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1.
Dev Sci ; : e13561, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39162657

RESUMEN

Intra-individual response time variability (IIRTV) during cognitive performance is increasingly recognized as an important indicator of attentional control (AC) and related brain region function. However, what determinants contribute to preschoolers' IIRTV received little attention. The present study explored the interaction of dopaminergic polygenic composite score (DPCS) and the parent-child relationship in relation to preschoolers' IIRTV. In the initial sample, 452 preschoolers (M age = 5.17, SD = 0.92) participated in the study. The modified Flanker task was used to evaluate children's IIRTV and their parents were requested to complete the Parent-Child Relationship Scale to assess the parent-child relationship (closeness/conflict). DNA data were extracted from children's saliva samples, and a DPCS was created by the number of COMT, DAT1, and DRD2 alleles associated with lower dopamine levels. Results showed that DPCS significantly interacted with the parent-child closeness to impact preschoolers' IIRTV. Specifically, preschoolers with higher DPCS exhibited lower IIRTV under higher levels of the parent-child closeness, and greater IIRTV under lower levels of the parent-child closeness compared to those with lower DPCS, which supported the differential susceptibility theory (DST). A direct replication attempt with 280 preschoolers (M age = 4.80, SD = 0.86) was conducted to investigate whether the results were in accordance with our exploratory outcomes. The interactive effect of DPCS and the parent-child closeness on IIRTV was confirmed. Additionally, the significant interactive effect of DPCS and the parent-child conflict on IIRTV was found in the replication study. The findings indicate that preschoolers' IIRTV, as an indicator of AC and related brain region function, is influenced by the interactions of dopaminergic genotypes and the parent-child relationship. RESEARCH HIGHLIGHTS: We investigated the Gene × Environment mechanism to underline the intra-individual response time variability as an indicator of attentional control (AC) in Chinese preschoolers. Dopaminergic polygenic composite score (COMT, DAT1, and DRD2) interacted with the parent-child relationship to predict preschoolers' intra-individual reaction time variability. A direct replication attempt has been conducted, and the results were in accordance with our exploratory outcomes, which increased the credibility of the present findings. The findings highlight the importance of considering precursors, including polygenic and environmental factors, which contribute to the development of early cognitive performance such as AC.

2.
Neurosci Biobehav Rev ; 162: 105703, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38718988

RESUMEN

Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with executive function deficits that are improved with medications. However, meta-analyses of stimulant effects on cognition have mostly tested single-dose effects, and there is no meta-analysis of non-stimulant effects. This systematic review and meta-analysis tested the clinically more relevant longer-term effects of Methylphenidate (20 studies; minimum 1 week) and Atomoxetine (8 studies; minimum 3 weeks) on reaction time, attention, inhibition, and working memory, searching papers on PubMed, Embase, Ovid MEDLINE, and PsycINFO. The meta-analysis of 18 studies in 1667 subjects showed that methylphenidate was superior to placebo in all cognitive domains with small to medium effect sizes (Hedges g of 0.34-0.59). The meta-analysis of atomoxetine included 7 studies in 829 subjects and showed no effects in working memory, but superior effects in the other domains with medium to large effect sizes (Hedge's g of 0.36-0.64). Meta-regression analysis showed no drug differences on cognitive effects. The meta-analyses show for the first time that chronic Methylphenidate and Atomoxetine have comparable effects of improving executive functions in people with ADHD.


