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1.
J Nutr ; 149(12): 2255-2264, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504690

RESUMO

BACKGROUND: Hydration effects on cognition remain understudied in children. This is concerning since a large proportion of US children exhibit insufficient hydration. OBJECTIVE: This study investigated the effects of water intake on urinary markers of hydration and cognition among preadolescents. METHODS: A 3-intervention crossover design was used among 9- to 11-y-olds [n = 75 (43 males, 32 females); 58.2 ± 28.5 BMI percentile]. Participants maintained their water intake [ad libitum (AL)] or consumed high (2.5 L/d) or low (0.5 L/d) water for 4 d. The primary outcomes were performance on cognitive tasks requiring inhibition, working memory, and cognitive flexibility assessed using a modified flanker, go/no-go, and color-shape switch tasks, respectively. Secondary outcomes included urine hydration indices [i.e., color, urine specific gravity (USG), osmolality] assessed using 24-h urine collected during day 4 of each intervention. Repeated-measures ANOVAs were used to assess intervention effects. RESULTS: There was a significant difference in hydration across all 3 interventions. Urine color during the low intervention [median (IQR): 6 (2)] was greater than during AL [5 (2)], and both were greater than during the high intervention [18 (0)] (all P ≤ 0.01). Similarly, osmolality [low (mean ± SD): 912 ± 199 mOsmol/kg, AL: 790 ± 257.0 mOsmol/kg, high: 260 ± 115 mOsmol/kg] and USG [low (mean ± SD): 1.023 ± 0.005, AL: 1.020 ± 0.007, high: 1.005 ± 0.004] during the low intervention were greater during AL, and both were greater than during the high intervention (all P ≤ 0.01). USG and osmolality AL values were related to switch task measures (ß: 0.21 to -0.31, P < 0.05). Benefits of the high intervention were observed during the switch task, whereby participants exhibited 34% lower working memory cost relative to the low intervention. No significant changes in cognition were observed for the flanker and go/no-go tasks. CONCLUSIONS: The water intervention improved urinary markers of hydration and had selective benefits during task switching. Furthermore, children's cognitive flexibility selectively benefits from greater habitual hydration and water intake. This study is registered at clinicaltrials.gov as NCT02816450.

2.
J Sport Health Sci ; 8(4): 301-314, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31333883

RESUMO

Background: Structured vigorous physical activity (VPA) can improve cognitive control in children, but studies relating daily physical activity (PA) to cognitive control have yielded conflicting findings. While objectively measured daily PA summarizes all occurrences of PA within a registered period, a minimum duration of continuous PA is required for registration of a PA bout. Because brief bouts of high-intensity PA can account for a large proportion of children's daily activity-related energy expenditure, this study assessed whether daily and bouted VPA were selectively related to cognitive control in preadolescents relative to other PA intensities. Methods: A total of 75 children between the ages of 8 and 10 years (49% girls) wore an ActiGraph wGT3X+ on the hip for 7 days. The acceleration signal from the vertical axis was summarized over 1 s, 5 s, and 15 s epochs. Daily and bouted moderate PA, moderate-to-vigorous PA, and VPA were measured. PA bouts were expressed as the frequency and time spent in 2 different continuous PA bouts, one lasting ≥10 s and the other lasting ≥30 s at a given intensity. Inhibitory control was assessed using behavioral responses to a modified flanker task (mean reaction time (RTmean) and accuracy). Attentional resource allocation and cognitive processing speed were measured using the amplitude and latency of the P3 component of event-related brain potentials, respectively. Associations between PA, behavioral indices of inhibitory control, P3 amplitude, and latency were assessed using hierarchical regression models. Results: Daily VPA was not related to RTmean or accuracy on either congruent or incongruent trials. In contrast, more time spent in VPA bouts lasting ≥30 s predicted shorter P3 latency across epochs and flanker congruencies (all ß ≤ -0.24, all p ≤ 0.04). The associations between shorter P3 latency and the time spent in moderate-to-vigorous PA bouts lasting ≥30 s were less consistent and largely limited to congruent trials (congruent: ß (-0.31, -0.34)). No significant associations were observed upon correction for false discovery rate. Conclusion: The pattern of uncorrected associations aligns with the dose-response literature and suggests that brief VPA bouts may yield the greatest benefits to cognitive processing speed in preadolescents. Future studies using measures of brain structure and function are needed to understand the mechanisms linking bouted VPA to neurocognitive function during childhood.

