Three experiments investigated the influence of unperceived events on response activation. Masked primers were presented before a target. On compatible trials, primes and targets were identical; on incompatible trials, opposite responses were assigned to them. Forced-choice performance indicated that prime identification was prevented by the masking procedure, but overt performance and motor activation as mirrored by the lateralized readiness potential (LRP) were systematically influenced by the prime. The direction of these effects was unexpected: Performance costs for compatible and performance benefits for incompatible trials were obtained relative to a neutral trial condition. The LRP revealed a sequential pattern of motor activation. A partial activation of the response corresponding to the prime was followed by a reverse activation pattern. It is argued that these effects primarily reflect an inhibition of the response initially triggered by the prime.

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Using event-related brain potentials (ERPs), we investigated the time course of facial expression processing in human subjects watching photographs of fearful and neutral faces. Upright fearful faces elicited a frontocentral positivity within120 ms after stimulus presentation, which was followed by a broadly distributed sustained positivity beyond 250 ms post-stimulus. Emotional expression e¡ects were delayed and attenuated when faces were inverted. In contrast, the face-speci¢c N170 component was completely una¡ected by facial expression.We conclude that emotional expression analysis and the structural encoding of faces are parallel processes. Early emotional ERP modulations may re£ect the rapid activation of prefrontal areas involved in the analysis of facial expression. NeuroReport 13:1^5

To investigate which stages in the structural encoding of faces are reflected by the face-specific N170 component, ERPs (event-related brain potentials) were recorded in response to different types of face and non-face stimuli. The N170 was strongly attenuated for cheek and back views of faces relative to front and profile views, demonstrating that it is not merely triggered by head detection. Attenuated and delayed N170 components were elicited for faces lacking internal features as well as for faces without external features, suggesting that it is not exclusively sensitive to salient internal features. It is suggested that the N170 is linked to late stages of structural encoding, where representations of global face configurations are generated in order to be utilised by subsequent face recognition processes.