An important feature of human cognition is its remarkable flexibility. Cognitive control refers to processes that allow behaviour to vary adaptively depending on current goals. Understanding it is therefore fundamental to knowing how our behaviour can be adapted and flexible. Deficits in cognitive control, and imbalances in related neurotransmitters such as dopamine, are associated with a number of psychological and neurological conditions, including schizophrenia and the cognitive symptoms of Parkinson’s disease. Both prefrontal cortex (PFC) and anterior cingulate cortex (ACC) are known to have important roles in cognitive control, but the details of how they achieve this, how they interact, and the roles of those neurotransmitters are unclear. An important way to discover this is to record the effects of inactivating those regions and neurotransmitter systems, as this reveals how these systems are critical to cognition.This project will reveal the nature of the frontal lobe interactions that subserve cognitive control, and their neurochemical basis, by combining inactivation and neurophysiological techniques.In macaque monkeys performing a well-established test of multiple elements of cognitive control, we will reversibly inactivate targeted regions of ACC and PFC whilst simultaneously recording continuous neurophysiological data using chronically implanted electroencephalography. We will go on to record the same data during reversible localized blockade of targeted neurotransmitter systems, beginning with dopamine, and then to functionally disconnect ACC and PFC.The project will have significant benefits for both fundamental and clinical research, and represents a rare combination of techniques made possible by mobility between laboratories. It will substantially enhance the career of the researcher.