Asunto(s)
Clorhidrato de Atomoxetina , Trastorno por Déficit de Atención con Hiperactividad , Estimulantes del Sistema Nervioso Central , Función Ejecutiva , Metilfenidato , Humanos , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Función Ejecutiva/efectos de los fármacos , Función Ejecutiva/fisiología , Estimulantes del Sistema Nervioso Central/farmacología , Estimulantes del Sistema Nervioso Central/administración & dosificación , Metilfenidato/farmacología , Metilfenidato/administración & dosificación , Clorhidrato de Atomoxetina/farmacología , Clorhidrato de Atomoxetina/administración & dosificación , Memoria a Corto Plazo/efectos de los fármacos , Memoria a Corto Plazo/fisiología
3.
J Atten Disord ; 28(9): 1275-1288, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38491856

RESUMEN

OBJECTIVE: To determine whether girls and boys with ADHD show distinct impairments in components of cognitive control across multiple tasks (go/no-go, stop signal, and flanker) and performance metrics (response speed, variability, and errors). METHOD: A total of 300 children, ages 8 to 12 years with ADHD (n = 210, 58 girls) or typically developing (TD; n = 99, 37 girls), completed all tasks. Traditional response measures (e.g., mean and standard deviation of reaction time, inhibition errors, and stop signal reaction time) and ex-Gaussian modeling of reaction times (mu, sigma, and tau) were analyzed. RESULTS: Girls showed intact response inhibition in the context of slower response speed, while boys made more inhibition errors and did not slow their response speed. Both girls and boys with ADHD showed higher response variability and poorer interference control than TD children. CONCLUSION: Girls and boys with ADHD show distinct impairments in cognitive control that may be important for understanding the pathophysiology of ADHD.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Inhibición Psicológica , Tiempo de Reacción , Humanos , Trastorno por Déficit de Atención con Hiperactividad/psicología , Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Niño , Masculino , Femenino , Tiempo de Reacción/fisiología , Factores Sexuales , Cognición/fisiología , Pruebas Neuropsicológicas , Función Ejecutiva/fisiología , Desempeño Psicomotor/fisiología
4.
Aggress Behav ; 50(1): e22110, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37624086

RESUMEN

Deficits in attentional control or inhibitory control are distinct features of childhood aggressive behaviors. Lower attentional control or inhibitory control is considered to predict more aggressive behaviors, while few studies have documented the possible predictive effects of aggressive behaviors on attentional control or inhibitory control. The present study examined the bidirectional relations between aggressive behaviors and both inhibitory control and attentional control in 169 Chinese primary school children (75 girls, Mage = 7.15, SDage = 0.33), annually for 3 years starting at age 7. The No-go accuracy on a Go/No-go task was used as the index of inhibitory control, and the intraindividual reaction time variability (IIRTV) of correct Go trials indicated attentional control. The aggressive behaviors subscale of the child behavior checklist-Chinese version was used to assess the children's aggressive behaviors. The results demonstrated a significant and stable predictive effect of previous aggressive behaviors on subsequent attentional control, with more aggressive behaviors predicting greater IIRTV at both the between-child and within-child levels. No significant effects of inhibitory control or attentional control on aggressive behaviors or sex-specific patterns were found. The findings suggest the negative impact of childhood aggressive behaviors on attentional control and underscore the importance of early prevention and intervention for childhood aggressive behaviors.


Asunto(s)
Agresión , Atención , Masculino , Femenino , Humanos , Niño , Lactante , Tiempo de Reacción
5.
Atten Percept Psychophys ; 86(1): 109-145, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38012476

RESUMEN

The ability to sustain attention is often measured with either objective performance indicators, like within-person RT variability, or subjective self-reports, like mind wandering propensity. A more construct valid approach, however, may be to assess the covariation in these performance and self-report measures, given that each of these is influenced by different sources of measurement error. If the correlation between performance-variability and self-report measures reflects the sustained attention construct, then task manipulations aimed at reducing the sustained attention demands of tasks should reduce the correlation between them (in addition to reducing mean levels of variability and mind wandering). The current study investigated this claim with a combined experimental-correlation approach. In two experiments (Ns ~ 1,500 each), participants completed tasks that either maximized or minimized the demand for sustained attention. Our demand manipulations successfully reduced the mean levels of sustained attention failures in both the objective and subjective measures, in both experiments. In neither experiment, however, did the covariation between these measures change as a function of the sustained attention demands of the tasks. We can therefore claim only minimal support for the construct validity of our measurement approach to sustained attention.


