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1.
J Neurosci ; 43(15): 2730-2740, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-36868858

RESUMO

Behavioral reports of sensory information are biased by stimulus history. The nature and direction of such serial-dependence biases can differ between experimental settings; both attractive and repulsive biases toward previous stimuli have been observed. How and when these biases arise in the human brain remains largely unexplored. They could occur either via a change in sensory processing itself and/or during postperceptual processes such as maintenance or decision-making. To address this, we tested 20 participants (11 female) and analyzed behavioral and magnetoencephalographic (MEG) data from a working-memory task in which participants were sequentially presented with two randomly oriented gratings, one of which was cued for recall at the end of the trial. Behavioral responses showed evidence for two distinct biases: (1) a within-trial repulsive bias away from the previously encoded orientation on the same trial, and (2) a between-trial attractive bias toward the task-relevant orientation on the previous trial. Multivariate classification of stimulus orientation revealed that neural representations during stimulus encoding were biased away from the previous grating orientation, regardless of whether we considered the within-trial or between-trial prior orientation, despite opposite effects on behavior. These results suggest that repulsive biases occur at the level of sensory processing and can be overridden at postperceptual stages to result in attractive biases in behavior.SIGNIFICANCE STATEMENT Recent experience biases behavioral reports of sensory information, possibly capitalizing on the temporal regularity in our environment. It is still unclear at what stage of stimulus processing such serial biases arise. Here, we recorded behavior and neurophysiological [magnetoencephalographic (MEG)] data to test whether neural activity patterns during early sensory processing show the same biases seen in participants' reports. In a working-memory task that produced multiple biases in behavior, responses were biased toward previous targets, but away from more recent stimuli. Neural activity patterns were uniformly biased away from all previously relevant items. Our results contradict proposals that all serial biases arise at an early sensory processing stage. Instead, neural activity exhibited mostly adaptation-like responses to recent stimuli.


Assuntos
Memória de Curto Prazo , Percepção Visual , Humanos , Feminino , Percepção Visual/fisiologia , Memória de Curto Prazo/fisiologia , Cognição , Encéfalo , Sinais (Psicologia)
2.
J Neurosci ; 42(9): 1804-1819, 2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-35042770

RESUMO

Value-based decision-making is often studied in a static context, where participants decide which option to select from those currently available. However, everyday life often involves an additional dimension: deciding when to select to maximize reward. Recent evidence suggests that agents track the latent reward of an option, updating changes in their latent reward estimate, to achieve appropriate selection timing (latent reward tracking). However, this strategy can be difficult to distinguish from one in which the optimal selection time is estimated in advance, allowing an agent to wait a predetermined amount of time before selecting, without needing to monitor an option's latent reward (distance-to-goal tracking). Here, we show that these strategies can in principle be dissociated. Human brain activity was recorded using electroencephalography (EEG), while female and male participants performed a novel decision task. Participants were shown an option and decided when to select it, as its latent reward changed from trial-to-trial. While the latent reward was uncued, it could be estimated using cued information about the option's starting value and value growth rate. We then used representational similarity analysis (RSA) to assess whether EEG signals more closely resembled latent reward tracking or distance-to-goal tracking. This approach successfully dissociated the strategies in this task. Starting value and growth rate were translated into a distance-to-goal signal, far in advance of selecting the option. Latent reward could not be independently decoded. These results demonstrate the feasibility of using high temporal resolution neural recordings to identify internally computed decision variables in the human brain.SIGNIFICANCE STATEMENT Reward-seeking behavior involves acting at the right time. However, the external world does not always tell us when an action is most rewarding, necessitating internal representations that guide action timing. Specifying this internal neural representation is challenging because it might stem from a variety of strategies, many of which make similar predictions about brain activity. This study used a novel approach to test whether alternative strategies could be dissociated in principle. Using representational similarity analysis (RSA), we were able to distinguish between candidate internal representations for selection timing. This shows how pattern analysis methods can be used to measure latent decision information in noninvasive neural data.


