Hideki Kozima

Keepon : A Playful Robot for Research, Therapy, and Entertainment (Original Paper)

Keepon is a small creature-like robot designed for simple, natural, nonverbal interaction with children. The minimal design of Keepon’s appearance and behavior is meant to intuitively and comfortably convey the robot’s expressions of attention and emotion. For the past few years, we have been observing interactions between Keepon and children at various levels of physical, mental, and social development. With typically developing children, we have observed varying styles of play that suggest a progression in ontological understanding of the robot. With children suffering from developmental disorders such as autism, we have observed interactive behaviors that suggest Keepon’s design is effective in eliciting a motivation to share mental states. Finally, in developing technology for interpersonal coordination and interactional synchrony, we have observed an important role of rhythm in establishing engagement between people and robots. This paper presents a comprehensive survey of work done with Keepon to date.

TEXT SEGMENTATION BASED ON SIMILARITY BETWEEN WORDS

This paper proposes a new indicator of text structure, called the lexical cohesion profile (LCP), which locates segment boundaries in a text. A text segment is a coherent scene; the words in a segment are linked together via lexical cohesion relations. LCP records mutual similarity of words in a sequence of text. The similarity of words, which represents their cohesiveness, is computed using a semantic network. Comparison with the text segments marked by a number of subjects shows that LCP closely correlates with the human judgments. LCP may provide valuable information for resolving anaphora and ellipsis.

Children-robot interaction: a pilot study in autism therapy.

We present here a pilot study of child-robot interactions, in which we discuss developmental origins of human interpersonal communication. For the past few years, we have been observing 2- to 4-year-old children with autism interacting with Keepon, a creature-like robot that is only capable of expressing its attention (directing its gaze) and emotions (pleasure and excitement). While controlled by a remote experimenter, Keepon interacted with the children with its simple appearance and actions. With a sense of curiosity and security, the children spontaneously approached Keepon and engaged in dyadic interaction with it, which then extended to triadic interactions where they exchanged with adult caregivers pleasure and surprise they found in Keepon. Qualitative and quantitative analysis of these unfolding interactions suggests that autistic children possess the motivation to share mental states with others, which is contrary to the commonly held position that this motivation is impaired in autism. We assume Keepons minimal expressiveness helped the children understand socially meaningful information, which then activated their intact motivation to share interests and feelings with others. We conclude that simple robots like Keepon would facilitate social interaction and its development in autistic children.

Similarity between words computed by spreading activation on an English dictionary

This paper proposes a method for measuring semantic similarity between words as a new tool for text analysis. The similarity is measured on a semantic network constructed systematically from a subset of the English dictionary, LDOCE (Longman Dictionary of Contemporary English). Spreading activation on the network can directly compute the similarity between any two words in the Longman Defining Vocabulary, and indirectly the similarity of all the other words in LDOCE. The similarity represents the strength of lexical cohesion or semantic relation, and also provides valuable information about similarity and coherence of texts.

A dancing robot for rhythmic social interaction

This paper describes a robotic system that uses dance as a form of social interaction to explore the properties and importance of rhythmic movement in general social interaction. The system consists of a small creature-like robot whose movement is controlled by a rhythm-based software system. Environmental rhythms can be extracted from auditory or visual sensory stimuli, and the robot synchronizes its movement to a dominant rhythm. The system was demonstrated, and an exploratory study conducted, with children interacting with the robot in a generalized dance task. Through a behavioral analysis of videotaped interactions, we found that the robots synchronization with the background music had an effect on childrens interactive involvement with the robot. Furthermore, we observed a number of expected and unexpected styles and modalities of interactive exploration and play that inform our discussion on the next steps in the design of a socially rhythmic robotic system.

Measurements of reflection characteristics and refractive indices of interior construction materials in millimeter-wave bands

The reflection characteristics and refractive indices of construction materials in the millimeter wave bands are needed for development of millimeter-wave application systems such as indoor communication systems and short-range sensing systems. Because so little experimental data of construction materials at millimeter-wave bands has been available, the authors have measured the reflection and transmission coefficients of a concrete plate, plasterboard, rock wool, a floorboard, a carpet tile, at 57.5, 78.5, and 95.9 GHz. The refractive indices of the materials that can be modeled as a homogeneous dielectric plate with a smooth surface were estimated by the combined use of reflection and transmission data. The refractive indices of a concrete plate, plasterboard, a floorboard, and rock wool at 57.5 GHz were found to be 2.55-j0.084, 1.50-j0.01, 1.98-j0.083, and 1.26-j0.005, respectively. These indices showed little frequency dependence in the measured frequency range, except for that of the floorboard, which varied about 10%. The authors also measured the reflection characteristics of materials with inhomogeneous structures or rough surfaces, and found that the specular reflection from a concrete plate and a floorboard can be reduced significantly by covering them with carpet tiles with rough surfaces.

