TOP-DOWN INFLUENCE ON EARLY VISUAL PROCESSING BY AN ANTICIPATORY LARGE-SCALE NETWORK IN MACAQUE PREFRONTAL CORTEX

S.L.Bressler; H.Liang; M.Ding

CCSBS, FAU, Boca Raton, FL, USA

The prefrontal cortex is involved in many executive functions, including anticipation. Prefrontal activity may tune neural populations in sensory areas for rapid stimulus and response processing. Several studies have related the level of rhythmic synchronization at different frequencies during anticipatory periods to the amplitude and latency of early event-related potential (ERP) components and reaction time (RT); some have implicated the prefrontal cortex in anticipatory processing. However, evidence on the organization of anticipatory prefrontal activity, and on whether the prefrontal cortex exerts anticipatory top-down effects on sensory areas, has not been available. To address these questions, we performed power, coherence and DTF (measuring causal influence) spectral analysis on local field potentials simultaneously recorded at distributed sites in one hemisphere of a macaque monkey performing a visual pattern discrimination task. The measures were computed in trial sets rank ordered by RT. During the prestimulus period, we found a distributed prefrontal network synchronized in the beta frequency range. Network power and coherence varied inversely with RT, suggesting an anticipatory function, and were correlated with N1 peak amplitude and latency of ERPs in visual areas, suggesting an effect on stimulus processing. A prefrontal top-down influence on stimulus processing was suggested by the correlation of prestimulus prefrontal-to-visual DTF with N1 peak amplitude and latency at the same visual sites. The results imply that large-scale prefrontal networks exert anticipatory bias on visual cortical areas to facilitate their stimulus processing. Supported by: NSF, NIMH, ONR