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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Implicit Measurement of Racial Identity and Coping Responses to Racism in African Americans

Smith, Veronica J 09 June 2006 (has links)
African Americans’ experiences of racism have been found to be linked with higher levels of psychological distress. Coping responses to racism and racial identity may serve as moderators to this relationship. The present study uses an implicit measure to assess coping responses and racial identity. The main goal was to determine any correlation between implicit and explicit coping responses and racial identity, and between implicit coping responses to racism and explicit coping responses to general stress. A significant correlation was observed between implicit and explicit measures of coping responses and racial identity, and between implicit coping responses to racism and explicit coping responses to general stress. A significant correlation was also observed between implicit coping responses to racism and psychological distress. Findings indicate that implicit measures used in conjunction with explicit measures may provide a more comprehensive assessment of coping responses to racism and racial identity.
22

DIAPHRAGMATIC BREATHING AND ITS EFFECT ON INHIBITORY CONTROL

Russell, Matthew 01 January 2014 (has links)
Evidence suggests that slow paced diaphragmatic breathing (DB) can significantly affect prefrontal cortex functions through increasing an individual’s physiological self-regulatory capacity. The current research demonstrates the effects of paced DB on inhibitory control, which is considered to be a reliable measure of behavioral self-regulation. Eighty healthy participants were randomly assigned to one of two conditions (20 males and females each). Participants were instructed on either DB at a pace of six-breaths per minute (BPM) or instructions on environmental awareness and asked to breathe at 12 BPM. Following training, all participants completed a computer-based task designed to examine inhibitory processes. Physiological recordings of heart rate (HR), BPM, and HRV were collected at baseline, during the breathing training, during the cued go/no-go task, and after the cued go/no-go task. The findings demonstrated that the DB condition had significantly lower BPM, HR, and higher HRV (p’s<0.05) during active training than the environmental awareness condition. Furthermore, the DB condition performed significantly better on the measure of inhibition than the environmental awareness condition (p<0.05). The use of DB as a reliable method to increase physiological self-regulatory capacity and improve behavioral self-regulation, measured as inhibitory control, should continue to be explored.
23

Optimal decision criteria for the study design and sample size of a biomarker-driven phase III trial / バイオマーカーを用いた第三相試験における最適な試験デザイン及び被験者数の決定基準

Takazawa, Akira 25 May 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医科学) / 甲第22647号 / 医科博第110号 / 新制||医科||7(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 佐藤 俊哉, 教授 川上 浩司, 教授 福原 俊一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
24

Response Inhibition to High Calorie Food Cues Among Adolescents Following Active and Sedentary Video Game Play Using a Go/No-Go Task: A Randomized Crossover Study

Smith, Joshua L 01 December 2017 (has links)
Sedentary behaviors, such as leisure time computer use and sedentary video games, are significant barriers to regular physical activity and contribute to high rates of overweight and obesity among adolescents. Sedentary screen time can adversely affect food intake and food selection. Active video games may be a promising way of increasing daily physical activity levels among adolescents. Active video games may help modulate response inhibition and food intake. PURPOSE: Compare the effects of an acute bout of active and sedentary video gaming on N2 amplitudes (while viewing high calorie and low calorie images), Stroop Color Word Test (Stroop test) performance and ad libitum eating. METHODS: We used a within-subjects randomized crossover design with counterbalanced treatment conditions was used among 65 participants (31 girls, 34 boys; age = 13.5 ± 1.1 year; height = 161.4 ± 10.2 cm; weight = 52.5 ± 12.3 kg; BMI = 19.9 ± 3.3 kg·m2). Participants completed 2 separate video gaming sessions, 7 days apart, while energy expenditure during sedentary and active video game play was measured using the K4b2 portable metabolic system. The K4b2 system provided metabolic equivalents (METs) which are used as a measure of energy cost of physical activity. After either 60 minutes of active or sedentary video game play, participants completed a go/no-go task while viewing high calorie and low calorie images while electroencephalogram (EEG) data were collected. N2 event related potential (ERP) amplitudes were measured during the viewing task. Participants also completed a Stroop task to measure response inhibition. Finally, participants were given high calorie and low calorie snacks to consume ad libitum. We used a repeated measures ANOVA was used to measure main and interaction effects for N2 ERP amplitudes within subjects. RESULTS: Active video game play relative to sedentary video games significantly increased METs (F = 543.1, p ‰¤ 0.0001) from 1.7 ± 0.35 to 5.0 ± 1.2 METs. A significant gender-by-condition interaction (F = 7.03, p ‰¤ 0.009) was observed for energy expenditure with boys (5.4 ± 1.1 METs) expending more energy during the active video game than girls (4.5 ± 1.1 METs). No significant differences were observed for the N2 component (F = 0.50, p = 0.48) between video game conditions nor between genders (F = 1.85, p = 0.17). There were no significant differences (F = 3.10, p = 0.08) in the total number of calories consumed between the 2 video gaming conditions. Results from the Stroop task showed no significant differences for word naming (F = 0.45, p = 0.49), congruent condition (F = 0.43, p = 0.52) and incongruent condition (F = 0.14, p = 0.71) between the active and sedentary video games. CONCLUSION: Sixty minutes of active video gaming increases energy expenditure to a moderate intensity level but does not alter behavioral response or response inhibition to high calorie or low calorie foods.
25

