My research program is geared to the development of a unified theory of brain operation that emphasizes the integrative capacity of the brain. One tenet of the theory is that cognitive operations emerge from the interactions between brain areas rather than being the sole responsibility of single regions. The program has two related arms: one to do with technical developments to explore brain integration, and the other with the collection of experimental evidence for this integration. This second arm uses modern brain imaging methods to explore the neural networks in human learning. One surprising outcome of this work has been the profound involvement of sensory processing regions of the brain in rather complex cognitive operations. This suggests that human cognition involves the active interaction among brain regions that processes specific sensory information (e.g., visual, auditory) and the mediating areas, such as prefrontal cortex and medial temporal lobes. In collaboration with Dr Cheryl Grady, we are undertaking a series of studies of the aged to explore whether age-related changes in cognition come about through physiological alterations in sensory systems, the mediating systems, or in the interaction between them.