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1.
Eur Eat Disord Rev ; 32(3): 450-457, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38078569

RESUMO

OBJECTIVE: This study investigated how self-reliance and denial influence the relationship between help-seeking attitudes and behaviour. METHOD: Australian university students (N = 406) completed an online survey and females with elevated eating disorder (ED) concerns and high impairment were included in the study (N = 137). Participants completed measures of help-seeking attitudes, perceived barriers, and actual help-seeking behaviour. Via moderated logistic regression, we examined self-reliance and denial as perceived barriers to help-seeking. RESULTS: Of the total sample, over 33.7% of university students reported substantial ED concerns and impairment of whom 65.0% believed they needed help. While a majority reported that help-seeking would be useful (85.4%), only a minority of participants had sought professional help for their concerns (38.7%). Self-reliance and denial were frequently endorsed barriers and moderated the relationship between help-seeking attitudes and behaviours. CONCLUSION: ED concerns are common among university students and perceived barriers play a moderating role between attitudes and help-seeking. Future prevention and early intervention programs should address students' denial, while the importance of reaching out for professional help (rather than relying on themselves) could be highlighted with peer support.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos , Aceitação pelo Paciente de Cuidados de Saúde , Feminino , Humanos , Universidades , Austrália , Estudantes
2.
Front Psychol ; 12: 628152, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33854463

RESUMO

Friendships have important influences on children's well-being and future adjustment, and interpersonal forgiveness has been suggested as a crucial means for children to maintain friendships. However, existing measures of preadolescent children's forgiveness are restricted by developmental limitations to reporting emotional responses via questionnaire and inconsistent interpretations of the term "forgive." This paper describes development and testing of concurrent and discriminant validity of a pictorial measure of children's emotional forgiveness, the Children's Forgiveness Card Set (CFCS). In Study 1, 148 Australian children aged 8-13 years (M = 10.54, SD = 1.35) responded to a hypothetical transgression in which apology was manipulated and completed the CFCS and extant measures of forgiveness and socially desirable responding. Following an exploratory factor analysis to clarify the structure of the CFCS, the CFCS correlated moderately with other forgiveness measures and did not correlate with socially desirable responding. Apology predicted CFCS responding among older children. In Study 2 an exploratory factor analysis broadly replicated the structure of the CFCS among a sample of N = 198 North American children aged 5-14 years (M = 9.39 years, SD = 1.67). We also fitted an exploratory bi-factor model to the Study 2 data which clarified which cards best measured general forgiveness, or positive or hostile aspects of responding to transgressions. Apology once again predicted the CFCS, this time regardless of age. The CFCS appears a potentially valid measure of children's emotional forgiveness. Potential applications and differences between explicit and latent forgiveness in children are discussed.

3.
Eur J Neurosci ; 49(9): 1127-1148, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30586202

RESUMO

The ability to inhibit a prepared emotional or motor action is difficult but critical to everyday functioning. It is well-established that response inhibition relies on the dopaminergic system in the basal ganglia. However, response inhibition is often measured imprecisely due to a process which slows our responses and increases subsequent inhibition success known as proactive inhibition. As the role of the dopamine system in proactive inhibition is unclear, we investigated the contribution of dopaminergic genes to proactive inhibition. We operationalised proactive inhibition as slower responses after failures to inhibit a response in a Go/No-Go paradigm and investigated its relationship to rs686/A at DRD1 (associated with increased gene expression) and rs1800497/T at DRD2 (associated with reduced D2 receptor availability). Even though our sample (N = 264) was relatively young (18-40 years), we found that proactive inhibition improves the ability to withhold erroneous responses in older participants (p = 0.002) and those with lower fluid intelligence scores (p < 0.001), indicating that proactive inhibition is likely a naturally occurring compensatory mechanism. Critically, we found that a polygenic risk score consisting of the number of rs686 A and rs1800497 T alleles predicts higher engagement of proactive inhibition (p = 0.040), even after controlling for age (p = 0.011). Furthermore, age seemed to magnify these genetic effects (p < 0.001). This suggests that the extent to which proactive inhibition is engaged depends on increased dopamine D1 and decreased D2 neurotransmission. These results provide important considerations for future work investigating disorders of the dopaminergic system.


