Phase coding in the visual system: neuronal processing coordinated by brain oscillations (360G-Wellcome-207550_Z_17_Z)

The visual system receives a wealth of information of which only little is processed. My aim is to uncover the mechanisms involved in prioritizing information processing of visual scenes. To this end, I will test a novel hypothesis that explicitly predicts how brain oscillations serve to prioritize the flow of sensory information. The core idea is that neuronal oscillations serve to coordinate computations by organizing a temporal code. The theoretical framework predicts that alpha (8–13 Hz) oscillations support a ‘phase coding scheme’ in which a set of neuronal representations will activate sequentially within an alpha cycle. This mechanism serves to convert a complex visual scene into a temporal code: a ‘to-do list’ that can be processed sequentially by downstream regions. Spatial attention and saliency will determine the order in the list by differentially biasing the excitability of the individual representations. I will test this framework using intracranial recordings and magnetoencephalography (MEG) in combination with a new approach: ‘rapid frequency tagging’. Using a novel approach for visual entrainment of the alpha rhythm, I will test the model causally. The mechanism may generalize to brain networks beyond the visual system, thereby providing a general principle for neuronal coding and inter-regional communication.