Empathy for positive and negative emotions in the gustatory cortex

Area of Science:

• Neuroscience
• Cognitive Psychology
• Affective Science

Background:

• The anterior insula and adjacent frontal operculum (IFO) are activated by gustatory and olfactory stimuli, particularly those eliciting disgust.
• Lesion studies suggest the IFO plays a critical role in processing disgust-related stimuli.
• Previous research has primarily focused on the IFO's role in negative emotions and empathy for pain.

Purpose of the Study:

• To investigate the involvement of the IFO in processing the gustatory emotions of others more broadly.
• To explore the relationship between individual empathy levels and IFO activation during the observation of others' gustatory emotions.
• To determine if the IFO's role in empathy extends beyond negative emotions to include positive affective states.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity.
• Participants were exposed to food-related facial expressions depicting disgust, pleasure, and neutrality.
• Participants also tasted pleasant, unpleasant, and neutral tastants, and their self-reported empathy was measured using the Interpersonal Reactivity Index (IRI).

Main Results:

• IFO activation was observed during the viewing of both pleased and disgusted facial expressions.
• Participants' empathy scores, as measured by the IRI, predicted their IFO activation when witnessing others' gustatory emotions.
• This predictive relationship was evident for both positive (pleased) and negative (disgusted) emotional expressions.

Conclusions:

• The IFO's role in empathy extends to processing positive emotions, not just negative ones.
• The findings support the interoceptive function of the IFO in empathy, suggesting it maps others' bodily feelings onto the observer's internal bodily states.
• This study provides empirical support for the IFO's contribution to a broader range of empathic experiences.