The Effect of High-Definition Transcranial Direct Current Stimulation of the Right Inferior Frontal Gyrus on Empathy in Healthy Individuals

Abstract

Empathy, including cognitive and emotional empathy, refers to the ability to infer the mental states of others and to the capacity to share emotions. The neural mechanisms involved in empathy are complex and not yet fully understood, and previous studies have shown that both cognitive and emotional empathy are closely associated with the inferior frontal gyrus (IFG). In this study, we examined whether empathy can be modulated by high-definition transcranial direct current stimulation (HD-tDCS) of the right IFG. Twenty-three healthy participants took part in all three experimental conditions (i.e., anodal, cathodal and sham stimulation) in a randomized order. Participants then completed the Chinese version of the Multifaceted Empathy Test (MET), which assesses both cognitive and emotional empathy. The results show that scores obtained for cognitive empathy following cathodal stimulation are significantly lower than those obtained following sham stimulation. In addition, scores obtained for cognitive empathy following anodal stimulation are higher than those obtained following sham stimulation, though the difference is only marginally significant. However, the results fail to show whether the stimulation of the right IFG via HD-tDCS plays a role in emotional empathy. Our results suggest that the right IFG plays a key role in cognitive empathy and indicate that HD-tDCS can regulate cognitive empathy by inducing excitability changes in the right IFG.

Probing the role of the right inferior frontal gyrus during Pain‐Related empathy processing: Evidence from fMRI and TMS

“…The rIFG may be involved in emotion recognition (through emotional‐communicative information, such as facial expressions) and conversion of the observed facial expressions of pain into a pattern of neural activity that would enable the observer to infer the state of the expresser, thus providing the neural basis for emotional empathy. In line with these observations, non‐pain facial expression‐based empathy necessitates the activity of the rIFG, as revealed by a recent cortical stimulation study (Wu et al, 2018). However, a few studies have also found that, when participants focused on pain using objective cues about the sensory component of the observed pain (e.g., pain in limbs), the rIFG also demonstrated stronger activation (Grèzes, Armony, Rowe, & Passingham, 2003; Iacoboni, 2005; Iacoboni, 2009; Vachon‐Presseau et al, 2012).…”

“…However, Massey et al found that decreased cortical thickness of the rIFG was associated with worse performance in cognitive empathy tasks among individuals with schizophrenia (Massey et al, 2017). In line with these observations, cognitive empathy necessitates the activity of the rIFG, as revealed by a recent tDCS brain stimulation study, and this tDCS effect is also negatively correlated with scores on the FS subscale (Wu et al, 2018).…”

“…Recently, noninvasive brain stimulation methods, such as transcranial magnetic stimulation (TMS)/transcranial direct current stimulation (tDCS), have come to be used widely to detect brain-behavior interactions (Valero-Cabré, Amengual, Stengel, Pascual-Leone, & Coubard, 2017). A recent tDCS study provided evidence for the role of the rIFG in empathy activated by non-pain facial expressions (Wu et al, 2018). Nevertheless, imaging methods merely detect associations between activation of a certain brain region and behavior.…”

Wasting food is disgusting: Evidence from behavioral and neuroimaging study of moral judgment of food-wasting behavior

“…Moral judgment of food-wasting and harmful scenarios also revealed an increased activation in several unique areas (absent in morally disgusting and dishonest conditions) including the bilateral Supplementary Motor Area, as well as the Inferior Frontal Gyrus, Putamen and the Amygdala in the left hemisphere. These regions correspond with the neural network involved in empathy (Del Casale et al, 2017; Goerlich-Dobre, Lamm, Pripfl, Habel, & Votinov, 2015; Wu et al, 2018). However, we did not observe activation of the so-called pain matrix (anterior Insula, anterior Cingulate Cortex), which in previous studies consistently showed increased activation while experiencing pain oneself, as well as while watching others experience pain (Lamm, Decety, & Singer, 2011).…”

Impaired Cognitive Empathy in Outpatients with Chronic Musculoskeletal Pain: A Cross-Sectional Study

“…First, participants' trait cognitive empathy and trait emotional empathy were measured using the IRI, which has four subscales: the perspective-taking and fantasy subscales represent cognitive empathy, while the empathic concern and personal distress subscales represent emotional empathy [ 28 , 29 ]. Second, as the MET has higher ecological validity for assessing cognitive empathy and emotional empathy than self-reported questionnaires [ 30 ], the Chinese version of this task (MET-C) was also used. It involves 40 pictures of people in various emotional states (20 positive and 20 negative emotional valence pictures).…”