Assuntos
Sinais (Psicologia) , Recompensa , Encéfalo , Comportamento de Escolha , Tomada de Decisões , Eletroencefalografia , Feminino , Humanos , Masculino , Estudos Prospectivos
3.
Prev Sci ; 24(2): 286-298, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-34173135

RESUMO

Fun For Wellness (FFW) is a self-efficacy theory-based online behavioral intervention that aims to promote growth in physical activity and well-being. The FFW conceptual model for the promotion of subjective well-being posits that FFW exerts both a positive direct effect, and a positive indirect effect through well-being self-efficacy, on subjective well-being. Subjective well-being is defined in FFW as an individual's satisfaction with their status in seven key domains of their life. Well-being self-efficacy is defined in FFW as the degree to which an individual perceives that they have the capability to attain a positive status in seven key domains of their life. The objective of this study was to use baseline target moderation to assess variation in the impact of FFW on subjective well-being dimensions in adults with obesity. Data (N = 667) from the Well-Being and Physical Activity Study (ClinicalTrials.gov, identifier: NCT03194854) were reanalyzed. There was evidence that well-being self-efficacy at baseline moderated the direct effect of FFW on well-being self-efficacy at 30 days post-baseline for the occupational and psychological dimensions. Both of these findings suggest a "compensatory" effect. Similarly, there was evidence that well-being self-efficacy at baseline moderated the indirect effect of FFW on subjective well-being at 60 days post-baseline through well-being self-efficacy at 30 days post-baseline for the occupational and psychological dimensions. Both of these findings suggest a "compensatory" effect. Finally, there was evidence that well-being self-efficacy at baseline moderated the direct effect of FFW on subjective well-being at 60 days post-baseline for the community, occupational, and physical dimensions. Each of these three findings suggests some version of a "rich-get-richer" effect. In summary, results provide both supportive and unsupportive (i.e., interpersonal, economic, and overall dimensions) evidence regarding variation in the impact of the FFW intervention and should impact the design of future FFW trials.


Assuntos
Exercício Físico , Obesidade , Humanos , Adulto , Autoeficácia
4.
Behav Med ; 49(3): 213-230, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35465851

RESUMO

Use of information and communication technology to improve health, known as eHealth, is an emerging concept in healthcare that may present opportunities to promote physical activity in adults with obesity. The purpose of this research was to systematically review eHealth intervention studies to promote physical activity in adults with obesity. Five electronic databases were used. Two authors screened articles, assessed risk of bias, and extracted data independently. A qualitative data synthesis for summarizing the findings was performed using harvest plots. In the search, 2276 articles were identified, and 18 studies met all inclusion criteria. Study quality ranged from poor to good. The included studies varied in intervention technology (e.g., web-based), physical activity assessment (e.g., device-based), and control group (e.g., wait-list). Behavioral change techniques used in the included studies were consistent with some techniques (e.g., self-monitoring) known as effective in face-to-face interventions, but more efficiently employed in eHealth using information and communication technology. Overall, this systematic review showed that a web-based or physical activity monitor-based eHealth intervention had the potential to effectively promote physical activity in adults with obesity. Some recommendations for future eHealth interventions to promote physical activity in adults with obesity were provided (e.g., use of theory, accelerometers).

5.
J Neurosci ; 41(20): 4461-4475, 2021 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-33888611

RESUMO

Extensive research has examined how information is maintained in working memory (WM), but it remains unknown how WM is used to guide behavior. We addressed this question by combining human electrophysiology (50 subjects, male and female) with pattern analyses, cognitive modeling, and a task requiring the prolonged maintenance of two WM items and priority shifts between them. This enabled us to discern neural states coding for memories that were selected to guide the next decision from states coding for concurrently held memories that were maintained for later use, and to examine how these states contribute to WM-based decisions. Selected memories were encoded in a functionally active state. This state was reflected in spontaneous brain activity during the delay period, closely tracked moment-to-moment fluctuations in the quality of evidence integration, and also predicted when memories would interfere with each other. In contrast, concurrently held memories were encoded in a functionally latent state. This state was reflected only in stimulus-evoked brain activity, tracked memory precision at longer timescales, but did not engage with ongoing decision dynamics. Intriguingly, the two functional states were highly flexible, as priority could be dynamically shifted back and forth between memories without degrading their precision. These results delineate a hierarchy of functional states, whereby latent memories supporting general maintenance are transformed into active decision circuits to guide flexible behavior.SIGNIFICANCE STATEMENT Working memory enables maintenance of information that is no longer available in the environment. Abundant neuroscientific work has examined where in the brain working memories are stored, but it remains unknown how they are represented and used to guide behavior. Our study shows that working memories are represented in qualitatively different formats, depending on behavioral priorities. Memories that are selected for guiding behavior are encoded in an active state that transforms sensory input into decision variables, whereas other concurrently held memories are encoded in a latent state that supports precise maintenance without affecting ongoing cognition. These results dissociate mechanisms supporting memory storage and usage, and open the door to reveal not only where memories are stored but also how.