Can a robot empathize with people

This article explores a robotogenetic model of empathetic understanding of another mind as one of the capabilities required in human–robot social interactions. The term “robotogenetic” means that we implement a possible ontogeny (i.e., developmental process) of the social capability onto a robotic embodiment with a certain phylogenetic background (i.e., innate prerequisites). First, we look into infants’ development of social and communicative skills, especially of empathetic understanding of others. We then consider two fundamental abilities, namely eye-contact and joint attention, as the prerequisites for this cognitive development. Then in psychological experiments using robots that are capable of eye-contact and joint attention, we observe how people, especially infants and children, attribute mental states to the robots. Based on these investigations, we consider a possible mechanism of empathy which is based on the spatiotemporal coordination of attention and bodily movement between the self and another.

Interactive Robots as Facilitators of Childrens Social Development

Early communication between a child and a caregiver is mainly embodied through touch and eyecontact, which convey various kinds of emotional information (Kaye, 1982; Trevarthen, 2001). This communication of emotion develops into joint attention (Butterworth & Jarrett, 1991), where both alternate between looking at the same object or event and looking at each other. By mutually monitoring emotions and attention in this way, the child and the caregiver share awareness of a topical target as well as emotional attitudes towards it. Thus, the child can learn the meaning and value of various objects and events in the world, which leads him or her to the acquisition of language and culture (Tomasello, 1993, 1999). With inspiration from the psychological study of social development, we have developed a childlike robot, Infanoid (Kozima, 2002), and a creature-like robot, Keepon (Kozima et al., 2004), as research platforms for testing and elaborating on psychological models of human social intelligence and its development in real-world settings. We are currently implementing on these robots software modules required for embodied interaction with people, especially with children. In addition, we are observing and analyzing social development in children when they interact with these robots. These two complementary research activities will help us to model social communication and its development during the first years of life. This paper describes design principles of interactive robots for the cognitive study of human social intelligence and for the development of pedagogical and therapeutic services for children’s social development. After reviewing recent psychological findings on children’s social development and recent advances in robotics facilitating social interaction with children, we discuss design principles that make robots capable of embodied interaction with children. We introduce our robotic platforms, Infanoid and Keepon, as examples of implementation of these design principles. We then describe how typically-developing children interact with Infanoid and Keepon, from which we model how social interaction dynamically unfolds as time passes and how such interactions qualitatively change with age. We have conducted longitudinal field observations of a group of children with developmental disorders and a group of typically-developing preschool children interacting with Keepon. We learned from these observations that an appropriately designed robot could facilitate not only dyadic interaction between a child and the robot, but also triadic interaction among children and carers, where the robot functions as a pivot of the interpersonal interactions. Finally, we discuss the possible use of interactive robots in pedagogical and therapeutic services for typically-developing children and for those with developmental disorders, especially autistic spectrum disorders.

An epigenetic approach to human-robot communication

This paper proposes a developmental approach to social intelligence, especially communication ability, for robots and other artificial systems. Any social being has to have two essential features: naturalistic embodiment, i.e., having a body similar to others; and socio-cultural situatedness, i.e., being able to communicate with others and to participate in the social activity. However, we still have an open question: how does the body become situated in the social environment? Our answer is epigenesis, where (1) we create a humanoid with minimum innate abilities, namely a primordial form of joint attention and indirect experience, then (2) through the attentional and imitative interaction with human caregivers, the humanoid autonomously explores how to interact socially with people. As an epigenetic embodiment, the authors are building an upper-torso humanoid, Infanoid, which is to acquire social situatedness in the human community.

Rhythmic attention in child-robot dance play

Human social behavior is rhythmic, and synchrony plays an important role in coordinating and regulating our interactions. We are developing technology that allows the robot Keepon to perceive and behave rhythmically, and to synchronize its dancing behaviors to music or to childrens movement as perceived using pressure sensors. We present two experiments in which Keepon dances with children to music, and in which the robots rhythmic attention and role of leader or follower are manipulated in order to examine the effects on engagement and rhythmic synchrony. We found that children can assume the roles of leader or follower in a rhythmic interaction, that followers indeed tend to synchronize with the robots movements, and that the role of follower causes the children to more closely follow a musical rhythm.