911 resultados para top-down approach
Resumo:
The general goal of the present work was to study whether spatial perceptual asymmetry initially observed in linguistic dichotic listening studies is related to the linguistic nature of the stimuli and/or is modality-specific, as well as to investigate whether the spatial perceptual/attentional asymmetry changes as a function of age and sensory deficit via praxis. Several dichotic listening studies with linguistic stimuli have shown that the inherent perceptual right ear advantage (REA), which presumably results from the left lateralized linguistic functions (bottom-up processes), can be modified with executive functions (top-down control). Executive functions mature slowly during childhood, are well developed in adulthood, and decline as a function of ageing. In Study I, the purpose was to investigate with a cross-sectional experiment from a lifespan perspective the age-related changes in top-down control of REA for linguistic stimuli in dichotic listening with a forced-attention paradigm (DL). In Study II, the aim was to determine whether the REA is linguistic-stimulus-specific or not, and whether the lifespan changes in perceptual asymmetry observed in dichotic listening would exist also in auditory spatial attention tasks that put load on attentional control. In Study III, using visual spatial attention tasks, mimicking the auditory tasks applied in Study II, it was investigated whether or not the stimulus-non-specific rightward spatial bias found in auditory modality is a multimodal phenomenon. Finally, as it has been suggested that the absence of visual input in blind participants leads to improved auditory spatial perceptual and cognitive skills, the aim in Study IV was to determine, whether blindness modifies the ear advantage in DL. Altogether 180-190 right-handed participants between 5 and 79 years of age were studied in Studies I to III, and in Study IV the performance of 14 blind individuals was compared with that of 129 normally sighted individuals. The results showed that only rightward spatial bias was observed in tasks with intensive attentional load, independent of the type of stimuli (linguistic vs. non-linguistic) or the modality (auditory vs. visual). This multimodal rightward spatial bias probably results from a complex interaction of asymmetrical perceptual, attentional, and/or motor mechanisms. Most importantly, the strength of the rightward spatial bias changed as a function of age and augmented praxis due to sensory deficit. The efficiency of the performance in spatial attention tasks and the ability to overcome the rightward spatial bias increased during childhood, was at its best in young adulthood, and decreased as a function of ageing. Between the ages of 5 and 11 years probably at first develops movement and impulse control, followed by the gradual development of abilities to inhibit distractions and disengage attention. The errors especially in bilateral stimulus conditions suggest that a mild phenomenon resembling extinction can be observed throughout the lifespan, but especially the ability to distribute attention to multiple targets simultaneously decreases in the course of ageing. Blindness enhances the processing of auditory bilateral linguistic stimuli, the ability to overcome a stimulus-driven laterality effect related to speech sound perception, and the ability to direct attention to an appropriate spatial location. It was concluded that the ability to voluntarily suppress and inhibit the multimodal rightward spatial bias changes as a function of age and praxis due to sensory deficit and probably reflects the developmental level of executive functions.
Resumo:
Rajavartiolaitos on yhteiskunnallisesti merkittävä turvallisuusviranomainen. Erityisesti laitoksen merellinen rooli sisäisen turvallisuuden kentässä on korostunut sen lakisääteisten merellisten tehtävien ansiosta. Rajavartiolaitoksen merelliselle roolille onkin asetettu huomattavat tavoitteet viraston strategia-asiakirjassa. Rajavartiolaitoksen strategian toimeenpanoa tai siinä suoriutumista ei tieteellisen tutkimuksen keinoin ole aiemmin tutkittu. Tutkimuksen tarkoituksena oli muodostaa rajavartiolaitoksen strategian toimeenpanon tutkimusta tukeva teoreettinen viitekehys. Näkökulma viitekehyksen muodostamiseksi oli merellinen. Kyseisen viitekehyksen avulla mahdollistetaan strategian toimeenpanossa onnistumisen tutkiminen nimenomaisesti