In daily life, we receive a continuous stream of information. This sensory input must be filtered, processed, integrated, stored and retrieved when relevant, while irrelevant or distracting input must be suppressed.
Think for instance of biking down a busy street, paying attention to traffic around you while ignoring a barking dog on the sidewalk. The brain constantly makes decisions based on perceptual input; quickly weighing and processing information, resulting in goal-directed behaviour. This is a pretty impressive feat, requiring the coordination of multiple operations on a sub-millisecond time-scale. For instance, the environment must be sampled, and the right connections between brain areas must be established at the right moment. However, large gaps exist in our understanding of the neural mechanisms underlying these dynamic interactions. The overall aim of our research program is to elucidate how the brain sets up the functional neural architecture involved in perceptual processing. Our working hypothesis is that neuronal oscillations play a critical role in controlling the flow of information through the brain, such that specific brain rhythms perform low-level mechanistic operations, forming the foundation for cognition.
In this view, oscillations provide the scaffolding for information processing: selectively sampling sensory inputs, disengaging task-irrelevant areas, and temporarily connecting relevant nodes such that efficient and effective exchange of information can take place. Considering the sheer number of brain cells and their anatomical connections, this is not a trivial task. The oscillatory building blocks we focus on, and their proposed mechanistic roles, are: (A) slow oscillations in the delta/theta bands (1–7 Hz), providing selective sampling of sensory input, (B) the alpha rhythm (8–14 Hz), involved in active functional inhibition, and (C) beta oscillations (15–30 Hz), forming transient, flexible neural ensembles. Combined, these building blocks allow for the filtering of incoming information, and successfully routing this information—encoded in spike activity patterns—through the brain. We use a combination of MEG, ECoG, LFP & spike recordings, as well as psychophysics and computational modelling, to test these ideas at all critical levels.