Neural underpinnings of a two-phase memory suppression process in the neural response to self-related and observed...

Individuals often actively suppress intrusive memories to alleviate the distress they cause and maintain mental well-being. However, those with post-traumatic stress disorder (PTSD) often exhibit difficulties particularly in inhibiting or suppressing negative memories compared to individuals without PTSD. These memories can involve a physical threat either to the individual themselves or to others. Unfortunately, there is still limited understanding of the cognitive and neural mechanisms that underlie how suppression differs for self-related versus other-related memories. Here we capitalized on multivariate pattern analyses in combination with fMRI data acquired during a two-phase memory suppression paradigm where participants volitionally suppressed and subsequently recognized self-related and other-related stimuli. The results suggested that the recognition process following memory suppression demands more cognitive engagement for self-related stimuli than other-related stimuli, manifesting in increased activity in the dorsal anterior cingulate cortex (dACC). Furthermore, after memory suppression, we observed a stronger functional coupling between dACC identified during memory suppression, and both the middle frontal gyrus and the insula during self-related recognition compared to other-related recognition. An advanced multivariate pattern analysis substantiated that the limbic system and empathy network particularly contributed to accurately distinguishing between self-related and other-related recognition following memory suppression. Our findings demonstrated distinct neural representations of memory suppression related to self and others, suggesting that different strategies may be employed for suppressing intrusive memories originating from different sources.