Assuntos
Encéfalo/fisiologia , Memória de Curto Prazo/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Modelos Neurológicos , Adulto Jovem
6.
J Cogn Neurosci ; 35(1): 11-13, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36166306

RESUMO

While working memory (WM) allows us to store past information, its function is to guide future behavior. Given this role, the tight link between how WMs are maintained and how they are read out to be transformed into context-appropriate actions remains relatively unexplored. Beyond helping us understand memory-guided behavior, focusing on WM readout may also help us better understand the neural basis of memory maintenance.


Assuntos
Memória de Curto Prazo , Humanos
7.
J Cogn Neurosci ; 34(9): 1681-1701, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35704549

RESUMO

Attention can be allocated in working memory (WM) to select and privilege relevant content. It is unclear whether attention selects individual features or whole objects in WM. Here, we used behavioral measures, eye-tracking, and EEG to test the hypothesis that attention spreads between an object's features in WM. Twenty-six participants completed a WM task that asked them to recall the angle of one of two oriented, colored bars after a delay while EEG and eye-tracking data were collected. During the delay, an orthogonal "incidental task" cued the color of one item for a match/mismatch judgment. On congruent trials (50%), the cued item was probed for subsequent orientation recall; on incongruent trials (50%), the other memory item was probed. As predicted, selecting the color of an object in WM brought other features of the cued object into an attended state as revealed by EEG decoding, oscillatory α-power, gaze bias, and improved orientation recall performance. Together, the results show that attentional selection spreads between an object's features in WM, consistent with object-based attentional selection. Analyses of neural processing at recall revealed that the selected object was automatically compared with the probe, whether it was the target for recall or not. This provides a potential mechanism for the observed benefits of nonpredictive cueing in WM, where a selected item is prioritized for subsequent decision-making.


Assuntos
Atenção , Memória de Curto Prazo , Sinais (Psicologia) , Humanos , Rememoração Mental
8.
J Cogn Neurosci ; 35(1): 44-48, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36306261

RESUMO

The transition to principal investigator (PI), or lab leader, can be challenging, partially due to the need to fulfil new managerial and leadership responsibilities. One key aspect of this role, which is often not explicitly discussed, is creating a supportive lab environment. Here, we present ten simple rules to guide the new PI in the development of their own positive and thriving lab atmosphere. These rules were written and voted on collaboratively, by the students and mentees of Professor Mark Stokes, who inspired this piece.

9.
BMC Public Health ; 22(1): 1544, 2022 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-35964114

RESUMO

BACKGROUND: Promoting health-enhancing and sustainable physical activity levels across childhood and adolescence contribute to positive health outcomes as an adult. This study will aim to: a) examine the immediate (pre- to post-intervention) and sustained (1-year post-intervention follow-up) effects of the Children's Health Activity Motor Program-Afterschool Program (CHAMP-ASP) on physical activity, motor competence, and perceived motor competence relative to the comparison ASP, b) examine the immediate and sustained effects of CHAMP-ASP on secondary health outcomes, specifically health-related physical fitness (i.e., cardiorespiratory fitness, muscular strength, percent body fat) and weight status compared to children in the comparison ASP, and c) determine if perceived motor competence mediates the effect of CHAMP-ASP on moderate-to-vigorous physical activity. METHODS: This multicenter cluster randomized trial will be implemented by ASP staff and will be conducted in ASPs located in two city-based cohorts: East Lansing/Lansing and Ann Arbor/Ypsilanti, Michigan. Children (N = 264) who are K-2 graders will participate 35 min/day X 3 days/week for 19 weeks (1995 min) in their afterschool movement program (i.e., CHAMP-ASP vs. comparison). The research team will train ASP staff to implement the program, which will be delivered within the existing ASP offering. Measures of physical activity (accelerometer), motor competence (process and product measures of fundamental motor skills), health-related fitness, perceived motor competence, and anthropometry will be collected pre-, immediately post-, and one-year post-intervention. Random-effects models will be used to assess the clustered longitudinal effect of the intervention on outcome measures. DISCUSSION: The long-term goal is to provide a sustainable, ecologically-relevant, and evidence-based program during the early elementary years that can be delivered by ASP staff, is health-enhancing, and increases physical activity in children. Findings hold the potential to help shape public health and educational policies and interventions that support healthy development and active living during the early years. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT05342701 . ETHICS AND DISSEMINATION: Ethical approval was obtained through the Health Sciences and Behavioral Sciences IRB, University of Michigan (HUM00208311). The CHAMP-ASP study is funded by the National Institutes of Health. Findings will be disseminated via print, online media, dissemination events, and practitioner and/or research journals.


