In both the private and work spheres, multitasking among three or more activities has become and is continuing to evolve as a pervasive element of everyday life, and recent technological advances only seem to be exacerbating the process. Despite attempts to understand the mental processes that let humans successfully multitask, little is known about the functional cognitive level at which these mental processes take place. This thesis makes a case for the involvement of spatial ability (among other cognitive abilities) in successful multitasking behavior. It focuses on the importance of the cognitive off-loading of executive control demands onto spatial ability, due to the inherent complexity of relationships between task goals and deadlines in multitasking scenarios. Importantly, it presents a working hypothesis—the spatiotemporal hypothesis of multitasking—as a tool for making specific predictions about multitasking performance, based on individual and sex differences in spatial ability. In Study 1, individual differences in spatial ability and executive functions emerged as independent predictors of multitasking performance. When spatial ability was decomposed into its subcomponents, only the coordinate (metric), but not categorical (nonmetric), processing of spatial relations was related to multitasking performance. Males outperformed females in both spatial ability and multitasking, and the effects were moderated by menstrual changes, in that sex differences in coordinate spatial processing and multitasking were observed between males and females in the luteal phase of the menstrual cycle, but not between males and females at menses. In Study II, multitasking performance reflected age- and sex-related differences in executive functioning and spatial ability, suggesting that executive functions contribute to multitasking performance across the adult life span, and that reliance on spatial skills for coordinating deadlines is reduced with advancing age. The results of Study III, in which the spatiotemporal hypothesis was directly scrutinized, suggest that the spatial disruption of multiple deadlines interferes with multitasking performance. Overall, these findings suggest that multitasking performance, under certain conditions, reflects independent contributions of spatial ability and executive functioning. Moreover, the results support the distinction between categorical and coordinate spatial processing, suggesting that these two basic relational processes are selectively affected by female sex hormones and are differentially effective, even across the age span, in transforming and handling temporal patterns as spatial relations in the context of multitasking. Finally, fluctuations of sex hormones exhibit a modulating effect on sex differences in spatial ability and multitasking performance. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript.</p>

The growing use of information and communication technologies (ICTs) in college campuses has dramatically increased the potential for multitasking among students who have to juggle classes, school assignments, work, and recreational activities. These students believe that they have become more efficient by performing two or more tasks simultaneously. The use of technology, however, has changed the student’s ability to focus and attend to what they need to learn. Research has shown that multitasking divides students’ attention, which could have a negative impact on their cognition and learning. The purpose of this study was to examine the effects of distractive multitasking on students’ attention and academic performance in a classroom setting. Several studies in cognitive psychology have focused on individuals’ divided attention between simultaneously occurring tasks. Such research has found that, because human attention and capacity to process information are selective and limited, a performance decrement often results when task performance requires divided attention. Distractive tasks are defined as tasks or activities for which cognitive resources are used to process information that is not related to the course material. Multitasking is defined as the engagement in individual tasks that are performed in succession through a process of context switching. Using a non-experimental, correlational research design, the researcher examined the effects of distractive multitasking, with computer devices, during classroom lectures, on students’ academic performance. This study used a monitoring system to capture data that reflected actual multitasking behaviors from students who used computers while attending real-time classroom lectures. The findings showed that there was no statistically significant relationship between the frequency of distractive multitasking (predictor variable) and academic performance (criterion variable), as measured by the midterm and final evaluation scores. The results did not support the hypothesis that distractive computer-based multitasking could have a negative impact on academic performance.

This thesis investigated the effect of visuomotor and working memory 1) task difficulty and 2) multitasking on dynamic functional connectivity in the brain. Studies have only recently begun to investigate functional connectivity within the scope of concurrent dual task or varying task difficulty conditions (Cocchi, Zalesky, et al. 2011; Rietschel et al. 2012). A series of EEG recordings were conducted during execution of visuomotor or working memory tasks within a novel paradigm using BCI2VR custom MATLAB toolbox. Functional connectivity was correlated with task-related coherence (TRCoh) analysis between two task conditions involving either variation in task difficulty or concurrent execution during multitasking within the delta (0 – 4 Hz), theta (4 – 8 Hz), alpha (8 – 12 Hz), beta1 (12-16 Hz), beta2 (16 – 20 Hz) and beta3 (20 – 24 Hz) frequency bands. An increase in coherence was observed with increased cognitive load, during both increased task difficulty and multitasking, in all frequency bands except beta1 and beta2. This may suggest that the psychomotor efficiency hypothesis also applies to multitasking as well as task difficulty. Decreases in beta coherence were observed with increased performance error, indicating that interregional beta coherence may not follow the PEH trend. The increased coherence between brain regions in the alpha, delta and theta bands contributes to the growing volume of research on quantifying cognitive workload and may serve as a future basis on increasing multitasking efficiency during high stress environments. Further research recording multitasking effects on individuals over regular intervals during an extended period of time (months or years) will be required to better understand changes in functional connectivity within the brain.