3.
Ann Nutr Metab ; 74 Suppl 3: 19-24, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31203295

RESUMO

The effects of optimal and insufficient hydration on human health have received increasing investigation in recent years. Specifically, water is an essential nutrient for human health, and the importance of hydration on cognition has continued to attract research interest over the last decade. Despite this focus, children remain a relatively understudied population relative to the effects of hydration on cognition. Of those studies investigating children, findings have been inconsistent, resulting from utilizing a wide variety of cognitive domains and cognitive assessments, as well as varied hydration protocols. Here, our aim is to create a primer for assessing cognition during hydration research in children. Specifically, we review the definition of cognition and the domains of which it is composed, how cognition has been measured in both field- and laboratory-based assessments, results from neuroimaging methods, and the relationship between hydration and academic achievement in children. Lastly, future research considerations are discussed.

4.
Front Psychol ; 9: 1298, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30158882

RESUMO

Previous research has found positive associations between cognitive control and aerobic fitness in preadolescents and adults; however, fewer studies have investigated these associations in adolescents. Adolescence is of particular interest due to continued maturation of the prefrontal cortex; an area that subserves cognitive control. This study investigated the associations of aerobic fitness and cognitive control in adolescents. An assessment of aerobic fitness (Andersen intermittent running test) and two tests of cognitive control were collected to investigate these associations. Participants completed a test of inhibitory control (flanker task) and a test of cognitive flexibility (switch task). Along with traditional measures of reaction time (RT) and accuracy, diffusion modeling was utilized to combine these measures to calculate latent variables (i.e., drift rate, boundary separation, and nondecision time). Associations between cognitive measures and fitness were assessed with linear regressions while controlling for potential confounding factors. Higher fitness was associated with shorter reaction time and higher accuracy in the flanker task, indicating better inhibitory control performance. In addition, greater aerobic fitness was associated with greater quality of information uptake in the flanker task, as indicated by drift rate. In the switch task, higher aerobic fitness was associated with greater accuracy and longer switch RT indicating a speed-accuracy tradeoff. Results from the switch task diffusion modeling supported this conclusion as indicated by greater fitness associated with greater boundary separation, or response conservativeness. Further, greater drift rate in the switch task was associated with greater fitness. These findings corroborate growing evidence indicating the importance of aerobic fitness for inhibitory control and cognitive flexibility. This study extends the literature by demonstrating these effects in a large sample of adolescents with a computational model of the mechanisms that underlie cognition.

5.
PLoS One ; 13(6): e0199281, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29912925

RESUMO

The main objective of this study was to investigate the associations between waist circumference, metabolic risk factors, and executive function in adolescents. METHODS: The study was cross-sectional and included 558 adolescents (mean age 14.2 years). Anthropometrics and systolic blood pressure (sysBP) were measured and fasting blood samples were analyzed for metabolic risk factors. A metabolic risk factor cluster score (MetS-cluster score) was computed from the sum of standardized sysBP, triglycerides (TG), inverse high-density lipid cholesterol (HDLc) and insulin resistance (homeostasis model assessment). Cognitive control was measured with a modified flanker task. RESULTS: Regression analyses indicated that after controlling for demographic variables, HDLc exhibited a negative and TG a positive association with flanker reaction time (RT). Waist circumference did not demonstrate a statistically significant total association with the cognitive outcomes. In structural equation modeling, waist circumference displayed an indirect positive association with incongruent RT through a higher MetS-cluster score and through lower HDLc. The only statistically significant direct association between waist circumference and the cognitive outcomes was for incongruent RT in the model including HDLc as mediator. CONCLUSIONS: These findings are consonant with the previous literature reporting an adverse association between certain metabolic risk factors and cognitive control. Accordingly, these results suggest specificity between metabolic risk factors and cognitive control outcomes. Further, results of the present study, although cross-sectional, provide new evidence that specific metabolic risk factors may mediate an indirect association between adiposity and cognitive control in adolescents, even though a direct association between these variables was not observed. However, taking the cross-sectional study design into consideration, these results should be interpreted with caution and future longitudinal or experimental studies should verify the findings of this study.