Response Inhibition to High Calorie Food Cues Among Adolescents Following Active and Sedentary Video Game Play Using a Go/No-Go Task: A Randomized Crossover Study

Smith, Joshua L 01 December 2017 (has links)
Sedentary behaviors, such as leisure time computer use and sedentary video games, are significant barriers to regular physical activity and contribute to high rates of overweight and obesity among adolescents. Sedentary screen time can adversely affect food intake and food selection. Active video games may be a promising way of increasing daily physical activity levels among adolescents. Active video games may help modulate response inhibition and food intake. PURPOSE: Compare the effects of an acute bout of active and sedentary video gaming on N2 amplitudes (while viewing high calorie and low calorie images), Stroop Color Word Test (Stroop test) performance and ad libitum eating. METHODS: We used a within-subjects randomized crossover design with counterbalanced treatment conditions was used among 65 participants (31 girls, 34 boys; age = 13.5 ± 1.1 year; height = 161.4 ± 10.2 cm; weight = 52.5 ± 12.3 kg; BMI = 19.9 ± 3.3 kg·m2). Participants completed 2 separate video gaming sessions, 7 days apart, while energy expenditure during sedentary and active video game play was measured using the K4b2 portable metabolic system. The K4b2 system provided metabolic equivalents (METs) which are used as a measure of energy cost of physical activity. After either 60 minutes of active or sedentary video game play, participants completed a go/no-go task while viewing high calorie and low calorie images while electroencephalogram (EEG) data were collected. N2 event related potential (ERP) amplitudes were measured during the viewing task. Participants also completed a Stroop task to measure response inhibition. Finally, participants were given high calorie and low calorie snacks to consume ad libitum. We used a repeated measures ANOVA was used to measure main and interaction effects for N2 ERP amplitudes within subjects. RESULTS: Active video game play relative to sedentary video games significantly increased METs (F = 543.1, p ≤ 0.0001) from 1.7 ± 0.35 to 5.0 ± 1.2 METs. A significant gender-by-condition interaction (F = 7.03, p ≤ 0.009) was observed for energy expenditure with boys (5.4 ± 1.1 METs) expending more energy during the active video game than girls (4.5 ± 1.1 METs). No significant differences were observed for the N2 component (F = 0.50, p = 0.48) between video game conditions nor between genders (F = 1.85, p = 0.17). There were no significant differences (F = 3.10, p = 0.08) in the total number of calories consumed between the 2 video gaming conditions. Results from the Stroop task showed no significant differences for word naming (F = 0.45, p = 0.49), congruent condition (F = 0.43, p = 0.52) and incongruent condition (F = 0.14, p = 0.71) between the active and sedentary video games. CONCLUSION: Sixty minutes of active video gaming increases energy expenditure to a moderate intensity level but does not alter behavioral response or response inhibition to high calorie or low calorie foods.
26

The Effects of a Three-Hour, After School Bout of Sedentary vs Active Behavior on Reward and Cognitive Control Activation in 8- to 9-Year-Old Children: A Randomized Crossover Study

