Helen Keyes

Using a priming paradigm, we investigate whether socially important faces are processed preferentially compared to other familiar and unfamiliar faces, and whether any such effects are affected by changes in viewpoint. Participants were primed with frontal images of personally familiar, famous or unfamiliar faces, and responded to target images of congruent or incongruent identity, presented in frontal, three quarter or profile views. We report that participants responded significantly faster to socially important faces (a friend's face) compared to other highly familiar (famous) faces or unfamiliar faces. Crucially, responses to famous and unfamiliar faces did not differ. This suggests that, when presented in the context of a socially important stimulus, socially unimportant familiar faces (famous faces) are treated in a similar manner to unfamiliar faces. This effect was not tied to viewpoint, and priming did not affect socially important face processing differently to other faces.

We respond more quickly to our own face than to other faces, but there is debate over whether this is connected to attention-grabbing properties of the self-face. In two experiments, we investigate whether the self-face selectively captures attention, and the attentional conditions under which this might occur. In both experiments, we examined whether different types of face (self, friend, stranger) provide differential levels of distraction when processing self, friend and stranger names. In Experiment 1, an image of a distractor face appeared centrally – inside the focus of attention – behind a target name, with the faces either upright or inverted. In Experiment 2, distractor faces appeared peripherally – outside the focus of attention – in the left or right visual field, or bilaterally. In both experiments, self-name recognition was faster than other name recognition, suggesting a self-referential processing advantage. The presence of the self-face did not cause more distraction in the naming task compared to other types of face, either when presented inside (Experiment 1) or outside (Experiment 2) the focus of attention. Distractor faces had different effects across the two experiments: when presented inside the focus of attention (Experiment 1), self and friend images facilitated self and friend naming, respectively. This was not true for stranger stimuli, suggesting that faces must be robustly represented to facilitate name recognition. When presented outside the focus of attention (Experiment 2), no facilitation occurred. Instead, we report an interesting distraction effect caused by friend faces when processing strangers’ names. We interpret this as a “social importance” effect, whereby we may be tuned to pick out and pay attention to familiar friend faces in a crowd. We conclude that any speed of processing advantages observed in the self-face processing literature are not driven by automatic attention capture.

Categorical perception of robustly represented faces (self, friend) and unfamiliar faces is investigated, and the relative roles of configural and featural information are examined. Participants performed identification and discrimination tasks on morph series containing the self-face and a friend's face (self–Friend 1), two friends' faces (Friend 2–Friend 3), and two unfamiliar faces (Unfamiliar 1–Unfamiliar 2), presented in upright and inverted orientations. For upright faces, categorical perception effects were observed for both familiar morph series but not for the unfamiliar morph series, suggesting that robust representation is a requirement for categorical perception in facial identity. For inverted faces, categorical perception was observed for the self–Friend 1 morph series only. This suggests that categorical perception is tied to configural processing for familiar non-self-faces, but can be observed for self-faces during featural processing—consistent with evidence that self-face representations contain strong configural and featural components. Finally, categorical perception is not enhanced by the presence of the self-face relative to other familiar faces when upright, but shows a trend of being enhanced for self-faces when inverted, adding to the debate on the ways in which robustly represented faces can elicit categorical perception.

The neural basis of self-recognition is mainly studied using brain-imaging techniques which reveal much about the localization of self-processing in the brain. There are comparatively few studies using EEG which allow us to study the time course of self-recognition. In this study, participants monitored a sequence of images, including 20 distinct images of their own face, a friend’s face and a stranger’s face articulating different speech sounds, while EEG was recorded from 64 scalp electrodes. Differences in the ERP waveforms were observed very early on, with increased N170 and VPP amplitude to self relative to both friend and stranger measured over posterior and fronto-central sites, respectively. This ‘self effect’ was also marked at ∼250 ms where P2/N2 amplitude was significantly reduced for self-faces. By comparison, differences between friend and stranger faces did not emerge until 250 ms and beyond, where a more conventional ‘familiarity effect’ was observed. The data also point to a ‘less lateralized’ representation of self over posterior sites. These findings are consistent with both behavioral and fMRI studies which suggest that self-face processing is ‘special’ and are discussed with reference to EEG studies of face processing.

We examine interhemispheric cooperation in the recognition of personally known faces whose long-term familiarity ensures frequent co-activation of face-sensitive areas in the right and left brain. Images of self, friend, and stranger faces were presented for 150 ms in upright and inverted orientations both unilaterally, in the right or left visual field, and bilaterally. Consistent with previous research, we find a bilateral advantage for familiar but not for unfamiliar faces, and we demonstrate that this gain occurs for inverted as well as upright faces. We show that friend faces are recognized more quickly than unfamiliar faces in upright but not in inverted orientations, suggesting that configural processing underlies this particular advantage. Novel to this study is the finding that people are faster and more accurate at recognizing their own face over both stranger and friend faces and that these advantages occur for both upright and inverted faces. These findings are consistent with evidence for a bilateral representation of self-faces.