Meet Me Halfway: Eye Behaviour as an Expression of Robot's Language

Eye contact is a crucial behaviour in human communication and therefore an essencial feature in humanrobot interaction. A study regarding the development of an eye behaviour model for a robotic tutor in a taskoriented environment is presented, along with a description of how our proposed model is being used to implement an autonomous robot in the EMOTE project. From Sci Fi movies and books, robots are becoming a real part of human lives. The field of robotics is widespreading and new forms of robots are being designed and created to interact with people everyday in our society, forcing to consider its social status. Nowadays, different types of robots are becoming real. According to a recent survey of The United Nations, robots can be grouped into three major categories: industrial robots, professional service robots, and personal service robots (Bartneck et al. 2007), accommodating several human requirements in various environments such as factories, battlefield, home, school, and so on. This way, according to the desired environment for the robot, different types of artificial intelligence (AI) are developed in order to express different types of behaviours and communication attending to the robot embodiment and perceptive capacities (e.g., industrial robots, contrary to social robots, do not interact with people and mostly serve to do heavy work in a factory). Since gaze is literally the first contact with another being, the exchange that takes place will often determine the first impression and play a role on the interaction flow (Collier 1985). In human-robot interaction (HRI) the head is implicitly the primary place for social interaction, and the eyes are an important communication feature, having a pragmatic design goal (DiSalvo et al. 2002). This has been leading most robot manufacturers to include eyes in the robots’ design. Thus, this paper focuses on eye behaviour as a feature of Robot Language and its implication in HRI. The eyes are the mirror of the soul Eye behaviour (EB) is one of the first most meaningful and critical non-verbal behaviour for social interaction (Cassell et al. 1994) and is indeed a crucial communication cue when Copyright c © 2014, Association for the Advancement of Artificial Intelligence (www.aaai.org). All rights reserved. Figure 1: (a)Mutual Eye Contact (b)Mutual Eye Gaze looking at HRI (Mutlu, Shiwa, and Kanda 2009). As humans and robots will share their physical space, EB emerges as a way of narrowing this communication, making the interaction seem more natural, intuitive, and engaging. In general terms, research shows that there are different types of EB (Lance and Marsella 2007) that comprise a set of properties (Lee et al. 2007) to serve different functions in the social interaction (Argyle et al. 1973). In this sense, the EB is interrelated with a context and has a role in cognitive, communicative and affective face-to-face interactions, where different EB patterns can emerge (Lee et al. 2007). Thereafter, EB can be of different types: there is a distinction between eye gaze (looking at the eyes of someone) and eye contact (establishing gaze that does not necessarily target eyes), that can also happen during mutual EB (Collier 1985) (see Fig.1a, 1b). On the other hand, when we intentionally redirect our gaze away from a face, we are performing gaze aversion which in the social context is related with cognitive, intimacy-modulating, and floor management functions (Andrist et al. 2014). Timing is also essential to interpret EB (Collier 1985). This literature serves to show the complexity of EB and the inherent challenges that the HRI field still needs to overcome to achieve a truly positive social interaction between a human and a robot. To achieve this stand, we propose a different perspective regarding robot’s communicative and expressive behaviour: since robots have different embodiments that constrain their expressive modalities, they should have a specific language that is adequate for their expression. We believe that by providing robots with their own communicative and expressive language, they will not be seen as ”limited humans”, but rather as different entities. Being EB the modality that most stands out in any type of social interaction, this type of behaviour has become our starting point. Figure 2: Eye Behaviour Study Setup (a b) Figure 3: Example of the gaze-glance-gaze dynamic