Assuntos
Transtornos Cognitivos/sangue , Resistência à Insulina/fisiologia , Doenças Metabólicas/sangue , Tempo de Reação/fisiologia , Adolescente , Antropometria , Pressão Sanguínea , HDL-Colesterol/sangue , Transtornos Cognitivos/fisiopatologia , Feminino , Humanos , Masculino , Doenças Metabólicas/fisiopatologia , Análise de Regressão , Fatores de Risco , Triglicerídeos/sangue , Circunferência da Cintura/fisiologia
6.
Psychophysiology ; 55(3)2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28976540

RESUMO

The present study investigated the effect of a 9-month physical activity (PA) intervention on children's cardiorespiratory fitness levels and neuroelectric indices of conflict monitoring (i.e., error-related negativity, ERN). Four hundred twenty-eight preadolescent children (8-9 years old) were randomized into a PA intervention or wait-list control group, and completed a fitness and cognitive control assessment (i.e., modified flanker task) at pre- and posttest. Following exclusion criterion, 308 children were included in the analyses (PA intervention: n = 139; wait-list control: n = 169). Children in the intervention displayed greater improvements in fitness and response accuracy, which were accompanied by stability of ERN amplitude from pre- to posttest. In contrast, the control group revealed increased ERN amplitude at posttest compared to pretest, despite no change in fitness or task performance. These findings demonstrate the efficacy of daily PA for promoting children's fitness and underlying neural processes associated with effective conflict monitoring. Such findings have significant implications for promoting organized PA programs intended to foster overall physical and brain health in school age children.


Assuntos
Encéfalo/fisiologia , Conflito Psicológico , Exercício Físico , Desempenho Psicomotor , Criança , Potenciais Evocados , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Aptidão Física , Tempo de Reação
7.
Psychophysiology ; 54(9): 1335-1345, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28480961

RESUMO

The purpose of this study was to investigate the effects of a single bout of high-intensity interval training (HIIT) and continuous aerobic exercise (CAE) on inhibitory control. The P3 component of the stimulus-locked ERP was collected in 64 young adults during a modified flanker task following 20 min of seated rest, 20 min of CAE, and 9 min of HIIT on separate days in counterbalanced order. Participants exhibited shorter overall reaction time following CAE and HIIT compared to seated rest. Response accuracy improved following HIIT in the task condition requiring greater inhibitory control compared to seated rest and CAE. P3 amplitude was larger following CAE compared to seated rest and HIIT. Decreased P3 amplitude and latency were observed following HIIT compared to seated rest. The current results replicated previous findings indicating the beneficial effect of acute CAE on behavioral and neuroelectric indices of inhibitory control. With a smaller duration and volume of exercise, a single bout of HIIT resulted in additional improvements in inhibitory control, paralleled by a smaller and more efficient P3 component. In sum, the current study demonstrated that CAE and HIIT differentially facilitate inhibitory control and its underlying neuroelectric activation, and that HIIT may be a time-efficient approach for enhancing cognitive health.


Assuntos
Encéfalo/fisiologia , Cognição/fisiologia , Potenciais Evocados/fisiologia , Exercício Físico/psicologia , Treinamento Intervalado de Alta Intensidade/psicologia , Inibição Psicológica , Caminhada/psicologia , Adolescente , Exercício Físico/fisiologia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Consumo de Oxigênio/fisiologia , Tempo de Reação/fisiologia , Caminhada/fisiologia , Adulto Jovem
8.
Brain Cogn ; 113: 85-92, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28160688

RESUMO

Aerobic fitness has previously been related to cognitive control in preadolescents; however, these investigations have generally relied on global measures of performance. Thus, we have little understanding of how aerobic fitness may relate to trial-by-trial modulations in cognitive control. This study utilized congruency sequence effects (CSEs), which characterize how behavior on the current trial is influenced by the previous trial, to investigate the relation of aerobic fitness on varying levels of cognitive control. One hundred eighty-seven children completed tests of aerobic fitness and a flanker task. Regressions were performed to determine relationships between CSE sequences and aerobic fitness while controlling for other potential confounding factors (e.g., age, sex, IQ). Lower-fit children were less able to modulate cognitive control during sequences requiring relatively less cognitive control. Additionally, lower-fit children were less able to adjust for variable levels of cognitive control during relatively more difficult sequences. Lastly, lower-fit children had longer reaction times (RTs) for all sequences in the condition requiring greater amounts of cognitive control. These findings corroborate the importance of aerobic fitness for cognitive control in school-aged children, and extend the literature by demonstrating a relationship between fitness and trial-by-trial modulations in control demands.


