Cognitive Neuroscience Laboratory, German Primate Center, Kellnerweg 4, 37077, Goettingen, Germany.
Center for Mind and Brain Sciences, University of Trento, Via delle Regole 101, 38123, Mattarello, TN, Italy.
Sci Rep. 2020 Mar 6;10(1):4216. doi: 10.1038/s41598-020-61171-3.
The lateral prefrontal cortex of primates (lPFC) plays a central role in complex cognitive behavior, in decision-making as well as in guiding top-down attention. However, how and where in lPFC such behaviorally relevant signals are computed is poorly understood. We analyzed neural recordings from chronic microelectrode arrays implanted in lPFC region 8Av/45 of two rhesus macaques. The animals performed a feature match-to-sample task requiring them to match both motion and color information in a test stimulus. This task allowed to separate the encoding of stimulus motion and color from their current behavioral relevance on a trial-by-trial basis. We found that upcoming motor behavior can be robustly predicted from lPFC activity. In addition, we show that 8Av/45 encodes the color of a visual stimulus, regardless of its behavioral relevance. Most notably, whether a color matches the searched-for color can be decoded independent of a trial's motor outcome and while subjects detect unique feature conjunctions of color and motion. Thus, macaque area 8Av/45 computes, among other task-relevant information, the behavioral relevance of visual color features. Such a signal is most critical for both the selection of responses as well as the deployment of top-down modulatory signals, like feature-based attention.
灵长类动物的外侧前额叶皮层（lPFC）在复杂认知行为、决策以及引导自上而下的注意力方面起着核心作用。然而，在 lPFC 中，这些与行为相关的信号是如何以及在何处计算的，目前还知之甚少。我们分析了两只恒河猴植入 lPFC 区域 8Av/45 的慢性微电极阵列的神经记录。这些动物执行了一个特征匹配样本任务，要求它们在测试刺激中匹配运动和颜色信息。这个任务允许根据每个试验的基础来分离刺激运动和颜色的编码及其当前的行为相关性。我们发现，即将到来的运动行为可以从 lPFC 活动中可靠地预测。此外，我们还表明，8Av/45 编码了视觉刺激的颜色，而不管其行为相关性如何。最值得注意的是，无论一个颜色是否与搜索到的颜色匹配，都可以在不考虑试验的运动结果的情况下进行解码，而当被试检测到颜色和运动的独特特征结合时。因此，猕猴 8Av/45 区域除了计算其他与任务相关的信息外，还计算视觉颜色特征的行为相关性。这种信号对于选择反应以及部署基于特征的注意力等自上而下的调节信号至关重要。
