Doctoral Thesis / Dissertation from the year 2013 in the subject Medicine – Neurology, Psychiatry, Addiction, grade: pass (in GB keine Benotung), University College London (Institute of Cognitive Neuroscience), course: Neurowissenschaften, language: English, abstract: Traditionally, the focus in cognitive neuroscience has been on so-called evoked neural activity in response to certain stimuli or experiences. However, most of the brain’s activity is actually spontaneous and therefore not ascribed to the processing of a certain task or stimulus – or in other words, uncoupled to overt stimuli or motor outputs. In this thesis I investigated the functional role of spontaneous activity with a focus on its role in contextual changes ranging from recent experiences of individuals to trial-by-trial variability in a certain task. I studied the nature of ongoing activity from two perspectives: One looking at changes in the ongoing activity due to learning, and the other one looking at the predictive role of prestimulus activity using different methodologies, i.e. EEG and f MRI. Finally, I ventured into the realm of inter-individual differences and mind-wandering to investigate the relationship between ongoing activity, certain behavioural traits and neuronal connectivity.