Attention Reorients Periodically.
Attention Reorients Periodically.
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DOI：
10.1016/j.cub.2016.04.046
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发表时间：
2016-06-20
期刊：
影响因子：
--
通讯作者：
Carrasco M
中科院分区：
文献类型：
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作者：
Dugué L;Roberts M;Carrasco M
自主注意的重新定向使得在先前无人注意的位置处理刺激成为可能。虽然研究已经确定了一个腹侧额顶叶网络的注意，很少有人知道是否和如何早期视觉区参与非自愿的，甚至在自愿重新定向，其时间动态是未知的。我们使用经颅磁刺激（TMS）在枕叶皮层干扰注意力重定向，并研究其在这一过程中的作用和时间动力学。人类观察员进行了方向辨别任务，有效或无效的注意提示，在一系列的刺激对比。有效的提示诱导的行为反应增益增加，更高的渐近性能比无人值守的位置。在随后的TMS会话中，观察者执行相同的任务，具有高刺激对比度。基于光幻视映射，TMS双脉冲在不同的延迟之一施加到视网膜定位区（V1/V2）的一致的大脑位置，对应于目标或分心物的诱发信号，在有效或无效的试验。因此，刺激是相同的四个实验条件（有效/无效的线索条件×目标/分心刺激）。目标和干扰物的TMS调制都是周期性的（5 Hz，θ），并且仅在无效试验中彼此异相，此时注意力必须从干扰物中脱离并重新定向到目标位置。自主注意力的重新定向周期性地涉及θ频率的V1/V2。这些结果表明，经颅磁刺激探头θ相位复位的注意力重定向，并帮助链接周期性采样的时间和注意力重定向的空间。
Reorienting of voluntary attention enables the processing of stimuli at previously unattended locations. Although studies have identified a ventral fronto-parietal network underlying attention, little is known about whether and how early visual areas are involved in involuntary and even less in voluntary reorienting, and their temporal dynamics are unknown. We used transcranial magnetic stimulation (TMS) over the occipital cortex to interfere with attentional reorienting and study its role and temporal dynamics in this process. Human observers performed an orientation discrimination task, with either valid or invalid attention cueing, across a range of stimulus contrasts. Valid cueing induced a behavioral response gain increase, higher asymptotic performance for attended than unattended locations. During subsequent TMS sessions, observers performed the same task, with high stimulus contrast. Based on phosphene mapping, TMS double pulses were applied at one of various delays to a consistent brain location in retinotopic areas (V1/V2), corresponding to the evoked signal of the target or distractor, in a valid or invalid trial. Thus, the stimulation was identical for the four experimental conditions (valid/invalid cue condition × target/distractor-stimulated). TMS modulation of the target and distractor were both periodic (5 Hz, theta) and out of phase with respect to each other in invalid trials only, when attention had to be disengaged from the distractor and reoriented to the target location. Reorientation of voluntary attention periodically involves V1/V2 at the theta frequency. These results suggest that TMS probes theta phase-reset by attentional reorienting and help link periodic sampling in time and attention reorienting in space.