Executive function (EF) comprises a series of interrelated cognitive and self-regulatory skills which are required in nearly every facet of everyday life, particularly in novel circumstances. EF skills begin developing from birth and continue to grow well into adulthood but are most crucial for children as they are associated with academic and life success as well as mental and physical health. There is now strong evidence that these skills can be trained through targeted intervention in a diverse range of approaches, such as computer games, physical activity, and social play settings. This thesis presents the process of the design and evaluation of an active EF-training game (BrainQuest) for smart-phones, in participation with end-users: a group of 11-12-year-old children from a local Primary School. The design process placed emphasis on creating an engaging user experience, a phenomenon which has eluded many serious games, by building upon motivational game design theory and satisfying end-user requirements. However, in the pursuit of promoting particular executive functions: working memory; inhibitory control; planning and strategizing, the design integrated aspects of a cognitive assessment while also utilizing a range of alternative approaches for training EF, including physical activity and social play. Following an iterative design process which included many single session prototype evaluations, a mixed methods evaluation was undertaken during a 5-week study with twenty-eight 11-12-year-old school children. The study gathered exploratory qualitative and quantitative evidence regarding the game’s potential benefits which was evaluated by triangulating a range of data sources: multi-observer observations notes, interviews with children and teachers, game performance data and logs, and cognitive assessment outcomes. The analysis describes the statistical relationships between game and executive function ability, before exploring user experiences and evidence of cognitive challenge during gameplay through a series of triangulated case studies and general whole-class observations. The analysis presents the game to be engaging and enjoyable throughout the study and, for most children, able to generate a sustainable challenge. Though there were initial difficulties in understanding the complex game rules and technology, the game became increasingly usable and learnable for the target user group and created opportunities for goal setting. It also encouraged feelings of pride and self-confidence as well as facilitating positive social interactions and requiring regulation of emotion, which are considered to be pathways to developing executive functions (Diamond, 2012). There was also promising initial evidence that the game’s variable difficulty level system was able to challenge executive functions: planning and strategizing, working memory, and inhibitory control. Most notably, the game appeared to support improvements in strategizing ability by demanding increasing strategic complexity in response to evolving and increasingly difficult task demands. Supporting BrainQuest’s cognitive challenge, several statistical relationships emerged between executive function ability and game performance measures. However, the game’s ability to significantly improve cognitive outcomes could not yet be concluded. Nevertheless, these findings have implications for both the future design and evaluation practices undertaken by cognitive training researchers. From a design perspective, less credence should be paid to simply gamifying cognitive assessments while greater emphasis should be placed on integration of formal game design and motivational theories. With regards to evaluation, researchers should understand the importance of establishing first whether CTGs can remain engaging over time as well as the feasibility of their challenge to cognitive functions.

This thesis explores the proposal that there is a close link between counterfactual thinking and lying. Although both require the imagination of alternatives to reality, research has yet to establish a direct link. In the first seven studies the relationship between counterfactuals and lies is directly investigated using novel scenario-based and behavioural tasks. In a further four studies we also investigate the role of affect and executive functions as explanatory mechanisms. Results show that individuals with a tendency to think counterfactually are more likely to generate potential lies and to be more successful when lying in front of others (Study 1 and 6). Furthermore, we also show that counterfactual availability influences people’s tendency to come up with lies (Studies 2, and 3) and the extent to which they expect others to lie (Studies 4, and 5). We also find that the saliency of counterfactual alternatives can affect people’s moral standards by motivating them to lie (Study 7). Based on these results we argue that counterfactuals motivate lying by providing information about how things could have been different. We however also investigate alternative explanations. In Studies 8, 9 and 10 we seek to understand whether counterfactually derived affect might also underlie the relationship, but find no such link. Additionally, in Study 11 we investigate the relationship in Parkinson’s disease participants in order to understand if executive function might be an underlying mechanism. We do not find this to be the case and we show that PD patients are able to engage in counterfactual thinking and also lie. The findings in this thesis are the first to provide a direct link between counterfactual thoughts and lies. Overall, we show how counterfactuals can help us mislead others and we reveal that counterfactual thinking is an important cognitive process in deception.

Analogical reasoning is a foundational skill necessary for enabling learners to draw inferences about new experiences, to transfer learning across contexts, and to make abstractions based on relevant information from daily experiences. Linguistic and executive function (EF) skills may support analogical reasoning ability, as both these skill sets have previously been shown to influence other higher-order cognitive abilities, such as perspective taking. Outside influences such as socio-economic status (SES) backgrounds may also influence analogical reasoning, as they have been shown to affect other cognitive processes. At present, current research offers little information about developmental relations among SES, language, EF and analogical learning. The purpose of this dissertation research was to explore the extent to which the provision of relational language facilitates children’s analogical reasoning, and to investigate the influence of SES, executive function and language skills in regard to such facilitation. Results indicate that the use of relational language indeed aids analogical reasoning. SES significantly predicted analogical reasoning, but interestingly, this was so only when relational language was absent. These findings support that relational language plays a key role in scaffolding analogical reasoning, and this support is particularly beneficial to children whose cognitive skills may be influenced by SES.

