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.
Complex skills such as speech and musical performance are learned without external reinforcers and are instead learned via an internally guided process. While many studies have helped elucidate the neural circuits that enable learning of externally reinforced behavior, the circuits that drive such forms of ?internally guided? learning still remain unknown. This proposal aims to use the circuit manipulations in the zebra finch in order to establish a causal link between putative error detecting cells and internally guided forms of learning.
