title: The Influence of Alertness on the Spatial Deployment of Visual Attention is Mediated by the Excitability of the Posterior Parietal Cortices.
abstract: With a reduced level of alertness, healthy individuals typically show a rightward shift when deploying visual attention in space. The impact of alertness on the neural networks governing visuospatial attention is, however, poorly understood. By using a transcranial magnetic stimulation twin-coil approach, the present study aimed at investigating the effects of an alertness manipulation on the excitability of the left and the right posterior parietal cortices (PPCs), crucial nodes of the visuospatial attentional network. Participants' visuospatial attentional deployment was assessed with a free visual exploration task and concurrent eye tracking. Their alertness level was manipulated through the time of the day, that is, by testing chronotypically defined evening types both during their circadian on- and off-peak times. The results revealed an increased excitability of the left compared with the right PPC during low alertness. On the horizontal dimension, these results were accompanied by a significant rightward shift in the center and a bilateral narrowing in the periphery of the visual exploration field, as well as a central upward shift on the vertical dimension. The findings show that the manipulation of non-spatial attentional aspects (i.e., alertness) can affect visuospatial attentional deployment and modulate the excitability of areas subtending spatial attentional control.
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Paladini
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland.|Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.|Division of Cognitive and Restorative Neurology, Department of Neurology, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.|Center for Cognition, Learning and Memory, University of Bern, Bern, Switzerland.
authors.forename: René M
authors.initials: RM
authors.lastname: Müri
authors.affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.|Division of Cognitive and Restorative Neurology, Department of Neurology, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.
authors.forename: Jurka
authors.initials: J
authors.lastname: Meichtry
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland.|ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
authors.forename: Tobias
authors.initials: T
authors.lastname: Nef
authors.affiliation: Center for Cognition, Learning and Memory, University of Bern, Bern, Switzerland.|Department of Psychology, University of Bern, Bern, Switzerland.
authors.forename: Fred W
authors.initials: FW
authors.lastname: Mast
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland.|ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.|University Hospital of Old Age Psychiatry, University of Bern, Bern, Switzerland.
authors.forename: Urs P
authors.initials: UP
authors.lastname: Mosimann
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland.|Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.|Center of Neurology and Neurorehabilitation, Luzerner Kantonsspital, Lucerne, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Nyffeler
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland.|ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
authors.forename: Dario
authors.initials: D
authors.lastname: Cazzoli
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D000071080:Cortical Excitability / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D008297:Male; D010296:Parietal Lobe / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
keywords: alertness; eye tracking; posterior parietal cortex (PPC); transcranial magnetic stimulation (TMS); visuospatial attention