Itier Roxane J, Taylor Margot J
CerCo-CNRS, Université Paul Sabatier, 31062 Toulouse, France.
Neuroimage. 2002 Feb;15(2):353-72. doi: 10.1006/nimg.2001.0982.
Using ERPs in a face recognition task, we investigated whether inversion and contrast reversal, which seem to disrupt different aspects of face configuration, differentially affected encoding and memory for faces. Upright, inverted, and negative (contrast-reversed) unknown faces were either immediately repeated (0-lag) or repeated after 1 intervening face (1-lag). The encoding condition (new) consisted of the first presentation of items correctly recognized in the two repeated conditions. 0-lag faces were recognized better and faster than 1-lag faces. Inverted and negative pictures elicited longer reaction times, lower hit rates, and higher false alarm rates than upright faces. ERP analyses revealed that negative and inverted faces affected both early (encoding) and late (recognition) stages of face processing. Early components (N170, VPP) were delayed and enhanced by both inversion and contrast reversal which also affected P1 and P2 components. Amplitudes were higher for inverted faces at frontal and parietal sites from 350 to 600 ms. Priming effects were seen at encoding stages, revealed by shorter latencies and smaller amplitudes of N170 for repeated stimuli, which did not differ depending on face type. Repeated faces yielded more positive amplitudes than new faces from 250 to 450 ms frontally and from 400 to 600 ms parietally. However, ERP differences revealed that the magnitude of this repetition effect was smaller for negative and inverted than upright faces at 0-lag but not at 1-lag condition. Thus, face encoding and recognition processes were affected by inversion and contrast-reversal differently.
在一项人脸识别任务中使用事件相关电位（ERPs），我们研究了倒置和对比度反转（这似乎会破坏面部构型的不同方面）是否对面部的编码和记忆产生不同影响。正立、倒置和负像（对比度反转）的陌生面孔要么立即重复呈现（0延迟），要么在中间间隔一张面孔后重复呈现（1延迟）。编码条件（新面孔）包括在两个重复条件下首次正确识别的项目呈现。0延迟的面孔比1延迟的面孔识别得更好、更快。与正立面孔相比，倒置和负像图片引发的反应时间更长、命中率更低、误报率更高。ERP分析表明，负像和倒置面孔会影响面部处理的早期（编码）和晚期（识别）阶段。早期成分（N170、VPP）在倒置和对比度反转时均延迟且增强，这也影响了P1和P2成分。在350至600毫秒时，倒置面孔在额叶和顶叶部位的波幅更高。在编码阶段可以看到启动效应，表现为重复刺激时N170的潜伏期更短、波幅更小，且启动效应不依赖于面孔类型。在额叶250至450毫秒以及顶叶400至600毫秒时，重复面孔比新面孔产生的波幅更正。然而，ERP差异显示，在0延迟条件下，负像和倒置面孔的这种重复效应幅度比正立面孔小，但在1延迟条件下并非如此。因此，面部编码和识别过程受倒置和对比度反转的影响不同。