Asunto(s)
Atención , Humanos , Autoinforme
6.
Exp Brain Res ; 241(11-12): 2693-2703, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37812230

RESUMEN

Previous work has shown that exposure to auditory white noise (WN) can improve cognitive performance in children with ADHD, but it is unknown whether this improvement generalizes to other sensory modalities. To address this knowledge gap, we tested the effect of Stochastic Vestibular Stimulation (SVS) on cognitive performance and reaction time (RT) variability in two groups: children with ADHD and typically developing children (TDC). Children with ADHD (N=42) and TDC (N=28) performed three cognitive tasks (Spanboard, Word Recall and N-back tasks) at two different occasions, with and without exposure to SVS, in a double blinded design. The results showed no main effects of SVS on neither performance nor RT variability for children in any of the groups, and no interactions between SVS and group. Based on these results we conclude that, using our stimulation protocol, the positive effects of WN exposure on cognition in children with ADHD do not generalize to Stochastic Vestibular Stimulation.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Humanos , Niño , Trastorno por Déficit de Atención con Hiperactividad/terapia , Tiempo de Reacción/fisiología , Cognición/fisiología , Recuerdo Mental
7.
Front Psychol ; 14: 1096266, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37139000

RESUMEN

Addressing comorbidities contributing to cognitive impairment in people living with HIV (PLWH) remains imperative. Prior studies utilizing reaction time intra-individual variability (RT-IIV), a robust behavioral marker of cognitive dysfunction, demonstrate increased cognitive impairment in adults living with HIV who have high early life stress (ELS) exposure relative to those with low-ELS exposure. Yet, it is unknown whether RT-IIV elevations are due to high-ELS alone or both HIV-status and high-ELS. In the current study, we explore the potential additive effects of HIV and high-ELS exposure on RT-IIV to better characterize the independent and combined effects of these factors on RT-IIV among PLWH. We assessed 59 PLWH and 69 HIV-negative healthy control (HC) participants with either low or high ELS on RT-IIV during a working memory task (1-back). We observed a significant interaction between HIV status and ELS exposure on RT-IIV, PLWH who had experienced high ELS demonstrating RT-IIV elevations relative to all other groups. In addition, RT-IIV was significantly associated with ELS exposure in PLWH, but not in the HC group. We also observed associations between RT-IIV and measures of HIV-disease severity (plasma HIV viral load, nadir CD4) among PLWH. Taken as a whole, these findings provide novel evidence of the combined effects of HIV and high-ELS exposure on RT-IIV, and thus suggest HIV-related and ELS-related neural abnormalities may act in an additive or synergistic manner to affect cognition. Such data warrant further investigation into the neurobiological mechanisms associated with HIV and high-ELS exposure that contribute to increased neurocognitive dysfunction among PLWH.

8.
Artículo en Inglés | MEDLINE | ID: mdl-37027069

RESUMEN

Family functioning including family adaptability and family cohesion, and intraindividual reaction time variability (IIV) which serves as an index of attentional control has been found to relate to children's externalizing problems. However, it remains unknown whether family functioning interacts with children's IIV to predict their externalizing problems based on the diathesis-stress model. The present study examined this concern. Participants included 168 (Mage = 7.35 years, SD = 0.48; 48% boys) and 155 (Mage = 8.32 years, SD = 0.45; 49% boys) children at the first (T1) and second (after one year, T2) measurements, respectively. At T1, a flanker task was used to assess children's IIV. Mothers reported family functioning using the Chinese version of the Family Adaptability and Cohesion Scales, and children's externalizing problems using the Chinese version of the Child Behavior Checklist. At T2, mothers reported children's externalizing problems again. Results indicated that family functioning negatively and IIV positively correlated with children's externalizing problems. Furthermore, family functioning interacted with children's IIV to predict their externalizing problems concurrently and longitudinally. Specifically, low family functioning combined with greater IIV predicted prospective externalizing problems. Findings suggested that better attentional control (indexed by lower IIV) may buffer the negative effect of poor family functioning.

