Pupil dynamics during very light exercise predict benefits to prefrontal cognition

軽運動の前頭前野機能向上効果は瞳に映る. 京都大学プレスリリース. 2023-07-12.Physical exercise, even stress-free very-light-intensity exercise such as yoga and very slow running, can have beneficial effects on executive function, possibly by potentiating prefrontal cortical activity. However, the exact mechanisms underlying this potentiation have not been identified. Evidence from studies using pupillometry demonstrates that pupil changes track the real-time dynamics of activity linked to arousal and attention, including neural circuits from the locus coeruleus to the cortex. This makes it possible to examine whether pupil-linked brain dynamics induced during very-light-intensity exercise mediate benefits to prefrontal executive function in healthy young adults. In this experiment, pupil diameter was measured during 10 min of very-light-intensity exercise (30% V̇o2peak). A Stroop task was used to assess executive function before and after exercise. Prefrontal cortical activation during the task was assessed using multichannel functional near-infrared spectroscopy (fNIRS). We observed that very-light-intensity exercise significantly elicited pupil dilation, reduction of Stroop interference, and task-related left dorsolateral prefrontal cortex activation compared with the resting-control condition. The magnitude of change in pupil dilation predicted the magnitude of improvement in Stroop performance. In addition, causal mediation analysis showed that pupil dilation during very-light-intensity exercise robustly determined subsequent enhancement of Stroop performance. This finding supports our hypothesis that the pupil-linked mechanisms, which may be tied to locus coeruleus activation, are a potential mechanism by which very light exercise enhances prefrontal cortex activation and executive function. It also suggests that pupillometry may be a useful tool to interpret the beneficial impact of exercise on boosting cognition

How Exercise Impacts the Brain and Cognition

Physical exercise has been shown to impact the brains composition and functionality. The changes that arise in the structure of brain, as result of engaging in physical exercise, give rise to cognitive changes. Structural changes are observed most notably in the prefrontal cortex and hippocampus. These changes are preceded by elevations in cerebral blood flow, and growth factors, resulting increased neuroplasticity and neurogenesis. Frequency, duration, intensity, and type of physical exercise can have differing effects on the brain. Moderate intensity aerobic exercise presents the most profound improvements in memory, and inhibitory control over time

Oculomotor Task-Switching Performance Improves and Persists Following a Single Bout of Aerobic Exercise

Executive function includes the core components of response inhibition, working memory, and cognitive flexibility. Interestingly, an accumulating evidence has reported that inhibitory control and working memory improve following a single bout of exercise. It is, however, largely unclear whether cognitive flexibility elicits a similar post-exercise benefit. Accordingly, Chapter Two of my thesis examined whether 20-min of aerobic exercise provides an immediate post-exercise ‘boost’ to cognitive flexibility. Chapter Three examined for how long a putative post-exercise benefit persists. Cognitive flexibility was examined via an AABB task-switching paradigm wherein participants alternated between a well-practiced and a novel oculomotor task pre- and post-exercise. Chapter Two showed an immediate post-exercise benefit to cognitive flexibility and Chapter Three demonstrated that the benefit persists for up to 47-min post exercise. As such, my thesis provides convergent evidence that a single bout of exercise benefits each core component of executive function

The Influence of an Acute Exercise Bout on Adolescents' Stress Reactivity, Interference Control, and Brain Oxygenation Under Stress

Background:High psychosocial stress can impair executive function in adolescents,whereas acute exercise has been reported to benefit this cognitive domain. The aim ofthis study was to investigate whether an acute bout of aerobic exercise improves theinhibitory aspect of executive function and the associated dorsolateral prefrontal cortex(DLPFC) oxygenation when under stress.Methods:Sixty male high school students aged 16–20 years performed a Strooptask (baseline condition) and were randomly assigned to an exercise group (30 min onergometer at 70% of maximum heart rate) and a control group (30 min of reading).Subsequently, all participants underwent a modified Trier Social Stress Test, whichincluded a Stroop task under enhanced stress. The Stroop tasks in both conditionswere combined with functional near-infrared spectroscopy to record changes in DLPFCoxygenation in response to the tasks. Stress reactivity was measured with salivasamples (cortisol, alpha-amylase), heart rate monitoring, and anxiety scores.Results:All stress parameters indicated increases in response to the stressor(p<0.001), with higher alpha-amylase [t(58) =−3.45,p= 0.001,d= 1.93] andanxiety [t(58) =−2.04,p= 0.046,d= 0.53] reactions in the control compared to theexercise group. Controlling for these two parameters, repeated measures analyses ofcovariance targeting changes in Stroop interference scores showed no main effect ofstress [F(1,58) = 3.80,p= 0.056,ηp2= 0.063] and no stress×group interaction[F(1,58) = 0.43,p= 0.517,ηp2= 0.008]. Similarly, there was no main effect ofstress [F(1,58) = 2.38,p= 0.128,ηp2= 0.040] and no stress×group interaction[F(1,58) = 2.80,p= 0.100,ηp2= 0.047] for DLPFC oxygenation.Conclusion:Our study confirms potentially health-enhancing effects of acute exerciseon some of the physiological and psychological stress reactivity indicators. However,our data do not support the notion of an effect on interference control and DLPFCactivation under stress

A review of acute aerobic exercise and transcranial direct current stimulation effects on cognitive functions and their potential synergies

