3 research outputs found
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