Research is increasingly attempting to understand the developmental nature of depressive symptomology and its links with executive functioning (EF), repetitive negative thinking (RNT) and stress (e.g., Snyder & Hankin, 2016). Prospective studies are needed to explore the potential mechanisms underlying these associations. This study investigated whether EFs can predict changes in RNT, stress and depressive symptoms during a period of stress. One hundred and two undergraduates completed questionnaires measuring life events, trait and state RNT, depressive and anxious symptoms as well as behavioural EF tasks of cognitive switching and inhibitory control at baseline (Time 1). Follow-up questionnaires of RNT, stress, depression and anxiety were gathered approximately two months later (Time 2), during students’ formal examinations, a period of naturally elevated stress. Findings indicated no association between EF and RNT, depression or anxiety but found that the interaction between high levels of trait RNT and low levels of EF (switching) at baseline was a significant predictor of change in state RNT under stress. Findings are discussed in light of current research attempting to unpick associations between EF, RNT and depression in young adults.

This study aimed to answer whether current research addressing executive function abilities in cochlear implant users was accurately depicting their impairments. Secondly, this study aimed to identify differences in identification of executive function impairments when measured using parent report versus behavioral measures of executive function. Results suggest that children do have executive function impairments in areas of measure nonverbal planning, problem-solving, monitoring, and self-regulation abilities as well as attention to a visually presented array of pictures which has been documented in previous research. However, it is likely that these abilities are modulated by children with cochlear implants' poorer language ability as demonstrated on the PPVT, which seems not to be related to their age of implantation. The behavioral measures and parent report measures identified impairments in the subsets which required a greater language demand and subsequently subsets that were significantly more difficult for CI children.

Executive function (EF) is a central aspect of cognition that undergoes significant changes in early childhood. Changes in EF in early childhood are robustly predictive of academic achievement and general quality of life measures later in adulthood. I develop a dynamic neural field (DNF) model which provides a process-based account of behavior and developmental change in a key task used to probe the early development of executive function--the Dimensional Change Card Sort (DCCS) task. In the DCCS, children must flexibly switch from sorting cards either by shape or color to sorting by the other dimension. Typically, 3-year-olds, but not 5-year-olds, lack the flexibility to do so and perseverate on the first set of rules when instructed to switch. In Study 1, I use the DNF model to integrate behavioral and neural processes by simulating hemodynamics associated with the early emergence of flexible rule-use. I then test predictions of the model using near-infrared spectroscopy. In Study 2, I develop a DCCS that can be used with adults that sheds light on key aspects of the task as they have been revealed with children. Using fMRI, a pattern of behavioral and neural effects shed light on the central processes involved in flexible rule-use. These two studies demonstrate that performance emerges as a property of system-wide interactions and that common neurocognitive effects .can be found between childhood and adulthood.

Data on standardized tests is often used to advocate for the inclusion of music programs in secondary education curriculum. There have been studies that claim to identify a relationship between music participation and higher earned test scores; however, correlation does not necessarily equate to causation. The argument between whether music instruction improves student testing ability or if higher achieving students are attracted to music courses is still prevalent within the music education domain. Executive function represents the processes within the brain that encompass a number of cognitive ability processes used in the transfer of knowledge. These processes are essential to progression and success in education (Caine & Caine, 2006; Chan, et. al., 2008). Research demonstrates that music instruction has the capacity to enhance various executive function processes in young students with previous music instruction and individualized violin training (Bugos, 2010; Ho et al., 2003; Chan et al., 1998). The purpose of this study was to evaluate the effects of secondary music instruction, specifically in the band setting, on executive function processes of processing speeding and working memory. 40 high school students, 20 students who had received previous band instruction and 20 who had not received previous band instruction ages 13 to 18, completed various cognitive and musical assessments to gauge musical ability and cognitive function (measuring attention, working memory, and processing speed). Students from both groups were paired using the Wechsler Abbreviated Intelligence Scale. Analysis of the results demonstrated that students who received prior band instruction demonstrated enhanced processing speed and working memory indices, as well as increased attention abilities.

