Abstract:
Grid-cells firing fields tile the environment with a 6-fold periodicity during both locomotion and visual exploration. Here, we tested, in humans, whether movements of covert attention elicit grid-like coding using frequency tagging. Participants observed visual trajectories presented sequentially at fixed rate, allowing different spatial periodicities (e.g., 4-, 6-, and 8-fold) to have corresponding temporal periodicities (e.g., 1, 1.5, and 2 Hz), thus resulting in distinct spectral responses. We found a higher response for the (grid-like) 6-fold periodicity and localized this effect in medial-temporal sources. In a control experiment featuring the same temporal periodicity but lacking spatial structure, the 6-fold effect did not emerge, suggesting its dependency on spatial movements of attention. We report evidence that grid-like signals in the human medial-temporal lobe can be elicited by covert attentional movements and suggest that attentional coding may provide a suitable mechanism to support the activation of cognitive maps during conceptual navigation.
摘要:
在运动和视觉探索过程中,网格单元点火场都以6倍的周期性平铺环境。这里,我们测试过,在人类中,隐性注意力的运动是否会引起使用频率标记的网格状编码。参与者观察到以固定速率顺序呈现的视觉轨迹,允许不同的空间周期性(例如,4-,6-,和8倍)以具有相应的时间周期性(例如,1、1.5和2Hz),从而导致不同的光谱响应。我们发现(网格状)6倍周期性的响应较高,并将这种影响定位在内侧时间源中。在具有相同时间周期但缺乏空间结构的对照实验中,6倍效应没有出现,表明它依赖于注意力的空间运动。我们报告了证据表明,隐蔽的注意力运动可以引起人类内侧颞叶中的网格状信号,并建议注意力编码可以提供一种合适的机制来支持概念导航过程中认知图的激活。