Nikolaev Andrey R, Meghanathan Radha Nila, van Leeuwen Cees
Laboratory for Perceptual Dynamics, Brain and Cognition Research Unit, KU Leuven - University of Leuven , Leuven , Belgium.
J Neurophysiol. 2018 Nov 1;120(5):2311-2324. doi: 10.1152/jn.00121.2018. Epub 2018 Aug 15.
In free viewing, the eyes return to previously visited locations rather frequently, even though the attentional and memory-related processes controlling eye-movement show a strong antirefixation bias. To overcome this bias, a special refixation triggering mechanism may have to be recruited. We probed the neural evidence for such a mechanism by combining eye tracking with EEG recording. A distinctive signal associated with refixation planning was observed in the EEG during the presaccadic interval: the presaccadic potential was reduced in amplitude before a refixation compared with normal fixations. The result offers direct evidence for a special refixation mechanism that operates in the saccade planning stage of eye movement control. Once the eyes have landed on the revisited location, acquisition of visual information proceeds indistinguishably from ordinary fixations. NEW & NOTEWORTHY A substantial proportion of eye fixations in human natural viewing behavior are revisits of recently visited locations, i.e., refixations. Our recently developed methods enabled us to study refixations in a free viewing visual search task, using combined eye movement and EEG recording. We identified in the EEG a distinctive refixation-related signal, signifying a control mechanism specific to refixations as opposed to ordinary eye fixations.
在自由观看时，眼睛会相当频繁地回到之前看过的位置，尽管控制眼球运动的注意力和记忆相关过程表现出强烈的反注视偏向。为了克服这种偏向，可能必须启用一种特殊的回视触发机制。我们通过将眼动追踪与脑电图记录相结合，探究了这种机制的神经学证据。在眼跳前的间隔期，脑电图中观察到了与回视计划相关的独特信号：与正常注视相比，回视前眼跳前电位的幅度降低。该结果为一种特殊的回视机制提供了直接证据，这种机制在眼球运动控制的扫视计划阶段起作用。一旦眼睛落在之前看过的位置，视觉信息的获取过程与普通注视并无区别。新内容与值得注意之处：人类自然观看行为中相当一部分的眼球注视是对最近看过位置的再次注视，即回视。我们最近开发的方法使我们能够在自由观看视觉搜索任务中研究回视，采用眼动和脑电图记录相结合的方式。我们在脑电图中识别出一种与回视相关的独特信号，这意味着存在一种特定于回视而非普通眼球注视的控制机制。
