Different individuals can exhibit markedly different patterns of brain activity even when asked to perform the same task. This variability is often attributed to task strategy or compliance. I will show that individual differences in brain responses are, to a large degree, inherent to the brain, and can be predicted from task-independent measurements collected at rest. Using the HCP database, I will show that a simple model that trained to relate task-independent measurements to task activity can predict task activation maps for unseen subjects in several behavioural domains. I will also show an application to pre-surgical planning in patients.