Present-self, past-self and the close-other: neural correlates of assigning trait adjectives to oneself and others.

Information regarding the past-self may be viewed as information referring to other people. However, evidence supporting this notion at the neural level is rather sparse and it remains unclear whether the past-self is processed like any 'other' or like the close-other only. The aim of this event-related potential study was to investigate this issue. A reflection task requiring evaluation of positive and negative trait adjectives with respect to present- and past-self, a close-other and a famous person was applied. We hypothesized that the past-self and close-other conditions would share their neural underpinnings. The process of reflection on the past-self and close-other was indeed associated with similar mean amplitudes of the late positive component (LPC), whereas in the case of the past-self vs. famous person comparison LPC was significantly enhanced for the past-self. Analogous effects were observed when LPC was calculated for trials with traits judged as either suitable or unsuitable to describe a person who was the target of reflection. Thus, these findings suggest that the processing of information related to the past-self resembles processing of information related to a personally relevant other. Moreover, sex-differences were observed in reaction times and LPC amplitudes for responses reflecting the positivity bias.