Masahiko Inami

Keio University · Graduate School of Media and Governance

Motor contagions refer to implicit effects induced by the observation of actions made by others on one’s own actions. A plethora of studies conducted over the last two decades have demonstrated that both observed and predicted actions can induce various kinds of motor contagions in a human observer. However, motor contagions have always been invest...

https://dl.acm.org/doi/pdf/10.1145/3613904.3642340

Visuomotor synchrony in time and space induces a sense of embodiment towards virtual bodies experienced in first-person view using Virtual Reality (VR). Here, we investigated whether temporal visuomotor synchrony affects avatar embodiment even when the movements of the virtual arms are spatially altered from those of the user in a non-human-like ma...

The reflection light forms the core of our visual perception of the world. We can obtain vast information by examining reflection light from biological surfaces, including pigment composition and distribution, tissue structure, and surface microstructure. However, because of the limitations in our visual system, the complete information in reflecti...

Motor contagions refer to implicit effects in one's actions induced by the observation of actions made by others. A plethora of studies over the last two decades have exhibited that observed, as well as predicted, actions can induce various kinds of motor contagions in a human observer. However, motor contagion has always been investigated in regar...

We propose SolefulTap for a novel tap dancing experience. It allows users to feel as if they are tap dancing or appreciate a tap dancing performance using the sensations of their own feet. SolefulTap uses a method called Step Augmentation that provides audio-haptic feedback to users, generating impacts in response to users' simple step motions. Our...

When humans generate stimuli voluntarily, they perceive the stimuli more weakly than those produced by others, which is called sensory attenuation (SA). SA has been investigated in various body parts, but it is unclear whether an extended body induces SA. This study investigated the SA of audio stimuli generated by an extended body. SA was assessed...

In this study，we focus on developing a sit-to-stand movement classification method using pressure sensors that are environment-installed．Sit-to-stand is a basic movement that is important for daily life， but can become difficult with age or certain health conditions．The movement has three phases that are difficult to distinguish visually，so the goa...

The ability to localize an object moving in three dimensions without the need for sight can lead to improve spatial awareness and invoke novel experiences. While haptic shear stimulus has been shown to be capable of presenting both mobile and static two dimensional stimuli which can be localized, the presentation of depth using this approach has no...

Recently, wearable robots, which add extra limbs like arms or legs, have been researched for the purpose of human augmentation. However, these wearable approaches, due to their weight and configuration of themselves, affect the inertia of the users and interfere with users walking. In this research, we propose a novel form of a mobile robot that is...

The supernumerary robotic limb system expands the motor function of human users by adding extra artificially designed limbs. It is important for us to embody the system as if it is a part of one’s own body and to maintain cognitive transparency in which the cognitive load is suppressed. Embodiment studies have been conducted with an expansion of bo...

Human behavior and perception are optimized for a single body. Yet, the human brain has plasticity, which allows us to extend our body schema. By utilizing technology like robotics or virtual reality (VR), we can modify our body parts or even add a new body to our own while retaining control over these parts. However, the update of body cognition w...

The authors report a demonstration in which a motion-defined boundary enhances the effects of a lower region cue in depth perception. Although the lower region cue has been proposed as a potential depth cue, its effect is weak in the static image. Their demonstration reveals that the lower region is almost unambiguously perceived as being in front...

We propose a concept called “JIZAI Body” that allows each person to live the way they wish to live in society. One who acquires a JIZAI Body can (simultaneously) control (or delegate control) of their natural body and extensions of it, both in physical and cyberspace. We begin by describing the JIZAI Body and the associated JIZAI state in more deta...

The supernumerary robotic limb system expands the motor function of human users by adding extra artificially designed limbs. It is important for us to embody the system as if it is a part of one’s own body and to maintain cognitive transparency in which the cognitive load is suppressed. Embodiment studies have been conducted with an expansion of bo...

The supernumerary robotic limb system expands the motor function of human users by adding extra artificially designed limbs. It is important for us to embody the system as if it is a part of one’s own body and to maintain cognitive transparency in which the cognitive load is suppressed. Embodiment studies have been conducted with an expansion of bo...

Recognizing foot gestures can be useful for subtle inputs to appliances and machines in everyday life, but for a system to be useful, it must allow users to assume various postures and work in different spaces. Camera-based and pressure-based systems have limitations in these areas. In this paper, we introduce AnkleSens , a novel ankle-worn foot...