Assuntos
Inibição Psicológica , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/genética , Adolescente , Adulto , Feminino , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Adulto Jovem
4.
Neuroimage ; 176: 179-192, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29705689

RESUMO

Learning is one of our most adaptive abilities, allowing us to adjust our expectations about future events. Aberrant learning processes may underlie disorders such as anxiety, motivating the search for the neural mechanisms that underpin learning. Animal studies have shown that the neurotransmitter GABA is required for the computation of prediction errors, the mismatches between anticipated and experienced outcomes, which drive new learning. Given that evidence from human studies is lacking, we sought to determine whether these findings extend to humans. Here, in two samples of Caucasian individuals, we investigated whether genetically determined individual differences in GABA neurotransmission predict the P3 event-related potential, an EEG component known to reflect prediction error processing. Consistent with the results of animal studies, we show that a weighted genetic risk score computed from the number of GABRB2 rs1816072 A alleles (associated with increased expression of the GABAA receptor ß2 subunit gene) and the number of ErbB4 rs7598440 T alleles (associated with increased GABA concentration) predicts optimal prediction error processing during aversive classical conditioning with both visual (Experiment 1, N = 90; p = .010) and auditory (Experiment 2; N = 92; p = .031) unconditioned stimuli. Our finding that optimal processing of aversive prediction errors is reduced in individuals genetically predisposed towards decreased GABA neurotransmission suggests a potential mechanism linking GABA and anxiety. Specifically, reduced GABA signalling via GABAA receptors could result in aberrant learning from aversive experiences and vulnerability to anxiety disorders.


Assuntos
Medo/fisiologia , Receptor ErbB-4/genética , Receptores de GABA-A/genética , Transmissão Sináptica , Adolescente , Adulto , Ansiedade/genética , Condicionamento Clássico , Eletroencefalografia , Potenciais Evocados P300 , Feminino , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , População Branca , Adulto Jovem
5.
Br J Psychol ; 109(4): 830-849, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29573264

RESUMO

The Serial Reaction Time Task (SRTT) is thought to assess implicit learning, which seems to be preserved with age. However, the reaction time (RT) measures employed on implicit-like tasks might be too unreliable to detect individual differences. We investigated whether RT-based measures mask age effects by comparing the performance of 43 younger and 35 older adults on SRTT and an explicit-like Predictive Sequence Learning Task (PSLT). RT-based measures (difference scores and a ratio) were collected for both tasks, and accuracy was additionally measured for PSLT. We also measured fluid abilities. The RT-difference scores indicated preserved SRTT and PSLT performance with age and did not correlate with fluid abilities, while ratio RT and the accuracy-based measures indicated age-related decline and correlated with fluid abilities. Therefore, RT-difference scores might mask individual differences, which compromises the interpretation of previous studies using SRTT.


Assuntos
Destreza Motora/fisiologia , Tempo de Reação/fisiologia , Aprendizagem Seriada/fisiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Individualidade , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
J Intell ; 6(1)2018 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-31162434

RESUMO

Previous experience with discrimination problems that can only be solved by learning about stimulus configurations enhances performance on new configural discriminations. Some of these effects can be explained by a shift toward increased configural processing (learning about combinations of cues rather than about individual elements), or by a tendency to generalize a learned rule to a new training set. We investigated whether fluid abilities influence the extent that previous experience with configural discriminations improves performance on subsequent discriminations. In Experiments 1 and 2 we used patterning discriminations that could be solved by applying a simple rule, whereas in Experiment 3 we used biconditional discriminations that could not be solved using a rule. Fluid abilities predicted the improvement on the second training set in all experiments, including Experiment 3 in which rule-based generalization could not explain the improvement on the second discrimination. This supports the idea that fluid abilities contribute to performance by inducing a shift toward configural processing rather than rule-based generalization. However, fluid abilities also predicted performance on a rule-based transfer test in Experiment 2. Taken together, these results suggest that fluid abilities contribute to both a flexible shift toward configural processing and to rule-based generalization.

