Jungtae Lee

Stress and EEG

Many people suffer from stress in their everyday life. While there is a close relationship between stress and mental health, psychological stress (and associated emotions such as anger, anxiety, and depression), can also have effects on physical health. Indeed, chronic psychological stress can change the responsiveness of central-peripheral regulatory systems (Fuchs & Fluegee 1995; Fuchs, Uno, & Fluegge 1995), potentially rendering them less efficient or adaptive in terms of supporting health. Conditions such as chronic stress, depression, and anxiety have been found to be associated with abnormal autonomic nervous system (ANS) functioning (Cohen et al., 2000; Hughes & Stoney 2000). Accordingly, stress is one of the major factors contributing to chronic disorders (Decker et al., 1996; Lawrence & Kim 2000). Stress also influences the desire to work, performance at work, and one’s general attitude toward life (NIOSH, 1999). Within the industry sector, higher stress levels and stress-related disease lead to decrease in company performance and increase in medical expenses (Cooper, 1996; Manning, et al., 1996). In 2008 in Korea, there were 1,967 deaths associated with occupational cases. Almost half of these deaths (974, or 49.5%) could be ascribed to heart or brain blood vessel disease (Ministry of Labor, 2008). This is not surprising given that stress is implicated in 75% of all heart and brain blood vessel diseases (Belkic, et al., 2004). It is thus apparent that stress can increase social and economic losses and decrease a country’s competitiveness (Driskell & Salas, 1996). Therefore, precautionary measures to reduce stress and adequate management of this condition are essential for both individual health and the welfare of society at a broader level. This chapter reports on relationships among psychological stress, the EEG (Electroencephalogram), ECG, and salivary cortisol in people suffering from chronic stress. We hypothesized that chronic stress will have negative effects on the central-ANS and physiological responsiveness. There are many bio-signal channels by which stress can be potentially quantified, including ECG, EEG, and the skin conductance response (SCR) (Kohlish & Schaefer 1996; Gevins et al., 1998). Even so, determining the stress level of any given individual can be difficult. Related to this is debate concerning the extent to which the EEG can be used to reliably measure stress. However, this chapter presents data showing that there are significant correlations between EEG measures and other indices of stress, including the ECG and salivary cortisol. Also, it revealed relationships between high beta Source: Convergence and Hybrid Information Technologies, Book edited by: Marius Crisan, ISBN 978-953-307-068-1, pp. 426, March 2010, INTECH, Croatia, downloaded from SCIYO.COM

A Synchronous Multi-Body Sensor Platform in a Wireless Body Sensor Network: Design and Implementation

Background Human life can be further improved if diseases and disorders can be predicted before they become dangerous, by correctly recognizing signals from the human body, so in order to make disease detection more precise, various body-signals need to be measured simultaneously in a synchronized manner. Object This research aims at developing an integrated system for measuring four signals (EEG, ECG, respiration, and PPG) and simultaneously producing synchronous signals on a Wireless Body Sensor Network. Design We designed and implemented a platform for multiple bio-signals using Bluetooth communication. Results First, we developed a prototype board and verified the signals from the sensor platform using frequency responses and quantities. Next, we designed and implemented a lightweight, ultra-compact, low cost, low power-consumption Printed Circuit Board. Conclusion A synchronous multi-body sensor platform is expected to be very useful in telemedicine and emergency rescue scenarios. Furthermore, this system is expected to be able to analyze the mutual effects among body signals.

The Relation between Affective Style of Stressor on EEG Asymmetry and Stress Scale during Multimodal Task

In previous paper, we founded that the affective style of subjects according to an auditory stressor existed. Subjects in the stress group compared to other groups reported a higher level of stress on physiological stress scale. The aim of the current study was to investigate the relation between affective style and stress scale under various stress conditions. This experiment consisted of three sessions such as auditory, movie, and unknot task. We used woman scream, horror movie, and unknot stimuli to evoke stress. We classified the affective style according to task based on EEG asymmetry. The stress scale in stress group was greater than that of other groups for all tasks. Also, a subject who in stress group for specific stimulus was not always in stress group for other stimuli. These results demonstrate that the subjects with the propensity to negative affective style are apt to be stressed.

Brain Response to Good and Bad Design

This paper is about the decision of whether good or bad design is the result of the human brain process. Our research team has used the technique of functional MRI and Electroencephalogram (EEG) to address the question of how the brain answers while subjects viewed different designs. Classifying the good or bad designs, subjects chose a mouse button to decide their perception of good or bad design and we analyzed their patterns of EEG rhythms and fMRI. The results of fMRI showed that the perceptions of different feelings of designs are associated with the frontal lobe and the occipital lobe. After analyzing the EEG by the Event-related brain potentials (ERP) method, we also found that the amplitude of ERP components in perception of bad design is greater and latency is shorter than that of good design. Therefore, the human brain responds sooner and stronger in perception of bad feeling.

