Hideyoshi Yanagisawa

The University of Tokyo | Todai · Department of Mechanical Engineering

Abstract: Prior expectation affects posterior perceptual experience. This contextual bias is called expectation effect. Previous studies have observed two different patterns of expectation effect: contrast and assimilation. Contrast magnifies the perceived incongruity, and assimilation diminishes the incongruity. This study proposes a computational mode...

Acceptance of novelty depends on the receiver's emotional state. This paper proposes a novel mathematical model for predicting emotions elicited by the novelty of an event under different conditions. It models two emotion dimensions, arousal and valence, and considers different uncertainty levels. A state transition from before experiencing an even...

Appropriate levels of arousal potential induce hedonic responses (i.e., emotional valence). However, the relationship between arousal potential and its factors (e.g., novelty, complexity, and uncertainty) have not been formalized. This paper proposes a mathematical model that explains emotional arousal using minimized free energy to represent infor...

An appropriate level of arousal induces positive emotions, and a high arousal potential may provoke negative emotions. To explain the effect of arousal on emotional valence, we propose a novel mathematical framework of arousal potential variations in the dual process of human cognition: automatic and controlled. A suitable mathematical formulation...

Increasing the aesthetic quality of a shape is an important objective for enhancing the attractiveness of a product. Many studies on shape generation systems are based on the user’s emotion as a means of supporting the ideas of product designers. However, most of the proposed systems are unsuitable for extrapolation of shapes because they rely on t...

Emotions consist of two dominant dimensions: arousal (intensity) and valence (positivity and negativity). Psychological theories such as arousal potential suggest that an appropriate level of arousal would induce a positive valence, but extreme arousal potentials induce negative valence. This chapter proposes a general mathematical formulation of t...

Olfaction is an area of great interest as a new interface for digital experience. To provide rich multimodal experiences with limited amount of scent, we propose efficient olfactory ejection methods: pulse ejection and habituation ejection. These methods are based on Bayesian cross-modal model of olfaction. The pulse ejection gives off odour at reg...

An appropriate level of arousal induces positive emotions, and a high arousal potential may provoke negative emotions. To explain the effect of arousal on emotional valence, we propose a novel mathematical framework of arousal potential variations in the dual process of human cognition: automatic and controlled process. Although models have been pr...

The brain always predicts the world. We see brain's predictions as the world. Sensory observations are the only source of correction for predictions. Our perception is an estimate based on predictions and sensory observations. This estimation follows Bayes' theorem. Prediction error is calculated as information surprise. The brain recognizes the wo...

Humans pursue well-being in their lives. Well-being encompasses positive emotions, life satisfaction, well-functioning, meaning of life, and self-growth. In ancient times, sharing is an intimate behavior which solidates strong community and leads to an ideal life which refers to well-being in the present. Sharing economy sheds light on a novel busi...

In a human centred society, sense of safety perceived by people is important to consider as well as actual safety. The gap between expectations and reality in safety causes social problems. Overestimation of safety provokes dangerous behaviours, while underestimation of safety causes excessive behavioural restraint. For example, in COVID 19 pandemi...

Interest is a positive emotion evoked by recognition from a new perspective. It motivates learning and creative activities. Aha moments, a timing of sudden realization, are often experienced in such recognition process. In this paper we propose a mathematical that explains emotions such as interest in aha moment. Graf's pleasure-interest model of a...

State of charge (SOC) management is necessary for electric vehicle (EV) driving safety and comfort. However, the SOC estimated by a human driver may differ from the actual SOC, inducing negative emotions and false charging behaviors. Currently , a model for explaining or estimating driver perceptions and emotions regarding SOC is lacking. Therefore...

DX stands for digital experience meaning a digitally structured experience. Recently, the use of DX has become particularly widespread. In order to improve the richness of DX, we consider visual-olfactory integration in perception by adding olfactory stimuli to DX. We formulate a Bayesian perceptual model to explain the DX richness. The model predi...

Appropriate levels of arousal potential evoke hedonic responses. Yanagisawa, the second author, previously proposed a mathematical model of emotional arousal caused by novelty, uncertainty, and complexity using information-theoretic free energy. In this study, we formulate the information processing flow in the brain based on the dynamics of free e...