7.
Front Psychol ; 7: 518, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27148126

RESUMO

The current study (N = 244) compared two independently developed and substantively different measures of self-confidence; a self-report measure, and a measure described as "online." Online measures are confidence-accuracy judgments made following each item on a cognitive task; in the current study, online measures were yoked to tasks of fluid and crystallized intelligence. The self-report and online measures had not previously been compared, and it was unknown if they captured the same self-confidence construct. These measures were also compared to self-efficacy and personality for the purpose of defining self-confidence as an independent construct, as well as to clarify the primary comparison. This study also aimed to replicate previous findings of a stable factor of confidence derived from online measures. An age comparison was made between a young adult sample (30 years and under) and an older adult sample (65 years and over) to determine how confidence functions across the lifespan. The primary finding was that self-report and online measures of confidence define two different but modestly correlated factors. Moreover, the self-report measures sit closer to personality, and the online measures sit closer to ability. While online measures of confidence were distinct from self-efficacy and personality, self-report measures were very closely related to the personality trait Emotional Stability. A general confidence factor-derived from online measures-was identified, and importantly was found in not just young adults but also in older adults. In terms of the age comparison, older adults had higher self-report self-confidence, and tended to be more overconfident in their judgments for online measures; however this overconfidence was more striking in the online measures attached to fluid ability than to crystallized ability.

8.
J Safety Res ; 55: 159-69, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26683559

RESUMO

INTRODUCTION: Simulator sickness is the occurrence of motion-sickness like symptoms that can occur during use of simulators and virtual reality technologies. This study investigated individual factors that contributed to simulator sickness and dropout while using a desktop driving simulator. METHOD: Eighty-eight older adult drivers (mean age 72.82±5.42years) attempted a practice drive and two test drives. Participants also completed a battery of cognitive and visual assessments, provided information on their health and driving habits, and reported their experience of simulator sickness symptoms throughout the study. RESULTS: Fifty-two participants dropped out before completing the driving tasks. A time-dependent Cox Proportional Hazards model showed that female gender (HR=2.02), prior motion sickness history (HR=2.22), and Mini-SSQ score (HR=1.55) were associated with dropout. There were no differences between dropouts and completers on any of the cognitive abilities tests. CONCLUSIONS: Older adults are a high-risk group for simulator sickness. Within this group, female gender and prior motion sickness history are related to simulator dropout. Higher reported experience of symptoms of simulator sickness increased rates of dropout. PRACTICAL APPLICATIONS: The results highlight the importance of screening and monitoring of participants in driving simulation studies. Older adults, females, and those with a prior history of motion sickness may be especially at risk.


Assuntos
Condução de Veículo/psicologia , Enjoo devido ao Movimento/epidemiologia , Enjoo devido ao Movimento/psicologia , Idoso , Idoso de 80 Anos ou mais , Simulação por Computador , Feminino , Humanos , Masculino , Modelos de Riscos Proporcionais , Fatores Sexuais , Análise de Sobrevida , Interface Usuário-Computador
9.
Neurobiol Learn Mem ; 125: 176-88, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26419600

