Spatial attention freezes during the attention blink
Spatial attention freezes during the attention blink
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DOI：
10.1111/j.1469-8986.2006.00411.x
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发表时间：
2006-07-01
期刊：
影响因子：
3.7
通讯作者：
Robitaille, N.
中科院分区：
文献类型：
--
作者：
Dell'Acqua, R.;Sessa, P.;Robitaille, N.
采用快速连续视觉呈现范式的一种变体，在注视点的左侧和右侧依次显示两个横向刺激序列，嵌入两对目标刺激T1和T2。T1由一对字母数字字符组成，受试者要么忽略T1，要么对T1进行编码以获得延迟反应。T2是一个预设颜色的侧面正方形。正方形的一边有一个小缺口，这个刺激的任务是报告哪一边有缺口。当受试者被要求忽略T1时，T2锁定的ERP产生了明显的N2pc，即T2占据位置对侧电极位置的负性更强。N2pc之后是持续的后对侧阴性（SPCN）。当被试被要求监测T1和T2时，N2pc和SPCN分量的振幅都依赖于与T1相关的任务的难度。如果T1由必须编码的数字组成，以进行延迟的相同/不同判断，则N2pc和SPCN组件都被完全抑制。虽然减弱了，但当T1由一对被试可以忽略的符号组成时，这些成分仍然存在。结果表明，N2pc在空间领域的注意力分配机制受到将信息编码为视觉短期记忆所需的并发认知操作的显著干扰。
A variant of the rapid serial visual presentation paradigm was used to display sequentially two lateral sequences of stimuli, one to the left and one to the right of fixation, embedding two pairs of target stimuli, T1 and T2. T1 was composed of a pair of alphanumeric characters, and subjects had either to ignore T1 or to encode T1 for a delayed response. T2 was a lateral square of a prespecified color. The square had a small gap in one side, and the task for this stimulus was to report which side had the gap. When subjects were required to ignore T1, the T2-locked ERP produced a clear N2pc, that is, a greater negativity at electrode sites contralateral to the position occupied by T2. This N2pc was followed by a sustained posterior contralateral negativity (SPCN). When subjects were required to monitor T1 in addition to T2, both the N2pc and the SPCN components amplitude depended on the difficulty of the task associated with T1. If T1 was composed of digits that had to be encoded for a delayed same/different judgment, both the N2pc and the SPCN components were entirely suppressed. Although attenuated, such components were present when T1 was composed of a pair of symbols that subjects could disregard. The results suggest that a set of mechanisms subserving the allocation of attention in the spatial domain, resulting in the N2pc, suffer significant interference from concurrent cognitive operations required to encode information into visual short-term memory.