The relation of White Matter Hyperintensities to implicit learning in healthy older adults

OBJECTIVE: This study examined whether MRI evidence of cerebrovascular disease in the form of white matter hyperintensities (WMH) was associated with decreased implicit sequence learning performance in a high-functioning group of normal elderly volunteers. METHOD: One hundred and eight community-dwelling elderly individuals received an MRI and performed an implicit sequence learning task, the serial reaction time (SRT) task. RESULTS: Hyperintensities present in the white matter were associated with a decreased learning effect. This association was found with both deep white matter and periventricular changes. Other factors affecting SRT performance (i.e., baseline reaction time and switch-cost) were not significantly related to the presence of WMH. CONCLUSIONS: The results indicate that in addition to previously identified generalized cognitive deficits, WMH are also associated with a specific decrease in the implicit learning of sequences.