Synchronous with Your Feelings: Sensorimotor γ Band and Empathy for Pain

Abstract

Neuroscience studies on the social sharing of observed or imagined pain focused on whether empathic pain resonance is linked to affective or sensory nodes of the pain matrix. However, empathy, like other complex cognitive processes, is inherently linked to the activation of functional networks rather than of separate brain areas. Here, we used magnetoencephalography (MEG) to explore the relationship between empathy and functional coupling of neuronal activity in primary somatosensory (SI) and motor (MI) cortices. MEG recording was performed while healthy participants observed movie-clips depicting the static hand of a stranger model, the same hand deeply penetrated by a needle, or gently touched by a Q-tip. Subjects were asked to rate the movie-derived sensations attributed to self or to the model. For each type of clip observation, we analyzed spectral power and coherence values in ␣, ␤, and ␥ frequency bands. While spectral power indexes separate neural activity in SI and MI, coherence values index functional cross-talk between these two areas. No power changes of SI or MI sources were induced by observation conditions in any of the frequency bands. Crucially, ␥-band coherence values were significantly higher during needle-in-hand than touch and static hand observation and correlated with self-and otherreferred pain ratings derived from needle-in-hand movies observation. Thus, observation of others' pain increases neuronal synchronization and cross-talk between the onlookers' sensory and motor cortices, indicating that empathic resonance relies upon the activity of functional networks more than of single areas.

Seeing touch in the somatosensory cortex: A TMS study of the visual perception of touch

“…A recent study demonstrated that TMS over SI selectively reduced the typical corticospinal mapping of biomechanically impossible movements [Fadiga et al, 1995[Fadiga et al, , 2005Romani et al, 2005], which were associated with aversive somatic feelings, without impacting mirror responses to possible movements that did not evoke somatic feelings in the observer. Modulation of SI activity that is contingent upon observation of others' pain has also been described [Betti et al, 2009;Bufalari et al, 2007]. Therefore, it seems that the mirror function of SI is that of preferentially encoding the somatic component of action simulation.…”

“…Action observation and execution increases neural activity in both motor and somatosensory areas [Rizzolatti and Craighero, 2004]. Crucially, making the perceived action painful or more salient from a tactile or proprioceptive point of view causes an increase of the activity in SI Betti et al, 2009;Bufalari et al, 2007;Costantini et al, 2005]. A recent study demonstrated that TMS over SI selectively reduced the typical corticospinal mapping of biomechanically impossible movements [Fadiga et al, 1995[Fadiga et al, , 2005Romani et al, 2005], which were associated with aversive somatic feelings, without impacting mirror responses to possible movements that did not evoke somatic feelings in the observer.…”

Increased Resting-State Gamma-Band Connectivity in First-Episode Schizophrenia

“…This role is not limited to neural synchrony of local brain networks, but also extends to large-scale interactions. [40][41][42][43] Therefore, investigations of connectivity, rather than power, in the resting state might contribute to disentangling the discrepancies of previous research, providing new insights into the role of gamma-band connectivity in the pathophysiology of the disorder. So far, only 2 studies have assessed gamma-band synchronization in patients with schizophrenia.…”

Pain processing in multisensory environments

“…Thus, this mechanism may also be important for multisensory interactions contributing to pain perception. First evidence supporting this assumption derives from the study by Betti et al [2], who reported enhanced functional coupling between primary sensory and motor cortex through neural coherence in the gamma band when participants are presented with needle-penetrating-hand clips. Thus, we suggest that the examination of oscillatory activity is a promising research target for future studies on pain processing in multisensory environments.…”

“…A more recent MEG study further investigated the effect of observing painful events on neuronal processing within the pain matrix [2]. The authors addressed the interplay of somatosensory and motor areas during the presentation of needlepenetrating-hand clips.…”