Denna rapport utgår från en fallstudie på Jensen Sweden och syftar till att förkorta ledtiderna i verksamhetens produktion. Några av problemen som finns i verksamheten är återkommande materialbrist och att produktionen drivs av en subjektiv styrning. Beläggningen i produktionen är ojämn och olika avdelningar är resurseffektiva utan fokus på helheten.Ovanstående problem ger upphov till multitasking som har en rad negativa effekter och som dessutom genererar mycket produkter i arbete. Följden av detta blir långa ledtider och att upptäckten av produktionsavvikelser försvårars.Lösningarna som presenteras i rapporten syftar till att bryta ner takten för ingående produktionsmoment och en struktur tas fram för hur den dagliga styrningen kan bedrivas. Med hjälp av ett Gantt-schema visualiseras beläggningen i produktionen i förhållande till kapaciteten. Detta Gantt-schema visualiserar även den kritiska kedjan. Flexibla team införs för att balanserna kapaciteten och skapa en jämn beläggning mellan stationerna. En viktig parameter för att inte göra systemet för komplext är att minimera antalet order i produktionen. Företaget arbetar med kundspecifika projekt och metoderna som används i rapporten är tänkta att kunna appliceras på företag med liknande produktionsprocesser. / This report is based on a case study at Jensen Sweden and aims to shorten lead times in their production system. Some of the problems are recurring material shortages and that the production planning is driven by a subjective management. The stocking density in the production is uneven and different departments are resource efficient without any focus on the product flow as a whole.The above problems cause multitasking that has a number of negative effects and in addition generate a lot of work in progress. The effect will be long lead times which complicate the discovery of manufacturing deviations.The solutions presented in this report are aimed at breaking down the tact of the incoming production activities, further a structure on how to control the daily management is suggested. Using a Gantt-chart, the stocking density in production relative to the capacity is visualized. The Ganttchart also visualizes the critical chain. Flexible teams are introduced in order to balance the capacity and occupancy between the stations. An important parameter to decrease the complexity of the system is to minimize the number of orders in production. The company is working with customer-specific projects and the intention of the methods used in the report is that they should be to be applicable to companies with similar production processes.

