A team of researchers led by Bruno Delord, researcher at ISIR and professor of computational neuroscience at Sorbonne University, in collaboration with Philippe Faure, CNRS research director at the Ecole Supérieure de Chimie Physique Industrielle de la Ville de Paris (ESCPI), and Jérémie Naudé, CNRS research fellow at the Institut de Génétique Fonctionnelle (IGF) in Montpellier, has unveiled work exploring the role of dopamine in motivation. While this molecule is well known for its involvement in reinforcement learning, this research shows that it is also the driving force behind goal-directed actions, taking the analysis of brain mechanisms a step further.
Understanding dopamine beyond learning
For years, researchers have been interested in the role of dopamine in reinforcement learning, a mechanism by which the brain associates actions with rewards to adjust behaviour. This project goes a step further by exploring how dopamine, in addition to its role in learning, is at the origin of motivation, the driving force behind goal-directed actions.
The aim of this research is to decipher the biological mechanisms responsible for this key role of dopamine in motivation. Using a systems approach, the researchers are seeking to interpret the dynamics of cortical neuron networks, executive cognitive processes and observed animal behaviour, in order to gain a better understanding of the dopaminergic control that switches them into a goal-directed mode of functioning.
A dual role for dopamine
The results show that dopamine plays a vital dual role. During learning, it helps to create “latent attractors”: stable configurations of neuronal activity that correspond to past rewarded situations (for example, the action of drinking fresh water from the sink) and that can potentially attract neuronal activity towards these situations (the action of returning to the sink). However, only a motivational dopamine (triggering a need such as thirst) can activate these latent attractors and transform them into effective attractors that activate the behaviour (I want to drink, so I move) and direct it (I go to the sink).
This mechanism then leads to oriented behaviour: in our example, not only does the individual want to drink, but he also moves specifically towards the sink rather than at random. This discovery is the first mechanistic theory to explain, in a causal manner, how dopamine underpins motivation as both activational (acting) and directional (acting with a goal) behaviour.
Research at the interface between neuroscience and robotics
This work falls within the context of research at the interface between neuroscience and robotics at ISIR. More specifically, computational neuroscience activity within the ACIDE team, which aims to describe and understand executive processes in animals and humans, which is essential in these fields.
This study, entitled « Dopamine builds and reveals reward-associated latent behavioural attractors », has been published in the scientific journal Nature Communications. This is a major advance in our understanding of the brain and its mechanisms, which could transform the way we understand the relationship between motivation and behaviour.
Scientific advisor: Bruno Delord, Professor of Computational Neuroscience
Find out more about this research.
Published on 09/12/2024.
