Selective effects of physical exercise on choice reaction processes

The brain in motion-cognitive effects of simultaneous motor activity

During the last 30 years, a large number of behavioral studies have investigated the effect of simultaneous exercise on cognitive functions. The heterogeneity of the results has been attributed to different parameters, such as intensity or modality of physical activity, and the investigated cognitive processes. More recent methodological improvements have enabled to record electroencephalography (EEG) during physical exercise. EEG studies combining cognitive tasks with exercise have described predominantly detrimental effects on cognitive processes and EEG parameters. However, differences in the underlying rationale and the design of EEG versus behavioral studies make direct comparisons between both types of studies difficult. In this narrative review of dual-task experiments we evaluated behavioral and EEG studies and discuss possible explanations for the heterogeneity of results and for the discrepancy between behavioral and EEG studies. Furthermore, we provide a proposal for future EEG studies on simultaneous motion to be a useful complement to behavioral studies. A crucial factor might be to find for each cognitive function the motor activity that matches this function in terms of attentional focus. This hypothesis should be investigated systematically in future studies.

Effects of Moderate-to-Vigorous Acute Exercise on Conscious Perception and Visual Awareness

Background: the effect of acute exercise on cognition covers almost all stages of information processing, but few studies have focused on visual awareness. Reports on the appearance of faint speed-changes in the perception of stimuli were used as an index for visual awareness. Visual awareness was assessed after exercise or rest. Aside from the detection of speed-changes, speed-change discrimination was added as an index of perception. Results: the results showed that reports on the appearance of faint speed-changes were affected by acute aerobic exercise. The d' index was higher after exercise. The hit rate for speed-change detection was marginally significantly higher after exercise than after the sedentary test condition. Analysis of the results obtained for the discrimination task showed that discrimination speed was boosted only when subjects were aware of the speed-change. Importantly, neither false alarm rate nor response bias was affected by exercise. Conclusions: acute moderate- to vigorous-intensity aerobic exercise improved subjects' awareness of speed changes. In addition, there was a perceptual advantage due to exercise.

The effect of time of day and high intensity exercise on cognitive performances of elite adolescent karate athletes

To explore the effect of time of day (TOD) on several components of cognitive performance prior and post to a physically exhaustive task in a sample of adolescent elite athletes. In a counterbalanced and randomized order, fourteen highly trained male karate athletes (17 ± 0.96 years; 1.75 ± 0.07 m; 68.0 ± 9.50 kg; BMI 22.15 ± 0.54 kg.m^-2) completed two test sessions at 09h00 and 16h00. Cognitive performance was evaluated before and after the karate specific test (KST). During each session, participants completed the profile of mood state (POMS), simple (SRT) and choice (CRT) reaction times, comparison test (COMT), mental rotation test (MRT), egocentric distance estimation (DE), and the rating of perceived exertion (RPE). KST was not TOD dependent (p > .05, d = 0.33). RPE scores were higher in the afternoon compared to the morning (p < .05, d = 0.68). Before the KST, SRT (p < .01, d = 0.69), CRT (p < .01, d = 0.47), COMT (p < .01, d = 0.62) and MRT (p < .001, d = 0.65) were better in the afternoon than in the morning. However, DE was not affected by the TOD (P > .05). KST improved SRT (p < .01, d = 0.078), CRT (p < .001, d = 0.72), COMT (p < .001, d = 1.31) and MRT (p < .001, d = 0.80) performances only in the morning. Cognitive performances are TOD dependent with higher performances realized in the afternoon. Performing a high intensity exercise in the morning, but not in the afternoon, enhanced several aspects of cognitive performances. The current results indicate that an intensive warm-up could be beneficial when a morning competition requires high cognitive readiness.

A Review of Cognitive Changes During Acute Aerobic Exercise

A growing body of work has investigated the effects of acute, or single bouts of, aerobic exercise on cognitive function. However, review of this research has largely focused on changes following exercise, with less focus on cognitive changes during exercise. The purpose of this review is to discuss the critical characteristics of this literature to date, including: (1) what has been done, (2) what has been found, and (3) what is next. Furthermore, previous meta-analytic reviews have demonstrated there is a small positive effect on cognition when measured during exercise, with executive functions showing the largest effects. However, these reviews group executive functions together. Here we explore how inhibition, working memory and cognitive flexibility are individually impacted by factors such as exercise intensity or duration. Searches of electronic databases and reference lists from relevant studies resulted in 73 studies meeting inclusion criteria. Studies were grouped by executive and non-executive cognitive domains, intensity and duration of exercise bouts. Within the executive domain, we found that effects on working memory and cognitive flexibility remain mixed, effects on inhibition are clearer. Moderate intensity exercise improves response time, vigorous intensity impairs accuracy. Moderate to vigorous intensity improves response time across non-executive domains of attention, motor speed and information processing, with no significant effects on accuracy. Memory processes are consistently improved during exercise. Effects of exercise duration on response time and accuracy are nuanced and vary by cognitive domain. Studies typically explore durations of 45 min or less, extended exercise durations remain largely unexplored. We highlight factors to consider when assessing exercise-cognition relationships, as well as current gaps and future directions for work in this field.