9.
Comput Brain Behav ; : 1-38, 2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36618326

RESUMEN

Human performance shows substantial endogenous variability over time, and this variability is a robust marker of individual differences. Of growing interest to psychologists is the realisation that variability is not fully random, but often exhibits temporal dependencies. However, their measurement and interpretation come with several controversies. Furthermore, their potential benefit for studying individual differences in healthy and clinical populations remains unclear. Here, we gather new and archival datasets featuring 11 sensorimotor and cognitive tasks across 526 participants, to examine individual differences in temporal structures. We first investigate intra-individual repeatability of the most common measures of temporal structures - to test their potential for capturing stable individual differences. Secondly, we examine inter-individual differences in these measures using: (1) task performance assessed from the same data, (2) meta-cognitive ratings of on-taskness from thought probes occasionally presented throughout the task, and (3) self-assessed attention-deficit related traits. Across all datasets, autocorrelation at lag 1 and Power Spectra Density slope showed high intra-individual repeatability across sessions and correlated with task performance. The Detrended Fluctuation Analysis slope showed the same pattern, but less reliably. The long-term component (d) of the ARFIMA(1,d,1) model showed poor repeatability and no correlation to performance. Overall, these measures failed to show external validity when correlated with either mean subjective attentional state or self-assessed traits between participants. Thus, some measures of serial dependencies may be stable individual traits, but their usefulness in capturing individual differences in other constructs typically associated with variability in performance seems limited. We conclude with comprehensive recommendations for researchers. Supplementary Information: The online version contains supplementary material available at 10.1007/s42113-022-00162-1.

10.
Res Child Adolesc Psychopathol ; 51(1): 17-31, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36006496

RESUMEN

Attention-deficit/hyperactivity (ADHD) and autism spectrum (ASD) disorders are commonly co-occurring conditions characterized by neurocognitive impairments. Few studies have directly compared neurocognitive profiles in ADHD and ASD and fewer still have controlled for comorbidity of ADHD and ASD. All direct comparisons have been in clinic samples, leaving the question of generalizability of results unaddressed. We compared neurocognitive performance in clinically ascertained ASD (n = 261) and ADHD (n = 423) cases and controls (n = 162), 6.0-17.9 years of age. We also compared ASD (n = 190) and ADHD (n = 926) cases ascertained in the community with controls (n = 14,842) of similar age. Using the stop-signal task (SST), we measured response inhibition (stop-signal reaction time-SSRT), sustained attention (defined as reaction time variability-RTV), and reaction time (RT). We controlled for comorbidity using ADHD and ASD trait scores and categorically-defined ADHD. Compared with controls, both clinic ADHD and ASD had significantly longer SSRT and RTV than controls and did not differ from each other. ADHD traits accounted for neurocognitive impairment in ASD, but not vice versa. There were no group differences for RT. Similar patterns of neurocognitive impairment were observed in the community sample. In the largest direct comparison of ADHD and ASD to date, we found impaired response inhibition and sustained attention in both disorders. However, neurocognitive impairment in ASD was almost completely accounted for by comorbid ADHD. Results generalized in the community sample indicating that referral bias alone did not drive results. Response inhibition and sustained attention likely play a role in ADHD and ASD.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Trastorno del Espectro Autista , Humanos , Trastorno del Espectro Autista/epidemiología , Trastorno del Espectro Autista/psicología , Atención/fisiología , Tiempo de Reacción/fisiología , Comorbilidad
11.
Mult Scler Relat Disord ; 69: 104457, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36512955

