title: Age-related dedifferentiation of learning systems: an fMRI study of implicit and explicit learning.
abstract: 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.
authors.affiliation: Center for Cognitive Neuroscience, Duke University, Durham, NC, USA. nad12@psu.edu
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Dennis
authors.forename: Roberto
authors.initials: R
authors.lastname: Cabeza
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology* / Q000523:psychology; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D055815:Young Adult
references.citation: Brain. 1997 Jan;120 ( Pt 1):123-40
references.pmid: 9055803
references.citation: Proc Natl Acad Sci U S A. 1999 Oct 26;96(22):12881-6
references.pmid: 10536017
references.citation: Neurosci Biobehav Rev. 2002 Nov;26(7):795-808
references.pmid: 12470691
references.citation: Neuroimage. 2002 Jun;16(2):538-50
references.pmid: 12030836
references.citation: Behav Neurosci. 1993 Feb;107(1):3-22
references.pmid: 8447956
references.citation: Neuropsychologia. 2003;41(3):245-51
references.pmid: 12457750
references.citation: Psychol Aging. 1997 Mar;12(1):12-21
references.pmid: 9100264
references.citation: Science. 1998 Aug 21;281(5380):1185-7
references.pmid: 9712581
references.citation: Cold Spring Harb Symp Quant Biol. 1990;55:1007-23
references.pmid: 2132810
references.citation: Cereb Cortex. 2008 May;18(5):1201-9
references.pmid: 17925295
references.citation: J Neurosci. 2006 Jan 18;26(3):916-25
references.pmid: 16421311
references.citation: J Neurosci. 2000 Aug 15;20(16):6173-80
references.pmid: 10934267
references.citation: Eur J Neurosci. 1996 Apr;8(4):637-48
references.pmid: 9081615
references.citation: Psychol Aging. 1992 Jun;7(2):232-41
references.pmid: 1610513
references.citation: Neuropsychology. 2007 Nov;21(6):657-73
references.pmid: 17983277
references.citation: Neurosci Biobehav Rev. 2002 Nov;26(7):809-17
references.pmid: 12470692
references.citation: Neuroimage. 2002 Nov;17(3):1394-402
references.pmid: 12414279
references.citation: Neurobiol Aging. 2006 May;27(5):741-51
references.pmid: 15935517
references.citation: Behav Neurosci. 2004 Apr;118(2):438-42
references.pmid: 15113271
references.citation: Science. 1998 Apr 3;280(5360):77-81
references.pmid: 9525860
references.citation: Hippocampus. 1999;9(1):83-98
references.pmid: 10088903
references.citation: Neurobiol Aging. 2007 Nov;28(11):1749-58
references.pmid: 16919850
references.citation: Curr Opin Neurobiol. 2006 Dec;16(6):693-700
references.pmid: 17097284
references.citation: Proc Natl Acad Sci U S A. 2004 Aug 31;101(35):13091-5
references.pmid: 15322270
references.citation: Soc Cogn Affect Neurosci. 2009 Dec;4(4):423-8
references.pmid: 20035017
references.citation: Science. 1996 Sep 6;273(5280):1399-402
references.pmid: 8703077
references.citation: J Exp Psychol Learn Mem Cogn. 2008 Jul;34(4):791-808
references.pmid: 18605869
references.citation: Neuropsychologia. 2007 Nov 5;45(14):3157-66
references.pmid: 17716696
references.citation: J Neurosci. 2005 Feb 2;25(5):1203-10
references.pmid: 15689557
references.citation: Trends Cogn Sci. 2002 Feb 1;6(2):93-102
references.pmid: 15866193
references.citation: Neuroimage. 2002 Jan;15(1):273-89
references.pmid: 11771995
references.citation: Ann N Y Acad Sci. 1985;444:54-71
references.pmid: 3860122
references.citation: Curr Biol. 2000 Nov 2;10(21):R785-7
references.pmid: 11084350
references.citation: Hippocampus. 2003;13(5):572-86
references.pmid: 12921348
references.citation: Cereb Cortex. 2006 Dec;16(12):1771-82
references.pmid: 16421332
references.citation: Brain. 2003 Jan;126(Pt 1):43-56
references.pmid: 12477696
references.citation: Nature. 2001 Nov 29;414(6863):546-50
references.pmid: 11734855
references.citation: Q J Exp Psychol B. 1988 Aug;40(3):243-58
references.pmid: 3175038
references.citation: J Neurosci. 1989 Feb;9(2):582-7
references.pmid: 2521896
references.citation: Exp Brain Res. 2006 Oct;175(1):153-64
references.pmid: 16788812
references.citation: Brain. 2003 Jan;126(Pt 1):213-29
references.pmid: 12477708
references.citation: Brain. 2001 Jan;124(Pt 1):67-82
references.pmid: 11133788
references.citation: Cereb Cortex. 2009 Nov;19(11):2561-71
references.pmid: 19224975
references.citation: Psychol Aging. 2004 Mar;19(1):79-92
references.pmid: 15065933
references.citation: Behav Brain Res. 2001 Dec 14;127(1-2):199-207
references.pmid: 11718892
references.citation: J Neurosci. 1994 Mar;14(3 Pt 2):1450-62
references.pmid: 8126548
references.citation: Neurobiol Aging. 2003 Nov;24(7):1013-9
references.pmid: 12928061
references.citation: J Neurosci. 2005 Dec 7;25(49):11340-8
references.pmid: 16339029
references.citation: J Neurosci. 1989 May;9(5):1465-72
references.pmid: 2723738
references.citation: J Neuropsychiatry Clin Neurosci. 1997 Fall;9(4):568-73
references.pmid: 9447498
references.citation: Nat Neurosci. 1999 Sep;2(9):844-7
references.pmid: 10461225
references.citation: Psychol Aging. 2002 Mar;17(1):85-100
references.pmid: 11931290
references.citation: J Neurosci. 1994 Jun;14(6):3775-90
references.pmid: 8207487
references.citation: Psychon Bull Rev. 2001 Jun;8(2):343-50
references.pmid: 11495124
references.citation: Learn Mem. 2007 Aug 09;14(8):548-53
references.pmid: 17690338
references.citation: Learn Mem. 2007 Sep 24;14(10):645-54
references.pmid: 17893237
references.citation: Neuron. 2003 Mar 27;37(6):1013-25
references.pmid: 12670429
references.citation: Neuron. 2002 Dec 19;36(6):1221-31
references.pmid: 12495634
references.citation: Hum Brain Mapp. 1997;5(2):124-32
references.pmid: 10096417
references.citation: Nat Neurosci. 1999 Sep;2(9):775-6
references.pmid: 10461210
references.citation: J Cogn Neurosci. 2005 Jan;17(1):84-96
references.pmid: 15701241
references.citation: J Cogn Neurosci. 2000 Jan;12(1):174-87
references.pmid: 10769314
references.citation: Science. 1998 Aug 21;281(5380):1188-91
references.pmid: 9712582
references.citation: J Cogn Neurosci. 2008 Mar;20(3):432-46
references.pmid: 18004952
references.citation: J Cogn Neurosci. 1995 Fall;7(4):497-510
references.pmid: 23961907