Francis G
Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907-1364, USA.
Spat Vis. 1999;12(1):31-50. doi: 10.1163/156856899x00021.
Psychophysical studies show that the duration of visual persistence increases with spatial frequency of gratings. Previous theories ascribe this finding to differences between the spatial and temporal properties of sustained and transient pathways. This paper proposes an alternative account that explains persistence as a side-effect of excitatory feedback in neural circuits for contour extraction. Mechanisms to break excitatory feedback include inhibitory reset signals at stimulus offset. Simulations demonstrate how gratings with lower spatial frequency generate stronger inhibitory reset signals, thereby resulting in shorter persistence for lower spatial frequencies. Additional simulations account for interactions of spatial frequency with stimulus duration, effects of adaptation, and properties of residual traces, as opposed to visual persistence.
心理物理学研究表明，视觉暂留的持续时间会随着光栅的空间频率增加。以往的理论将这一发现归因于持续性和瞬态通路在空间和时间特性上的差异。本文提出了另一种解释，将暂留解释为用于轮廓提取的神经回路中兴奋性反馈的副作用。打破兴奋性反馈的机制包括刺激消失时的抑制性重置信号。模拟结果表明，较低空间频率的光栅如何产生更强的抑制性重置信号，从而导致较低空间频率的暂留时间更短。额外的模拟解释了空间频率与刺激持续时间的相互作用、适应性的影响以及残留痕迹的特性，而非视觉暂留。
