Mapping the emotional homunculus with fMRI

Highlights•Observe to what extent the self-generated emotions map into the sensorimotor areas•Participants performed an emotional recall task during fMRI scanning•Sensorimotor maps are constructed from subjective tactile and motor stimulations•Recalled emotions overlapped with the reconstructed sensorimotor mapsSummaryEmotions are commonly associated with bodily sensations, e.g., boiling with anger when overwhelmed with rage. Studies have shown that emotions are related to specific body parts, suggesting that somatotopically organized cortical regions that commonly respond to somatosensory and motor experiences might be involved in the generation of emotions.We used functional magnetic resonance imaging to investigate whether the subjective feelings of emotion are accompanied by the activation of somatotopically defined sensorimotor brain regions, thus aiming to reconstruct an "emotional homunculus." By defining the convergence of the brain activation patterns evoked by self-generated emotions during scanning onto a sensorimotor map created on participants' tactile and motor brain activity, we showed that all the evoked emotions activated parts of this sensorimotor map, yet with considerable overlap among different emotions. Although we could not find a highly specific segmentation of discrete emotions over sensorimotor regions, our results support an embodied experience of emotions.Graphical abstract