知觉学习影响视觉刺激显著性的神经机制

项目名称： 知觉学习影响视觉刺激显著性的神经机制

项目编号： No.31500851

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 神经、认识与心理学

项目作者： 阎崟

作者单位： 北京师范大学

项目金额： 21万元

中文摘要： 图形背景中具有与众不同特征的视觉刺激可以在没有主动注意的情况下被视觉系统自动检测到并吸引注意，称为视觉刺激显著性。这种显著性可以由输入物理刺激某一特征的强烈反差引起，也可以通过后天经验和训练形成，即原先不显著的目标可以通过训练变得显著。研究发现特征强烈反差引起的显著性主要由初级视皮层（V1）神经元编码，而依赖于后天经验和知觉训练形成的显著性的机制尚不清楚。. 本项目计划利用植入式电极阵列技术，在训练猕猴执行视觉显著性检测任务的过程中跟踪记录大量V1神经元的电活动，考察训练过程中V1神经元群体编码特性的变化及其与猕猴显著性检测能力提高的关系。并通过控制物理刺激特征的反差强度，研究不需要训练就存在显著性的强反差刺激，与训练后才产生显著性的弱反差刺激在神经元编码机制上的异同，揭示知觉学习对视觉刺激显著性编码的影响及其神经机制。本研究对理解视觉显著性加工机制和视知觉学习的机制将具有重要意义。

中文关键词： 视皮层；知觉显著性；神经编码；知觉学习；感受野

英文摘要： A visual stimulus with a sharp contrast in its feature against a background of stimuli can be detected effortlessly by the visual system and automatically attracts attention, which is defined as visual saliency. Visual saliency effects can be caused not only by large contrasts between stimulus features but also by experience and training. A non-salient visual target with a low feature contrast among distracters could also become perceptually salient after extensive training. Previous studies have shown that visual saliency defined by stimulus feature contrast is processed in the primary visual cortex (V1); however, the mechanism of experience and training dependent saliency is still largely unknown. . In this proposed project, by implanting microelectrode arrays in monkey’s V1, we are going to investigate the dynamics of neuronal population coding during the course of training in visual saliency detection task. We will examine the relationship between the changes in response properties of V1 neurons and the changes in the monkey’s behavior performance on the detection task. In addition, by examining visual stimuli with different degrees of feature contrast, we will explore the differences and similarities in the neural codes between feature-defined and experience-dependent visual saliencies. These proposed studies will make significant contributions to understanding of the neural mechanism underlying visual saliency coding and visual perceptual learning.

英文关键词： visual cortex;perceptual saliency;neural coding;perceptual learning;receptive field