Assuntos
Exercício Físico , Destreza Motora , Criança , Nível de Saúde , Humanos , Motivação , Estudos Multicêntricos como Assunto , Aptidão Física , Ensaios Clínicos Controlados Aleatórios como Assunto , Estados Unidos
10.
Cogn Behav Ther ; 50(2): 104-120, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33073722

RESUMO

Although considerable research has highlighted the importance of cognitive and metacognitive beliefs in adult obsessive-compulsive disorder (OCD), there has been limited investigation of these beliefs in pediatric OCD. The present study investigated the clinical correlates of cognitive and metacognitive beliefs in pediatric OCD. Previous studies found positive relations between OCD symptoms and these beliefs in pediatric patients, and we hypothesized these beliefs would also be positively related to pediatric OCD symptom severity. We additionally hypothesized age would moderate these relationships in consideration of previous studies highlighting age differences in symptom presentation and self-reported beliefs. We also explored age differences in belief endorsements. Youth aged 7-17 (n = 142) diagnosed with OCD completed self-report scales to measure cognitive and meta-cognitive beliefs. OCD severity was assessed using self-report and clinician-rated measures. Pearson correlations, moderation analyses, and independent-samples t-tests were used to test our hypotheses and aims. Significant positive relationships were observed between cognitive and metacognitive beliefs and self-reported OCD severity, although age did not moderate these relationships. Age differences were found in belief endorsements. In conclusion, cognitive and metacognitive beliefs appear clinically relevant to pediatric OCD cases, and we recommend clinicians assess these beliefs and incorporate cognitive components to corresponding evidence-based treatment.


Assuntos
Envelhecimento/psicologia , Metacognição , Transtorno Obsessivo-Compulsivo/psicologia , Adolescente , Criança , Feminino , Humanos , Masculino , Autorrelato , Inquéritos e Questionários
11.
J Sport Exerc Psychol ; 43(6): 497-513, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34794118

RESUMO

The objective of this study was to improve the measurement of physical activity self-efficacy (PASE) in adults with obesity. To accomplish this objective, a latent variable approach was used to explore dimensionality, temporal invariance, and external validity of responses to a newly developed battery of PASE scales. Data (Nbaseline = 461 and N30 days postbaseline = 427) from the Well-Being and Physical Activity Study (ClinicalTrials.gov, identifier: NCT03194854), which deployed the Fun For Wellness intervention, were analyzed. A two-dimensional factor structure explained responses to each PASE scale at baseline. There was strong evidence for at least partial temporal measurement invariance for this two-dimensional structure in each PASE scale. There was mixed evidence that the effectiveness of the Fun For Wellness intervention exerted a direct effect on latent PASE in adults with obesity at 30 days postbaseline (i.e., external validity) of this two-dimensional structure.


Assuntos
Exercício Físico , Autoeficácia , Adulto , Humanos , Obesidade , Psicometria , Reprodutibilidade dos Testes
12.
J Neurosci ; 39(49): 9806-9817, 2019 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-31662425

RESUMO

Temporal orienting improves sensory processing, akin to other top-down biases. However, it is unknown whether these improvements reflect increased neural gain to any stimuli presented at expected time points, or specific tuning to task-relevant stimulus aspects. Furthermore, while other top-down biases are selective, the extent of trade-offs across time is less well characterized. Here, we tested whether gain and/or tuning of auditory frequency processing in humans is modulated by rhythmic temporal expectations, and whether these modulations are specific to time points relevant for task performance. Healthy participants (N = 23) of either sex performed an auditory discrimination task while their brain activity was measured using magnetoencephalography/electroencephalography (M/EEG). Acoustic stimulation consisted of sequences of brief distractors interspersed with targets, presented in a rhythmic or jittered way. Target rhythmicity not only improved behavioral discrimination accuracy and M/EEG-based decoding of targets, but also of irrelevant distractors preceding these targets. To explain this finding in terms of increased sensitivity and/or sharpened tuning to auditory frequency, we estimated tuning curves based on M/EEG decoding results, with separate parameters describing gain and sharpness. The effect of rhythmic expectation on distractor decoding was linked to gain increase only, suggesting increased neural sensitivity to any stimuli presented at relevant time points.SIGNIFICANCE STATEMENT Being able to predict when an event may happen can improve perception and action related to this event, likely due to the alignment of neural activity to the temporal structure of stimulus streams. However, it is unclear whether rhythmic increases in neural sensitivity are specific to task-relevant targets, and whether they competitively impair stimulus processing at unexpected time points. By combining magnetoencephalography and encephalographic recordings, neural decoding of auditory stimulus features, and modeling, we found that rhythmic expectation improved neural decoding of both relevant targets and irrelevant distractors presented and expected time points, but did not competitively impair stimulus processing at unexpected time points. Using a quantitative model, these results were linked to nonspecific neural gain increases due to rhythmic expectation.


