Perigenual anterior cingulate morphology covaries with perceived social standing

Abstract

Low socioeconomic status (SES) increases the risk for developing psychiatric and chronic medical disorders. A stress-related pathway by which low SES may affect mental and physical health is through the perception of holding a low social standing, termed low subjective social status. This proposal implicates overlapping brain regions mediating stress reactivity and socioemotional behaviors as neuroanatomical substrates that could plausibly link subjective social status to health-related outcomes. In a test of this proposal, we used a computational structural neuroimaging method (voxel-based morphometry) in a healthy community sample to examine the relationships between reports of subjective social status and regional gray matter volume. Results showed that after accounting for potential demographic confounds, subclinical depressive symptoms, dispositional forms of negative emotionality and conventional indicators of SES, self-reports of low subjective social status uniquely covaried with reduced gray matter volume in the perigenual area of the anterior cingulate cortex (pACC)-a brain region involved in experiencing emotions and regulating behavioral and physiological reactivity to psychosocial stress. The pACC may represent a neuroanatomical substrate by which perceived social standing relates to mental and physical health.

Keywords: anterior cingulate cortex; gray matter volume; socioeconomic status; stress; subjective social status.

Fig. 1

Lower subjective social status, as reflected by a lower self-reported ranking on a ‘social ladder’, was associated with reduced gray matter volume in the perigenual area of the anterior cingulate cortex (pACC). (A) Illustration of 10-point social ladder scale used to assess subjective social status (instructions provided in the appendix). (B) Overlaid on a sagittal view of an anatomical template generated from the present sample is a statistical parametric map of color-scaled t-values, which illustrate the pACC area where lower subjective social status was associated with reduced gray matter volume in a multiple regression analysis. The regression analysis controlled for conventional indicators of personal socioeconomic status (assessed by family income and education) and community socioeconomic status (assessed by census tract information reflecting social advantage), as well as age, sex and total gray matter volume. (C) Plotted along the y-axis is the standardized (z-score) gray matter volume from the peak pACC voxel within the cluster of voxels profiled in B. Plotted along the x-axis are social ladder rankings from the scale illustrated in A (1 = ‘Worst Off’, 10 = ‘Best Off’). *P < 0.001.

Fig. 2

A whole-brain exploratory analysis demonstrated that lower subjective social status was associated with reduced gray matter volume only in the bilateral perigenual anterior cingulate cortex (pACC), after cluster-level correction for multiple statistical testing across the entire brain volume (P < 0.05). Illustrating this pACC area is a statistical parametric map of color-scaled t-values overlaid onto left (A) and right (C) sagittal sections and a coronal section (B) of an anatomical template derived from the present sample. Montreal Neurological Institute coordinates in A–C refer to the distance in mm from the midline for sagittal sections (+ = right; – = left) and from the anterior commissure for the coronal section.