Phosphatidylserine (PS) is an endogenously occurring phospholipid that has been shown to have cognition and mood enhancing properties in humans, possibly through its role as an enzyme co-factor in cellular signal transduction. Specifically, PS has been identified as activator of classical isoforms of protein kinase C, an enzyme known to be involved in the growth and differentiation of neural cells, and is therefore thought to play a role in the protection of neurons. The purpose of this study was to examine the effects of supplementation with PS and caffeine on measures of cognition, reaction time and mood prior to and following an exercise stress. Twenty, healthy, resistance trained males (17) and females (3) (mean ± SD; age: 22.75 ± 3.27 yrs; height: 177.03 ± 8.44cm; weight: 78.98 ± 11.24kg; body fat%: 14.28 ± 6.6), volunteered to participate in this randomized, double-blind, placebo-controlled study. Participants were assigned to a PS group (400mg/day PS; 100mg/day caffeine, N=9) or PL (16g/day Carbs, N=11) delivered in the form of 4 candy chews identical in size, shape and color. Subjects performed an acute bout of full body resistance exercise, prior to (T1) and following 14 days of supplementation (T2). Measures of reaction time (Dynavision® D2 Visuomotor Training Device), cognition (Serial Subtraction Test, SST), and mood (Profile of Mood States, POMS) were assessed immediately before and following resistance exercise in both T1 and T2. Data was analyzed using two-way ANCOVA and repeated measures ANOVA. Supplementation with 400mg PS and 100mg caffeine did not have a significant impact upon measures of reaction time or cognition between groups at baseline or following acute resistance exercise. However, there was a non-significant trend to the attenuation of fatigue iv between groups, following acute resistance exercise (p = 0.071). Interestingly, our data suggests that acute resistance exercise alone may improve cognitive function. Although more research is necessary regarding optimal dosage and supplementation duration, the current findings suggest that supplementation 400mg/day PS with 100mg/day caffeine may attenuate fatigue following acute resistance exercise. It is possible that the lack of significance may be the result of both an inhibition of the PS activated pathway and a withdrawal effect from caffeine.

Norrvatten är den fjärde största dricksvattenproducenten i Sverige. De producerar och distribuerar dricksvatten till 14 kommuner norr om Stockholm. Norrvatten har under en tid studerat alternativa processer för att optimera och öka produktionskapaciteten och effektiviteten i deras dricksvattenreningsverk vid Görvälnverket.  I detta projekt har en pilotanläggning använts för att studera och optimera ett hybridprocessteg bestående av ett koagulerings- och ultrafiltreringssteg med syfte att avlägsna humusämnen från ytvatten. Effekten av pH, reaktionstid och olika matarvattenkvaliteter (Görväln, Fyrisån och sandfiltrat) analyserades genom en serie experiment utförda med pilotanläggningen. Den mest optimala placeringen av ett eventuellt ultrafiltreringssteg i reningsprocessen studerades även.   Resultaten från experimenten påvisade att pH mellan 6.1 och 6.7 inte hade någon effekt på reningen av fDOM. Mer signifikanta skillnader i rening kunde observeras mellan de olika koaguleringsdoserna, vilket indikerar att denna parameter är viktigare än pH. Reaktionstiden hade ingen märkbar effekt på anläggningens reningseffektivitet. Däremot ökade transmembrantrycket tio gånger snabbare under experimenten med den kortare reaktionstiden. Dessa resultat antyder att de bildade flocken var mindre och därmed blev mer tätt packade i ultrafiltret vilket i sin tur lett till det snabbt ökande trycket i membranet. En avskiljning av minst 50 %, men inte mer än 60 %, av det ingående fDOM kunde uppnås med alla matarvatten utom sandfiltratet, som hade en reningseffektivitet på 18 %. Vattnet från Fyrisån visade sig vara en utmaning för anläggningen att hantera, då trycket snabbt byggdes upp i membranet vilket tyder på att anläggningen inte klarar för starkt förorenade vatten. Resultaten från sandfiltratexperimenten visade att ett ultrafiltreringssteg efter sandfiltren skulle kunna vara en möjlig placering av ultrafiltren. Ytterligare studier krävs dock för att med säkerhet kunna bestämma den mest optimala placeringen.   