White, Mary Linn 01 April 2018 (has links)
PURPOSE: To compare the effects of after-school sedentary versus active play on activation in the reward and cognitive control regions of the brain to pictures of high- and low-calorie foods. METHODS: 32 children (12 girls, 20 boys; age 8.7 ± 0.5 years; height 137.9 ± 6.9 cm; weight 32.4 ± 6.2 kg) participated in a randomized crossover study with counterbalanced treatment conditions. Conditions took place on separate days after school and included three hours of active or sedentary play. After each condition, neural activation in reward and cognitive control regions of the brain were assessed using functional magnetic resonance imaging (fMRI) while participants completed a go/no-go task involving pictures of high- and low-calorie foods. General response inhibition was measured by the Stroop task. Hunger was measured upon arrival to the testing facility and just prior to fMRI scans. Mixed effects models were used to evaluate main and interaction effects. RESULTS: Significant stimulus by condition interactions were found in the right superior parietal cortex, right postcentral gyrus and accumbens area (p <<> 0.05). High- versus low-calorie pictures of food elicited significantly different activation bilaterally in the orbitofrontal cortex (p <<> 0.01). Stroop task performance diminished significantly following the sedentary condition compared to the active condition (F = 6.79, p <<> 0.01). Subjective feelings of hunger were not different between conditions at any point. CONCLUSION: Sedentary behavior significantly decreased response inhibition and brain activation to pictures of high-calorie foods in areas of the brain important to the modulation of food intake. Decreased attention, reward, and response inhibition, following sedentary behavior, may contribute to disinhibited eating that can lead to overweight and obesity.
27

Predicting Reaction Time from Temporal Performance Indicators on a Go/No-Go Task in Children with Attention Deficit Hyperactivity Disorder

Hwang, Michelle 17 April 2009 (has links)
No description available.
28

Controle contextual com o procedimento go/no-go com estímulos compostos / Contextual control with the go/no-go procedure with compound stimuli

Modenesi, Rafael Diego 19 April 2013 (has links)
O Controle Contextual é descrito a partir de (a) uma contingência de cinco termos (Sx-Sc-Sd- R-Sr) em que o estímulo contextual (Sx) exerce controle condicional sobre as discriminações condicionais e (b) permite que um estímulo participe de mais de uma classe de equivalência sem que haja a fusão das classes. O matching-to-sample é o procedimento mais utilizado para investigar o controle contextual. O objetivo deste estudo foi avaliar se o procedimento go/nogo com estímulos compostos, no qual não é possível identificar as funções condicional e discriminativa, produziria classes de equivalência que compartilham estímulos. Se estas classes fossem produzidas, apenas uma parte da definição de controle contextual (b) seria atestada. Seis universitários realizaram uma tarefa nas fases de treino na qual respostas aos compostos A1C1, A2C2, B1D1, B2D2, X1Y1, X2Y2, X1A1B1, X1A2B2, X2A1B2, X2A2B1 eram seguidas, intermitentemente, por 10 pontos e respostas aos compostos A1C2, A2C1, B1D2, B2D1, X1Y2, X2Y1, X1A1B2, X1A2B1, X2A1B1, X2A2B2 não eram seguidas de consequências. Os estímulos eram formas abstratas. Para se atestar o estabelecimento do controle contextual, os participantes deveriam responder aos compostos Y1C1D1, Y1C2D2, Y2C1D2, Y2C2D1 e não deveriam responder aos compostos Y1C1D2, Y1C2D1, Y2C1D1, Y2C2D2. Este padrão de respostas indicaria a formação de quatro classes de equivalência que compartilham estímulos: X1A1B1Y1C1D1, X1A2B2Y1C2D2, X2A1B2Y2C1D2, X2A2B1Y2C2D1. Quatro dos seis participantes apresentaram desempenhos indicando que é possível estabelecer o controle contextual a partir do procedimento go/no-go com estímulos compostos, sem especificar diferentes funções (e.g., discriminativa, condicional e contextual) para os estímulos envolvidos nestas discriminações. Em função desses resultados, parte (a) da definição de controle contextual mais recorrentemente empregada pode ser questionada / Contextual control is described from (a) a five-term contingency in which the contextual stimulus (Sx) exerts conditional control over conditional discriminations (Sctx Sc Sd R Sr) and (b) allows one stimulus to participate in more than one equivalence class, without merging them into one. Matching-to-sample is the mostly employed procedure to investigate the contextual control. The presented study aimed to evaluate whether a go/no-go procedure that present stimuli in the same manner, without specifying any different stimuli functions, would produce equivalence classes that share stimuli. If equivalence classes could be established with this procedure, only one part of contextual control definition (b) would be met. Six undergraduate were submitted to a task in Training Phase in which responses to A1C1, A2C2, B1D1, B2D2, X1Y1, X2Y2, X1A1B1, X1A2B2, X2A1B2, X2A2B1 compound stimuli were intermittently followed by 10 points, and responses to A1C2, A2C1, B1D2, B2D1, X1Y2, X2Y1, X1A1B2, X1A2B1, X2A1B1, X2A2B2 were not. Two or three abstract forms composed compound stimuli. In Phase III, to certify the establishment of contextual control participants should respond to Y1C1D1, Y1C2D2, Y2C1D2, Y2C2D1 compounds and did not respond to Y1C1D2, Y1C2D1, Y2C1D1, Y2C2D2 compounds. This pattern of responses also indicates the formation of four equivalence classes: X1A1B1Y1C1D1, X1A2B2Y1C2D2, X2A1B2Y2C1D2, X2A2B1Y2C2D1. Four of six participants showed the establishment of contextual control using a go/no-go procedure that do not specify any specific functions for the stimuli. These results indicate that part (a) of the contextual control definition currently used can be questioned
29