Does type of active workstation matter? A randomized comparison of cognitive and typing performance between rest, cycling, and treadmill active workstations

Active workstations are associated with improved health outcomes, but differences in cognitive and typing outcomes between the types of active workstations are unclear. We addressed two main questions: (1) Are there differences in cognitive and typing performance between seated and active workstations? (2) Are there differences in cognitive and typing performance between cycling and treadmill workstations, specifically? Participants included 137 healthy young adults (74 female, mean age = 20.8 years) who completed two sessions. At session one (baseline), all participants completed cognitive and typing tests including the Rey-Auditory Verbal Learning Test, Paced Auditory Serial Addition Test, a typing test, and a flanker task while sitting at rest. At session two, participants were randomized to an active workstation group (treadmill or cycling desk) during which they performed the tests listed above in a randomized fashion, using alternate versions when available. Participants showed significantly better attention and cognitive control scores during the active session as compared to the seated session, but worse verbal memory scores during the active session. Participants were faster and more accurate at typing during the active session relative to the seated session. There were no significant differences between cycling or treadmill workstations on any cognitive or typing outcomes. Improvements during active sessions may be influenced by practice effects, although alternate forms were used when possible. We conclude that active workstations do not seem to largely impact cognitive abilities, with the exception of a slight decrease in verbal memory performance. Findings suggest active workstations, whether walking or cycling, are useful to improve physical activity, particularly when completing tasks that do not require verbal memory recall.

Constitutive and Stress-Induced Psychomotor Cortical Responses to Compound K Supplementation

Isolated ginsenoside metabolites such as Compound K (CK) are of increasing interest to consumer and clinical populations as safe and non-pharmacological means to enhance psychomotor performance constitutively and in response to physical or cognitive stress. Nevertheless, the influence of CK on behavioral performance and EEG measures of cortical activity in humans is undetermined. In this double-blinded, placebo-controlled, counterbalanced within-group study, dose-dependent responses to CK (placebo, 160 and 960 mg) were assessed after 2 weeks of supplementation in nineteen healthy men and women (age: 39.9 ± 7.9 year, height 170.2 ± 8.6 cm, weight 79.7 ± 11.9 kg). Performance on upper- and lower-body choice reaction tests (CRTs) was tested before and after intense lower-body anaerobic exercise. Treatment- and stress-related changes in brain activity were measured with high-density EEG based on event-related potentials, oscillations, and source activity. Upper- (−12.3 ± 3.5 ms, p = 0.002) and lower-body (−12.3 ± 4.9 ms, p = 0.021) response times improved after exercise, with no difference between treatments (upper: p = 0.354; lower: p = 0.926). Analysis of cortical activity in sensor and source space revealed global increases in cortical arousal after exercise. CK increased activity in cortical regions responsible for sustained attention and mitigated exercise-induced increases in arousal. Responses to exercise varied depending on task, but CK appeared to reduce sensory interference from lower-body exercise during an upper-body CRT and improve the general maintenance of task-relevant sensory processes.

Effect of Angle of View and Partial Sleep Deprivation on Distance Perception

The present study aimed to investigate the effects of intensive effort on egocentric distance perception according to different angles of view after sleep deprivation at the beginning (SDB) or at the end (SDE) of the night and after a normal sleep night (NNS). Ten male students soccer players (age 22.8 ± 1.3 years; body mass 72.0 ± 10.4 kg; body height 180.0 ± 3.0 cm) performed a repeated cycling (RS) exercise (10 × 6 s maximal cycling with 24 s in between) after SDB, SDE, and NNS. They were asked to estimate three distances (i.e. 15, 25, and 35 m) before and after RS from different angles of view [i.e. in front (0°) and in side (45° left and 45° right)]. For 35 m, distance estimation was better during NNS compared to SDB and SDE for the front and the two side angles either before or after RS (p < 0.05). Concerning 25 m, distance estimation was better after compared to before RS for the front angle during the NNS session (p < 0.05). For 15 m, distance estimation was better during NNS than SDB and SDE for the front and both side angles after RS (p < 0.05). We concluded that partial sleep deprivation negatively affected the estimation of the egocentric distance for the three angles of view either at rest or after RS exercise.

