Cortical mechanisms of temporal perception

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Our senses constantly receive multiple bits of information from our surrounding environment. The capacity of our senses, however, is limited. For example, the temporal resolution is limited so that temporal differences between stimuli cannot be resolved if the differences are below a certain threshold. The limitation of the visual system can be seen for example in movies. Although a movie consists of a series of static frames, the temporal resolution of the visual system is not high enough to resolve the single frames.There is an ongoing debate about the neuronal processes that limit temporal perception. One theory debated for decades states that temporal perception is mediated by so-called perceptual cycles. In this theory, perceptual cycles are temporal integration windows, such that any information received within one perceptual cycle will be integrated to one single temporal percept. Perceptual cycles thus build a core unit of perception.Recent studies provided new evidence for this theory. These studies linked perceptual cycles to cycles of neuronal oscillations of a specific frequency. Consequently, neuronal oscillations might represent the neuronal basis of perceptual cycles. Although this theory seems intriguing, most evidence for the theory is only of correlative nature, while causal evidence is largely missing.In this project, I aim to investigate and establish a causal link between neuronal oscillations and temporal perception. Using magnetoencephalography (MEG), neuronal oscillations will be measured while the healthy participants perform a temporal discrimination task. By means of pharmacological intervention, neuronal oscillations will be modulated. Specifically, GBAergic interneurons, which are known to play a crucial role in the generation of neuronal oscillations, will be modulated by pharmacological intervention. Simultaneously, the impact of this modulation on temporal perception will be measured. By this directed modulation, the putative causal link between neuronal oscillations and temporal perception can be studied. Furthermore, in this project it might be possible to bridge a gap between neurochemical activity, neuronal oscillatory activity on a mesoscopic level as well as perception on the behavioural level.