Integrated real-time neurofeedback system to raise the frontal lobe activity: Design and implementation

The anti-social behaviors of the people who are characteristic of abnormal action have seriously affected our society. Recent years, with the development of brain science, the features of humans abnormal action have been identified by means of the low frontal lobe activities. However, in many countries, the corresponding systems for identification and treatment are in an insufficient situation. Thus, in this paper, an integrated portable and real-time neurofeedback system assisted by EEG has been developed. The algorithm for this system has been developed and its performance has been verified by the fMRI experiment. Through the experiment, we ensured that the subjects controlled and checked their frontal lobe activities by themselves via the integrated real-time neurofeedback system. And then, the potential humans abnormal action could be not only early detected, but also eased via neurofeedback system. Therefore, we expected that our system can be more benefit to individuals and society.

EEG Analysis of Frontal Lobe Activities by Decision Stimuli

The brain is processing various acts and thoughts of humans. Among the functions of the brain, decision making, reasoning and complex calculation are governed by the frontal lobe. If the FLA (Frontal Lobe Activity) is kept low for a long period of time, human reasoning and decision making are interrupted and anti-social behaviors can emerge which are hardly understandable in view of common people and it can result in serious problems. EEG (Electroencephalogram) was measured by using decision making stimuli which help determine the FLA and, with the index of the measured EEG data, the evoked conditions of subjects were compared and analyzed by utilizing EP (Evoked Potential) and Power Spectrum Analyzing. In the end, by the result of both methods, subjects with apparently low FLA index appeared, and, with the help of the obtained FLA index, critical values determining whether the FLA is in the normal range or not could be presented.

The Effect of an Auditory Stressor, with Respect to Affective Style, on Frontal EEG Asymmetry and ERP Analysis

The aim of the current study was to investigate the effect of an auditory stressor, with respect to affective style, on frontal EEG asymmetry, ERP, and psychological stress. Twenty subjects were tested during the sound of a womans scream and the sound of birds. A greater negative N200 and positive P300 amplitude was exhibited for a womans scream compared with the sound of birds. A shorter N200 and P300 latency was exhibited. Also, a greater right frontal activity was found during a womans scream. Furthermore, the affective style of subjects according to an auditory stressor was found. Subjects in the stress group compared to other groups reported a higher level of stress on Cohens Perceived Stress Scale. These results demonstrate that a womans scream results in relatively greater right frontal activity and psychological stress and serves as an auditory stressor.

A Prototype of Wireless Electrocardiogram Biofeedback Platform and Its Preliminary Evaluation on HRV Alteration in Unconscious Status

In this study, we have developed a prototype of wireless ECG biofeedback platform which consists of three parts: a full-featured signal acquisition platform, a full set of software applications for signal displaying, processing and analysis, and a matlab-based audio generator. Moreover, preliminary experiments on heart rate variability (HRV) have been performed to evaluate the performances of this platform and investigate the changes of HRV in cognitive unconscious status. 23 volunteers were recruited in this experiment, time domain, frequency domain and geometrical parameters of HRV were chosen to analyze in this study. All the results provided a physiological evidence for Positive Psychotherapy theory (PPT) and also demonstrated that this prototype platform was effective for HRV-based biofeedback which may enable emotion self-regulatory and management in daily life.

A wireless EEG monitor system based on BSN node

The development and realization of a portable wireless electroencephalogram (EEG) monitor has become feasible due to the recent active research activities in the area of Wireless Sensor Networks (WSN). In this paper, we propose an EEG monitor design based on a commercially available WSN device, Body Sensor Networks node (BSN node). The device utilizes Zigbee technology and operates on the TinyOS operating system. The EEG signal from subjects is detected and radioed to a PC for monitoring. This study validates our approach and suggests the feasibility of future enhancements.

Design and Implementation of Real-time Blood Pressure Measuring System using Smartphone

Blood pressure may be measured using physiological signals, such as ECG, PTT, and . In this study, we designed and implemented a portable real-time blood pressure measuring system, which can access the Internet simultaneously using the IPv4 / IPv6 protocol. In addition, we presented a model for the calculation of systolic and diastolic blood pressure in a real-time environment. Through clinical experiments on 28 subjects, the blood pressure measuring system was shown to satisfy the requirements of Grade B level of the BHS (British Hypertension Society) certification.