Visual perspective taking is inferring how the world looks to another person. To clarify this process, we investigated whether employing a humanoid avatar as the viewpoint would facilitate an imagined perspective shift in a virtual environment, and which factor of the avatar is effective for the facilitation effect. We used a task that involved rep...

Recent advances in human-computer integration (HInt) have focused on the development of human-machine systems, where both human and machine autonomously act upon each other. However, a key challenge in designing such systems is augmenting the user’s physical abilities while maintaining their sense of self-attribution. This challenge is particularly...

Somatosensory game-based rehabilitation has recently experienced rapid increases in demand and scale in the health promotion market. However, the existing research on this topic mostly focuses on treatment efficacy rather than game usability, experience feedback, and the needs of the elderly when experiencing the games. To fill this knowledge gap,...

Peripersonal space (PPS) is important for humans to perform body–environment interactions. However, many previous studies only focused on the specific direction of the PPS, such as the front space, despite suggesting that there were PPSs in all directions. We aimed to measure and compare the peri-trunk PPS in four directions (front, rear, left, and...

Pseudo physical contact is used for communication in virtual environments such as VRChat. We hypothesized that the pseudo physical contact could affect interpersonal impression and communication, and the interpersonal impression would be modulated by appearance of body or avatar type. To test these hypotheses, we performed a questionnaire survey fo...

Understanding another’s viewpoint is the ability to infer others’ minds, which is important for successful social communication. To clarify this process, we investigated whether employing a humanoid avatar as the viewpoint would facilitate an imagined perspective shift in a virtual environment. We used a task that involved reporting how an object l...

Visual perspective taking is inferring how the world looks to another person. To clarify this process, we investigated whether employing a humanoid avatar as the viewpoint would facilitate an imagined perspective shift in a virtual environment. We used a task that involved reporting how an object looks by a simple direction judgment either from the...

Tactile presentation devices using mechanical stimuli require that the stimulus elements are properly contacted with the user’s skin. Many researchers have developed various kinds of the haptic display to realize the reproduction of skin sensation. Human body has complex shapes so that it is sometimes impossible to contact between stimulus elements...

Human augmentation by using robotics has been exploring by various approaches such as Exoskeleton or Telerobotics. Furthermore, the research topic of Robotic Supernumerary Limbs (SuperLimbs) is recently studying as a novel approach for human augmentation. The research issues of SuperLimbs require perspectives and approaches in human-robot interacti...

Smartphone-based microscopy offers an inexpensive magnifying solution while downsizing its optical system and considered an easy-to-use magnifier due to its small form factor compared to conventional microscopes. However, they still suffer from difficulties before and during observation: slide preparation and position control. To address this, we i...

This paper presents an approach for coupling robotic capability with human ability in dynamic throwing motions and propose a method to control the release timing computationally. A system we developed a robotic handheld device that acts as a release controller. We conducted user studies to validate clarify related technical issues to be tackled. We...

In this study, we design the distributed type haptic device using rotational stimulus elements based on perceptual experiments. Today, haptic presentation play important role in teleoperation and VR applications. Previous research propose the method of haptic presentation using multiple twist stimulus elements. In this paper, we report the design m...

Cyber space enables us to “share” bodies whose movements are a consequence of movements by several individuals. But whether and how our motor behavior is affected during body sharing remains unclear. Here we examined this issue in arm reaching performed by a shared avatar, whose movement was generated by averaging the movements of two participants....

When human movement is assisted or controlled with a muscle actuator, such as electrical muscle stimulation, a critical issue is the integration of such induced movement with the person’s motion intention and how this movement then affects their motor control. Towards achieving optimal integration and reducing feelings of artificiality and enforcem...

An activity in a well-designed virtual environment can provide both a short-term emotional impression and an immersive experience related to personal and cultural experience. In this study, we dissect the “Coming-of-Sixteen” (COS) ritual, a local rite of passage that derives from the Tainan city of Taiwan, and meticulously select kayaking activity...

Illusory body ownership can be induced in a body part or a full body by visual-motor synchronisation. A previous study indicated that an invisible full body illusion can be induced by the synchronous movement of only the hands and feet. The difference between body part ownership and the full body illusion has not been explained in detail because th...

Illusory ownership can be induced in a virtual body by visuo-motor synchrony. Our aim was to test the possibility of a re-association of the right thumb with a virtual left arm and express the illusory body ownership of the re-associated arm through a synchronous or asynchronous movement of the body parts through action and vision. Participants fel...