Characterisation of post-stimulus responses to provide a novel measure of brain health

Post-stimulus responses are significant changes from baseline in measured brain function that occur after stimulus cessation. Post-stimulus responses are ubiquitous in human functional magnetic resonance imaging (fMRI) and electroencephalography/magnetoencephalography (EEG/MEG) studies. In fact until recently post-stimulus fMRI responses were thought to be entirely vascular in origin whilst the neurophysiological origin in EEG/MEG recording remains unclear. As a result they have been widely overlooked in neuroimaging due to uncertainty over whether these responses provide distinct, functionally relevant information additional to primary responses occurring during stimulation. However, recent evidence suggests that they can provide important markers of brain activity in health and disease. It is therefore imperative to improve characterisation of these responses and methods by which to study them across brain imaging modalities. This PhD will address accurate characterisation of post-stimulus responses across imaging modalities and use this characterisation to develop new methods to model these responses independently of responses occurring during stimulation. This characterisation and new analysis methods will open up a new window in which to study brain function which can be used across the neuroscience and neuro-clinical community in the future.