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In everyday life, the ability to perform two tasks simultaneously, dual task, is an omnipresent issue. There are several factors that can limit an individual’s ability to dual task, such as neurological pathologies, or physical disabilities. A reduced ability to perform dual task activities can result in decreased gait performance, higher risk of falls, a high probability of reduced participation, as well as contributing to a number of deterioration processes in the body. There are numerous situations in which dual tasking is used in therapy, however, there is no consensus regarding what kind of dual task to train in order to have the most effective outcomes. The aim of this systematic review is to investigate the relative effect of motor versus cognitive dual task on brain activity patterns and gait performance. Ten studies were identified in a systematic literature review in order to provide insight into the current status concerning the topic. The results showed high variations of analysed parameters and a very small amount of studies examining motor dual tasks. However, results indicated that cognitive dual tasks had a greater impact on brain activity. In regard to gait performance, no definite answer was found. Given the importance of dual tasks in everyday life and the numerous groups of people experiencing difficulties while dual tasking, the possibilities of adapting dual tasks in therapy should be a topic of future research. / Die Fähigkeit, zwei Aufgaben gleichzeitig auszuführen, auch dual tasking genannt, ist im Alltag ein allgegenwärtiges Thema. Es gibt verschiedene Faktoren, die die Fähigkeit eines Menschen, dual tasks auszuführen, einschränken, wie beispielsweise neurologische Pathologien oder körperliche Behinderungen. Die Verminderung dieser Fähigkeit kann zu abnehmender Gangleistung, erhöhtem Fallrisiko und einer hohen Wahrscheinlichkeit für reduzierte Partizipation führen, sowie folglich zu einer Anzahl an Abnützungserscheinungen des Körpers beitragen. Obwohl es zahlreiche Situationen gibt, in denen dual tasking als Intervention in Verwendung kommt, gibt es keinen Konsens bezüglich der Frage welche Art von Doppelaufgabe trainiert werden soll, um möglichst wirksame Resultate zu erzielen. Das Ziel dieser Arbeit ist es, die relativen Effekte von motorischen dual tasks im Vergleich zu kognitiven dual tasks auf die Hirnaktivität und die Gangleistung zu untersuchen. Zehn Studien wurden in der systematischen Übersichtsarbeit ermittelt, um einen Einblick in den aktuellen Stand der Forschung in diesem Thema zu gewährleisten. Die Ergebnisse zeigten eine Vielzahl an verwendeten Analyseparametern und eine kleine Anzahl an Studien zur Untersuchung von motorischen dual tasks. Trotzdem zeigte sich eine größere Auswirkung von kognitiven dual tasks auf die Hirnaktivität. In Bezug auf die Gangleistung konnte keine eindeutige Antwort gefunden werden. Aufgrund der Wichtigkeit von dual tasks im Alltag und der Vielzahl an betroffenen Personengruppen, die Schwierigkeiten bei der Ausführung jener erleben, sollte die Möglichkeiten der Anpassung von dual tasks auf verschiedene Therapieziele und Patientengruppen Thema für zukünftige Forschung sein.

The objective of this study was to assess low to high levels of Cognitive Workload by measuring heart rate and cortical blood flow in real-time. Four conditions were implemented into a within-subjects experimental design. Two conditions of difficulty and two conditions of trial order were used to illicit different levels of workload which will be analyzed with psychophysiological equipment. Functional Near-Infrared Spectroscopy (fNIRS) has become more prominent for measuring the blood oxygenation levels in the prefrontal cortex of individuals operating in hazardous work environments, students with learning disabilities, and in research for military training. This is due to the fNIR device being highly mobile, inexpensive, and able to produce a high-spatial resolution of the dorsolateral prefrontal cortex during executive functioning. Heart Rate will be measured by an Electrocardiogram, which will be used in concordance with fNIR oxygenation levels to predict if an individual is in a condition that produces low or high mental workload. Successfully utilizing heart rate and blood oxygenation data as predictors of cognitive workload may validate implementing multiple physiological devices together in real-time and may be a more accurate solution for preventing excessive workload.