Sammanfattningsvis visar resultaten från experimenten lovande tecken på att en ultrafiltreringsprocess är ett möjligt alternativ för att öka Norrvattens dricksvattenreningsverks effektivitet och kapacitet. / Norrvatten is the fourth largest drinking water producer in Sweden. They produce and distribute drinking water to 14 municipalities north of Stockholm. For some time, Norrvatten has studied alternative processes in order to optimise and increase the production capacity and efficiency of their drinking water treatment plant at Görvälnverket.   In this project, a small-scale pilot plant has been used to study and optimise a coagulation and ultrafiltration hybrid process step in order to remove humic substances from surface water. The effect of pH, reaction time, and different feed water qualities (Görväln, Fyrisån and Görväln full scale sand filtrate) were analysed through a series of experiments performed with the pilot plant. The most optimal placement of an eventual ultrafiltration step was also studied.  The results from the experiments suggested that pH in the range 6.1 to 6.7 had no large effect on the removal efficiency of fluorescent dissolved organic matter (fDOM). Instead, differences in removal efficiency could be observed between coagulant dosages which indicates that this parameter is of more importance than pH. At higher pH (> 7) removal was significantly lower. The reaction time had no effect on the removal efficiency of the plant. However, the transmembrane pressure increased ten times faster during the experiments with a shorter reaction time. These results suggested that the floc formed were smaller and thereby more tightly packed in the ultrafilter which in turn increased the pressure in the membrane. An fDOM removal of at least 50 %, though no more than 60 %, was achieved with all feed waters except for the sand filtrate which had a removal efficiency of 18 %. However, highly concentrated humic waters such as Fyrisån proved to be challenging for the plant to handle since the pressure built up rather quickly in the membrane. The sand filtrate feed water experiments indicated that an ultrafiltration step after a sand filtration process would be effective. However, further studies are required to be able to determine the most optimal placement of the ultrafiltration process.  In conclusion, the results achieved with the pilot plant show promising signs of an ultrafiltration process being a viable alternative for Norrvatten to increase their drinking water treatment plant’s efficiency and capacity.

No / Metamemory is integral for strategizing about memory intentions. This study investigated the prospective memory (PM) deficit in Parkinson's disease (PD) from a metamemory viewpoint, with the aim of examining whether metamemory deficits might contribute to PM deficits in PD. METHOD: Sixteen patients with PD and 16 healthy older adult controls completed a time-based PM task (initiating a key press at two specified times during an ongoing task), and an event-based PM task (initiating a key press in response to animal words during an ongoing task). To measure metamemory participants were asked to predict and postdict their memory performance before and after completing the tasks, as well as complete a self-report questionnaire regarding their everyday memory function. RESULTS: The PD group had no impairment, relative to controls, on the event-based task, but had prospective (initiating the key press) and retrospective (recalling the instructions) impairments on the time-based task. The PD group also had metamemory impairments on the time-based task; they were inaccurate at predicting their performance before doing the task but, became accurate when making postdictions. This suggests impaired metamemory knowledge but preserved metamemory monitoring. There were no group differences regarding PD patients' self-reported PM performance on the questionnaire. CONCLUSIONS: These results reinforce previous findings that PM impairments in PD are dependent on task type. Several accounts of PM failures in time-based tasks are presented, in particular, ways in which mnemonic and metacognitive deficits may contribute to the difficulties observed on the time-based task.

