Left posterior parietal theta burst stimulation affects gestural imitation regardless of semantic content.
OBJECTIVE
Neuro-imaging studies have suggested that the ability to imitate meaningless and meaningful gestures may differentially depend on superior (SPL) and inferior (IPL) parietal lobule. Therefore, we hypothesized that imaging-guided neuro-navigated continuous theta burst stimulation (cTBS) over left SPL mainly affects meaningless and over left IPL predominantly meaningful gestures.


METHODS
Twelve healthy subjects participated in this study. High resolution structural MRI was used for imaging guided neuro-navigation cTBS. Participants were targeted with one train of cTBS in three experimental sessions: sham stimulation over vertex and real cTBS over left SPL and IPL, respectively. An imitation task, including 24 meaningless and 24 meaningful gestures, was performed 'offline'.


RESULTS
cTBS over both left IPL and SPL significantly interfered with gestural imitation. There was no differential effect of SPL and IPL cTBS on gesture type (meaningless versus meaningful).


CONCLUSIONS
Our findings confirm that left posterior parietal cortex plays a predominant role in gestural imitation. However, the hypothesis based on the dual route model suggesting a differential role of SPL and IPL in the processing of meaningless and meaningful gestures could not be confirmed.


CONCLUSIONS
Left SPL and IPL play a common role within the posterior-parietal network in gestural imitation regardless of semantic content.
Perception and Eye Movement Laboratory, Department of Neurology, Inselspital, University Hospital Bern, Switzerland; Perception and Eye Movement Laboratory, Department of Clinical Research, Inselspital, University Hospital Bern, Switzerland.
Tim
T
Vanbellingen
Perception and Eye Movement Laboratory, Department of Neurology, Inselspital, University Hospital Bern, Switzerland; Perception and Eye Movement Laboratory, Department of Clinical Research, Inselspital, University Hospital Bern, Switzerland.
Manuel
M
Bertschi
Perception and Eye Movement Laboratory, Department of Neurology, Inselspital, University Hospital Bern, Switzerland; Perception and Eye Movement Laboratory, Department of Clinical Research, Inselspital, University Hospital Bern, Switzerland; Neurology and Neurorehabilitation Center, Luzerner Kantonsspital, Switzerland.
Thomas
T
Nyffeler
Nuffield Department of Clinical Neurosciences, Clinical Neurology, University of Oxford, Oxford, United Kingdom.
Dario
D
Cazzoli
Institute of Diagnostic and Interventional Neuroradiology, Inselspital, University Hospital Bern, Switzerland.
Roland
R
Wiest
Department of Neurology, Inselspital, University Hospital Bern, Switzerland.
Claudio
C
Bassetti
Movement Disorders Centre, Department of Neurology, Inselspital, University Hospital Bern, Switzerland.
Alain
A
Kaelin-Lang
Perception and Eye Movement Laboratory, Department of Neurology, Inselspital, University Hospital Bern, Switzerland; Perception and Eye Movement Laboratory, Department of Clinical Research, Inselspital, University Hospital Bern, Switzerland.
René
R
Müri
Perception and Eye Movement Laboratory, Department of Neurology, Inselspital, University Hospital Bern, Switzerland; Perception and Eye Movement Laboratory, Department of Clinical Research, Inselspital, University Hospital Bern, Switzerland; Neurology and Neurorehabilitation Center, Luzerner Kantonsspital, Switzerland. Electronic address: stephan.bohlhalter@luks.ch.
Stephan
S
Bohlhalter
D000328:Adult; D005260:Female; D005868:Gestures; D006801:Humans; D007100:Imitative Behavior / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000502:physiology*; D013826:Theta Rhythm; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult
Gestures; IPL; Imitation; SPL; Theta burst stimulation