Cognitive flexibility is a core executive function vital for adaptation and adjustment to new information. The brain-derived neurotrophic factor (BDNF) single nucleotide polymorphism, val66met, has be Show more
Cognitive flexibility is a core executive function vital for adaptation and adjustment to new information. The brain-derived neurotrophic factor (BDNF) single nucleotide polymorphism, val66met, has been suggested to modulate cognitive flexibility but it remains unclear how confounding variables such as stress and sex influence this relationship. Environmental enrichment (EE) may protect against stress-induced effects. The aim of this study was to test whether BDNF val66met alters reversal learning, a key component of cognitive flexibility, when tested under stressful water maze conditions. We used a Sprague Dawley val66met rat model where pregnant val/met dams were moved to either low or high EE environments. Dams and offspring stayed in these environments until weaning, after which the offspring was moved to standard, moderate enrichment housing. Adult male and female val/val, val/met and met/met offspring then underwent a water maze reversal learning protocol. All groups rapidly learned the new location of the platform. Mediation analysis showed the relationship between val66met and cognitive flexibility was mediated by differential use of spatial strategies. Sequential clustering analysis demonstrated that val66met interacted with sex to predict cognitive flexibility performance with lower flexibility in met/met males and val/met females compared to other genotypes. EE was not a strong promotor of cognitive flexibility. Water maze testing increased corticosterone levels, confirming the stressful nature of the test. This study demonstrates the importance of considering stress and sex when investigating the role of BDNF val66met in cognitive flexibility. Show less
While mindfulness has demonstrated efficacy in enhancing executive function in non-athletes through improved present-moment awareness and acceptance of current experiences, particularly regarding atte Show more
While mindfulness has demonstrated efficacy in enhancing executive function in non-athletes through improved present-moment awareness and acceptance of current experiences, particularly regarding attention regulation and cognitive control, its neurocognitive mechanisms and the effects and underlying mechanisms of mindfulness-based intervention (MBI) on different executive functioning skills in athletic populations remain poorly understood. The purpose of this randomized controlled trial tackles a novel and important topic by investigating the beneficial effects of 12-week MBI on executive functioning skills in baseball players-a population that faces unique cognitive and physical demands, and the associated neurophysiological and biochemical regulation mechanisms. Thirty-four baseball players were randomly divided into the MBI group (11M/6F) and the control group (11M/6F). Executive functioning skills (N-back task for working memory, Stroop task for inhibitory control, and Switching task for cognitive flexibility) were tested before and after the intervention. Functional near-infrared spectroscopy (fNIRS) was used to record quantified hemodynamic responses in the prefrontal cortex through oxygenated hemoglobin concentration (Oxy-Hb) monitoring during the performance of executive function tasks. Biomarkers of cognitive function, including BDNF, IL-6, TNF-α, and Cortisol, were measured using enzyme-linked immunosorbent assays (ELISA). MBI partially improved all three executive function skills, with increased Oxy-Hb level in L-FPA during the task of working memory, increased Oxy-Hb level in R-VLPFC during the task of inhibitory control, and decreased Oxy-Hb level in R-FPA, M-FPA, and L-DLPFC during the task of cognitive flexibility. Furthermore, MBI increased circulating BDNF level and decreased IL-6 and Cortisol levels. In addition, our correlation analyses showed that improvement in executive function (improved behavioral performances and changes in Oxy-Hb levels) were associated with changes in Cortisol and inflammatory cytokines (TNF-α and IL-6). A 12-week MBI partially improved three components of executive function in baseball players. This enhancement may be attributed to the MBI-induced reductions in Cortisol and inflammatory cytokines (such as TNF-α and IL-6), which altered blood oxygen contents in specific brain regions, thereby promoting executive function. Show less