merellisestä perspektiivistä. Tutkittaessa toimeenpanoon liittyvien tekijöiden toteutumista tai ilmentymiä rajavartiolaitoksen implementaatioprosessissa voidaan päätyä myös arvioon sen yhteiskunnallisesta vaikuttavuudesta ja viimekädessä roolista. Jatkotutkimuksen tehtävä on varsinainen implementaation tutkiminen nyt muodostettua teoreettista viitekehystä hyödyntäen. Implementaation tutkimuskenttään liittyy useita erilaisia teoreettisia suuntauksia. Teorialähtöisen sisällönanalyysin avulla pyrittiin muodostamaan kattava kuva vallitsevista teorioista varsinaisen paradigman puuttuessa. Sisällönanalyysin analyysirungoksi valittiin topdown- teorian käsitemaailma. Analysoitavat teokset valittiin implementaatiotutkimuksen vahvinta perinnettä edustavien tutkimusjulkaisujen ja artikkeleiden joukosta pyrkimyksenä huomioimaan tutkimuksen alan valtavirtaan kuuluvat merkittävimmät lähestymistavat. Rajavartiolaitoksen strategian toimeenpanon tutkimusta tukevan teorian muodostamiseksi tuli sisällönanalyysistä kumpuavat teoriat sitoa soveltuvin osin reaalimaailmaan eli viraston prosesseihin ja toimintaympäristöön. Tätä varten muodostettiin käsitys rajavartiolaitoksen strategisesta olosuhdeympäristöstä sekä sidottiin toimeenpanon prosessit governanssin teoriaan käyttäen Multiple Govenance Framework -viitekehystä (MGF). Varsinainen viitekehys ja siihen liittyvät tekijät valittiin analysoidusta materiaalista tukeutuen abduktiiviseen päättelyyn. Tutkimuksen johtopäätöksenä voidaan todeta rajavartiolaitoksen edustavan tietyssä määrin top-down-tutkimusperinteeseen liittyviä piirteitä. Tämä teoria ei kuitenkaan kaikilta osin huomio niitä erityispiirteitä, jotka tutkimuksessa tunnistettiin. Yhdistämällä MGF:n ominaisuudet ja top-down-teoriasta soveltuvat tekijät, muodostettiin hypoteesi rajavartiolaitoksen implementaatiota tukevasta viitekehyksestä. Viitekehys sidottiin rajavartiolaitokseen, mutta varsinainen operationalisointi jätettiin jatkotutkimuksen tehtäväksi.
Resumo:
Tutkielman aiheena on tuloskortin kritiikki ja sen analysointi kontingenssiteorian näkökulmasta. Tutkimuksen kohdeyrityksen tuloskortin kritiikkiä on verrattu laskentatoimen tieteellisessä keskustelussa esitettyyn kritiikkiin. Tuloskortin kritiikin ja kontingenssiteorian näkökulmien perusteella tutkimuksen kohdeyrityksen suorituskyvyn mittaamisen kehittämiskohteita on tunnistettu. Tutkimuksen kohdeyritys on suomalainen korkean teknologian yritys, joka on osa yhdysvaltalaista globaalia konsernia. Tutkimuksen teoreettinen tausta perustuu kontingenssiteoriaan ja tuloskortin ja suorituskyvyn mittaamisen doktriiniin. Tutkimus on luonteeltaan toimintaanalyyttinen. Tutkimusaineisto koostuu tieteellisistä artikkeleista, kirjallisuudesta ja kohdeyrityksessä suoritetuista teemahaastatteluista. Tutkielman teoriaosa alkaa Balanced Scorecardin ja muiden tuloskorttien esittelyllä ja vertailulla. Kontingenssiteorian käsittely perustuu tieteellisessä kirjallisuudessa yleisiin tilannetekijöihin: ulkoinen ympäristö, teknologia, strategia ja organisaatiorakenne. Muista tilannetekijöistä käsiteltiin kulttuuripiiri, joka on relevantti tutkimuksen kohdeyrityksen tarkastelussa. Teoreettisen osan selkärangan muodostaa tuloskortin kritiikin analysointi, joka on jaettu Balanced Scorecardin kritiikkiin ja yleiseen tuloskortin kritiikkiin. Kritiikin sisältöä on tulkittu myös kontingenssiteorian avulla. Tutkimuksen kohdeyritys käyttää kolmea erilaista tuloskorttimallia. Tuloskortin kritiikki kohdeyrityksessä vastaa pääosin tieteellisessä keskustelussa esitettyä kritiikkiä. Tuloskortin näkökulmien väliset suhteet, liityntä strategiaan, puutteellinen ajallinen ulottuvuus ja rooli top-down –johtamismallin työkaluna olivat yleisimmät kritiikin kohteet. Kohdeyrityksessä esille nousivat myös tutkimuksen ja tuotekehityksen mittaamisen haasteellisuus, organisaation funktionaaliset rajaaidat, yhdysvaltalainen toiminnanohjaamisen malli ja kohdeyrityksen rooli osana globaalia konsernia. Kontingenssitekijöistä kritiikkiä eniten selittävät ulkoinen ympäristö, organisaatiorakenne ja kulttuuripiiri. Tutkimuksen kohdeyrityksessä tuloskortin kehittämistarpeet kohdistuvat organisaatiorakenteen muokkaamiseen, tuloskortin tavoitteiden viestintään henkilöstölle, tietoteknisiin ratkaisuihin ja konsernin osana toimimiseen. Kontingenssitekijöiden huomioiminen antaa tutkimuksen perusteella hyvän lähtökohdan tuloskortin ja yleisesti suorituskyvyn mittaamisen kehittämiselle yrityksissä.
