The relationship of aerobic fitness with verbal and spatial working memory: An ERP study.

Working memory (WM) plays an important role in daily life and is known to correlated with aerobic fitness. However, whether the relationship between aerobic fitness and WM is dependent on the stimulus modality or is associated with one or multiple subprocesses involved in WM remains unknown. Accordingly, this study utilized event-related potentials (ERPs) to comprehensively examine the encoding, preparation, and retrieval processes during verbal and spatial WM performance. Eighty-eight young adults aged 18-30years were recruited to participate in two laboratory visits on separate days. On day 1, aerobic fitness was assessed by maximum oxygen consumption (V˙O2max) during a treadmill-based graded exercise test. On day 2, participants completed verbal and spatial WM tasks while P2, contingent negative voltage (CNV), and P3 components of ERP were recorded during the encoding, preparatory, and retrieval stages of WM, respectively. Results of hierarchical regression analysis showed that V˙O2max was positively correlated with response accuracy during the high-demanding condition of spatial WM after controlling for age, sex, and self-reported physical activity. Additionally, a higher level of V˙O2max was associated with larger terminal CNV amplitude at the Cz electrode during the high-demanding condition of spatial WM. These findings suggest that aerobic fitness may have selective beneficial associations with the motor preparatory process and subsequent task performance requiring a greater amount of spatial information but not the encoding and retrieval stages nor the verbal modality of WM.

Intermuscular coherence as an early biomarker for amyotrophic lateral sclerosis: The protocol for a prospective, multicenter study.

OBJECTIVE: To describe the protocol of a prospective study to test the validity of intermuscular coherence (IMC) as a diagnostic tool and biomarker of upper motor neuron degeneration in amyotrophic lateral sclerosis (ALS). METHODS: This is a multicenter, prospective study. IMC of muscle pairs in the upper and lower limbs is gathered in ∼650 subjects across three groups using surface electrodes and conventional electromyography (EMG) machines. The following subjects will be tested: 1) neurotypical controls; 2) patients with symptomatology suggestive for early ALS but not meeting probable or definite ALS by Awaji Criteria; 3) patients with a known ALS mimic. The recruitment period is between 3/31/2021 and 12/31/2025. Written consent will be sought from the subject or the subject's legally authorized representative during enrollment. RESULTS: The endpoints of this study include: 1) whether adding IMC to the Awaji ALS criteria improve its sensitivity in early ALS and can allow for diagnosis earlier; 2) constructing a database of IMC across different ages, genders, and ethnicities. SIGNIFICANCE: This study may validate a new inexpensive, painless, and widely available tool for the diagnosis of ALS.

Added load increases the peak frequency of intermuscular coherence.

Cortical motor neuron activity appears to drive lower motor neurons through two distinct frequency bands: the ß range (15-30 Hz) during weak muscle contractions and γ range (30-50 Hz) during strong contractions. It is unknown whether the frequency of cortical drive shifts continuously or abruptly between the ß and γ frequency bands as contraction strength changes. Intermuscular coherence (IMC) between synergistic arm muscles was used to assess how the frequency of common neuronal drive shifts with increasing contraction strength. Muscle activity was recorded by surface electromyography (EMG) from the biceps and brachioradialis in nine healthy adults performing 30-second isometric holds with added loads. IMC was calculated across the two muscle groups during the isometric contraction. Significant IMC was present in the 20 to 50 Hz range with all loads. Repeated measures ANOVA show the peak frequency of IMC increased significantly when load was added, from a peak of 32.7 Hz with no added load, to 35.3 Hz, 35.7 Hz, and 36.3 Hz with three-, five-, and ten-pound loads respectively. An increase in IMC frequency occurs in response to added load, suggesting that cortical drive functions over a range of frequencies as a function of an isometric contraction against load.

Size or Strength? how components of muscle relate to behavioral and neuroelectric measures of executive function independent of aerobic fitness.