RESUMO

Performing sequences of movements is a ubiquitous skill that involves dopamine transmission. However, it is unclear which components of the dopamine system contribute to which aspects of motor sequence learning. Here we used a genetic approach to investigate the relationship between different components of the dopamine system and specific aspects of sequence learning in humans. In particular, we investigated variations in genes that code for the catechol-O-methyltransferase (COMT) enzyme, the dopamine transporter (DAT) and dopamine D1 and D2 receptors (DRD1 and DRD2). COMT and the DAT regulate dopamine availability in the prefrontal cortex and the striatum, respectively, two key regions recruited during learning, whereas dopamine D1 and D2 receptors are thought to be involved in long-term potentiation and depression, respectively. We show that polymorphisms in the COMT, DRD1 and DRD2 genes differentially affect behavioral performance on a sequence learning task in 161 Caucasian participants. The DRD1 polymorphism predicted the ability to learn new sequences, the DRD2 polymorphism predicted the ability to perform a previously learnt sequence after performing interfering random movements, whereas the COMT polymorphism predicted the ability to switch flexibly between two sequences. We used computer simulations to explore potential mechanisms underlying these effects, which revealed that the DRD1 and DRD2 effects are possibly related to neuroplasticity. Our prediction-error algorithm estimated faster rates of connection strengthening in genotype groups with presumably higher D1 receptor densities, and faster rates of connection weakening in genotype groups with presumably higher D2 receptor densities. Consistent with current dopamine theories, these simulations suggest that D1-mediated neuroplasticity contributes to learning to select appropriate actions, whereas D2-mediated neuroplasticity is involved in learning to inhibit incorrect action plans. However, the learning algorithm did not account for the COMT effect, suggesting that prefrontal dopamine availability might affect sequence switching via other, non-learning, mechanisms. These findings provide insight into the function of the dopamine system, which is relevant to the development of treatments for disorders such as Parkinson's disease. Our results suggest that treatments targeting dopamine D1 receptors may improve learning of novel sequences, whereas those targeting dopamine D2 receptors may improve the ability to initiate previously learned sequences of movements.


Assuntos
Catecol O-Metiltransferase/genética , Aprendizagem/fisiologia , Destreza Motora/fisiologia , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/genética , Adolescente , Adulto , Algoritmos , Simulação por Computador , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Tempo de Reação/genética , Adulto Jovem
10.
Front Psychol ; 6: 1158, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26321982

RESUMO

The Serial Reaction Time Task (SRTT) was designed to measure motor sequence learning and is widely used in many fields in cognitive science and neuroscience. However, the common performance measures derived from SRTT-reaction time (RT) difference scores-may not provide valid measures of sequence learning. This is because RT-difference scores may be subject to floor effects and otherwise not sufficiently reflective of learning. A ratio RT measure might minimize floor effects. Furthermore, measures derived from predictive accuracy may provide a better assessment of sequence learning. Accordingly, we developed a Predictive Sequence Learning Task (PSLT) in which performance can be assessed via both RT and predictive accuracy. We compared performance of N = 99 adults on SRTT and PSLT in a within-subjects design and also measured fluid abilities. The RT-difference scores on both tasks were generally not related to fluid abilities, replicating previous findings. In contrast, a ratio RT measure on SRTT and PSLT and accuracy measures on PSLT were related to fluid abilities. The accuracy measures also indicated an age-related decline in performance on PSLT. The current patterns of results were thus inconsistent across different measures on the same tasks, and we demonstrate that this discrepancy is potentially due to floor effects on the RT difference scores. This may limit the potential of SRTT to measure sequence learning and we argue that PSLT accuracy measures could provide a more accurate reflection of learning ability.

11.
Br J Nutr ; 114(8): 1321-8, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26346363

RESUMO

Vitamin B12, folate and homocysteine have long been implicated in mental illness, and growing evidence suggests that they may play a role in positive mental health. Elucidation of these relationships is confounded due to the dependence of homocysteine on available levels of vitamin B12 and folate. Cross-sectional and longitudinal relationships between vitamin B12, folate, homocysteine and subjective well-being were assessed in a sample of 391 older, community-living adults without clinically diagnosed depression. Levels of vitamin B12, but not folate, influenced homocysteine levels 18 months later. Vitamin B12, folate and their interaction significantly predicted levels of positive affect (PA) 18 months later, but had no impact on the levels of negative affect or life satisfaction. Cross-sectional relationships between homocysteine and PA were completely attenuated in the longitudinal analyses, suggesting that the cross-sectional relationship is driven by the dependence of homocysteine on vitamin B12 and folate. This is the first study to offer some evidence of a causal link between levels of folate and vitamin B12 on PA in a large, non-clinical population.


