Functional magnetic resonance imaging (FMRI) is a designed experiment  which often consists of a patient being given a sequence of stimuli AB or ABC. Imaging takes place while the patient is responding either passively or actively to these stimuli. A model is used which views the observed time courses as being made up of a linear (polynomial) trend, responses (possibly zero valued) due to the presentation of the stimuli, and other cognitive activites that are typically termed random and grouped into the error term. The association between the observed time course in each voxel and the sequence of stimuli is determined. Diﬀerent levels of activation (association) for the stimuli are colored accordingly. This chapter focuses on block designs but is readily adapted to event-related designs.