Chica Ana B, Lupiáñez Juan
Departamento de Psicología Experimental y Fisiología del Comportamiento, Facultad de Psicología, Universidad de Granada, Campus Universitario de Cartuja, Granada, Spain.
Brain Res. 2009 Jun 30;1278:75-85. doi: 10.1016/j.brainres.2009.04.011. Epub 2009 Apr 15.
We investigate early (P1) and late (P3) modulations of event-related potentials produced by endogenous (expected vs. unexpected location trials) and exogenous (cued vs. uncued location trials) orienting of spatial attention. A 75% informative peripheral cue was presented 1000 ms before the target in order to study Inhibition of Return (IOR), a mechanism that produces slower responses to peripherally cued versus uncued locations. Endogenous attention produced its effects more strongly at later stages of processing, while IOR (an index of exogenous orienting) was found to modulate both early and late stages of processing. The amplitude of P1 was reduced for cued versus uncued location trials, even when endogenous attention was maintained at the cued location. This result indicates that the perceptual effects of IOR are not eliminated by endogenous attention, suggesting that the IOR mechanism produces a perceptual decrement on the processing of stimuli at the cued location that cannot be counteracted by endogenous attention.
我们研究了由内源性（预期位置试验与非预期位置试验）和外源性（线索提示位置试验与无线索提示位置试验）空间注意定向所产生的事件相关电位的早期（P1）和晚期（P3）调制。在目标出现前1000毫秒呈现一个75%信息性的外周线索，以研究返回抑制（IOR），这是一种对有外周线索提示的位置与无线索提示的位置产生较慢反应的机制。内源性注意在加工的后期阶段产生更强的效应，而IOR（外源性定向的一个指标）被发现对加工的早期和晚期阶段均有调制作用。对于有线索提示与无线索提示的位置试验，即使内源性注意保持在有线索提示的位置，P1的波幅也会降低。这一结果表明，IOR的知觉效应不会被内源性注意消除，提示IOR机制对有线索提示位置的刺激加工产生了一种知觉衰减，而这种衰减不能被内源性注意抵消。