Today, several pharmaceutic and non-pharmaceutic approaches exist to treat psychiatric and neurological diseases. Because of the lack of treatment procedures that are medication free and the lack of severe side effects, transcranial direct current stimulation (tDCS) and aerobic exercise (AE) have been tested to explore the potential for initiating and modulating neuroplasticity in the human brain. Both tDCS and AE could support cognition and behavior in the clinical and non-clinical context to improve the recovery process within neurological or psychiatric conditions or to increase performance. As these techniques still lack meaningful effects, although they provide multiple beneficial opportunities within disease and health applications, there is emerging interest to find improved tDCS and AE protocols. Since multimodal approaches could provoke synergetic effects, several recent studies have begun to combine tDCS and AE within different settings such as in cognitive training in health or for treatment purposes within clinical settings, all of which show superior effects compared to single technique applications. The beneficial outcomes of both techniques depend on several parameters and the understanding of neural mechanisms that are not yet fully understood. Recent studies have begun to directly combine tDCS and AE within one session, although their interactions on the behavioral, neurophysiological and neurochemical levels are entirely unclear. Therefore, this review a) provides an overview of acute behavioral, neurophysiological, and neurochemical effects that both techniques provoke within only one single application in isolation; b) gives an overview regarding the mechanistic pathways; and c) discusses potential interactions and synergies between tDCS and AE that might be provoked when directly combining both techniques. From this literature review focusing primarily on the cognitive domain in term of specific executive functions (inhibition, updating, and switching), it is concluded that a direct combination of tDCS and AE provides multiple beneficial opportunities for synergistic effects. A combination could be useful within non-clinical settings in health and for treating several psychiatric and neurologic conditions. However, there is a lack of research and there are several possibly interacting moderating parameters that must be considered and more importantly must be systematically investigated in the future

Effect of acute aerobic exercise on cognitive performance: Role of cardiovascular fitness

Objectives: To determine whether fitness and cognitive task type moderate the relationship between acute exercise and cognition. Methods: Thirty-six healthy college-aged adults completed a maximal graded exercise test and were categorized as low, moderate, or high in cardiovascular fitness. Participants then performed the Stroop Test prior to and after an acute bout of cycling exercise that consisted of a 5-min warm-up, 20 min of exercise at moderate intensity (65% VO2max), and a 5-min cool-down. Results: Individuals of all fitness levels improved in cognitive performance following exercise. With regards to fitness, while no differences were observed on the congruent condition as a function of fitness, high fit individuals showed the longest response time on the Stroop incongruent condition.ConclusionThe beneficial relationship between performance of an acute bout of exercise and cognitive performance were observed for both cognitive task types and for participants of all fitness levels. However, a curvilinear relationship was observed between fitness and cognitive task type performance such that participants who were moderately fit performed the best on the incongruent trials, implying that maintaining fitness at a moderate level is associated with better executive functio

Effects of acute exercise on executive function: a study with a Tower of London Task

The purpose of this study is to extend the literature by examining the effects of an acute bout of moderate to vigorous intensity aerobic exercise on the executive functions of planning and problem solving assessed using a Tower of London Task (TOL Task). Forty-two participants were randomly assigned into either exercise or control group, and performed the TOL Task, before and immediately following exercise or a control treatment. The exercise group performed 30 min of exercise on a stationary cycle at moderate to vigorous intensity while the control group read for the same length of time. Results indicated that the exercise group achieved improvements in TOL Task scores reflecting the quality of planning and problem solving, but not in those reflecting rule adherence and performance speed. These findings indicate that an acute bout of aerobic exercise has facilitative effects on the executive functions of planning and problem solving

An Acute Bout of Exercise Improves the Cognitive Performance of Older Adults.

There is evidence that an acute bout of exercise confers cognitive benefits, but it is largely 2 unknown what the optimal mode and duration of exercise is and how cognitive performance 3 changes over time after exercise. We compared the cognitive performance of 31 older adults 4 using the Stroop test before, immediately after, and at 30 and 60 minutes after a 10 and 30 5 minute aerobic or resistance exercise session. Heart rate and feelings of arousal were also 6 measured before, during and after exercise. We found that independent of mode or duration of 7 exercise, the participants improved in the Stroop Inhibition task immediately post-exercise. We 8 did not find the exercise influenced the performance of the Stroop Color or Stroop Word 9 Interference tasks. Our findings suggest that an acute bout of exercise can improve cognitive 10 performance, and in particular the more complex executive functioning, of older adults

The effect of acute high-intensity interval training and Tabata training on inhibitory control and cortical activation in young adults

IntroductionPhysical exercise not only benefits peoples’ health, but also improves their cognitive function. Although growing evidence suggests that high-intensity interval training (HIIT) is a time-efficient exercise regime that can improve inhibitory control performance by enhancing cortical activation in the prefrontal cortex, less is known about how Tabata training, a subset of HIIT that requires no equipment or facilities to perform, affects inhibitory control and cortical activation in young adults. Therefore, we aimed to reveal the effect of an acute bout of HIIT and Tabata training on inhibitory control and attempted to identify its potential neural substrates.MethodsForty-two young adults (mean age: 19.36 ± 1.36 years; 21 females) performed the Stroop task and Simon task before and after acute HIIT, Tabata training, or a control session, and cortical hemodynamic changes in the prefrontal area were monitored by functional near-infrared spectroscopy (fNIRS) during the tasks. Both HIIT and Tabata interventions lasted for a total of 12 min. The HIIT participants performed ergometer cycling at their 80% maximal aerobic power at 90–100 rpm, and the Tabata participants performed a total of 8 intense activities, such as jumping jacks, high knees, and butt kickers, without using equipment or facilities, keeping the heart rate at 80–95% of their maximum heart rate. Participants in the control group watched a sport video while sedentary. Cognitive tasks data and fNIRS data were analyzed by repeated-measures three-way ANOVA.Results and discussionOur results indicated that both the HIIT and Tabata groups exhibited reduced reaction times after the intervention, and there were alterations in activation patterns in the dorsolateral and ventrolateral prefrontal cortices