Final Report Summary - ACTSELECTCONTEXT (Action Selection under Contextual Uncertainty: the Role of Learning and Effective Connectivity in the Human Brain)
The research in this project was carried out with complementary and mutually reinforcing methodologies, including novel developments made throughout the project: computational modelling, brain imaging, neurostimulation, and pharmacological interventions. This demonstrated that our motor system is indeed continuously influenced by beliefs about what might happen in the world. These beliefs inform, at a neurophysiological level, action representations in premotor and motor cortex. Moreover, decision processes themselves depend on whether they occur in the context of a required action, or are liberated from such requirements. Several neurotransmitters, including Dopamine, Noradrenaline, and Acetylcholine, play important roles in computing uncertainty estimates, and how these inform the selection of our actions, thus providing important insight into the possible mechanism through which out brain controls such behaviours. These results were broadly confirmed both for uncertainty computations about what will happen (eg reward information) and when it will occur (ie temporal processing), suggesting that some fundamental principles exist in how our brain forms estimates about uncertainty, and then communicates these to the motor system so that appropriate actions can be selected. ActSelectContext also provided evidence that this communication occurs through multiple anatomical routes, which depend on the specific requirements in which uncertainty estimates have to be formed (eg uncertainty about reward or time). Perturbation of these systems through brain stimulation or pharmacological interventions provided some interventional evidence that without the ability to form uncertainty estimates, specific aspects of action selection and preparation are not possible. Finally, in order to push the boundaries of how we can assess and measure brain activity and thus the mechanisms through which our brain transforms beliefs into actions, we have worked on novel so-called high precision MEG approaches that now allow for recordings of brain activity in humans with much improved precision.
In summary, by using complementary approaches and novel methodologies, the project contributed to our understand about how our brain deals with uncertain information, forms decisions based on estimates of uncertainty, and how this information is used to inform movement related brain regions about the best movement to select.