While previous research has linked cognitive function with resistance exercise, the nuanced links between muscle strength, mass, and neuroelectric function are less understood. Therefore, this study investigated the association of muscle strength and mass with inhibitory control (IC), working memory (WM), and related neuroelectric activity. A total of 123 18-50-year-old adults completed maximal aerobic capacity and strength tests, a body composition scan, and IC and WM tasks while the N2 and P3 components of event-related potentials were recorded. Bivariate correlations revealed aerobic fitness, strength, and mass were associated with behavioral and neuroelectric outcomes. After accounting for age, sex, and aerobic fitness, strength was associated with intra-individual response time variability, accuracy, and P3 latency during WM. Muscle mass was associated with N2 latency during IC. While relationships with behavioral outcomes did not persist after controlling for the opposite muscle outcome, greater strength and mass were related to shorter P3 latency during WM and shorter N2 latency during IC, respectively. These results provide initial evidence that muscle outcomes are associated with executive function and neuroelectric processing speed, suggesting distinct contributions of strength and mass to cognition. This work highlights the significance of maintaining muscle strength and mass alongside aerobic fitness for optimal cognitive health.

Mindfulness induction and executive function after high-intensity interval training with and without mindful recovery intervals.

OBJECTIVES: Determine the effect of incorporating mindfulness-based activities into the recovery intervals of high-intensity interval training (HIIT) on mindfulness induction and subsequent executive function performance. DESIGNS: A within-subject crossover trial. METHODS: Forty adults participated in two experimental conditions, including a 30-min bout of HIIT involving mindfulness recovery intervals (Mindful) and a 30-min bout of HIIT without mindfulness recovery intervals (Non-mindful), on two separate days in counterbalanced order. Before and after each condition, participants completed the flanker task, switch-flanker task, and n-back task to measure inhibitory control, cognitive flexibility, and working memory, respectively. RESULTS: A higher level of mindfulness state was observed following the Mindful condition than the Non-mindful condition. Dispositional mindfulness was positively correlated with the level of the mindful state only during the Mindful condition but not the Non-mindful condition. The switch-flanker response accuracy was improved from the pretest to posttest during the Non-mindful condition but remained unchanged over time during the Mindful condition. Time-related improvements in the flanker and n-back task outcomes were observed for both the Mindful and Non-mindful conditions and did not differ between conditions. CONCLUSION: Although incorporating mindfulness-based activities during the recovery intervals of HIIT successfully led to greater state-related mindfulness, such a heightened mindful state did not correspond with additional modulation in inhibitory control and working memory performance while attenuating HIIT-related positive changes in task performance requiring cognitive flexibility.

Intermuscular Coherence in Spinocerebellar Ataxias 3 and 6: a Preliminary Study.

Spinocerebellar ataxias (SCAs) are familial neurodegenerative diseases involving the cerebellum and spinocerebellar tracts. While there is variable involvement of corticospinal tracts (CST), dorsal root ganglia, and motor neurons in SCA3, SCA6 is characterized by a pure, late-onset ataxia. Abnormal intermuscular coherence in the beta-gamma frequency range (IMCßγ) implies a lack of integrity of CST or the afferent input from the acting muscles. We test the hypothesis that IMCßγ has the potential to be a biomarker of disease activity in SCA3 but not SCA6. Intermuscular coherence between biceps brachii and brachioradialis muscles was measured from surface EMG waveforms in SCA3 (N = 16) and SCA6 (N = 20) patients and in neurotypical subjects (N = 23). IMC peak frequencies were present in the ß range in SCA patients and in the γ range in neurotypical subjects. The difference between IMC amplitudes in the γ and ß ranges was significant when comparing neurotypical control subjects to SCA3 (p < 0.01) and SCA6 (p = 0.01) patients. IMCßγ amplitude was smaller in SCA3 patients compared to neurotypical subjects (p < 0.05), but not different between SCA3 and SCA6 patients or between SCA6 and neurotypical subjects. IMC metrics can differentiate SCA patients from normal controls.

Protective effect of aerobic fitness on the detrimental influence of exhaustive exercise on information processing capacity.

Although aerobic fitness has been thought to protect against the detrimental cognitive effects following exhaustive exercise, available evidence from studies using traditional mean behavioral measures remain somewhat equivocal. PURPOSE: This study aimed to reconcile this discrepancy by using a novel theory-driven diagnostic tool, the Systems Factorial Technology (SFT). METHODS: Sixty-six healthy young adults aged from 18 to 30 years old with different levels of aerobic fitness (n = 33 for the higher-fit and lower-fit groups) completed a go/nogo version of redundant-target task before and after a graded exercise test (GXT) until exhaustion. SFT was used to calculate the resilience capacity, which reflects the information processing capacity underlying inhibitory control. RESULTS: Following the GXT, both higher-fit and lower-fit groups showed faster responses while leaving accuracy unchanged as compared to the performance at the pretest. On the other hand, the resilience capacity decreased for the lower-fit group but was maintained for the higher-fit group. CONCLUSION: The present findings suggest that aerobic fitness may modulate the individual difference in decisional mechanism following exhaustive exercise. In sum, this study offers an alternative mechanistic explanation regarding cognitive individual differences in response to exhaustive exercise and provides novel insights into the significance of maintaining a state of high physical fitness for those who need to perform cognitively challenging tasks under physically stressful conditions (e.g., elite athletes).

