Interactions between the processing of emotion expression and form-based information from faces (facial identity) were investigated using the redundant-target paradigm, in which we specifically tested whether identity and emotional expression are integrated in a superadditive manner (Miller, Cognitive Psychology 14:247-279, 1982). In Experiments 1 and 2, participants performed emotion and face identity judgments on faces with sad or angry emotional expressions. Responses to redundant targets were faster than responses to either single target when a universal emotion was conveyed, and performance violated the predictions from a model assuming independent processing of emotion and face identity. Experiment 4 showed that these effects were not modulated by varying interstimulus and nontarget contingencies, and Experiment 5 demonstrated that the redundancy gains were eliminated when faces were inverted. Taken together, these results suggest that the identification of emotion and facial identity interact in face processing.

We examined whether self-biases in perceptual matching reflect the positive valence of self-related stimuli. Participants associated geometric shapes with either personal labels (e.g., you, friend, stranger) or faces with different emotional expressions (e.g., happy, neutral, sad). They then judged whether shape-label or shape-face pairs were as originally shown or re-paired. Match times were faster to self-associated stimuli and to stimuli associated with the most positive valence. In addition, both the self-bias and the positive emotion bias were reliable across individuals in different test sessions. In contrast there was no sign of a correlation between the self-bias and the emotion-bias effects. We argue that self-bias and the bias to stimuli linked to positive emotion are separate and may reflect different underlying processes.

Participants are biased in responding to stimuli associated with themselves compared with stimuli related to other people. This self-bias may reflect the reward value of self-related stimuli (Sui, He, & Humphreys, 2012). In this article, we examined the identification of self- and reward-associated stimuli under conditions in which either single or redundant stimuli were presented. The redundant stimuli could be the same shape or they could be different shapes both associated with either the self or a friend or high or low reward. We formally tested whether the redundant stimuli violated the independent race model for the identification of multiple stimuli (Miller, 1982) and whether the redundant stimuli were processed with super- or limited-capacity (Townsend & Eidels, 2011). We found that redundant self stimuli alone both violated the independent race model and were processed with super-capacity. In contrast, the redundant high reward stimuli did not show race inequality and were associated with limited capacity processing. The data advance our theoretical understanding of self bias both by demonstrating that it can be distinguished from effects of reward, and by suggesting that self-bias can result from the enhanced integration of stimuli associated with the self. The implications for understanding self bias effects are discussed.

Although theoretical discourse and experimental studies on the self- and reward-biases have a long tradition, currently we have only a limited understanding of how the biases are represented in the brain and, more importantly, how they relate to each other. We used multi-voxel pattern analysis to test for common representations of self and reward in perceptual matching in healthy human subjects. Voxels across an anterior–posterior axis in ventromedial prefrontal cortex (vmPFC) distinguished (i) self–others and (ii) high–low reward, but cross-generalization between these dimensions decreased from anterior to posterior vmPFC. The vmPFC is characterized by a shift from a common currency for value to independent, distributed representations of self and reward across an anterior–posterior axis. This shift reflected changes in functional connectivity between the posterior part of the vmPFC and the frontal pole when processing self-associated stimuli, and the middle frontal gyrus when processing stimuli associated with high reward. The changes in functional connectivity were correlated with behavioral biases, respectively, to the self and reward. The distinct representations of self and reward in the posterior vmPFC are associated with self- and reward-biases in behavior.

In their seminal paper 'Is our self nothing but reward', Northoff and Hayes (Biol Psychiatry 69(11):1019-1025, Northoff, Hayes, Biological Psychiatry 69(11):1019-1025, 2011) proposed three models of the relationship between self and reward and opened a continuing debate about how these different fields can be linked. To date, none of the proposed models received strong empirical support. The present study tested common and distinct effects of personal relevance and reward values by de-componenting different stages of perceptual decision making using a drift-diffusion approach. We employed a recently developed associative matching paradigm where participants (N = 40) formed mental associations between five geometric shapes and five labels referring personal relevance in the personal task, or five shape-label pairings with different reward values in the reward task and then performed a matching task by indicating whether a displayed shape-label pairing was correct or incorrect. We found that common effects of personal relevance and monetary reward were manifested in the facilitation of behavioural performance for high personal relevance and high reward value as socially important signals. The differential effects between personal and monetary relevance reflected non-decisional time in a perceptual decision process, and task-specific prioritization of stimuli. Our findings support the parallel processing model (Northoff & Hayes, Biol Psychiatry 69(11):1019-1025, Northoff, Hayes, Biological Psychiatry 69(11):1019-1025, 2011) and suggest that self-specific processing occurs in parallel with high reward processing. Limitations and further directions are discussed.

We examined relations between the processing of facial identity and emotion in own- and other-race faces, using a fully crossed design with participants from 3 different ethnicities. The benefits of redundant identity and emotion signals were evaluated and formally tested in relation to models of independent and coactive feature processing and measures of processing capacity for the different types of stimuli. There was evidence for coactive processing of identity and emotion that was linked to super capacity for own-race but not for other-race faces. In addition, the size of the redundancy gain for other-race faces varied with the amount of social contact participants had with individuals from the other race. The data demonstrate qualitative differences in the processing of facial identity and emotion cues in own and other races. The results also demonstrate that the level of integration of identity and emotion cues in faces may be determined by life experience and exposure to individuals of different ethnicities.

We present novel data on the role of attention in eliciting enhanced processing of stimuli associated with self. Participants were required to make pro-or anti-saccades according to whether learned shape-label pairings matched or mismatched. When stimuli matched participants were required to make an anti-saccade and when the stimuli mismatched a pro-saccade was required. We found that anti-saccades were difficult to make to stimuli associated with self when compared to stimuli associated with a friend and a stranger. In contrast, anti-saccades to friend-stimuli were easier to make than antisaccades to stranger-stimuli. In addition, a correct anti-saccade to a self-associated stimulus disrupted subsequent pro-saccade trials, relative to when the preceding anti-saccade was made to other stimuli. The data indicate that self-associated stimuli provide a strong cue for explicit shifts of attention to them, and that correct anti-saccades to such stimuli demand high levels of inhibition (which carries over to subsequent pro-saccade trials). The self exerts an automatic draw on attention.4

Self and emotions are key motivational factors of a person strivings for health and well-being. Understanding neural mechanisms supporting the relationship between these factors bear far-reaching implications for mental health disorders. Recent work indicates a substantial overlap between self-relevant and emotion information processing and has proposed the medial prefrontal cortex (MPFC) as one shared neural signature. However, the precise cognitive and neural mechanisms represented by the MPFC in investigations of self- and emotion-related processing are largely unknown. Here we examined whether the neural underpinnings of self-related processing in the MPFC link to positive or negative emotions. We collected fMRI data to test the distinct and shared neural circuits of self- and emotion-related processing while participants performed personal (self, friend, or stranger) and emotion (happy, sad, or neutral) associative matching tasks. By exploiting tight control over the factors that determine the effects of self-relevance and emotions (positive: Happy vs. neutral; negative: Sad vs. neutral), our univariate analysis revealed that the ventral part of the MPFC (vmPFC), which has established involvement in self-prioritisation effects, was not recruited in the negative emotion prioritisation effect. In contrast, there were no differences in brain activity between the effects of positive emotion- and self-prioritisation. These results were replicated by both region of interest (ROI)-based analysis in the vmPFC and the seed- to voxel functional connectivity analysis between the MPFC and the rest of the brain. The results suggest that the prioritisation effects for self and positive emotions are tightly linked together, and the MPFC plays a large role in discriminating between positive and negative emotions in relation to self-relevance.