A Study of the Classification of Motor Imagery Signals using Machine Learning Tools

In this paper, we propose a system for the purpose of classifying Electroencephalography (EEG) signals associated with imagined movement of right hand and relaxation state using machine learning algorithm namely Random Forest Algorithm. The EEG dataset used in this research was created by the University of Tubingen, Germany. EEG signals associated with the imagined movement of right hand and relaxation state were processed using wavelet transform analysis with Daubechies orthogonal wavelet as the mother wavelet. After the wavelet transform analysis, eight features were extracted. Subsequently, a feature selection method based on Random Forest Algorithm was employed giving us the best features out of the eight proposed features. The feature selection stage was followed by classification stage in which eight different models combining the different features based on their importance were constructed. The optimum classification performance of 85.41% was achieved with the Random Forest classifier. This research shows that this system of classification of motor movements can be used in a Brain Computer Interface system (BCI) to mentally control a robotic device or an exoskeleton.

Assessing Momentary States of Relaxation: The Relaxation State Questionnaire

Stress is ubiquitous in everyday life and hazardous for mental and physical health. To prevent or ameliorate stress-related disease, approaches such as relaxation exercises aim to counteract stress by inducing short-lasting states of relaxation. Critically, current assessments capture the mid- and long-term consequences of relaxation but are unable to quantify these states of relaxation. To address this problem, we developed the Relaxation State Questionnaire (RSQ). We assessed the item properties, reliability, and validity of the questionnaire in an online study. Construct validity was examined through correlations with the Perceived Stress Questionnaire (PSQ; Fliege et al., 2005). An exploratory factor analysis revealed four factors capturing the momentary state of muscle tension, sleepiness, cardiovascular activity, and general relaxation. The items had high loadings on their factors and the reliability and construct validity of the RSQ were both high. These findings establish the RSQ as a tool to measure states of relaxation. As such, the RSQ opens up investigations of the immediate effects and effectiveness of relaxation exercises.

Effects of Guided Imagery, Zikar Azkar, and Priming Technique on Stress and Relaxation Level Among University Students

This study was conducted to find out the effectiveness of the three relaxation techniques which are Guided Imagery, Zikar Azkar, and Priming Technique on coping with stress and on the relaxation state of an individual. The total sample included 51 university students in which each group had 17 female students. Smith Relaxation States Inventory 3 and Perceived Stress Scale were used to measure relaxation states and perceived stress levels of the participants. The Smith Relaxation States Inventory 3 has two subscales. The State Version (SRSI3) measures the current relaxation state of a person and the Disposition Scale (SRSI3d) evaluates how often individuals experience worries, stress, and negative emotions. The participants were randomly assigned to three groups. The questionnaires were administered before and after four weeks to the participants. The findings of the study showed that all the three relaxation techniques were effective in reducing stress, however, the results show that Zikar Azkar was more effective than Guided Imagery and Priming Technique. It was also found that Zikar Azkar was also effective in improving the relaxation state of individuals besides being more effective than Guided Imagery, and Priming Technique in reducing negative emotions and stress.

Neuroergonomic Stress Assessment with Two Different Methodologies, in a Manual Repetitive Task-Product Assembly

Emotions are a fundamental part of mental health and human behavior. In the workplace, optimal performance of employees is necessary for productivity enhancements and its relation to the quality of a manufacturing product, therefore leading a company to advantages and competitiveness. This means that the workplace staff must remain in a neutral or a calm emotional state, for an adequate job performance. When an operation is not pleasant or the same task is carried out for a long period of time (repetitive), it can cause negative emotions such as stress, and this will have repercussions in poor work performance. The purpose of this research is, by means of an electroencephalogram (EEG), to identify the stress in the repetitive assembly of a manufacturing product. To measure brain waves, the Emotiv Epoc equipment was used and a manufacturing line was designed, divided into three workstations, where the assembly of product comprising a LEGO car was carried out within a manual repetitive approach. The appearance of stress was determined by employing two different methodologies, the prefrontal relative gamma marker (RG) and the valence, arousal, and dominance (VAD) emotional categories. The results obtained from the first methodology, corresponding to the RG marker, displayed a significant more change between the relaxation state and the product assembly carried out at 70% of the standard time (ST). A less significant change was observed between the relaxation state and the product assembly carried out at 100% ST, thus signaling the presence of stress. Additionally, the results from the VAD methodology resulted in moderate and low levels of stress, when the product assembly was carried out at 70% and 100% standard time, respectively.

