Format

Send to

Choose Destination
Parkinsonism Relat Disord. 2008 Aug;14(6):457-64. doi: 10.1016/j.parkreldis.2007.11.009. Epub 2008 Mar 3.

Implicit and explicit aspects of sequence learning in pre-symptomatic Huntington's disease.

Author information

1
Department of Physiology & Pharmacology, CUNY Medical School, New York, NY 10031, USA. lice.mg79@gmail.com

Abstract

Learning deficits may be part of the early symptoms of Huntington's disease (HD). Here we characterized implicit and explicit aspects of sequence learning in 11 pre-symptomatic HD gene carriers (pHD) and 11 normal controls. Subjects moved a cursor on a digitizing tablet and performed the following tasks: SEQ: learning to anticipate the appearance of a target sequence in two blocks; VSEQ: learning a sequence by attending to the display without moving for one block, and by moving to the sequence in a successive block (VSEQ test). Explicit learning was measured with declarative scores and number of anticipatory movements. Implicit learning was measured as a strategy change reflected in movement time. By the end of SEQ, pHD had a significantly lower number of correct anticipatory movements and lower declarative scores than controls, while in VSEQ and VSEQ test these indices improved. During all three tasks, movement time changed in controls, but not in pHD. These results suggest that both explicit and implicit aspects of sequence learning may be impaired before the onset of motor symptoms. However, when attentional demands decrease, explicit, but not implicit, learning may improve.

PMID:
18316233
PMCID:
PMC2562166
DOI:
10.1016/j.parkreldis.2007.11.009
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center