<p>Deficits in higher order cognitive processes such as inhibitory control and working memory (WM), grouped under the term of executive function (EF), have been shown to constitute one important component of the complex neuropsychology of Attention Deficit Hyperactivity Disorder (ADHD). The aim of the present thesis was to examine EF in relation to ADHD, with primary focus on structure (i.e., dimensions) and developmental change. Rooted in the developmental and dimensional perspectives of ADHD, which propose that the disorder represents the extreme of or quantitative delays in traits that are present throughout the general population, four studies (I-IV) based on non-clinical and clinical samples of children at different developmental levels were conducted.</p><p>Together, the results from Study I-IV suggest that inhibitory control and WM are important components of EF in typically developing children as well as in relation to ADHD symptoms. Of particular interest are the findings from Study II, III, and IV, showing that inhibitory control and WM seem to be of different importance depending on the child’s age. More specifically, the non-clinical and clinical studies suggest that inhibitory control and WM are important in predicting ADHD symptoms, with deficits in inhibitory control primarily being associated with ADHD symptoms for preschool and younger elementary school-aged children, whereas deficits in WM are associated with ADHD symptoms for older elementary school-aged children. </p><p>In conclusion, the results of the present thesis are consistent with Barkley’s (1997) developmental prediction concerning the relation between EF and ADHD, which suggests that impaired inhibitory control is an early developmental precursor to or a factor that “sets the stage” for deficits in more complex EFs such as WM. The home taking message from the present thesis is that age matters not only in the behavioral, but also in the neuropsychological manifestation of ADHD. To our knowledge, these findings are among the first to show that age is an important factor that should be taken into account in future ADHD research, theory, and treatment.</p>

Current theoretical models of ADHD (i.e., Disinhibition Model: Barkley, 1997; Working Memory Model: Rapport et al., 2001) conceptualize ADHD as the disorder of executive function (EF) with some variation in their emphases on particular components of the broadly-defined EF (e.g., working memory vs. inhibition) and in their postulated relationships with ADHD symptoms. Although these models provide systematic accounts of the manifestation of ADHD, they have not been extensively tested from an empirical standpoint. Moreover, despite the fact that ADHD is highly comorbid with other additional conditions such as learning and behavioral problems and EF deficits are found in individuals with these conditions as well as in those with ADHD, current EF models have not specified the developmental relationship between ADHD and its comorbid conditions. This study was: (1) to examine the extent to which two current models of ADHD are supported in a sample of 102 adults; (2) to present an ??integrated?? model by combining two current models of ADHD and linking them to recent research findings on two common comorbid conditions with ADHD (i.e., reading difficulty and substance abuse); and (3) to test and revise such an integrated model in the light of data using a latent variable analysis. Major findings provided a strong support for the Working Memory Model with a lesser degree of support for the Disinhibition Model. Preliminary evidence of working memory as the primary deficit in ADHD was also obtained in the present sample. Finally, the integrated EF model and its revised model (final model) demonstrated a very good fit to the data. These findings suggest that the integrated model provides a unified account of how EF deficits contribute to the manifestation of ADHD symptoms and comorbid conditions with ADHD. Given some limitations (e.g., sample size and scope) of the present study, current findings need to be replicated.

Deficits in higher order cognitive processes such as inhibitory control and working memory (WM), grouped under the term of executive function (EF), have been shown to constitute one important component of the complex neuropsychology of Attention Deficit Hyperactivity Disorder (ADHD). The aim of the present thesis was to examine EF in relation to ADHD, with primary focus on structure (i.e., dimensions) and developmental change. Rooted in the developmental and dimensional perspectives of ADHD, which propose that the disorder represents the extreme of or quantitative delays in traits that are present throughout the general population, four studies (I-IV) based on non-clinical and clinical samples of children at different developmental levels were conducted. Together, the results from Study I-IV suggest that inhibitory control and WM are important components of EF in typically developing children as well as in relation to ADHD symptoms. Of particular interest are the findings from Study II, III, and IV, showing that inhibitory control and WM seem to be of different importance depending on the child’s age. More specifically, the non-clinical and clinical studies suggest that inhibitory control and WM are important in predicting ADHD symptoms, with deficits in inhibitory control primarily being associated with ADHD symptoms for preschool and younger elementary school-aged children, whereas deficits in WM are associated with ADHD symptoms for older elementary school-aged children. In conclusion, the results of the present thesis are consistent with Barkley’s (1997) developmental prediction concerning the relation between EF and ADHD, which suggests that impaired inhibitory control is an early developmental precursor to or a factor that “sets the stage” for deficits in more complex EFs such as WM. The home taking message from the present thesis is that age matters not only in the behavioral, but also in the neuropsychological manifestation of ADHD. To our knowledge, these findings are among the first to show that age is an important factor that should be taken into account in future ADHD research, theory, and treatment.