title: The influence of posterior parietal cortex on extrastriate visual activity: A concurrent TMS and fast optical imaging study.
abstract: The posterior parietal cortex (PPC) is a critical node in attentional and saccadic eye movement networks of the cerebral cortex, exerting top-down control over activity in visual cortex. Here, we sought to further elucidate the properties of PPC feedback by providing a time-resolved map of functional connectivity between parietal and occipital cortex using single-pulse TMS to stimulate the left PPC while concurrently recording fast optical imaging data from bilateral occipital cortex. Magnetic stimulation of the PPC induced transient ipsilateral occipital activations (BA 18) 24-48ms post-TMS. Concurrent TMS and fast optical imaging results demonstrate a clear influence of PPC stimulation on activity within human extrastriate visual cortex and further extend this time- and space-resolved method for examining functional connectivity.
authors.affiliation: University of Arkansas, United States. Electronic address: naparks@uark.edu.
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Parks
authors.affiliation: University of Verona, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Mazzi
authors.affiliation: University of Illinois, Urbana-Champaign, United States; Beckman Institute for Advanced Science and Technology, United States.
authors.forename: Evelina
authors.initials: E
authors.lastname: Tapia
authors.affiliation: University of Verona, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Savazzi
authors.affiliation: University of Illinois, Urbana-Champaign, United States; Beckman Institute for Advanced Science and Technology, United States.
authors.forename: Monica
authors.initials: M
authors.lastname: Fabiani
authors.affiliation: University of Illinois, Urbana-Champaign, United States; Beckman Institute for Advanced Science and Technology, United States.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Gratton
authors.affiliation: University of Illinois, Urbana-Champaign, United States; Beckman Institute for Advanced Science and Technology, United States.
authors.forename: Diane M
authors.initials: DM
authors.lastname: Beck
mesh_terms: D005071:Evoked Potentials; D025461:Feedback, Physiological; D006801:Humans; D009778:Occipital Lobe / Q000502:physiology; D061848:Optical Imaging; D010296:Parietal Lobe / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D014795:Visual Pathways / Q000502:physiology*
keywords: Brain connectivity; Event-related optical signal (EROS); Near-infrared optical imaging; Phosphene; Posterior parietal cortex; Transcranial magnetic stimulation (TMS)