Assuntos
Afeto , Ácido Fólico/sangue , Homocisteína/sangue , Vitamina B 12/sangue , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Estudos Transversais , Ingestão de Energia , Metabolismo Energético , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/sangue , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos
12.
J Pediatr ; 165(1): 170-7, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24793204

RESUMO

OBJECTIVE: To investigate the influence of a range of prenatal and postnatal factors on cognitive development in preterm and term-born adolescents. STUDY DESIGN: Woodcock-Johnson III Tests of Cognitive Abilities were used to assess general intellectual ability and 6 broad cognitive abilities in 145 young adolescents aged approximately 12.5 years and born 25-41 weeks gestational age (GA). To study potential links between neurophysiologic and cognitive outcomes, corticomotor excitability was measured using transcranial magnetic stimulation and surface electromyography. The influence of various prenatal and postnatal factors on cognitive development was investigated using relative importance regression modeling. RESULTS: Adolescents with greater GA tended to have better cognitive abilities (particularly general intellectual ability, working memory, and cognitive efficiency) and higher corticomotor excitability. Corticomotor excitability explained a higher proportion of the variance in cognitive outcome than GA. But the strongest predictors of cognitive outcome were combinations of prenatal and postnatal factors, particularly degree of social disadvantage at the time of birth, birthweight percentile, and height at assessment. CONCLUSIONS: In otherwise neurologically healthy adolescents, GA accounts for little interindividual variability in cognitive abilities. The association between corticomotor excitability and cognitive performance suggests that reduced connectivity, potentially associated with brain microstructural abnormalities, may contribute to cognitive deficits in preterm children. It remains to be determined if the effects of low GA on cognitive outcomes attenuate over childhood in favor of a concomitant increase in the relative importance of heritability, or alternatively, if cognitive development is more heavily influenced by the quality of the postnatal environment.


Assuntos
Desenvolvimento Infantil/fisiologia , Cognição/fisiologia , Recém-Nascido Prematuro/fisiologia , Adolescente , Criança , Feminino , Idade Gestacional , Humanos , Aprendizagem , Masculino
13.
Accid Anal Prev ; 70: 74-83, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24705277

RESUMO

Eighty two community dwelling older adults (52 females) aged 62-92 years (mean=75) completed a battery of cognitive and visual tests selected to assess functions relevant to driving performance. These were visual acuity, contrast sensitivity, general mental competence (Mini Mental State Examination, MMSE), processing speed (Inspection Time, IT), crowding across the visual field (Proficiency of Peripheral Vision Processing, ProPerVis) and change detection (DriverScan). These six tasks provided predictor variables for performance on the Useful Field of View test (UFOV), a well validated test of fitness to drive that includes subtests for (i) processing speed; (ii) divided attention; and (iii) selective attention. Relative importance regression analyses confirmed that UFOV is sensitive to attentional and speed processes but suggested that subtest (i) primarily reflects visual acuity and contrast sensitivity; subtest (ii) is better explained by change detection and processing speed; and subtest (iii) predominantly reflects crowding and contrast sensitivity. Unexpectedly, given no evidence of substantial cognitive decline, MMSE contributed significantly to performance on the more complex subtests (ii) and (iii).


