NEURAL MECHANISMS FOR FORMING A PERCEPTUAL DECISION
NEURAL MECHANISMS FOR FORMING A PERCEPTUAL DECISION
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DOI：
10.1126/science.8146653
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发表时间：
1994-04-08
期刊：
影响因子：
56.9
通讯作者：
NEWSOME, WT
中科院分区：
文献类型：
--
作者：
SALZMAN, CD;NEWSOME, WT
对环境刺激的认知和行为反应取决于对大脑皮层内感觉信号的评估。用生理和心理物理技术相结合的方法研究了这种现象在特定视觉任务中发生的机制。恒河猴在8个可能的运动方向中辨别，而方向信号在视觉区域MT中被操纵。一个方向信号是由视觉刺激产生的，第二个信号是通过电刺激神经元产生的，这些神经元编码了特定的运动方向。猴子对这两个信号做出的决定使得在MT中解释方向信号的两种可能机制之间有了区别。猴子倾向于做出有利于一个或另一个信号的决定，这表明这些信号对表现产生了独立的影响，而诸如两个信号的向量平均之类的交互机制并不起作用。因此，这些数据提出了一种机制，在这种机制中，猴子选择由运动方向表示中的最大信号编码的方向，这是一个“赢家通吃”的决定过程。
Cognitive and behavioral responses to environmental stimuli depend on an evaluation of sensory signals within the cerebral cortex. The mechanism by which this occurs in a specific visual task was investigated with a combination of physiological and psychophysical techniques. Rhesus monkeys discriminated among eight possible directions of motion while directional signals were manipulated in visual area MT. One directional signal was generated by a visual stimulus and a second signal was introduced by electrically stimulating neurons that encoded a specific direction of motion. The decisions made by the monkeys in response to the two signals allowed a distinction to be made between two possible mechanisms for interpreting directional signals in MT. The monkeys tended to cast decisions in favor of one or the other signal, indicating that the signals exerted independent effects on performance and that an interactive mechanism such as vector averaging of the two signals was not operative. Thus, the data suggest a mechanism in which monkeys chose the direction encoded by the largest signal in the representation of motion direction, a ''winner-take-all'' decision process.