Age-related dedifferentiation of learning systems: an fMRI study of implicit and explicit learning.

Journal Article (Journal Article)

Abundant research finds that in young adults explicit learning (EL) is more dependent on the medial temporal lobes (MTL) whereas implicit learning (IL) is more dependent on the striatum. Using fMRI, we investigated age differences in each task and whether this differentiation is preserved in older adults. Results indicated that, while young recruited the MTL for EL and striatum for IL, both activations were significantly reduced in older adults. Additionally, results indicated that older adults recruited the MTL for IL, and this activation was significantly greater in older compared with young adults. A significant Task × Age interaction was found in both regions-with young preferentially recruiting the MTL for EL and striatum for IL, and older adults showing no preferential recruit for either task. Finally, young adults demonstrated significant negative correlations between activity in the striatum and MTL during both the EL and IL tasks. These correlations were attenuated in older adults. Taken together results support dedifferentiation in aging across memory systems.

Full Text

Duke Authors

Cited Authors

  • Dennis, NA; Cabeza, R

Published Date

  • December 2011

Published In

Volume / Issue

  • 32 / 12

Start / End Page

  • 2318.e17 - 2318.e30

PubMed ID

  • 20471139

Pubmed Central ID

  • PMC2923680

Electronic International Standard Serial Number (EISSN)

  • 1558-1497

International Standard Serial Number (ISSN)

  • 0197-4580

Digital Object Identifier (DOI)

  • 10.1016/j.neurobiolaging.2010.04.004


  • eng