美沙冬使用者抑制缺損初探 / Inhibitory deficits of methadone users

郭綺苑, Kuo,Chi Yuan Unknown Date (has links)
本研究的主要目的在於探討美沙冬的使用者是否具有抑制控制能力缺損、對海洛因相關刺激是否具有注意力偏誤,以及是否有彈性認知轉換能力上的問題。 研究使用的是Noel等人(2005,2007)發展出來的Go/No-Go作業,並使用海洛因圖片與中性圖片為作業刺激,分別測量受試者在作業中的反應正確率、反應遺漏數、反應犯錯數、平均反應時間、決定偏誤與區辨度,並且使用依賴嚴重度量表,以了解受試者對海洛因的依賴嚴重度與Go/No-Go作業各指標之間的相關。   美沙冬組樣本選取自八里療養院土城門診部之接受美沙冬治療者,共17人,經由網路招募之健康控制組十九人,受試者一共三十六人。共變數分析之結果顯示在Go/No-Go作業的正確率、遺漏數、區辨度和決定偏誤等指標上,發現組別與情境轉換之交互作用,顯示使用美沙冬之受試者具有彈性認知能力上的缺損,因此在有轉換的區段之中,無法快速地適應新的作答規則。此外,Go/No-Go作業結果未發現美沙冬使用者之抑制缺損與對海洛因相關圖片之注意力偏誤之現象。   依賴嚴重度與Go/No-Go作業的指標相關研究則發現,其依賴嚴重度越高,其在非轉換情境中對海洛圖片的犯錯數越低、決定偏誤越高,顯示美沙冬使用者似乎在沒有情境轉換的區段中,會將其注意力資源分配在海洛因圖片上,忽略非海洛因圖片,顯示其注意力較具選擇性。 / The goal of this study is to explore the inhibitory deficits、attentional bias towards heroin-related cues and cognition flexibility of current methadone users. The Go/No-go task used here was previously developed by Noel et al. (2005, 2007). Heroin-related pictures and neural pictures were presented as targets or non-targets. Accuracy rate、omission、commission、average reaction time、decision bias(C) and discrimination (d’) were being measured individually. The relation between the severity of heroin dependence and task performance was also investigated. The 17 subjects in methadone group were currently methadone maintenance treatment patients from Bali psychiatric center, and the 19 control group subjects without a drug using history were recruited by internet advertisement. The covariance analysis revealed interactions of group and shift/non-shift condition on accuracy rate、omission、decision bias(C) and discrimination (d’), indicating a cognitive flexibility deficits in methadone users. They had difficulty adapting to new rules in shifting conditions. No inhibitory deficits or attentional bias were found so far in this study. The relation between heroin dependence and Go/No-go task performance revealed that the more dependent the methadone subjects were, the less commission errors they made, the higher decision bias score they got towards heroin pictures in non-shifting conditions. It seemed that the methadone users were prone to allocate more attention resource to heroin-related pictures in non-shifting conditions, suggesting a more selective attention process.
30

