Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
Curr Biol. 2022 Nov 21;32(22):4925-4940.e6. doi: 10.1016/j.cub.2022.09.064. Epub 2022 Oct 24.
Many of the sensations experienced by an organism are caused by their own actions, and accurately anticipating both the sensory features and timing of self-generated stimuli is crucial to a variety of behaviors. In the auditory cortex, neural responses to self-generated sounds exhibit frequency-specific suppression, suggesting that movement-based predictions may be implemented early in sensory processing. However, it remains unknown whether this modulation results from a behaviorally specific and temporally precise prediction, nor is it known whether corresponding expectation signals are present locally in the auditory cortex. To address these questions, we trained mice to expect the precise acoustic outcome of a forelimb movement using a closed-loop sound-generating lever. Dense neuronal recordings in the auditory cortex revealed suppression of responses to self-generated sounds that was specific to the expected acoustic features, to a precise position within the movement, and to the movement that was coupled to sound during training. Prediction-based suppression was concentrated in L2/3 and L5, where deviations from expectation also recruited a population of prediction-error neurons that was otherwise unresponsive. Recording in the absence of sound revealed abundant movement signals in deep layers that were biased toward neurons tuned to the expected sound, as well as expectation signals that were present throughout the cortex and peaked at the time of expected auditory feedback. Together, these findings identify distinct populations of auditory cortical neurons with movement, expectation, and error signals consistent with a learned internal model linking an action to its specific acoustic outcome.
许多生物体所经历的感觉是由它们自己的行为引起的,准确地预测自我产生刺激的感觉特征和时间对于各种行为至关重要。在听觉皮层中,对自我产生声音的神经反应表现出频率特异性抑制,这表明基于运动的预测可能在感觉处理的早期就被实施了。然而,目前尚不清楚这种调制是否是由行为特异性和时间精确性预测引起的,也不知道在听觉皮层中是否存在相应的预期信号。为了解决这些问题,我们训练老鼠使用闭环发声杆来预期前肢运动的确切声学结果。在听觉皮层中进行的密集神经元记录显示,对自我产生声音的反应受到抑制,这种抑制特异性地针对预期的声学特征、运动中的精确位置以及在训练过程中与声音相关的运动。基于预测的抑制集中在 L2/3 和 L5 层,其中与预期的偏差也会招募一群预测误差神经元,而这些神经元在其他情况下是没有反应的。在没有声音的情况下进行记录,发现深层有大量偏向于预期声音的神经元的运动信号,以及在整个皮层中存在的、在预期听觉反馈时达到峰值的预期信号。这些发现共同确定了具有运动、预期和误差信号的听觉皮层神经元的不同群体,这些信号与将动作与其特定的声学结果联系起来的学习内部模型一致。