Learning a course, playing sports, losing weight, going to work by bike instead of by car… Motivation is a key ingredient in everyday life. But what exactly is it? What are its neurobiological bases? What are its levers? And what research is being done on this topic at the Paris Brain Institute? Answers.
What is motivation?
Motivation is a crucial element of our societies that many teachers, business leaders, sports coaches and managers seek to develop. By definition, it is an energy that causes people to start, maintain or stop something that is difficult or unpleasant to do or stop. In so doing, it allows progress to be made toward a given goal, even in the face of troublesome internal or external factors: fatigue, time constraints, the desire to do something else, etc.
Motivation, etymologically “setting in motion”, can be defined as a function that activates and directs behaviour towards a goal.
According to decision theory, which attempts to rationally describe the modalities leading an individual to make a decision, the direction and intensity of behaviour are adjusted so as to maximize the expected benefit while minimizing the cost. In other words, the level of motivation for a given task (e.g. playing sport) corresponds to the difference between what this action will bring, the satisfaction of the objective achieved (better health, lower stress levels, etc., here) and what it will cost, the mental or physical hardships of the action (need to go to the place where the sport is practised, need to be physically active, etc.).
According to this theory, a rational choice is to select the stock with the highest net worth, which is the maximum difference between expected benefits and costs.
Brain Zones and Motivational Neurotransmitters
The reward network consists mainly of the medial orbitofrontal cortex (COFM), the ventral striatum (SV), and the dopaminergic nuclei of the mesencephalon (NDM). The network of effort consists mainly of the anterior Insula (IA) and the dorsal anterior cingulate cortex (CCAD).
Garce to functional MRI, it has been shown that the MFOC plays a primary role in assigning the value of the reward while the AI assigns the cost of effort (1). This information enables the calculation of the net value of the share, profits less costs, in the CCAD. The ventral part of the striatum (SV) activates in response to the expected reward and activates the cognitive and motor cortical regions to produce the requested effort.
Activation of the neural circuits of motivation results in the release of several brain molecules, or “neurotransmitters.” The main one is dopamine, the chemical messenger of pleasure. This molecule makes the person more sensitive to reward and amplifies the prospect of profit or the desire to perform the task in question.
Another important neurotransmitter is serotonin. She is involved in mood management. Often called the “happiness hormone,” it reduces the “costs” of an action: it will help to make it less restrictive and thus help to achieve it.
Another example is noradrenaline. A major neurotransmitter involved in stress and avoidance reactions, it influences the effort to be made: when faced with a difficult or unpleasant action, it helps to mobilize the physical and mental energy needed to accomplish the task.
Motivation Research at Paris Brain Institute
In neurological and psychiatric pathologies, motivation deficits such as apathy are common, in 40% of patients with parkinson’s disease or in 35% of cases after stroke and in the majority of depressives, for example. Current motivation studies assess motivation deficits using subjective questionnaires that provide no information on the underlying pathophysiological mechanisms.
At Paris Brain Institute, the “Motivation, Brain, and Behavior” team is proposing research based on computational models to identify cognitive causes, such as reduced sensitivity to reward, neuronal dysfunction such as impaired dopamine release, and finally a prediction of the effectiveness of psychostimulant therapy. The computational footprint could thus pave the way for more personalized medicine. The objective of the team is to:
better understand the brain mechanisms of motivation in normal and pathological conditions in order to open up new therapeutic avenues personalize to treat this symptom severely degrading the quality of life of patients and their autonomy.
References
- A. Lopez-Persem et al Nature Neurosci 23 (202) N°5, p.664-675
- Les comptes Rendus Biologies, institut de France, Académie des sciences, vol 344, issue 3 (2021) p 275-296.
https://comptes-rendus.academie-sciences.fr/biologies/item/10.5802/crbiol.61.pdf
Team https://institutducerveau-icm.org/en/team/equipe-pessiglione-daunizeau-bouret/#more-2628
