Role of Dopamine on Loss Aversion Behaviour: Study on Parkinsonian Patients

Overview

Use lay language. Many decisions involve the possibility of gaining or losing relative to the status quo. The loss aversion behaviour is a cognitive concept explaining that people are more sensitive to the possibility of losing objects or money than they are to the possibility of gaining the same objects or amounts of money. We hypothesised that dopamine could be involved in the loss aversion behaviour. To highlight this, we have chosen a model of dopaminergic depletion : the Parkinson's disease The primary purpose of this protocol is to study the role of dopamine in the loss aversion phenomenon by comparing brain activity in parkinsonian patient with and without treatment with L Dopa, when they are exposed to mixed (gain/loss) gambles using money. The second purpose is to highlight the role of a dopamine depletion by comparing patient without treatment vs healthy paired control. 2 groups : * 20 parkinsonian patients (tested two times : with and without treatment by L dopa) * 20 healthy paired control Description of the protocol for patients : J0 : Inclusion visit (duration : 4h): * motor assessment (UPDRS) * neuropsychological and psychiatric assessment (MMS, MATTIS, BREF, Stroop, Ardouin scale, UPPS, MADRS, Hamilton, LARS). J0+1 day and J0 +2 days : 2 visits of MRI (magnetic resonance imaging) acquisition (with or without treatment) : Each acquisition was composed by an orientation sequence+ an anatomic sequence + a functional sequence. For healthy subjects, they have only one visit of 2 hours including a MMS, a MADRS and the MRI acquisitions.

Use lay language. Many decisions involve the possibility of gaining or losing relative to the status quo. The loss aversion behaviour is a cognitive concept explaining that people are more sensitive to the possibility of losing objects or money than they are to the possibility of gaining the same objects or amounts of money. We hypothesised that dopamine could be involved in the loss aversion behaviour. To highlight this, we have chosen a model of dopaminergic depletion : the Parkinson's disease The primary purpose of this protocol is to study the role of dopamine in the loss aversion phenomenon by comparing brain activity in parkinsonian patient with and without treatment with L Dopa, when they are exposed to mixed (gain/loss) gambles using money. The second purpose is to highlight the role of a dopamine depletion by comparing patient without treatment vs healthy paired control. 2 groups : * 20 parkinsonian patients (tested two times : with and without treatment by L dopa) * 20 healthy paired control Description of the protocol for patients : J0 : Inclusion visit (duration : 4h): * motor assessment (UPDRS) * neuropsychological and psychiatric assessment (MMS, MATTIS, BREF, Stroop, Ardouin scale, UPPS, MADRS, Hamilton, LARS). J0+1 day and J0 +2 days : 2 visits of MRI (magnetic resonance imaging) acquisition (with or without treatment) : Each acquisition was composed by an orientation sequence+ an anatomic sequence + a functional sequence. For healthy subjects, they have only one visit of 2 hours including a MMS, a MADRS and the MRI acquisitions.