Resumo:
Prerequisites and effects of proactive and preventive psycho-social student welfare activities in Finnish preschool and elementary school were of interest in the present thesis. So far, Finnish student welfare work has mainly focused on interventions and individuals, and the voluminous possibilities to enhance well-being of all students as a part of everyday school work have not been fully exploited. Consequently, in this thesis three goals were set: (1) To present concrete examples of proactive and preventive psycho-social student welfare activities in Finnish basic education; (2) To investigate measurable positive effects of proactive and preventive activities; and (3) To investigate implementation of proactive and preventive activities in ecological contexts. Two prominent phenomena in preschool and elementary school years—transition to formal schooling and school bullying—were chosen as examples of critical situations that are appropriate targets for proactive and preventive psycho-social student welfare activities. Until lately, the procedures concerning both school transitions and school bullying have been rather problem-focused and reactive in nature. Theoretically, we lean on the bioecological model of development by Bronfenbrenner and Morris with concentric micro-, meso-, exo- and macrosystems. Data were drawn from two large-scale research projects, the longitudinal First Steps Study: Interactive Learning in the Child–Parent– Teacher Triangle, and the Evaluation Study of the National Antibullying Program KiVa. In Study I, we found that the academic skills of children from preschool–elementary school pairs that implemented several supportive activities during the preschool year developed more quickly from preschool to Grade 1 compared with the skills of children from pairs that used fewer practices. In Study II, we focused on possible effects of proactive and preventive actions on teachers and found that participation in the KiVa antibullying program influenced teachers‘ self-evaluated competence to tackle bullying. In Studies III and IV, we investigated factors that affect implementation rate of these proactive and preventive actions. In Study III, we found that principal‘s commitment and support for antibullying work has a clear-cut positive effect on implementation adherence of student lessons of the KiVa antibullying program. The more teachers experience support for and commitment to anti-bullying work from their principal, the more they report having covered KiVa student lessons and topics. In Study IV, we wanted to find out why some schools implement several useful and inexpensive transition practices, whereas other schools use only a few of them. We were interested in broadening the scope and looking at local-level (exosystem) qualities, and, in fact, the local-level activities and guidelines, along with teacherreported importance of the transition practices, were the only factors significantly associated with the implementation rate of transition practices between elementary schools and partner preschools. Teacher- and school-level factors available in this study turned out to be mostly not significant. To summarize, the results confirm that school-based promotion and prevention activities may have beneficial effects not only on students but also on teachers. Second, various top-down processes, such as engagement at the level of elementary school principals or local administration may enhance implementation of these beneficial activities. The main message is that when aiming to support the lives of children the primary focus should be on adults. In future, promotion of psychosocial well-being and the intrinsic value of inter- and intrapersonal skills need to be strengthened in the Finnish educational systems. Future research efforts in student welfare and school psychology, as well as focused training for psychologists in educational contexts, should be encouraged in the departments of psychology and education in Finnish universities. Moreover, a specific research centre for school health and well-being should be established.
