Poster Session E, Monday, March 25, 2:30 – 4:30 pm, Pacific Concourse
Functional dissociation of EEG theta rhythms between prefrontal and visual cortices and their synchronization during sustained attention
Hio-Been Han1,2, Ka Eun Lee1,3, Jee Hyun Choi1,4; 1Korea Institute of Science and Technology, 2Korea Advanced Institute of Science and Technology, 3Seoul National University, 4Korea University of Science and Technology
Previous literature has identified the importance of a coherent oscillatory network between distal brain regions contributing to task performance, such as the fronto-visual theta (4-12 Hz) network. However, the conceptual framework has been challenged by recent evidence which suggests region-specifically different functions of cortical theta rhythms, especially those in the prefrontal cortex (PFC) and the visual cortex (VC). Because of their opposite functional correlates against attention, as PFC theta correlates while VC theta anti-correlates with attention, the underlying principle behind their functional network during sustained attention remains poorly understood. Here, we show that PFC/VC theta are different neuronal entities having distinct functional correlates, so that their connectivity increases during sustained attention when one (i.e., visual) is suppressed. Analyzing EEG signals from mouse brain during Go/No-Go task, we found PFC (VC) theta was stronger (weaker) in good-performance epochs than in bad-performance epochs. Interestingly, the synchronization between two oscillations increased during the epochs with good performance, despite the suppression of theta in VC. The fronto-visual phase-coherent theta network showed a predominant posterior-to-anterior direction on the order of few milliseconds. Along with the improved synchrony, the delay showed a subtle but systematic decrease, suggesting a boost of information relay from the posterior to the anterior brain region. Our findings not only provide empirical evidence for the distinction between the theta of PFC and VC, but also reveal the overlooked aspect of long-range synchrony between functionally different oscillators in the cerebral cortex.
Topic Area: EXECUTIVE PROCESSES: Monitoring & inhibitory control