Le traumatisme craniocérébral léger (TCCL) a des effets complexes sur plusieurs fonctions cérébrales, dont l’évaluation et le suivi peuvent être difficiles. Les problèmes visuels et les troubles de l’équilibre font partie des plaintes fréquemment rencontrées après un TCCL. En outre, ces problèmes peuvent continuer à affecter les personnes ayant eu un TCCL longtemps après la phase aiguë du traumatisme. Cependant, les évaluations cliniques conventionnelles de la vision et de l’équilibre ne permettent pas, la plupart du temps, d’objectiver ces symptômes, surtout lorsqu’ils s’installent durablement. De plus, il n’existe pas, à notre connaissance, d’étude longitudinale ayant étudié les déficits visuels perceptifs, en tant que tels, ni les troubles de l’équilibre secondaires à un TCCL, chez l’adulte. L’objectif de ce projet était donc de déterminer la nature et la durée des effets d’un tel traumatisme sur la perception visuelle et sur la stabilité posturale, en évaluant des adultes TCCL et contrôles sur une période d’un an. Les mêmes sujets, exactement, ont participé aux deux expériences, qui ont été menées les mêmes jours pour chacun des sujets. L’impact du TCCL sur la perception visuelle de réseaux sinusoïdaux définis par des attributs de premier et de second ordre a d’abord été étudié. Quinze adultes diagnostiqués TCCL ont été évalués 15 jours, 3 mois et 12 mois après leur traumatisme. Quinze adultes contrôles appariés ont été évalués à des périodes identiques. Des temps de réaction (TR) de détection de clignotement et de discrimination de direction de mouvement ont été mesurés. Les niveaux de contraste des stimuli de premier et de second ordre ont été ajustés pour qu’ils aient une visibilité comparable, et les moyennes, médianes, écarts-types (ET) et écarts interquartiles (EIQ) des TR correspondant aux bonnes réponses ont été calculés. Le niveau de symptômes a également été évalué pour le comparer aux données de TR. De façon générale, les TR des TCCL étaient plus longs et plus variables (plus grands ET et EIQ) que ceux des contrôles. De plus, les TR des TCCL étaient plus courts pour les stimuli de premier ordre que pour ceux de second ordre, et plus variables pour les stimuli de premier ordre que pour ceux de second ordre, dans la condition de discrimination de mouvement. Ces observations se sont répétées au cours des trois sessions. Le niveau de symptômes des TCCL était supérieur à celui des participants contrôles, et malgré une amélioration, cet écart est resté significatif sur la période d’un an qui a suivi le traumatisme. La seconde expérience, elle, était destinée à évaluer l’impact du TCCL sur le contrôle postural. Pour cela, nous avons mesuré l’amplitude d’oscillation posturale dans l’axe antéropostérieur et l’instabilité posturale (au moyen de la vitesse quadratique moyenne (VQM) des oscillations posturales) en position debout, les pieds joints, sur une surface ferme, dans cinq conditions différentes : les yeux fermés, et dans un tunnel virtuel tridimensionnel soit statique, soit oscillant de façon sinusoïdale dans la direction antéropostérieure à trois vitesses différentes. Des mesures d’équilibre dérivées de tests cliniques, le Bruininks-Oseretsky Test of Motor Proficiency 2nd edition (BOT-2) et le Balance Error Scoring System (BESS) ont également été utilisées. Les participants diagnostiqués TCCL présentaient une plus grande instabilité posturale (une plus grande VQM des oscillations posturales) que les participants contrôles 2 semaines et 3 mois après le traumatisme, toutes conditions confondues. Ces troubles de l’équilibre secondaires au TCCL n’étaient plus présents un an après le traumatisme. Ces résultats suggèrent également que les déficits affectant les processus d’intégration visuelle mis en évidence dans la première expérience ont pu contribuer aux troubles de l’équilibre secondaires au TCCL. L’amplitude d’oscillation posturale dans l’axe antéropostérieur de même que les mesures dérivées des tests cliniques d’évaluation de l’équilibre (BOT-2 et BESS) ne se sont pas révélées être des mesures sensibles pour quantifier le déficit postural chez les sujets TCCL. L’association des mesures de TR à la perception des propriétés spécifiques des stimuli s’est révélée être à la fois une méthode de mesure particulièrement sensible aux anomalies visuomotrices secondaires à un TCCL, et un outil précis d’investigation des mécanismes sous-jacents à ces anomalies qui surviennent lorsque le cerveau est exposé à un traumatisme léger. De la même façon, les mesures d’instabilité posturale se sont révélées suffisamment sensibles pour permettre de mesurer les troubles de l’équilibre secondaires à un TCCL. Ainsi, le développement de tests de dépistage basés sur ces résultats et destinés à l’évaluation du TCCL dès ses premières étapes apparaît particulièrement intéressant. Il semble également primordial d’examiner les relations entre de tels déficits et la réalisation d’activités de la vie quotidienne, telles que les activités scolaires, professionnelles ou sportives, pour déterminer les impacts fonctionnels que peuvent avoir ces troubles des fonctions visuomotrice et du contrôle de l’équilibre. / Mild traumatic brain injury (mTBI) has complex effects on several brain functions that can be difficult to assess and follow-up. Visual and balance problems are frequently reported after an mTBI. Furthermore, these problems can still affect mTBI individuals far beyond the acute stage of injury. However, standard clinical assessments of vision and balance most often fail to objectivize these symptoms, especially if they are lingering. Moreover, to our knowledge, no longitudinal study investigated either mTBI-related deficits of visual perception per se, or mTBI-related balance deficits in adults. The aim of this project was to determine the nature and duration of the effects of such a traumatism on visual perception as well as on postural