Searching for connections between expression and emotion via the dual approaches of psychology and physiology

Communication among people is not simply an exchange of information using words. Visual information is also taken in, including gestures and facial movements. Especially, information from reading faces is thought to be extremely important in communicating.

Specializing in emotional psychology and psychophysiology, Associate Professor Fujimura has made steady progress on elucidating human expressions. “ Psychology of emotion aims to clarify the triggering mechanisms and functions of emotions, including happiness, anger, and affect. Meanwhile, the field of psychophysiology studies relationships between the mind and the body as a means of discovering the structure and behavior of the mind. For example, the pulse rate of most people increases when they have to make a speech. We try to understand this mental state called ‘nervous tension’ using such physiological changes. We are especially moving forward on research that seeks to uncover relationships between expressions and feelings in communication, and to find out how people ‘read’ the expressions of others.”

Using “congruent facial expression” to determine the role of expressions in communication

“When you smile, the whole world smiles with you” describes an experience familiar to everyone: smiles are naturally “contagious.” This kind of “facial mimicry” is known by various terms in the scholarly world, including “congruence of facial expression.” This “congruence” （similarity） in the response to people’s expressions has been a long-term theme in Dr. Fujimura’s research. It is well-known from previous research that cheek muscles move in response to a smile to form a similar smile, while the muscles that control the eyebrow areas move to a frowning position when one encounters an angry person. Dr. Fujimura thought that changes in facial expressions might be dependent on the level of trust one has in the other person. “My idea was that mimicry would differ depending on whether one wanted to forge a better relationship with the other person. So, I started by looking at the degree of trustworthiness, to see how this social factor of interpersonal relationships impacts facial mimicry.”

To verify her hypothesis, Associate Professor Fujimura started by using the “trust game,” a method often used in game theory and economic research. Here, a test participant pairs with a virtual “person” （here, “the Pair”） projected onto a computer screen. The participant plays the role of an “investor,” while the Pair is the “trustee.” Points are assigned to the investor, and any points “invested” （assigned） to the Pair （trustee） are multiplied by three （x3）. The Pair may then allot （“entrust”） the investor with some or none of the points assigned to the Pair as trustee （see Fig. 1）. Prior to playing the game, the participant is informed that points invested will be multiplied by three, and that the points finally held by the participant will be reflected in the remuneration that participant will receive for her/his participation. Here, two pattern types are prepared beforehand for the points returned to the investor by the Pair （as trustee）. When the Pair tends to assign （return） to the investor half of the points （multiplied by three） given to it, the Pair is a “trustworthy person.” Meanwhile, if the Pair tends to keep most of the points, then the Pair is an “untrustworthy person.” After the trust game is completed, a facial expression showing the “emotion” of the Pair is displayed to the participant, while any changes in the expression of the participant are measured using facial electromyography.

The results showed that while the participant mimicked the smile shown by the “trustworthy person” (the Pair), no such mimic response occurred when the “untrustworthy person” was displayed as smiling. It was also found that emotional (facial expression) mimicry in the case of anger or sadness (by the Pair) was not affected by the level of trustworthiness. “Although it was known that emotional mimicry was impacted by differences in the attributes and general impression of the other party, we were able to see changes in mimicry when we added the social factor of trustworthiness (Fig. 2). Mimicry of a smile conveys a message of affiliation to the other smiling person, while refusal to mimic the smile of an untrustworthy person might be a way of ‘adjusting’ the relationship to fit the circumstances.”

This prior research by Dr. Fujimura on the nature of communication as seen in emotional mimicry will be expanded in new studies. “Actually, there are two kinds of ‘trust.’ One is ‘trustworthiness,’ where one undergoes changes in trust level according to the actual behavior of others. The other is ‘general trust,’ which is a measure of how easy it is in general for an individual to come to trust others. As facial and other expressions serve as signals for building trust with another, then I hypothesize that people whom others find easy to trust are likely to be more sensitive and ‘attuned’ to the expressions of others; thus, facial mimicry might more readily occur in so-called ‘easy to trust’ people. Little data exists on the relationships between general trust and mimicry, so I definitely plan to investigate this.”

Dr. Fujimura is also engaged in the development of an expressions database that incorporates both categories and dimensions of emotions. Research on expressions in psychology and other fields requires a set of “standard” expressions for use as stimuli in tests. Already there exist for-pay facial expression databases, their costs have been prohibitive for ready use by researchers and students. Thus, Dr. Fujimura is constructing a database that will be open and free of charge to the general public.

