感知分辨能力经过训练而提高的现象称为知觉学习。由于缺乏有力的生理学证据,已往主要基于行为和脑成像的研究存在分歧,焦点在于知觉学习发生的脑区和编码形式。近年来,结合心理物理和清醒猴电生理的系列研究表明,视觉检测训练可以优化大脑初级视皮层神经元的编码,该过程依赖于自上而下的信号调控。这些发现提示,知觉学习改变了前馈输入和反馈信号之间的相互作用。这种多脑区间的协同编码机制为理解学习与脑的可塑性提供了新的视角。
Our perceptual abilities can be significantly improved with training, a process referred to as perceptual learning. Due to a lack of compelling physiological evidence, previous psychophysical and imaging studies have provided controversial results and interpretations in terms of the cortical loci and the neural codes of perceptual learning. By combining behavioral approach with electrophysiological recording in awake monkeys, our recent studies showed that visual perceptual training leads to a remarkable refinement of neural code in the primary visual cortex. This process depends on task-specific top-down modulatory signals. The converging evidence indicates that perceptual learning results from a complex interplay between bottom-up sensory inputs and top-down feedback signals. Such a synergistic processing mechanism among multiple cortical areas provides insight into learning and brain plasticity in general.