The effects of acute stress on human prefrontal working memory systems.
Level 3 - non-randomized controlled study
Laboratory experimental study with controlled within-subject conditions; randomization is not explicitly stated in the abstract.
PubMed 18692209 · doi:10.1016/j.physbeh.2008.04.027
What was done
Participants completed a delayed-response item-recognition task with alternating blocks of high and low working memory (WM) demand across two experiments: a behavioral study (Experiment 1) assessing salivary cortisol and a functional magnetic resonance imaging study (Experiment 2). In the fMRI paradigm, subjects performed the task under three conditions: cold stress (cold-water hand immersion), a room-temperature water control (tepid-water hand immersion), and a no-water control.
What was found
Task performance was affected by working memory demand, but was not impaired by stress. Cold stress elicited higher salivary cortisol concentrations in behavioral subjects and greater prefrontal cortex signal change in fMRI subjects compared to both control conditions. The abstract provides no exact numerical values, effect sizes, or p-values.
Why it matters
The findings suggest that elevated prefrontal cortex activity under acute stress may serve a compensatory neural function necessary to preserve working memory processes and maintain behavioral organization.
Limits
Participant sample size, demographics, and randomization details are not reported in the abstract. The cold-water immersion protocol represents an acute physical stressor that may not generalize to psychological or chronic stress contexts, and quantitative data are absent.
Cited by
- contradicts During the first 20 to 30 seconds of deliberate cold exposure, prefrontal cortex activity and top-down impulse inhibition are greatly diminished.