Spontaneous synchronization to speech reveals neural mechanisms facilitating language learning

We introduce a deceptively simple behavioral task that robustly identifies two qualitatively different groups within the general population. When presented with an isochronous train of random syllables, some listeners are compelled to align their own concurrent syllable production with the perceived rate, whereas others remain impervious to the external rhythm. Using both neurophysiological and structural imaging approaches, we show group differences with clear consequences for speech processing and language learning. When listening passively to speech, high synchronizers show increased brain-to-stimulus synchronization over frontal areas, and this localized pattern correlates with precise microstructural differences in the white matter pathways connecting frontal to auditory regions. Finally, the data expose a mechanism that underpins performance on an ecologically relevant word-learning task. We suggest that this task will help to better understand and characterize individual performance in speech processing and language learning

Collection and processing of data from wrist wearable devices in heterogeneous and multiple-user scenarios

Over recent years, we have witnessed the development of mobile and wearable technologies to collect data from human vital signs and activities. Nowadays, wrist wearables including sensors (e.g., heart rate, accelerometer, pedometer) that provide valuable data are common in market. We are working on the analytic exploitation of this kind of data towards the support of learners and teachers in educational contexts. More precisely, sleep and stress indicators are defined to assist teachers and learners on the regulation of their activities. During this development, we have identified interoperability challenges related to the collection and processing of data from wearable devices. Different vendors adopt specific approaches about the way data can be collected from wearables into third-party systems. This hinders such developments as the one that we are carrying out. This paper contributes to identifying key interoperability issues in this kind of scenario and proposes guidelines to solve them. Taking into account these topics, this work is situated in the context of the standardization activities being carried out in the Internet of Things and Machine to Machine domains.Xunta de Galicia | Ref. GRC2013-00

The Dynamics of Central-Peripheral Stress Responses after Acute Psychosocial Stress: a Multimodal Perspective

An acute stress response is a complex interaction of central and peripheral psychophysiological systems with unique temporal characteristics. Interestingly, the interaction represents a unique temporal characteristic. Investigating the dynamics of both brain and body signals during and after an encounter with a stressor allows us to understand the underlying principle of the acute stress response, which has been shown to be atypical in various psychiatric disorders. However, a detailed understanding of stress response is rarely investigated. Therefore, this thesis investigates two major approaches for understanding the acute stress response dynamics using simultaneous electroencephalography (EEG)-photoplethysmographyfunctional magnetic resonance imaging experiments in 39 subjects before and after the ScanStress task. The EEG-derived vigilance indexes reveal a continuous decline at rest. Given the role of alertness in an efficient stress response, the effects of acute stress induction on EEG-derived vigilance metrics are of interest. Therefore, the first approach uses the dynamic analysis of psychophysiological stress responses after the acute psychosocial stress induction. The first study investigates the carry-over effect of acute psychosocial stress on vigilance and its modulation by the multicomponent over-thecounter drug neurexan, which has been shown to modulate the neuroendocrine stress response. By using dynamic analysis, six vigilance scores were calculated every two minutes before and after the stress induction during the resting state. The study revealed that stress delays the continuous decline of vigilance at rest. In addition, the stress-induced increase in mean vigilance levels at rest was correlated positively with the levels of perceived stress during the last month. In addition, the mean vigilance level exhibited a decrease after neurexan treatment compared to placebo intake. Heart rate variability (HRV) can be viewed as an indicator of how well the adaptive regulation system in the brain reacts the peripheral environment. However, the relationship between the HRV and functional connectivity patterns in the brain networks in stressful situations is rarely investigated. Therefore, the second approach uses the multimodal approach to examine the interaction between different stress response systems. The study investigated the temporal association between HRV and FC between the three core brain networks, namely the central executive network, salience network, and default mode network at baseline and after the psychosocial stress induction. In this study, the functional connectivity between three core brain networks and the HRV was examined by taking 60s window length. Furthermore, the temporal association between HRV and functional connectivity was investigated. A significant association was found between HRV and default mode network-central executive network functional connectivity at rest, which was significantly reduced after acute stress induction compared to baseline. These findings suggest that HRV cofluctuates with the core brain networks selectively depending on the stress conditions. In summary, acute psychological stress affects brain dynamics by exhibiting a delay in the continuously declining vigilance and keeping the brain in a more alert state even after the stressor disappears. Furthermore, the results suggest that EEG-derived vigilance metrics index not only stress-response but also the temporal dynamics of vigilance regulation. It can serve as a potential biomarker for the diagnosis and prognosis for stress-related disorders disrupting temporal characteristics of stress response dynamics and showing atypical stress response. In addition, the study revealed that stress affects the interactions among the core large-scale functional networks and physiological dynamics of the heart. The dynamic adaptation of the resources is crucial in a stressful situation; therefore, the stress alters the interaction between the brain and heart. The perturbation in this interaction may play an important role in developing and maintaining stress-related disorders. The thesis work provides novel insights and an understanding of the central and peripheral stress response dynamics, which show a huge potential for the diagnosis, prognosis, and therapeutic planning of individuals with neuropsychiatric disorders

