Xun Liu

Anterior insular cortex is necessary for empathetic pain perception

Authors:

  • Xiaosi Gu

  • Zhixian Gao

  • Xingchao Wang

  • Xun Liu

  • Robert T. Knight

  • Patrick R. Hof

  • Jin Fan

Date: 2012

DOI: 10.1093/brain/aws199

PubMed: 22961548

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Abstract:

Empathy refers to the ability to perceive and share another person's affective state. Much neuroimaging evidence suggests that observing others' suffering and pain elicits activations of the anterior insular and the anterior cingulate cortices associated with subjective empathetic responses in the observer. However, these observations do not provide causal evidence for the respective roles of anterior insular and anterior cingulate cortices in empathetic pain. Therefore, whether these regions are 'necessary' for empathetic pain remains unknown. Herein, we examined the perception of others' pain in patients with anterior insular cortex or anterior cingulate cortex lesions whose locations matched with the anterior insular cortex or anterior cingulate cortex clusters identified by a meta-analysis on neuroimaging studies of empathetic pain perception. Patients with focal anterior insular cortex lesions displayed decreased discrimination accuracy and prolonged reaction time when processing others' pain explicitly and lacked a typical interference effect of empathetic pain on the performance of a pain-irrelevant task. In contrast, these deficits were not observed in patients with anterior cingulate cortex lesions. These findings reveal that only discrete anterior insular cortex lesions, but not anterior cingulate cortex lesions, result in deficits in explicit and implicit pain perception, supporting a critical role of anterior insular cortex in empathetic pain processing. Our findings have implications for a wide range of neuropsychiatric illnesses characterized by prominent deficits in higher-level social functioning.

Effective Connectivity of the Fronto-parietal Network during Attentional Control

Authors:

  • Liang Wang

  • Xun Liu

  • Kevin Guise

  • Robert T. Knight

  • Jamshid Ghajar

  • Jin Fan

Date: 2010

DOI: 10.1162/jocn.2009.21210

PubMed: 19301995

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Abstract:

The ACC, the dorsolateral prefrontal cortex (DLPFC), and the parietal cortex near/along the intraparietal sulcus (IPS) are members of a network subserving attentional control. Our recent study revealed that these regions participate in both response anticipation and conflict processing. However, little is known about the relative contribution of these regions in attentional control and how the dynamic interactions among these regions are modulated by detection of predicted versus unpredicted targets and conflict processing. Here, we examined effective connectivity using dynamic causal modeling among these three regions during a flanker task with or without a target onset cue. We compared various models in which different connections among ACC, DLPFC, and IPS were modulated by bottom-up stimulus-driven surprise and top-down conflict processing using Bayesian model selection procedures. The most optimal of these models incorporated contextual modulation that allowed processing of unexpected (surprising) targets to mediate the influence of the IPS over ACC and DLPFC and conflict processing to mediate the influence of ACC and DLPFC over the IPS. This result suggests that the IPS plays an initiative role in this network in the processing of surprise targets, whereas ACC and DLPFC interact with each other to resolve conflict through attentional modulation implemented via the IPS.