Using fMRI, Behrens, Rushworth and colleagues have used computational techniques to identify the regions of cerebral cortex that encode key parameters that are essential for decision-making and learning. This work will use MEG/EEG in combination with a variety of magnetic-resonance (MR) based methods and neurodisruptive stimulation methods to reveal the neural dynamics of human decision-making. The high temporal resolution of MEG/EEG will enable testing of quantitative models of the neuronal mechanisms underlying decision-making. Such models are specified at the level of neural networks and make predictions about regional brain activity on a millisecond-by-millisecond basis.