Rule-dependent neuronal activity in the prefrontal cortex
Rule-dependent neuronal activity in the prefrontal cortex
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DOI：
10.1007/s002210050740
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发表时间：
1999-06-01
影响因子：
2
通讯作者：
Wise, SP
中科院分区：
文献类型：
--
作者：
White, IM;Wise, SP
我们研究了前额叶皮层（PF）的单神经元活动，而猴子根据两种不同的规则执行任务，称为条件和空间。猴子观看视频屏幕，它的任务需要手部运动以响应光点的变暗。屏幕上有四个光点，从中心开始，分别是右、左、上、下。四个光点中只有一个黯淡了下来，而且黯淡的程度很轻微。因此，猴子需要凹进“正确”的光点来检测变暗。视觉提示指示四个光点中的哪一个将被认为是正确的，因此在每次试验中将变暗。事件的顺序如下：一个固定点出现在屏幕的中心;然后，一个提示出现在四个潜在目标位置之一的两次;然后，四个目标点出现;最后，其中一个变暗。除了初始注视点的颜色，线索，它们的位置，以及其他事件是相同的条件和空间规则。这些规则在一个重要方面有所不同。对于条件规则，视觉线索的非空间属性表明四个光点中的哪一个会变暗，而线索的位置无关紧要。对于空间规则，线索的位置决定了试验中正确的目标。无论哪一个提示出现在那里，提示位置的光点总是暗淡的。我们的样本包括221个PF神经元显示出显着的任务相关的活动调制，分布在背侧，背外侧和腹侧PF区域。在这些区域中，每个区域都有三分之一至二分之一的样本显示出可归因于这一规则的统计上显著的活动差异。对线索和/或它们的位置的选择性是常见的。然而，在这种选择性方面没有明显的区域差别。这些数据支持这一假设，即PF发挥了作用，在指导行为，根据以前学到的规则。
We studied single-neuron activity in the prefrontal cortex (PF) while a monkey performed a task according to two different rules, termed conditional and spatial. The monkey viewed a Video screen, and its task required a hand movement in response to the dimming of a light spot. There were four light spots on the screen: right, left, up, and down from the center. Only one of the four spots dimmed, and the degree of dimming was slight. Accordingly, the monkey needed to foveate the "correct" light spot to detect the dimming. A visual cue indicated which of the four light spots would be deemed correct and, thus, would dim on each trial. The sequence of events was as follows: a fixation spot appeared at the center of the screen; then, a cue appeared twice at one of the four potential target locations; then, the four target spots appeared; and, finally, one of them dimmed. Except for the color of an initial fixation point, the cues, their locations, and other events were identical for the conditional and spatial rules. The rules differed in one essential way. For the conditional rule, nonspatial attributes of the visual cue indicated which of the four light spots would dim, and the cue's location was irrelevant. For the spatial rule, the cue's location determined the correct target on that trial. The light spot at the location of the cue always dimmed, regardless of which cue appeared there. Our sample included 221 PF neurons showing significant task-related activity modulation, distributed among dorsal, dorsolateral, and ventral PF regions. Between one-third and one-half of the sample in each of those regions showed statistically significant activity differences that could be attributed to the rule. Selectivity for cues and/or their locations was common. However, there was no significant regional segregation of such selectivity. These data support the hypothesis that PF plays a role in the guidance of behavior according to previously learned rules.