Department of Psychology, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada.
J Exp Psychol Hum Percept Perform. 2013 Jun;39(3):849-60. doi: 10.1037/a0030510. Epub 2012 Nov 19.
The presence of a salient distractor interferes with visual search. According to the salience-driven selection hypothesis, this interference is because of an initial deployment of attention to the distractor. Three event-related potential (ERP) findings have been regarded as evidence for this hypothesis: (a) salient distractors were found to elicit an ERP component called N2pc, which reflects attentional selection; (b) with target and distractor on opposite sides, a distractor N2pc was reported to precede the target N2pc (N2pc flip); (c) the distractor N2pc on slow-response trials was reported to occur particularly early, suggesting that the fastest shifts of attention were driven by salience. This evidence is equivocal, however, because the ERPs were noisy (b, c) and were averaged across all trials, thereby making it difficult to know whether attention was deployed directly to the target on some trials (a, b). We reevaluated this evidence using a larger sample size to reduce noise and by analyzing ERPs separately for fast- and slow-response trials. On fast-response trials, the distractor elicited a contralateral positivity (PD)-an index of attentional suppression-instead of an N2pc. There was no N2pc flip or early distractor N2pc. As it stands, then, there is no ERP evidence for the salience-driven selection hypothesis.
显著的分心物的存在会干扰视觉搜索。根据突显驱动选择假说，这种干扰是由于注意力最初被吸引到分心物上。三个事件相关电位 (ERP) 发现被认为是该假说的证据：(a) 显著的分心物会引起称为 N2pc 的 ERP 成分，反映了注意力的选择；(b) 在目标和分心物在相对的两侧时，报告了分心物 N2pc 先于目标 N2pc（N2pc 翻转）；(c) 在慢反应试验中，分心物 N2pc 被报告特别早发生，表明最快的注意力转移是由突显驱动的。然而，这种证据是模棱两可的，因为 ERP 是嘈杂的（b，c），并且是在所有试验上平均的，因此很难知道在某些试验上注意力是否直接被分配到目标上（a，b）。我们使用更大的样本量来减少噪声，并分别分析快反应和慢反应试验的 ERP，重新评估了这一证据。在快反应试验中，分心物引起了对侧正性（PD）-注意力抑制的指标-而不是 N2pc。没有 N2pc 翻转或早期分心物 N2pc。因此，目前没有 ERP 证据表明突显驱动的选择假说。