Resumo:
Companies today are forced to innovate in order to remain within business. Such innovation projects undertaken by the companies are defined in this study as creative ideas which have been managed through “Stage-Gate” innovation process. This process is used to manage innovation projects as they proceed from being newly created to ready for launching/implementing. This has ensured that the companies manage the innovation project right. However, with so many new creative ideas the companies can come up within limited resources, the companies must rely on Innovation Project Portfolio Management (IPPM) to ensure that they are managing only the right innovation projects. Although, there are many tools and techniques available for use within Project Portfolio Management, there is still no consensus on which are the most effective and no standard framework has been established especially for IPPM. Thus, this study proposes a practical framework for which individual innovative organization can follow as a guideline to manage its innovation project portfolio. The study theoretically first addresses the key differences between project portfolio management of innovation projects and other traditional projects - one of which is the stage nature of innovation projects due to their unclear objectives from the beginning compare to clearly established objectives of traditional projects. Secondly, different tools and techniques which can be used are examined based on the three goals of IPPM: (1) Maximizing the Value of Innovation Project Portfolio: Financial Methods, Decision Trees, Scoring Models and Checklists; (2) Balancing Innovation Project Portfolio: Visual Representations; and (3) Aligning Innovation Project Portfolio with Strategy: Bottom-Up (Scoring Models with Strategic Criteria) and Top-Down (Strategic Buckets). Finally, the two approaches in which IPPM can be integrated with Stage-Gate innovation process are discussed: (1) Gates- Dominated; and (2) Portfolio Reviews-Dominated. Practically, this study investigates IPPM of a case organization, and through analysis of the case study results proposes a practical framework for case organization to improve its current management of innovation project portfolio. This framework is then generalized to propose a final practical framework or guideline for which an innovative organization can follow to manage its innovation project portfolio.
Resumo:
One of the greatest conundrums to the contemporary science is the relation between consciousness and brain activity, and one of the specifi c questions is how neural activity can generate vivid subjective experiences. Studies focusing on visual consciousness have become essential in solving the empirical questions of consciousness. Th e main aim of this thesis is to clarify the relation between visual consciousness and the neural and electrophysiological processes of the brain. By applying electroencephalography and functional magnetic resonance image-guided transcranial magnetic stimulation (TMS), we investigated the links between conscious perception and attention, the temporal evolution of visual consciousness during stimulus processing, the causal roles of primary visual cortex (V1), visual area 2 (V2) and lateral occipital cortex (LO) in the generation of visual consciousness and also the methodological issues concerning the accuracy of targeting TMS to V1. Th e results showed that the fi rst eff ects of visual consciousness on electrophysiological responses (about 140 ms aft er the stimulus-onset) appeared earlier than the eff ects of selective attention, and also in the unattended condition, suggesting that visual consciousness and selective attention are two independent phenomena which have distinct underlying neural mechanisms. In addition, while it is well known that V1 is necessary for visual awareness, the results of the present thesis suggest that also the abutting visual area V2 is a prerequisite for conscious perception. In our studies, the activation in V2 was necessary for the conscious perception of change in contrast for a shorter period of time than in the case of more detailed conscious perception. We also found that TMS in LO suppressed the conscious perception of object shape when TMS was delivered in two distinct time windows, the latter corresponding with the timing of the ERPs related to the conscious perception of coherent object shape. Th e result supports the view that LO is crucial in conscious perception of object coherency and is likely to be directly involved in the generation of visual consciousness. Furthermore, we found that visual sensations, or phosphenes, elicited by the TMS of V1 were brighter than identically induced phosphenes arising from V2. Th ese fi ndings demonstrate that V1 contributes more to the generation of the sensation of brightness than does V2. Th e results also suggest that top-down activation from V2 to V1 is probably associated with phosphene generation. The results of the methodological study imply that when a commonly used landmark (2 cm above the inion) is used in targeting TMS to V1, the TMS-induced electric fi eld is likely to be highest in dorsal V2. When V1 was targeted according to the individual retinotopic data, the electric fi eld was highest in V1 only in half of the participants. Th is result suggests that if the objective is to study the role of V1 with TMS methodology, at least functional maps of V1 and V2 should be applied with computational model of the TMS-induced electric fi eld in V1 and V2. Finally, the results of this thesis imply that diff erent features of attention contribute diff erently to visual consciousness, and thus, the theoretical model which is built up of the relationship between visual consciousness and attention should acknowledge these diff erences. Future studies should also explore the possibility that visual consciousness consists of several processing stages, each of which have their distinct underlying neural mechanisms.
