RLDM Conference 2025 Conference Abstract
RLDM 2025 Abstract Booklet 158 The role of the thalamus in dynamic decision-making Caldinelli, C. ∗ Li, J. -J. Arcaro, M. J. Helen Wills Neuroscience Department Helen Wills Neuroscience Department Department of Psychology
- Caldinelli
- C. ∗ Li
- J. -J. Arcaro
- M. J.
- CA 94720 Berkeley
- CA 94720 Philadelphia
- PA 19104
- Collins
Booklet 158 The role of the thalamus in dynamic decision-making Caldinelli, C. ∗ Li, J. -J. Arcaro, M. J. Helen Wills Neuroscience Department Helen Wills Neuroscience Department Department of Psychology University of California, Berkeley University of California, Berkeley University of Pennsylvania Berkeley, CA 94720 Berkeley, CA 94720 Philadelphia, PA 19104 chiarac@berkeley. edu Collins, A. G. E Department of Psychology and Helen Wills Neuroscience Department University of California, Berkeley Berkeley, CA 94720 Abstract The thalamus lies in a pivotal position as an integrative hub for areas involved in high-level cognition. Despite its important theoretical role in many computational models and its involvement in psychiatric disorders, the human thalamus has not been studied much in the context of higher level cognition and cognitive flexibility. However, studies with non-human animals show involvement of the mediodorsal nucleus (MD) and the prefrontal cortex [1] during rule representation and switching, and a dysfunction of hub regions is associated with behavioral and cognitive impairment [2], [3]. We developed a novel behavioral task inspired by a previous rule switching task [4], [5] to probe rapid rule switching under uncertainty. Behavioral and computational modeling results show that during this task participants integrate reward uncertainty together with higher order task structure knowledge to efficiently explore the rule space. We use an extension of the PROBE model [5] to identify discrete transitions between periods of rule exploration and exploitation. 42 participants underwent an fMRI session performing a total the task. Preliminary results show an activation of the mediodorsal nucleus (MD) and the prefrontal cortex (PFC) during switch trials and rule exploration periods. Further analysis will confirm the association of MD with preferential coding of frequent rules. If the thalamus shows to be involved in a rule switching task, it would suggest a primary role in enabling the integration of information in dynamically changing and ambiguous environments such as solving a problem in the presence of uncertainty and updating the rules required to achieve a goal thanks to the extensive and reciprocal connections between the frontal and parietal cortices.