Wellcome Centre for Human Neuroimaging, Queen Square Institute of Neurology, University College London, London, UK.
Max Planck UCL Centre for Computational Psychiatry and Aging Research, University College London, London, UK.
J Vis. 2022 Feb 1;22(2):11. doi: 10.1167/jov.22.2.11.
Internally generated imagery and externally triggered perception rely on overlapping sensory processes. This overlap poses a challenge for perceptual reality monitoring: determining whether sensory signals reflect reality or imagination. In this study, we used psychophysics to investigate how imagery and perception interact to determine visual experience. Participants were instructed to detect oriented gratings that gradually appeared in noise while simultaneously either imagining the same grating, a grating perpendicular to the to-be-detected grating, or nothing. We found that, compared to both incongruent imagery and no imagery, congruent imagery caused a leftward shift of the psychometric function relating stimulus contrast to perceptual threshold. We discuss how this effect can best be explained by a model in which imagery adds sensory signal to the perceptual input, thereby increasing the visibility of perceived stimuli. These results suggest that, in contrast to changes in sensory signals caused by self-generated movement, the brain does not discount the influence of self-generated sensory signals on perception.
内源性表象和外源性感知依赖于重叠的感觉过程。这种重叠给感知现实监测带来了挑战：确定感觉信号是反映现实还是想象。在这项研究中，我们使用心理物理学来研究表象和感知如何相互作用来决定视觉体验。参与者被指示在噪声中逐渐检测到定向光栅，同时想象相同的光栅、与要检测的光栅垂直的光栅或什么都不做。我们发现，与不一致的表象和没有表象相比，一致的表象导致了将刺激对比度与感知阈值相关联的心理物理函数向左移动。我们讨论了如何最好地用一个模型来解释这个效应，该模型认为表象将感觉信号添加到感知输入中，从而增加了感知刺激的可见度。这些结果表明，与由自我产生的运动引起的感觉信号变化相反，大脑不会对自我产生的感觉信号对感知的影响进行折扣。
