive abilities in people with ASD are coupled with elevated physiological stress and subjective uncertainty regarding the decisions with the best possible but still uncertain outcome that contributes to their intolerance of uncertainty.

neuroscience↗

bioRxiv2021

Pupil Dilation and Response Slowing Distinguish Deliberate Explorative Choices in the Probabilistic Learning Task

This study examined whether pupil size and response time would distinguish directed exploration from random exploration and exploitation. Eighty-nine participants performed the two-choice probabilistic learning task while their pupil size and response time were continuously recorded. Using LMM analysis, we estimated differences in the pupil size and response time between the advantageous and disadvantageous choices as a function of learning success, i.e., whether or not a participant has learned the probabilistic contingency between choices and their outcomes. We proposed that before a true value of each choice became known to a decision-maker, both advantageous and disadvantageous choices represented a random exploration of the two options with an equally uncertain outcome, whereas the same choices after learning manifested exploitation and direct exploration strategies, respectively. We found that disadvantageous choices were associated with increases both in response time and pupil size, but only after the participants had learned the choice-reward contingencies. For the pupil size, this effect was strongly amplified for those disadvantageous choices that immediately followed gains as compared to losses in the preceding choice. Pupil size modulations were evident during the behavioral choice rather than during the pretrial baseline. These findings suggest that occasional disadvantageous choices, which violate the acquired internal utility model, represent directed exploration. This exploratory strategy shifts choice priorities in favor of information seeking and its autonomic and behavioral concomitants are mainly driven by the conflict between the behavioral plan of the intended exploratory choice and its strong alternative, which has already proven to be more rewarding.

neuroscience↗