The role of cortico-basal ganglia circuits in skill learning during development

技能学习，就像说话一样，包括基于实践的学习行为。 基础神经科学的一个基本问题是：学习者如何衡量学习的成功，或者大脑如何评估与目标相关的行为结果？ 例如，父母通过发出成熟的声音（目标）来充当声乐导师，人类婴儿在练习牙牙学语时必须学会再现这些声音。 技能学习被认为涉及自我产生的行为结果的目标导向的评估。孩子会评估自己的牙牙学语与父母成熟声音的匹配程度。这会逐渐塑造大脑回路，以选择适当的行动。 在这种情况下，当婴儿将自己的牙牙学语声音与父母发出的成熟目标声音进行比较时，他们逐渐学会模仿这些成熟的语音。鸣禽的发声学习为研究特定的神经回路如何在发育过程中介导这种依赖经验的技能学习提供了一个强有力的模型。 像人类婴儿一样，年轻的鸣禽参与了一个目标导向的过程，在这个过程中，根据从导师那里学到的目标声音的记忆来评估发声，从而指导逐渐习得发声行为。 与其他形式的技能学习一样，成功的习得需要神经回路将自我产生的行为反馈与目标表征进行比较。 这些研究将为神经回路如何调节技能学习创造新的知识。 这一新知识将用于帮助少数民族比例偏低地区的小学生制定课程计划，以及教师培训方案，以促进科学教育和扫盲。 本研究的目的是探讨皮质基底神经节通路内的特定亚回路是否介导目标导向技能学习的不同方面。 利用鸣禽的声音学习作为实验模型，研究人员将测试特定神经回路在评估动物改善运动输出时针对目标行为的自发行为中的作用。 幼年鸣禽学习行为目标（从导师那里记住的声音），并在试错学习过程中产生可变的行为输出（咿呀学语），在这个过程中，与学习到的目标声音相匹配的行为逐渐加强。 研究小组将记录幼鸟在发育过程中的神经活动，因为它们积极参与学习;我们的策略是从不同的神经元亚群中记录，这些神经元通过选择性调谐来识别目标的神经表征或自我生成行为的反馈，因为幼鸟开始完善它们的行为输出。 他们认为，这两种目标导向学习的神经信号产生了不同的子回路，作为行动结果评估机制的一部分。 一个主要的预测是，皮层神经元选择性地调谐到记忆的目标表征，提供了一个过滤器，用于识别与目标匹配的行为，并将此信息传递给基底神经节。 这些数据将提供一个重要的测试，如何识别和处理类似目标的行动在皮层电路及其下游targets.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Skill learning, like speaking, includes learning behaviors based on practice. A fundamental question of basic neuroscience is: how do learners measure success in learning, or how does the brain evaluate behavioral outcomes in relation to a goal? For example, parents serve as vocal tutors by uttering mature sounds (the goals) which human infants must learn to reproduce as they practice babbling. Skill learning is thought to involve goal-directed evaluation of self-generated behavioral outcomes. The child evaluates how closely their babbling matches their parents’ mature sounds. This gradually shapes brain circuits to select appropriate actions. In this case, as infants compare their own babbling sounds to the mature goal sounds made by parents, they gradually learn to emulate those mature speech sounds. Vocal learning in songbirds provides a powerful model for studying how specific neural circuits mediate such experience-dependent skill learning during development. Like human infants, young songbirds engage in a goal-oriented process in which evaluation of vocal utterances against a memory of goal sounds learned from a tutor guides gradual acquisition of learned vocal behavior. As in other forms of skill learning, successful acquisition requires neural circuits to carry out comparisons of self-generated behavioral feedback to goal representations. These studies will create new knowledge of how neural circuits mediate skill learning. This new knowledge will be used to help in developing lesson plans for elementary-school students in areas with high proportions of under-represented minorities and training programs for teachers in order to advance science education and literacy. The objective of this research project is to investigate whether specific subcircuits within cortico-basal ganglia pathways mediate distinct aspects of goal-directed skill learning. Using vocal learning in songbirds as an experimental model, the investigators will test the role of specific neural circuits in evaluating self-generated actions against a goal behavior as animals refine their motor output. Juvenile songbirds learn a behavioral goal (memorized vocal sounds from a tutor) and produce variable behavioral output (babbling) during a process of trial-and-error learning in which actions that match the learned goal sounds are gradually strengthened. The research team will record neural activity in juvenile songbirds during development as they are actively engaged in learning; our strategy is to record from distinct subgroups of neurons identified by their selective tuning to either a neural representation of the goal or to feedback of self-generated behavior as juvenile birds begin to refine their behavioral output. They posit that these two neural signals of goal-directed learning give rise to distinct subcircuits as part of the mechanism underlying action-outcome evaluations. One major prediction is that cortical neurons that are selectively tuned to the memorized goal representation provide a filter for identifying behavior that matches the goal, and convey this information to the basal ganglia. These data will provide an important test of how goal-similar actions are identified and processed in cortical circuits and their downstream targets.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.