Speech production not only relies on spoken (overt speech) but also on silent output (inner speech). Little is known about whether inner and overt speech are processed differently and which neural mechanisms are involved. By simultaneously applying electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS), we tried to disentangle executive control from motor and linguistic processes. A preparation phase was introduced additionally to the examination of overt and inner speech directly during naming (i.e., speech execution). Participants completed a picture-naming paradigm in which the pure preparation phase of a subsequent speech production and the actual speech execution phase could be differentiated. fNIRS results revealed a larger activation for overt rather than inner speech at bilateral prefrontal to parietal regions during the preparation and at bilateral temporal regions during the execution phase. EEG results showed a larger negativity for inner compared to overt speech between 200 and 500 ms during the preparation phase and between 300 and 500 ms during the execution phase. Findings of the preparation phase indicated that differences between inner and overt speech are not exclusively driven by specific linguistic and motor processes but also impacted by inhibitory mechanisms. Results of the execution phase suggest that inhibitory processes operate during phonological code retrieval and encoding.

Studies in adults showed differential neural processing between overt and inner speech. So far, it is unclear whether inner and overt speech are processed differentially in children. The present study examines the pre-activation of the speech network in order to disentangle domain-general executive control from linguistic control of inner and overt speech production in 6- to 7-year-olds by simultaneously applying electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS). Children underwent a picture-naming task in which the pure preparation of a subsequent speech production and the actual execution of speech can be differentiated. The preparation phase does not represent speech per se but it resembles the setting up of the language production network. Only the fNIRS revealed a larger activation for overt, compared to inner, speech over bilateral prefrontal to parietal regions during the preparation phase. Findings suggest that the children’s brain can prepare the subsequent speech production. The preparation for overt and inner speech requires different domain-general executive control. In contrast to adults, the children’s brain did not show differences between inner and overt speech when a concrete linguistic content occurs and a concrete execution is required. This might indicate that domain-specific executive control processes are still under development.

In category learning, explicit processes function through the prefrontal cortex (PFC) and implicit processes function through the basal ganglia. Research suggested that these two systems compete with each other. The goal of this study was to shed light on this theory. 15 undergraduate subjects took part in an event-related experiment that required them to categorize computer-generated line-stimuli, which varied in length and/or angle depending on condition. Subjects participated in an explicit "rule-based" (RB) condition and an implicit "information-integration" (II) condition while connected to a functional near-infrared spectroscopy (fNIRS) apparatus, which measured the hemodynamic response (HR) in their PFC. Each condition contained 2 blocks. We hypothesized that the competition between explicit and implicit systems (COVIS) would be demonstrated if, by block 2, task-accuracy was approximately equal across conditions with PFC activity being comparatively higher in the II condition. This would indicate that subjects could learn the categorization task in both conditions but were only able to decipher an explicit rule in the RB condition; their PFC would struggle to do so in the II condition, resulting in perpetually high activation. In accordance with predictions, results revealed no difference in accuracy across conditions with significant difference in channel activation. There were channel trends (p < .1) which showed PFC activation decrease in the RB condition and increase in the II condition by block 2. While these results support our predictions, they are largely nonsignificant, which could be attributed to the event-related design. Future research should utilize a larger samples size for improved statistical power.

No description available.

