The effect of anticipatory psychosocial stress on frontal executive functions

Previous research has found that stress hormone cortisol affects cognition, especially those cognitive abilities associated with the areas of the brain abundant in glucocorticoid receptors (e.g. Lupien & McEwen, 1997). Most studies have shown negative effects of induced stress on the functions associated with the hippocampus. Less research has investigated the effects of stress on executive functions, associated with the frontal lobes, also rich in glucocorticoid receptors. The evidence of the effects of stress on frontal functions has been mixed. The present study investigated the effects of induced psychosocial stress on tests of executive functions, both traditional (Verbal Fluency and Cognitive Estimates) and ecologically valid (Zoo Map), in younger adults. 40 healthy female students were exposed to psychosocial stress by having them anticipate a public speech; and a non-stressed condition prior to the performance on the tests of executive functions. Skin conductance and heart rate were measured throughout the experiment to record changes in physiological responses to stress and questionnaires were used to assess participants’ perception of stress. Results showed that participants in the stress condition experienced significantly more negative emotions than participants in the control condition, as measured by questionnaires. Significant differences between performance on traditional and ecologically valid executive tasks were not found, however participants in the stress condition performed not significantly better at the Zoo Map task. The results demonstrated that executive functions might not be affected when participants are exposed to stress prior to the tasks of executive functions. Nonetheless, they may be affected by stress in a Yerkes-Dodson Law pattern