Ghose Geoffrey M, Maunsell John H R
Division of Neuroscience and Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA.
Nature. 2002 Oct 10;419(6907):616-20. doi: 10.1038/nature01057.
Paying attention to a stimulus selectively increases the ability to process it. For example, when subjects attend to a specific region of a visual scene, their sensitivity to changes at that location increases. A large number of studies describe the behavioural consequences and neurophysiological correlates of attending to spatial locations. There has, in contrast, been little study of the allocation of attention over time. Because subjects can anticipate predictable events with great temporal precision, it seems probable that they might dynamically shift their attention when performing a familiar perceptual task whose constraints changed over time. We trained monkeys to respond to a stimulus change where the probability of occurrence changed over time. Recording from area V4 of the visual cortex in these animals, we found that the modulation of neuronal responses changed according to the probability of the change occurring at that instant. Thus, we show that the attentional modulation of sensory neurons reflects a subject's anticipation of the timing of behaviourally relevant events.
选择性地关注某一刺激会增强对其进行处理的能力。例如，当受试者关注视觉场景中的特定区域时，他们对该位置变化的敏感度会提高。大量研究描述了关注空间位置的行为后果和神经生理相关性。相比之下，对于注意力随时间的分配研究较少。由于受试者能够以很高的时间精度预测可预测的事件，所以当他们执行一项熟悉的感知任务，且任务的限制条件随时间变化时，他们似乎有可能动态地转移注意力。我们训练猴子对刺激变化做出反应，其中刺激出现的概率随时间变化。通过记录这些动物视觉皮层V4区的活动，我们发现神经元反应的调制根据该时刻变化发生的概率而改变。因此，我们表明感觉神经元的注意力调制反映了受试者对行为相关事件发生时间的预期。
