Resting state functional connectivity within the cingulate cortex jointly predicts agreeableness and stressor-evoked cardiovascular reactivity

Abstract

Exaggerated cardiovascular reactivity to stress is a risk factor for cardiovascular disease. Further, individual differences in stressor-evoked cardiovascular reactivity covary with the functionality of corticolimbic brain systems, particularly areas of the cingulate cortex. What remains unclear, however, is how individual differences in personality traits interact with cingulate functionality in the prediction of stressor-evoked cardiovascular reactivity. Accordingly, we tested the associations between (i) a particular personality trait, Agreeableness, which is associated with emotional reactions to conflict, (ii) resting state functional connectivity within the cingulate cortex, and (iii) stressor-evoked blood pressure (BP) reactivity. Participants (N=39, 19 men, aged 20-37 years) completed a resting functional connectivity MRI protocol, followed by two standardized stressor tasks that engaged conflict processing and evoked BP reactivity. Agreeableness covaried positively with BP reactivity across individuals. Moreover, connectivity analyses demonstrated that a more positive functional connectivity between the posterior cingulate (BA31) and the perigenual anterior cingulate (BA32) covaried positively with Agreeableness and with BP reactivity. Finally, statistical mediation analyses demonstrated that BA31-BA32 connectivity mediated the covariation between Agreeableness and BP reactivity. Functional connectivity within the cingulate appears to link Agreeableness and a risk factor for cardiovascular disease, stressor-evoked BP reactivity.

Figure 1

Displayed in red is the region of the perigenual cingulate cortex that was more strongly correlated with posterior cingulate cortex in individuals scoring higher in Agreeableness (Brodmann area 32; Talairach coordinates for peak activation voxel: X = −6, Y = 44, Z = 16. The cluster in blue is the region correlated with posterior cingulate cortex that was positively related to systolic blood pressure reactivity (Brodmann area 32; Talairach coordinates for peak activation voxel: X = −2, Y = 44, Z = 16). The seed region on which connectivity analyses are based is displayed in the lower right inset (X = −6, Y = −40, Z = 36). For discussion of seed selection, see supplementary figure S2.