Does acute physiological stress impair the mental control that lets you ignore irrelevant information?
Psychology Research, UBC (PSYC 217) · November 2025 · Controlled Experiment, Poster Presentation
Challenge
Most stress research leans on social or cognitive stressors. This experiment tested whether a purely physiological stressor — brief, rapid breathing — also impairs inhibitory control, measured through Stroop interference.
Method
30
participants (n = 30)
A/B
between-subjects conditions
20s
paced-breathing manipulation
2
tailed t-test
Condition A completed 20 seconds of rapid, paced breathing; Condition B breathed normally. Both then ran a Stroop task, with practice trials included to reduce task-familiarity confounds.
Findings
114.76 vs 63.08 ms
mean Stroop interference (stress vs. control)
t(28) = 2.06
two-tailed test statistic
p = .049
statistically significant
The stress group showed roughly 82% more interference on average, and nearly double the variability. Stress didn’t just slow people down, it made performance less predictable.
Takeaway
Acute physiological stress measurably narrowed inhibitory control. The honest limits: a small, homogeneous sample and no manipulation check or heart-rate validation—a deliberate scope tradeoff for a one-term study. The natural next step inverts the question of whether controlled slow breathing (box breathing, 4-7-8) improves inhibitory control rather than impairing it.