Identifying an Error Detection Circuit used for Internally Guided Learning

文摘:

Abstract: Certain behaviors, including speech, are learned without external punishment or reward. Although the neural circuits responsible for such internally guided learning remain poorly understood, they must include a circuit that evaluates performance with reference to an internal model and transmits the resulting error signals to downstream circuitry that adaptively reinforces behavior. The objective of this proposal is to identify evaluative circuits that generate and transmit error signals important to internally guided vocal learning in songbirds. The specific circuit node that will be studied is an auditory cortical homologue that provides direct input to midbrain dopamine neurons that have recently been shown to adaptively reinforce vocal performance. I hypothesize that this same pathway will be an essential player in the circuits of two discrete examples of internally evaluated behavior: juvenile copying of a memorized tutor song and adult recovery of original song structure following chronic exposure to distorted auditory feedback. I will test this hypothesis using causal, closed loop optogenetic manipulations and correlative, widefield calcium imaging experiments. The completion of the aims in this proposal will shed light on the neural circuits that mediate the self-evaluation necessary for a form of internally guided vocal learning that shares parallels to human speech learning.