Green exercise: Combined influence of environment and exercise to promote wellbeing

Exercise participation is linked to mental health and wellbeing. However, we need to identify optimal settings for promoting exercise-associated wellbeing outcomes, and for promoting exercise adherence. The literature suggests environmental settings may be important. The aim of this thesis was to rigorously test influences of environmental settings on exercise-related wellbeing outcomes. These over-arching research questions guided the experimental chapters: (i) is there an optimal green exercise environment for promoting wellbeing? (ii) When exercise is controlled, are findings consistent with previously reported psychological outcomes? (iii) Do environmental settings influence social outcomes of exercise or intentions to repeat exercise behaviours? Via field-based sampling, Chapter 3 found large proportions of affective benefits were universally obtainable across four typical green exercise environments, and suggested that the processes component of green exercise warranted further investigation; however, this method lacked control. Chapter 4 used laboratory-based methodology to control exercise and isolate the visual environment; consistent with both theory and previous research, nature environments facilitated wellbeing-related attention restoration. However, this method did not provide an accurate multisensory experience, therefore lacking ecological validity. Chapter 5 investigated methodologies for controlling the exercise component, comparing wellbeing-related outcomes of indoor versus outdoor exercise. This was important because previous research had not rigorously controlled exercise, therefore potentially confounding its findings. Results for environment-related exercise differences and affective outcomes were inconclusive. Chapter 6 merged laboratory-based methods with the indoor versus outdoor exercise paradigm, ensuring control and ecological validity. Environmental setting did not influence perceived exertion or mood; green settings promoted attention restoration and social interaction; for green exercise, social interaction predicted exercise intentions. Green exercise promotes wellbeing improvements; environmental influences on affective outcomes may be contributed to by differences in exercise performed. Independent of exercise differences, green environments promote attention restoration and social interaction during exercise, which may in turn influence exercise intentions

