Dopaminergic medication reduces striatal sensitivity to negative outcomes in Parkinson's disease.
Brain
; 142(11): 3605-3620, 2019 11 01.
Article
em En
| MEDLINE
| ID: mdl-31603493
ABSTRACT
Reduced levels of dopamine in Parkinson's disease contribute to changes in learning, resulting from the loss of midbrain neurons that transmit a dopaminergic teaching signal to the striatum. Dopamine medication used by patients with Parkinson's disease has previously been linked to behavioural changes during learning as well as to adjustments in value-based decision-making after learning. To date, however, little is known about the specific relationship between dopaminergic medication-driven differences during learning and subsequent changes in approach/avoidance tendencies in individual patients. Twenty-four Parkinson's disease patients ON and OFF dopaminergic medication and 24 healthy controls subjects underwent functional MRI while performing a probabilistic reinforcement learning experiment. During learning, dopaminergic medication reduced an overemphasis on negative outcomes. Medication reduced negative (but not positive) outcome learning rates, while concurrent striatal blood oxygen level-dependent responses showed reduced prediction error sensitivity. Medication-induced shifts in negative learning rates were predictive of changes in approach/avoidance choice patterns after learning, and these changes were accompanied by systematic striatal blood oxygen level-dependent response alterations. These findings elucidate the role of dopamine-driven learning differences in Parkinson's disease, and show how these changes during learning impact subsequent value-based decision-making.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Doença de Parkinson
/
Dopaminérgicos
/
Corpo Estriado
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article