Acute effects of mindful interval exercise on cognitive performance in a higher education setting.

Interval exercise (IE) has been shown to have acute facilitating effects on cognition; however, the existing literature has been limited to laboratory settings and has focused on manipulating the parameters of exercise bouts during IE. This study included two classroom-based experiments to (1) investigate the effect of an acute bout of IE delivering mindfulness activity during its recovery intervals (mindful IE) on cognitive performance, and (2) compare cognitive performance following acute bouts of mindful IE with non-mindful IE. Experiment 1: Using a class-based within-subject crossover design, 59 participants completed the Stroop, d2, and trail-making tests to measure inhibitory control, attention, and cognitive flexibility, after a 30-min non-exercise or mindful IE session on separate counterbalanced days. Experiment 2: Using a similar design, 70 participants were assigned to two groups to receive a non-exercise and an IE session with (mindful) or without (non-mindful) mindfulness-based recovery intervals on separate counterbalanced days. Results from Experiment 1 showed superior d2 performance following the mindful IE than the non-exercise session. Although Experiment 2 found exercise-related decreases in commission error rate during the d2 test in both groups, the non-mindful group showed additional decreases in omission and total error rates. Further, higher scores on the nonreactivity facet of dispositional mindfulness were correlated with larger decreases in omission and total error rates during the d2 test for the mindful IE group. No exercise-related effect was found for outcomes of the Stroop and trail-making tests in both experiments. These findings in the selective improvements in d2 test performance are the first to suggest the feasibility of integrating mindfulness activity into the recovery intervals of IE for enhanced cognitive performance that may depend on individual differences in dispositional mindfulness.

Acute effects of intense interval versus aerobic exercise on children's behavioral and neuroelectric measures of inhibitory control.

OBJECTIVES: Determine the acute effect of high-intensity interval training as an alternative of moderate-intensity aerobic exercise on behavioral and neuroelectric measures of inhibitory control in preadolescent children. DESIGN: A randomized controlled trial. METHODS: Seventy-seven children (8-10 years) were randomly assigned to three groups to complete a modified flanker task to measure behavioral and neuroelectric (N2/P3 of event-related potential and frontal theta oscillations) outcomes of inhibitory control before and after a 20-min session of high-intensity interval training (N = 27), moderate-intensity aerobic exercise (N = 25), and sedentary reading activity (N = 25). RESULTS: The accuracy of the inhibitory control performance improved over time across three groups but response time was selectively improved only for the high-intensity interval training group. Analysis on N2 showed a time-related decrease in N2 latency selectively for the high-intensity interval training but not the other groups. Analysis on P3 showed a time-related decrease in P3 amplitude for the sedentary and high-intensity interval training groups while the moderate-intensity aerobic exercise group exhibited maintained P3 amplitude from the pretest to the posttest and a larger P3 amplitude compared with the high-intensity interval training group at the posttest. While there was evidence of conflict-induced modulation of frontal theta oscillations, such an effect was unaffected by exercise interventions. CONCLUSIONS: A single bout of high-intensity interval training has facilitating effects on the processing speed involving inhibitory control in preadolescent children but not neuroelectric index of attention allocation that only benefited from moderate-intensity aerobic exercise.

Intermuscular coherence in spinocerebellar ataxias 3 and 6: a preliminary study.

