A CURVILINEAR RELATIONSHIP BETWEEN TESTOSTERONE AND SPATIAL COGNITIONIN HUMANS - POSSIBLE INFLUENCE OF HAND PREFERENCE

The nature of the relationship, if any, between performance on visuo-s patial 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-s patial 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 e vident in left-handers. Across the entire observed range of T, the rel ationship between spatial cognition and T was best described by an inv erted quadratic function in right-handers, but not in left-handers. A significant difference in spatial accuracy was seen among right-hander s tested in early vs. late morning testing sessions, in accordance wit h the expected diurnal change in circulating T. No significant relatio nships between salivary C and visuo-spatial performance were found. Th ese results are consistent with prior literature suggesting a curvilin ear relationship between spatial performance and circulating T concent rations, with intermediate levels of T being associated with better sp atial functioning, but raise the possibility that hand preference may be one factor that moderates the observed relationship. Copyright (C) 1996 Elsevier Science Ltd.