Task and Regions Specific Top-Down Modulation of Alpha Rhythms in Parietal Cortex.
Alpha (8-12 Hz) power desynchronization is strongly associated to visual perception but has been observed in a large variety of tasks, indicating a general role in task anticipation. We previously reported in human observers that interference by repetitive transcranial magnetic stimulation (rTMS) of core regions of the dorsal attention network (DAN) disrupts both anticipatory alpha desynchronization and performance during a visuospatial attention (VSA) task. Here, we test the hypothesis that alpha desynchronization is task specific, and can be selectively modulated by interfering with activity in different higher-order parietal regions. We contrast the effects of rTMS on alpha rhythms and behavior on 2 different tasks: a VSA and a semantic decision task, by targeting the posterior intraparietal sulcus (pIPS), a core region of the DAN, or the angular gyrus (AG), a core region of the default mode network (DMN). We found that both performance and anticipatory alpha desynchronization were affected by stimulation of IPS only during VSA, and of AG only during semantic decisions. These findings indicate the existence of multiple dedicated parietal channels for the modulation of anticipatory alpha rhythms, which in turn reflect task-specific modulation of excitability in human parieto-occipital cortex.
Department of Neuroscience, Imaging, and Clinical Science, Institute of Advanced Biomedical Technologies (ITAB), University "G. D'Annunzio", Via dei Vestini 33, Chieti 66100, Italy.
Paolo
P
Capotosto
Department of Neuroscience, Imaging, and Clinical Science, Institute of Advanced Biomedical Technologies (ITAB), University "G. D'Annunzio", Via dei Vestini 33, Chieti 66100, Italy.
Antonello
A
Baldassarre
Department of Neuroscience, Imaging, and Clinical Science, Institute of Advanced Biomedical Technologies (ITAB), University "G. D'Annunzio", Via dei Vestini 33, Chieti 66100, Italy.
Carlo
C
Sestieri
Department of Neuroscience, Imaging, and Clinical Science, Institute of Advanced Biomedical Technologies (ITAB), University "G. D'Annunzio", Via dei Vestini 33, Chieti 66100, Italy.
Sara
S
Spadone
Department of Neuroscience, Imaging, and Clinical Science, Institute of Advanced Biomedical Technologies (ITAB), University "G. D'Annunzio", Via dei Vestini 33, Chieti 66100, Italy.
Gian Luca
GL
Romani
Department of Neurology, Radiology, Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63130, USA.
Maurizio
M
Corbetta
D000513:Alpha Rhythm / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D009778:Occipital Lobe / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D014796:Visual Perception / Q000502:physiology
anticipatory alpha; parietal cortex; rTMS; semantic decision; visuospatial attention