The effect of an image of watchful eyes on the evaluation of the appearance of food

It is known that an eye-like image promotes generosity. It is also known that the evaluation of the visual deliciousness of food is improved in the presence of an emotionally positive stimulus. The purpose of the present study was to examine whether the presence of open eyes (OPEN) causes generous behavior altering the evaluation of the visual deliciousness of food, and how the images of open and closed eyes (CLOSED) affect human emotions. Seventeen women participated in the present study. A picture of food was presented on a computer screen, and the participants predicted and evaluated its visual deliciousness. An image of OPEN or that of CLOSED was presented simultaneously with a picture of food. There was a significant difference between the OPEN and CLOSED conditions, as demonstrated by the scores on a nine-point Likert scale for visual deliciousness; the ratings in the OPEN condition were significantly higher than those in the CLOSED condition (p = 0.004). There was no significant difference in the image of watchful eyes for the perceived relaxation state; the ratings in the OPEN condition were not significantly higher than those in the CLOSED condition (p = 0.716). The results of the present study revealed that the evaluation of the visual deliciousness of food based on its appearance was likely due to the presence of an image of open watchful eyes, increasing the perceived visual deliciousness of the food without any changes in the participants’ emotions.

Galvanic Skin Response (GSR) signals reduced from Gayatri Mantra fire oblations during Yagya

Galvanik skin response (GSR) is the measurement of the autonomic activation of sweat glands in the skin for depicting stress, emotional arousal and relaxation pattern. Yagya is a vedic ritual composed of various rhythmic chanting of mantra. Since Vedic times, it is widely and traditionally performed for various purposes including peace, happiness and mental and physical wellbeing. Hence, the present study attempted to explore the GSR pattern during Yagya ritual. The study measured GSR pattern in the 12 participants during Yagya ritual and evaluated changes in GSR signal during chanting of different mantra of the Yagya ritual. The result indicated GSR signal during Yagya ritual followed a defined pattern. Median GSR signals was decreased after fire ritual i.e. later-half of the Yagya compared to first-half of the Yagya (median fold change decrease 1.38; n=12; p=0.0010). Interestingly, this decrease in GSR achieved significantly during Gayatri Mantra fire sacrifice (median fold change decrease 1.35; n=12; p=0.0024), and remained low compared to that of in starting phase of Yagya ritual, indicating significance of Gayatri mantra in Yagya ritual to achieve relaxation state. Overall, the study indicated that vedic traditional ritual of Yagya potentially have a positive effect on our emotions for achieving relaxation.

Effect of eye massaging device towards brain rhythms

This study aimed to examine the effectiveness of the eye massaging device in promoting mind relaxation state based on alpha rhythm in brain. This study has been conducted involving 35 participants whose their brain signals were captured by an electroencephalography (EEG) machine whilst they undergoing resting state, eye massaging session and visual tasks designed to induced stress. The signal is analyzed using Discrete Wavelet Transform (DWT) and the major concern of the study, relative power of alpha was extracted from channel point O1 and O2. T-test analysis used to validate the differences of relative alpha power produced before and after using the device. Based on the results, the average values of relative alpha power collected for EEG signals before using the eye massaging device has been increased for both channel (O1: before = 17.601, after = 19.765, O2: before = 12.577, after = 14.783) with an increment of 12.29% and 17.54% respectively. However, there is no enough evidence to prove that using the device give positive effect on improving participant’s relaxation state as there is only have 51.5% and 58.4% chances that the device might worked on mind relaxation state.