stability, by evaluating mTBI and control adults over a one-year period. Exactly the same subjects participated in both experiments, which took place on the same days for every subject. The impact of mTBI on the visual perception of sine-wave gratings defined by first-and second-order characteristics was, first, investigated. Fifteen adults diagnosed with mTBI were assessed at 15 days, 3 months and 12 months after injury. Fifteen matched controls followed the same testing schedule. Reaction times (RTs) for flicker detection and motion direction discrimination were measured. Stimulus contrast of first- and second-order patterns was equated to control for visibility, and correct-response RT means, standard deviations (SDs), medians, and interquartile ranges (IQRs) were calculated. The level of symptoms was also evaluated to compare it to RT data. In general in mTBI, RTs were longer and more variable (ie., larger SDs and IQRs), than those of controls. In addition, mTBI participants’ RTs to first-order stimuli were shorter than those to second-order stimuli, and more irregular for first- than for second-order stimuli in the motion condition. All these observations were made over the 3 sessions. The level of symptoms observed in mTBI was higher than that of control participants and this difference did also persist up to one year after the brain injury, despite an improvement. The second experiment, then, investigated the impact of mTBI on postural control. To achieve that, antero-posterior body sway amplitude (BSA) and postural instability (given by body sway velocity root mean square, vRMS) during upright stance, feet together, on a firm surface, were measured in five different conditions: with eyes closed and in a 3D virtual reality tunnel, either static or sinusoidally moving in the antero-posterior direction at 3 different velocities. Balance measures derived from clinical tests, Bruininks-Oseretsky Test of Motor Proficiency 2nd edition (BOT-2) and Balance Error Scoring System (BESS), were also used. Participants diagnosed with mTBI exhibited more postural instability (i.e. higher body sway vRMS) than control participants at 2 weeks and at 3 months post-injury, regardless of the testing condition. These mTBI-related balance deficits were no longer present one year postinjury. These results also suggest that visual processing impairments revealed in the first experiment might have contributed to mTBI-related balance deficits. Anteroposterior BSA as well as measures derived from clinical tests for balance assessment did not appear to be sensitive enough to quantify postural deficits of mTBI participants. The combination of RT measures with particular stimulus properties appeared to be a highly sensitive method for measuring mTBI-induced visuomotor anomalies, and to provide a fine probe of the underlying mechanisms when the brain is exposed to mild trauma. Likewise, postural instability measures prove to be sensitive enough for measuring mTBI-induced balance deficits. Developing screening tests in this respect intended for early post-mTBI use would be of interest. Also, studying relationships of such deficits with performance in daily life activities, such as school, work, or sports, is crucial in order to determine the functional impacts of these alterations in visuomotor and balance functions.

The purpose of this thesis was to develop methodology by which treatments for the cognitive impairments in Huntington's disease (HD) could be tested. As such, the thesis focused mainly on evaluating rats with quinolinic acid (QA) lesions of the striatum, as this manipulation mimics some aspects of the neural damage in Huntington's disease, to try to identify cognitive deficits of HD resulting from cell loss in the striatum. In the first part (Chapters 3-5), the role of the striatum in implicit memory was investigated. Chapter 3 compared the performance of rats and humans on a reaction time task that evaluated implicit memory by presenting visual stimuli with differing probabilities which change over time. Although rats made higher percentage of incorrect responses and late errors, both groups showed a similar pattern of reaction times. Chapter 4 investigated whether implicit memory (the computation of probabilities to predict the location of a stimulus) was affected by selective blockade of dopaminergic transmission at the D1 or D2 receptors by SCH-23390 and raclopride, respectively. Reaction times were slower with SCH-23390 and raclopride, but only SCH-23390 reduced errors to the least probable target location. Chapter 5 used the same task to evaluate implicit memory in rats with QA lesions of the dorsomedial striatum (DMS). Implicit memory was not affected by lesions of the DMS, which suggested that once a task that requires implicit memory has been learned, the DMS was not involved in sustaining the performance of the task. The second part of this thesis (Chapter 6), explored the contribution of the DMS in habit formation. DMS lesioned rats did not show habitual responding, and were not impaired in learning a new goal-directed behaviour. The third part (Chapters 7 and 8), investigated the role of the dorsal striatum in reversal learning, attentional set-formation, and set-shifting. Dorsal striatum lesioned rats were not impaired in reversal learning, but had a diminished shift-cost, which suggested that dorsal striatum lesions disrupted the formation of attentional sets. These results showed that although QA lesions of the dorsal striatum mimic some aspects of the neural damage in HD, they did not result in the same cognitive deficits observed in patients with HD, at least using the tasks presented in this thesis. However, other animal models of HD could be evaluated using the different tasks presented in this thesis to continue the search of a reliable animal model of HD in which treatments for the disease could be evaluated.