Assuntos
Antecipação Psicológica/fisiologia , Percepção da Altura Sonora/fisiologia , Estimulação Acústica , Adolescente , Adulto , Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Discriminação Psicológica/fisiologia , Eletroencefalografia , Feminino , Voluntários Saudáveis , Humanos , Magnetoencefalografia , Masculino , Desempenho Psicomotor/fisiologia , Adulto Jovem
13.
J Neurosci ; 39(43): 8549-8561, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31519820

RESUMO

Cognitive flexibility is critical for intelligent behavior. However, its execution is effortful and often suboptimal. Recent work indicates that flexible behavior can be improved by the prospect of reward, which suggests that rewards optimize flexible control processes. Here we investigated how different reward prospects influence neural encoding of task rule information to optimize cognitive flexibility. We applied representational similarity analysis to human electroencephalograms, recorded while female and male participants performed a rule-guided decision-making task. During the task, the prospect of reward varied from trial to trial. Participants made faster, more accurate judgements on high-reward trials. Critically, high reward boosted neural coding of the active task rule, and the extent of this increase was associated with improvements in task performance. Additionally, the effect of high reward on task rule coding was most pronounced on switch trials, where rules were updated relative to the previous trial. These results suggest that reward prospect can promote cognitive performance by strengthening neural coding of task rule information, helping to improve cognitive flexibility during complex behavior.SIGNIFICANCE STATEMENT The importance of motivation is evident in the ubiquity with which reward prospect guides adaptive behavior and the striking number of neurological conditions associated with motivational impairments. In this study, we investigated how dynamic changes in motivation, as manipulated through reward, shape neural coding for task rules during a flexible decision-making task. The results of this work suggest that motivation to obtain reward modulates the encoding of task rules needed for flexible behavior. The extent to which reward increased task rule coding also tracked improvements in behavioral performance under high-reward conditions. These findings help to inform how motivation shapes neural processing in the healthy human brain.


Assuntos
Encéfalo/fisiologia , Cognição/fisiologia , Função Executiva/fisiologia , Julgamento/fisiologia , Recompensa , Adolescente , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Adulto Jovem
14.
Cereb Cortex ; 29(2): 863-874, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30535141

RESUMO

In this article, we propose a method to track trial-specific neural dynamics of stimulus processing and decision making with high temporal precision. By applying this novel method to a perceptual template-matching task, we tracked representational brain states associated with the cascade of neural processing, from early sensory areas to higher order areas that are involved in integration and decision making. We address a major limitation of the traditional decoding approach: that it relies on consistent timing of these processes over trials. Using a TUDA approach, we found that the timing of the cognitive processes involved in perceptual judgments can vary considerably over trials. This revealed that the sequence of processing states was consistent for all subjects and trials, even when the timing of these states varied. Furthermore, we found that the specific timing of states on each trial was related to the quality of performance over trials. Altogether, this work not only highlights the serious pitfalls and misleading interpretations that result from assuming stimulus processing to be synchronous across trials but can also open important avenues to investigate learning and quantify plasticity.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Tomada de Decisões/fisiologia , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Estimulação Luminosa/métodos , Adulto Jovem
15.
J Strength Cond Res ; 34(9): 2434-2442, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32732774