DX stands for digital experience meaning a digitally structured experience. Recently, the use of DX has become particularly widespread. In order to improve the richness of DX, we consider visual-olfactory integration in perception by adding olfactory stimuli to DX. We formulate a Bayesian perceptual model to explain the DX richness. The model predi...

Appropriate levels of arousal potential evoke hedonic responses. Yanagisawa, the second author, previously proposed a mathematical model of emotional arousal caused by novelty, uncertainty, and complexity using information-theoretic free energy. In this study, we formulate the information processing flow in the brain based on the dynamics of free e...

Emotion modeling has been a significant task in engineering design to optimize the users' feedback. Psychology studies have established explanatory relation of agent's outcome emotion with fluency from perceived stimuli. Friston proposed the free-energy principle modeling the human perception process in a Bayesian form to apply the emotion models i...

柳澤秀吉, 自由エネルギーを用いた認識・行動・感情の数理モデル（感性設計のための数理 第3報）, 設計工学, Vol.75, No.2, pp.41-48, 2022.

Design aesthetics is one of the most important factors in the attractiveness of industrial products. In this study, we focused on the theory of aesthetics, which states that moderate novelty and complexity maximize pleasant feelings, and formulated the novelty and complexity perceived from a closed curve contour shape using curvature and Fourier ex...

Sense of agency is the sense that I am the one who is causing or generating an action, and, through them, controlling events in the outside world. We previously proposed a mathematical model that predicts sense of agency in order to design the machine that gives users appropriate sense of agency. The objective of this research is to apply the mathe...

Olfaction is an area of great interest as a new interface for digital experience. To provide rich multimodal experiences with limited amount of scent, we propose efficient olfactory ejection methods: pulse ejection and habituation ejection. These methods are based on Bayesian cross-modal model of olfaction. The pulse ejection gives off odour at reg...

Novel and semantically associated words facilitate broadening ideas. In this study, we propose a computational system that recommends novel and semantically associated words. The algorithm of the system is based on free energy principle explaining cognition of organisms in a general manner. The system recommends words while controlling a balance be...

Sense of agency (SoA) is the subjective sense of controlling one’s own actions. SoA is important in the context of the interface design because users get SoA when they receive the machine response. We considered SoA is designed properly by mathematically modeling. The brain is the information processing machine. We propose the model using free ener...

In recent years, autonomous mobile robots have been operated for transportation, cleaning, guidance, etc., and the opportunities for humans to interact with these robots are increasing. In an environment where humans and robots share a space, safe and worry-free behavior are required for robots. It is expected that the improvement of technology wil...

When driving an electric vehicle, we predict and recognize a state of charge. However, the quantity is almost impossible to observe precisely and it is considered that there is an effect of some parameters such as an intensity of prediction, an accuracy of observation and a noise on system. We derived a time series mathematical model of human perce...

This study aims to find how space discrepancy and latency affect the implicit and explicit sense of agency (SoA) with discrete and continuous operations, and whether these two factors have an interaction effect. In Experiment 1, for discrete operations, participants were asked to press a button to make a ball move. In Experiment 2, for continuous o...

Autonomous mobile robots play an important role in society in recent years. Living with robots become more common, and there is an increasing demand for robots such as in delivery service. For smooth interaction and mutual respect between humans and robots, human predictability for robot motions has to be improved, as if humans can easily predict a...

Managing the state of charge (SOC) is necessary for safe and comfortable driving of an electric vehicle (EV). However, the battery consumption speed varies due to factors such as outside temperature, frequency of acceleration and deceleration, and the current state of remained electricity. These factors cause a deviation of the recognition of SOC e...

An individual’s acceptance of novelty depends on their emotions. We previously developed mathematical models of emotional dimensions associated with novelty, such as arousal (i.e., surprise) and valence (i.e., positivity and negativity). The models based on Bayesian theorem have three parameters: prediction error, uncertainty and external noise. Ba...

Presented at Symposium of Safety Engineering 2021

Special issue on value co-creation at Journal of Kansei Engineering.

One becomes accustomed to repeated exposures, even for a novel event. In the present study, we investigated how predictability affects habituation to novelty by applying a mathematical model of arousal that we previously developed, and through the use of psychophysiological experiments to test the model’s prediction. We formalized habituation to no...

With the growing utility of today's conversational virtual assistants, the importance of user motivation in human-artificial intelligence interactions is becoming more obvious. However, previous studies in this and related fields, such as human-computer interaction, scarcely discussed intrinsic motivation (the motivation to interact with the assist...

