Neural basis of pattern masking and texture segregation

描述（由申请人提供）：神经元是基本的处理 大脑中的单位;然而，尚不清楚神经活动如何导致 复杂的过程，如感知和行为。通过探索神经 信号的基础人类模式的视觉，拟议的实验将测试 假设这些过程是由许多细胞的汇集活动介导的， 神经元在所有三个实验中使用的一般方法是将 刺激引起的神经活动的心理物理感知， 早期视觉区域的刺激，通过fMRI测量。在第一个实验中， 探讨了模式掩蔽的神经基础。受试者进行对比 辨别任务，而神经活动通过fMRI测量。的 该提案中报告的初步数据显示，在刺激条件下， 从而产生掩蔽，对目标的神经反应被抑制。 将对该数据和其他受试者的数据进行进一步分析 通过同时拟合心理物理学和功能磁共振成像数据， 标准化函数与几个决策规则，试图确定 在模式检测任务中汇集信息。第二个目标扩展到 第一次的结果。模式可以被发生的刺激所掩盖 前向屏蔽（Forward Masking）在第三个实验中， 看看V1之外的神经信号，并表明神经信号编码感知经验， 而不是纹理辨别任务中刺激的物理特征。

DESCRIPTION (provided by applicant): Neurons are the fundamental processing unit in the brain; however, it is not known how neural activity leads to complex processes such as perception and behavior. By exploring the neural signals which underlie human pattern vision, the proposed experiments will test the hypothesis that these processes are mediated by the pooled activity of many neurons. The general approach used in all three experiments is to link psychophysical perception of a stimulus to the neural activity evoked by that stimulus in early visual areas as measured by fMRI. In the first experiment, the neural basis of pattern masking is explored. Subjects perform a contrast discrimination task while the neural activity is measured by fMRI. The preliminary data reported in this proposal show that under stimulus conditions which produce masking, the neural responses to the target are suppressed. Further analysis will be done on this data and on data from additional subjects by simultaneously fitting the psychophysical and fMRI data with a response normalization function with several decision rules to try to identify which information is pooled in a pattern detection task. The second aim expands on the results of the firsts. Patterns can be masked by stimuli which occur asynchronously (forward masking). In the third the experiments are extended to look outside V1 and show that neural signals code for perceptual experience and not physical features of a stimulus in a texture discrimination task.