Effects of Mongolian Warm Acupuncture on iNOS/NO and Inflammatory Cytokines in the Hippocampus of Chronic Fatigue Rats

The inducible nitric oxide synthase/nitric oxide (iNOS/NO) signaling pathway and inflammatory cytokines play important roles in the pathogenesis of exercise-induced fatigue. Studies have found that Mongolian warm acupuncture (WA) could alleviate exercise-induced fatigue. However, the exact mechanisms underlying its effects remain unclear. In the present study, we investigated the effects of Mongolian WA on iNOS/NO signaling pathway and proinflammatory cytokines in a chronic exhaustive swimming-induced fatigue rat model. Animals were randomly divided into Control group, Ctrl + WA group, Model group, and Model + WA group. The body weight, exhaustive swimming time test, and Morris water maze test were performed before and after the chronic exhaustive swimming. The serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and iNOS were detected by enzyme linked immunosorbent assay (ELISA). The mRNA expressions of IL-1β, IL-6, TNF-α, IFN-γ, and iNOS in the hippocampus were measured by real-time polymerase chain reaction (RT-PCR). Moreover, the protein expression of iNOS in the hippocampus was measured by western blot, and the NO productions in the serum and hippocampus were detected by Griess reaction system. Chronic exhaustive exercise significantly reduced the body weight and exhaustive swimming time, and induced impairment in learning and memory, and which were reversed by WA treatment. Chronic exhaustive exercise also increased the expressions of iNOS and proinflammatory cytokines, while WA treatment significantly decreased the level of iNOS and proinflammatory cytokines. However, chronic exhaustive exercise did not affect the NO production. These findings demonstrated that WA could alleviate the chronic exhaustive swimming-induced fatigue and improve the learning and memory ability, and the actions might be related to the reduction of inflammatory response and iNOS expression.

Short-Term Effect of Physical Exercise at Lactate Threshold on Choice Reaction Time

The duration of the enhancement of choice reaction task efficiency by physical exercise at lactate threshold was studied. After healthy male students completed the exercise or nonexercise (control) period for 10 min., they performed a three-choice reaction task for 20 min. The mean heart rate during the choice reaction task after the exercise was higher than that after the control period ( p<.05). For average percentage of correct answers, there were no significant differences between the exercise and control conditions. The reaction time during the first 8 min. of the 20-min. choice reaction task after the exercise period was less than that after the control period and increased gradually thereafter. In conclusion, whereas the choice reaction time was improved by physical exercise at around lactate threshold, the positive effects were seen mainly in the early stages of the task.

Incremental Exercise, Plasma Concentrations of Catecholamines, Reaction Time, and Motor Time during Performance of a Noncompatible Choice Response Time Task

The primary purpose was to examine the effect of incremental exercise on a noncompatible response time task. Participants ( N = 9) undertook a 4-choice noncompatible response time task under 3 conditions, following rest and during exercise at 70% and 100% of their maximum power output. Reaction and movement times were the dependent variables. Maximum power output had been previously established on an incremental test to exhaustion. A repeated-measures multivariate analysis of variance yielded a significant effect of exercise intensity on the task, but observation of the separate univariate repeated-measures analyses of variance showed that only movement time was significantly affected. Post hoc Tukey tests indicated movement time during maximal intensity exercise was significantly faster than in the other two conditions. The secondary purpose of the study was to assess whether increases in plasma concentrations of adrenaline and nor-adrenaline during exercise and power output would act as predictor variables of reaction and movement times during exercise. Catecholamine concentrations were based on venous blood samples taken during the maximum power output test. None of the variables were significant predictors of reaction time. Only power output was a significant predictor of movement time ( R2 = .24). There was little support for the notion that peripheral concentrations of catecholamines directly induce a central nervous system response.

The effects of physical exertion on decision-making performance of Australian football umpires

Decision-making is a key component of an umpire's in-game performance, with each decision potentially having a direct impact on the result of the game. Additionally, umpires have to be physically fit to ensure they keep up with the gameplay. While research has identified the decision-making demands and running demands of umpires separately, few have explored the relationship between them. The aim of this investigation was to examine the relationship between physical exertion and decision-making performance of Australian football umpires at the sub-elite and junior levels. A total of 18 Australian football umpires (sub-elite, n = 10; junior n = 8) performed 10 × 300 m runs, with each repetition immediately followed by a video-based decision-making test, then 1 min of recovery. A Mann-Whitney U assessment indicated a significant difference between the sub-elite and junior level umpires for decision-making accuracy (U = 13.00, z = -2.43, P = 0.016, r = -0.5). However, there was no significant difference in response time (U = 28.00, z = -1.07, P = 0.315, r = -0.25). The sub-elite umpires completed the running efforts in significantly less time than the junior umpires (P < 0.05). Further, there was no significant correlation between decision-making performance and running times for either skill level (P > 0.05). This suggests decision-making performance may not be affected by physical exertion. Therefore, it may be suggested coaches of football umpires allocate more time to the decision-making development of their umpires instead of focusing largely on the physical fitness side, as is currently the trend.