When driving an electric vehicle, we predict and recognize a state of charge. However, the quantity is almost impossible to observe precisely and it is considered that there is an effect of some parameters such as an intensity of prediction, an accuracy of observation and a noise on system. We derived a time series mathematical model of human perce...

In recent years, autonomous mobile robots have been operated for transportation, cleaning, guidance, etc., and the opportunities for humans to interact with these robots are increasing. In an environment where humans and robots share a space, safe and worry-free behavior are required for robots. It is expected that the improvement of technology wil...

A user operating a mechanical devise receives sensory information (e.g., sounds and vibrations) generated by the mechanical operation in response to the operation input. With the digitization of products, the mechanical operation response is removed as is the associated sensory information, thus there is no confirmation of the completed operation....

To realize a human-centered society such as Society 5.0 formulated by Japanese government, it is important to understanding and modeling human perceptions and emotions. The author has proposed affective (or Kansei in Japanese) design engineering [1, 2] that bridge the gap between engineering physical world and user's psychological world. Affective...

The Sense of Agency (SoA) is the subjective awareness of controlling external world through one’s action. This paper proposes a mathematical model to explain the degree of SoA using information gain, representing the difference between expected and actual sensory responses to an operational action. We hypothesize that the degree of SoA is proportio...

Sense of agency is the sense that an event is caused by oneself. In the context of man-machine interfaces, it has been proposed that the prediction error of a sensory outcome decreases the sense of agency. We assume that the information content of the sensory response represents the prediction error and thus explains the extent of sense of agency....

The function and performance of cloud connected products such as AI speakers are continuously updated over time. Such updates are based on the user’s exploration of unknown functions. Apter’s reversal theory proposed a mental condition termed the paratelic mode in which one acts to explore the purpose and enjoy certain actions in itself. We assume...

In recent years, electric vehicles have become increasingly popular. To operate safely them requires the recognition of the appropriate state of charge (SOC). However, the different between the real SOC and the predicted SOC can lead to problems such as missing the timing of charging. In order to solve this problem, we modeled the relationship betw...

Autonomous mobile robots are essential for us in recent years. Living with robots become more common, and we humans and robots are required to respect each other. For smooth interaction between humans and robots, human predictability for robot motions desired to be improved as if human can easily predict another human’s motions. We model human pred...

It is said that the relationship between “novelty” and “aesthetic liking” is expressed as an inverted U-shape. The latest studies about perception emphasize “novelty” as a factor of emotion and quantify “novelty” by assessing the difference in amount of information using Kullback-Leibler (KL) divergence. The previous research quantified “novelty” o...

With the growing utility of today's conversational virtual assistants, the importance of user motivation in human-AI interaction is becoming more obvious. However, previous studies in this and related fields, such as human-computer interaction and human-robot interaction, scarcely discussed intrinsic motivation and its affecting factors. Those stud...

I introduce our mathematical model of emotions evoked by novel events. The core idea is to use information contents processed in the brain through experiencing an event to represent novelty and its emotions. The model explains human surprise of novelty as Kullback-Leibler divergence of Bayesian posterior and prior, i.e. information gain. We formali...

Information-theoretic free-energy means the difference between recognition model and generative model. The principle of free-energy minimization suggests that the recognition model must follow a Bayesian posterior. I consider that the minimized free-energy represents potential information contents to be processed in the brain after recognizing exte...

This study extends the mathematical model of emotion dimensions that we previously proposed (Yanagisawa, Kawamata, & Ueda, 2019) to consider perceived complexity as well as novelty, as a source of arousal potential. Berlyne's hedonic function of arousal potential (or the inverse U-shaped curve, the so-called Wundt curve) is assumed. We modeled the...

Previous mathematical models developed to optimize the degree of novelty in product design have represented novelty by emotional dimensions such as arousal (surprise) and valence (positivity and negativity). Formalizing arousal as Bayesian information gain and valence as a function of arousal based on Berlyne's arousal potential theory, the model i...

One becomes accustomed to repeated exposures, even for a novel event. In the present study, we investigated how predictability affects habituation to novelty by applying a mathematical model of arousal that we previously developed, and conducted a psychophysiological experiment to test the model prediction. We formalized habituation to novelty as a...

