TOWARDS CLASSIFICATION & QUANTIFICATION OF EMOTIONS MEASUREMENT &ANALYIS OF BRAIN POTENTIALS DURING IMAGE PRESENTATION.

No.2281235 Yui Kubota(Supervised by Prof. Masaki Kyoso)
ABSTRACT
Modern society is said to be a stressful society, and stress is closely related to modern people. In
recent years, the number of patients visiting a medical institution for mental disorders has increased
significantly, reaching approximately 2.58 million in 2002 and 6.15 million in 2020. In particular,
the number of patients with depression has increased significantly. According to a survey of 9,936
men and women, a total of 91.3% answered that they Ire feeling stress, which means that almost
everyone has some form of stress. In addition, there are cases where people are actually under agreat deal of stress even if they are not aware of any symptoms. Stress is a troublesome problem
because it is invisible. Thus, the method of ascertaining the state of health in the form ofquestionnaires has become the mainstream. However, questionnaire data is a simplified way ofgrasping the state of stress, so it is a subjective evaluation, and there are limitations in grasping thestate of health in different individual environments. Excessive stress not only increases the r isk ofmental illnesses such as depression, but also causes various diseases such as lo wering immunity,
increasing the risk of infectious diseases, and causing damage to the circulatory and digestivesystems.
I therefore measure 'emotion', which is a physiological response to external stimuli and the recallof internal memories, and estimate 'feelings', which are the subjective, conscious experiences
associated with the occurrence of emotions. By understanding the stress state caused by emotions
and encouraging measures to reduce it, it may lead to the creation of an environment in whichemployees can promote their work in a safe and secure manner. As a specific method, to understandthe stress state caused by an individual's 'emotion', the Electroencephalogram (EEG) is measured
and the Event Related brain Potential (ERP), which indicates the response to a specific event, isquantified. The ERP measurement is thought to automatically detect features and abnormali ties inthe time series data and to be able to estimate objective stress.
The final goal of this research is to establish a real-time stress evaluation method by quantifying"emotions" using ERP, aiming at a stress-free social life for each individual. In order to resolve
inadequacies in the setting of the measurement environmen t and conditions, I added images ofunpleasant emotions as Ill as pleasant ones to the stimulus images and checked whether there weredifferences in the biological reactions.
As a result, positive EEG responses Ire observed in the T3 and T4 regions when the subjectsviewed the cadaveric images, suggesting that they are likely to be related to fear emotion andmemory processing rather than auditory stimuli. Positive potentials Ire also observed on the scalp
of F3 approximately 0.5 s after the presentation of the cadaver image, possibly indicating anattentional or cognitive response. Furthermore, images of dead bodies induce discomfort, which
may be related to emotional processing. On the other hand, images of insects and natural landscapes
also showed low potentials at similar time points, which may act as a focus of attention, as they are
not as terrifying as images of dead bodies. Positive potentials due to image processing are alsopossible. These differences in EEG responses suggest that it may be possible to distinguish between
unpleasant and highly aroused emotions, but as emotions are subjective and vary bet ween
individuals, further research is needed to confirm their repro ducibility.