Biology subjects

Solopchuk, O.

Publications and source records attributed to Solopchuk, O..

4 recordsLinked to original sources

bioRxiv2025

BELIEFS: A Hierarchical Theory of Mind Model based on StrategyInference

Theory of Mind (ToM) refers to the ability to infer another agents latent mental states, such as intentions, beliefs, and strategies, to predict their behavior. A core feature of ToM is its recursive structure: individuals reason not only about what others think, but also about what others think about them. Existing computational models typically assume that ToM Level-0 (L0) agents rely on a fixed heuristic (e.g., Win-Stay Lose-Shift, WSLS), an assumption that fails to capture the diversity of non-mentalizing strategies humans actually use. Here we introduce BELIEFS, a probabilistic ToM framework that infers latent L0 strategies directly from behavior using a Hidden Markov Model (HMM) that enables flexible tracking of elemental strategies and dynamic switches between them without relying on a single predefined heuristics. A second HMM tracks the beliefs about the Opponents ToM level and dynamic changes therein. We evaluated BELIEFS across four classic dyadic games (Matching Pennies, Prisoners Dilemma, Bach or Stravinsky, Stag Hunt) under varying learning rates and volatility of strategy switches. Predictive performance, quantified via cumulative negative log-likelihood (NLL) of the opponents choices, was compared against chance and a WSLS-based ToM model, with BELIEFS consistently achieving superior accuracy across conditions. Strategy inference was assessed using trial-wise confusion matrices and Cohens {kappa}, revealing robust above-chance classification. Additionally, separability of ToM levels across games indicated that competitive games are particularly informative for distinguishing recursive reasoning from deterministic L0 strategies. The model also successfully tracked the opponents recursive reasoning depth (i.e. ToM level) by distinguishing action sequences generated by L0 versus L1 opponents. Parameter-recovery analyses confirmed reliable estimation of core transition parameters. Together, these results show that BELIEFS provides a flexible, computationally grounded account of human ToM, jointly inferring surface-level strategies and recursive reasoning, with applications to modeling adaptive behavior in dynamic interactive environments.

neuroscience↗

bioRxiv2024

Multifaceted confidence in exploratory choice

Our choices are typically accompanied by a feeling of confidence - an internal estimate that they are correct. Correctness, however, depends on our goals. For example, exploration-exploitation problems entail a tension between short- and long-term goals: finding out about the value of one option could mean foregoing another option that is apparently more rewarding. Here, we hypothesised that after making an exploratory choice that involves sacrificing an immediate gain, subjects will be confident that they chose a better option for long-term rewards, but not confident that it was a better option for immediate reward. We asked 250 subjects across 2 experiments to perform a varying-horizon two-arm bandits task, in which we asked them to rate their confidence that their choice would lead to more immediate, or more total reward. Confirming previous studies, we found a significant increase in exploration with increasing trial horizon, but, contrary to our predictions, we found no difference between confidence in immediate or total reward. This dissociation is further evidence for a separation in the mechanisms involved in choices and confidence judgements.

neuroscience↗

bioRxiv2017

An information-theoretic perspective on the costs of cognition

In statistics and machine learning, model accuracy is traded off with complexity, which can be viewed as the amount of information extracted from the data. Here, we discuss how cognitive costs can be expressed in terms of similar information costs, i.e. as a function of the amount of information required to update a persons prior knowledge (or internal model) to effectively solve a task. We then examine the theoretical consequences that ensue from this assumption. This framework naturally explains why some tasks - for example, unfamiliar or dual tasks - are costly and permits to quantify these costs using information-theoretic measures. Finally, we discuss brain implementation of this principle and show that subjective cognitive costs can originate either from local or global capacity limitations on information processing or from increased rate of metabolic alterations. These views shed light on the potential adaptive value of cost-avoidance mechanisms.

neuroscience↗

bioRxiv2017

Objective but not subjective fatigue increases cognitive task avoidance

Mentally demanding tasks feel effortful and are usually avoided. Furthermore, prolonged cognitive engagement leads to mental fatigue, consisting of subjective feeling of exhaustion and decline in performance. Despite the intuitive characterization of fatigue as an increase in subjective effort perception, the effect of fatigue on effort cost has never been tested experimentally. To this end, sixty participants in 2 separate experiments underwent a forced-choice working memory task following either a fatigue-inducing (i.e. Stroop task) or a control manipulation. We measured subjective fatigue and effort as well as their objective behavioral signatures: performance decline and task avoidance, respectively. We found that fatigue-induced performance decline was correlated with task avoidance, while the feelings of fatigue and effort were unrelated to each other. Our findings highlight the discrepancy between subjective and objective manifestations of fatigue and effort, and provide valuable evidence feeding the ongoing theoretical debate on the nature of these constructs.

neuroscience↗