title: A curvilinear relationship between testosterone and spatial cognition in humans: possible influence of hand preference.
abstract: The nature of the relationship, if any, between performance on visuo-spatial tests in humans and circulating testosterone (T) concentrations remains controversial. We investigated possible relationships between salivary T and cortisol (C) concentrations and performance on visuo-spatial and verbal cognitive tests in a sample of healthy young adults. Among right-handers, salivary T was found to be negatively correlated with spatial performance in males, but was positively correlated with a measure of spatial visualization in females. This pattern was not evident in left-handers. Across the entire observed range of T, the relationship between spatial cognition and T was best described by an inverted quadratic function in right-handers, but not in left-handers. A significant difference in spatial accuracy was seen among right-handers tested in early vs. late morning testing sessions, in accordance with the expected diurnal change in circulating T. No significant relationships between salivary C and visuo-spatial performance were found. These results are consistent with prior literature suggesting a curvilinear relationship between spatial performance and circulating T concentrations, with intermediate levels of T being associated with better spatial functioning, but raise the possibility that hand preference may be one factor that moderates the observed relationship.
authors.affiliation: Department of Psychology, University of Western Ontario, London, Canada. moffat@sscl.uwo.ca
authors.forename: S D
authors.initials: SD
authors.lastname: Moffat
authors.forename: E
authors.initials: E
authors.lastname: Hampson
mesh_terms: D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology; D011863:Radioimmunoassay; D012463:Saliva / Q000737:chemistry; D012727:Sex Characteristics; D013028:Space Perception / Q000502:physiology*; D013739:Testosterone / Q000097:blood*; D014936:Word Association Tests
chemical_list: D013739:Testosterone