Unveiling the time course of visual stabilization through human electrophysiology

Positions of objects are coded relative to their surroundings, presumably providing visual stability even when we move our eyes around a visual scene. But when does this perceived stability of objects arise? Here we use a visual illusion, the frame-induced position shift, and measure electrophysiological activity elicited by an object whose perceived position is either shifted due to a surrounding frame or not, thus dissociating perceived and physical locations. We found that early visually-evoked responses were sensitive to physical location information earlier in time (~70ms) than perceived location information (~140ms). Furthermore, we show that location information can be reliably decoded across physical and perceived locations during the later time interval (140-180ms) but not during the earlier time interval (70-110ms). Together these results suggest that visual stability of objects emerges relatively late and is thus dependent on recurrent feedback from higher processing stages.

物体相对于其周围环境的定位信息被编码，据此推测，即便在视觉场景中眼球移动时，也能维持视觉的稳定性。然而，物体感知的这种稳定性究竟在何时产生？本研究采用了一种视觉错觉——框架诱导的位置偏移，并测量由物体引发的电生理活动，该物体的感知位置或因周围框架而偏移，或未发生偏移，从而将感知位置与物理位置分离。研究发现，早期视觉诱发反应对物理位置信息的敏感性早于感知位置信息（约70毫秒）。此外，我们还发现，在较晚的时间间隔（140-180毫秒）内，可以可靠地解码物理位置与感知位置的信息，而在较早的时间间隔（70-110毫秒）内则不能。综合这些结果，表明物体视觉稳定性出现相对较晚，因而依赖于更高处理阶段的反复反馈。