Chronotype describes the daily rhythm of an individual’s performance capability as it changes through the day. It is defined using the Horne-Östberg Morningness-Eveningness Questionnaire (MEQ) which assesses time-of-day preference; or the Munich ChronoType Questionnaire (MCTQ) which indicates sleep timing parameters. My hypothesis was that chronotype predominantly reflects an individual’s perceived daily rhythm in executive function. We tested this by comparing MEQ and MCTQ with the University of Toronto Inventory of Morningness and Eveningness (UTIME) Questionnaire which examines performance on scenarios requiring cognitive, physical, and/or emotional responses. Highest correlations were found between MEQ and UTIME tasks with high executive demand. The same UTIME tasks were also correlated with MCTQ (mid-sleep, free days), although the correlations were consistently lower than UTIME versus MEQ. Correlations among UTIME tasks and MCTQ (mid-sleep, workdays) were not linked to executive demand. Chronotype appears to reflect the perception of peak executive ability independently of sleep pattern.

Background: The current study investigated the efficacy of a novel virtual reality-cognitive rehabilitation (VR-CR) intervention to improve contextual processing of objects in children with autism. Contextual processing is a cognitive ability thought to underlie the social and communication deficits of autism. Previous research supports that children with autism show deficits in contextual processing, as well as deficits in its basic component abilities: abstraction and cognitive flexibility. Methods: Four children with autism participated in a multiple baseline single-subject study. The children were taught how to see objects in context by reinforcing attention to pivotal contextual information. One-on-one teaching sessions occurred three times per week for approximately two weeks. Results: All children demonstrated significant improvements in contextual processing and cognitive flexibility. Mixed results were found on the control test. Changes in context-related behaviours were reported. Conclusions: Further studies using virtual reality to target specific cognitive impairments in children with autism are warranted.

Chronotype describes the daily rhythm of an individual’s performance capability as it changes through the day. It is defined using the Horne-Östberg Morningness-Eveningness Questionnaire (MEQ) which assesses time-of-day preference; or the Munich ChronoType Questionnaire (MCTQ) which indicates sleep timing parameters. My hypothesis was that chronotype predominantly reflects an individual’s perceived daily rhythm in executive function. We tested this by comparing MEQ and MCTQ with the University of Toronto Inventory of Morningness and Eveningness (UTIME) Questionnaire which examines performance on scenarios requiring cognitive, physical, and/or emotional responses. Highest correlations were found between MEQ and UTIME tasks with high executive demand. The same UTIME tasks were also correlated with MCTQ (mid-sleep, free days), although the correlations were consistently lower than UTIME versus MEQ. Correlations among UTIME tasks and MCTQ (mid-sleep, workdays) were not linked to executive demand. Chronotype appears to reflect the perception of peak executive ability independently of sleep pattern.

The purpose of the study was to investigate whether sleep-disordered breathing (SDB) impairs executive functioning in children. Additionally, the study sought to identify the executive functions at risk in SDB and the contribution of daytime sleepiness. SDB represents a spectrum of upper airway conditions that can be mild, such as snoring, or severe, such as obstructive sleep apnea (OSA). Children with these problems may present with excessive sleepiness, failure to thrive, and a variety of cognitive and behavioral dysfunctions including impaired executive functioning. Beebe and Gozal (2002) developed a theoretical model to explain the impact of sleepiness and hypoxia on executive functioning. This model provided a framework to examine links between the medical disorder and the neuropsychological consequences. Twenty-seven children with suspected SDB were tested with polysomnography (PSG) and a neuropsychological battery. Parents completed subjective measures of cognitive function and sleep symptoms. The children were ages 8 to 18 and had no congenital or acquired brain damage. They were matched for age and gender with 21 healthy controls. The executive function protocol included subtests from the Delis-Kaplan Executive Function System (D-KEFS), the digit span subtest from the Wechsler Intelligence Scale for Children (WISC-IV), the Tower of London-II-Drexel University (TOL-II), the Behavioral Rating Inventory of Executive Functioning (BRIEF), and the Conners’ Continuous Performance Test (CPT-II). Statistical analysis was performed using 2 statistical software packages, SAS and NCSS. Regression analysis was used to evaluate all variables. Due to significant group differences in socio-economic status (SES), SES was included as a covariate, along with IQ. No group differences in IQ were found. Significantly less robust executive function in children with SDB was identified in the domains of cognitive flexibility and impulsivity. Additionally, poorer executive planning and overall inattentiveness was also associated with SDB. Level of significance was set at 0.05 and trends (0.05 < p < 0.10) were acknowledged. Other areas of executive function, including working memory, behavioral and emotional inhibition, and processing speed were not associated with SDB. Moreover, academic functioning was significantly lower in children with SDB, although the differences can be shared equally with SDB, SES and IQ.

