hide
Free keywords:
-
Abstract:
The International Brain Laboratory (IBL) is a collaboration of several experimental and theoretical laboratories studying decision-making. Demonstrating robust, replicable, behavioral and electrophysiological data, with a growing complement of computational models, IBL provides an unparalleled opportunity to study the activity and function of neuromodulators, important in understanding learning and decision-making. We use fiber-photometry to record activity from genetically-defined neural populations in key nuclei of different neuromodulators. To acclimatize to the rig and head-fixation, mice start passively observing a visual stimulus followed by a water-reward delivery. We observe that both dopamine (DA) and serotonin (5-HT) respond to the unexpected water. Next, mice must learn to move the stimulus to the center by using a wheel. A divergence in DA signal is observed: activity increases upon water-reward and decreases upon noise burst (wrong decision), signaling a reinforcement prediction error, consistent with previous studies, at least under some circumstances and to some target nuclei. However, 5-HT increases to both reward and noise, suggesting an unsigned or state prediction error signal, related to results showing its role in learning modulation based on confidence or uncertainty. With the goal of recording the activity of the four primary neuromodulators in the same task, we are also acquiring data on norepinephrine and acetylcholine, which have various influences over decision-making, arousal and attention, and also interact with other neuromodulators. In combination with neurophysiological and neuroimaging data of cell activity in the IBL task, this study provides an unprecedented opportunity to investigate the role of neuromodulators in learning and decision-making.