The Influence of Exercise on Cognitive Performance in Normobaric Hypoxia

Although previous reports indicate that exercise improves cognitive function in normoxia, the influence of exercise on cognitive function in hypoxia is unknown. The purpose of this study was to determine if the impaired cognitive function in hypoxia can be restored by low to moderate intensity exercise. Sixteen young healthy men completed the ANAM versions of the Go/No-Go task (GNT) and Running Memory Continuous Performance Task (RMCPT) in normoxia to serve as baseline (B-Norm) (21% O2). Following 60 minutes of exposure to normobaric hypoxia (B-Hypo) (12.5% O2), these tests were repeated at rest and during cycling exercise at 40% and 60% of adjusted Vo2max. At B-Hypo, the % correct (p≤0.001) and throughput score (p≤0.001) in RMCPT were significantly impaired compared to B-Norm. During exercise at 40% (p=0.023) and 60% (p=0.006) of adjusted Vo2max, the throughput score in RMCPT improved compared to B-Hypo, and there was no significant difference in throughput score between the two exercise intensities. Mean reaction time also improved at both exercise intensities compared to B-Hypo (p≤0.028). Both peripheral oxygen saturation (Spo2) and regional cerebral oxygen saturation (rSo2) significantly decreased during B-Hypo (p≤0.001) and further decreased at 40% (p≤0.05) and 60% (p≤0.039) exercise. There was no significant difference in Spo2 or rSo2 between two exercise intensities. These data indicate that low to moderate exercise (i.e., 40%-60% adjusted Vo2max) may attenuate the risk of impaired cognitive function that occurs in hypoxic conditions.

Influence of Affective Changes on Behavioral and Cognitive Performances After Acute Bout of Exhaustive Exercise

The present study was conducted to evaluate the influence of acute, exhaustive, exercise on affective responses (affective valence and activation) and behavioral and cognitive performances in medical students using circumplex model, reaction time (RT), and P300, respectively. Twelve healthy, untrained, male medical students participated in self-controlled, counterbalanced trial conducted over two sessions: baseline and exercise. In the baseline session, recordings of auditory reaction time (ART), visual RT (VRT), and P300 latency and amplitude (using acoustic “oddball” paradigm) were taken at the end of 15 min seated rest. Exercise session comprised of continuous maximal graded incremental exercise until volitional exhaustion, on a computer-based motorized treadmill and recordings done after heart rate returned to within +10% of pre-exercise values. Perceived exertion, affective valence, and activation were assessed pre-exercise, during (30 s before the end of each stage), and post-exercise (immediately, 5 and 10 min after) by Borg’s scale, feeling scale (FS), and felt-arousal scale (FAS), respectively. There was marked variability in individual affective responses to a single bout of exhaustive exercise with few subjects showing activated pleasure (Energetic Arousal) and others showing activated displeasure (Tense arousal). The results further indicated an overall improvement in behavioral (as evidenced by the decrease in ART and VRT) and cognitive performances (as evidenced by increase in the P300 amplitude and decrease in the P300 latency) in medical students in the exercise session relative to the baseline session despite bidirectional shifts in valence suggesting that interdependent neural systems might mediate these effects.

Effect of a Moderate-Intensity Aerobic Exercise on Estimates of Egocentric Distance

The goal was to explore the effect of a moderate-intensity exercise on egocentric distance estimates (the distance between the participant and an object in space) in physically trained and untrained participants ( N = 54), divided into three groups of 18 national-level soccer players, 18 sedentary people, and 18 controls. Participants engaged in a distance estimation task at rest, and also while pedalling on an ergocycle for 10 min. at 60% of the maximal aerobic intensity. Estimates were recorded during pre-exercise, stability Phase 1 (between the 1st and the 2nd min. of exercise), Phase 2 (5th to 6th min.), Phase 3, (9th to 10th min.), and immediately after the exercise. Estimates of egocentric distance were more accurate in trained than untrained participants. Perception improved during and after the exercise in comparison with pre-exercise. In addition, the group x exercise interaction indicated estimation improved during and after exercise, with more accuracy in the trained than untrained participants. Fitness and moderate aerobic exercise improve the egocentric distance estimation in humans.

The effects of acute exercise on cognitive performance: a meta-analysis

There is a substantial body of literature related to the effects of a single session of exercise on cognitive performance. The premise underlying this research is that physiological changes in response to exercise have implications for cognitive function. This literature has been reviewed both narratively and meta-analytically and, although the research findings are mixed, researchers have generally concluded that there is a small positive effect. The purpose of this meta-analysis was to provide an updated comprehensive analysis of the extant literature on acute exercise and cognitive performance and to explore the effects of moderators that have implications for mechanisms of the effects. Searches of electronic databases and examinations of reference lists from relevant studies resulted in 79 studies meeting inclusion criteria. Consistent with past findings, analyses indicated that the overall effect was positive and small (g=0.097 n=1034). Positive and small effects were also found in all three acute exercise paradigms: during exercise (g=0.101; 95% confidence interval [CI]; 0.041-0.160), immediately following exercise (g=0.108; 95% CI; 0.069-0.147), and after a delay (g=0.103; 95% CI; 0.035-0.170). Examination of potential moderators indicated that exercise duration, exercise intensity, type of cognitive performance assessed, and participant fitness were significant moderators. In conclusion, the effects of acute exercise on cognitive performance are generally small; however, larger effects are possible for particular cognitive outcomes and when specific exercise parameters are used.

