Sub-second dopamine and serotonin signalling in human striatum during perceptual decision-making

Links for joining will be sent out before each seminar. Please contact the organisers to be added to the list of attendees.

Recent animal research indicates that dopamine and serotonin, neuromodulators traditionally associated with appetitive and aversive processes, are also involved in sensory inference and decisions based on such inference. In this talk, I will present a study in which we tested this hypothesis in the human brain. We used fast-scan cyclic voltammetry adapted for use during DBS surgery to monitor sub-second changes in striatal dopamine and serotonin while patients performed a visual perceptual decision task that separates sensory uncertainty from decision difficulty in a factorial design. Caudate nucleus recordings (n=4) revealed multi-scale encoding: in three patients, serotonin tracked sensory uncertainty, and, in one patient, both dopamine and serotonin tracked deviations from expected trial transitions within our factorial design. Putamen recordings (n=1) supported a cognition-action separation between caudate nucleus and putamen – a striatal sub-division unique to primates – with both dopamine and serotonin tracking decision times. I will argue that these first-of-their-kind observations in the human brain support a role for sub-second dopamine and serotonin signalling in non-reward-based aspects of cognition and action.