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>Magister Scientiae - MSc / Introduction: Sustained attention is known to be dysfunctional in psychotic disorders. Sustained attention is the ability to remain focused on a specific time-locked stimulus within a task. We aimed to determine whether there are specific group differences between CON and three psychotic disorders: SCZ, MPD and BPD, then to determine differences between these psychotic disorders. This included differences in behavioural performance and prominent electrophysiological event-related potential (ERP) wave components during cueing and target processing of a visual sustained attention task. Further we aimed to characterize ERP waveform component relationships across and within these groups for demographics, substance use, behavioural performance, and clinical variables, the last limited to the psychotic groups. Lastly, we investigated the effects of prescribed medications on ERP wave components within the psychotic groups. Methodology: 103 participants (29 schizophrenia (SCZ), 28 bipolar disorder with a history of psychosis (BPD), 21 methamphetamine-induced psychotic disorder (MPD), and 30 controls (CON)) underwent electroencephalography (EEG) record while completing a visual continuous performance task. Participants were presented with 60 trials with three consecutive S’s, the presentation of the third S required a behavioural response. Prominent ERP waveform components were extracted from cues and target stimulus. Group differences were determined by ANOVA with Bonferroni post-hoc correction or multivariate Kruskal-Wallis test dependent on data distribution. Relationships between ERP wave components were determined appropriate with Spearman’s Rank order correlation analyses.

Sabe-se que diversas regiões do cérebro humano trabalham em sincronia, mesmo anatomicamente separadas, sugerindo conexões funcionais e estruturais. Dessa forma, nosso cérebro pode ser considerado uma rede que pode ser estudada para diferenças entre indivíduos e entre tarefas, em que os nodos podem ser diferentes regiões e as arestas podem ser medidas de conectividade funcional entre séries temporais de um sinal de ressonância magnética de cada região. Neste estudo, propomos analisar como conectividade funcional e parâmetros de rede cerebral se relacionam com desempenho intelectual e um estado de atenção sustentada. Foram adquiridas imagens de ressonância magnética de 30 indivíduos saudáveis jovens em estado de repouso e de atenção sustentada, a partir delas foram calculadas as conexões funcionais entre 90 regiões cerebrais usando o coeficiente de correlação entre pares de series temporais. Destes sujeitos foram estimados sete índices de inteligência a partir da aplicação do teste WAIS-III. As matrizes de conectividade evidenciariam um comportamento de rede complexa de mundo pequeno para limiares entre 0,2 e 0,5. Não foram encontradas associações entre parâmetros globais das redes ponderadas em estado de repouso e os índices de inteligência. Conectividade funcional e alguns parâmetros de rede locais evidenciaram correlações com pontuações de inteligência, principalmente nas regiões frontal, pré-central, parietal e occipital, giro fusiforme e supramarginal e caudado. Embora o p-valor não-corrigido seja bem pequeno e/ou haja simetria entre hemisférios em alguns resultados, ao ser considerado o efeito de múltiplas comparações para análise inteira não foram encontradas associações estatisticamente significativas, por isso as análises foram corrigidas para cada região (p-valor corrigido pelo FDR<0,05). Ainda assim, possivelmente um aumento do número de sujeitos levaria a resultados mais conclusivos. Não foram encontrados resultados que confirmassem a hipótese de que, para indivíduos normais, haveria uma maior anti-correlação de redes extrínsecas e intrínsecas como um todo para o estado de atenção focada em relação ao estado de repouso. Entretanto, durante o estado de atenção sustentada, foram encontradas algumas diferenças estatisticamente significantes nas conexões locais dentro das redes positivas e negativas à tarefa, evidenciadas por um aumento na magnitude das correlações positivas ou negativas durante a atenção sustentada, além de uma tendência de anti-correlação em conexões entre regiões positivas e negativas à tarefa. / It\'s known that some regions of the human brain work synchronously, even if they are anatomically separated, suggesting functional and structural connections. In this way, our brain can be considered a network that can be studied for individual or task differences and in which nodes can be the different regions and edges can be the measurements of functional connectivity between blood oxygen level-dependent signal time series from each region. In this study, we aim to analyze how functional connectivity and brain network parameters relate to intellectual performance and to sustained attention state. Resonance Magnetic images were acquired in 30 healthy young volunteers in resting and attentional state. The functional connections between 90 brain regions were computed from them using correlation coefficient between pairs of temporal series. Seven intelligence indices were estimated from these subjects through WAIS-III test application and associations between functional connectivity values or brain network parameters were sought. Connectivity matrices evidenced a small-world complex network behavior for thresholds between 0.2 and 0.5. No associations between global parameters using weighted networks were found. Functional connectivity and network parameters have evidenced some correlations with intelligence scores, mainly in frontal, pre-central, parietal, occipital regions, fusiform and supramarginal gyrus and caudate nucleus. Even that the uncorrected p-value was small and/or there was symmetry between hemispheres in several results, statistical significant associations were not found considering multiple comparisons correction for the entire analysis, therefore the analysis were corrected for each region (FDR corrected p-value <0.05). Even, increasing the number of subjects possibly would get more conclusive results. Results corroborant to the initial hypothesis of greater anti-correlation between default mode network and task-positive regions were not found for the sustained attention state. However, during sustained attention state, some statistically significant differences in local connections within task-positive and negative regions were found, evidenced by the increase of the strength of positive and negative correlations, besides of a trend of anti-correlation in connections between task-positive and negative regions.