In order to collect data for standardized expressions, Dr. Fujimura selected in tryouts four men and four women, ages 20s through 40s, who are skilled aspiring actors who can make easy-to-identify expressions. She then used a high-definition video camera to record a variety of their expressions. There are twelve expression types included in the database, including surprise, fear, sadness, anger, etc. Then, she collected data on the emotional states of each expression by using emotion classification in which participants were asked to choose the emotion label that best described the shown expression, and a single-item scale of pleasure and arousal. This database is widely used by researchers, as reflected in the growing number of references to this database cited by scholars in their published papers, etc. “We made this database as easy to use as possible in tests, by including all statistical information on ratings made for each specific emotion image. I have been contacted by persons who have used this database for presentation at scholarly conferences, etc., and some of these contacts have actually led to joint research. Certainly, this kind of research involves painstaking efforts, but it has certainly been worth it!”

A yearning to clarify the roles that human emotions play in building society

The inspiration for Associate Professor Fujimura to research emotions and expressions stems from her childhood. “Ever since I can remember, I have loved to watch people. I would ask myself, ‘Why is this person saying this?’ or ‘What is the meaning of this action or behavior?’ Today, we have physiological indices that help us to measure human emotions, including heartbeat, brain waves, etc. However, all of these are measurements made from outside the mind and body. The reason why I insist on studying expressions is that the expressions themselves have an impact even on the person who makes the expression, and that expressions serve as signals to others. In this way, emotions act as a hub or interface between oneself and the world. My desire is to clarify how expressions are used in the construction of human society. I do this by examining the relationships between emotions and expressions, and by determining how people ‘read’ the meanings communicated by expressions within these relationships.” Dr. Fujimura says this with a smile, and with her eyes sharply fixed on her ongoing research.

Determining the sources of diseases, and an optimal balance between active oxygen and antioxidant potential are key to maintaining good health

Like all living organisms, human beings undergo changes constantly throughout their lives. Once physical growth ceases and an individual transitions from the period of maturity, subsequent changes are a part of “aging.” No individual can avoid the phenomenon of aging, and active oxygen is thought to be deeply involved in this process. The overproduction of active oxygen due to an extreme lack of exercise, psychological burden, smoking, and other factors, destroys the balance between active oxygen within an organism and its antioxidant potential, that is, the ability of internal antioxidants to eliminate active oxygen. This state is known as antioxidative stress, and if this stress continues to be elevated, it can trigger diabetes and several other diseases.

Professor Hiroshi Ichikawa, who studies oxidative stress, states, “We used to think that active oxygen itself is a cause of physical damage and sought to eliminate active oxygen. However, we found that simply removing active oxygen led to the failure of the body to fight internal oxidation adequately (we call this the ‘antioxidant potential’). Thus, to maintain the balance between active oxygen and antioxidant potential, it is important to raise the levels of antioxidant potential.” Dr. Ichikawa evaluates antioxidant potential by assessing the body’s ability to remove six types of active oxygen. For this purpose, he utilizes a method known as “electron paramagnetic resonance (EPR) spin trapping.” Through this approach, Dr. Ichikawa found that depending on the disease and physical condition, the pattern of antioxidant potential differs for each active oxygen type. He believes that these differences can be used for disease diagnosis and prevention. 

Dr. Ichikawa also explained his concept of evaluating blood samples for changes in the antioxidant potential for the six types of active oxygen, resulting from the consumption of foods with potential health benefits (so-called “functional foods”). Based on such results, a physician can prescribe functional foods that are beneficial for each type of illness.

Dr. Ichikawa kickstarted his career as a clinical doctor. While working as a gastroenterologist, primarily in hospitals in the Kyoto Prefecture, he also conducted research on oxidative stress at a research laboratory. Since 2003, his key priority was preventative medicine, in particular, nutritional science. He also got involved in the education and training of managerial dieticians. “In my clinical work during the influenza epidemic of the 1998/99 season, I felt strongly about the importance of daily diet. I recognized the differences in symptoms between those who ate properly and those who did not. Ever since then, I have studied the relationships between oxidative stress and diet, with a focus on functional foods. Clinical medicine is certainly fascinating, as it gives you the chance to meet individually with each patient. Yet, the number of lives one can positively save is limited. I would like to save as many lives as possible, through the fruition of my research work,” he explains.