Controle contextual com o procedimento go/no-go com estímulos compostos / Contextual control with the go/no-go procedure with compound stimuli

Rafael Diego Modenesi 19 April 2013 (has links)
O Controle Contextual é descrito a partir de (a) uma contingência de cinco termos (Sx-Sc-Sd- R-Sr) em que o estímulo contextual (Sx) exerce controle condicional sobre as discriminações condicionais e (b) permite que um estímulo participe de mais de uma classe de equivalência sem que haja a fusão das classes. O matching-to-sample é o procedimento mais utilizado para investigar o controle contextual. O objetivo deste estudo foi avaliar se o procedimento go/nogo com estímulos compostos, no qual não é possível identificar as funções condicional e discriminativa, produziria classes de equivalência que compartilham estímulos. Se estas classes fossem produzidas, apenas uma parte da definição de controle contextual (b) seria atestada. Seis universitários realizaram uma tarefa nas fases de treino na qual respostas aos compostos A1C1, A2C2, B1D1, B2D2, X1Y1, X2Y2, X1A1B1, X1A2B2, X2A1B2, X2A2B1 eram seguidas, intermitentemente, por 10 pontos e respostas aos compostos A1C2, A2C1, B1D2, B2D1, X1Y2, X2Y1, X1A1B2, X1A2B1, X2A1B1, X2A2B2 não eram seguidas de consequências. Os estímulos eram formas abstratas. Para se atestar o estabelecimento do controle contextual, os participantes deveriam responder aos compostos Y1C1D1, Y1C2D2, Y2C1D2, Y2C2D1 e não deveriam responder aos compostos Y1C1D2, Y1C2D1, Y2C1D1, Y2C2D2. Este padrão de respostas indicaria a formação de quatro classes de equivalência que compartilham estímulos: X1A1B1Y1C1D1, X1A2B2Y1C2D2, X2A1B2Y2C1D2, X2A2B1Y2C2D1. Quatro dos seis participantes apresentaram desempenhos indicando que é possível estabelecer o controle contextual a partir do procedimento go/no-go com estímulos compostos, sem especificar diferentes funções (e.g., discriminativa, condicional e contextual) para os estímulos envolvidos nestas discriminações. Em função desses resultados, parte (a) da definição de controle contextual mais recorrentemente empregada pode ser questionada / Contextual control is described from (a) a five-term contingency in which the contextual stimulus (Sx) exerts conditional control over conditional discriminations (Sctx Sc Sd R Sr) and (b) allows one stimulus to participate in more than one equivalence class, without merging them into one. Matching-to-sample is the mostly employed procedure to investigate the contextual control. The presented study aimed to evaluate whether a go/no-go procedure that present stimuli in the same manner, without specifying any different stimuli functions, would produce equivalence classes that share stimuli. If equivalence classes could be established with this procedure, only one part of contextual control definition (b) would be met. Six undergraduate were submitted to a task in Training Phase in which responses to A1C1, A2C2, B1D1, B2D2, X1Y1, X2Y2, X1A1B1, X1A2B2, X2A1B2, X2A2B1 compound stimuli were intermittently followed by 10 points, and responses to A1C2, A2C1, B1D2, B2D1, X1Y2, X2Y1, X1A1B2, X1A2B1, X2A1B1, X2A2B2 were not. Two or three abstract forms composed compound stimuli. In Phase III, to certify the establishment of contextual control participants should respond to Y1C1D1, Y1C2D2, Y2C1D2, Y2C2D1 compounds and did not respond to Y1C1D2, Y1C2D1, Y2C1D1, Y2C2D2 compounds. This pattern of responses also indicates the formation of four equivalence classes: X1A1B1Y1C1D1, X1A2B2Y1C2D2, X2A1B2Y2C1D2, X2A2B1Y2C2D1. Four of six participants showed the establishment of contextual control using a go/no-go procedure that do not specify any specific functions for the stimuli. These results indicate that part (a) of the contextual control definition currently used can be questioned

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