Effects of acute exercise on long-term memory

In this study, we tested the effect of acute exercise on long-term memory, specifically the timing of exercise relative to the memory challenge. We assessed memory via paragraph recall, in which participants listened to two paragraphs (exposure) and recounted them following a 35-min delay. Participants (n = 48) were randomly assigned to one of three groups: exercise prior to exposure, exercise after exposure, or no-exercise. Exercise consisted of 30 min on a cycle ergometer including 20 min at moderate intensity. Only the exercise prior group recalled significantly more than the control group (p < .05). Differences among the exercise groups failed to reach significance (p = .09). Results indicated that acute exercise positively influenced recall and that exercise timing relative to memory task may have an impact on this effect.

The reticular-activating hypofrontality (RAH) model of acute exercise

We present here a comprehensive, neurocognitive model to account for the psychological consequences of acute exercise. There is a substantial amount of disparate research and the proposed mechanistic explanation meaningfully integrates this body of brain and behavioral data into a single, unified model. The model's central feature is a cascading, two-step process. First, exercise engages arousal mechanisms in the reticular-activating system. This activation process, which involves a number of neurotransmitter systems, has several interrelated effects on cognition and emotion but, in general, has evolved to facilitate implicit information processing. Second, exercise disengages the higher-order functions of the prefrontal cortex. This deactivation process, which is caused in part by resource limitations, also has several interrelated effects but, in general, has evolved to keep the inefficient explicit system and unhelpful emotional processes from compromising the implicit system's functioning when optimal motor execution is needed most. In this article, we review evidence in support of this reticular-activating hypofrontality (RAH) model of acute exercise and place it into a larger evolutionary context.

Fitness’s Moderation of the Facilitative Effect of Acute Exercise on Cognitive Flexibility in Older Women

A recent study indicated that acute aerobic exercise improves cognitive flexibility in adults. The current study assessed age, habitual physical activity, and physical fitness as moderators of this improvement and examined whether the gains still exist an hour after the exercise session. The alternative-uses test, assessing cognitive flexibility, was administered individually to 20 older (age 63.67 ± 3.55 yr) and 19 young (age 23.9 ± 1.22) women before, immediately after, and an hour after a single moderate aerobic-exercise session. Results indicated significant improvement in cognitive flexibility in the older group immediately after the exercise but a decrease at the 1-hr follow-up. Further analysis indicated that physical fitness accounted for this improvement (R= –.622,p< .01). No such differences were observed in the young group. Further studies are needed to examine the duration of this effect, as well as the role of physical fitness as a moderator of it.

Exploring the relationship between exercise-induced arousal and cognition using fractionated response time

Although a generally positive effect of acute exercise on cognitive performance has been demonstrated, the specific nature of the relationship between exercise-induced arousal and cognitive performance remains unclear This study was designed to identify the relationship between exercise-induced arousal and cognitive performance for the central and peripheral components of a response time task at two different levels of task difficulty. Sixteen male participants performed both simple and choice response time tasks at eight different arousal levels (from 20% to 90% heart rate reserve). Performance on the simple and choice response time tasks was examined after fractionating the response time into its central component, premotor time, and peripheral components, motor, and movement time. A priori trend analysis was used to test both linear and quadratic relationships. Results indicated that exercise-induced arousal has a positive influence on the peripheral components of response time tasks; however it has a limited impact on the central components of these tasks.

Reaction time to peripheral visual stimuli during exercise under normoxia and hyperoxia

The purpose of this study was to test if increased oxygen availability affected simple reaction time (RT) to peripheral visual stimuli during exercise. Twelve male participants performed RT tasks at rest, during cycling with three different workloads (100, 150, and 200 W), and after exercise. We fractionated RT into Premotor time and Motor time. Under normoxia, Premotor time significantly increased during exercise at 200 W (mean +/- SD, 224.7 +/- 34.8 ms) relative to that at rest (213.3 +/- 34.1 ms) (P < 0.05). In contrast, we found no difference in Premotor time between at rest (214.0 +/- 27.0 ms) and at 200 W (213.0 +/- 21.6 ms) under hyperoxia. Furthermore, Premotor time significantly decreased at 150 W (201.3 +/- 22.4 ms) relative to that at rest under hyperoxia (P < 0.05). These results suggest that increased oxygen availability during exercise has beneficial effects on perceptual performance.