Studies on autonomous driving systems are being conducted to realize a safe and secure mobile society. According to these studies, the safety of the system and the driver’s feeling of safety often do not match. To enable automatic driving control according to the driver's comfort, previous researchers introduced a risk feeling index to quantify the...

Studies of autonomous driving systems are being conducted to realize a safe and secure mobile society. According to these studies, the safety of the system and the driver’s feeling of security often do not match. To enable automatic driving control according to the driver's comfort, previous researchers introduced risk feeling index to quantify the...

Novelty is an essential factor in design that is deemed attractive and creative by humans. However, an individual’s acceptance of novelty depends on their emotions. Knowledge about the range of novelty which ones accept will help to create attractive design targeting certain users. We previously developed a mathematical model of emotional dimension...

柳澤秀吉, 感情の数理（感性設計のための数理モデリング第２報）, 設計工学, Vol.55, No. 4., 2020, pp.203-209. Yanagisawa, H. (2020). A Mathematical Principle of Emotions(Mathematical Modeling for Kansei Design, 2nd report), Journal of Japan Society for Design Engineering, Vol.55, No. 4. pp.203-209.

[This corrects the article DOI: 10.3389/fncom.2019.00002.].

This study extends the mathematical model of emotion dimensions that we previously proposed (Yanagisawa, et al. 2019, Front Comput Neurosci) to consider perceived complexity as well as novelty, as a source of arousal potential. Berlyne's hedonic function of arousal potential (or the inverse U-shaped curve, the so-called Wundt curve) is assumed. We...

This chapter discusses a mathematical model of emotions associated with novelty at variable uncertainty levels. The model predicts dominant emotion dimensions, arousal (intensity of emotion), and valence (positivity or negativity). To represent the arousal level, we used Kullback–Leibler divergence of Bayesian posterior from the prior, which we ter...

I introduce our mathematical model of emotions evoked by novel events. The core idea is to use information contents processed in the brain through experiencing an event to represent novelty and its emotions. The model explains human surprise of novelty as Kullback–Leibler divergence of Bayesian posterior and prior, i.e. information gain. We formali...

Information-theoretic free-energy means the difference between recognition model and generative model. The principle of free-energy minimization suggests that the recognition model must follow a Bayesian posterior. I consider that the minimized free-energy represents potential information contents to be processed in the brain after recognizing exte...

Sense of Agency (SoA) is the sense that an event is caused by oneself. In a context of man-machine interface, it has been proposed that the prediction error of operational response decreases SoA. We assume that the information contents of the operational response represents the prediction error and thus explains the extent of SoA. We use the negati...

For products that are connected to the cloud, such as AI speakers, and whose functions and performance are expanding over time, their true value are found by exploring unknown functions instead of using only the functions that users are familiar with. Apter' s reversal theory proposed that there are two mental conditions of motivation, telic mode a...

Recognition of a category inferred by a stimulus affects its perception. The effect of category recognition is important to understand customers’ perceptions of an artifacts in product design. In this study, we propose a hierarchical Bayes model of the category recognition process. We formulate the probability of a category recognition as a functio...

Invited lecture at Sony Technology Exchange Fair 2019.

Novelty is an important factor of creativity in product design. Acceptance of novelty, however, depends on one’s emotions. Yanagisawa, the last author, and his colleagues previously developed a mathematical model of emotional dimensions associated with novelty such as arousal (surprise) and valence (positivity and negativity). The model formalized...

Verbalizing kansei qualities (e.g. sensory properties and emotions) is required in a kansei design process involving ideation, evaluation, and analysis. This study aims to develop a systematic method and a support system to acquire words effectively expressing certain kansei qualities. This paper proposes a method for acquiring effective words base...

The sense of agency (SoA) is a central factor while judging if an experience is under the agent of one's own actions. SoA can be applied to product designing, a big part of which is operational response designing. We hypothesized that Bayesian information gain explains the extent of Sense of Agency. In this paper, we formulated the Sense of Agency...

Several assistive technologies for users’ operations have been recently developed. A user’s sense of agency (SoA) decreases with increasing system assistance, possibly resulting in a decrease in the user’s sense of fulfillment. This study aims to provide a design guideline for an assistive method to maintain and improve the sense of fulfillment wit...

Throughout the course of product experience, a user employs multiple senses, including vision, hearing, and touch. Previous cross-modal studies have shown that multiple senses interact with each other and change perceptions. In this paper, we propose a methodology for designing multisensory product experiences by applying cross-modal effect to simu...

