Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Brain Res. 2010 Jul 23;1345:164-75. doi: 10.1016/j.brainres.2010.05.047. Epub 2010 May 24.
Attention is controlled by the interplay of sensory input and top-down processes. We compared attentional control processes during task switching and reorientation after distraction. The primary task was to discriminate laterally and centrally presented tones; these stimuli were composed of a frequent standard or an infrequent deviant pitch. In the distraction condition, pitch was irrelevant and could be ignored. In the switch condition, pitch changes were relevant: whenever a deviant tone was presented, participants had to discriminate its pitch and not its direction. The task in standard trials remained unchanged. In both conditions, deviants elicited mismatch negativity (MMN), P3a, P3b, and reorienting negativity (RON). We, therefore, suggest that distraction and switching are triggered by the same system of attentional control. In addition, remarkable differences were observable between the two conditions: In the switch condition the MMN was followed by a more pronounced N2b and P3a. The differences between these components support the idea that in the distraction condition, a switch of attention is only initiated but not completely performed.
注意受感觉输入和自上而下过程的相互作用控制。我们比较了在任务转换和分心后重新定向期间的注意力控制过程。主要任务是辨别侧向和中央呈现的音调；这些刺激由常见的标准音或罕见的偏差音组成。在分心条件下，音高是无关的，可以忽略不计。在转换条件下，音高变化是相关的：每当出现偏差音时，参与者必须辨别其音高而不是其方向。标准试验中的任务保持不变。在两种条件下，偏差都会引起失匹配负波（MMN）、P3a、P3b 和重新定向负波（RON）。因此，我们认为分心和转换是由相同的注意力控制系统触发的。此外，两种条件之间存在显著差异：在转换条件下，MMN 之后是更明显的 N2b 和 P3a。这些成分之间的差异支持这样一种观点，即在分心条件下，注意力的转换仅被启动但未完全执行。
