We plan to study how the motivational control of behaviour is achieved by neuronal mechanisms operating in the basal ganglia.
This issue will be investigated by behavioural experiments, by neurophysiological recordings in behaving animals during specific learning situations, by imaging studies of humans performing learning tasks, and by neuropsychological investigations of human patients suffering from basal ganglia diseases.
Convergent lines of evidence suggest that the basal ganglia are importantly involved in the control of voluntary, goal-directed behaviour. However, it is largely unknown how neuronal mechanisms in these structures provide a physiological basis for the deficits occurring in human diseases and in experimentally lesioned animals. In particular, we would like to know how the motivational control of behaviour is achieved by neuronal mechanisms operating in the basal ganglia. This issue will be addressed at different levels of experimentation by asking the following questions: (i) How do motivational variables control learning in animals? The experiments will test the learning behaviour of rats under different degrees of motivation. (ii) With these behavioural variables in mind, how do individual basal ganglia structures participate in learning, and in which forms of learning? The experiments will be done with lesions of specific nuclei of the basal ganglia of rats and monkeys which learn and perform specific tasks involving basal ganglia mechanisms of reward processing and procedural motor and habit learning. (iii) Can we find single neurone correlates in the basal ganglia for specific motivational processes defined above, notably the processing of reward information and mechanisms underlying particular forms of learning? The experiments will involve the recording from single dopamine neurones in monkeys during basic forms of reward-directed (incentive) learning. (iv) As such experiments are commonly done on animals, do we find indications for comparable processes in the human basal ganglia? The experiments will investigate regional cerebral blood flow as an indicator of brain activity in human volunteers during specific learning tasks which are known from lesion studies to involve the basal ganglia. (v) Given our knowledge on normal basal ganglia functions in animal and human motivation, how are the behavioural processes and brain mechanisms altered in human patients suffering from a number of basal ganglia diseases that constitute an important portion of brain pathologies and a serious challenge for human health and welfare? Neuropsychological experiments will investigate the motivational and cognitive alterations in these patients.
Funding SchemeCSC - Cost-sharing contracts
CB2 3EB Cambridge