Unsafe driving habits increase the severity of roadway accidents. The behaviors that are generally associated with unsafe driving are influenced by drivers and their decision to engage in dangerous habits. In order to solve this problem, Departments of Transportation use roadside safety campaigns. To gain a comprehensive understanding of the effectiveness of these campaigns, this research study captured five different metrics of effectiveness to understand what messages are effective and how to target messages to different groups of people. Since reading and interpreting the messages produces cognitive activation among participants, a neuroimaging technology called functional near-infrared spectroscopy (fNIRS) was used to measure neurocognitive activation as a proxy for response. The fNIRS system captures this cognitive activation by measuring change in oxygenated blood (oxy-Hb). An increase in oxy-Hb is a proxy for increased task engagement. The first journal paper provides an understanding of what types of messages are perceived as effective, are misunderstood, are memorable, are considered inappropriate, and cause the greatest increase in cognitive engagement. Overall, drivers perceive messages to be effective at changing behavior, but particular messages are perceived as more effective than others. Messages about distracted driving and driving without a seat belt, messages that are intended to produce a negative emotional response, and messages with statistics are the behaviors, emotions, and themes that are most likely to be perceived to change driver behavior. Messages about distracted driving and messages about statistics are most likely to be remembered by drivers. In general, drivers do not find messages used in safety campaigns to be inappropriate. Drivers elicit more cognitive attention to signs about distracted driving and signs with a humorous emotion. The second journal considers the effectiveness of these messages with different target demographics by further investigating the first journal's results by different dependent variables, including age, gender, and risky driving habits of the participants. In the second study, the results from the first study are further examined to determine if some campaigns are more effective among different demographics of drivers. The behavioral results indicated that females, drivers over 65, low-risk and high-risk drivers, and urban and rural drivers perceive the safety campaigns as more effective. The neurological data revealed that younger drivers had more activation in the ventrolateral prefrontal cortex, an area known for semantics and word processing, which might indicate more cognitive attention to these types of messages. This study provides a unique application of using neuroimaging techniques to understand driver response to safety messages. The recommendations for an effective safety campaign are to use messages about distracted driving, messages with an emotional stimulus, and messages about statistics. Messages about word play and rhyme are recommended for appealing to younger demographics. / Master of Science / Messages like "New year, new you, use your blinker" and "May the 4th be with you, text I will not" are increasingly used to catch drivers' attention. The development and use of these non-traditional safety messages are distinctly different than messages previously displayed on highway signs because the intent of these messages is to modify driver behavior rather than just provide information. Unfortunately, there is little empirical evidence measuring how effective these messages are at changing driver behavior or guidance on how to target messages for specific groups of people. The goal of this study was to understand what types of non-traditional safety messages are effective and how to target these messages to different target audiences. Roadway collisions are made more severe when the cause of the incident involves dangerous driving habits, such as distracted, impaired, or aggressive driving. The problem is made even more severe by the fact that the habits that make driving dangerous are affected by the driver's decision to engage in risky driving behavior. The solution to this problem is to gain an understanding of driver preferences and response, a research effort this study will address. Reading and interpreting the messages produces cognitive activation among participants. The study uses functional near-infrared spectroscopy (fNIRS), which allows researchers to capture this cognitive activation by measuring change in oxygenated blood (oxy-Hb). This provides not only the ability to gain a more detailed understanding of driver response, but the ability to triangulate this with what drivers perceive as effective in changing driver behavior. In the first study, the participants felt that campaigns targeting distracted driving, messages with a negative emotion, and campaigns about statistics were significantly more effective at changing driver behavior compared to other behaviors, emotions, and themes. The neurological data revealed that drivers respond more to campaigns about distracted driving. However, the neurological data indicates that humorous messages and messages that fit under the theme word play and rhyme elicit a greater cognitive response. The second study furthers the first study and revealed that females, drivers over 65, low-risk and high-risk drivers, and urban and rural drivers perceive the safety campaigns as more effective. The neurological data revealed that younger and older males and older high-risk drivers respond with greater peak oxy-Hb when compared to other groups of people. This study advances the applicability of fNIRS in traffic related studies.

