Self-reflection across time: cortical midline structures differentiate between present and past selves

Abstract

The processing of personal changes across time and the ability to differentiate between representations of present and past selves are crucial for developing a mature sense of identity. In this study, we explored the neural correlates of self-reflection across time using functional magnetic resonance imaging (fMRI). College undergraduates were asked to reflect on their own psychological characteristics and those of an intimate other, for both the present time period (i.e. at college) and a past time period (i.e. high school years) that involved significant personal changes. Cortical midline structures (CMS) were commonly recruited by the four reflective tasks (reflecting on the present self, past self, present other and past other), relative to a control condition (making valence judgments). More importantly, however, the degree of activity in CMS also varied significantly according to the target of reflection, with the ventral and dorsal medial prefrontal cortex and the posterior cingulate cortex being more recruited when reflecting on the present self than when reflecting on the past self or when reflecting on the other person. These findings suggest that CMS may contribute to differentiate between representations of present and past selves.

The Neural Basis of Semantic and Episodic Forms of Self-Knowledge: Insights from Functional Neuroimaging

“…They found that the same MPFC region previously identified as more activated when thinking about the self versus a nonclose other was also more activated when thinking about the self versus an intimate other. Similar results have been obtained in most reports, 15,29,30 although some studies failed to detect differential activity in the MPFC when contrasting judgments referring to the self with judgments referring to a close other. 31,32 The reasons for these divergent findings remain unclear but a possible explanation would be that the difference in MPFC activity when contrasting self and close other conditions depends on the perceived similarity or overlap between oneself and close others, which in turn varies across individuals and situations.…”

“…White circles represent the locations of peak MPFC activations detected when reflecting on one's own psychological traits relative to reflecting on the traits of others or making semantic judgements. [13][14][15][16][17][18][19][20][21][22][23]25,26,29,30 White squares represent the locations of peak MPFC activations detected when reflecting on one's own promotion goals. [38][39][40][41] when participants made judgments from their own perspective and when they made judgments from the perspective of their friend.…”

“…27,74 On the other hand, other researchers have suggested that the MPFC may play some specific role in self-referential processing. 8,28,29,67,75,76 It has been suggested, in particular, that the MPFC may support supramodal processes that, explicitly or implicitly, appraise and code the self-relatedness or self-relevance of multiple sources of information. 8,67,76 According to this view, the MPFC may mediate dynamic processes that locate external stimuli and internal representations on a continuum of personal relevance.…”

“…29 The MPFC might thus contribute to the great splitting of the universe made by each of us that William James referred to more than a century ago. 1 Of course, we agree that the creation of our sense of self involves multiple nonself-specific processes, such as memory and reasoning processes.…”

Brain circuits implicated in psychogenic paralysis in conversion disorders and hypnosis

“…Both VMPFC and precuneus are implicated in representations of the self-including [63] autobiographical memory [82] and self-reflexive imagery [14]. VMPFC is particularly recruited in tasks requiring access to affectively relevant information about the self, including personal traits judgments [21,43,84], introspection on one's own feelings [44,46,52,69] and retrieval of emotional information from either past or prospective memory [20,91]. This region is also activated in response to incidental information related to the self without explicit task demands or conscious will [58].…”