ANGRY FACES AND THE ATTENTIONAL BLINK 1349 that this attentional effect extends to the processing of angry facial expressions, but also that it can be found for schematic faces, which have been proposed to provide a relatively pure representation of key features of emotional faces (Fox et al., 2000; Juth et al., 2005; O¨ hman et al., 2001). Indeed, as noted in the latter studies, a further advantage of schematic faces is that they allow the investigation of processing biases for emotional stimuli while controlling for potential confounds that are more difficult to control when using real-life faces (e.g., variation in physical features such as contrast, luminance, etc.; see O¨ hman et al., 2001, for further discussion of this issue). Thus, the current findings further suggest that the processing advantage observed for threatening faces in AB studies is due to the emotional meaning of the stimuli rather than image artefacts. However, the use of schematic faces is not without potential limitations, as, for example, there are few exemplars (e.g., only one angry face used here) and Horstmann, Borgstedt, and Heumann (2006) have suggested that both emotional and perceptual variables could contribute to their effects. Thus, it seems essential for research to evaluate converging lines of evidence from studies using varied types of stimuli, including real-life and schematic representations of pictorial threat, as each methodology has its own advantages and disadvantages. It would also seem helpful to clarify whether certain features of facial expressions associated with anger (e.g., shape of eyebrows or mouth) are more readily identified in RSVP streams than those associated with neutral or positive expressions (Lundqvist & O¨ hman, 2005). The present results indicated that the AB was reduced by threat faces, relative to neutral faces (at lags 2 and 3) and that this effect was not explained by a difference in the discriminability of these stimuli, given that no difference was found between the threat and neutral face types on single- target trials. The AB was also reduced by positive faces, relative to neutral faces (at lag 2), which is not easily explained by differences in stimulus discriminability, as there was no evidence from single-target trials to suggest that positive faces were easier to identify (indeed, the opposite was found, i.e., poorer identification of positive than neutral faces when presented alone in the RSVP stream). However, the finding of a larger AB for positive faces, relative to threat faces, is not entirely conclusive, given that positive faces were also harder to identify than threat faces on single-target trials. One important line for future research would be to investigate further the relative influences of stimulus valence and stimulus arousal on attention. The positive face stimulus used in the present study was selected by O¨ hman et al. (2001) to be the antithesis of the threatening (angry) face. Consequently, it was designed to be low on stimulus dimensions that are likely to be associated with arousal, including activity and potency (Lundqvist & O¨ hman, 2005). Thus, the positive-face stimulus may have differed from the threat and neutral faces not only in terms of emotional valence, but also in