Nesta dissertação buscou-se discutir as escolhas em torno do conhecimento escolar de Ciências Naturais expressas no currículo prescrito e na formação continuada, no contexto do Programa Mais Educação São Paulo, de 2014. Partiu-se da premissa de que tais escolhas marcam de maneiras distintas o trabalho dos professores que atuam no Ensino Fundamental I, no ciclo interdisciplinar, gerando impactos de alguma magnitude sobre a formação escolar dos estudantes. Tratou-se de pesquisa qualitativa que se apoiou nos seguintes procedimentos: análise documental e entrevistas semiestruturadas As fontes foram os documentos curriculares do Programa Mais Educação São Paulo, documentos da formação desenvolvida em uma DRE e as declarações de educadores participantes do processo formativo e da reforma curricular conduzida na rede municipal de ensino, no período de 2015 e 2016. Os quatro sujeitos entrevistados foram: dois coordenadores do DIPED e dois professores-formadores um que atuou com grupos de professores polivalentes e outro, com professores da área de ciências. As análises se apoiaram nos referenciais teóricos de Sacristán e Young, com os conceitos de currículo e conhecimento poderoso; Imbernón, Tardif e Nóvoa, com ideias em torno da formação continuada de professores e suas implicações na prática pedagógica; Krasilchick, Sasseron e Carvalho, com elementos sobre o ensino de ciências, alfabetização científica e natureza da atividade científica. Como resultados, verificouse que, no currículo prescrito, foram indicados os direitos de aprendizagem, porém não estão suficientemente especificados os conhecimentos da disciplina que deveriam ser mobilizados para efetivar a consecução de tais direitos, o que gerou incertezas a respeito dos objetos de ensino neste ciclo. Pode-se dizer que os documentos curriculares deram ênfase aos saberes locais, embora não deixem de salientar a necessidade do conhecimento específico das ciências na escola. Adicionalmente, apesar de a formação continuada na área de ciências ser afirmada como relevante para os professores polivalentes, as experiências analisadas não aprofundaram os conhecimentos específicos, enfatizando prioritariamente os princípios pedagógicos que sustentaram a reforma curricular. Por fim, a ruptura do processo de reforma curricular, em 2017, diante da mudança de gestão municipal, interrompeu o processo formativo dos professores que estava em curso e que teve papel na produção do novo currículo. Descontinuidades constantes como essa marcam as reformas curriculares e as formações continuadas na rede municipal, fragilizando os processos de tomadas de decisão e as condições de trabalho necessárias para os professores desempenharem seu papel com qualidade. / This dissertation seeks to discuss the choices made around school knowledge in Natural Sciences as per the prescribed curriculum as well as in continuing education, in the context of the afore mentioned Programa Mais Educação São Paulo of 2014. The basic assumption adopted is that such choices affect, in distinct ways, the work of teachers involved in Elementary Education Level 1, in the interdisciplinary Cycle, generating considerable impact in the students education. Qualitative research was employed and supported by the following procedures: document analysis and semistructured interviews the sources used were curriculum documents from the Programa Mais Educação São Paulo, records of the teachers training written in a Local Education Department and testimonials from educators who participated both in the training and the curriculum reconducted in the Municipal Education System between the years of 2015 and 2016. The four respondents were two coordinators from DIPED (Local Education Department) and two science teachers. Analysis was supported by theoretical references of Sacristán & Young, with the concepts of curriculum and empowered knowledge; Imbernón, Tardif & Nóvoa, with ideas around continuing education and its implications in pedagogical practice; Krasilchick, Sasseron & Carvalho, with details on science teaching, scientific literacy and nature of scientific activity. As a result, it was possible to verify that the prescribed curriculum indicates the learning rights, but fails to sufficiently specify the knowledge of the subject matter to be set into action to effectively attain such rights, which has generated uncertainties about learning in this cycle. It is possible to say that while the curriculum documents emphasize local knowledge, they also underscore the need for specific knowledge of science at school. Additionally, while continuing education in science subjects is reaffirmed as relevant to multitasking teachers, the assessed experiences do not go deep into specific knowledge, primarily emphasizing the pedagogical principles that serve as foundation to the curriculum reform. Lastly, the interruption of the curriculum reform in 2017, resulting from a change in the city administration caused a rupture in the education process of the teachers involved, who played a role in the production of the new curriculum. Constant disruptions like this are integral part of both the curriculum reform and continuing education practices in the municipal education network, weakening decision-making processes as well compromising as the necessary working conditions that enable teachers to perform their work with quality.

Designs of human-computer systems intended for time-critical multitasking can benefit from an understanding of the human factors that support or limit multitasking performance and a detailed account of the human-machine interactions that unfold in a given task environment. An integrated, computational cognitive model can test and provide such an understanding of the human factors related to multitasking and reveal the dynamic interactions that occur in the task at the level of hundreds of milliseconds. This dissertation provides such a detailed computation model of human multitasking, built for a time-critical, multimodal dual task experiment and validated by the eye tracking data collected from the experiment. This dissertation also develops new approaches to conducting cognitive modeling, which enable efficient and systematical exploration of multitasking strategies, as well as principled model comparisons. The dual task experiment captures many key aspects of real-world multitasking scenarios such as driving. In the experiment, the participant interleaved two tasks: one requires tracking a constantly-moving target with a joystick, and the other requires keying-in responses to objects moving across a radar display. Peripheral visibility and auditory conditions of the experiment were manipulated to assess the influence of peripheral visual information and auditory information on multitasking performance. Detailed eye tracking data were collected, and this dissertation presents a detailed analysis of this set of data, which provides the bases for model development and validation. The cognitive model presented in this dissertation, built based on the Executive Processes-Interactive Control cognitive architecture, accurately accounted for the eye movement data and other behavioral data of each participant using systematic explorations of task strategies and parameters configured for each individual participant. A parallelized cognitive modeling system was developed to accommodate the much increased computational demand of strategy exploration and individualized model building. New model comparison techniques were proposed to determine which strategy best accounts for the empirical data. Payoff analyses were applied, and they revealed people’s tendency to locally optimize task performance based on task payoff as well as instantaneous feedback. The results point to new approaches for building a priori models that predict multitasking performance. This dissertation includes previously published coauthored material.