Acute aerobic exercise and information processing: energizing motor processes during a choice reaction time task

The immediate and short-term after effects of a bout of aerobic exercise on young adults' information processing were investigated. Seventeen participants performed an auditory two-choice reaction time (RT) task before, during, and after 40 min of ergometer cycling. In a separate session, the same sequence of testing was completed while seated on an ergometer without pedalling. Results indicate that exercise (1) improves the speed of reactions by energizing motor outputs; (2) interacts with the arousing effect of a loud auditory signal suggesting a direct link between arousal and activation; (3) gradually reduces RT and peaks between 15 and 20 min; (4) effects on RT disappear very quickly after exercise cessation; and (5) effects on motor processes cannot be explained by increases in body temperature caused by exercise. Taken together, these results support a selective influence of acute aerobic exercise on motor adjustment stage.

The effect of a single session submaximal aerobic exercise on premotor fraction of reaction time: an electromyographic study

BACKGROUND

Numerous studies investigating the effect of exercise on reaction time have yielded contradictory results. Most of the studies use computer based methods to measure reaction time instead of electromyography, yielding total reaction time rather than premotor time. In this study, we aimed to investigate the effect of a single session aerobic exercise on premotor fraction of reaction time in sedentary healthy individuals.

METHODS

Twenty-two sedentary healthy subjects (11 subjects for the study group and 11 for the control group) enrolled in this study. Subjects in the exercise group performed a single session submaximal cycling exercise. Electromyographic reaction times were measured before and after the exercise session. In the control group, reaction time measurements were taken twice with an interval of 20 min.

FINDINGS

In the exercise group, premotor fraction of reaction time values decreased considerably (P=0.01) after the exercise session.

INTERPRETATION

A single bout of cycling exercise significantly improved premotor fraction of reaction time in healthy young sedentary subjects. Physical activity improves not only physical fitness but also cognitive functions. Electromyographic reaction time evaluations may be used in the sports medicine field where both aerobic fitness and short reaction time are indispensable demands.

Focusing of visual attention at rest and during physical exercise in soccer players

In this study, we investigated the focus of visual attention in expert soccer players together with the effects of acute bouts of physical exercise on performance. In two discriminative reaction time experiments, which were performed both at rest and under submaximal physical workload, visual attention was cued by means of spatial cues of different size followed by compound stimuli with local and global target features. Soccer players were slower than non-athletes in reacting to local compared with global targets, but were faster in switching from local to global attending. Thus, soccer players appear to be less skilled in local attending, but better able than non-athletes to rapidly "zoom out" the focus of attention. Non-athletes generally showed faster performance under physical load, as expected according to the hypothesis of exercise-induced increases in arousal and/or activation and in resource allocation. In contrast, soccer players showed a more differentiated pattern of exercise-induced facilitation that selectively affects specific components of the attentional performance and is interpreted by referring to the role played by individual expertise and cognitive effort.

Perceptual visual skills in young highly skilled basketball players

A simple method was designed to evaluate visual abilities such as disance visual acuity, binocular horizontal visual field, simple and choice visual reaction times, and stereoscopic vision in skilled 11- to 13-yr.-old basketball players participating in a 15-day summer training camp. On a test battery, visual abilities were monitored in 473 players of the Spanish Basketball Federation over a 5-yr. period. The players showed outstanding scores on distance visual acuity and stereoscopic vision, and good visual reaction times and horizontal visual fields. When scores were compared by sex and age, significant differences on certain visual measures were observed. Many layers showed crossed eye-hand dominance. Visual screening programs may help promote visual health among junior basketball players and could be used for performance training.

Neuroelectric and behavioral indices of interference control during acute cycling

OBJECTIVE

This study examined the effects of in-task, moderate-intensity aerobic exercise on neuroelectric and behavioral indices of interference control, one component of executive control.

METHODS

Forty-one participants completed a V O(2) max test to determine maximal heart rate (HR). On a separate day, event-related brain potentials and task performance were measured during the counterbalanced conditions of upright cycling at 60% of maximal HR and rest while performing congruent and incongruent trials of a flanker task.

RESULTS

Exercise resulted in reduced response accuracy for incongruent trials relative to rest; an effect not found for congruent trials. Decreased N1 amplitude was observed during exercise at parietal sites and globally for N2. Exercise also resulted in increased amplitude for the P2 at frontal and central sites, and for the P3 at frontal and lateral sites. Further, longer N2 and P3 latencies were observed during exercise relative to rest.

CONCLUSION

These findings suggest that the need to allocate attentional resources toward the large-scale bodily movements inherent in exercise may relate to inefficiency of neural resource allocation, resulting in decreased interference control.

SIGNIFICANCE

These data indicate general and selective exercise-induced decrements in cognitive processing while performing acute aerobic exercise.