The present study examined the relation between self-report mindfulness and performance on tasks measuring abilities for three aspects of attention: sustained, selective, and attention switching. Because attention regulation has been described as a core component of mindfulness, and past research suggests that experience with mindfulness meditation is associated with improved attentional skills, the present study predicted that higher self-report mindfulness would be positively related to performance on tasks of attention. Fifty undergraduate students completed self-report mindfulness questionnaires and completed a battery of attention tasks. There was mixed support for the relation between mindfulness scores and sustained attention, such that higher mindfulness scores as measured by the MAAS and CAMS-R were negatively related to target omissions on the CPT-II, but were not related to RT variability on the CPT-II or PASAT performance. Findings are discussed in the context of the measurement of self-report mindfulness, and directions for future research are considered.

Children with Fetal Alcohol Spectrum Disorder (FASD) may suffer numerous cognitive impairments, including significant problems with executive functioning, language, attention, and memory [40]. It is estimated that two to five percent of children born in the U.S. are affected by FASD [34]. It has been shown that training improvements can be made in working memory and attention in children with ADHD [25]. Computerized training with game elements enhances not only motivation but training efficacy of these interventions [38]. This thesis examines the creation of two suites of serious games, Cognitive Carnival and Caribbean Quest, intended to improve working memory aspects of attention with the assistance of a trained psychology interventionist in a therapeutic setting. A game-based approach is chosen to provide motivation to children for sustained cognitive challenges presented by cognitive exercises built into the gameplay. Cognitive Carnival was shown by interventionists to have positive effects in neuropsychological studies of populations of children with epilepsy and FASD [33, 30]. / Graduate

This study investigated executive function and sustained attention in preterm and full-term infants at 8 months after expected date of delivery and at 10-11 months chronological age. Executive function and sustained attention emerge in infancy and continues to develop throughout childhood. Executive function and sustained attention is believed to underlie some learning problems in children at school age. Although numerous studies have reported that the overall development of preterm infants is comparable to that of full-term infants at the same corrected age, it is unclear to what extent the development of specific cognitive abilities is affected by prematurity and/or other factors such as medical complications. As preterm infants have a high rate of learning difficulties, it is possible that factors associated with prematurity specifically affect the development of some regions of the brain associated with the regulation of executive function and sustained attention. Thirty-seven preterm infants without identified disabilities, and 74 due date and gender matched healthy bull-term infants, participated in the present study. The preterm infants were all less that 32 weeks gestation and less that 1500 grams birth weight. The current study aimed to examine the effects of maturation and length of exposure to extrauterine environmental stimuli on the development of executive function and sustained attention, by comparing the development of preterm infants with that of full-term infants at both the same corrected age and the same chronological age. All infants were therefore assessed on executive function and sustained attention tasks at 8 months after the expected date of delivery (when preterm infants were actually 10-11 months chronological age). The full-term infants in the study were then reassessed at an age equivalent to the chronological age of their matched preterm infants at the time of the first assessment. The findings of the study showed that preterm infants performed significantly more poorly than full-term infants at both 8 months after the expected date of delivery and 10-11 months chronological age on all measures of executive function and sustained attention. However the difference between preterm and full-term infants at 8 months after expected date of delivery was much less that at 10-11 months chronological age. The results suggested that the effects of maturation are greater that the effects of exposure to extrauterine environmental stimuli on the development of executive function and sustained attention. However, as the performance of the preterm infants was below that of the term infants at the same corrected age, it was necessary to consider whether other factors associated with preterm birth were contributing to this difference. Confounding factors including cognitive abilities and psychomotor skills on the Bayley Scales of Infant Development, infant temperament, maternal education, family socioeconomic status and maternal psychological wellbeing were examined. Statistical analysis of the effects of these factors on the difference between preterm ad full-term infants found that only psychomotor sills significantly affected the differences