title: Executive function mediates effects of white matter hyperintensities on episodic memory.
abstract: This study examined the relationship between white matter hyperintensities (WMH) and executive functioning on episodic memory in a group of older adults who were cognitively normal or diagnosed with MCI or dementia. Volumetric magnetic resonance imaging (MRI) measures of total brain volume, white matter hyperintensity volume, and hippocampal volume along with age, education, and gender were evaluated as predictors of episodic memory. WMH were found to influence both episodic memory and executive functioning independently of other variables. The influence WMH on episodic memory was mediated by executive functioning and was completely eliminated when the interaction between executive functioning and hippocampal volume was entered in the regression model. The results indicate that executive functioning mediates the effects of WMH on episodic memory but that executive functioning and hippocampal volume can also interact such that executive functioning can exacerbate or ameliorate the influence of hippocampal volume on episodic memory.
authors.affiliation: Psychology Department, University of Nevada, Las Vegas, NV 89154, United States. colleen.parks@unlv.edu
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Parks
authors.forename: Ana-Maria
authors.initials: AM
authors.lastname: Iosif
authors.forename: Sarah
authors.initials: S
authors.lastname: Farias
authors.forename: Bruce
authors.initials: B
authors.lastname: Reed
authors.forename: Dan
authors.initials: D
authors.lastname: Mungas
authors.forename: Charles
authors.initials: C
authors.lastname: DeCarli
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D060825:Cognitive Dysfunction / Q000473:pathology / Q000523:psychology*; D003704:Dementia / Q000473:pathology / Q000523:psychology*; D004522:Educational Status; D056344:Executive Function; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D061212:Memory, Episodic; D009483:Neuropsychological Tests; D009929:Organ Size; D012737:Sex Factors