OPTIMIZATION OF TERMINAL LAYOUTS: AN ANALYTICAL AND SIMULATIVE APPROACH BASED ON GENETIC ALGORITHMS

2012/2013Every day millions of pedestrian move with different needs and objectives through spaces each of them with its functional specifications. An accurate design or revisiting of transport terminals, as for example railway stations, underway stations, airports, as well as complex buildings, open spaces and a deep analysis of public events with relevant pedestrian flows, would improve its usability at users benefit. To reach this goal is necessary a careful integration among architecture, engineering needs and transport disciplines, that, starting from the study of users behavior and pedestrian dynamics, provides the fundamental elements to be considered during design stage to ensure a major level of service. In literature nothing much is known about the optimal dimension of pedestrian transportation terminals. The aim of this study is to develop a methodology to size the functional terminal layouts, by the integration of analytical and simulative models submitted to generic algorithms, taking into account the dynamics and flows generated inside the terminals. In order to obviate the lack of requisite data for models calibration, validation and verification, as well as testing the process developed, an algorithm for data acquisition has been elaborated. It has a dedicated graphic interface, which allows to reveal the pedestrian dynamics and consequently to generate database; with these data is possible to obtain statistical and behavioral indicators about pedestrians detected. The use of analytical models, both to define the sizing of facilities inside the terminals and to model the user behavior during their paths, allows to define an objective function able to represent the performances of the terminal functional layout. Defined the dimensional ranges of each functional element inside the layout according a specific Level of Service, performed a design of experiments methodology and applied genetic algorithms to minimize the objective function, it is possible to obtain a set of optimal solutions for the terminal configuration sizing, in coherence with flows and dynamics generated inside the terminals itself. A further simulative approach, based on the application of the social force algorithm, allows, through quantitative and qualitative parameters, to identify the best solution(s) inside the domain previously identified with genetic algorithm application. Starting from the motivation that inspired this work, analyzed the existing literature and the main methods for data acquisition, it will be introduced the algorithm for the automatic acquisition of data and pedestrian database generation. The application of this tool will be illustrated in order to manifest the potentiality of the instrument same. Subsequently introduced the tool developed for the definition of the characteristic elements sizing and the model chosen for the correct estimation of pedestrian travel times, it will be explored the structure of the objective function aimed to identify the right trade-off between infrastructure and pedestrian costs. Finally, the application of genetic algorithms, resulting in the identification of Pareto front, generates the domain of optimal solutions to sift through the simulation approach. The developed methodology reveals a flexible and simple instruments, but, at the same time, accurate in the resolution of the problems for which has been structured. The potential of the developed methodology is highlighted in the course of the work thanks to a case of study.Ogni giorno milioni di pedoni si muovono con esigenze ed obbiettivi diversi in contesti differenti, ognuno dei quali con le sue caratteristiche tecniche funzionali. Un’attenta progettazione o rivisitazione dei terminali di trasporto, quali stazioni ferroviarie, metropolitane, aeroporti, così come degli edifici complessi, degli spazi aperti ed una corretta disamina degli eventi pubblici con flussi pedonali rilevanti, consentirebbe di migliorarne la fruibilità a beneficio dell’utenza. Per raggiungere tale obiettivo risulta necessaria un’attenta integrazione tra esigenze architettoniche, ingegneristiche e le discipline trasportistiche, le quali, partendo dallo studio comportamentale degli utenti e dalle dinamiche pedonali, forniscano gli elementi fondamentali da tenersi in considerazione nella fase di progettazione per garantire un maggiore livello di servizio. Riscontrata in letteratura una carenza di approcci finalizzata alla determinazione del miglior layout funzionale dei terminali, attraverso l’integrazione di modelli analitici e simulativi sottoposti ad algoritmi genetici, è stata sviluppata una metodologia che, coerentemente con le dinamiche e i flussi che all’interno dei terminali stessi si generano, mirasse al dimensionamento ottimo dei terminali di trasporto pedonale. Per ovviare alla mancanza di dati necessari per i processi di calibrazione, validazione e verifica dei modelli così come per testare il metodo sviluppato è stato innanzitutto elaborato un algoritmo per l’acquisizione di dati, con interfaccia grafica dedicata, che consente di rilevare le dinamiche pedonali, generare database e conseguentemente ricavare dati statistici e comportamentali dei pedoni. L’utilizzo di modelli analitici, sia per l’identificazione dei range dimensionali degli elementi caratteristici presenti all’interno dei terminali che per la modellizzazione del comportamento degli utenti, permette di definire una funzione obbiettivo che rappresenti le performances dei layout funzionali dei terminali. Attraverso design of experiments calibrati sui range dimensionali dei singoli elementi funzionali presenti all’interno dei terminali e la successiva applicazione degli algoritmi genetici finalizzati alla minimizzazione della funzione obiettivo, è possibile definire un insieme di soluzioni ottime per il dimensionamento dei terminali, in coerenza con i flussi e le dinamiche che in esso si generano. Un’ulteriore approccio simulativo, basato sull’applicazione dell’algoritmo delle forze sociali, consente, attraverso la valutazione di parametri quantitativi e qualitativi, di identificare la/e miglior soluzione/i all’interno del dominio di soluzioni precedentemente identificate con l’applicazione degli algoritmi genetici. A partire dall’esplicitazione delle motivazioni che hanno alimentato questo lavoro, analizzata la letteratura esistente e le principali metodologie per l’acquisizione dati, verrà introdotto l’algoritmo per l’acquisizione automatica dei dati pedonali e la generazione di database contenenti i profili degli utenti rilevati. A seguire troverà spazio l’applicazione di questo strumento per manifestarne le potenzialità. Successivamente, introdotto il tool sviluppato per la definizione dei range dimensionali degli elementi caratteristici e il modello scelto per la corretta stima dei tempi di percorrenza pedonali, verrà esplorata la strutturazione della funzione obiettivo finalizzata alla ricerca del giusto trade off tra costi infrastrutturali e pedonali. Infine, l’applicazione degli algoritmi genetici, risultanti nell’identificazione del fronte paretiano, genererà il dominio di soluzioni ottime da vagliare attraverso l’approccio simulativo. La metodologia sviluppata si è rivelata uno strumento flessibile ed agevole, ma, allo stesso tempo, puntuale nel risolvere i problemi per cui è stata ideata. Le potenzialità della metodologia sviluppata vengono messe in risalto nel corso dell’elaborato grazie ad un caso di studio condotto.XXVI Ciclo198