López-Moliner Joan, Linares Daniel
Grup Recerca Neurociència Cognitiva, Parc Científic-Universitat de Barcelona, Catalonia, Spain.
Vision Res. 2006 Jun;46(13):2122-9. doi: 10.1016/j.visres.2005.11.016. Epub 2006 Jan 6.
The flash-lag effect (FLE) is defined as an error in localization that consists of perceiving a flashed object to lag behind a moving one when both are presented in physical alignment. Previous studies have addressed the question if it is the predictability of the flash, or the moving object, that modulates the amount of the error. However, the case when the flash is self-generated, and hence can be internally predicted, has not yet been addressed. In Experiment 1, we compare four conditions: flash unpredictable, flash externally predicted by a beep, flash internally generated (and predicted) by pressing a key, and flash triggered by a key press but temporally unpredictable. The FLE was significantly reduced only when the flash was internally predictable. In Experiment 2, we rule out the possibility that the reduction of the FLE was due to the use of the key press as a temporal marker. We conclude that when the flash is perceived as a sensory consequence of our own action, its detection can be speeded up, thereby resulting in a reduction of the FLE. A third experiment supports this interpretation. The mechanism by virtue of which the detection is accelerated could be related to efferent signals from motor areas predicting the sensory consequences of our actions.
闪光滞后效应（FLE）被定义为一种定位误差，即当一个闪烁物体和一个移动物体在物理上对齐呈现时，会感觉到闪烁物体落后于移动物体。先前的研究探讨了是闪光的可预测性还是移动物体的可预测性调节了误差量这一问题。然而，闪光是自我产生因而可以在内部被预测的情况尚未得到探讨。在实验1中，我们比较了四种条件：闪光不可预测、闪光由蜂鸣声外部预测、闪光由按键内部产生（并预测）以及按键触发闪光但在时间上不可预测。只有当闪光在内部可预测时，闪光滞后效应才会显著降低。在实验2中，我们排除了闪光滞后效应降低是由于将按键用作时间标记的可能性。我们得出结论，当闪光被视为我们自身动作的感觉结果时，其检测可以加速，从而导致闪光滞后效应降低。第三个实验支持了这一解释。检测加速所凭借的机制可能与运动区域预测我们动作的感觉结果的传出信号有关。
