Different scalp topography of brain potentials related to expression and identity matching of faces

Priming emotional facial expressions as evidenced by event-related brain potentials

“…Whereas in this study, contributions of differences in subjective probability could not be ruled out, the present results with equiprobable stimuli clearly support the view that the LPP modulations reflect priming of emotional expressions. Interestingly, the finding of an attenuated LPP following primed targets is at variance with most previous matching and repetition priming studies, which reported a reduced LPP in response to unprimed targets (e.g., Bobes et al, 2000;Schweinberger et al, 1995). This discrepancy may be due to the extremely short SOA applied here, which may have prevented the activation of a prime-related semantic context, held responsible for the LPP modulation in these other studies.…”

“…This effect also appears when semantically related faces are presented consecutively and is considered to result from a diminished superimposed N400 component when semantically related or identical faces follow each other. Similar results were reported by several studies employing matching tasks, in which participants compared two consecutive portraits with respect to congruence of facial expressions or identities (Bobes et al, 2000;Münte et al, 1998). Priming of stimuli which evoke similar affective attitudes has up to now only been demonstrated by behavioral studies showing that reaction times to words and pictures are shortened if their affective valence is primed by a preceding stimulus of similar valence (e.g.…”

Electrophysiological evidence for early non-conscious processing of fearful facial expressions

“…As noted above however, until only recently, emotional faces were not thought to affect earlier components, in particular the N170 (Munte et al, 1998;Bobes et al, 2000;Krolak-Salmon et al, 2001;Eimer and Holmes, 2002;Herrmann et al, 2002). This view is progressively being challenged and evidence favouring an N170 modulation now appears to be emerging.…”

“…Faces are generally claimed to give rise to a specific response, the N170 (e.g., see Bentin et al, 1996;Itier and Taylor, 2004) but it was previously thought that this response was insensitive to emotional expressions (Munte et al, 1998;Bobes et al, 2000;Krolak-Salmon et al, 2001;Eimer and Holmes, 2002;Herrmann et al, 2002; see also Eimer and Holmes, 2007;Vuilleumier and Pourtois, 2007 for recent reviews). Recently however, evidence has begun emerging that the N170 might nevertheless be modulated by emotional expression (Batty and Taylor, 2003;Miyoshi et al, 2004;Stekelenburg and de Gelder, 2004;Blau et al, 2007;Hendriks et al, 2007), although it is not known whether this modulation can be extended to non-conscious processing.…”

Event-Related Potentials in Response to Emotional Words in Patients with Major Depressive Disorder and Healthy Controls

“…The right-hemisphere (RH) dominance hypothesis postulates that the RH is responsible for processing all emotional information, regardless of valence (positive, negative or neutral) [11]. In contrast, the valence hypothesis states that the left hemisphere (LH) is specialized in the processing of positive emotional events that elicit appetitive or approach behaviors, whereas negative emotional information associated with withdrawal or defensive behaviors are processed primarily in the right prefrontal cortex [12].…”