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

Abstract

Abstract:Throughout evolution, hominids have developed greater capacity to think about themselves in abstract and symbolic ways. This process has reached its apex in humans with the construction of a concept of self as a distinct entity with a personal history. This chapter provides a review of recent functional neuroimaging studies that have investigated the neural correlates of such "higher-level" aspects of the human self, focusing in particular on processes that allow individuals to consciously represent and reflect on their own personal attributes (semantic forms of self-knowledge) and experiences (episodic forms of self-knowledge). These studies point to the medial prefrontal cortex (MPFC) as a key neural structure for processing various kinds of self-referential information. We speculate that the MPFC may mediate dynamic processes that appraise and code the self-relatedness or self-relevance of information. This brain region may thus play a key role in creating the mental model of the self that is displayed in our mind at a given moment.Sensing in Nature, edited by Carlos López-Larrea.

Personal semantics: at the crossroads of semantic and episodic memory

“…Autobiographical facts are typically relatively idiosyncratic (e.g., I know that my brother owns an old blue station wagon), which is compatible with the presumed role of the temporal pole in the retrieval of information associated with unique objects and individuals (e.g., [24,25]). The greater medial prefrontal activation for PS than for GS in Maguire's neuroimaging studies is consistent with the putative role of this brain region in self-referential processing [26]. Interestingly, compared to EM, PS has been associated with lesser activity in these three brain regions (i.e., medial prefrontal cortex, temporal pole, and retrosplenial cortex), as well as in the hippocampus [21,22,27].…”

“…In functional neuroimaging studies, medial prefrontal, temporal polar, retrosplenial, and precuneus regions seem to be critical for the representation of personal aspects of semantic memory ( Figure I). The medial prefrontal cortex, heavily involved in self-referential processing [26], is active in the most abstract forms of PS, namely autobiographical facts and self-knowledge (with activity centered around BA 10 in both cases). The temporal poles, known to support the representation of unique entities (e.g., [24,25]), are one of the brain regions most robustly associated with the representation of autobiographical facts.…”

Inter-individual variability in metacognitive ability for visuomotor performance and underlying brain structures

“…Evidence shows that RSP/PCC encodes contextual information to disambiguate stimuli (Miller, Vedder, Law, & Smith, 2014) and is critically implicated in self-referential processes linked to introspection and recollection (Kim, 2012;Schmitz & Johnson, 2007;Whitfield-Gabrieli et al, 2011), representation of self-knowledge in time (D'Argembeau & Salmon, 2012), and internal subjective decision-making (Johnson et al, 2005). Studies on meta-memory have suggested that confidence assessment during recollection is associated with differential engagement of self-monitoring functions mediated by the default network (Chua, Schacter, & Sperling, 2009), within which the RSC/PCC and precuneus both are key nodes.…”

On the Role of the Ventromedial Prefrontal Cortex in Self-Processing: The Valuation Hypothesis

“…Quite remarkably, however, there is growing evidence that the processing of various types of self-related contents – which form parts of the self-as-object – is commonly associated with activation of the medial portion of the prefrontal cortex (for recent reviews and meta-analyses, see Northoff et al, 2006; van der Meer et al, 2010; Qin and Northoff, 2011; Denny et al, 2012; D’Argembeau and Salmon, 2012; Murray et al, 2012; Wagner et al, 2012; Martinelli et al, 2013). …”

“…This idea that we attach unique significance to self-related contents may prove useful for interpreting one of the most consistent findings that has emerged from neuroimaging research on self-processing. Over the past decade, a growing number of studies have shown that the ventromedial prefrontal cortex (vMPFC) is activated when people contemplate various aspects of themselves and their life, such their traits, experiences, preferences, abilities, and goals (Northoff et al, 2006; Lieberman, 2010; D’Argembeau and Salmon, 2012; Wagner et al, 2012; Martinelli et al, 2013). However, while it is now common to see the vMPFC referenced as a “self region,” the precise mental operations mediated by this area remain poorly understood.…”