Department of Biology, Centre for Vision Research, York University, Toronto, Ontario, Canada.
PLoS Biol. 2011 Dec;9(12):e1001224. doi: 10.1371/journal.pbio.1001224. Epub 2011 Dec 27.
Attentional control ensures that neuronal processes prioritize the most relevant stimulus in a given environment. Controlling which stimulus is attended thus originates from neurons encoding the relevance of stimuli, i.e. their expected value, in hand with neurons encoding contextual information about stimulus locations, features, and rules that guide the conditional allocation of attention. Here, we examined how these distinct processes are encoded and integrated in macaque prefrontal cortex (PFC) by mapping their functional topographies at the time of attentional stimulus selection. We find confined clusters of neurons in ventromedial PFC (vmPFC) that predominantly convey stimulus valuation information during attention shifts. These valuation signals were topographically largely separated from neurons predicting the stimulus location to which attention covertly shifted, and which were evident across the complete medial-to-lateral extent of the PFC, encompassing anterior cingulate cortex (ACC), and lateral PFC (LPFC). LPFC responses showed particularly early-onset selectivity and primarily facilitated attention shifts to contralateral targets. Spatial selectivity within ACC was delayed and heterogeneous, with similar proportions of facilitated and suppressed responses during contralateral attention shifts. The integration of spatial and valuation signals about attentional target stimuli was observed in a confined cluster of neurons at the intersection of vmPFC, ACC, and LPFC. These results suggest that valuation processes reflecting stimulus-specific outcome predictions are recruited during covert attentional control. Value predictions and the spatial identification of attentional targets were conveyed by largely separate neuronal populations, but were integrated locally at the intersection of three major prefrontal areas, which may constitute a functional hub within the larger attentional control network.
注意控制确保神经元过程优先处理给定环境中最相关的刺激。控制注意力集中的刺激源，因此源于编码刺激相关性的神经元，即它们的预期价值，以及编码关于刺激位置、特征和规则的上下文信息的神经元，这些信息指导注意力的条件分配。在这里，我们通过在注意力刺激选择时绘制它们的功能地形图，研究了这些不同的过程是如何在猕猴前额叶皮层（PFC）中被编码和整合的。我们发现腹内侧前额叶皮层（vmPFC）中有局限的神经元簇，它们在注意力转移期间主要传递刺激估值信息。这些估值信号在地形上与预测注意力暗中转移到的刺激位置的神经元有很大的分离，这些神经元在 PFC 的整个从内侧到外侧的范围内都是明显的，包括前扣带皮层（ACC）和外侧前额叶皮层（LPFC）。LPFC 的反应表现出特别早的选择性，主要促进对侧目标的注意力转移。ACC 内的空间选择性延迟且异质，在对侧注意力转移期间，促进和抑制反应的比例相似。在 vmPFC、ACC 和 LPFC 的交点处观察到注意力目标刺激的空间和估值信号的整合。这些结果表明，反映刺激特定结果预测的估值过程在隐蔽性注意力控制期间被招募。价值预测和注意力目标的空间识别由很大程度上分离的神经元群体传递，但在三个主要前额叶区域的交点处进行局部整合，这可能构成更大注意力控制网络中的一个功能枢纽。
