A Multimodal Investigation of Stress Effects on Memory Processes

The organism’s response to stress is an adaptive mechanism for keeping up the homeostasis in the moment of stress as well as for preparing the organism for similar situations reoccurring in the future. The stress response thus exerts influence on attentional and memory encoding processes from the onset of the stressful situation and in its aftermath, when consolidation processes come into play. This work investigated in three studies the effects of stress on fixation processes, on olfactory memory and on immediate memory for objects. An eye tracking study investigated whether stress, induced with the Trier Social Stress Test, influences fixation of central items, enhancing memory. The second study investigated effects of increased vigilance under stress via the auditory startle response, 24 hours later, in association with an odour experienced during the stressor. Memory enhancement and startle responsivity were further tested in direct aftermath of the stressor in a third study. The findings of the three studies contribute to the understanding of immediate and long-term physiological and behavioural stress effects.