Assuntos
Cognição/fisiologia , Aptidão Física/psicologia , Desempenho Psicomotor/fisiologia , Criança , Exercício Físico/psicologia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia
9.
J Mot Behav ; 49(2): 150-162, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27715503

RESUMO

The authors used a conditional accuracy function (CAF) method to compute the mean accuracy of multiple reaction time ranges, to investigate the association between aerobic fitness and the utilization of cognitive control strategy during preadolescence. Thirty-eight higher- and lower-fit children were grouped according to their cardiorespiratory capacity (VO2max) and completed a modified flanker task. Seventeen young adults were recruited as a reference group of maturation. The results showed that higher-fit children exhibited an adult-like performance pattern, and demonstrated increased overall response accuracy compared to lower-fit children, with a disproportionally larger increase in individual responses when the time allowed for discriminative processing was constrained. These findings suggest that aerobic fitness is associated with enhanced cognitive control and development of a more proactive control strategy during flanker task in preadolescent children.


Assuntos
Cognição/fisiologia , Exercício Físico/psicologia , Aptidão Física/psicologia , Envelhecimento/fisiologia , Criança , Feminino , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Aptidão Física/fisiologia , Tempo de Reação/fisiologia , Adulto Jovem
10.
Med Sci Sports Exerc ; 49(3): 500-508, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27776002

RESUMO

PURPOSE: This study investigated the relationship between aerobic and muscular fitness with working memory and academic achievement in preadolescent children. METHODS: Seventy-nine 9- to 11-yr-old children completed an aerobic fitness assessment using a graded exercise test; a muscular fitness assessment consisting of upper body, lower body, and core exercises; a serial n-back task to assess working memory; and an academic achievement test of mathematics and reading. RESULTS: Hierarchical regression analyses indicated that after controlling for demographic variables (age, sex, grade, IQ, socioeconomic status), aerobic fitness was associated with greater response accuracy and d' in the 2-back condition and increased mathematic performance in algebraic functions. Muscular fitness was associated with increased response accuracy and d', and longer reaction time in the 2-back condition. Further, the associations of muscular fitness with response accuracy and d' in the 2-back condition were independent of aerobic fitness. CONCLUSION: The current findings suggest the differential relationships between the aerobic and the muscular aspects of physical fitness with working memory and academic achievement. With the majority of research focusing on childhood health benefits of aerobic fitness, this study suggests the importance of muscular fitness to cognitive health during preadolescence.


Assuntos
Logro , Memória de Curto Prazo/fisiologia , Músculo Esquelético/fisiologia , Aptidão Física/fisiologia , Aptidão Física/psicologia , Criança , Cognição/fisiologia , Feminino , Humanos , Masculino , Tempo de Reação , Análise e Desempenho de Tarefas
11.
J Pediatr Rehabil Med ; 8(4): 297-308, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26684070

RESUMO

PURPOSE: The neural substrate of post-concussive symptoms following the initial injury period after mild traumatic brain injury (mTBI) in pediatric populations remains poorly elucidated. This study examined neuropsychological, behavioral, and brain functioning in adolescents post-mTBI to assess whether persistent differences were detectable up to a year post-injury. METHODS: Nineteen adolescents on average 7.5 months post-mTBI completed neuropsychological testing and an fMRI auditory-verbal N-back working memory task. Parents completed behavioral ratings. The comparison group included 19 healthy controls matched to the mTBI group for demographic variables and N-back task performance. RESULTS: There were no between-group differences for cognition or behavior ratings. The expected decreased accuracy and increased reaction time as N-back task difficulty increased were apparent. The mTBI group showed significantly greater brain activation than controls during the most difficult working memory load condition. CONCLUSION: Greater working memory task-related activation was found in adolescents up to one year post-mTBI relative to controls, potentially indicating compensatory activation to support normal task performance. Differences in brain activation in the mTBI group so long after injury may indicate residual alterations in brain function much later than would be expected based on the typical pattern of symptom recovery, which could have important clinical implications.


Assuntos
Lesões Encefálicas/fisiopatologia , Encéfalo/fisiopatologia , Memória de Curto Prazo/fisiologia , Adolescente , Criança , Estudos Transversais , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino
12.
Dev Neuropsychol ; 40(1): 40-4, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25649779

RESUMO

We evaluated cerebral blood flow (CBF) in chronic pediatric mild traumatic brain injury (mTBI) using arterial spin labeling (ASL) magnetic resonance imaging perfusion. mTBI patients showed lower CBF than controls in bilateral frontotemporal regions, with no between-group cognitive differences. Findings suggest ASL may be useful to assess functional abnormalities in pediatric mTBI.


