Guest Lecture by Sophie Herbst
The human brain efficiently extracts the temporal structure of sensory environments to form temporal predictions. Temporal predictions then serve to orient attention in time, to enhance the reaction to and perceptual processing of sensory events occurring at the predicted moments.
An influential hypothesis, built on seminal work in non-human primates, holds that temporal predictions can find their implementation in neural oscillations, notably in the delta band (0.5 – 3 Hz): endogenous delta oscillations entrain to (periodic) temporal regularities of sensory inputs, thereby tuning the relevant brain processes to the most relevant moments in the sensory environment. Magneto- and electro-encephalography (M/EEG) based investigations in humans have further strengthened the relevance of delta oscillations for the processing of signals with temporal regularities. However, it remains a challenge to clearly separate endogenous oscillations from exogenously evoked brain responses to exogenous rhythms. Here, I will present recent work that supports a neural implementation of temporal predictions by delta oscillatory phase using EEG, albeit with differing observations in non-rhythmic versus rhythmic contexts. Furthermore, I will discuss an exploratory study in which we assessed spontaneous delta oscillations in human MEG recordings.
In sum, I argue that the functional role of neural oscillations for human implicit timing needs to be further spelled out, considering varying temporal contexts, and in combination with a refined assessment of the corresponding neural dynamics.