Audette Nicholas J, Schneider David M
Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
bioRxiv. 2023 May 1:2023.01.06.523032. doi: 10.1101/2023.01.06.523032.
Comparing expectation with experience is an important neural computation performed throughout the brain and is a hallmark of predictive processing. Experiments that alter the sensory outcome of an animal's behavior reveal enhanced neural responses to unexpected self-generated stimuli, indicating that populations of neurons in sensory cortex may reflect prediction errors - mismatches between expectation and experience. However, enhanced neural responses to self-generated stimuli could also arise through non-predictive mechanisms, such as the movement-based facilitation of a neuron's inherent sound responses. If sensory prediction error neurons exist in sensory cortex, it is unknown whether they manifest as general error responses, or respond with specificity to errors in distinct stimulus dimensions. To answer these questions, we trained mice to expect the outcome of a simple sound-generating behavior and recorded auditory cortex activity as mice heard either the expected sound or sounds that deviated from expectation in one of multiple distinct dimensions. Our data reveal that the auditory cortex learns to suppress responses to self-generated sounds along multiple acoustic dimensions simultaneously. We identify a distinct population of auditory cortex neurons that are not responsive to passive sounds or to the expected sound but that explicitly encode prediction errors. These prediction error neurons are abundant only in animals with a learned motor-sensory expectation, and encode one or two specific violations rather than a generic error signal.
将期望与经验进行比较是大脑中广泛进行的一项重要神经计算，也是预测性处理的一个标志。改变动物行为感觉结果的实验表明，对意外的自我产生的刺激，神经反应增强，这表明感觉皮层中的神经元群体可能反映预测误差——期望与经验之间的不匹配。然而，对自我产生的刺激增强的神经反应也可能通过非预测机制产生，例如基于运动对神经元固有声音反应的促进作用。如果感觉皮层中存在感觉预测误差神经元，那么它们是表现为一般的误差反应，还是对不同刺激维度中的误差有特异性反应，目前尚不清楚。为了回答这些问题，我们训练小鼠预测一种简单发声行为的结果，并在小鼠听到预期声音或在多个不同维度之一偏离预期的声音时，记录听觉皮层的活动。我们的数据表明，听觉皮层学会了同时抑制沿多个声学维度对自我产生声音的反应。我们识别出一群独特的听觉皮层神经元，它们对被动声音或预期声音没有反应，但能明确编码预测误差。这些预测误差神经元仅在具有习得的运动-感觉期望的动物中大量存在，并且编码一两种特定的违反情况，而不是一般的误差信号。
