Overt orienting of spatial attention and corticospinal excitability during action observation are unrelated.
Observing moving body parts can automatically activate topographically corresponding motor representations in the primary motor cortex (M1), the so-called direct matching. Novel neurophysiological findings from social contexts are nonetheless proving that this process is not automatic as previously thought. The motor system can flexibly shift from imitative to incongruent motor preparation, when requested by a social gesture. In the present study we aim to bring an increase in the literature by assessing whether and how diverting overt spatial attention might affect motor preparation in contexts requiring interactive responses from the onlooker. Experiment 1 shows that overt attention-although anchored to an observed biological movement-can be captured by a target object as soon as a social request for it becomes evident. Experiment 2 reveals that the appearance of a short-lasting red dot in the contralateral space can divert attention from the target, but not from the biological movement. Nevertheless, transcranial magnetic stimulation (TMS) over M1 combined with electromyography (EMG) recordings (Experiment 3) indicates that attentional interference reduces corticospinal excitability related to the observed movement, but not motor preparation for a complementary action on the target. This work provides evidence that social motor preparation is impermeable to attentional interference and that a double dissociation is present between overt orienting of spatial attention and neurophysiological markers of action observation.
Dipartimento di Psicologia Generale, Università di Padova, Padova, Italy.
Sonia
S
Betti
Dipartimento di Psicologia Generale, Università di Padova, Padova, Italy.|Center for Cognitive Neuroscience, Università di Padova, Padova, Italy.|Centro Beniamino Segre, Accademia Nazionale dei Lincei, Roma, Italy.
Umberto
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Castiello
Dipartimento di Psicologia Generale, Università di Padova, Padova, Italy.
Silvia
S
Guerra
Dipartimento di Psicologia Generale, Università di Padova, Padova, Italy.|Center for Cognitive Neuroscience, Università di Padova, Padova, Italy.
Luisa
http://orcid.org/0000-0002-3838-8958
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Sartori
D000328:Adult; D001288:Attention / Q000502:physiology*; D004576:Electromyography; D019054:Evoked Potentials, Motor; D053483:Eye Movement Measurements; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D010775:Photic Stimulation; D011712:Pyramidal Tracts / Q000502:physiology*; D013028:Space Perception / Q000502:physiology; D050781:Transcranial Magnetic Stimulation; D014741:Video Recording; D055815:Young Adult