Experimental design and behavioral results
(A) Self- and other-related stimuli (names, surnames, dates of birth, nationality codes) were presented visually and the participant's task was to decide (by pressing one of the two buttons) whether stimuli occurring at the end of each trial (targets; indicated here by orange triangles) were related to themselves or another person. In half of the trials, stimuli appearing before the targets (primes; white triangles) were immediately preceded and followed by visual masks, which made aware processing of these primes highly demanding. In the other half of the trials, there were no masks, which made aware processing easy. Stimuli durations and intervals are indicated in milliseconds, next to the time axis. (B) As intended, the masking procedure made discrimination of primes more difficult (zero indicates chance level; medians ± interquartile ranges). (C) The priming effect (reaction times: incongruent > congruent trials) was significantly stronger in the self conditions than in the other conditions, and stronger in the aware than unaware conditions (means ± standard errors).
BOLD adaptation results
Brain regions related to (A) conceptual self-awareness, (B) perceptual awareness, (C) unaware processing of self-related information, and (D) unaware processing of all types of stimuli. Areas showing significant BOLD-adaptation are highlighted in red. Bar plots show the BOLD-adaptation effect (incongruent > congruent trials). Error bars denote standard errors. Abbreviations: FG - fusiform gyrus; HI - hippocampus; IPS - intraparietal sulcus; IT - inferior temporal cortex; MFP - medial frontal pole; PCS - precentral sulcus; PH - parahippocampal gyrus; RSC -retrosplenial cortex; SMA - supplementary motor area; TP - temporal pole.
Overlap between the self-awareness network and the default mode network
Neural responses selective to self-awareness (SA; green) are based on the BOLD-adaptation analysis. A map of default mode network functional connectivity (red) is based on resting-state data collected from the same group of participants. The overlap is present especially in the medial prefrontal and posterior cingulate regions (yellow).