Because theory of mind (ToM; Samson, 2009) and executive function (EF; Meltzer, 2010) are important skill domains for children’s academic and social success in school, researchers have focused on evaluating the impact of interventions designed to enhance the development of these skills (e.g., Peskin & Astington, 2004; Dowsett & Livesey, 2000). Using an experimental design, the current study evaluated the effectiveness of the Georgia Wolftrap (GWT) program, a drama-based language intervention, at improving ToM and EF in a sample of kindergarten students from low socioeconomic (SES) backgrounds. Researchers (Cole & Mitchell, 1998; Noble, Norman, & Farah, 2005) have indicated that low SES is associated with underdeveloped ToM and EF. Thirteen lessons designed to enhance children’s understanding and use of symbols by exploring literature through imaginative role-play were implemented in place of the regular language arts curriculum. This intervention was hypothesized to engender growth in ToM because it incorporates elements found to be associated with ToM development, such as experience with language (e.g., Jenkins & Astington, 1996), mental state talk (e.g., Adrian, Clemente, & Villanueva, 2007), and pretend play (e.g., Cutting & Dunn, 2006). The impact on EF development, particularly inhibition and attentional control, was expected to be caused by children’s participation in intervention activities that require sustained, active engagement and use of motor and cognitive self-control. Consistent with research describing early childhood as a period of dramatic growth in ToM and EF (e.g., Wellman, Cross, & Watson, 2001), the results of paired-sample t tests indicated that the intervention (n = 41) and control groups (n = 42) demonstrated significant improvement in ToM, inhibition, and attentional control from pre-test to post-test. Despite a trend for the intervention group to demonstrate stronger performance, analyses of covariance (ANCOVAs) indicated that, after controlling for pre-test scores, there were no significant differences in post-test scores between the intervention and control groups. Possible explanations for the lack of significant differences between the intervention and control groups are discussed. Implications for future research are also suggested.

Parents raising children with Attention-deficit/hyperactivity disorder (ADHD) experience high levels of parenting stress, especially when ADHD is accompanied by comorbid Oppositional Defiant Disorder (ADHD/ODD). Children with ADHD experience difficulties with their executive functions in such areas as inhibition control, working memory, and emotional regulation. Despite evidence linking ADHD with parenting stress, and ADHD with executive function difficulties (EFDs), there is little research exploring whether EFDs within an ADHD population are associated with parenting stress. This dissertation’s main objective is to determine whether parent-reported and teacher-reported childhood EFDs are associated with elevated levels of parenting stress. A secondary data analysis was completed on a cross-section of parent and teacher completed psychiatric assessment measures for children (n=243) diagnosed with ADHD. Measures included the Behavior Rating Inventory of Executive Function, the Conners’ Parent Rating Scale and the Parenting Stress Index, Long Form. A number of important findings were produced; key of which was the finding that a strong association exists between parent-reported EFDs and Child Domain parenting stress. Consistent with prior ADHD research, difficulties with emotional control and inhibition were found to be potent predictors of Child Domain parenting stress. To a lesser degree, children’s difficulties with initiation and self-monitoring were associated with Child Domain parenting stress, suggesting that daily hassles pose challenges for parents, especially when the child attends a new school. Also important was the finding that parent-reported oppositionality partially mediated the relationship between EFDs with emotional control, inhibition and shift, and Child Domain parenting stress. Despite teachers’ reports that children displayed more severe behaviours than were reported by parents, teacher-reported EFDs were not significantly associated with Child Domain parenting stress, with a few exceptions. Although not a well-explored concept within the literature on ADHD and parenting stress, parental acceptance of the child emerged as source of Child Domain parenting stress and a potential focus for assessment and treatment. Findings from the current study suggest that early identification and intervention with emotional control difficulties and ODD are vital due to their strong association with clinically significant levels of Child Domain parenting stress.

