Left hemisphere dominance in reading the sensory qualities of others’ pain?

Abstract

Seeing or imagining others in pain may activate both the sensory and affective components of the neural network (pain matrix) that is activated during the personal experience of pain. Transcranial magnetic stimulation (TMS), proved adept at highlighting the sensorimotor side of empathy for pain in studies where mere observation of needles penetrating body parts of a human model brought about a clear corticospinal motor inhibition. By using TMS, we investigated whether inferring the sensory properties of the pain of a model influenced the somatomotor system of an onlooker. Moreover, we tested the possible lateralization of the motor substrates underlying this reading process. We recorded motor-evoked potentials (MEPs) to left and right motor cortex stimulation during the observation of "flesh and bone" painful stimulations of right and left hands respectively. We found a significant reduction of onlookers' MEPs amplitudes specific to the muscle penetrated in the model. Subjective inferences about localization and intensity of the observed pain were associated with specific patterns of motor modulation with larger inhibitory effects following stimulation of the left motor cortex. Thus, results indicate that the mental simulation of the sensory qualities of others' pain may be lateralized to the left hemisphere.

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

“…While there is ample consensus that both the affective and the sensorimotor node of the pain matrix can be recruited during the vicarious experience of pain (Hein and Singer, 2008), we focused on the possible role of primary sensory and motor cortex in empathic pain mapping. Importantly, these regions seem to be specifically involved in the observation of flesh and bone pain stimuli delivered to body parts of stranger individuals (Avenanti et al, 2005Bufalari et al, 2007;Fecteau et al, 2008;Minio-Paluello et al, 2006, 2009. The involvement of sensorimotor regions in the empathic mapping of others' pain is in keeping with TMS (Avenanti et al, 2005Minio-Paluello et al, 2006), somatosensory (Bufalari et al, 2007) and laser-evoked potentials (Valeriani et al, 2008) studies.…”

“…Importantly, these regions seem to be specifically involved in the observation of flesh and bone pain stimuli delivered to body parts of stranger individuals (Avenanti et al, 2005Bufalari et al, 2007;Fecteau et al, 2008;Minio-Paluello et al, 2006, 2009. The involvement of sensorimotor regions in the empathic mapping of others' pain is in keeping with TMS (Avenanti et al, 2005Minio-Paluello et al, 2006), somatosensory (Bufalari et al, 2007) and laser-evoked potentials (Valeriani et al, 2008) studies. However, the main point of novelty of our study is that the essence of empathic mapping of observed pain resides in the dynamic cross-talk between somato-motor regions much more than on their separate neural activity.…”

“…Relevant to the present study is a recent MEG report showing that pain-induced ␥ oscillations in primary somatosensory cortices are specifically related to the subjective pain experience instead than to the objective attributes of painful stimuli such as their actual intensity (Gross et al, 2007). Somatosensory evoked potential (SEP) and transcranial magnetic stimulation (TMS) studies show that primary somatosensory (SI) (Bufalari et al, 2007) and motor (MI) (Avenanti et al, 2005Fecteau et al, 2008;Minio-Paluello et al, 2006, 2009 cortices are involved in the direct observation of pain stimuli delivered to stranger individuals. However, no studies have so far investigated whether empathic pain mapping is linked to the construction of a functional SI-MI network.…”

The pain of a model in the personality of an onlooker: Influence of state-reactivity and personality traits on embodied empathy for pain

“…These onlookers' 'mirror-like' inhibitory corticospinal responses are specific to the body part stimulated in the model and correlate with the evaluation of spread and intensity (but not of the unpleasantness) of the pain ascribed to the model (Avenanti et al, 2005Minio-Paluello et al, 2006); thus, the inhibition likely reflects the simulation of basic sensory features of others' pain (intensity, diffusion, localization of pain) (Avenanti et al, 2005). In a similar vein, somatosensory-evoked potentials (SEPs, Bufalari et al, 2007), laser-evoked potentials (LEPs, Valeriani et al, 2008), magnetoencephalography (MEG, Cheng et al, 2008a) and neuroimaging studies (Jackson et al, 2006;Saarela et al, 2007;Moriguchi et al, 2007;Cheng et al, 2007;Lamm et al, 2007a;Lamm et al, 2007b;Benuzzi et al, 2008) indicate specific pain-related activity into the observers' somatomotor system during empathy for pain.…”

“…Video clips showed: (i) the static view of the dorsal surface of a right hand of a stranger male model depicted from a first-person view point; (ii) a needle deeply penetrating the FDI muscle of the same hand (Avenanti et al, 2005Minio-Paluello et al, 2006). To minimize habituation, three different versions of the stimuli were presented.…”