Objective : Spinocerebellar ataxias (SCAs) are familial neurodegenerative diseases involving the cerebellum and spinocerebellar tracts. While there is variable involvement of corticospinal tracts (CST), dorsal root ganglia, and motor neurons in SCA3, SCA6 is characterized by a pure, late-onset ataxia. Abnormal intermuscular coherence in the beta-gamma frequency range (IMCbg) implies lack of integrity of CST or the afferent input from the acting muscles. We test the hypothesis that IMCbg has the potential to be a biomarker of disease activity in SCA3 but not SCA6. Methods: Intermuscular coherence between biceps and brachioradialis muscles was measured from surface EMG waveforms in SCA3 (N=16) and SCA6 (N=20) patients, and in neurotypical subjects (N=23). Results: IMC peak frequencies were present in the b range in SCA patients and in the g range in neurotypical subjects. The difference between IMC amplitudes in the g and b ranges was significant when comparing neurotypical control subjects to SCA3 (p < 0.01) and SCA6 (p = 0.01) patients. IMCbg amplitude was smaller in SCA3 patients compared to neurotypical subjects (p<0.05), but not different between SCA3 and SCA6 patients or between SCA6 and neurotypical subjects. Conclusion/significance: IMC metrics can differentiate SCA patients from normal controls.

Acute effects of aerobic exercise on conflict suppression, response inhibition, and processing efficiency underlying inhibitory control processes: An ERP and SFT study.

Aerobic exercise has been identified as an effective strategy for transiently enhancing inhibitory control, an ability to suppress irrelevant distractors while focusing on relevant information in facilitating the implementation of goal-directed behavior. The purpose of this study was to employ a go/no-go version of the redundant-target task and event-related potential to further determine whether inhibitory control at the perceptual and response levels as well as their underlying processing capacity and neuroelectric alterations are differentially affected by a single bout of aerobic exercise. Twenty-seven young adults completed the redundant-target task while electroencephalogram was recorded before and after one 20-min bout of moderate-intensity aerobic exercise and a sitting control condition on separate days in counterbalanced order. Although behavioral outcomes of mean-level performance did not differ between intervention conditions, time-related decreases in processing capacity for the faster responses were only observed following rest. Aerobic exercise resulted in maintained P3b amplitude from pretest to posttest for all trial types while decreased P3b amplitude from pretest to posttest during single-target and redundant-target trials was observed following rest. Further, the time-related changes in P3b amplitude were positively correlated with improvements in task performance following exercise. These findings suggest that a short bout of aerobic exercise selectively counteracts the time-related decrements in processing capacity as well as neuroelectric processing of attention and conflict suppression that contribute to behavioral outcomes of inhibitory control.

School Lunch Timing and Children's Physical Activity During Recess: An Exploratory Study.

OBJECTIVE: To examine the relationship between school lunch timing (before vs after recess) on physical activity (PA) during recess and energy balance and food intake at lunch. METHODS: A cross-sectional study design was used to examine lunch intake and PA during recess among fourth- and fifth-graders (n = 103) over 5 school days. Lunch and PA were measured using a weighted plate waste technique and accelerometry, respectively. RESULTS: Children who received lunch before recess accumulated lower residual energy (ie, energy intake at lunch minus energy expenditure during recess) and consumed a greater proportion of milk servings. No timing effects were observed for other lunch and PA variables. CONCLUSIONS AND IMPLICATIONS: Lunch intake and activity during recess are related to lunch timing policy. Findings warrant further examination using experimental and quasi-experimental studies to better understand the impact of timing on health behaviors.

Relationship Between Physical Activity, Adiposity, and Attentional Inhibition.

BACKGROUND: Physical inactivity and excess adiposity are thought to be detrimental to physical and cognitive health. However, implications of these interrelated health factors are rarely examined together; consequently, little is known regarding the concomitant contribution of physical activity and adiposity to cognition. METHODS: Bivariate correlations and hierarchical linear regressions were conducted among a sample of adults between 25 and 45 years (N = 65). Attentional inhibition was assessed using an Eriksen Flanker task. Whole-body percent body fat (%Fat) was assessed using dual-energy X-ray absorptiometry. Daily percent time spent in moderate to vigorous physical activity (%MVPA) was monitored using an accelerometer (7 d). RESULTS: After adjusting for significant covariates, %MVPA was a positive predictor of accuracy in the incongruent task (ß = 0.31, P = .03). Individuals who engaged in greater %MVPA exhibited superior attentional inhibition. Additionally, there was an interaction effect of %Fat and %MVPA on attentional inhibition (ß = 0.45, P = .04). CONCLUSION: The positive influence of MVPA on cognitive control persists following the adjustment of significant covariates and adiposity. Additionally, interactive effects between %Fat and %MVPA suggest that individuals with lower activity and greater adiposity exhibited poorer attentional inhibition. These findings have relevance for public health given the elevated rates of physical inactivity and obesity.

