Electrocortical signatures of detecting errors in the actions of others: An EEG study in pianists, non-pianist musicians and musically naïve people.

Detecting others' action errors plays a critical role in social life. Studies indicate that executing action errors and observing other's errors activate a specific cerebral system specialized for performance monitoring and detecting mismatches between an internal model of the action and the executed/observed one. Such a system may be particularly important for highly skilled performance. By recording electro-encephalographic (EEG) activity in expert pianists, non-pianist musicians and musically naïve individuals while they observed correct or incorrect mute piano sequences, we explored the link between sensorimotor expertise, the ability to detect another's erroneous action (indexed by positivity error, Pe) and action simulation (indexed by mu frequency suppression). Superior error detection in pianists was paralleled by a larger Pe, hinting at the selective activation of the parietal error-monitoring system in visuo-motor experts. Moreover, only in pianists did action observation induce left lateralized mu suppression in the 10-12 Hz band, reflecting somatotopic sensorimotor simulation. A mediation analysis showed that mu suppression and performance (indexed by d') were mediated by Pe amplitude, indicating that the higher the simulation, the higher the sensitivity to errors for large Pe amplitude. This study shows that specific electrocortical indices link motor simulation and detection of errors in the actions of others.

Influence of warmth and competence on the promotion of safe in-group selection: Stereotype content model and social categorization of faces.

Categorizing an individual as a friend or foe plays a pivotal role in navigating the social world. According to the stereotype content model (SCM), social perception relies on two fundamental dimensions, warmth and competence, which allow us to process the intentions of others and their ability to enact those intentions, respectively. Social cognition research indicates that, in categorization tasks, people tend to classify other individuals as more likely to belong to the out-group than the in-group (in-group overexclusion effect, IOE) when lacking diagnostic information, probably with the aim of protecting in-group integrity. Here, we explored the role of warmth and competence in group-membership decisions by testing 62 participants in a social-categorization task consisting of 150 neutral faces. We assessed whether (a) warmth and competence ratings could predict the in-group/out-group categorization, and (b) the reliance on these two dimensions differed in low-IOE versus high-IOE participants. Data showed that high ratings of warmth and competence were necessary to categorize a face as in-group. Moreover, while low-IOE participants relied on warmth, high-IOE participants relied on competence. This finding suggests that the proneness to include/exclude unknown identities in/from one's own in-group is related to individual differences in the reliance on SCM social dimensions. Furthermore, the primacy of the warmth effect seems not to represent a universal phenomenon adopted in the context of social evaluation.

Pain sensitivity in mice lacking the Ca(v)2.1alpha1 subunit of P/Q-type Ca2+ channels.

The role of voltage-gated Ca(2+) (Ca(V)) channels in pain mechanisms has been the object of intense investigation using pharmacological approaches and, more recently, using mutant mouse models lacking the Ca(V)alpha(l) pore-forming subunit of N-, R- and T-type channels. The role of P/Q-type channels in nociception and pain transmission has been investigated by pharmacological approaches but remains to be fully elucidated. To address this issue, we have analyzed pain-related behavioral responses of null mutant mice for the Ca(V)2.1alpha(1) subunit of P/Q-type channels. Homozygous null mutant Ca(V)2.1alpha(1)-/- mice developed dystonia at 10-12 days after birth and did not survive past weaning. Tested at ages where motor deficit was either absent or very mild, Ca(V)2.1alpha(1)-/- mice showed reduced tail withdrawal latencies in the tail-flick test and reduced abdominal writhes in the acetic acid writhing test. Adult heterozygous Ca(V)2.1alpha(1)+/- mice did not show motor deficits in the rotarod and activity cage tests and did not show alterations in pain responses in the tail-flick test and the acetic acid writhing test. Strikingly, they showed a reduced licking response during the second phase of formalin-induced inflammatory pain and a reduced mechanical allodynia in the chronic constriction injury model of neuropathic pain. Our findings show that P/Q-type channels play an antinociceptive role in sensitivity to non-injurious noxious thermal stimuli and a pronociceptive role in inflammatory and neuropathic pain states, pointing to an important role of Ca(V)2.1 channels in central sensitization.