Assuntos
Lesões Encefálicas/fisiopatologia , Circulação Cerebrovascular/fisiologia , Transtornos Cognitivos/fisiopatologia , Angiografia por Ressonância Magnética/métodos , Marcadores de Spin , Adolescente , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Criança , Doença Crônica , Transtornos Cognitivos/etiologia , Feminino , Humanos , Masculino
13.
PLoS One ; 9(5): e97964, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24848559

RESUMO

Theoretical and empirical evidence suggests that impaired time perception and the neural circuitry underlying internal timing mechanisms may contribute to severe psychiatric disorders, including psychotic and mood disorders. The degree to which alterations in temporal perceptions reflect deficits that exist across psychosis-related phenotypes and the extent to which mood symptoms contribute to these deficits is currently unknown. In addition, compared to schizophrenia, where timing deficits have been more extensively investigated, sub-second timing has been studied relatively infrequently in bipolar disorder. The present study compared sub-second duration estimates of schizophrenia (SZ), schizoaffective disorder (SA), non-psychotic bipolar disorder (BDNP), bipolar disorder with psychotic features (BDP), and healthy non-psychiatric controls (HC) on a well-established time perception task using sub-second durations. Participants included 66 SZ, 37 BDNP, 34 BDP, 31 SA, and 73 HC who participated in a temporal bisection task that required temporal judgements about auditory durations ranging from 300 to 600 milliseconds. Timing variability was significantly higher in SZ, BDP, and BDNP groups compared to healthy controls. The bisection point did not differ across groups. These findings suggest that both psychotic and mood symptoms may be associated with disruptions in internal timing mechanisms. Yet unexpected findings emerged. Specifically, the BDNP group had significantly increased variability compared to controls, but the SA group did not. In addition, these deficits appeared to exist independent of current symptom status. The absence of between group differences in bisection point suggests that increased variability in the SZ and bipolar disorder groups are due to alterations in perceptual timing in the sub-second range, possibly mediated by the cerebellum, rather than cognitive deficits.


Assuntos
Transtorno Bipolar/fisiopatologia , Esquizofrenia/fisiopatologia , Percepção do Tempo , Transtorno Bipolar/complicações , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/psicologia , Estudos de Casos e Controles , Feminino , Humanos , Inteligência , Masculino , Transtornos Psicóticos/complicações , Psicotrópicos/uso terapêutico , Esquizofrenia/complicações , Esquizofrenia/tratamento farmacológico
14.
Schizophr Bull ; 40(5): 1001-10, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23962891

RESUMO

Consistent with reports of cerebellar structural, functional, and neurochemical anomalies in schizophrenia, robust cerebellar-dependent delay eyeblink conditioning (dEBC) deficits have been observed in the disorder. Impaired dEBC is also present in schizotypal personality disorder, an intermediate phenotype of schizophrenia. The present work sought to determine whether dEBC deficits exist in nonpsychotic first-degree relatives of individuals with schizophrenia. A single-cue tone dEBC paradigm consisting of 10 blocks with 10 trials each (9 paired and 1 unpaired trials) was used to examine the functional integrity of cerebellar circuitry in schizophrenia participants, individuals with a first-degree relative diagnosed with schizophrenia, and healthy controls with no first-degree relatives diagnosed with schizophrenia. The conditioned stimulus (a 400ms tone) coterminated with the unconditioned stimulus (a 50ms air puff to the left eye) on paired trials. One relative and 2 healthy controls were removed from further analysis due to declining conditioned response rates, leaving 18 schizophrenia participants, 17 first-degree relatives, and 16 healthy controls. Electromyographic data were subsequently analyzed using growth curve models in hierarchical linear regression. Acquisition of dEBC conditioned responses was significantly impaired in schizophrenia and first-degree relative groups compared with controls. This finding that cerebellar-mediated associative learning deficits are present in first-degree relatives of individuals with schizophrenia provides evidence that dEBC abnormalities in schizophrenia may not be due to medication or course of illness effects. Instead, the present results are consistent with models of schizophrenia positing cerebellar-cortical circuit abnormalities and suggest that cerebellar abnormalities represent a risk marker for the disorder.


Assuntos
Aprendizagem por Associação/fisiologia , Piscadela/fisiologia , Cerebelo/fisiopatologia , Condicionamento Palpebral/fisiologia , Núcleo Familiar , Transtornos Psicóticos/fisiopatologia , Esquizofrenia/fisiopatologia , Adulto , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Psicóticos/genética , Esquizofrenia/genética
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