Department of Psychiatry, Columbia University, New York, NY 10032.
New York State Psychiatric Institute, New York, NY 10032.
Proc Natl Acad Sci U S A. 2017 Jun 6;114(23):6122-6126. doi: 10.1073/pnas.1609711114. Epub 2017 May 22.
Spatial cues allow animals to selectively attend to relevant visual stimuli while ignoring distracters. This process depends on a distributed neuronal network, and an important current challenge is to understand the functional contributions made by individual brain regions within this network and how these contributions interact. Recent findings point to a possible anatomical segregation, with cortical and subcortical brain regions contributing to different functional components of selective attention. Cortical areas, especially visual cortex, may be responsible for implementing changes in perceptual sensitivity by changing the signal-to-noise ratio, whereas other regions, such as the superior colliculus, may be involved in processes that influence selection between competing stimuli without regulating perceptual sensitivity. Such a segregation of function would predict that when activity in the superior colliculus is suppressed by reversible inactivation, animals should still show changes in perceptual sensitivity mediated by the intact cortical circuits. Contrary to this prediction, here we report that inactivation of the primate superior colliculus eliminates the changes in perceptual sensitivity made possible by spatial cues. These findings demonstrate changes in perceptual sensitivity depend not only on neuronal activity in cortex but also require interaction with signals from the superior colliculus.
空间提示使动物能够选择性地关注相关的视觉刺激，同时忽略干扰物。这个过程依赖于一个分布式的神经元网络，目前的一个重要挑战是了解该网络中各个脑区的功能贡献，以及这些贡献如何相互作用。最近的发现表明，可能存在一种解剖学上的分离，皮质和皮质下脑区分别对选择性注意的不同功能成分做出贡献。皮质区域，特别是视觉皮层，可能负责通过改变信噪比来实现感知敏感性的变化，而其他区域，如上丘，可能参与影响竞争刺激之间选择的过程，而不调节感知敏感性。这种功能的分离将预测，当上丘的活动被可逆失活抑制时，动物仍应该表现出由完整的皮质回路介导的感知敏感性变化。与这一预测相反，我们在这里报告，灵长类动物上丘的失活消除了空间提示所产生的感知敏感性变化。这些发现表明，感知敏感性的变化不仅取决于皮层中的神经元活动，还需要与来自上丘的信号相互作用。