<p>Profesionalnim vozačima osnovno zanimanje je upravljanje motornim vozilom. Izvođenje radnih zadatka podrazumeva stalnu napregnutost pažnje vezanu za vidne i zvučne podražaje koji se brzo smenjuju, &scaron;to zahteva da vozač adekvatno i tačno reaguje na promene. Prijem informacija, obrada, dono&scaron;enje odluke i izvr&scaron;avanje motornog odgovora su procesi koji prate jedni druge i čine vreme percepcije-reakcije (VPR). Uslovi i zahtevi rada za profesionalne vozače su isti i za mlađe i starije radnike i povezani su sa velikom odgovorno&scaron;ću za ljudske živote i materijalna dobra, bez obzira na to &scaron;to je poznato, da se radna sposobnost menja zbog prirodnog procesa starenja. Merenje i utvrđivanje vrednosti VPR je važan deo ispitivanja u okviru procene zdravstvene sposobnosti za bezbednu vožnju. Ciljevi: Utvrđivanje vrednosti VPR kod profesionalnih vozača i poređenje sa kontrolnom grupom. Ispitivanje uticaja starosti i vozačkog iskustva na VPR kod profesionalnih vozača. Materijal i metode : Ova studija procenjuje deo sposobnosti profesionalnih vozača merenjem VPR prostog i složenog, važnih za sigurnost u vožnji. Istraživanje je sprovedeno u vremenskom periodu od devet meseci i obuhvatilo je 548 ispitanika mu&scaron;kog pola, starosti od 21 do 65 godina. Eksperimentalnu grupu je činilo 278 ispitanika (profesionalni vozači), a kontrolnu 270 ispitanika kojima osnovno zanimanje nije profesionalna vožnja. Testiranje je izvedeno pomoću hardversko-softverskog sistema za određivanje vrednosti VPR na proste i složene audio-vizuelne podražaje. Merenja su sprovedena na tri nivoa težine zadatka: prosto VPR, i testovi složenog VPR na promenu pozicije podražaja i vrste boje. Rezultati: Utvrđene su značajno niže srednje vrednosti VPR na sva tri nivoa testiranja u grupi profesionalnih vozača u poređenju sa kontrolnom grupom. Utvrđena je pozitivna povezanost srednjih vrednosti VPR sa godinama života i dužinom profesionalnog vozačkog radnog staža na svim testovima u grupi profesionalnih vozača. Nisu utvrđene značajne razlike u procentu pogre&scaron;nih odgovora u odnosu na životno doba i dužinu vozačkog staža, &scaron;to govori o pozitivnim efektima profesionalne prakse u vožnji. Nisu utvrđene značajne razlike srednjih vrednosti VPR kod vozača u gradskom ili međugradskom saobraćaju, kao i u odnosu na broj pređenih kilometara mesečno na svim testovima. Obeležja poput starosti (godine života), profesionalne prakse (iskustvo u godinama profesionalne vožnje), neke promene zdravstvenog stanja (postojanje bolesti ili drugih poremećaja) u grupi profesionalnih vozača pokazale su se kao prediktori sa značajnim nivoom povezanosti sa vrednostima VPR. Metodom vi&scaron;estruke regresione analize smo ispitali smo povezanost vrednosti VPR sa posmatranim prediktorima kada ih analiziramo zajedno uzimajući u obzir njihovu međusobnu interakciju. Regresioni model pokazuje kako skup posmatranih obeležja predviđa promene VPR. Zaključak: Utvrđene vrednosti i prediktivni model promena VPR profesionalnih vozača mogu biti korisni podaci u svakodnevnom radu zdravstvenim ustanovama koje procenjuju vozačku sposobnost, kako bi se identifikovali potencijalno rizični vozači sa vi&scaron;im vrednostima VPR, zamorenih i osoba sa početnim o&scaron;tećenjima nervnog sistema, sklonih povredama u saobraćaju i na radu, u cilju prevencije saobraćajnih udesa i povreda, kao i osiguranja da vozači imaju sposobnosti neophodne za bezbednu vožnju. Utvrđene vrednosti VPR mogle bi naći primenu pri oceni radne sposobnosti i kod radnika na drugim zanimanjima gde se očekuje brza i tačna reakcija na određeni podražaj.</p> / <p>The term professional driver refers to people whose main occupation is driving a motor vehicle. Performing work tasks implies a constant strain of attention related to visual and audible stimuli that change quickly, which requires the driver to respond adequately and accurately to changes. Receiving information, processing, making a decision and executing a motor response are processes that accompany each other and make up the perception-reaction time (PRT). The working conditions and requirements for professional drivers are the same for both younger and older workers and are associated with great responsibility for human lives and material goods, regardless of the fact that it is known that working ability changes due to the natural aging process. Measuring and determining the value of PRT is an important part of testing as part of the assessment of health fitness for safe driving. Aims: Determination of PRT values in professional drivers and comparison with the control group. Examination of the effects of aging and driving experience on the PRT of professional drivers. Material and methods: This study assesses part of the ability of professional drivers by measuring simple and complex PRT important for driving safety. The study was conducted over a period of nine months and included 548 male respondents, aged 21 to 65 years. The experimental group consisted of 278 respondents (professional drivers), and the control group consisted of 270 respondents whose main occupation is not professional driving. Testing was performed using a hardware-software system to determine the value of PRT on simple and complex audio-visual stimuli. Measurements were carride out at three levels of task difficulty: simple PRT, and