Parents raising children with Attention-deficit/hyperactivity disorder (ADHD) experience high levels of parenting stress, especially when ADHD is accompanied by comorbid Oppositional Defiant Disorder (ADHD/ODD). Children with ADHD experience difficulties with their executive functions in such areas as inhibition control, working memory, and emotional regulation. Despite evidence linking ADHD with parenting stress, and ADHD with executive function difficulties (EFDs), there is little research exploring whether EFDs within an ADHD population are associated with parenting stress. This dissertation’s main objective is to determine whether parent-reported and teacher-reported childhood EFDs are associated with elevated levels of parenting stress. A secondary data analysis was completed on a cross-section of parent and teacher completed psychiatric assessment measures for children (n=243) diagnosed with ADHD. Measures included the Behavior Rating Inventory of Executive Function, the Conners’ Parent Rating Scale and the Parenting Stress Index, Long Form. A number of important findings were produced; key of which was the finding that a strong association exists between parent-reported EFDs and Child Domain parenting stress. Consistent with prior ADHD research, difficulties with emotional control and inhibition were found to be potent predictors of Child Domain parenting stress. To a lesser degree, children’s difficulties with initiation and self-monitoring were associated with Child Domain parenting stress, suggesting that daily hassles pose challenges for parents, especially when the child attends a new school. Also important was the finding that parent-reported oppositionality partially mediated the relationship between EFDs with emotional control, inhibition and shift, and Child Domain parenting stress. Despite teachers’ reports that children displayed more severe behaviours than were reported by parents, teacher-reported EFDs were not significantly associated with Child Domain parenting stress, with a few exceptions. Although not a well-explored concept within the literature on ADHD and parenting stress, parental acceptance of the child emerged as source of Child Domain parenting stress and a potential focus for assessment and treatment. Findings from the current study suggest that early identification and intervention with emotional control difficulties and ODD are vital due to their strong association with clinically significant levels of Child Domain parenting stress.

An age-related decline in cerebral blood flow (CBF) is widely acknowledged. However, uncertainty exists as to whether this reduction is the result of a reduced metabolic demand (cerebral atrophy) or an impaired delivery system (cerebrovascular disease). The purpose of these experiments was to examine the relationship of CBF and dynamic cerebrovascular regulation with changes in common carotid intima-media thickness (cIMT), brachial-ankle pulse wave velocity (baPWV) and common carotid distensibility. Additionally, we took an exploratory view into the effect of vascular aging and CBF reduction on brain function, as expressed through the performance of motor and cognitive tasks. An important finding in elderly participants was that seated anterior CBF declined as a function of arterial stiffness, independently of age. Linear regression analysis developed a model that predicts CBF drops 22 ml/min (95% confidence interval (CI): 6, 38) for each 100 cm/s increase in baPWV and 8 ml/min (95% CI: 1, 15) for each additional year in age. The effect of baPWV appears to be mediated through an increase in cerebrovascular resistance (r2 = 0.84, p < 0.0001). Additionally, CBF showed postural dependency and the volume of the drop in CBF between supine and seated positions was greatest in elderly participants (YOUNG: 65 ± 81 ml/min; ELDERLY: 155 ± 119 ml/min; p = 0.001). Despite this negative impact of vascular aging on steady state flow, dynamic regulation does not appear to be affected. Cerebrovascular responses to an acute drop in blood pressure or to activation of the motor cortex were not attenuated in the elderly participants. Finally, seated CBF had modest directionally relevant relationships with perceptuo-motor and complex sequencing processes; while cIMT appeared to influence performance on initiation and inhibition tasks.