Heterogeneous platforms play an increasingly important role in modern computer systems. They combine high performance with low power consumption. From mobiles to supercomputers, we see an increasing number of computer systems that are heterogeneous. The most well-known heterogeneous system, CPU+GPU platforms have been widely used in recent years. As they become more mainstream, serving multiple tasks from multiple users is an emerging challenge. A good scheduler can greatly improve performance. However, indiscriminately allocating tasks based on availability leads to poor performance. As modern GPUs have a large number of hardware resources, most tasks cannot efficiently utilize all of them. Concurrent task execution on GPU is a promising solution, however, indiscriminately running tasks in parallel causes a slowdown. This thesis focuses on scheduling OpenCL kernels. A runtime framework is developed to determine where to schedule OpenCL kernels. It predicts the best-fit device by using a machine learning-based classifier, then schedules the kernels accordingly to either CPU or GPU. To improve GPU utilization, a kernel merging approach is proposed. Kernels are merged if their predicted co-execution can provide better performance than sequential execution. A machine learning based classifier is developed to find the best kernel pairs for co-execution on GPU. Finally, a runtime framework is developed to schedule kernels separately on either CPU or GPU, and run kernels in pairs if their co-execution can improve performance. The approaches developed in this thesis significantly improve system performance and outperform all existing techniques.

Classical experiments on honey bee time-memory showed that foragers trained to collect food at a fixed time of day return the following day with remarkable time-accuracy. Previous field experiments revealed that not all foragers return to a food source on unrewarded test days. Rather, there exist 2 subgroups: “persistent” foragers reconnoiter the source; “reticent” foragers wait in the hive for confirmation of source availability. To examine how these foragers contribute to a colony’s ability to reallocate foragers across sources with rapidly changing availabilities, foragers were trained to collect sucrose during a restricted window for several days and observed over 3 days throughout which the feeder was empty. In 2 separate trials, activity monitoring revealed a high level of activity apparently directed at other food sources. This “extracurricular” activity showed extensive temporal overlap with visits to the feeder, indicating that honey bees can manage at least 2 different overlapping time memories.

Why do people travel? Underlying most travel behavior research is the derived-demand paradigm of travel analysis, which assumes that travel demand is derived from the demand for spatially separated activities, traveling is a means to an end (reaching destinations), and travel time is a disutility to be minimized. In contrast, the "positive utility of travel" (PUT) concept suggests that travel may not be inherently disliked and could instead provide benefits or be motivated by desires for travel-based multitasking, positive emotions, or fulfillment. The PUT idea assembles several concepts relevant to travel behavior: utility maximization, motivation theory, multitasking, and subjective well-being. Despite these varied influences, empirical analyses of the PUT concept remain limited in both quantity and scope. There is a need for more fundamental development and classification of the PUT idea and its multifaceted nature. The wide variety and quality of ways to measure PUT attributes are further research challenges. Additionally, few studies investigate both major aspects of the PUT concept--travel activities and travel experiences--simultaneously. Finally, research is only beginning to examine empirical associations between PUT measures and travel behaviors such as mode choice. This dissertation addresses many of these gaps in conceptualizing, measuring, and modeling the PUT concept. First, a literature review strengthens the definition, classification, and empirical support for a PUT, defined as "any benefit(s) accruing to a traveler through the act of traveling." The two primary PUT categories are travel activities (travel-based multitasking) and travel experiences (travel subjective well-being), and the most useful PUT measures involve gathering self-reported assessments of these topics. Based on this review, an online questionnaire is designed and administered to nearly 700 commuters in the Portland, OR, region. The survey includes detailed questions about commute mode choice, activity participation, travel usefulness, positive emotions and fulfillment, and travel liking for a recent home-to-work trip. Next, these PUT measures are empirically examined using factor analyses, finding groupings of activities and common unobserved constructs of hedonic ("Distress," "Fear," "Attentiveness," "Enjoyment") and eudaimonic ("Security," "Autonomy," "Confidence," "Health") subjective well-being. Many of these factors exhibit large variations among travel modes--walking and bicycling commuters are the most satisfied and appear to value time spent exercising--and are predicted (somewhat less strongly) by other trip and traveler characteristics in ordered logit regression and structural equation models. Finally, integrated choice and latent variable models are estimated to examine relationships between measures of the PUT concept and commute mode choice. This is made possible by the unique dataset that collects PUT measures for not only the chosen mode but also modal alternatives. Measures of travel-based multitasking are significantly related to mode choice, suggesting people may be doing things more to pass the time than to be productive. A validated measure of travel subjective well-being is also a significant and positive factor, suggesting people are more likely to choose a mode that makes them happier. Overall, PUT measures greatly increase the explanatory power of the mode choice model. These findings make significant contributions to travel behavior research methods and knowledge. They also offer important implications for transportation policies around promoting nonautomobile travel and planning for autonomous vehicles.

Thesis (M.Sc.), Memorial University of Newfoundland, 2000. / Bibliography: leaves 97-106.