Department of Psychology and Key Laboratory of Machine Perception (Ministry of Education), Peking University, Beijing 100871, China.
Neuron. 2012 Jan 12;73(1):183-92. doi: 10.1016/j.neuron.2011.10.035.
The bottom-up contribution to the allocation of exogenous attention is a saliency map, whose neural substrate is hard to identify because of possible contamination by top-down signals. We obviated this possibility using stimuli that observers could not perceive, but that nevertheless, through orientation contrast between foreground and background regions, attracted attention to improve a localized visual discrimination. When orientation contrast increased, so did the degree of attraction, and two physiological measures: the amplitude of the earliest (C1) component of the ERP, which is associated with primary visual cortex, and fMRI BOLD signals in areas V1-V4 (but not the intraparietal sulcus). Significantly, across observers, the degree of attraction correlated with the C1 amplitude and just the V1 BOLD signal. These findings strongly support the proposal that a bottom-up saliency map is created in V1, challenging the dominant view that the saliency map is generated in the parietal cortex.
自下而上对外部注意的分配是一个显著图，其神经基础很难确定，因为可能受到自上而下信号的污染。我们使用观察者无法感知但通过前景和背景区域之间的方向对比度吸引注意力以改善局部视觉辨别力的刺激来避免这种可能性。当方向对比度增加时，吸引力的程度也会增加，并且有两个生理测量指标：ERP 的最早（C1）成分的幅度，与初级视觉皮层相关联，以及 V1-V4 区域的 fMRI BOLD 信号（但不是顶内沟）。重要的是，在观察者之间，吸引力的程度与 C1 幅度和仅 V1 BOLD 信号相关。这些发现强烈支持了这样一种观点，即自下而上的显著图是在 V1 中创建的，这挑战了显著图是在顶叶皮层中产生的主导观点。