Resumo:
Graphene is a material with extraordinary properties. Its mechanical and electrical properties are unparalleled but the difficulties in its production are hindering its breakthrough in on applications. Graphene is a two-dimensional material made entirely of carbon atoms and it is only a single atom thick. In this work, properties of graphene and graphene based materials are described, together with their common preparation techniques and related challenges. This Thesis concentrates on the topdown techniques, in which natural graphite is used as a precursor for the graphene production. Graphite consists of graphene sheets, which are stacked together tightly. In the top-down techniques various physical or chemical routes are used to overcome the forces keeping the graphene sheets together, and many of them are described in the Thesis. The most common chemical method is the oxidisation of graphite with strong oxidants, which creates a water-soluble graphene oxide. The properties of graphene oxide differ significantly from pristine graphene and, therefore, graphene oxide is often reduced to form materials collectively known as reduced graphene oxide. In the experimental part, the main focus is on the chemical and electrochemical reduction of graphene oxide. A novel chemical route using vanadium is introduced and compared to other common chemical graphene oxide reduction methods. A strong emphasis is placed on electrochemical reduction of graphene oxide in various solvents. Raman and infrared spectroscopy are both used in in situ spectroelectrochemistry to closely monitor the spectral changes during the reduction process. These in situ techniques allow the precise control over the reduction process and even small changes in the material can be detected. Graphene and few layer graphene were also prepared using a physical force to separate these materials from graphite. Special adsorbate molecules in aqueous solutions, together with sonic treatment, produce stable dispersions of graphene and few layer graphene sheets in water. This mechanical exfoliation method damages the graphene sheets considerable less than the chemical methods, although it suffers from a lower yield.
Resumo:
Previous studies have shown that saccadic eye responses but not manual responses were sensitive to the kind of warning signal used, with visual onsets producing longer saccadic latencies compared to visual offsets. The aim of the present study was to determine the effects of distinct warning signals on manual latencies and to test the premise that the onset interference, in fact, does not occur for manual responses. A second objective was to determine if the magnitude of the warning effects could be modulated by contextual procedures. Three experimental conditions based on the kind of warning signal used (visual onset, visual offset and auditory warning) were run in two different contexts (blocked and non-blocked). Eighteen participants were asked to respond to the imperative stimulus that would occur some milliseconds (0, 250, 500 or 750 ms) after the warning signal. The experiment consisted in three experimental sessions of 240 trials, where all the variables were counterbalanced. The data showed that visual onsets produced longer manual latencies than visual offsets in the non-blocked context (275 vs 261 ms; P < 0.001). This interference was obtained, however, only for short intervals between the warning and the stimulus, and was abolished when the blocked context was used (256 vs 255 ms; P = 0.789). These results are discussed in terms of bottom-up and top-down interactions, mainly those related to the role of attentional processing in canceling out competitive interactions and suppressive influences of a distractor on the relevant stimulus.
Resumo:
Diplomityön tavoitteena on tutkia valmistusstrategian muodostamista rajaten tarkastelu yhteen tuoteperheeseen. Työn teoriaosuudessa suoritaan kirjallisuuskatsaus, jonka keskeisempänä tuloksena luodaan teoriaviitekehys valmistusstrategian muodostamisesta. Valmistusstrategian osa-alueiksi rajataan toimitusketjun rakenne, tuotantomuodon valinta, kapasiteetin suunnittelu sekä materiaalinohjaus. Työn soveltavassa osuudessa muodostetaan esitetyn teoriaviitekehyksen avulla valmistusstrategiaehdotelma Case – yrityksen uudelle tuoteperheelle. Valmistusstrategian tavoitteet sekä rajoitteet tunnistetaan tarkastelemalla yrityksen ylemmän tason strategioita, markkinavaatimuksia, valmistuksen resursseja sekä päivittäistä toimintaa. Kokonaisuudessaan diplomityö käsittelee valmistusstrategian muodostamista aikaisempaa kirjallisuutta yksityiskohtaisemmin ja käytännönläheisemmästä näkökulmasta. Case – yrityksen uudelle tuoteperheelle ehdotettu valmistusstrategia todetaan seuraavan yleisesti hyviä toimitusketjun johtamisen periaatteita.