An age-related decline in cerebral blood flow (CBF) is widely acknowledged. However, uncertainty exists as to whether this reduction is the result of a reduced metabolic demand (cerebral atrophy) or an impaired delivery system (cerebrovascular disease). The purpose of these experiments was to examine the relationship of CBF and dynamic cerebrovascular regulation with changes in common carotid intima-media thickness (cIMT), brachial-ankle pulse wave velocity (baPWV) and common carotid distensibility. Additionally, we took an exploratory view into the effect of vascular aging and CBF reduction on brain function, as expressed through the performance of motor and cognitive tasks. An important finding in elderly participants was that seated anterior CBF declined as a function of arterial stiffness, independently of age. Linear regression analysis developed a model that predicts CBF drops 22 ml/min (95% confidence interval (CI): 6, 38) for each 100 cm/s increase in baPWV and 8 ml/min (95% CI: 1, 15) for each additional year in age. The effect of baPWV appears to be mediated through an increase in cerebrovascular resistance (r2 = 0.84, p < 0.0001). Additionally, CBF showed postural dependency and the volume of the drop in CBF between supine and seated positions was greatest in elderly participants (YOUNG: 65 ± 81 ml/min; ELDERLY: 155 ± 119 ml/min; p = 0.001). Despite this negative impact of vascular aging on steady state flow, dynamic regulation does not appear to be affected. Cerebrovascular responses to an acute drop in blood pressure or to activation of the motor cortex were not attenuated in the elderly participants. Finally, seated CBF had modest directionally relevant relationships with perceptuo-motor and complex sequencing processes; while cIMT appeared to influence performance on initiation and inhibition tasks.

Individuals with Asperger syndrome (AS), an autism spectrum disorder, are characterized by average to superior intelligence while at the same time experiencing severe and pervasive deficits in social interaction. While many individuals with AS report that they keenly desire social relationships, the combination of repeated social failures and intelligence sufficient to appreciate these difficulties increases the risk for developing depression, anxiety, and other mental health concerns (Tantam, 1998; 2000). <p>Emotional intelligence (EI) is a construct that offers potential to understand individual emotional and social characteristics. The broad purpose of the two studies in this project was to examine ability and trait approaches to EI to understand if EI offers enriched understanding of social outcomes in AS. Further, this study explored EI, executive functions (EF), and theory of mind (ToM) to understand whether EI singularly or in combination with other theoretical explanations best accounts for social outcomes in individuals with AS. <p>The participants in this study were 25 young adults (aged 16-21) diagnosed with AS in Alberta and Manitoba. In study 1, trends and differences between AS and normative groups were examined. Further, correlation and multiple regression were employed to explore relationships amongst variables. Results indicated that trait EI was impaired for individuals with AS; however ability EI was intact. Regression analyses revealed that trait and ability EI together predicted 57% the variance for self-reported interpersonal skills and 31% of the variance for parent-reported social skills. Trait EI alone predicted 19% of the variance for self-reported social stress. <p>In study 2, EI, EF, and ToM were explored as predictors of social outcomes. Low correlations between EF and outcome variables precluded further analysis with this particular set of variables. Multiple regression procedures revealed that together ToM and trait EI predicted 33 % of the variance for self-reported Social Stress. The findings suggest that including ToM and EI measures in assessment protocols for individuals with AS provides important information to inform interventions.