Yoshimoto Sanae, Takeuchi Tatsuto
Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, Japan.
Department of Psychology, Japan Women's University, Kanagawa, Japan.
J Vis. 2019 Apr 1;19(4):4. doi: 10.1167/19.4.4.
We almost never experience visual instability, despite retinal image instability induced by eye movements. How the stability of visual perception is maintained through spatiotopic representation remains a matter of debate. The discrepancies observed in the findings of existing neuroscience studies regarding spatiotopic representation partly originate from differences in regard to how attention is deployed to stimuli. In this study, we psychophysically examined whether spatial attention is needed to perceive spatiotopic visual motion. For this purpose, we used visual motion priming, which is a phenomenon in which a preceding priming stimulus modulates the perceived moving direction of an ambiguous test stimulus, such as a drifting grating that phase shifts by 180°. To examine the priming effect in different coordinates, participants performed a saccade soon after the offset of a primer. The participants were tasked with judging the direction of a subsequently presented test stimulus. To control the effect of spatial attention, the participants were asked to conduct a concurrent dot contrast-change detection task after the saccade. Positive priming was prominent in spatiotopic conditions, whereas negative priming was dominant in retinotopic conditions. At least a 600-ms interval between the priming and test stimuli was needed to observe positive priming in spatiotopic coordinates. When spatial attention was directed away from the location of the test stimulus, spatiotopic positive motion priming completely disappeared; meanwhile, the spatiotopic positive motion priming at shorter interstimulus intervals was enhanced when spatial attention was directed to the location of the test stimulus. These results provide evidence that an attentional resource is requisite for developing spatiotopic representation more quickly.
尽管眼球运动引起视网膜图像不稳定，但我们几乎从未体验到视觉不稳定。视觉感知的稳定性如何通过空间拓扑表征得以维持仍是一个有争议的问题。现有神经科学研究在空间拓扑表征的研究结果中观察到的差异，部分源于对刺激注意力分配方式的不同。在本研究中，我们通过心理物理学方法研究了感知空间拓扑视觉运动是否需要空间注意力。为此，我们使用了视觉运动启动，这是一种先前的启动刺激会调节模糊测试刺激（如相位偏移180°的漂移光栅）的感知运动方向的现象。为了在不同坐标中检查启动效应，参与者在启动刺激消失后不久进行一次扫视。参与者的任务是判断随后呈现的测试刺激的方向。为了控制空间注意力的影响，要求参与者在扫视后进行同时的点对比度变化检测任务。正向启动在空间拓扑条件下很突出，而负向启动在视网膜拓扑条件下占主导。在空间拓扑坐标中观察到正向启动至少需要启动刺激和测试刺激之间有600毫秒的间隔。当空间注意力从测试刺激的位置转移开时，空间拓扑正向运动启动完全消失；与此同时，当空间注意力指向测试刺激的位置时，较短刺激间隔下的空间拓扑正向运动启动会增强。这些结果提供了证据，表明注意力资源对于更快地形成空间拓扑表征是必要的。