Hideyoshi Yanagisawa, (2019). Towards Principia of Kansei (A theory of relativity in perception), Journal of the Japan Society of Mechanical Engineers,Vol.122, No.1208, pp.12-15. (in Japanese) 柳澤秀吉，(2019). 感性のプリンキピアを目指して ～知覚の相対論とその数理，日本機械学会誌，Vol.122, No.1208, pp.12-15.

This study aimed to develop a method to evaluate the sense of discrepancy to the operation response quantitatively. We examined the availability of event-related potential (P300), which is considered to reflect attention to stimulation, to evaluate the sense of discrepancy to the product response to the user's action. In the experiment using subjec...

Novelty is an important factor of creativity in product design. Acceptance of novelty, however, depends on one's emotions. Yanagisawa, the last author, and his colleagues previously developed a mathematical model of emotional dimensions associated with novelty such as arousal (surprise) and valence. The model formalized arousal as Bayesian informat...

This study aimed to develop a method to evaluate the sense of discrepancy to the operation response quantitatively. We examined the availability of event-related potential (P300), which is considered to reflect attention to stimulation, to evaluate the sense of discrepancy to the product response to the user's action. In the experiment using subjec...

Several assistive technologies for users' operations have been recently developed. A user's sense of agency (SoA) decreases with increasing system assistance, possibly resulting in a decrease in the user's sense of fulfillment. This study aims to provide a design guideline for an assistive method to maintain and improve the sense of fulfillment wit...

Erratum ISASE2019 Session ID: KeyNoteTalk-1 Reference [10] Incorrect: H. B. Barlow, "Possible principles underlying the transformation of sensory messages," Sensory communication, pp. 217-234, 1961. Correct: X.-X. Wei and A. A. Stocker, "A Bayesian observer model constrained by efficient coding can explain 'anti-Bayesian' percepts," Nature Neurosc...

According to the self-determination theory, we considered the disappearance of autonomy of product operation result in the decrease in sense of fulfillment of product use. The purpose of this study was to develop a mathematical model that explained the effect of sense of agency (SoA) on sense of fulfillment. For this purpose, we integrated the idea...

The sense of agency (SoA) is an important Kansei quality in interactive design. It refers to the feeling that one is in control of his/her actions and, through them, of events in the outside world. Our living world consists of two dimensions: space and time. One perceives and operates objects in time and space. Thus, time and space are essential fa...

Conversational virtual assistants have exploded in popularity in recent years. Developers have been working to create personality in virtual assistants, so that users treat them more than mere automation tools. Among other factors, motivation is considered playing an important role. However, previous researches focused mainly on extrinsic motivatio...

Novelty is an important factor of creativity in product design. Acceptance of novelty, however, depends on one’s emotions. Raymond Loewy, a pioneer of industrial design, defined a broader term between attraction of novelty and fear of the unknown MAYA (Most advanced, yet acceptable), which is important for new designs that are widely accepted in so...

According to the self-determination theory, we considered the disappearance of autonomy of product operation result in the decrease in sense of fulfillment of product use. The purpose of this study was to develop a mathematical model that explained the effect of sense of agency (SoA) on sense of fulfillment. For this purpose, we integrated the idea...

Novelty is an important factor of creativity in product design. Acceptance of novelty, however, depends on one's emotions. Raymond Loewy, a pioneer of industrial designers, defined a broader between attraction of novelty and fear of the unknown MAYA (Most advanced, yet acceptable), which is important for a new design that is widely accepted in soci...

The sense of agency (SoA) is an important Kansei quality in interactive design. It refers to the feeling that one is in control of his/her actions and, through them, of events in the outside world. Our living world consists of two dimensions: space and time. One perceives and operates objects in time and space. Thus, time and space are essential fa...

Prior expectation affects posterior experience and emotions. This psychological effect is called expectation effect. Two different patterns of expectation effect, contrast and assimilation, were observed. In this talk, I proposed a mathematical model of the expectation effect that explains the conditions of contrast and assimilation[1]. I hypothesi...

Conversational virtual assistants have exploded in popularity in recent years. Developers have been working to create personality in virtual assistants, so that users treat them more than mere automation tools. Among other factors, motivation is considered playing an important role. However, previous researches focused mainly on extrinsic motivatio...