Neural correlates of different self domains

Abstract

Introduction: The neural substrates of states devoted to processing self-related information ("self-related states") remain not fully elucidated. Besides the complexity of the problem, there is evidence suggesting that self-related states vary according to the information domain being considered. Here, we investigated brain correlates for self-related states concerning historical aspects of one's life (autobiographical self), and one's ongoing body status (core self). We focused on memory-related regions, body-related regions, CMSs (cortical midline structures), and ICs (insular cortices).

Methods: This was a block-design fMRI study contrasting brain activity for core self (interoception and exteroception) and autobiographical self (personality traits and biographic facts) information domains. It involved 19 participants, who answered questions about each domain (four conditions).

Results: All conditions appeared to engage the regions of interest. Nonetheless, autobiographical self compared with core self showed greater activity in memory-related regions (e.g., hippocampus), MPFC (medial prefrontal cortex), superior PMC (posteromedial cortex), and anterior ICs. Core self compared with autobiographical self was associated with greater activity in body-related regions (e.g., somatosensory cortices, and EBA [extrastriate body area]), superior PMC, and posterior ICs. In addition, (1) facts compared with traits showed greater activity in body-related regions, memory-related regions, MPFC, and PMC; (2) traits compared with facts were associated with greater activity in the posterior part of the anterior cingulate cortex; (3) interoception compared with exteroception was associated with greater activity in body-related regions (e.g. postcentral gyrus), memory-related regions, MPFC, inferior PMC and ICs; (4) exteroception compared with interoception showed greater activity in some body-related regions (e.g., premotor cortices and EBA) and superior PMC.

Conclusions: The results support the notion that the neural correlates of self-related states depend on the information domain. Those states seem distinguishable in terms of activity in memory-related and body-related regions, and activity in regions that have been associated with self processes (CMSs and the ICs).

Keywords: Autobiographical self; core self; exteroception; interoception; memory; self.

Figure 1

Facts and traits compared with core self conditions. These are results from a conjunction analysis for the following contrasts: facts > (interoception + exteroception), and traits > (interoception + exteroception). Thus, these brain regions showed greater signal for autobiographical self questions than for core self questions. LH, left hemisphere; RH, right hemisphere.

Figure 2

Interoception and exteroception compared with autobiographical self conditions. The images derive from a conjunction analysis for the following contrasts: interoception > (facts + traits), and exteroception > (facts + traits). Thus, these brain regions showed greater signal for core self questions than for autobiographical self questions. LH, left hemisphere; RH, right hemisphere.

Figure 3

Facts versus traits. The red‐yellow color scale shows brain regions with significantly greater signal for facts than for traits. The blue‐green scale shows brain regions with greater signal for questions targeting traits than for those targeting facts. LH, left hemisphere; RH, right hemisphere.

Figure 4

Interoception versus exteroception. The red‐yellow color scale shows brain regions with significantly greater signal for interoception than for exteroception. The blue‐green scale shows brain regions with greater signal for questions regarding exteroception than for those regarding interoception. LH, left hemisphere; RH, right hemisphere.

Figure 5

Parameter estimates for each condition in cortical midline structures. Regions of interests consisted of spheres of 5 mm radius centered on activation peaks in the medial prefrontal cortex and in the posteromedial cortex from the conjunction analyses. MNI coordinates (x, y, z) in parentheses; error bars represent standard error mean.