Intrinsic amygdala-cortical functional connectivity predicts social network size in humans

Abstract

Using resting-state functional magnetic resonance imaging data from two independent samples of healthy adults, we parsed the amygdala's intrinsic connectivity into three partially distinct large-scale networks that strongly resemble the known anatomical organization of amygdale connectivity in rodents and monkeys. Moreover, in a third independent sample, we discovered that people who fostered and maintained larger and more complex social networks not only had larger amygdala volumes, but also amygdalae with stronger intrinsic connectivity within two of these networks: one putatively subserving perceptual abilities and one subserving affiliative behaviors. Our findings were anatomically specific to amygdalar circuitry in that individual differences in social network size and complexity could not be explained by the strength of intrinsic connectivity between no des within two networks that do not typically involve theamygdala (i.e., the mentalizingandmirror networks), and were behaviorally specific in that amygdala connectivity did not correlate with other self-report measures of sociality. © 2012 the authors.