Smith A T, Singh K D, Greenlee M W
Department of Psychology, Royal Holloway, University of London, Egham, UK.
Neuroreport. 2000 Feb 7;11(2):271-7. doi: 10.1097/00001756-200002070-00010.
We have used fMRI to examine the nature of the changes that occur in the human visual cortex when an observer attends to a particular location in the visual image. Previous studies have shown that the magnitude of the response to a visual stimulus is increased when the observer attends to the stimulus. We show that, in addition, attention to a particular location results in a widespread suppression of activity levels at all other locations. This suggests that a key mechanism of attentional modulation may be that spontaneous (baseline) levels of neural activity are adjusted in a position-dependent manner across the entire visual field.
我们使用功能磁共振成像（fMRI）来研究当观察者关注视觉图像中的特定位置时，人类视觉皮层中发生的变化的本质。先前的研究表明，当观察者关注某一视觉刺激时，对该刺激的反应强度会增加。我们还发现，此外，对特定位置的关注会导致对所有其他位置的活动水平产生广泛抑制。这表明注意力调制的一个关键机制可能是，神经活动的自发（基线）水平在整个视野中以位置依赖的方式进行调整。
