Center for Mind and Brain, University of California, Davis, California 95618, USA.
J Neurosci. 2012 Aug 1;32(31):10725-36. doi: 10.1523/JNEUROSCI.1864-12.2012.
Much is known about the mechanisms by which attention is focused to facilitate perception, but little is known about what happens to attention after perception of the attended object is complete. One possibility is that the focus of attention passively fades. A second possibility is that attention is actively terminated after the completion of perception so that the brain can be prepared for the next target. The present study investigated this issue with event-related potentials in humans, focusing on the N2pc component (a neural measure of attentional deployment) and the Pd component (a neural measure of attentional suppression). We found that active suppression occurred both to prevent the allocation of attention to known distractors and to terminate attention after the perception of an attended object was complete. In addition, the neural measure of active suppression was correlated with a behavioral measure of trial-to-trial variations in the allocation of attention. Active suppression therefore appears to be a general-purpose mechanism that both prevents and terminates the allocation of attention.
关于注意力集中的机制，以便促进感知，人们已经了解了很多，但对于感知完被注意的物体后注意力会发生什么，人们知之甚少。一种可能是注意力的焦点被动地消失。另一种可能是在感知完成后，注意力被主动终止，以便大脑为下一个目标做好准备。本研究使用人类事件相关电位来研究这个问题，重点关注 N2pc 成分（注意力部署的神经测量）和 Pd 成分（注意力抑制的神经测量）。我们发现，主动抑制既发生在防止注意力分配给已知干扰物上，也发生在感知到被注意的物体后终止注意力上。此外，主动抑制的神经测量与注意力分配在试验间变化的行为测量相关。因此，主动抑制似乎是一种通用机制，既可以防止也可以终止注意力的分配。
