Multiple mechanisms of selective attention: differential modulation of stimulus processing by attention to space or time
Multiple mechanisms of selective attention: differential modulation of stimulus processing by attention to space or time
复制标题
DOI：
10.1016/s0028-3932(02)00087-8
复制
发表时间：
2002-01-01
期刊：
影响因子：
2.6
通讯作者：
Nobre, AC
中科院分区：
文献类型：
--
作者：
Griffin, IC;Miniussi, C;Nobre, AC
两项研究利用事件相关电位（ERPs）比较了空间位置和时间间隔对注意力定向的调节作用。在两个实验中，受试者都执行注意定向任务，在空间定向和时间定向条件下使用相同的刺激。第一个实验（N = 16）采用双侧外周靶标（偏心率7.5度），在两个不同的时间间隔（提示开始后600、1200 ms）。在空间定向过程中，一个象征性的中央线索（75%的概率）预测了相关目标的空间位置（左，右）。没有给出可能的目标间隔（短或长）的信息。在时间定向中，线索预测的是目标间隔，而不是目标位置。有效提示在空间和时间定向条件下均显著缩短反应时间。对相同的非目标刺激阵列的erp进行分析，以分离内源性注意机制。空间注意和时间注意对刺激加工具有明显的调节作用。集中的空间注意影响早期视觉分量的振幅。时间注意的调节开始较晚，主要影响与决策和反应相关的电位。第二个实验（N = 12）采用单侧目标刺激，并将刺激在短时间间隔和长时间间隔以及左注视或右注视时出现的概率相等。结果证实了空间取向和时间取向对刺激加工的不同调节模式。注意行为的优化因此可以作为不同调节过程的结果来实现，这说明了人类大脑中注意功能的灵活性。
Two studies compared the modulatory effects of orienting attention to spatial locations versus temporal intervals using event-related potentials (ERPs). In both experiments subjects performed attentional orienting tasks, which used identical stimuli in both spatial and temporal orienting conditions. The first experiment (N = 16) used bilateral peripheral targets (7.5degrees eccentricity) at two different time intervals (600, 1200 ms after cue onset). During spatial orienting a symbolic central cue predicted (75% probability) the spatial location (left, right) of the relevant target. No information was given about the probable target interval (short, long). In temporal orienting the cue predicted the target interval but not its location. Valid cueing produced significantly shorter reaction times in both the spatial and temporal orienting conditions. ERPs to identical, non-target stimulus arrays were analysed, to isolate endogenous attentional mechanisms. Spatial and temporal attention had distinct modulatory effects upon stimulus processing. Focused spatial attention affected the amplitude of early visual components. Modulation by temporal attention started later, and mainly affected potentials linked to decisions and responses. The second experiment (N = 12) used unilateral target stimuli, and equated the probability of stimulus occurrence at short and long time intervals and at left or fight of fixation. The results confirmed the distinct pattern of modulation of stimulus processing by spatial and temporal orienting. The optimisation of behaviour by attention can thus be achieved as a consequence of distinct modulatory processes, illustrating the flexibility of attentional functions in the human brain.