Social brain networks: Resting-state and task-based connectivity in youth with and without epilepsy

Abstract

Individuals with epilepsy often experience social difficulties and deficits in social cognition. It remains unknown how disruptions to neural networks underlying such skills may contribute to this clinical phenotype. The current study compared the organization of relevant brain circuits-the "mentalizing network" and a salience-related network centered on the amygdala-in youth with and without epilepsy. Functional connectivity between the nodes of these networks was assessed, both at rest and during engagement in a social cognitive task (facial emotion recognition), using functional magnetic resonance imaging. There were no group differences in resting-state connectivity within either neural network. In contrast, youth with epilepsy showed comparatively lower connectivity between the left posterior superior temporal sulcus and the medial prefrontal cortex-but greater connectivity within the left temporal lobe-when viewing faces in the task. These findings suggest that the organization of a mentalizing network underpinning social cognition may be disrupted in youth with epilepsy, though differences in connectivity within this circuit may shift depending on task demands. Our results highlight the importance of considering functional task-based engagement of neural systems in characterizations of network dysfunction in epilepsy.

Keywords: Epilepsy; Functional connectivity; Network; Resting-state; Social brain.

Fig. 1.

Note. Regions of interest in the mentalizing network. Regions of interest were based on those outlined in Mills et al. (2014). L = left, R = right. ATC = anterior temporal cortex, mPFC = medial prefrontal cortex, pSTS = posterior superior temporal sulcus, pTPJ = posterior temporo-parietal junction.

Fig. 2.

Note. Regions of interest in the amygdala network. Regions of interest were based on those described in Kennedy and Adolphs (2012). L = left, R = right. FG = fusiform gyrus, OFC = orbitofrontal cortex, Amg = amygdala.

Fig. 3.

Note. Group differences in task-based functional connectivity in the mentalizing network. Figure depicts significant effects of Group (typically-developing [TD] youth vs. youth with epilepsy) on task-based connectivity in the mentalizing network. R = right, L = left. pSTS = posterior superior temporal sulcus, pTPJ = posterior temporo-parietal junction, mPFC = medial prefrontal cortex, ATC = anterior temporal cortex. Red and blue lines on the connectome images represent connections that were weaker and stronger in youth with epilepsy compared to TD youth, respectively; grey lines represent connections for which the groups did not differ. The mPFC target in the top row is represented as two nodes in the graph but is located at the midline.

Fig. 4.

Note. Group differences in age-related changes in task-based connectivity. Figure depicts significant interactions of Group (typically-developing [TD] youth vs. youth with epilepsy) × Age (in years) on task-based connectivity with three seed regions. R = right, L = left. pSTS = posterior superior temporal sulcus, mPFC = medial prefrontal cortex, ATC = anterior temporal cortex, OFC = orbitofrontal cortex.