RESUMO

Feltz, DL, Hill, CR, Samendinger, S, Myers, ND, Pivarnik, JM, Winn, B, Ede, A, and Ploutz-Snyder, L. Can simulated partners boost workout effort in long-term exercise? J Strength Cond Res 34(9): 2434-2442, 2020-We tested whether exercising with a stronger simulated (i.e., software-generated) partner leads to greater work effort compared to exercising alone, to help those seeking to maintain or improve fitness levels with long-term high-intensity training, but who find it necessary or practical to exercise in social isolation. Forty-one middle-aged adults, who participated in at least 30 minutes of vigorous exercise 3x·wk, trained on a cycle ergometer 6 days per week for 24 weeks in an alternating regimen of moderate-intensity 30-minute continuous and 3 types of high-intensity interval sessions (8 × 30-second sprints, 6 × 2-minute ladders, and 4 × 4-minute intervals). They were assigned either no partner (control), an always superior partner, or a not always superior partner. Participants varied cycle power output to increase or decrease session intensity during the repeated moderate-intensity sessions (30-minute continuous) and 1 of the 3 high-intensity sessions (4 × 4-minute intervals). Changes in intensity were used as a measure of effort motivation over time. Nested multilevel models of effort trajectory were developed and alpha was set to 0.05. For continuous and interval sessions, effort trajectory was positive and significant for those with an always superior partner, but not significantly different from control. Within interval sessions, those with an always superior partner significantly increased effort in the fourth interval compared to control (p = 0.02). Exercising with an always superior partner leads to greater work efforts during the hardest interval training compared to exercising alone.


Assuntos
Ciclismo/fisiologia , Treinamento Intervalado de Alta Intensidade/métodos , Realidade Virtual , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Consumo de Oxigênio
16.
J Sport Exerc Psychol ; 43(1): 83-96, 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33333492

RESUMO

The purpose of this study was to evaluate the effectiveness of the Fun For Wellness (FFW) online intervention to increase well-being actions in adults with obesity in the United States in relatively uncontrolled settings. The FFW intervention is guided by self-efficacy theory. The study design was a large-scale, prospective, double-blind, and parallel-group randomized controlled trial. Data collection occurred at baseline, 30 days after baseline, and 60 days after baseline. Participants (N = 667) who were assigned to the FFW group (nFFW = 331) were provided with 30 days of 24-hr access to FFW. Supportive evidence was provided for the effectiveness of FFW in real-world settings to promote, either directly or indirectly, three dimensions of well-being actions: community, occupational, and psychological. This study shows that theory-based intervention may be effective in promoting well-being actions in adults with obesity in the United States.


Assuntos
Intervenção Baseada em Internet , Sobrepeso , Adulto , Método Duplo-Cego , Humanos , Obesidade , Sobrepeso/terapia , Estudos Prospectivos
17.
J Trauma Dissociation ; 21(3): 319-336, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32000621

RESUMO

Children that have been maltreated may experience manifold negative effects later in life. Two such sequelae are social anxiety and dissociation. Recent studies have noted their frequent co-occurrence, but no hypothesis has yet been offered explaining how they interact. College undergraduates (N = 198) completed the Child Trauma Questionnaire, Liebowitz Social Anxiety Scale, and Cambridge Depersonalization Scale. Social anxiety significantly predicted severity of dissociation, and self-reported childhood maltreatment (CM) significantly predicted both social anxiety and dissociation. Notably, emotional abuse was the only significant subtype of CM to predict social anxiety. Furthermore, CM moderated the relationship between social anxiety and dissociation, such that the presence of CM strengthened the predictive effect of social anxiety on dissociation. This study was the first to implicate CM as a mechanism in the social anxiety-dissociation relationship. This study was also the first to note a social anxiety-dissociation link in a non-clinical sample, thus demonstrating the existence of this relationship along a continuum of severity - not solely for those with extreme disturbances.


Assuntos
Sobreviventes Adultos de Maus-Tratos Infantis/psicologia , Transtornos de Ansiedade/psicologia , Transtornos Dissociativos/psicologia , Despersonalização/psicologia , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Fatores de Risco , Estados Unidos , Adulto Jovem
18.
Neuroimage ; 194: 163-173, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30905834