between preterm and full-term infants of the same corrected age on executive function measures, although not on sustained attention measures. The differences between preterm and full-term infants of the same corrected age remained even when psychomotor skills were taken into consideration; therefore psychomotor skills were not sufficient to fully explain the differences between preterm and full-term infants in the performance of executive function. Consequently, the preterm infants were divided into two subgroups on the basis of (a) low or high medical risk factors, (b) birth weight of less that 1000g versus 1000-1500g, and (c) gestation age of less that 28 weeks versus 28-32 weeks, in order to assess the effects of these variables on the performance of executive function and sustained attention. Medical risk, lower birth weight and lower gestation age were all found to adversely affect performance on executive function, but did not affect the performance on sustained attention tasks. It is argued that these factors may influence the development of specific areas of the brain which govern executive function, and that as the prefrontal regions are particularly immature they may be especially vulnerable to damage or disruption. The fact that these perinatal factors did not contribute to the difference between preterm and full-term infants' performance on sustained attention tasks. This suggests that the deficits of sustained attention in preterm infants may be associated with birth prematurity per se, and that additional complications may not have any further detrimental effect. The three components of executive function (i.e., working memory, inhibition, and planning) did not correlate with each other when only infants with Bayley psychomotor ability scores greater that 85 were included, suggesting that the components of executive function may be discrete abilities which are governed by different parts of the prefrontal cortex. Sustained attention correlated with planning, supporting the suggestion that it may be a cognitive dimension which overlaps with executive function, depending upon the task requirement. Neither executive functio nor sustained attention correlated with the Bayley mental ability and Bayley psychomotor ability scores when infants with scores of less than 85 were excluded. This suggests that executive function and sustained attention measures are independent of general development.

Sabe-se que diversas regiões do cérebro humano trabalham em sincronia, mesmo anatomicamente separadas, sugerindo conexões funcionais e estruturais. Dessa forma, nosso cérebro pode ser considerado uma rede que pode ser estudada para diferenças entre indivíduos e entre tarefas, em que os nodos podem ser diferentes regiões e as arestas podem ser medidas de conectividade funcional entre séries temporais de um sinal de ressonância magnética de cada região. Neste estudo, propomos analisar como conectividade funcional e parâmetros de rede cerebral se relacionam com desempenho intelectual e um estado de atenção sustentada. Foram adquiridas imagens de ressonância magnética de 30 indivíduos saudáveis jovens em estado de repouso e de atenção sustentada, a partir delas foram calculadas as conexões funcionais entre 90 regiões cerebrais usando o coeficiente de correlação entre pares de series temporais. Destes sujeitos foram estimados sete índices de inteligência a partir da aplicação do teste WAIS-III. As matrizes de conectividade evidenciariam um comportamento de rede complexa de mundo pequeno para limiares entre 0,2 e 0,5. Não foram encontradas associações entre parâmetros globais das redes ponderadas em estado de repouso e os índices de inteligência. Conectividade funcional e alguns parâmetros de rede locais evidenciaram correlações com pontuações de inteligência, principalmente nas regiões frontal, pré-central, parietal e occipital, giro fusiforme e supramarginal e caudado. Embora o p-valor não-corrigido seja bem pequeno e/ou haja simetria entre hemisférios em alguns resultados, ao ser considerado o efeito de múltiplas comparações para análise inteira não foram encontradas associações estatisticamente significativas, por isso as análises foram corrigidas para cada região (p-valor corrigido pelo FDR<0,05). Ainda assim, possivelmente um aumento do número de sujeitos levaria a resultados mais conclusivos. Não foram encontrados resultados que confirmassem a hipótese de que, para indivíduos normais, haveria uma maior anti-correlação de redes extrínsecas e intrínsecas como um todo para o estado de atenção focada em relação ao estado de repouso. Entretanto, durante o estado de atenção sustentada, foram encontradas algumas diferenças estatisticamente significantes nas conexões locais dentro das redes positivas e negativas à tarefa, evidenciadas por um aumento na magnitude das correlações positivas ou negativas durante a atenção sustentada, além de uma tendência de anti-correlação em conexões entre regiões positivas e negativas à tarefa. / It\'s known that some regions of the human brain work synchronously, even if they are anatomically separated, suggesting functional and structural connections. In this way, our brain can be considered a network that can be studied for individual or task differences and in which nodes can be the different regions and edges can be the measurements of functional connectivity between blood oxygen