Assuntos
Condução de Veículo/psicologia , Cognição , Percepção Visual , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Sensibilidades de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Testes Neuropsicológicos , Acuidade Visual , Campos Visuais
14.
J Nutr ; 144(3): 311-20, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24353345

RESUMO

Higher n-3 (ω-3) polyunsaturated fatty acids (PUFAs) and fish intake may help maintain cognitive function in older age. However, evidence is inconsistent; few studies have examined the relation in cognitively healthy individuals across numerous cognitive domains, and none to our knowledge have considered lifetime fish intake. We examined associations between multiple domains of cognition and erythrocyte membrane n-3 PUFA proportions and historical and contemporary fish intake in 390 normal older adults, analyzing baseline data from the Older People, Omega-3, and Cognitive Health trial. We measured n-3 PUFA in erythrocyte membranes, and we assessed historical and contemporary fish intake by food-frequency questionnaires. We assessed cognitive performance on reasoning, working memory, short-term memory, retrieval fluency, perceptual speed, simple/choice reaction time, speed of memory-scanning, reasoning speed, inhibition, and psychomotor speed. Cognitive outcomes for each construct were factor scores from confirmatory factor analysis. Multiple linear regression models controlled for a number of potential confounding factors, including age, education, sex, apolipoprotein E-ε 4 allele, physical activity, smoking, alcohol intake, socioeconomic variables, and other health-related variables. Higher erythrocyte membrane eicosapaentonoic acid proportions predicted slower perceptual and reasoning speed in females, which was attenuated once current fish intake was controlled. No other associations were present between n-3 PUFA proportions and cognitive performance. Higher current fish consumption predicted worse performance on several cognitive speed constructs. Greater fish consumption in childhood predicted slower perceptual speed and simple/choice reaction time. We found no evidence to support the hypothesis that higher proportions of long-chain n-3 fatty acids or fish intake benefits cognitive performance in normal older adults.


Assuntos
Cognição/efeitos dos fármacos , Dieta , Membrana Eritrocítica/efeitos dos fármacos , Ácidos Graxos Ômega-3/administração & dosagem , Peixes , Idoso , Idoso de 80 Anos ou mais , Alelos , Animais , Apolipoproteína E4/metabolismo , Feminino , Humanos , Modelos Lineares , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Atividade Motora , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores Socioeconômicos
15.
PLoS One ; 7(11): e50977, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23209840

RESUMO

We assessed the suitability of six applied tests of cognitive functioning to provide a single marker for dose-related alcohol intoxication. Numerous studies have demonstrated that alcohol has a deleterious effect on specific areas of cognitive processing but few have compared the effects of alcohol across a wide range of different cognitive processes. Adult participants (N = 56, 32 males, 24 females aged 18-45 years) were randomized to control or alcohol treatments within a mixed design experiment involving multiple-dosages at approximately one hour intervals (attained mean blood alcohol concentrations (BACs) of 0.00, 0.048, 0.082 and 0.10%), employing a battery of six psychometric tests; the Useful Field of View test (UFOV; processing speed together with directed attention); the Self-Ordered Pointing Task (SOPT; working memory); Inspection Time (IT; speed of processing independent from motor responding); the Traveling Salesperson Problem (TSP; strategic optimization); the Sustained Attention to Response Task (SART; vigilance, response inhibition and psychomotor function); and the Trail-Making Test (TMT; cognitive flexibility and psychomotor function). Results demonstrated that impairment is not uniform across different domains of cognitive processing and that both the size of the alcohol effect and the magnitude of effect change across different dose levels are quantitatively different for different cognitive processes. Only IT met the criteria for a marker for wide-spread application: reliable dose-related decline in a basic process as a function of rising BAC level and easy to use non-invasive task properties.


Assuntos
Cognição/efeitos dos fármacos , Etanol/farmacologia , Adolescente , Adulto , Relação Dose-Resposta a Droga , Etanol/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Adulto Jovem
16.
J Physiol ; 590(22): 5827-44, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22966161

