Abstract

If you have a question about this talk, please contact Elisa Galliano.

My lab studies the distributed mechanisms that support sensorimotor learning, with an emphasis on the role of neuromodulation and sensory systems. In this seminar, I will propose that re-visiting our understanding of the shape of the learning curve and its underlying cognitive drivers is essential for uncovering its neural basis. Rather than thinking about learning as either ‘slow’ or ‘sudden’, I will argue that learning is better interpreted as a combination of the two. I will provide behavioral evidence that sensorimotor learning can be dissociated into two parallel processes: rapid, step-like improvements in the acquisition of task knowledge, paired with a slower and more variable process of behavioral expression, which can be attributed to animals’ structured exploration. I will then present probabilistic optogenetic and longitudinal two-photon imaging results from mice learning an auditory go/no-go task that demonstrates a default role for the auditory cortex in task acquisition. We find dedicated neural ensembles that quickly form to encode the discriminative task contingencies; these late-in-trial contingency signals are uncoupled from the underlying stimulus representation. By employing closed-loop optogenetic inactivation, we observe that disrupting these post-cue contingency signals throughout learning impairs acquisition. Our work reveals that the sensory cortex does more than enhance the representation of behaviorally-relevant stimuli, it dynamically forms discriminative contingencies within discrete ensembles, spotlighting a pivotal associative role for the sensory cortex in sensorimotor learning.