Cognitive sequence learning in Parkinson's disease and amnestic mild cognitive impairment: Dissociation between sequential and non-sequential learning of associations.
Neuropsychologia
; 45(7): 1386-92, 2007 Apr 08.
Article
em En
| MEDLINE
| ID: mdl-17188311
ABSTRACT
Evidence suggests that dopaminergic mechanisms in the basal ganglia (BG) are important in the learning of sequential associations. To test the specificity of this hypothesis, we assessed never-medicated patients with Parkinson's disease (PD) and amnestic mild cognitive impairment (aMCI) using a chaining task. In the training phase of the chaining task, each link in a sequence of stimuli leading to reward is trained step-by-step using feedback after each decision, until the complete sequence is learned. In the probe phase of the chaining task, the context of stimulus-response associations must be used (the position of the associations in the sequence). Results revealed that patients with PD showed impaired learning during the training phase of the chaining task, but their performance was spared in the probe phase. In contrast, patients with aMCI with prominent medial temporal lobe (MTL) dysfunctions showed intact learning during the training phase of the chaining task, but their performance was impaired in the probe phase of the chaining task. These results indicate that when dopaminergic mechanisms in the BG are dysfunctional, series of stimulus-response associations are less efficiently acquired, but their sequential manner is maintained. In contrast, MTL dysfunctions may result in a non-sequential learning of associations, which may indicate a loss of contextual information.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doença de Parkinson
/
Aprendizagem Seriada
/
Transtornos Cognitivos
/
Amnésia
Tipo de estudo:
Risk_factors_studies
Limite:
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Neuropsychologia
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Hungria