Magnetic resonance imaging correlates of set shifting.
The purpose of this study was to examine the relationships between lobar volumes and set shifting. We studied 101 subjects, including 36 normal controls, 16 patients with probable Alzheimer's disease, 30 patients with frontotemporal dementia (FTD), and 19 patients with semantic dementia (SD), using a shifting paradigm that carefully controlled for component abilities. Subjects were administered two conditions of the Delis-Kaplan Executive Function System (D-KEFS) Design Fluency Test. In the control condition (DF:Control), examinees generated as many unique designs as possible in 60 s by drawing lines connecting only unfilled dots. In the switching condition (DF:Switch), examinees generated designs by drawing lines alternating between filled and unfilled dots. We used BRAINS2 software to generate volumes of the right and left frontal, temporal, and parietal lobes. Partial correlations and multiple regressions showed that, after controlling for Mini-Mental State Examination and DF:Control, only the right and left frontal lobe volumes significantly correlated with the DF:Switch, most clearly in the FTD and SD groups. Follow-up analyses indicated that frontal contributions to shifting were not related to working memory. Results highlight the importance of carefully controlling for component cognitive processes when studying executive functioning.
Kramer
Joel H
JH
Department of Neurology, University of California San Francisco, San Francisco, CA 94143, USA. jkramer@memory.ucsf.edu
Quitania
Lovingly
L
Dean
David
D
Neuhaus
John
J
Rosen
Howard J
HJ
Halabi
Cathra
C
Weiner
Michael W
MW
Magnotta
Vincent A
VA
Delis
Dean C
DC
Miller
Bruce L
BL
D000368:Aged; D001931:Brain Mapping; D003704:Dementia / Q000145:classification / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D005625:Frontal Lobe / Q000473:pathology; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation / Q000379:methods; D011340:Problem Solving / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D012718:Set, Psychology