Interaction between attentional signals and dopamine error prediction: focus on midbrain dopaminergic projections to prefrontal cortex

Mid-brain dopamine is implicated in motivation and attentional processes related to error prediction. However, the dominant model of dopamine error prediction advanced over the past two decades is at odds with key behavioural observations and recent theories of attention that suggest top-down cortical control over error prediction. This leaves open the question about how the dopamine signal interacts with these top-down mechanisms.

I will exploit recent advances in optical approaches to brain function to explore this question using behavioural tasks in rats. I will use fibre photometry to record from dopaminergic projections to the medial prefrontal cortex during a discrimination task. I will determine whether there is increased activity for both positive and negative prediction error. I will also carry out a causal experiment using optogenetic inhibition of prefrontal vs. dopaminergic projections received by the nucleus accumbens in a blocking behavioural paradigm. This experiment will determine whether these projections differ in their contributions to error prediction.

This work will uncover novel mechanisms of dopamine reward prediction with implications for our understanding of the fundamental nature of attention and motivation.