Acute stress does not modulate selective attention in a composite letter task.

Acute stress has been demonstrated to affect a diverse array of attentional processes, one of which is selective attention. Selective attention refers to the cognitive process of deliberately allocating attentional resources to a specific stimulus, while ignoring other, distracting stimuli. While catecholamines have been shown to narrow attention, investigations on the influence of the stress hormone cortisol have yielded ambiguous results. We conducted two separate studies utilizing different laboratory stress induction paradigms to examine if cortisol influences the ability to selectively attend to local or global elements of a visual stimulus. In Study 1, 72 healthy young men took part either in the stressful Socially Evaluated Cold Pressor Test (SECPT) or a non-stressful (warm water) control, before being exposed to a composite letter task (CLT). Study 2 comprised a sample of 72 healthy young men and women and made use of a modified version of the Trier Social Stress Test (TSST) as well as a non-stressful control version, the friendly-TSST (f-TSST). Via endocrine, physiological, and subjective markers, we confirmed a successful stress induction. As verified with Bayesian statistics, stress did not affect selective attention in neither of the two studies. Furthermore, we were able to replicate the previously demonstrated absence of global precedence for composite figures composed of letters. Our results offer novel insights into the temporal dynamics of the effects of acute stress on attentional processes. Future studies should manipulate the timing of stress induction and investigate the effects of stress on letter vs. non-letter composite figures to shed further light on the underlying mechanisms.

Enhanced memory for central visual and auditory elements experienced during a stressful episode.

Acute psychosocial stress has been shown to benefit memory for central visual elements of a stressful episode. Here, we aimed at investigating whether this effect is accompanied by improved visual memory for the committee members in a modified version of the Trier Social Stress Test (TSST). Specifically, we tested participants´ recognition memory for accessories located on the bodies of the committee members, as well as their faces. Moreover, we investigated how stress influences memories for the content of the verbal interactions. That is, we studied how well participants remembered factual information associated with the main stress source, like name, age, and position of the committee members, as well as how accurately they could recite the exact wording of phrases used by them. In a counterbalanced 2 × 2 design, 77 men and women took part either in a stressful or non-stressful version of the TSST. While stressed participants better remembered personal information about the committee members than non-stressed participants, no differences in memory for the correct wording of phrases could be observed. Furthermore, in line with our hypothesis, stressed participants better remembered central, but not peripheral visual stimuli, compared to non-stressed participants, while, contrary to our expectations, stress did neither affect memory for objects located on the bodies of the committee members nor their faces. Our results are in line with the theory of enhanced memory binding under stress and extend previous results regarding improved memory for central visual elements encoded under stress to auditory learning material associated with the stressor.

The influence of a glucose administration on stress responsivity and memory after a socially evaluated cold pressor test.

The nutritional state of participants prior to stress induction via a laboratory stressor has been demonstrated to influence reactivity of the Hypothalamus-Pituitary-Adrenal axis. So far, either primarily psychosocial or primarily physiological stressors have been utilized investigating this effect. In the present study, we aimed to fill this gap in the existing literature by utilizing a stressor that combines both elements, namely the Socially Evaluated Cold Pressor Test. Furthermore, we investigated how glucose consumption and subsequent stress induction influence long-term memory retrieval as well as working memory. In a 2 × 2 design, half of the 72 participants (36 women, 36 men) participated in the laboratory stressor while the other half participated in a control condition after having fasted for at least six hours. Thirty minutes prior to stress or control treatment, fasted participants consumed either 75 g of glucose or stevia-sweetened water. Salivary cortisol levels, systolic and diastolic blood pressure, as well as affect did not significantly differ between participants consuming glucose or the placebo beverage. Acute stress impaired working memory but had no effect on long-term memory retrieval. Glucose consumption did not significantly influence memory. Our results suggest that the intensity of a stressor might be important when determining the effects of a glucose administration on stress reactivity. The nutritional state of participants taking part in studies investigating the effects of acute stress on memory might be less decisive than previously assumed.