title: Changing the spatial scope of attention alters patterns of neural gain in human cortex.
abstract: Over the last several decades, spatial attention has been shown to influence the activity of neurons in visual cortex in various ways. These conflicting observations have inspired competing models to account for the influence of attention on perception and behavior. Here, we used electroencephalography (EEG) to assess steady-state visual evoked potentials (SSVEP) in human subjects and showed that highly focused spatial attention primarily enhanced neural responses to high-contrast stimuli (response gain), whereas distributed attention primarily enhanced responses to medium-contrast stimuli (contrast gain). Together, these data suggest that different patterns of neural modulation do not reflect fundamentally different neural mechanisms, but instead reflect changes in the spatial extent of attention.
authors.affiliation: Neurosciences Graduate Program and Department of Psychology, University of California, San Diego, La Jolla, California 92093-0109, and Departments of Psychology and Mathematics, Middlebury College, Middlebury, Vermont 05753.
authors.forename: Sirawaj
authors.initials: S
authors.lastname: Itthipuripat
authors.forename: Javier O
authors.initials: JO
authors.lastname: Garcia
authors.forename: Nuttida
authors.initials: N
authors.lastname: Rungratsameetaweemana
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Sprague
authors.forename: John T
authors.initials: JT
authors.lastname: Serences
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D055815:Young Adult