A distributional analysis of the effect of physical exercise on a choice reaction time task

The aim of this study was to examine the facilitating effects of physical exercise on the reaction process. Eleven participants with specific expertise in decision-making sports performed a choice reaction time task during moderate sub-maximal exercise (90% of their ventilatory threshold power). Participants were tested at rest and while cycling. During exercise, the participants were faster, without being more variable. We suggest that the effect of exercise on cognitive performance was due to a major generalized improvement of the whole distribution of response time and, although the benefit effect was small, it was consistent throughout the entire range of reaction times.

Information processing during physical exercise: a chronometric and electromyographic study

Choice reaction time (RT) is shorter when participants perform a choice task at the same time as a sub-maximal exercise than when they are at rest. The purpose of the present study was to determine whether such an exercise affects response execution or whether it alters processes located upstream from the neuro-muscular level. To this end, the electromyographic (EMG) activity of the response agonists was analysed in a between-hand choice RT task performed either concurrently with a pedalling task or at rest. Visual stimulus intensity was also manipulated so as to determine whether exercise further affects early sensory processes. Results shows that exercise affected the time interval elapsing from the onset of the contraction of the response agonists to the mechanical response, thereby indicating that this variable modifies the peripheral motor processes involved in response execution. EMG signal analyses further revealed that the cortico-spinal command is more efficient during exercise than at rest. In addition, exercise was shown to interact with visual stimulus intensity on the time between stimulus and voluntary EMG onset and to increase the critical flicker fusion frequency threshold, thereby indicating that exercise modifies the peripheral sensory processes involved in early sensory operations. The decomposition of RT, with respect to the EMG activity of response agonists, sheds light on the processes affected by exercise and suggests that exercise affects both sensory processes and late motor processes.

Endurance exercise selectively impairs prefrontal-dependent cognition

Two experiments are reported that examine the possibility that exercise selectively influences different types of cognition. To our knowledge, these experiments represent the first attempt to study higher-cognitive processes during exercise. Theoretical thinking was guided by the transient hypofrontality hypothesis. In both experiments, athletes who exercised at a sustained, moderate pace were compared to sedentary controls on two neuropsychological tests, one that is generally regarded as heavily dependent on prefrontal cognition and one that is relatively insensitive to prefrontal operation. Results showed that during exercise performance on tests demanding prefrontal-dependent cognition was impaired, while at the same time, cognitive processes requiring little prefrontal activity were unaffected.

Serum testosterone, growth hormone, and insulin-like growth factor-1 levels, mental reaction time, and maximal aerobic exercise in sedentary and long-term physically trained elderly males

The aim of the study was to investigate the effect of regular exercise on maximum oxygen uptake capacity (VO2max), reaction time (RT), testosterone (T), growth hormone (GH), insulin-like growth factor-I (IGF-I) in athletes compared to sedentary controls. VO2max, RT, T, GH, and IGF-I levels were 31.2 +/- 6.2 ml/min/kg, 106.7 +/- 23.2 s, 8.3 +/- 1.3 ng/mL, 1.6 +/- 0.7 ng/mL, 106.5 +/- 27.0 ng/mL in master athlete group and 18.8 +/- 5.1 ml/min/kg, 148.3 +/- 39.3 s, 5.4 +/- 1.7 ng/mL, 0.8 +/- 0.3 ng/mL, 90.2 +/- 23.8 ng/mL in sedentary control group, respectively. The differences between regularly exercising males and the control group of sedentary males were found to be statistically significant. The results showed that long-term exercise decreased RT and increased VO2max, T, and GH in elderly males; elevated serum T and GH levels may be advantageous for brain functions.

Facilitating effects of exercise on information processing

The aim of this study was to examine the facilitating effects of moderate physical exercise on the reaction process to gain a better understanding of the interaction between physiological and cognitive processes. Sixteen participants with specific expertise in decision-making sports performed a double task consisting of choice reaction time while cycling. Signal quality, stimulus-response compatibility and time uncertainty were manipulated. Participants were tested at rest and while cycling at 20% and at 50% of their maximal aerobic power. A mood assessment questionnaire and a critical flicker fusion test were administered before and after the choice reaction time task. The results showed that moderate-intensity exercise (50% maximal aerobic power) improves cognitive performance and that low-intensity exercise (20% maximal aerobic power) enables participants to compensate the negative dual-task effect.

