title: Spatial attention changes excitability of human visual cortex to direct stimulation.
abstract: Conscious perception depends not only on sensory input, but also on attention [1, 2]. Recent studies in monkeys [3-6] and humans [7-12] suggest that influences of spatial attention on visual awareness may reflect top-down influences on excitability of visual cortex. Here we tested this specifically, by providing direct input into human visual cortex via cortical transcranial magnetic stimulation (TMS) to produce illusory visual percepts, called phosphenes. We found that a lower TMS intensity was needed to elicit a conscious phosphene when its apparent spatial location was attended, rather than unattended. Our results indicate that spatial attention can enhance visual-cortex excitability, and visual awareness, even when sensory signals from the eye via the thalamic pathway are bypassed.
authors.affiliation: Institute of Neurology, Wellcome Department of Imaging Neuroscience, University College London, London WC1N 3BG, United Kingdom. s.bestmann@fil.ion.ucl.ac.uk
authors.forename: Sven
authors.initials: S
authors.lastname: Bestmann
authors.forename: Christian C
authors.initials: CC
authors.lastname: Ruff
authors.forename: Colin
authors.initials: C
authors.lastname: Blakemore
authors.forename: Jon
authors.initials: J
authors.lastname: Driver
authors.forename: Kai V
authors.initials: KV
authors.lastname: Thilo
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010719:Phosphenes / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D014793:Visual Cortex / Q000502:physiology*