State University of New York at Binghamton.
Johns Hopkins University.
J Cogn Neurosci. 2022 Mar 31;34(5):787-805. doi: 10.1162/jocn_a_01827.
There has been a longstanding debate as to whether salient stimuli have the power to involuntarily capture attention. As a potential resolution to this debate, the signal suppression hypothesis proposes that salient items generate a bottom-up signal that automatically attracts attention, but that salient items can be suppressed by top-down mechanisms to prevent attentional capture. Despite much support, the signal suppression hypothesis has been challenged on the grounds that many prior studies may have used color singletons with relatively low salience that are too weak to capture attention. The current study addressed this by using previous methods to study suppression but increased the set size to improve the relative salience of the color singletons. To assess whether salient distractors captured attention, electrophysiological markers of attentional allocation (the N2pc component) and suppression (the PD component) were measured. The results provided no evidence of attentional capture, but instead indicated suppression of the highly salient singleton distractors, as indexed by the PD component. This suppression occurred even though a computational model of saliency confirmed that the color singleton was highly salient. Altogether, this supports the signal suppression hypothesis and is inconsistent with stimulus-driven models of attentional capture.
关于显著刺激是否具有无意识捕获注意力的能力，一直存在着长期的争论。作为对这一争论的潜在解决方案，信号抑制假说提出，显著项目产生的自下而上的信号会自动吸引注意力，但显著项目可以被自上而下的机制抑制，以防止注意力捕获。尽管得到了广泛的支持，但信号抑制假说受到了挑战，其理由是，许多先前的研究可能使用了相对低显著度的颜色单音，其强度太弱，无法吸引注意力。本研究通过使用先前的方法来研究抑制，但增加了集合大小，以提高颜色单音的相对显著度。为了评估显著的分心物是否捕获了注意力，测量了注意分配的电生理标记（N2pc 成分）和抑制（PD 成分）。结果没有提供注意力捕获的证据，而是表明高度显著的单一干扰物被抑制，这一结果由 PD 成分索引。即使一个关于显著性的计算模型确认了颜色单音的高度显著性，这种抑制仍然存在。总的来说，这支持了信号抑制假说，与注意力捕获的刺激驱动模型不一致。
