闪光滞后效应并非知觉延迟差异所致

The Flash-Lag Effect:Latency Difference Is Not the Cause

闪光滞后效应(flash-lag effect)是指在与运动物体一致的位置上呈现闪光(flash),知觉上闪光落后于运动物体的视错觉。延迟差异理论认为,产生该现象的原因是视觉系统加工闪光的速度比加工运动物体慢。根据该理论,作者预测:如采用知觉加工速度更快(或更慢)的客体替代闪光,应能相应地产生更小(或更大)的闪光滞后效应。为了检验该预测,作者以"客体突现"(onset)和"客体消失"(offset)替代闪光滞后实验中的闪光,结果发现,"突现"的知觉滞后大于"消失",但时序判断任务表明"突现"的知觉延迟比"消失"短。该结果并不支持延迟差异理论。

The flash-lag effect is a robust visual illusion in which a flash appears to spatially lag a continuously moving stimulus, even though actually both stimuli are precisely aligned. The differential latency model suggests that the flash-lag effect occurs because the flash is processed slower than the moving object. Ac- cordingly it should be predicted that using another visual event with shorter/longer perceptual latency to replace the flash could induce a smaller/larger illu- sory lag. Three experiments were conducted to test this prediction utilizing onset/offset instead of flash in the classical flash-lag paradigm. The results indi- cated that the onset-lag was significantly larger than the flash-lag and the offset-lag, though the perceptual latency of onset was shorter than offset in the subjec- tive simultaneity judgment. The findings were incon- sistent with the prediction of the differential latency model, or of other models which suggest that the flash-lag effect reflects the perceptual mechanism of compensating perceptual latency.