From simulation to reciprocity: The case of complementary actions

Abstract

A large body of research reports that perceiving body movements of other people activates motor representations in the observer's brain. This automatic resonance mechanism appears to be imitative in nature. However, action observation does not inevitably lead to symmetrical motor facilitation: Mirroring the observed movement might be disadvantageous for successfully performing joint actions. What remains unknown is how we are to resolve the possible conflict between the automatic tendency to "mirror" and the need to perform different context-related complementary actions. By using single-pulse transcranial magnetic stimulation, we found that observation of a double-step action characterized by an implicit complementary request engendered a shift from symmetrical simulation to reciprocity in the participants' corticospinal activity. Accordingly, differential motor facilitation was revealed for the snapshots evoking imitative and complementary gestures despite the fact that the observed type of grasp was identical. Control conditions in which participants observed the same action sequence but in a context not implying a complementary request were included as well. The results provide compelling evidence that when an observed action calls for a nonidentical complementary action, an interplay between the automatic tendency to resonate with what is observed and to implicitly prepare for the complementary action does emerge. In other words, implicit complementary requests might have the ability to draw attention to specific features of the context affording nonidentical responses.

The multiform motor cortical output: Kinematic, predictive and response coding

“…A finding in accordance with behavioral (Bertenthal, Longo, & Kosobud, 2006;Liepelt et al, 2010) and neurophysiological (Press, Bird, Walsh, & Heyes, 2008) studies showing motor facilitation effects for transitive as well as intransitive actions . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 15 Moreover, the present findings extends previous evidence on response preparation in hand muscles (Newman-Norlund, Noordzij, Meulenbroek, & Bekkering, 2007;Ocampo & Kritikos, 2010;Sartori, Cavallo, Bucchioni, & Castiello, 2011b, 2012bSartori, Betti, & Castiello, 2013a, 2013bSartori et al, 2013c) showing a modulation of CS excitability also when the observed action calls for a gesture involving different body parts with respect to the observed ones. In the present study, observers' upper limb muscles were activated while observing a soccer player kicking a ball straight in their direction.…”

“…It is our contention that motor resonance's role is to maintain a functional trace of an observed action in order to facilitate selection between alternatives when there are a variety of possible responses (Sartori et al, 2012b(Sartori et al, , 2012c(Sartori et al, , 2013b. Running different coding levels while processing the observed action would be helpful to prepare an correct reaction (Bekkering et al, 2009).…”

Corticospinal Excitability Modulation During Action Observation

“…During the experiments carried out, modulation of corticospinal excitability was a reliable, indirect measure of the capacity to activate appropriate motor programs in an interactive context. Previous studies utilizing the TMS/MEP technique have shown that corticospinal activation resulting from action observation does not invariably possess an imitative bias but, depending on contextual factors, can also prime motor activation for complementary actions 29,30 . Single-pulse TMS studies have demonstrated that observing a two-step action sequence in which a complementary request is embedded prompts a switch from emulation to responsiveness in the participants' corticospinal activity.…”

“…In this respect, some researchers showed that the automatic effects of mirroring can be abolished following incompatible training: mirror and counter-mirror responses seem to follow the same timecourse 27,28 . Interestingly, in contrast to previous studies, MEPs induced by spTMS were recently used to assess spontaneous corticospinal activation while video-clips evoking emulative or nonidentical complementary gestures were being simply observed 29,30 . Results showed a natural switch from an emulative to a context-related action in corticospinal activity.…”

The Aesthetic Stance: On the conditions and consequences of becoming a beholder

“…19 Newman-Norlund et al 2007, Fuljii, Hihara & Iriki (2007) & Sartori et al (2011. See also Brincker ( , 2012 for an analysis of the problems with the classic mirror neuron interpretations and arguments for the alternative "social affordance" hypothesis.…”