RESUMEN

BACKGROUND: Fatigue, a multidimensional and challenging symptom associated with various underlying conditions, can manifest as a subjective feeling and a performance fatigability. The latter is often defined as an objectively measurable performance decline with time on task. Both syndromes are highly prevalent in people with multiple sclerosis (pwMS) and are often resistant to medical therapy. In the absence of valid and reliable objective parameters, the current cognitive fatigue diagnosis remains purely subjective. Assessing brain wave activity changes has repeatedly been a viable strategy for monitoring cognitive fatigue in healthy subjects. In this study, we aimed to investigate oscillatory brain activity changes and their associations with subjective fatigue in pwMS. METHODS: We enrolled 21 pwMS and 21 healthy controls (HC) in this study. Subjects performed a sustained attention task divided into six blocks over the course of 30 minutes, and underwent resting state EEGs before and after the task. During the task, subjects were repeatedly asked to rate their subjective levels of mental fitness, mental exhaustion, and mind wandering. Using Linear Mixed Models, we explored fatigability-related changes by focusing on the time course of changes in reaction time variability, subjective ratings of fatigability, as well as frontomedial theta, and occipital alpha power. We further investigated initial and fatigability-induced differences between pwMS and HC at rest. Finally, Pearson correlations were used to examine the relationship between subjective fatigue and objective fatigability parameters. RESULTS: Our results revealed a systematically stronger fatigability development in pwMS that was objectively measurable. PwMS reported lower mental fitness levels and demonstrated greater variability in reaction times with time on task. Occipital alpha power significantly increased during the task. Especially for upper alpha power, this increase was significantly more prominent in pwMS compared to HC. However, the time-on-task-induced changes in our study were not associated with the subjective fatigue ratings. CONCLUSIONS: The results of this study expand the understanding of the neural mechanisms underlining cognitive fatigability and may complement the fatigue diagnosis and therapy monitoring with quantitative objective methods.


Asunto(s)
Esclerosis Múltiple , Humanos , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/psicología , Tiempo de Reacción , Ejercicio Físico , Atención , Encéfalo/diagnóstico por imagen
12.
J Child Adolesc Psychopharmacol ; 32(5): 250-277, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35704876

RESUMEN

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental conditions among school-age children. Early intervention and ongoing evaluation of treatment effectiveness are essential to minimize the life-long negative impact of ADHD. Neurocognitive functions have been reported to improve with pharmacological and cognitive training interventions for children with ADHD. We evaluated the value of measuring change in neurocognitive functions following ADHD interventions as a treatment outcome. We systematically reviewed randomized control trials of two distinctive types of ADHD interventions-pharmacological treatments and cognitive training-and summarized the changes in neurocognitive and clinical outcomes using a series of meta-analyses. Both pharmacological and cognitive training interventions showed positive effects on some aspects of neurocognitive functions. However, there were no significant correlations between changes in neurocognitive function (e.g., inhibition) and changes in ADHD behavioral symptoms (e.g., impulsive behavior). Although the associations between changes in neurocognitive function and clinical outcomes are not well studied, based on current findings, it is not suitable to use change in neurocognitive outcomes as a proxy for change in ADHD clinical symptom-based outcomes. There is, however, notable value in monitoring changes in neurocognitive function associated with ADHD interventions to achieve the following aims: (1) understanding full treatment effect on children with ADHD, (2) identifying ancillary indicators of subclinical changes, and (3) provision of objective and less biased measures of treatment effects. These findings are important evidence that changes in neurocognitive function could be a co-occurring objective indication that parallels the clinical effects of ADHD treatments.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/psicología , Niño , Cognición , Humanos , Resultado del Tratamiento
13.
Elife ; 112022 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-35608164

RESUMEN

In humans, ageing is characterized by decreased brain signal variability and increased behavioral variability. To understand how reduced brain variability segregates with increased behavioral variability, we investigated the association between reaction time variability, evoked brain responses and ongoing brain signal dynamics, in young (N=36) and older adults (N=39). We studied the electroencephalogram (EEG) and pupil size fluctuations to characterize the cortical and arousal responses elicited by a cued go/no-go task. Evoked responses were strongly modulated by slow (<2 Hz) fluctuations of the ongoing signals, which presented reduced power in the older participants. Although variability of the evoked responses was lower in the older participants, once we adjusted for the effect of the ongoing signal fluctuations, evoked responses were equally variable in both groups. Moreover, the modulation of the evoked responses caused by the ongoing signal fluctuations had no impact on reaction time, thereby explaining why although ongoing brain signal variability is decreased in older individuals, behavioral variability is not. Finally, we showed that adjusting for the effect of the ongoing signal was critical to unmask the link between neural responses and behavior as well as the link between task-related evoked EEG and pupil responses.


