Schedule of Events | Symposia

Sketchpad Series

Investigating the role of human mediodorsal thalamus in odor-guided behavior

Poster Session F - Tuesday, April 1, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Jared Newell¹ (jarednewell@brandeis.edu), Lauren Wolters¹, James Howard¹; ¹Brandeis University

In order to perform critical functions like obtaining food, avoiding prey, and selecting mates, nervous systems must be able to transform olfactory sensation at the periphery into adaptive behaviors. One key region for coordinating this function is the mediodorsal thalamus (MDT), which is densely connected with both olfactory sensory cortex and prefrontal substrates. Recent animal studies demonstrate that MDT both encodes information about specific odorants, and mediates connectivity with sensory and prefrontal cortices to guide behavior. However, the mechanisms by which MDT supports odor-guided behavior in humans remain unknown. Here we designed an experiment in which human participants perform an odor-guided learning task while undergoing fMRI. On each trial of the task, participants receive one of three distinct odors and then make one of two possible responses to receive a monetary reward. Critically, in some trial blocks the rewarded response is the same regardless of odor identity, and in other blocks identity determines the correct response. This experimental design allows us to test the primary hypothesis that ensemble MDT activity preferentially encodes information about odor identity when identity is relevant for making a decision. Preliminary behavioral results (n=15) indicate that participants make highly accurate choices regardless of block type, and that residual differences in odor pleasantness and intensity do not affect performance. Planned analyses of fMRI data will employ multivariate pattern-based techniques to characterize how the balance of olfactory sensory and behavioral task variables are represented in olfactory sensory cortex, MDT, and prefrontal cortex to support learning.

Topic Area: PERCEPTION & ACTION: Other