Ruz María, Aranda Clara, Sarmiento Beatriz R, Sanabria Daniel
Department of Experimental Psychology, Mind, Brain and Behavior Research Center, Universidad de Granada, Campus de Cartuja s/n, 18071, Granada, Spain.
Exp Brain Res. 2015 May;233(5):1491-502. doi: 10.1007/s00221-015-4223-y. Epub 2015 Feb 18.
The ability of attention to apply in a flexible manner to several types of information at various stages of processing has been studied extensively. However, the susceptibility of these effects to the nature of the idiosyncratic items being attended is less understood. In the current study, we used symbolic cues to orient the attention of participants to the subsequent appearance of the face of a famous person (the former king of Spain) or an unfamiliar face. These were matched in perceptual characteristics. Behavioral effects showed that face-specific attention optimized response speed in an orthogonal task when the target matched the cue (valid trials) compared to when it did not (invalid trials). According to topographical analyses of the electrophysiological data, the famous and unfamiliar faces engaged dissociable brain circuits in two different temporal windows, from 144 to 300 ms after target processing, and at a later 456-492 ms epoch. In addition, orienting attention to specific faces modulated the perceptual stages reflected in the P1 and N170 potentials but with a different laterality pattern that depended on the familiarity of the faces. Whereas only attention to the famous face enhanced the P1 potential at left posterior electrodes, with no corresponding effect for the unfamiliar face at this stage, the N170 was modulated at left posterior sites for the famous item and at right homologous electrodes for the unfamiliar face. Intermediate processing stages, previously linked to facial identity processing indexed by the P2 and N2 potentials, reflected item familiarity but were not affected by the cueing manipulation. At the P3 level, attention influenced again item processing but did so in an equivalent manner for the famous and unfamiliar face. Our results, showing that identity-specific attention modulates perceptual stages of facial processing at different locations depending on idiosyncratic stimulus familiarity, may inform comparison of studies employing items with different degrees of novelty.
注意力在处理的各个阶段以灵活方式应用于几种类型信息的能力已得到广泛研究。然而，这些效应对于所关注的特质性项目性质的敏感性却鲜为人知。在当前研究中，我们使用符号线索将参与者的注意力导向一位名人（西班牙前国王）或一张陌生面孔随后的出现。这些面孔在感知特征上相互匹配。行为效应表明，与目标不匹配线索时（无效试验）相比，当目标与线索匹配时（有效试验），特定面孔的注意力在正交任务中优化了反应速度。根据电生理数据的地形分析，著名面孔和陌生面孔在两个不同的时间窗口激活了可分离的脑回路，一个是在目标处理后144至300毫秒，另一个是在稍后的456 - 492毫秒时段。此外，将注意力导向特定面孔调节了P1和N170电位所反映的感知阶段，但具有不同的偏侧性模式，这取决于面孔的熟悉程度。仅对著名面孔的注意力增强了左后电极处的P1电位，在此阶段陌生面孔没有相应效果，而N170在著名面孔的左后部位以及陌生面孔的右同源电极处受到调节。先前与由P2和N2电位索引的面部身份处理相关联的中间处理阶段反映了项目熟悉度，但不受线索操纵的影响。在P3水平，注意力再次影响项目处理，但对著名面孔和陌生面孔的影响方式相同。我们的结果表明，特定身份的注意力根据特质性刺激的熟悉程度在不同位置调节面部处理的感知阶段，这可能为比较采用不同新颖程度项目的研究提供参考。