complex PRT tests to change stimuli position and color type. Results: Significantly lower PRT mean values were found at all three levels of testing in the group of professional drivers compared to the control group. A positive correlation was found between the mean PRT values with age and experience of professional driving on all tests in the group of professional drivers. No significant differences were found in the percentage of incorrect answers in relation to the age and driving experience, which shows the positive effects of professional driving practice. No significant differences were found in the mean PRT values on all tests for drivers in urban or interurban traffic and in relation to the number of kilometers per month. Individual characteristics as, aging, professional practice (experience in years of professional driving), changes in health status (existence of diseases or other disorders) in the group of professional drivers showed to be predictors with a significant level of correlation with PRT values. Using the method of multiple regression analysis, we examined the correlation of PRT values with the observed predictors when we analyze them together, taking into account their mutual interaction.The regression model shows how the set of observed features predicts changes in PRT. Conclusion: The determined values and the predictive model of changes PRT of professional drivers can be useful data in the daily work of health institutions that assess driving ability, in order to identify potentially risky drivers with higher PRT values,, tired and people with initial nervous system damage, prone to traffic injuries and at work, in order to prevent traffic accidents and injuries, as well as to ensure that drivers have the skills necessary for safe driving. The determined values of PRT could be used in the assessment of work ability and in workers in other occupations where a quick and accurate response to a particular stimulus is expected.</p>

<p>Experiment One: The Effect of Noise on Autonomic Arousal</p><p><br></p><p>In response to the growing demand for research that helps us understand the complex interactions between Autonomic Arousal (AA) on behavior and performance there is an increasing need for robust techniques to efficiently utilize stimuli, such as sound, to vary the level of AA within a study. The goal of this study was to look at the impact of several factors, including sound intensity, order of presentation, and direction of presentation on skin conductance level, a widely utilized technique for approximating levels of AA. To do this we had 34 young adults ages 18- 34 listen to a series of 2-minute blocks of a sound stimuli based off a heating, ventilation, and air conditioning system (HVAC). Blocks included 5 single intensity conditions each block differing in 10 dBA steps ranging from 35-75 dBA. We presented blocks in both rising and falling level of intensity, with half the participants hearing them in a rising order first and half in a falling order first. The evidence found by this study suggests that increasing the sound level plays an important role in increasing AA and habituation is an extremely important factor that must be accounted for as it, in the case of typical young adults, quickly dampens the response to stimuli and subsequent stimuli. These findings suggest that researchers can best efficiently maximize the range of AA they can use while keeping their participants comfortable by starting out with the most intense stimuli and proceeding to the less intense stimuli, working with habitation instead of against it.</p><p> </p><p><br></p><p> Experiment Two: The Effect of Autonomic Arousal on Visual Attention</p><p><br></p><p>The goal of this study was to better understand how various levels of autonomic arousal impact different components of attentional control and if ASD-related traits indexed by Autism Quotient scores (AQ) might relate to alterations in this relationship. This study had 41 young adult participants (23 women, 17 men, 1 prefer not to say), ages ranging from 18 to 38 years old. Participants listened to varying levels of noise to induce changes in AA, which were recorded as changes in skin conductance level (SCL). To evaluate attentional control, participants preformed pro and anti-saccade visual gap–overlap paradigm tasks as measures of attentional control. The findings of this study suggest that increased levels of autonomic arousal are helpful for improving performance on anti-saccade tasks, which are heavily dependent on top-down attentional control. Additionally, increases in AQ scores were related to having less of a benefit from increasing levels of arousal on anti-saccade tasks. Additional interactions were also found and are discussed in this paper.</p>

This thesis deals with the possibility to evaluate cognitive and emotional traits and their relations to job positions and functions. The basis is to create a set of tests which could be used during a hiring procedure while deciding among candidates. It also suggests how to classify users based on a set of tests and thereby provide support in choosing the right job. The thesis gives a brief outlook of individually tested traits, describes a proposal of a web application and its implementation, describes implementation of neural network classifier and presents obtained results.