Asunto(s)
Envejecimiento , Encéfalo , Potenciales Evocados , Anciano , Envejecimiento/fisiología , Atención/fisiología , Conducta/fisiología , Encéfalo/fisiología , Electroencefalografía , Potenciales Evocados/fisiología , Humanos , Pupila/fisiología , Tiempo de Reacción/fisiología
14.
J Int Neuropsychol Soc ; 28(1): 12-21, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-33573707

RESUMEN

OBJECTIVE: Patients with Neurofibromatosis Type 1 (NF1) frequently display symptoms resembling those of Attention Deficit/Hyperactivity Disorder (ADHD). Importantly, these disorders are characterised by distinct changes in the dopaminergic system, which plays an important role in timing performance and feedback-based adjustments in timing performance. In a transdiagnostic approach, we examine how far NF1 and ADHD show distinct or comparable profiles of timing performance and feedback-based adjustments in timing. METHOD: We examined time estimation and learning processes in healthy control children (HC), children with ADHD with predominantly inattentive symptoms and those with NF1 using a feedback-based time estimation paradigm. RESULTS: Healthy controls consistently responded closer to the correct time window than both patient groups, were less variable in their reaction times and displayed intact learning-based adjustments across time. The patient groups did not differ from each other regarding the number of in-time responses. In ADHD patients, the performance was rather unstable across time. No performance changes could be observed in patients with NF1 across the entire task. CONCLUSIONS: Children with ADHD and NF1 differ in feedback learning-based adjustments of time estimation processes. ADHD is characterised by behavioural fluctuations during the learning process. These are likely to be associated with inefficiencies in the dopaminergic system. NF1 is characterised by impairments of feedback learning which could be due to various neurotransmitter alterations occurring in addition to deficits in dopamine synthesis. Results show that despite the strong overlap in clinical phenotype and neuropsychological deficits between NF1 and ADHD, the underlying cognitive mechanisms are different.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Neurofibromatosis 1 , Trastorno por Déficit de Atención con Hiperactividad/etiología , Cognición , Retroalimentación , Humanos , Neurofibromatosis 1/complicaciones , Tiempo de Reacción
15.
Psychol Med ; 52(14): 3150-3158, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-33531098

RESUMEN

BACKGROUND: A recent genome-wide association study (GWAS) identified 12 independent loci significantly associated with attention-deficit/hyperactivity disorder (ADHD). Polygenic risk scores (PRS), derived from the GWAS, can be used to assess genetic overlap between ADHD and other traits. Using ADHD samples from several international sites, we derived PRS for ADHD from the recent GWAS to test whether genetic variants that contribute to ADHD also influence two cognitive functions that show strong association with ADHD: attention regulation and response inhibition, captured by reaction time variability (RTV) and commission errors (CE). METHODS: The discovery GWAS included 19 099 ADHD cases and 34 194 control participants. The combined target sample included 845 people with ADHD (age: 8-40 years). RTV and CE were available from reaction time and response inhibition tasks. ADHD PRS were calculated from the GWAS using a leave-one-study-out approach. Regression analyses were run to investigate whether ADHD PRS were associated with CE and RTV. Results across sites were combined via random effect meta-analyses. RESULTS: When combining the studies in meta-analyses, results were significant for RTV (R2 = 0.011, ß = 0.088, p = 0.02) but not for CE (R2 = 0.011, ß = 0.013, p = 0.732). No significant association was found between ADHD PRS and RTV or CE in any sample individually (p > 0.10). CONCLUSIONS: We detected a significant association between PRS for ADHD and RTV (but not CE) in individuals with ADHD, suggesting that common genetic risk variants for ADHD influence attention regulation.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Disfunción Cognitiva , Adolescente , Adulto , Niño , Humanos , Adulto Joven , Trastorno por Déficit de Atención con Hiperactividad/genética , Trastorno por Déficit de Atención con Hiperactividad/psicología , Disfunción Cognitiva/genética , Estudio de Asociación del Genoma Completo , Fenotipo , Tiempo de Reacción/fisiología , Estudios de Casos y Controles
16.
Gait Posture ; 89: 206-210, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34340157

