INTRODUCTION: Aircrew in-flight bladder relief remains an understudied stressor; specifically the effects of withholding urination on flight-relevant cognitive performance. This quasi-experimental study investigated whether voluntary urinary retention over a 3-h period negatively impacted cognitive performance.METHODS: We assessed vigilance using the psychomotor vigilance task (PVT) and measured the P3b event-related potential (ERP) in response to PVT stimuli. We also measured working memory (WM) performance using a change detection task and assessed the contralateral delay activity during the WM task using electroencephalography (EEG). Subjects (N = 29) completed a baseline test on both tasks, following bladder voiding and immediately after consuming 0.75 L of water. Subjects performed tasks at 1, 2, and 3 h post-void and urgency to void one’s bladder was assessed regularly. A total of 17 subjects were able to complete the entire study protocol. Repeated-measures ANOVAs assessed changes in PVT and WM outcomes.RESULTS: Reaction time (RT) on the PVT was significantly impaired (5% slower) with longer urinary retention time and showed a 2.5-fold increase in the number of lapses (RT > 500 ms) with increased retention time. Together these results indicate that sustained attention was impaired with increased voluntary urine retention. We did not see significant changes in WM performance with our manipulations. Additionally, neural measures acquired with EEG for both tasks did not show any significant effect.DISCUSSION: As measured with the PVT, sustained attention was impaired during 3 h of voluntary urinary retention, highlighting the need for further development of adequate bladder relief systems in military aviation.Griswold CA, Vento KA, Blacker KJ. Voluntary urinary retention effects on cognitive performance. Aerosp Med Hum Perform. 2023; 94(2):79–85.