人类视觉信息加工的可塑性研究

The project will take advantage of perceptual learning to study the plasticity of human visual information processing in adult brain. As a hot research topic, perceptual learning is on the cutting edge of cognitive neuroscience research. However, we still know little about its neural mechanism though the existence of so many theoretical debates. A major reason is that perceptual learning research is very difficulty to perform, thus not much brain imaging and neurophysiological data available. Here, we will combine psychophysics, brain imaging (i.e. functional magnetic resonance imaging, high-density event-related potentials and transcranial magnetic stimulation) and computational modeling to study perceptual learning systematically and comprehensively. In the first part of the project, we will study perceptual learning of orientation, motion, shape and face. We are interested in the general and specific mechanisms for the four kinds of perceptual learning. In the second part, we will investigate the modulation mechanisms of high-level cognitive factors (i.e. attention, consciousness and award) on perceptual learning. The project will provide psychophysical,brain imaging and modeling evidence to shed light on the neural mechanisms of perceptual learning. Meanwhile, it will significantly advance experimental techniques and methodology for perceptual learning research.

本项目以知觉学习为切入点研究人类视觉信息加工的可塑性。知觉学习是目前认知神经科学研究的前沿问题和热点问题，对它的认知神经机制研究具有1)理论争论多；2）研究难度大；3）脑成像和神经生理数据少等特点。我们将结合心理物理学、脑成像（包括功能性磁共振、高密度脑电和经颅磁刺激）和计算模型对知觉学习进行系统的、全方位探讨。本项目分为两个部分。第一部分研究朝向、运动、形状和面孔四种具有典型意义的知觉学习，探讨不同类型知觉学习的普遍性机制和特异性机制。第二部分研究注意、意识和奖赏等高级认知成分对知觉学习的调控机制。本项目将为人类大脑可塑性的认知神经机制从心理物理层面到脑成像层面到模型层面提供原创的、系统性的实验与理论证据，同时在可塑性研究的实验技术和方法上有所突破。

本项目以知觉学习为切入点研究人类视觉信息加工的可塑性。我们结合心理物理学、磁共振成像、高密度脑电、经颅磁刺激和计算模型对知觉学习进行系统的、全方位探讨。本项目分为三个部分。第一部分研究对比度、朝向、运动和面孔四种具有典型意义的知觉学习，探讨不同类型知觉学习的普遍性机制和特异性机制。主要发现包括 1）感觉加工阶段的编码精确程度的改变和决策阶段的权重调节可能是知觉学习的关键机制；2）首次发现知觉学习可以改变皮层下核团（外侧膝状体）的功能，是对比度学习的关键脑区；3）知觉学习可以改变脑区功能特异性，并引起脑区间功能替代。第二部分揭示了奖赏、注意、和意识等高级认知成分对学习和可塑性的调控机制。第三部分利用视觉适应诱发的短时可塑性探索运动、对比度、朝向和颜色加工的神经机制。本项目为人类大脑可塑性的认知神经机制从心理物理层面到脑成像层面提供原创的、系统性的实验与理论证据，同时在可塑性研究的实验技术和方法上有所突破。