title: Familiarity modulates motor activation while other species' actions are observed: a magnetic stimulation study.
abstract: Observing other people's actions facilitates the observer's motor system as compared with observing the same individuals at rest. This motor activation is thought to result from mirror-like activity in fronto-parietal areas, which enhances the excitability of the primary motor cortex via cortico-cortical pathways. Although covert motor activation in response to observed actions has been widely investigated between conspecifics, how humans cope with other species' actions has received less attention. For example, it remains unclear whether the human motor system is activated by observing other species' actions, and whether prior familiarity with the non-conspecific agent modulates this activation. Here, we combined single-pulse transcranial magnetic stimulation and motor-evoked potential recording to explore the impact of familiarity on motor activation during the observation of non-conspecific actions. Videos displaying actions performed either by a conspecific (human) or by a non-conspecific (dog) were shown to individuals who had prior familiarity or no familiarity at all with the non-conspecific agent. We found that, whereas individuals with long-lasting familiarity showed similar levels of motor activation for human and canine actions, individuals who had no familiarity showed higher motor activation for human than for canine actions. These findings suggest that the human motor system is flexible enough to resonate with other species, and that familiarity plays a key role in tuning this ability.
authors.affiliation: Laboratory of Cognitive Neuroscience, Department of Human Sciences, University of Udine, via Margreth 3, I-33100, Udine, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Amoruso
authors.affiliation: Laboratory of Cognitive Neuroscience, Department of Human Sciences, University of Udine, via Margreth 3, I-33100, Udine, Italy.|Polo Friuli Venezia Giulia, Scientific Institute (IRRCS) Eugenio Medea, Udine, Italy.|School of Psychology, Bangor University, Bangor, Wales, UK.
authors.forename: Cosimo
authors.initials: C
authors.lastname: Urgesi
mesh_terms: D000328:Adult; D000818:Animals; D001921:Brain / Q000502:physiology*; D004285:Dogs; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual; D011597:Psychomotor Performance; D013045:Species Specificity; D050781:Transcranial Magnetic Stimulation
keywords: action observation; corticospinal excitability; familiarity; non-conspecifics; transcranial magnetic stimulation