Civil infrastructure serves as the driving force behind the evolution of a safe, sustainable, and efficient environment. However, the way information about civil infrastructure has been communicated to the public has been insufficient. Since every human is intrinsically different, designing, and dispersing information about civil infrastructure that accommodates everyone, while also being direct and concise has been a challenge for policymakers and other federal, state, local, and tribal civil engineering stakeholders. Though there has been a plethora of research conducted on message design and communication in other disciplines, little research has been done in the US that focuses on designing more accessible, actionable civil infrastructure messages. The objective of this research was to investigate how to improve the accessibility of civil infrastructure messages and communication infrastructure to enhance the public's ability to make daily infrastructure decisions. This research study utilized quantitative and qualitative methods to analyze and discuss various ways that civil infrastructure messages can be improved. Results from this study are based on the exploration of three different ways in which civil infrastructure messaging can be improved: policy, transportation/roadway safety, and emergency response. Data sources include eight publicly accessible energy policies from 1978-2022, a publicly available dataset of more than 75 thousand WEAs, and a dataset retrieved from Shealy et al. (2020), which collected data on 300 Virginia drivers in both rural and urban areas. A descriptive policy analysis and Flesch-Kincaid readability test were conducted to historically analyze energy policies and understand their accessibility impacts for research question 1; a brain activation network analysis was conducted and nodal network measures (i.e., network density, degree centrality) were used to investigate the cognitive response Virginia drivers had for various types of non-traditional traffic safety messages for research question 2; and sentiment analysis, emotion detection analysis, as well as a two-phased qualitative coding analysis (i.e., in-vivo coding, focused coding) were conducted to investigate how WEAs can be better designed to increase public attention and engagement for research question 3. The findings from this study demonstrate how emotional content that is present in tweets authored by community members affected by the natural disaster event can be incorporated into the WEA template. The findings from research question 1 identified potential issues with accessibility and energy policy. Also, the findings from this study describe the content included in the parallel documents that federal agencies use to communicate the most important information of a policy. The findings from research question 2 demonstrate that while the various types of non-traditional traffic safety messages produced variances in cognitive response, messages that included negative emotional content or statistics should be further explored on their impact on evoking safer driving behaviors. The findings from research question 3 reported on how emotional content could be incorporated into the template design of WEAs. The implications from this dissertation provide valuable insights for policymakers, civil engineers, transportation engineers, and emergency response stakeholders and the conclusions set the stage for future research to improve the design of more accessible civil infrastructure messages. / Doctor of Philosophy / Civil infrastructure messages are used daily, but improper design can make them difficult to understand or to continue to use over long periods of time. Also, every human is different and interprets information about civil infrastructure, which adds a level of difficulty to designing effective civil infrastructure messages. Though there has been a lot of research on the effectiveness of civil infrastructure, little research has used a human-centered design approach to improve civil infrastructure messages. This study analyzes three different ways to improve civil infrastructure messages: policy, traffic safety, and emergency response. We used publicly available energy policies from 1978-2022, data collected by co-authors from Shealy et al. (2020) to analyze the cognitive response of 300 Virginia drivers to various types of non-traditional traffic safety messages, a publicly available dataset of more than 75 thousand Wireless Emergency Alerts sent by FEMA, and a publicly available data set of more than 9.1 thousand tweets about Hurricane Harvey. To analyze this data, this research study utilized various methods to understand how easy policies are to read, to understand how the brains of Virginia drivers respond to different types of non-traditional traffic safety messages and to identify the differences between tweets and WEAs. Results from this study suggest that parallel documents should be published alongside energy policies to help the public understand the main points of the policy, establish a readability metric to use for all energy policies, continue to investigate non-traditional traffic safety messages that included negative emotional content or statistics, measure the brain activation and observe long-term driving behaviors, use more negative emotional content in templated WEAs, and use social media data to better design templated WEAs. The findings reported from this study can be beneficial for various types of civil infrastructure stakeholders such as policymakers, utilities, US State Departments of Transportation, FEMA, alerting officials, and the public to further explore ways in which the language of civil infrastructure messages can be improved to address accessibility issues with energy policy, traffic safety, and emergency response to the public.

