Department of Psychology, Graduate School of Humanities, Chiba University, Inage-ku, Chiba-shi, Chiba, Japan.
J Vis. 2023 Aug 1;23(8):1. doi: 10.1167/jov.23.8.1.
Quantifying visual responses to stimuli that are outside of awareness is a critical task for the study of visual consciousness. The current study psychophysically investigated whether afterimages reflect visual responses to stimuli that are not consciously visible throughout adaptation due to interocular suppression. A Gabor adaptor was presented to one eye of the observer, and a counterphase-flickering Gabor suppressor was presented to the other eye, thereby rendering the adaptor invisible during adaptation. To manipulate the depth of the suppression of the invisible adaptor, we varied the orientation difference between the adaptor and suppressor. We found that, even though the adaptor was not visible during adaptation, the afterimage duration varied depending on the orientation selectivity of interocular suppression. The duration was the shortest when the orientations of the adaptor and suppressor were identical and lengthened when the orientation differences increased. This finding could not be explained by confounding factors such as potential changes in contrast sensitivity that were caused by the suppressor. Our findings suggest that the magnitude of visual responses to stimuli suppressed below the threshold of awareness can be measured using the afterimage duration. Afterimages could be an effective tool for quantifying visual responses, irrespective of observers' conscious awareness of a presented stimulus.
量化对意识之外刺激的视觉反应是视觉意识研究的一个关键任务。本研究通过心理物理学方法研究了后像是否反映了由于眼间抑制而在适应过程中始终无法意识到的刺激的视觉反应。将一个 Gabor 适应器呈现给观察者的一只眼睛，同时将一个反相闪烁的 Gabor 抑制器呈现给另一只眼睛，从而使适应器在适应过程中不可见。为了操纵不可见适应器抑制的深度，我们改变了适应器和抑制器之间的方向差异。我们发现，即使适应器在适应过程中不可见，但后像持续时间取决于眼间抑制的方向选择性。当适应器和抑制器的方向相同时，持续时间最短，当方向差异增加时，持续时间延长。这一发现不能用潜在的抑制器引起的对比度敏感度变化等混杂因素来解释。我们的发现表明，可以使用后像持续时间来测量对低于意识阈值的刺激的视觉反应的大小。后像可能是一种有效的工具，可以量化视觉反应，而不论观察者对呈现的刺激是否有意识。
