Tracking the Timecourse of Social Perception: The Effects of Racial Cues on Event-Related Brain Potentials

Abstract

Event-related potentials were used to track social perception processes associated with viewing faces of racial ingroup and outgroup members. Activity associated with three distinct processes was detected. First, peaking at approximately 170 ms, faces were distinguished from nonface stimuli. Second, peaking at approximately 250 ms, ingroup members were differentiated from outgroup members, with a larger component suggesting greater attention to ingroup members. This effect may reflect the spontaneous application of a deeper level of processing to ingroup members. Third, peaking at approximately 520 ms, evaluative differentiation of ingroup and outgroup members occurred, with greater ingroup bias displayed by those with higher levels of prejudice on an explicit measure. Together, the results demonstrate the promise of using neural processes to track the presence, timing, and degree of activation of components relevant to social perception, prejudice, and stereotyping.

Multiple cues in social perception: The time course of processing race and facial expression

“…N200 amplitude-As with the P200, past race and emotion effects were both replicated in the N200 (see Figure 1, Figure 2, & Table 3). For race, the main effect replicated past findings (Ito & Urland, 2003,2005Ito et al, 2004) by showing larger (more negative) N200s to White than Black faces (M=−.51 μV and M=1.87 μV, respectively, F(1,28)=64.89, p<.01). The main effect of emotion was also significant (F(2,56)=10.92, p<.01).…”

“…In the case of expression and race, although automatic vigilance mechanisms make it adaptive to initially devote greater attentional resources to angry faces and faces of racial outgroup members (as reflected in the N100 and P200), individuals with positive or neutral expressions, and those who are racial ingroup members are probably more desirable for greater individuation. Consequently, this component is typically larger to neutral than fearful faces (Eimer & Holmes, 2002;Holmes, Vuilleumeir, & Eimer, 2003) and to faces of one's own race than other races (Ito, Thompson, & Cacioppo, 2004;Ito & Urland, 2003;James, Johnstone, & Hayward, 2001;Tanaka, Kiefer, & Bukach, 2004;Walker & Tanaka, 2003). For the N200, individuation and deeper processing predict larger N200s to faces displaying happy, approachable expressions and to Whites (cf., Holmes et al, 2003;Ito & Urland, 2003;James et al, 2001;Tanaka et al, 2004;Walker & Tanaka, 2003).…”

Neural repetition suppression to identity is abolished by other-race faces

“…Several studies have failed to show any sensitivity to race on the N170 (6,7,14), or on its frontal counterpart, the vertex positive potential (11). These results suggest that brain activity in the N170 time window codes only for the detection of a face shape, whereas race information from faces is extracted in postperceptual stages occurring roughly between 250 and 300 ms after stimulus onset (6,7,14).…”

“…The N170 is a bilateral occipito-temporal negative deflection peaking roughly 170 ms after stimulus onset, larger for faces compared with other visual categories. Activity in this time window is associated with the early accumulation of perceptual information leading to visual categorization, which is necessary for postsensory, decision, and motor stages (27,28).Numerous electrophysiological studies have investigated the early electrophysiological dynamics of the ORE (6,7,(10)(11)(12)(13)(14)(15). Several studies have failed to show any sensitivity to race on the N170 (6,7,14), or on its frontal counterpart, the vertex positive potential (11).…”

“…Numerous electrophysiological studies have investigated the early electrophysiological dynamics of the ORE (6,7,(10)(11)(12)(13)(14)(15). Several studies have failed to show any sensitivity to race on the N170 (6,7,14), or on its frontal counterpart, the vertex positive potential (11).…”