level-dependent signal time series from each region. In this study, we aim to analyze how functional connectivity and brain network parameters relate to intellectual performance and to sustained attention state. Resonance Magnetic images were acquired in 30 healthy young volunteers in resting and attentional state. The functional connections between 90 brain regions were computed from them using correlation coefficient between pairs of temporal series. Seven intelligence indices were estimated from these subjects through WAIS-III test application and associations between functional connectivity values or brain network parameters were sought. Connectivity matrices evidenced a small-world complex network behavior for thresholds between 0.2 and 0.5. No associations between global parameters using weighted networks were found. Functional connectivity and network parameters have evidenced some correlations with intelligence scores, mainly in frontal, pre-central, parietal, occipital regions, fusiform and supramarginal gyrus and caudate nucleus. Even that the uncorrected p-value was small and/or there was symmetry between hemispheres in several results, statistical significant associations were not found considering multiple comparisons correction for the entire analysis, therefore the analysis were corrected for each region (FDR corrected p-value <0.05). Even, increasing the number of subjects possibly would get more conclusive results. Results corroborant to the initial hypothesis of greater anti-correlation between default mode network and task-positive regions were not found for the sustained attention state. However, during sustained attention state, some statistically significant differences in local connections within task-positive and negative regions were found, evidenced by the increase of the strength of positive and negative correlations, besides of a trend of anti-correlation in connections between task-positive and negative regions.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22885号 / 医博第4679号 / 新制||医||1048(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊佐 正, 教授 古川 壽亮, 教授 高橋 淳 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Research indicates children with disabilities benefit from therapeutic horseback riding (TR). This study examined the impact TR had on attention behaviors of five children with various developmental disabilities in a preschool classroom. Children were observed in the classroom setting twice weekly for 10 weeks on a day they participated in TR services and on a day they did not participate in TR. Single case experiments suggested there was not a significant difference in all but one child’s sustained attention in the classroom on days children received TR services. An independent samples t-test suggested there was no significant difference in scores between riding day (M<./I> = 1.78, SD =.247) and non-riding days (M = 1.76, SD = .262); t(87) = -.481, p = .632 for the group as a whole. Further research should be conducted to determine TR’s effect on behaviors in the classroom.

Uppsatsen syfte var att undersöka effekten av koffeinintag på mental uthållighet. Hypotesen var att koffein skulle förbättra mental uthållighet på ett statistiskt signifikant vis. 34 individer rekryterades genom ett bekvämlighetsurval. SART (Sustained Attention to Response Task) användes för att mäta mental uthållighet före och efter intag av 180 mg koffein. Resultat på SART visade en signifikant minskning i antal fel gjorda, men inte i responstid. Det påvisades även en signifikant korrelation mellan ålder och responstid där äldre individer uppvisade en längre responstid före och efter koffeinintag. De förbättrade resultaten på SART efter koffeinintag är i linje med annan koffeinforskning och studien ger ytterligare stöd till att koffein förbättrar mental uthållighet. Metodologiska brister i form av en eventuell förväntanseffekt, intag av B-vitaminer i samband med koffeinintag, okontrollerade motivationsfaktorer, och eventuellt andra oidentifierade confounding variabler i undersökningen gör att vi inte med fullständig säkerhet kan tillskriva den signifikanta förbättringen i mental uthållighet till enbart koffein. / The purpose of this study was to examine the effects of caffeine on sustained attention. The working hypothesis was that caffeine would increase sustained attention in a significant way. 34 individuals were recruited by way of a convenience sample. SART (Sustained Attention to Response Task) was used to measure sustained attention before and after ingestion of 180 mg of caffeine. Results of SART showed a significant decrease in the number of errors made, but not in response time after caffeine ingestion. The study also showed a significant correlation between age and response time, in which older adults took a longer time to respond before and after caffeine ingestion. The improved results of SART after caffeine ingestion are in line with other caffeine studies and provide further support to the notion that caffeine improves sustained attention. Methodological shortcomings in shape of an eventual expectancy effect, intake of B vitamins in conjunction with caffeine intake, uncontrolled motivational factors and other eventual unidentified confounding variables makes it so that we can't ascribe the significant improvement in sustained attention to only caffeine with absolute certainty.