Virtual: Brain meeting: Dr Andre Bastos

Brain meeting 

Abstract: To understand the neural basis of cognition, we must understand how top-down control of bottom-up sensory inputs is achieved. We have marshaled evidence for a canonical cortical control circuit that involves rhythmic interactions between different cortical layers. By performing multiple-area, multi-laminar recordings, we've found that local field potential (LFP) power in the gamma band (40-100 Hz) is strongest in superficial layers (layers 2/3), and LFP power in the alpha/beta band (8-30 Hz) is strongest in deep layers (layers 5/6). The gamma-band is strongly linked to bottom-up sensory processing and neuronal spiking carrying stimulus information, while the alpha/beta-band is linked to top-down processing. Deep layer alpha/beta projects to superficial layers, and is negatively coupled to gamma. These oscillations give rise to separate channels for neuronal communication: feedforward for the gamma-band, and feedback for the alpha/beta band. Attention, working memory, and prediction processing all involve modulation of gamma and alpha/beta synchronization, both within and across areas of the frontal/parietal/visual network. These rhythmic interactions breakdown during anesthesia-induced unconsciousness. Based on these observations, we hypothesize that the interplay between alpha/beta and gamma synchronization is a canonical mechanism to enable cognition and consciousness. My plan for future work is to causally test this hypothesis by manipulating these rhythms.