The influence of posterior parietal cortex on extrastriate visual activity: A concurrent TMS and fast optical imaging study. (November 2015)

• Record Type: Journal Article
• Authors: Parks, Nathan A.; Mazzi, Chiara; Tapia, Evelina; Savazzi, Silvia; Fabiani, Monica; Gratton, Gabriele; Beck, Diane M.
• Is Part Of: Neuropsychologia. Volume 78(2015)
• Page Start: 153
• Page End: 158
• Publication Date: 2015-11
• Subjects: Brain connectivity -- Transcranial magnetic stimulation (TMS) -- Near-infrared optical imaging -- Event-related optical signal (EROS) -- Posterior parietal cortex -- Phosphene; Neuropsychology -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Neuropsychologie -- Périodiques; Neuropsychology; Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.neuropsychologia.2015.10.002
• Languages: English
• ISSNs: 0028-3932

Abstract

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) 24–48 ms 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. Highlights: The functional connectivity between PPC and visual cortices was examined. TMS and event-related fast optical imaging (EROS) were used concurrently. EROS was used to image the spread of TMS-induced activity to occipital cortex. Activation of extrastriate visual cortex was found 24–48 ms following TMS.