BASAL GANGLIA OUTPUTS THAT SUPPORT GOAL-DIRECTED BEHAVIOUR
Our recent work has shown that two different output nuclei of the basal ganglia play distinct roles in prediction. The first, the ventral pallidum (VP), contains separate classes of neurons that predict the appetitive or aversive value of stimuli and is critical for motivated behaviour (Stephenson-Jones et al., Neuron, 2020). The second, the habenula-projecting globus pallidus (GPh), is a key site where prediction errors are calculated and is essential for reinforcement learning (Stephenson-Jones et al., Nature, 2016). In one set of projects our aim is to create a comprehensive account of the computations that additional basal ganglia output nuclei perform. In this way we aspire to map the principle types of information that are being extracted by these nuclei to support purposive action.
CIRCUIT BASIS FOR ASSOCIATIVE LEARNING
Animals tend to repeat actions that lead to rewards (reinforcement learning), and also repeat actions that have been performed in the past. The striatum is a key area of the brain that mediates both forms of learning. One main focus of the lab is to identify the specific cell types, circuits and mechanisms that implement these two types of associative learning.
LEARNING MOTOR SEQUENCES
Systems that organise elemental neural representations into complex sequences are fundamental to the generation of meaningful behaviour. Just as individual phonetics make up words which are themselves organised into sentences, movements are constructed from discrete syllables of fine motor control. Animals learn to generate these movements when they are useful, and with repetition, these chained movements are honed into precise, stereotyped action sequences. One focus of the lab is to try and understand how the basal ganglia support the learning of such movements. How are these actions optimised with practise? And how do interactions with distributed cortical and subcortical circuits support motor sequence learning?
The lab uses a wide range of technical approaches