Confirming that ultrasonic radiation improves antioxidant potential to the same extent as physical exercise

Surprisingly, it is not widely known that active oxygen produced by muscles is involved in the health-maintenance effects of exercise. A minute amount of active oxygen is generated whenever an organism is physically stimulated, even slightly. This triggers an adaptive reaction designed to overcome that stimulus. The special focus of Dr. Ichikawa’s research in recent years involves the use of this reaction, specifically “the improvement of antioxidant potential by means of ultrasound radiation.” He hypothesized that equivalent effects as those from physical exercise can be obtained when stimulation occurs via ultrasound radiation in lieu of exercise. Dr. Ichikawa has been conducting experiments on rats to study optimal ultrasound intensities for irradiation of an organism (Figure. 1). Based on blood tests performed on day eight of the experiment, he found that antioxidant potential improved when a rat was irradiated with a safe dose of ultrasound, once every two days. This result demonstrates that ultrasound radiation performed at low intensities might generate the same effects as that of exercise.

Next, using nematodes—standard model organisms used for aging research—Dr. Ichikawa tested the effects of ultrasound irradiation on longevity. When low intensity ultrasound irradiation was conducted for one minute, three times a week, experimental results revealed an extension of the nematode lifespan. Dr. Ichikawa used a further approach to verify the effects of ultrasound irradiation on strengthening antioxidant potential. Here, tumor necrosis factor-α (TNF-α), a cytokine that promotes muscle atrophy, is added to a culture medium, in which the skeletal muscle cells of a mouse undergo ultrasound irradiation. He then found that muscle atrophy due to TNF-α was suppressed by the ultrasound irradiation. He adds, “Ultrasound irradiation may help to prevent sarcopenia, an oxidative stress-related disease that causes reduced muscle mass and decreased muscle strength. We think that this finding may contribute to an extension of healthy life expectancy, especially important in Japan with its aging population.”

Dr. Ichikawa aims to develop this health-management method by means of ultrasound irradiation for human applications. He notes, “This method is not limited to sarcopenia and aging. It includes all oxidative stress-related diseases, including diabetes, dementia, and more. Since this method uses irradiation at low intensities, within established safety standards, its safety is assured. This is a positive aspect when considering its potential applications.” 

Since ultrasound irradiation devices are already used for a variety of applications, Dr. Ichikawa says that once optimal irradiation conditions are determined for humans, the development of dedicated devices can quickly get underway. A wide range of users are anticipated, from aged persons to athletes, to the hospitalized and patients living at home. These devices will be extremely useful and practical, in that they could be used at hospitals, training facilities, and in private homes. Dr. Ichikawa says, “Our next step is to collect fundamental data on humans, to determine optimal irradiation conditions. We also plan to earnestly perform research toward practical uses, including ascertaining the effects of irradiation at different body sites. We are collaborating with companies, including for the development of irradiation devices that can be used at home. We plan to move forward closely together with our collaborators” (Figure. 2).

Elucidating tolerance induction mechanisms for oxidative stress aimed toward order-made diagnostics and treatments

Dr. Ichikawa will refer to Japanese standards for food safety for his further research on improving sperm function. He mentions, “Among all cells in the body, sperm cells have the most sensitive reactions to oxidative stress. Currently, no objective data exists regarding the benefits of antioxidant materials in infertility treatment, so we are still working to gather related findings.” Male impotence is triggered by a decline in sperm function, as seen in oligospermia (low sperm count) and asthenospermia (a condition where sperm have difficulty moving or swimming properly). Based on the results from animal experiments, Dr. Ichikawa has determined that an antioxidant known as S-allyl cysteine (SAC) improves sperm function. SAC is a functional component present in garlic and since it has been confirmed to be as safe as essential amino acids, long-term consumption is possible. He is now exploring collaborations with private companies for the development of related medicines and functional foods.

　Dr. Ichikawa serves as the Director of the Doshisha University Research Center for Cell Protection and Regeneration Systems. This post enables him to enjoy exchanges with scholars and researchers from a wide variety of disciplines. His Center collaborates with researchers outside of Doshisha University and performs joint research with private companies to determine clinical applications for its research findings.

In the future, Dr. Ichikawa hoped to provide order-made diagnostics personalized to each patient’s antioxidant potential, which is measured during an examination, much like how blood pressure is measured for medical examinations and treatments. With this as his aim, he is concentrating on elucidating the mechanisms that induce tolerance for antioxidative stress within an organism, by accumulating more data.

Once this is achieved, he has plans for clinical trials for patients in rehabilitation for sarcopenia, stroke, and more, to benefit from the practical use of ultrasound irradiation. “Making marketable products is not our only aim. Basic knowledge surrounding ultrasound technology needs to be provided to hospitalized patients and people at clinical sites. Since the procedure will be ready at hand, it will make it error prone. We are actively striving to overcome, one by one, the hurdles toward real applications,” he concludes. Thus, Dr. Ichikawa will continue to confront his field’s challenges as he seeks to make major contributions in broad fields, for the maintenance of human health.

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