Thèse de doctorat présentée en vue de l'obtention du doctorat en psychologie (Ph.D). / L'enfance et l'adolescence sont des périodes uniques de la vie où les changements neuronaux favorisent l'établissement de réseaux cérébraux matures et le développement des capacités intellectuelles. Le langage est un domaine cognitif qui est, non seulement essentiel pour la communication interhumaine, mais qui contribue également au développement de nombreuse capacités et prédit de manière significative la réussite académique. Les régions cérébrales frontotemporales sont des régions clés du réseau langagier du cerveau. Il a été démontré que les neuropathologies telles que l'épilepsie des lobes frontal et temporal (ELF et ELT) interfèrent avec le développement des réseaux cérébraux du langage et provoquent des circuits cérébraux aberrants. Les patrons exacts de réorganisation des réseaux cérébraux fonctionnels ne sont toutefois, pas entièrement compris et l'association avec le profil neuropsychologique reste spéculative. Par conséquent, l'objectif principal de cette thèse est d'accroître la compréhension des altérations du réseau langagier et d'améliorer les connaissances de l'association de l'architecture du réseau et des capacités cognitives chez les enfants et les adolescents avec ELF ou ELT. La présente thèse est composée de trois articles scientifiques, les deux premiers présentant des travaux méthodologiques qui ont permis d'optimiser les méthodes appliquées dans le troisième article, l'étude empirique principale menée auprès d'enfants avec ELF et ELT. Le premier article présente le bilan neuropsychologique pédiatrique comme un outil important pour estimer les capacités cognitives et dresser un profil cognitif avec ses forces et ses faiblesses. Dans le deuxième article, l'analyse factorielle parallèle (PARAFAC) est présentée et validée comme une nouvelle technique employée pour corriger les artefacts de mouvement qui contaminent le signal hémodynamique évalué par la spectroscopie fonctionnelle proche infrarouge (fNIRS). Une meilleure qualité du signal permet une interprétation fiable de la réponse cérébrale en plis de déduire des métriques d'organisation du réseau cérébral. Le troisième article consiste en une étude empirique, où le traitement cérébral du langage, est comparé entre des enfants avec ELF et ELT, et des pairs neuroptypiques. Les schémas de connectivité fonctionnelle indiquent que le groupe de patients présente moins de connexions intra-hémisphériques dans l'hémisphère gauche et entre les hémisphères, et des connexions accrues dans l'hémisphère droit par rapport au groupe témoin. Les mesures de l'architecture du réseau révèlent en outre une efficacité de traitement local plus élevée dans l'hémisphère droit chez les enfants atteints de ELF et ELT par rapport aux enfants en bonne santé. L'architecture du réseau local de l'hémisphère gauche et la capacité intellectuelle globale dans le groupe de patients sont négativement liées, tandis que dans le groupe contrôle, aucune association de ce type n'est identifiable. Ces résultats suggèrent que la réorganisation du réseau de langage chez les enfants avec ELF ou ELT semble dans certains cas soutenir un meilleur résultat cognitif, soit lorsque l'efficacité du traitement local dans l'hémisphère gauche est diminuée. Au contraire, une plus grande efficacité de traitement local semble être une caractéristique d'un réseau de langage cérébral associé à de moins bonnes capacités cognitives. Les travaux de recherche de cette thèse de doctorat fournissent des lignes directrices pour l'utilisation de l'évaluation neuropsychologique pédiatrique, à la fois dans un contexte clinique et scientifique. L'introduction de PARAFAC pour corriger les artefacts de mouvement dans le signal fNIRS est un ajout important au pipeline de prétraitement qui permet d'augmenter la qualité du signal pour une analyse ultérieure. De futurs projets pourront s'appuyer sur cette validation initiale et étendre l'utilisation de PARAFAC pour les analyses du signal fNIRS. Sur cette base méthodologique solide, le travail empirique confirme l'incidence accrue de circuits cérébraux aberrants liés au traitement du langage chez les enfants atteints de ELF et de ELT, et soutient en outre l'efficacité du réseau local en tant que déterminant clé de l'impact de la plasticité cérébrale précoce sur les capacités cognitives. Afin de mieux comprendre les altérations du réseau en réponse aux neuropathologies et leur impact, des études avec des échantillons plus grands et de différents groupes d'âge, devraient étudier plus spécifiquement le rôle des facteurs cliniques (e.g., le type