Responses to task-irrelevant visual features by primate prefrontal neurons
Responses to task-irrelevant visual features by primate prefrontal neurons
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DOI：
10.1152/jn.2001.86.4.2001
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发表时间：
2001-10-01
影响因子：
2.5
通讯作者：
Hikosaka, O
中科院分区：
文献类型：
--
作者：
Lauwereyns, J;Sakagami, M;Hikosaka, O
灵长类动物的大脑配备了用于解释视觉信息的前额叶回路，但这些回路如何处理竞争性刺激-反应（S-R）关联仍然未知。本研究显示了三个功能分离组对与任务无关的视觉特征的不同反应类型。灵长类动物前额叶神经元。两只日本猕猴参加了一个“走”或“不走”的任务，在这个任务中，它们必须辨别视觉目标的颜色或运动方向，以做出正确的手动反应。在实验之前，猴子们已经接受了广泛的训练，以便他们获得视觉特征和所需反应之间的固定联系（例如，“绿色=通行”；“向下运动=不通行”）。在这个设计中，猴子面对一个视觉目标，它必须从中提取相关信息（如辨色条件下的颜色），而忽略无关信息（如辨色条件下的运动方向）。我们记录了436个与任务相关的前额叶神经元，当猴子执行多维去/不去任务时：139个（32%）神经元显示出基于颜色和运动方向的去/不去区分（“整合细胞”）；192个神经元（44%）表现出仅基于颜色（“颜色特征细胞”）的去/不去区分；105个神经元（24%）仅根据运动方向（“运动特征细胞”）表现出去/不去的区分。然而，总的来说，162个神经元（37%）受到不相关信息的影响：整合细胞中有53个神经元（38%），颜色特征细胞中有71个神经元（37%），运动特征细胞中有38个神经元（36%）。在所有类型的神经元中，对不相关特征的反应与对相关特征的反应呈正相关，这表明不相关信息的影响是在不同背景下相关的S-R关联的残余。整合细胞、颜色特征细胞和运动特征细胞在时间和解剖上的差异表明，前额叶皮层的信息加工模式是顺序的，整合细胞位于决策过程的输出端。在这些细胞中，对不相关信息的反应表现为一致性效应，当相关和不相关的特征与相同的反应相关联时，比当它们与不同的反应相关联时，有更好的去/不去区分。这种一致性效应可能是颜色和运动特征细胞联合输入的结果。因此，这些数据表明，不相关的特征导致神经元的部分激活，甚至是对灵长类动物前额叶皮层决策过程的输出。
The primate brain is equipped with prefrontal circuits for interpreting visual information, but how these circuits deal with competing stimulus-response (S-R) associations remains unknown. Here we show different types of responses to task-irrelevant visual features in three functionally dissociated group., of primate prefrontal neurons. Two Japanese macaques participated in a go/no-go task in which they had to discriminate either the color or the motion direction of a visual target to make a correct manual response. Prior to the experiment, the monkeys had been trained extensively so that they acquired fixed associations between visual features and required responses (e.g., "green = go"; "downward motion = no-go"). In this design, the monkey was confronted with a visual target from which it had to extract relevant information (e.g., color in the color-discrimination condition) while ignoring irrelevant information (e.g., motion direction in the color-discrimination condition). We recorded from 436 task-related prefrontal neurons while the monkey performed the multidimensional go/ no-go task: 139 (32%) neurons showed go/no-go discrimination based on color as well as motion direction ("integration cells"); 192 neurons (44%) showed go/no-go discrimination only based on color ("color-feature cells"); and 105 neurons (24%) showed go/no-go discrimination only based on motion direction ("motion-feature cells"). Overall, however, 162 neurons (37%) were influenced by irrelevant information: 53 neurons (38%) among integration cells, 71 neurons (37%) among color-feature cells, and 38 neurons (36%) among motion-feature cells. Across all types of neurons, the response to an irrelevant feature was positively correlated with the response to the same feature when it was relevant, indicating that the influence from irrelevant information is a residual from S-R associations that are relevant in a different context. Temporal and anatomical differences among integration, color-feature and motion-feature cells suggested a sequential mode of information processing in prefrontal cortex, with integration cells situated toward the output of the decision-making process. In these cells, the response to irrelevant information appears as a congruency effect, with better go/no-go discrimination when both the relevant and irrelevant feature are associated with the same response than when they are associated with different responses. This congruency effect could be the result of the combined input from color- and motion-feature cells. Thus these data suggest that irrelevant features lead to partial activation of neurons even toward the output of the decision-making process in primate prefrontal cortex.