What is kanjo （感情）? Which of the following folk/scientific concepts is the same as the Japanese word kanjo: affect, emotion, or feeling? Despite discussions, Japanese psychologists have still have not reached consensus on these fundamental questions about the definition of the phenomenon. This research discusses four difficulties/challenges around the definition of kanjo: (a) polythetic qualities of kanjo, (b) comparability of kanjo between everyday life and science, (c) translation equivalence between kanjo and its related terms, and (d) English dependency of the conceptual definition in psychology. We are skeptical about the exclusive definitive translation of kanjo-related terms (e.g., affect/kanjo, emotion/jodo （情動）, feeling/kanjo); thus, we have coined the following three novel terms: A-kanjo, E-kanjo, and F-kanjo (corresponding generally to affect, emotion, and feeling, respectively). Further, to consider the definition of kanjo, we reviewed the similarities and differences between a few promising approaches in the working and scientific definitions of emotion, theory development, theory convergence, and unifying framework of emotion research. Finally, we suggest a future direction for defining kanjo and research on kanjo in Japan.

Until now, physiological psychology has contributed to the development of emotion research with the help of various biological measurement techniques. Certain methods, such as cardiovascular measurement, electrodermal activity, endocrine activity, electroencephalography (EEG), and neuroimaging, have been used to visualize biological reactions associated with emotions and to reveal the importance of physical reactions and their neural basis in emotional experience. Furthermore, psychophysiological indicators can reflect various mental processes. This study reviews the richness of knowledge obtained from psychophysiological methods by introducing concepts derived from psychophysiological indices, such as arousal, stimulus–response (S–R) specificity, the cardiac–somatic concept and internal receptive sensation, and emotion research using these indices. Finally, the study discusses the contribution of psychophysiology to the research on emotion and presents a few cautionary notes on the understanding and interpretation of psychophysiological data in emotion research.

Focusing on interpersonal gratitude, four methods of inducing emotions in participants are reviewed: autobiographical memories, scenarios (or vignettes), laboratory experiments, and real-world phenomena. Autobiographical memories enable researchers to easily actualize high statistical power and examine causal effects through a random assignment. Scenarios not only allow for random assignments and attainment of high statistical power like autobiographical memories, but also enable strict control of several residual variables. Laboratory experiments can present participants with real stimuli to induce emotion with strong control of residual variables. Real phenomena can present participants with real-world stimuli and prevent deception, which is a known cause of subject pool contamination. Since tradeoffs exist between methods, using only one method would hinder a deep understanding of emotions. Hence, researchers must give as much attention to updating their knowledge about methodologies as the study of emotions itself.

This work addresses the difficulty in identifying and measuring emotions related to moral judgment. Two issues (emotion correspondence and translation issues) are discussed in terms of self-report methodology using scenarios and scales written in language. Self-report methodology has often been used in moral psychology. Based on the assumption regarding one-on-one correspondence of a moral domain and specific emotion, this methodology labels emotions with language. However, the mixed findings from the previous research suggest that the emotion correspondence issue should be discussed with caution. Additionally, labeling (i.e., translating) not only needs to select appropriate words, but also consider the culture. Other methodological perspectives are for example the physiological indices. Researchers rarely consider the extent of the scope of their own methodology, and what others having different perspectives can do with their methodology. They must listen to other sides, draw realistic pictures of each other’s theories and methodologies, and plan practical collaboration. In future, such efforts will contribute to a deeper understanding of the emotions involved in moral judgment.

This article reviews existing literatures that measure emotional experiences via the experience sampling method (ESM), and discusses prospects of using ESM for emotion studies. This review suggests that ESM can reveal multiple aspects of emotional experiences: namely, momentary affect/emotions, emotion variability, emotion differentiation, and emotion network density. Hence, the ESM provides a powerful approach to advance emotion studies; however, there are also points to keep in mind. Lastly, this article addresses points of caution for using ESM to study emotions, and discusses prospects of this methodology.

The present review introduced the current progress in understanding the relationship between emotion and physiological research, particularly through studies of the autonomic nervous system (ANS) and functional magnetic resonance imaging (fMRI). A review of the existing literature indicates that while ANS research has demonstrated an association between physiological responses and emotional arousal, it has not yet fully explored the physiological associations with basic emotions including happiness, sadness, and anger. In contrast, fMRI studies have shown that neural activity in the distributed whole brain is related to basic emotions, rather than the circumplex model of emotion, which consists of valence and arousal dimensions. Additionally, fMRI research has also revealed that various emotional categories correspond with distinct patterns of neural activity. To gain a more comprehensive understanding of the connection between emotions and physiological systems, it is crucial that future research adopts a multidisciplinary approach that incorporates various indicators and methodologies.

This paper aims to consider whether emotions can be measured using an electroencephalogram (EEG). Although there are some EEG indices related to emotions, none of them reflect emotional processing directly. In addition, some limitations in EEG analyses make it challenging to capture characteristics of emotions, and it is necessary to strictly control measurement conditions to correctly interpret EEG indices. Although assessing emotions through EEG is not easy, it captures and reflects cognitive processing (e.g., perception and attention) in the cerebral cortex. Researchers can indirectly observe changes in an emotional state by examining EEG indices of cognitive processing that co-vary with the emotion. Thus, it is a valid way to measure emotions. These points are discussed in reference to an EEG study on humor processing conducted by the author’s group (Sanada et al., 2022)²。

Awe is an emotional response that has long been examined in the humanities and sociology as a sublime phenomenon, and has recently attracted attention in psychology. While previous studies investigated the emotion of awe with different methodologies and approaches, the current empirical literature still lacks an integrated perspective. This paper reviews and compares studies on awe using subjective, behavioral and physiological/neural measures, and subsequently proposes an overarching framework to understand awe through the lens of functions of awe. I further discussed how we could establish an interdisciplinary basis for understanding awe and integrate diverse methodological approaches.

This research was conducted as part of a pre-conference held at the joint conference of the Japanese Society of Physiological Psychology and Psychophysiology and the Japan Society for Research on Emotions in 2022 entitled “Do we measure what we want to measure? Toward the measurement of subjective and physiological indices of emotion over the next decade.”

The main purpose of this study was to clarify the beliefs about the definitions of emotion and physiological response and the validity of measurement indices. Participants were asked several questions to assess their beliefs about the definitions and the validity of measurements before and after attending the pre-conference. The results suggest that the beliefs about the validity of subjective index were relatively higher than those of physiological indices such as event-related potential (ERP), functional magnetic resonance imaging (fMRI), and autonomic nervous system indices. Differences between affiliated academic societies were also discussed.

Emotion is a multifaceted phenomenon, and its definition has long been controversial. The question of whether we measure what we want often arises in research practices. This paper discusses the complementary relationships between physiological and self-report measures in studying emotional phenomena and interpretative issues linking these measures to underlying psychological constructs. I begin by reviewing psychophysiological relationships based on the psychophysiological inference framework. I then discuss how findings based on self-reported measures and psychophysiological research can mutually support each other. However, collected data are often open to interpretation, such as naming a dimension where multiple labels are possible. Thus, questions such as what was measured and how we can interpret them arise. Such questions lead to further debate on the psychological constructs we want to measure, including emotions.