Effectiveness of a 16-Week High-Intensity Cardioresistance Training Program in Adults.

Greenlee, TA, Greene, DR, Ward, NJ, Reeser, GE, Allen, CM, Baumgartner, NW, Cohen, NJ, Kramer, AF, Hillman, CH, and Barbey, AK. Effectiveness of a 16-week high-intensity cardioresistance training program in adults. J Strength Cond Res 31(9): 2528-2541, 2017-The purpose of this study was to determine the efficacy of a novel, 16-week high-intensity cardioresistance training (HICRT) program on measures of aerobic fitness, agility, aerobic power, muscular endurance, lower-body explosive power, and self-reported activity level. The intervention group (N = 129; 63 f, 24.65 ± 5.55 years) had a baseline V[Combining Dot Above]O2max of 39.83 ± 9.13. These individuals participated in 26, 70-minute exercise sessions, and 4 fitness testing sessions. Participants were matched with a nonexercise control group, paired by sex, age, and baseline V[Combining Dot Above]O2max. Matched controls (N = 129, 63 f, 24.26 ± 5.59 years) had a baseline V[Combining Dot Above]O2max of 39.86 ± 8.59 and completed preintervention and postintervention V[Combining Dot Above]O2max testing only. The results demonstrate that participants in the fitness intervention group significantly increased their V[Combining Dot Above]O2max (2.72 ± 0.31, Mdiff ± SE; p < 0.001) and reported being more physically active (0.42 ± 0.11, Mdiff ± SE; p < 0.001) after the intervention. The matched control group showed no significant pre-post intervention changes. Participants in the fitness intervention showed a significant improvement in 3 of 5 components of the fitness field tests. Specifically, significant improvements were observed for the 1-minute rower (5.32 ± 0.505, Mdiff ± SE; p < 0.001), 1-minute push-up (8.168 ± 0.709, Mdiff ± SE; p < 0.001), and 1.5-mile run tests (1.79 ± 0.169, Mdiff ± SE; p < 0.001). No significant improvements were observed for the shuttle run (p = 0.173) or standing long jump (p = 0.137). These findings demonstrate the efficacy of a novel, HICRT intervention across multiple dimensions of fitness for young- and middle-aged adults. High-intensity cardioresistance training affords flexibility for tailoring to meet desired health and fitness outcomes and makes perceivably daunting high-intensity functional training and multimodal sports training more accessible to general, traditionally nonathletic, populations.

The Role of Retinal Carotenoids and Age on Neuroelectric Indices of Attentional Control among Early to Middle-Aged Adults.

One apparent consequence of aging appears to be loss of some aspects of cognitive control. This loss is measurable as early as mid-adulthood. Since, like many aspects of cognition, there is wide variance among individuals, it is possible that behavior, such as one's diet, could drive some of these differences. For instance, past data on older humans and non-human primates have suggested that dietary carotenoids could slow cognitive decline. In this study, we tested how early such protection might manifest by examining a sample (n = 60) of 25-45 year olds. Carotenoid status was assessed by directly measuring macular pigment optical density (MPOD) which has shown to be highly correlated with the primary carotenoid in brain, lutein. Cognitive control was measured using event-related potentials during the performance of cognitive control tasks designed to tap into different aspects of attentional (i.e., selective attention, attentional inhibition, and response inhibition) control. Our results showed that, across participants, MPOD was related to both age and the P3 component of participants' neuroelectric profile (P3 amplitude) for attentional, but not response, inhibition. Although younger adults exhibited larger P3 amplitudes than their older adult counterparts, older subjects with higher MPOD levels displayed P3 indices similar to their younger adult counterparts in amplitude. Furthermore, hierarchical regression analyses showed that age was no longer a significant predictor of P3 amplitude when MPOD was included as a predictor in the model, suggesting that MPOD may partially contribute to the relationship between age and P3 amplitude. In addition, age and MPOD were shown to have independent associations with intraindividual variability of attentional control, such that younger individuals and individuals with higher MPOD showed less intraindividual variability. These results show a relationship between retinal carotenoids and neuroelectric indices underlying cognitive control. The protective role of carotenoids within the CNS may be evident during early and middle adulthood, decades prior to the onset of older age.