RESUMO

Working memory (WM) is essential for normal cognitive function, but shows marked decline in aging. The importance of selective attention in guiding WM performance is increasingly recognized. Studies so far are inconclusive about the ability to use selective attention during WM in aging. To investigate the neural mechanisms supporting selective attention in WM in aging, we tested a large group of older adults using functional magnetic resonance imaging whilst they performed a category-based (faces/houses) selective-WM task. Older adults were able to use attention to encode targets and suppress distractors to reach high levels of task performance. A subsequent, surprise recognition-memory task showed strong consequences of selective attention. Attended items in the relevant category were recognized significantly better than items in the ignored category. Neural measures also showed reliable markers of selective attention during WM. Purported control regions including the dorsolateral and inferior prefrontal and anterior cingulate cortex were reliably recruited for attention to both categories. Activation levels in category-sensitive visual cortex showed reliable modulation according to attentional demands, and positively correlated with subsequent memory measures of attention and WM span. Psychophysiological interaction analyses showed that activity in category-sensitive areas were coupled with non-sensory cortex known to be involved in cognitive control and memory processing, including regions in the prefrontal cortex and hippocampus. In summary, we found that older adults were able to recruit a network of brain regions involved in top-down attention during selective WM, and individual differences in attentional control corresponded to the degree of attention-related modulation in the brain.


Assuntos
Atenção/fisiologia , Envelhecimento Saudável/fisiologia , Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade
19.
Inorg Chem ; 58(20): 14112-14119, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31556996

RESUMO

The effects of radiation on a variety of uranyl peroxide compounds were examined using γ-rays and 5 MeV He ions, the latter to simulate α-particles. The studied materials were studtite, [(UO2)(O2)(H2O)2](H2O)2, the salt of the U60 uranyl peroxide cage cluster, Li44K16[(UO2)(O2)(OH)]60·255H2O, the salt of U60Ox30 uranyl peroxide oxalate cage cluster, Li12K48[{(UO2)(O2)}60(C2O4)30]·nH2O, and the salt of the U24Pp12 (Pp = pyrophosphate) uranyl peroxide pyrophosphate cage cluster, Li24Na24[(UO2)24(O2)24(P2O7)12]·120H2O. Irradiated powders were characterized using powder X-ray diffraction, Raman spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, and UV-vis spectroscopy. A weakening of the uranyl bonds of U60 was found while studtite, U60Ox30, and U24Pp12 were relatively stable to γ-irradiation. Studtite and U60 are the most affected by α-irradiation forming an amorphous uranyl peroxide as characterized by Raman spectroscopy and powder X-ray diffraction while U60Ox30 and U24Pp12 show minor signs of the formation of an amorphous uranyl peroxide.

20.
BMC Public Health ; 19(1): 737, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31196052

RESUMO

BACKGROUND: Fun For Wellness (FFW) is an online behavioral intervention developed to encourage growth in well-being by providing capability-enhancing learning opportunities to participants. Self-efficacy theory guides the conceptual model underlying the FFW intervention. Some initial evidence has been provided for the efficacy of FFW to promote: well-being self-efficacy; interpersonal, community, psychological and economic subjective well-being; and, interpersonal and physical well-being actions. The purpose of this paper is to describe the protocol for a new randomized controlled trial (RCT) designed to provide the first investigation of the effectiveness of FFW to increase well-being and physical activity in adults with obesity in the United States of America. METHODS: The study design is a large-scale, prospective, parallel group RCT. Approximately 9 hundred participants will be randomly assigned to the FFW or Usual Care (UC) group to achieve a 1:1 group (i.e. , FFW: UC) assignment. Participants will be recruited through an online panel recruitment company. Data collection, including determination of eligibility, will be conducted online and enrollment is scheduled to begin on 8 August 2018. Data collection will occur at baseline, 30 days and 60 days after baseline. Instruments to measure demographic information, anthropometric characteristics, self-efficacy, physical activity and well-being will be included in the battery. Data will be modeled under an intent to treat approach and/or a complier average causal effect approach depending on the level of observed engagement with the intervention. DISCUSSION: The effectiveness trial described in this paper builds upon the 2015 FFW efficacy trial and has the potential to be important for at least three reasons. The first reason is based upon a general scientific approach that the potential utility of interventions should be evaluated under both ideal (e.g., more controlled) and real-world (e.g., less controlled) conditions. The second reason is based upon the global need for readily scalable online behavioral interventions that effectively promote physical activity in adults. The third reason is based upon the troubling global trend toward obesity along with evidence for obesity as a risk factor for several major non-communicable diseases. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT03194854 , registered 21 June 2017.


Assuntos
Terapia Comportamental/métodos , Exercício Físico/psicologia , Promoção da Saúde/métodos , Internet , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Projetos de Pesquisa , Autoeficácia , Adulto Jovem
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