1. Psychology Program, Lawrence Technological University, Southfield MI, USA.
3. MR Research Facility, Wayne State University, Detroit, MI, USA.
4. Psychology Department, Stonybrook University, Stonybrook, NY, USA.
Background: An evolutionary explanation concerning neural substrates of the self requires the ability by the brain to coordinate new sensory information in light of the organisms' internal states and in the context of its personal history and genetic inheritance. The aim of the present study was to demonstrate the experimental feasibility of a conception of the self as a distributed system consistent with predictions derived from evolutionary biology and neuroscience.
Methods: We used a 3T fMRI to compare Self vs. Other conditions in which 90 personality and 90 non-personality trait adjectives were rated as to whether they applied to Self, Best Friend, or Bill Gates, in a blocked-design paradigm.
Results: When comparing Self vs. Best Friend, we found significant activation in the dorsal posterior cingulate (BA 31), an area where the brain distinguishes egocentric and allocentric orientation, as well as in the substantia nigra and caudate nucleus, which are areas that reward successful action in the basal ganglia. We found an overlap of activation in the anterior cingulate cortex (BA 24) between the Self vs. Bill Gates and Best Friend vs. Bill Gates although the activation was greater in the former, as should be expected within an evolutionary approach.
Conclusions: The present study complements other neuroimaging studies of the self while resolving contradictions and paradoxes created by more traditional conceptions of the self.
Keywords: Self-attribution, fMRI, neuroimaging, evolutionary explanation, theory of mind, distributed activation in the brain