Resumo:
In marine benthic communities, herbivores consume a considerable proportion of primary producer biomass and, thus, generate selection for the evolution of resistance traits. According to the theory of plant defenses, resistance traits are costly to produce and, consequently, inducible resistance traits are adaptive in conditions of variable herbivory, while in conditions of constant/strong herbivory constitutive resistance traits are selected for. The evolution of resistance plasticity may be constrained by the costs of resistance or lack of genetic variation in resistance. Furthermore, resource allocation to induced resistance may be affected by higher trophic levels preying on herbivores. I studied the resistance to herbivory of a foundation species, the brown alga Fucus vesiculosus. By using factorial field experiments, I explored the effects of herbivores and fish predators on growth and resistance of the alga in two seasons. I explored genetic variation in and allocation costs of resistance traits as well as their chemical basis and their effects on herbivore performance. Using a field experiment I tested if induced resistance spreads via water-borne cues from one individual to another in relevant ecological conditions. I found that in the northern Baltic Sea F. vesiculosus communities, strength of three trophic interactions strongly vary among seasons. The highly synchronized summer reproduction of herbivores promoted their escape from the top-down control of fish predators in autumn. This resulted into large grazing losses in algal stands. In spring, herbivore densities were low and regulated by fish, which, thus,enhanced algal growth. The resistance of algae to herbivory increased with an increase in constitutive phlorotannin content. Furthermore, individuals adopted induced resistance when grazed and when exposed to water-borne cues originating from grazing of conspecific algae both in the laboratory and in field conditions. Induced resistance was adopted to a lesser extent in the presence of fish predators. The results in this thesis indicate that inducible resistance in F. vesiculosus is an adaptation to varying herbivory in the northern Baltic Sea. The costs of resistance and strong seasonality of herbivory have likely contributed to the evolution of this defense strategy. My findings also show that fish predators have positive cascading effects on F. vesiculosus which arise via reduced herbivory but possibly also through reduced resource allocation to resistance. I further found evidence that the spread of resistance via water-borne cues also occurs in ecologically realistic conditions in natural marine sublittoral. Thus, water-borne induction may enable macroalgae to cope with the strong grazing pressure characteristic of marine benthic communities. The results presented here show that seasonality can have pronounced effects on the biotic interactions in marine benthic communities and thereafter influence the evolution of resistance traits in primary producers.
Resumo:
This qualitative case study explored the process of implementing Experiential Education (EXED) in Yukon Territory Kindergarten to Grade 12 (K-12) schools with a particular focus on investigating: (a) understandings of EXED and the drivers behind its implementation, (b) factors contributing to EXED’s suitability for Yukon schools, and (c) factors supporting and challenging the implementation of EXED in Yukon schools. Data collection involved interviews with Yukon Department of Education (YDE) staff members, principals and teachers, document collection, and reflective note collection. Findings indicated that EXED was understood as more of a methodology than a philosophy for teaching and learning. EXED implementation was primarily driven by bottom-up (school/ teacher) initiatives and was secondarily supported by top-down (YDE) efforts. The process of implementation was supported by three main factors and was challenged primarily by six factors. The results also pointed to three factors that made EXED suitable for implementation in Yukon schools.
