Motivation is what drives us to act. Many diseases alter motivation.
A loss of motivation results in clinical apathy — a disabling disorder that can be difficult to pin down. It is often missed, and is hard to quantify. It carries a huge social and economic burden, and is often frustrating and distressing for carers.
Damage to some brain areas causes abnormal, misdirected motivation — sometimes leading to compulsive stereotyped behaviours, or unplanned impulsive acts. This can sometimes be dramatic, causing considerable embarassment for patients and their families.
We study what motivation is, in terms of computations. Is it the selection of an appropriate action, given a goal? Or is it the willingness to invest energy, at a cost, in a rewarding course of action? Here are a few of our studies.
- Increased and decreased responses to incentives after damage to specific brian areas: “Human ventromedial prefrontal lesions alter incentivisation by reward”, Manohar & Husain Cortex 2016
- Rewards and dopamine improve motor performance by reducing internal noise. “Reward pays the cost of motor and cognitive control”, Manohar et al. Current Biology 2015
- Motivation increases the strength of error-corrective internal feedback, making movements more robust to variability: “Motivation dynamically increases noise resistance by internal feedback during movement” Manohar et al., Neuropsychologia 2019