Prefrontal cortex oxygenation and sleep quality in cognitive dual-task—fNIR study

Abstract

Abstract Background Previous studies suggest that poor sleep quality negatively affects the executive function of the prefrontal cortex and, consequently, the impairment of learning abilities. The aim of this study was to compare the oxygenated hemoglobin concentration ([HbO2]) during cognitive dual-task with subjective sleep quality in young adults. Methods Thirty-two healthy young adults (age = 23.13 ± 3.92 years, mean ± SD) were recruited according to the eligibility criteria. Using functional near-infrared spectroscopy (fNIR), oxygenated hemoglobin concentration ([HbO2]) was measured during quiet standing while performing a concurrent cognitive task - arithmetic and memory tasks (cognitive dual-task). The quality of sleep was assessed by the Pittsburgh Sleep Quality Index (PSQI). After data processing, the Mann-Whitney test was used for comparison and the statistical significance level was set to P < 0.05. Results There were 59.4% of participants with a global PSQI score ≤5 (good sleep quality) and 40.6% with a score > 5 (poor sleep quality). No differences were observed in the mean of [HbO2] in prefrontal cortex during cognitive dual-task in young adults with good and poor sleep quality (P > 0.05). Conclusions The results of this study do not support the possibility of increases in the hemodynamic response on the prefrontal cortex be expected due to a good sleep, once the sleep quality appears not to have a significant effect on [HbO2] in young adults during the performance of cognitive dual-task.