NEODYNE · Decision making: from neurochemical mechanisms to network dynamics to behaviour

How we decide between different alternatives is a central question to cognitive neuroscience. Decisions may appear trivial (selecting between two meals), or sophisticated and long reaching (deciding whom to marry). Decisions constitute a highly dynamical process of evidence accumulation. These dynamics can be represented in cortical oscillations, which have attracted great interest as a key mechanism that coordinates fast computations. While a few studies have investigated the role of cortical oscillations in decision making, the underlying mechanisms translating neurochemical activity into network dynamics and ultimately into choice remain unknown. Although neuromodulator effects are well described at the cellular level, their network effects during high-level behaviours are not well understood. There is however evidence that neuromodulators also control cortical oscillations and that this may have behavioural relevance. For a mechanistic understanding of human decision making, it is essential to (1) study its fast temporal cortical dynamics and (2) understand how neurochemical signalling gives rise to network dynamics and ultimately to cognition. Biophysical network models are excellent tools for linking these different levels of investigation. Such an understanding is critically important not only from a basic science perspective, it will also further our understanding of psychiatric diseases, which are often characterized by anomalies in neurochemical systems, neural oscillations and decision making.The novel approach that is core to this proposal is to investigate whether and how neurochemical systems guide decision behaviour by modulating cortical dynamics. To achieve this ambitious goal, I will use a combination of imaging methods with computational modelling, pharmacological challenges and electrical brain stimulation. This new approach will allow me to move towards a mechanistic understanding of the systems-level dynamics underlying decision making.