d'épilepsie, la latéralisation de l'épilepsie, le contrôle des crises, etc.) et aborder leurs influences sur le développement. À long terme, cela augmentera le pronostic des phénotypes cliniques chez les patients pédiatriques atteints de ELF et de ELT, et offrira des opportunités d'interventions précoces pour soutenir un développement typique. / Childhood and adolescence are unique periods in life where neuronal changes support the establishment of mature brain networks and the development of intellectual capacities. Language is one cognitive domain that is not only an essential part of inter-human communication but also contributes to the development of other capacities and significantly influences academic achievement. Frontotemporal brain areas are key regions of the brain's language network. Neuropathologies such as frontal and temporal lobe epilepsies (FLE and TLE) have been shown to interfere with developing brain language networks and cause aberrant cerebral circuits. The exact patterns of functional brain network reorganization are not fully understood and the association with the neuropsychological profile remains speculative. Therefore, the main objective of this thesis was to increase comprehension of language network alterations and enhance the knowledge on the association of network topology and cognitive capacities in children and adolescents with FLE or TLE. This thesis consists of three scientific articles, with the first two presenting methodological work that allowed for the optimization of the methods applied in the third article, which is the main empirical study conducted on children with FLE and TLE. The first article presents the pediatric neuropsychological assessment as a valuable tool to estimate cognitive capacities and draw a cognitive profile with strengths and weaknesses. In the second article, parallel factor analysis (PARAFAC) is presented and validated as a novel technique to correct motion artifacts that contaminate the hemodynamic signal assessed with functional near-infrared spectroscopy (fNIRS). A better signal quality is the basis for a reliable interpretation of the cerebral response and derive metrics of brain network organization. The third article consists of an empirical study where cerebral language processing is compared between children with FLE and TLE, and neuroptypical peers. Patterns of functional connectivity indicate that the patient group demonstrates fewer intra-hemispheric connections in the left hemisphere and between hemispheres, and increased connections within the right hemisphere as compared to the control group. Metrics of network architecture further reveal a higher local processing efficiency within the right hemisphere in children with FLE and TLE compared to healthy peers. Local network architecture of the left hemisphere and the overall intellectual capacity in the patient group is negatively related, while in the control group no such association is identifiable. These findings suggest that language network reorganization in children with FLE or TLE in some cases seems to support a better cognitive outcome, namely when local processing efficiency in the left hemisphere is decreased. On the contrary, a higher local processing efficiency seems to be a characteristic of a brain language network that goes along with worse cognitive capacities. The research work of this doctoral thesis provides guidelines for the use of pediatric neuropsychological assessment both in a clinical and scientific context. The introduction of PARAFAC to correct motion artifact in the fNIRS signal is an important add-on to the preprocessing pipeline that allows to increase signal quality for subsequent analysis. Future projects will be able to build on this initial validation and extend PARAFAC's use for fNIRS analysis. On this solid methodological foundation, the empirical work confirms the increased incidence of aberrant brain circuits related to language processing in children with FLE and TLE, and further supports local network efficiency as a key determinant of the impact of early brain plasticity on cognitive capacities. In order to further understand network alterations in response to neuropathologies and their impact, studies with larger samples sizes and different age groups should further investigate the specific role of clinical factors (e.g., epilepsy type, epilepsy lateralization, seizure control, etc.) and address developmental influences. Ultimately, this will increase prognosis of clinical phenotypes in pediatric patients with FLE and TLE, and offer opportunities for early interventions to support a healthy development.