Resumo:
Cognitive control involves the ability to flexibly adjust cognitive processing in order to resist interference and promote goal-directed behaviour. Although frontal cortex is considered to be broadly involved in cognitive control, the mechanisms by which frontal brain areas implement control functions are unclear. Furthermore, aging is associated with reductions in the ability to implement control functions and questions remain as to whether unique cortical responses serve a compensatory role in maintaining maximal performance in later years. Described here are three studies in which electrophysiological data were recorded while participants performed modified versions of the standard Sternberg task. The goal was to determine how top-down control is implemented in younger adults and altered in aging. In study I, the effects of frequent stimulus repetition on the interference-related N450 were investigated in a Sternberg task with a small stimulus set (requiring extensive stimulus resampling) and a task with a large stimulus set (requiring no stimulus resampling).The data indicated that constant stimulus res amp ling required by employing small stimulus sets can undercut the effect of proactive interference on the N450. In study 2, younger and older adults were tested in a standard version of the Sternberg task to determine whether the unique frontal positivity, previously shown to predict memory impairment in older adults during a proactive interference task, would be associated with the improved performance when memory recognition could be aided by unambiguous stimulus familiarity. Here, results indicated that the frontal positivity was associated with poorer memory performance, replicating the effect observed in a more cognitively demanding task, and showing that stimulus familiarity does not mediate compensatory cortical activations in older adults. Although the frontal positivity could be interpreted to reflect maladaptive cortical activation, it may also reflect attempts at compensation that fail to fully ameliorate agerelated decline. Furthermore, the frontal positivity may be the result of older adults' reliance on late occurring, controlled processing in contrast to younger adults' ability to identify stimuli at very early stages of processing. In the final study, working memory load was manipulated in the proactive interference Sternberg task in order to investigate whether the N450 reflects simple interference detection, with little need for cognitive resources, or an active conflict resolution mechanism that requires executive resources to implement. Independent component analysis was used to isolate the effect of interference revealing that the canonical N450 was based on two dissociable cognitive control mechanisms: a left frontal negativity that reflects active interference resolution, , but requires executive resources to implement, and a right frontal negativity that reflects global response inhibition that can be relied on when executive resources are minimal but at the cost of a slowed response. Collectively, these studies advance understanding of the factors that influence younger and older adults' ability to satisfy goal-directed behavioural requirements in the face of interference and the effects of age-related cognitive decline.
Resumo:
This qualitative case study explored the process of implementing Experiential Education (EXED) in Yukon Territory Kindergarten to Grade 12 (K-12) schools with a particular focus on investigating: (a) understandings of EXED and the drivers behind its implementation, (b) factors contributing to EXED's suitability for Yukon schools, and (c) factors supporting and challenging the implementation of EXED in Yukon schools. Data collection involved interviews with Yukon Department of Education (YDE) staff members, principals and teachers, document collection, and reflective note collection. Findings indicated that EXED was understood as more of a me~odology than a philosophy for teaching and learning. EXED implementation was primarily driven by bottom-up (school! teacher) initiatives and was secondarily supported by top-down (YDE) efforts. The process of implementation was supported by three main factors and was challenged primarily by six factors. The results also pointed to three factors that made EXED suitable for implementation in Yukon schools.
Resumo:
In times of educational change, educators are given the task of implementing new initiatives that meet the needs of a changing environment; yet, they are often dismissed from developmental phases of the reform. This top-down structure deters educators’ personal capacity building as their knowledge, values, assumptions, and beliefs are not acknowledged or explicitly developed as part of the initiative. This study explored Ontario dental hygiene educators’ perspectives of how they may build personal capacity during an externally mandated national curriculum reform, the Entry-to-Practice Competencies and Standards for Canadian Dental Hygienists (National Competencies). Narratives were collected from 5 dental hygiene educators of diverse educational training and teaching organizations. Three themes emerged that included perceptions of structural influence, perceptions of learning access, and perceptions of identity. Each theme was linked to tasks that were required to build personal capacity for sustainable school change. The theoretical framework and the required tasks demonstrated the interconnectedness between educators, leaders, and the organization for building educators’ personal capacity.
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The role of psychological strategies on endurance performance and cognitive function in the heat is unclear. This thesis tested the effects of a two-week motivational self-talk (MST) intervention - specific to heat stress - on endurance capacity and cognitive function in the heat (35°C 50% RH). The study utilized a pre-test / post-test design testing endurance capacity using a time to exhaustion test (TTE) after exercise-induced hyperthermia. Cognitive function (e.g executive function) was tested at baseline in thermoneutral (22°C 30% RH), before (R1) and after the TTE (R2). MST led to a significant improvement (~30%) in TTE and significantly faster completion time with fewer errors made on executive function tasks at baseline and R2, but not in R1, while there were no differences in the control group. Overall, these results indicate that using a top-down regulation strategy consisting of self-contextualized MST can improve physical and cognitive performance in the heat.