Akselrod Michel, Herzog Michael H, Öğmen Haluk
1] Laboratory of Perceptual and Cognitive Dynamics, Center for Neuro-Engineering and Cognitive Science, Department of Electrical &Computer Engineering, University of Houston, USA [2] Laboratory of Psychophysics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland.
Laboratory of Psychophysics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland.
Sci Rep. 2014 Aug 14;4:6063. doi: 10.1038/srep06063.
Vision is a constructive process. For example, a square, flashed at two distinct locations one after the other, appears to move smoothly between the two locations rather than as two separate flashes (apparent motion). Apparent motion is usually perceived along the shortest path between locations. Previous studies have shown that retinotopic activity in V1 correlates well with the subjective filling-in in apparent motion. If V1 activity truly reflects illusory motion, it should flexibly reflect filling-in of any path, subjectively perceived. Here, we used a path-guided apparent motion paradigm in which a faint cue, presented in addition to the squares, leads to a curved illusory motion path. We found retinotopic activity in V1 to reflect the illusory filling-in of the curved path, similarly to filling-in with linear, shortest paths. Moreover, our results show that activity along the linear path was less selective to stimulus conditions than the activity along the curved path. This finding may be interpreted as V1 activity representing a small subset of infinitely many possible solutions to ambiguous stimuli, whilst giving more weight to the shortest path/energy solution.
视觉是一个建构过程。例如，一个正方形先后在两个不同位置闪现时，看起来是在这两个位置之间平滑移动，而不是两次分开的闪现（似动现象）。似动现象通常沿着位置之间的最短路径被感知到。先前的研究表明，V1区的视网膜拓扑活动与似动现象中的主观填充密切相关。如果V1区的活动真的反映了虚幻运动，那么它应该能灵活地反映任何主观感知到的路径的填充。在这里，我们使用了一种路径引导的似动范式，其中除了正方形之外还呈现一个微弱的提示，从而导致一条弯曲的虚幻运动路径。我们发现V1区的视网膜拓扑活动反映了弯曲路径的虚幻填充，类似于线性最短路径的填充。此外，我们的结果表明，沿着线性路径的活动对刺激条件的选择性不如沿着弯曲路径的活动。这一发现可以解释为，V1区的活动代表了对模糊刺激的无限多种可能解决方案中的一小部分，同时更重视最短路径/能量解决方案。