The doctoral thesis analyses driver’s conduct while solving situations associated with crossing of pedestrians across the road in cases of various design of pedestrian crossings and at different conditions. The thesis deepens the knowledge of the human factor impact on the occurrence of a traffic accident involved vehicle and pedestrian and thesis also complements knowledge for the needs of the analysis of traffic accidents, especially in solving the pre collision phase and at assessment of possibilities for collision prevention by involved participants. The thesis deals with driver’s conduct, various models of the conduct as well as the thesis focuses on the visual perception, the process of information processing, the driver’s conduct and the reaction time. In terms of the solution suitable types of experiments were designed and implemented. Based on performed measurements a method of processing and evaluating data on drivers’ conduct was found as well as more significant data set was obtained for a detailed analysis of drivers' conduct in different driving situations. The assessed quantities of drivers' conduct were analysed with respect to the dangerousness of driving situations. For these purposes, the categories of the dangerousness of driving situations were defined (situations completely safe, with increased danger, dangerous and critical), into which the analysed driving situations were subsequently included. To enable the quantification of this classification of situations into the categories of the dangerousness, the coefficient of the dangerousness (so called K) was defined. From the detailed analysis of the obtained data, the limit values of this coefficient were determined, and these were subsequently verified using data from the solution of real traffic accidents. Concurrently the analysis verified the suitability of using this hazard coefficient in the analysis of traffic accidents, especially for a detailed assessment of the possibilities of collision prevention.

Background: Gait initiation is a major issue in Parkinson’s disease (PD). Moreover, the effect of current treatment on motor deficits vary alongside individual differences and disease severity. In some cases, postural instability has been documented as a major side-effect and refractory symptom to dopaminergic medication. Despite these shortcomings, research involving other forms of therapy including deep brain stimulation (DBS) and transcranial magnetic stimulation (TMS), has evidenced the improvement of postural deficits in PD. In this regard, there is a strong rational for the modulation of subcortical brain activity via the application of non-invasive transcranial direct current stimulation (tDCS) to interconnected cortical brain structures. Purpose: Therefore, we sought to determine the effect of tDCS applied to the supplementary motor area (SMA), on gait initiation preparation and performance in PD. Methods: A within subjects repeated measures quasi-experimental design was used to investigate the effects of a 10-minute sham-controlled tDCS intervention. Clinically diagnosed participants (n=12) with idiopathic PD were tested on medication during two sessions that bookended one week. Those who had previously undergone other forms of brain stimulation, had diabetes, severe freezing of gait, or any other neurological or functional limitations that could interfere with gait initiation were excluded from the study. Statistical Analyses/Results: Two-way repeated measures ANOVAs with Bonferroni corrections and a post-hoc analyses when appropriate, revealed a significant reduction in the magnitude of center of pressure (CoP) displacement and velocity in the mediolateral (ML) direction following tDCS. Conclusions: Findings from this study provide insights that may guide scientific research regarding the effects of tDCS on gait initiation among those with PD. Additionally, our work may highlight the importance of ML postural stability for individuals with comorbid and/or pharmacologically induced postural instabilities.