title: Virtual navigation in humans: the impact of age, sex, and hormones on place learning.
abstract: Certain cognitive processes, including spatial ability, decline with normal aging. Spatial ability is also a cognitive domain with robust sex differences typically favoring males. However, tests of spatial ability do not seem to measure a homogeneous class of processes. For many, mentally matching rotated three-dimensional images is the gold standard for measuring spatial cognition in humans, while the Morris water task (MWT) is a preferred method in the domain of nonhuman animal research. The MWT is sensitive to hippocampal damage, a structure critical for normal learning and memory and often implicated in age-related cognitive decline. A computerized (virtual) version of the MWT (VMWT) appears to require and engage human hippocampal circuitry, and has proven useful in studying sex differences and testing spatial learning theories. In Experiment 1, we tested participants (20-90 years of age) in the VMWT and compared their performance to that on the Vandenberg Mental Rotation Test. We report an age-related deficit in performance on both tasks. In Experiment 2, we tested young (age 20-39) and elderly (age >60) participants in the VMWT and correlated their performance to the circulating levels of testosterone and cortisol. Our findings indicate that the persistence of male spatial advantage may be related to circulating testosterone, but not cortisol levels, and independent of generalized age-related cognitive decline.
authors.affiliation: Department of Psychology and Neuroscience, Canadian Centre for Behavioural Neuroscience, The University of Lethbridge, 4401 University Drive Lethbridge, Alberta, Canada T1H 6P4. ira.driscoll@uleth.ca
authors.forename: Ira
authors.initials: I
authors.lastname: Driscoll
authors.forename: Derek A
authors.initials: DA
authors.lastname: Hamilton
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Yeo
authors.forename: William M
authors.initials: WM
authors.lastname: Brooks
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Sutherland
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008875:Middle Aged; D012727:Sex Characteristics; D013028:Space Perception / Q000502:physiology*; D013739:Testosterone / Q000097:blood*; D014584:User-Computer Interface
chemical_list: D013739:Testosterone; D006854:Hydrocortisone