Effect of Slow Movement Execution on Cognitive Function

We investigated the effect of slow paced movement on cognitive function. The task movement was a dual-task performance composed of a continuous forearm rotation for the right hand and a simple reaction task for the left hand. Exp. 1 was designed to compare reaction time during performance at a slow pace to that at medium pace by 14 female undergraduate students. The mean reaction time for the left hand under the Slow Pace was significantly longer than that under the Middle Pace condition ( p<.05), which showed that the subjects were required to give more attention to right-hand performance at the slow pace as it was difficult. Exp. 2 examined changes in reaction time when using the left hand that were associated with the learning of a slow paced task while using the right hand. Twenty-three female undergraduate students participated and repeated the task 6 times. The 3 sec. prior to and the 3 sec. after each auditory stimulus were used to establish rotation speed and mean coefficients of variation. The mean coefficients of variation, evaluated as within-subject variability, showed a significantly positive correlation with reaction time at Trials 1 and 6 for prestimulus and Trials 5 and 6 for poststimulus. Over successive trials participants continued performing the primary forearm task at a constant slow pace before and after receiving auditory stimuli, and this progress was related to a decrease in reaction time. Further, the sense of concentration evaluated by the subjects poststimulus was significantly higher than that prestimulus ( p<.01). Performance at a constant speed, which was much slower than the ordinary or preferred speed of each subject, may have had a strong effect on their ability to remain conscious of movement execution.

Effects of acute bouts of exercise on cognition

A review was conducted of studies that assessed the effects of acute bouts of physical activity on adults' cognitive performance. Three groups of studies were constituted on the basis of the type of exercise protocol employed. Each group was then evaluated in terms of information-processing theory. It was concluded that submaximal aerobic exercise performed for periods up to 60 min facilitate specific aspects of information processing; however, extended exercise that leads to dehydration compromises both information processing and memory functions. The selective effects of exercise on cognitive performance are explained in terms of Sanders' [Acta Psychol. 53 (1983) 61] cognitive-energetic model.

Effects of acute physical exercise characteristics on cognitive performance

The effect of physical exercise on mental function has been widely studied from the beginning of the 20th century. However, the contradictory findings of experimental research have led authors to identify several methodological factors to control in such studies including: (i) the nature of the psychological task; and (ii) the intensity and duration of physical exercise. The purpose of this article is to provide information, from the perspective of performance optimisation, on the main effects of physical task characteristics on cognitive performance. Within this framework, some consistent results have been observed during the last decade. Recent studies, using mainly complex decisional tasks, have provided the research community with clear support for an improvement of cognitive performance during exercise. Diverse contributing factors have been suggested to enhance cognitive efficacy. First, an increase in arousal level related to physical exertion has been hypothesised. Improvement in decisional performance has been observed immediately after the adrenaline threshold during incremental exercise. Such positive effects could be enhanced by nutritional factors, such as carbohydrate or fluid ingestion, but did not seem to be influenced by the level of fitness. Second, the mediating role of resource allocation has been suggested to explain improvement in cognitive performance during exercise. This effect highlights the importance of motivational factors in such tasks. Finally, when the cognitive performance was performed during exercise, consistent results have indicated that the dual task effect was strongly related to energetic constraints of the task. The greater the energy demand, the more attention is used to control movements.

Effects of a prolonged run on simple reaction time of well trained runners

The aim of the present study was to examine the effect of increased arousal induced by a prolonged exercise at ventilatory threshold simple reaction time performance performed during a running task. 11 well trained triathletes completed two testing sessions within a 2-wk. period. The first session was a protocol of VO2 max determination conducted on a treadmill. This protocol was used to assess the velocity associated with ventilatory threshold (vVvt). The second session was a 90-min. running test performed at vVvt. This last session was composed of five submaximal treadmill runs (10-min. long, 0% grade) separated by four overground runs (10-min.). Before, during each treadmill run, and after exercise, subjects performed three blocks of 20 simple reaction time. Furthermore, at the end of each overground run, perceived exertion (RPE) was recorded. Analysis showed a significant impairment in Simple RT performance during the first treadmill run only. After this first run a significant effect of exercise duration on Simple RT was observed. After 40-min. of exercise a significant improvement in reaction time during exercise was recorded, Furthermore, when Simple RT was recorded at rest, there was no difference pre-exercise and postexercise. These results suggest that a simple cognitive performance could be improved during exercise, despite the negative effect of the dual task. This improvement in reaction time could be explained mainly by an increase in arousal induced by a prolonged exercise.

Performance stability in simultaneous tasks of pedalling and reaction time

The purpose of the study was to examine the within-subject variability in heart rate, pedal rate, choice reaction time, and error rate during simultaneous tasks of cycling and reaction time. Students in physical education classes exercised a 10-min. submaximal cycloergometer test at a relative power output corresponding to 60% of their own maximal aerobic power, in a replication procedure. Concomitantly, the subjects performed a 2-choice reaction time task from Min. 3 of the exercise bout. No significant differences (p > .05) were found between the individual means in the tests for the diverse parameters. The total intraindividual variability averaged 1.3% for heart rate, 2.2% for pedal rate, and 13.3% for choice reaction time. Because wide within-subject variability was observed (from 7.7 to 16.7%), the reliability of choice reaction time was low. These data suggest that it is necessary to quantify more accurately the intraindividual differences of reaction time measures for the interpretation of exercise-changes in cognitive functioning.