title: Primary somatosensory contribution to action observation brain activity-combining fMRI and cTBS.
abstract: Traditionally the mirror neuron system (MNS) only includes premotor and posterior parietal cortices. However, somatosensory cortices, BA1/2 in particular, are also activated during action execution and observation. Here, we examine whether BA1/2 and the parietofrontal MNS integrate information by using functional magnetic resonance imaging (fMRI)-guided continuous theta-burst stimulation (cTBS) to perturb BA1/2. Measuring brain activity using fMRI while participants are under the influence of cTBS shows local cTBS effects in BA1/2 varied, with some participants showing decreases and others increases in the BOLD response to viewing actions vs control stimuli. We show how measuring cTBS effects using fMRI can harness this variance using a whole-brain regression. This analysis identifies brain regions exchanging action-specific information with BA1/2 by mapping voxels away from the coil with cTBS-induced, action-observation-specific BOLD contrast changes that mirror those under the coil. This reveals BA1/2 exchanges action-specific information with premotor, posterior parietal and temporal nodes of the MNS during action observation. Although anatomical connections between BA1/2 and these regions are well known, this is the first demonstration that these connections carry action-specific signals during observation and hence, that BA1/2 plays a causal role in the human MNS.
authors.affiliation: Department of Neuroscience, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 2, 9713 AW Groningen, The Netherlands.
authors.forename: Nikola
authors.initials: N
authors.lastname: Valchev
authors.affiliation: Department of Neuroscience, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 2, 9713 AW Groningen, The Netherlands The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Meibergdreef 47, 1105 BA Amsterdam, The Netherlands Department of Psychology, University of Amsterdam, Weesperplein 4, 1018 XA Amsterdam, The Netherlands v.gazzola@nin.knaw.nl.
authors.forename: Valeria
authors.initials: V
authors.lastname: Gazzola
authors.affiliation: Department of Psychology and Centro studi e ricerche in Neuroscienze Cognitive, University of Bologna, Cesena Campus, Cesena 47521, Italy, Istituto di Ricerca e Cura a Carattere Scientifico Fondazione Santa Lucia, Rome 00179, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Avenanti
authors.affiliation: Department of Neuroscience, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 2, 9713 AW Groningen, The Netherlands The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Meibergdreef 47, 1105 BA Amsterdam, The Netherlands Department of Psychology, University of Amsterdam, Weesperplein 4, 1018 XA Amsterdam, The Netherlands.
authors.forename: Christian
authors.initials: C
authors.lastname: Keysers
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D059167:Mirror Neurons / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: BA1/2; SI; TMS; action observation; mirror neuron system