Modulation of cortical midline structures by implicit and explicit self-relevance evaluation

Abstract

Recent neuroimaging work has observed activity in cortical midline structures (CMS) such as medial prefrontal and posterior cingulate cortices during self-referential processing. Moreover, items rated as self-relevant produce increased activity in these regions relative to items that are deemed not self-relevant. A common thread among previous reports has been reliance on experimental tasks that encourage or require online self-referential processing. In this paper, we report findings from two experiments that manipulated requirements for self-reflection. In Experiment 1, subjects rated trait adjectives for social desirability and for self-relevance. Results revealed increasing activity in CMS with increasing self-relevance, but only during explicit ratings of self-relevance. In Experiment 2, we examined CMS activity during passive viewing of personal semantic facts (such as subjects’ own first names). Taken together, these results suggest that highly self-relevant information captures attention through neural mechanisms that are comparable to those engaged during explicit self-reflection, namely via recruitment of CMS structures.

Keywords:

• Medial prefrontal cortex
• Posterior cingulate cortex
• fMRI
• Self-relevance
• Social cognitive neuroscience

Acknowledgements

We thank T. Moran for her technical assistance. This work comprised part of JMM's doctoral thesis at Dartmouth College, and JMM thanks committee members J. D. E. Gabrieli and P. J. Whalen for helpful comments throughout. This work was supported by the Dartmouth Brain Imaging Center.