A relationship between behavioral choice and the visual responses of neurons in macaque MT
A relationship between behavioral choice and the visual responses of neurons in macaque MT
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DOI：
10.1017/s095252380000715x
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发表时间：
1996-01-01
影响因子：
1.9
通讯作者：
Movshon, JA
中科院分区：
文献类型：
--
作者：
Britten, KH;Newsome, WT;Movshon, JA
我们之前通过研究外纹状区MT神经元的反应与其感受野中视觉运动信号的方向和强度之间的关系，记录了这些神经元极高的运动敏感性。这些结果表明，MT神经元可能为视觉辨别任务中的行为选择提供支持信号。为了从另一个角度探讨这个问题，我们现在研究了MT神经元的放电与行为选择之间的关系，且不受视觉刺激的影响。我们发现神经元信号在每次试验中的变异性与猴子所做的选择相关。因此，当MT区的一个方向选择性神经元更强烈地放电时，猴子更有可能做出有利于该细胞偏好方向的决策。这种关系的程度平均而言较为适中，但在来自四只猴子的299个细胞样本中具有高度显著性。这种关系存在于所有刺激（包括那些没有净运动信号的刺激）中，并且除了最弱的反应外都存在。当任务要求改变，使得细胞所携带的方向信号信息量减少时，这种关系会减弱或消失。这种关系在反应开始后的50毫秒内就很明显，并在整个刺激呈现过程中持续存在。平均而言，对微弱运动信号更敏感的神经元与行为的关系比那些不太敏感的神经元更强。这些观察结果与猴子利用MT中的神经元信号来确定刺激运动方向的观点是一致的。行为选择与任何一个神经元放电之间的适度关系，以及这种关系在整个神经元群体中的普遍性，使得很可能是许多神经元的信号被汇集起来，形成了行为选择所依据的数据。
We have previously documented the exquisite motion sensitivity of neurons in extrastriate area MT by studying the relationship between their responses and the direction and strength of visual motion signals delivered to their receptive fields. These results suggested that MT neurons might provide the signals supporting behavioral choice in visual discrimination tasks. To approach this question from another direction, we have now studied the relationship between the discharge of MT neurons and behavioral choice, independently of the effects of visual stimulation. We found that trial-to-trial variability in neuronal signals was correlated with the choices the monkey made. Therefore, when a directionally selective neuron in area MT fires more vigorously, the monkey is more likely to make a decision in favor of the preferred direction of the cell. The magnitude of the relationship was modest, on average, but was highly significant across a sample of 299 cells from four monkeys. The relationship was present for all stimuli (including those without a net motion signal), and for all but the weakest responses. The relationship was reduced or eliminated when the demands of the task were changed so that the directional signal carried by the cell was less informative. The relationship was evident within 50 ms of response onset, and persisted throughout the stimulus presentation. On average, neurons that were more sensitive to weak motion signals had a stronger relationship to behavior than those that were less sensitive. These observations are consistent with the idea that neuronal signals in MT are used by the monkey to determine the direction of stimulus motion. The modest relationship between behavioral choice and the discharge of any one neuron, and the prevalence of the relationship across the population, make it likely that signals from many neurons are pooled to form the data on which behavioral choices are based.