The Prominence of Self-referential Processing across ERP and Memory Consolidation in Children.

We examined behavioral and electrophysiological indices of self-referential and valence processing during a Self-Referential Encoding Task in 9- to 12-year-old children, followed by surprise memory tasks for self- and other-referential trait adjectives. Participants endorsed more positive than negative self-referential information but equally endorsed positive and negative information about the other character. Children demonstrated enhanced parietal LPP amplitudes in response to self- compared to other-referential trait adjectives. Positive and negative information was differentially remembered depending on the order of the referent cues presented, suggesting that social information undergoes differential consolidation processes depending on the referent and the order of presentation.

Are you as important as me? Self-other discrimination within trait-adjective processing.

Healthy adults typically display enhanced processing for self- (relative to other-) relevant and positive (relative to negative) information. However, it is unclear whether these two biases interact to form a self-positivity bias, whereby self-positive information receives prioritized processing. It is also unclear how a blocked versus mixed referent design impacts reference and valence processing. We addressed these questions using behavioral and electrophysiological indices across two studies using a Self-Referential Encoding Task, followed by surprise recall and recognition tasks. Early (P1) and late (LPP) event-related potentials were time-locked to a series of trait adjectives, encoded relative to oneself or a fictional character, with referent presented in a blocked (Exp. 1) or mixed (Exp. 2) trial design. Regardless of study design, participants recalled and recognized more self- than other-relevant adjectives, and recognized more positive than negative adjectives. Additionally, participants demonstrated larger LPP amplitudes for self-relevant and positive adjectives. The LPP self-relevance effect emerged earlier and persisted longer in the blocked (400-800 ms) versus mixed design (600-800 ms). The LPP valence effect was not apparent in the blocked design, but appeared late in the mixed design (600-1200 ms). Critically, the interaction between self-relevance and valence appeared only behaviorally in the mixed design, suggesting that overall self-relevance and valence independently impact neural socio-cognitive processing.

Chimpanzees gesture to humans in mirrors: using reflection to dissociate seeing from line of gaze.

There is much experimental evidence suggesting that chimpanzees understand that others see. However, previous research has never experimentally ruled out the alternative explanation that chimpanzees are just responding to the geometric cue of 'direct line of gaze', the observable correlate of seeing in others. Here, we sought to resolve this ambiguity by dissociating seeing from direct line of gaze using a mirror. We investigated the frequency of chimpanzees' visual gestures towards a human experimenter who could see them (as a result of looking into a mirror) but who lacked a direct line of gaze to them (as a result of having his/her head turned away). Chimpanzees produced significantly more visual gestures when the experimenter could see them than when he/she could not, even when the experimenter did not have a direct line of gaze to them. Results suggest that chimpanzees, through a possible process of experience projection based on their own prior experience with mirrors, infer that an experimenter looking at the mirror can see them. We discuss our results in relation to the theory of mind hypothesis that chimpanzees understand seeing in others, and we evaluate possible alternative low-level explanations.