RESUMO

The mechanisms underlying the altered neurodevelopment commonly experienced by children born preterm, but without brain lesions, remain unknown. While individuals born the earliest are at most risk, late preterm children also experience significant motor, cognitive and behavioural dysfunction from school age, and reduced income and educational attainment in adulthood. We used transcranial magnetic stimulation and functional assessments to examine corticomotor development in 151 children without cerebral palsy, aged 10-13 years and born after gestations of 25-41 completed weeks. We hypothesized that motor cortex and corticospinal development are altered in preterm children, which underpins at least some of their motor dysfunction. We report for the first time that every week of reduced gestation is associated with a reduction in corticomotor excitability that remains evident in late childhood. This reduced excitability was associated with poorer motor skill development, particularly manual dexterity. However, child adiposity, sex and socio-economic factors regarding the child's home environment soon after birth were also powerful influences on development of motor skills. Preterm birth was also associated with reduced left hemisphere lateralization, but without increasing the likelihood of being left handed per se. These corticomotor findings have implications for normal motor development, but also raise questions regarding possible longer term consequences of preterm birth on motor function.


Assuntos
Desenvolvimento Infantil/fisiologia , Potencial Evocado Motor , Córtex Motor/fisiologia , Destreza Motora/fisiologia , Adiposidade , Estudos de Casos e Controles , Feminino , Lateralidade Funcional/fisiologia , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Estudos Longitudinais , Masculino , Córtex Motor/crescimento & desenvolvimento , Tratos Piramidais/fisiologia , Fatores Socioeconômicos , Estimulação Magnética Transcraniana
17.
Nutr J ; 10: 117, 2011 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-22011460

RESUMO

BACKGROUND: Some studies have suggested an association between omega-3 long-chain polyunsaturated fatty acids (n-3 LC PUFAs) and better cognitive outcomes in older adults. To date, only two randomised, controlled trials have assessed the effect of n-3 LC PUFA supplementation on cognitive function in older cognitively healthy populations. Of these trials only one found a benefit, in the subgroup carrying the ApoE-ε4 allele. The benefits of n-3 LC PUFA supplementation on cognitive function in older normal populations thus still remain unclear. The main objective of the current study was to provide a comprehensive assessment of the potential of n-3 LC PUFAs to slow cognitive decline in normal elderly people, and included ApoE-ε4 allele carriage as a potential moderating factor. The detailed methodology of the trial is reported herein. METHODS: The study was a parallel, 18-month, randomised, double-blind, placebo-controlled intervention with assessment at baseline and repeated 6-monthly. Participants (N = 391, 53.7% female) aged 65-90 years, English-speaking and with normal cognitive function, were recruited from metropolitan Adelaide, South Australia. Participants in the intervention arm received capsules containing fish-oil at a daily dosage of 1720 mg of docosahexaenoic acid and 600 mg of eicosapentaenoic acid while the placebo arm received the equivalent amount of olive oil in their capsules. The primary outcome is rate of change in cognitive performance, as measured by latent variables for the cognitive constructs (encompassing Reasoning, Working Memory, Short-term Memory, Retrieval Fluency, Inhibition, Simple and Choice-Reaction Time, Perceptual Speed, Odd-man-out Reaction Time, Speed of Memory Scanning, and Psychomotor Speed) and assessed by latent growth curve modeling. Secondary outcomes are change in the Mini-mental State Examination, functional capacity and well-being (including health status, depression, mood, and self-report cognitive functioning), blood pressure, and biomarkers of n-3 LC PUFA status, glucose, lipid metabolism, inflammation, oxidative stress, and DNA damage. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12607000278437.


Assuntos
Envelhecimento/efeitos dos fármacos , Transtornos Cognitivos/prevenção & controle , Cognição/efeitos dos fármacos , Ácidos Graxos Ômega-3/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Apolipoproteína E4/genética , Ácidos Docosa-Hexaenoicos/administração & dosagem , Método Duplo-Cego , Ácido Eicosapentaenoico/administração & dosagem , Feminino , Óleos de Peixe/administração & dosagem , Humanos , Masculino
18.
Br J Dev Psychol ; 27(Pt 3): 669-80, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19994574