RESUMEN

INTRODUCTION: Greater double support time (DST) variability is associated with falls and memory decline. The underlying neurophysiological mechanisms of DST variability are poorly understood. Simple reaction time (SRT) variability, a measure of attention-processing speed is associated with falls and dementia and, may underlie greater DST variability. The aims of this study were to examine the association between SRT and DST variability and if SRT variability mediates the associations between poorer cognition/brain structure and DST variability. METHODS: Participants (n = 408) were community-dwelling older people without dementia (mean age 72.0 ± 7.0). DST variability was the standard deviation (SD) of DST, assessed with a walkway and averaged across steps of 6 walks. SRT variability was the SD of a button pressing task in response to a visual stimulus. Executive function and processing speed were assessed with neuropsychological tests. Magnetic Resonance Imaging was used to obtain cortical thickness (total and in frontal regions) and cerebral small vessel disease (cSVD). Multivariable linear regression models were used to examine the association between SRT and DST variability and if SRT variability mediated any associations of cognition/brain structure with DST variability. RESULTS: Greater SRT variability was associated with greater DST variability (p = 0.002). SRT variability partially mediated the association between poorer executive function and greater DST variability. Smaller mean thickness in orbitofrontal regions and greater cSVD burden were only associated with DST variability (p < 0.05), not with SRT variability (p > 0.05). CONCLUSIONS: Greater SRT variability, which may occur due to inefficient executive functioning, could be an underlying neurophysiological mechanism of greater DST variability.


Asunto(s)
Cognición , Marcha , Anciano , Función Ejecutiva , Humanos , Pruebas Neuropsicológicas , Tiempo de Reacción
17.
Brain Sci ; 11(5)2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-34068477

RESUMEN

Significant progress has been made in understanding the computational and neural mechanisms that mediate eye and hand movements made in isolation. However, less is known about the mechanisms that control these movements when they are coordinated. Here, we outline our computational approaches using accumulation-to-threshold and race-to-threshold models to elucidate the mechanisms that initiate and inhibit these movements. We suggest that, depending on the behavioral context, the initiation and inhibition of coordinated eye-hand movements can operate in two modes-coupled and decoupled. The coupled mode operates when the task context requires a tight coupling between the effectors; a common command initiates both effectors, and a unitary inhibitory process is responsible for stopping them. Conversely, the decoupled mode operates when the task context demands weaker coupling between the effectors; separate commands initiate the eye and hand, and separate inhibitory processes are responsible for stopping them. We hypothesize that the higher-order control processes assess the behavioral context and choose the most appropriate mode. This computational mechanism can explain the heterogeneous results observed across many studies that have investigated the control of coordinated eye-hand movements and may also serve as a general framework to understand the control of complex multi-effector movements.

18.
Neurosci Res ; 172: 51-62, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34015393

RESUMEN

There is trial-to-trial variability in the reaction time to stimulus presentation. Since this variability exists even in an identical stimulus condition, it reflects the internal neural dynamics of the brain. To understand the neural dynamics that influence the reaction time, we conducted an electroencephalogram (EEG) experiment in which participants were asked to press a response button as quickly as possible when a stimulus was visually presented. Phase-locking factor analysis revealed that phase resetting in two frequency bands, which appeared 0.2 s after the stimulus presentation, characterized the reaction time. The combination of the theta band phase resetting in the left parietal region and the delta band phase resetting mainly in the posterior region was associated with the fastest reaction time, whereas delta band phase resetting without theta band phase resetting was associated with the faster reaction time. The results indicated that there were frequency-dependent effects in the relationships between the EEG phase resetting and reaction time.


