Send to

Choose Destination
Neuropsychologia. 2009 Oct;47(12):2564-73. doi: 10.1016/j.neuropsychologia.2009.05.003. Epub 2009 May 15.

The role of the basal ganglia and its cortical connections in sequence learning: evidence from implicit and explicit sequence learning in Parkinson's disease.

Author information

Sobell Department of Motor Neuroscience and Movement Disorders, UCL, Institute of Neurology, London, United Kingdom.


Implicit (unconscious/incidental) and explicit (conscious/intentional) learning are considered to have distinct neural substrates. It is proposed that implicit learning is mediated by the basal ganglia (BG), while explicit learning has been linked to the medial temporal lobes (MTL). To test such a dissociation we investigated implicit and explicit sequence learning in Parkinson's disease (PD), a disorder characterized by striatal dysfunction. We studied both implicit and explicit learning of a 12-item sequence of target locations in 13 PD patients and 15 age-matched controls. In the implicit sequence learning task all participants completed 10 blocks of a probabilistic serial reaction time (SRT) task in which they were exposed to the sequence without explicit knowledge of it. Participants also completed between 1 and 10 blocks of an explicit sequence learning task in which the sequence was learned deliberately by trial-and-error. Both implicit and explicit sequence learning were significantly impaired in PD patients compared to controls. The results indicate that, in addition to playing a role in implicit sequence learning, the BG and its frontal projections are also involved in explicit sequence learning.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center