RESUMO

Inspection time (IT) measures speed of information processing without the confounding influence of motor speed. While IT has been found to relate to cognitive abilities in adults and older children, no measure of IT has been validated for use with children younger than 6 years. This study examined the validity of a new measure of IT for preschool children. N = 71 4-year-old children completed the new IT task and standardized measures of fluid ability, visuospatial ability, and speed of processing. N = 50 adults completed the same tasks and, additionally, a standard IT task. Results showed that the new IT task is a stable, reliable measure of IT in 4-year-old children. The new task had reasonable concurrent validity with the standard IT task in adults and the relationships between cognitive abilities, particularly general cognitive ability, and IT are sufficiently similar in young children and adults to suggest that the new IT task may be a useful tool for research in populations where IT was previously not measurable.


Assuntos
Atenção , Desenvolvimento Infantil , Testes de Inteligência/estatística & dados numéricos , Reconhecimento Visual de Modelos , Adolescente , Adulto , Fatores Etários , Aptidão , Pré-Escolar , Formação de Conceito , Feminino , Humanos , Masculino , Fechamento Perceptivo , Psicometria , Desempenho Psicomotor , Reprodutibilidade dos Testes , Adulto Jovem
19.
Neuropsychology ; 23(2): 158-67, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19254089

RESUMO

Psychometric measures of processing speed are strong predictors of cognitive functioning with aging; however, the neurobiological mechanisms underlying this association remain unclear. Recently, the authors reported a negative association between calculated free testosterone levels (cEFT) and processing speed in men aged between 50 and 70 years (Martin, Wittert, Burns, & McPherson, 2008). Ex-Gaussian decomposition of reaction time (RT) distributions allows for the robust estimation of skew in the distribution, which may reflect poorer attentional control. In a reanalysis of data from this previous study, the authors examined the associations between age, cEFT levels, and ex-Gaussian parameters derived from four RT tasks as predictors of cognitive functioning performance in 96 middle-to-older aged men. Results indicated that cEFT levels were significantly associated with increased skew in the RT distribution (i.e., the exponential portion) but not with the estimates derived from the Gaussian portion of the curve. Further, path analysis across the entire data set showed that this association was a strong predictor of processing speed performance. Taken together these results suggest that cEFT levels moderate cognitive functioning performance in males via attentional control processes.


Assuntos
Envelhecimento/fisiologia , Atenção/fisiologia , Tempo de Reação/fisiologia , Testosterona/sangue , Adulto , Fatores Etários , Idoso , Análise de Variância , Comportamento de Escolha/fisiologia , Humanos , Técnicas Imunoenzimáticas , Testes de Inteligência , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Distribuição Normal , Valor Preditivo dos Testes , Resolução de Problemas , Globulina de Ligação a Hormônio Sexual/metabolismo
20.
Behav Res Methods ; 40(4): 969-81, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19001388

RESUMO

Processing speed (Gs) and working memory (WM) tasks have received considerable interest as correlates of more complex cognitive performance measures. Gs and WM tasks are often repetitive and are often rigidly presented, however. The effects of Gs and WM may, therefore, be confounded with those of motivation and anxiety. In an effort to address this problem, we assessed the concurrent and predictive validity of computer-game-like tests of Gs (Space Code) and WM (Space Matrix) across two experiments. In Experiment 1, within a university sample (N = 70), Space Matrix exhibited concurrent validity as a WM measure, whereas Space Code appeared to be a mixed-ability measure. In Experiment 2, Space Matrix exhibited concurrent validity as well as predictive validity (as a predictor of school grades) within a school-aged sample (N = 94), but the results for Space Code were less encouraging. Relationships between computer-game-like tests and gender, handedness, and computer-game experience are also discussed.


Assuntos
Computadores , Memória de Curto Prazo , Tempo de Reação , Jogos de Vídeo , Adolescente , Adulto , Criança , Análise Fatorial , Feminino , Humanos , Masculino , Psicologia/métodos , Reprodutibilidade dos Testes , Percepção Visual
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