The effects of bathing on task-dependent activation in the prefrontal cortex
2021 Volume 42 Pages 105-112
Details
2021 Volume 42 Pages 105-112
Background
The prefrontal cortex is the most developed area of the human brain and is responsible for functions such as cognition and memory. Functional brain imaging has recently revealed task-dependent activation of the prefrontal cortex and has shown that this activity is reduced by mental illness and aging. In contrast, frequent bathtub bathing results in systemic improvement of blood flow. This suggests that bathtub bathing promotes task-dependent activation of the prefrontal cortex, but the relationship between bathing habits and brain activity is poorly understood.
Methods
To address this issue, bathing habits were varied in young adults and changes of total hemoglobin (HbT) in the prefrontal cortex were measured during tasks. HbT levels during three types of task: the Kana-Hiroi test, Wisconsin Card Sorting test (WCST) and N-back test, were compared with that during an eyes-open resting phase. Task-dependent changes of HbT were compared from before to after periods of shower and bathtub bathing, and correlations of task-dependent changes of HbT with grades of tasks were analyzed.
Results
Task-dependent changes of HbT occurred during attentional and memory tasks in young adults. There were dominant decreases in the left prefrontal cortex during the Kana-Hiroi test and WCST upon shower bathing for 2 weeks, and these changes were slightly reversed by bathtub bathing for the subsequent 2 weeks. Changes of HbT during the Kana-Hiroi test were positively correlated with the grade of the task.
Conclusion
These results indicate that bathing habits affect task-dependent activation of the prefrontal cortex.