Asunto(s)
Trastornos Mentales , Ritmo Teta , Encéfalo , Electroencefalografía , Humanos , Tiempo de Reacción
19.
Dev Psychobiol ; 63(4): 713-724, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-32974928

RESUMEN

Trial-to-trial intraindividual reaction time variability (IIRTV) serves as an index of attentional control and related endogenous brain function. What determinants contribute to preschoolers' attentional control indexed by IIRTV remains unknown. The present study examined how catechol-o-methyltransferase (COMT) rs4680 polymorphism interacted with family functioning (cohesion and adaptability) to impact on preschoolers' attentional control indexed by IIRTV. One hundred forty-four preschool children (Mage  = 4.19, SD = 0.63) completed the flanker task to assess their IIRTV. Their parents were asked to fill out the Family Adaptability and Cohesion Evaluation Scale II to assess family functioning. After controlling for age, socioeconomic status (SES) and mean reaction time, results showed that the COMT rs4680 polymorphism was positively associated with preschoolers' IIRTV at the 5% significance level (p = .02) but not after multiple testing adjustment (p = .08). Moreover the COMT rs4680 polymorphism significantly interacted with family functioning to impact on preschoolers' IIRTV and the interaction effects remained significant after correction for multiple testing (p = .01, ΔR2  = 0.06 in congruent conditions; p = .04, ΔR2  = 0.04 in combined conditions). In addition, the significant interaction between SES and COMT rs4680 polymorphism was also found in the present study (p = .01, ΔR2  = 0.05 in congruent conditions; p = .05, ΔR2  = 0.03 in combined conditions). No sex differences were found in the present sample. The findings of the present study expand our knowledge about the gene × environment underpinnings of children's attentional control and endogenous brain function, and provide evidence for the Vantage Sensitivity model on children's development.


Asunto(s)
Atención , Catecol O-Metiltransferasa , Catecol O-Metiltransferasa/genética , Preescolar , Genotipo , Humanos , Padres , Polimorfismo de Nucleótido Simple , Tiempo de Reacción
20.
J Exp Child Psychol ; 202: 105011, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33091822

RESUMEN

The current study investigated whether trial-to-trial intraindividual reaction time variability (IIRTV), which serves as an index of attentional control fluctuations, moderates the effect of marital quality at 7 years of age on the development of children's externalizing problems from 7 to 9 years of age (N = 197). At the first assessment (T1), a flanker task was administered to children for assessing their IIRTV. The Chinese version of a marital quality questionnaire (Evaluating and Nurturing Relationship Issues, Communication, and Happiness [ENRICH]) and the Chinese version of the Child Behavior Checklist (CBCL) were completed by children's mothers to assess marital quality and children's externalizing problems. At the second and third assessments (T2 and T3), children's externalizing problems were reassessed by their mothers. Growth curve analyses showed that boys' externalizing problems were relatively high and significantly decreased over time, whereas girls' externalizing problems were relatively low and stable. Importantly, the results indicated that boys' IIRTV (but not girls' IIRTV) and parental marital quality interactively predict the concurrent and developmental trajectories of externalizing problems. Specifically, boys with greater IIRTV were found to exhibit a relatively persistent high level of externalizing problems in the context of poor parental marital quality, whereas boys with lower IIRTV were found to exhibit a relatively low level of externalizing problems over time regardless of their parental marital quality. The findings suggest that poorer attentional control indexed by greater IIRTV is a robust predictor of boys' externalizing problems and that better attentional control indexed by lower IIRTV may buffer the negative impact of adverse family environment on the development of boys' externalizing problems.


Asunto(s)
Atención , Trastornos de la Conducta Infantil/psicología , Conducta Infantil , Matrimonio/psicología , Padres/psicología , Tiempo de Reacción , Adulto , Niño , Femenino , Humanos , Masculino
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