Quenching of spontaneous fluctuations by attention in human visual cortex
Quenching of spontaneous fluctuations by attention in human visual cortex
复制标题
DOI：
10.1016/j.neuroimage.2017.12.089
复制
发表时间：
2018-05-01
期刊：
影响因子：
5.7
通讯作者：
Malach, Rafael
中科院分区：
文献类型：
--
作者：
Broday-Dvir, Rotem;Grossman, Shany;Malach, Rafael
在没有任务的情况下，人类大脑进入一种缓慢的自发波动模式。一个基本的、尚未解决的问题是，这些波动是否是持续的，因此在任务参与期间持续存在，或者被熄灭并被任务相关的激活所取代。在这里，我们研究了这个问题在人类视觉皮层，使用功能磁共振成像。参与者被要求执行随机出现的人脸和非人脸目标的识别任务（有人值守条件）或被动地观看它们（无人值守条件）。重要的是，在大约一半的试验中，所有的感官刺激都不存在。我们的研究结果表明，即使在没有刺激的情况下，自发波动被抑制的注意。这种效应发生在早期视觉皮层以及额顶叶注意网络区域。在无人值守的试验中，活动波动与瞳孔直径呈负相关，反对注意力波动作为影响的基础。结果表明，自发波动不保持不变的任务绩效，而是调制根据行为和认知需求。
In the absence of a task, the human brain enters a mode of slow spontaneous fluctuations. A fundamental, unresolved question is whether these fluctuations are ongoing and thus persist during task engagement, or alternatively, are quenched and replaced by task-related activations. Here, we examined this issue in the human visual cortex, using fMRI. Participants were asked to either perform a recognition task of randomly appearing face and non-face targets (attended condition) or watch them passively (unattended condition). Importantly, in approximately half of the trials, all sensory stimuli were absent. Our results show that even in the absence of stimuli, spontaneous fluctuations were suppressed by attention. The effect occurred in early visual cortex as well as in fronto-parietal attention network regions. During unattended trials, the activity fluctuations were negatively linked to pupil diameter, arguing against attentional fluctuations as underlying the effect. The results demonstrate that spontaneous fluctuations do not remain unchanged with task performance, but are rather modulated according to behavioral and cognitive demands.