This chapter describes how intelligent embodied agents may react according to end-users' attention states and how these agents may adapt their interventions to encourage end users to participate actively in virtual environments such as collaboration platforms or e-learning modules. Attention-related data are taken into account by adapting generically defined interventions (templates) to particular contexts through the use of scripting and markup languages. This chapter introduces the Living Actor™ technology, whose main purpose is to provide end users with high-quality adaptive embodied agents, or avatars. Living Actor™ technology receives input from software components' reasoning on users' attention states and adjusts the actions of its embodied agents. The result is the creation of embodied agents, or avatars, that are capable of natural, intuitive, autonomous and adaptive behaviours that account for variations in emotion, gesture, mood, voice, culture and personality.

Introduction

According to Gartner (April 2007), by the end of 2011, 80 per cent of active Internet users (and Fortune 500 enterprises) will have a ‘second life’, not necessarily in the virtual world, called Second Life. Users' virtual lives will be represented by embodied agents in the form of avatars, or virtual representations of the self which allow users to express themselves with a personalized identity of their own creation. In the present chapter the authors define agents as ‘soft- and/or hardware that is intended to represent a complete person, animal, or personality’ (Sengers 2004: 4).

This chapter presents a number of software applications that make use of an eye tracker. It builds on the knowledge of visual attention and its control mechanisms as presented in chapters 3 and 5. It provides a tour through the years, showing how the use of eye gaze as indicator of visual attention has developed from being an additional input modality, supporting the disambiguation of fuzzy signals, to an interaction enhancement technique that allows software systems to work proactively and retrieve information without the user giving explicit commands.

Introduction

Our environment provides far more perceptual information than can be effectively processed. Hence, the ability to focus our attention on the essential is a crucial skill in a world full of visual stimuli. What we see is determined by what we attend to: the direction of our eye gaze, the focus of our visual attention, has a close relationship with the focus of our attention.

Eye trackers, which are used to measure the point of gaze, have developed rapidly during recent years. The history of eye-tracking equipment is long. For decades, eye trackers have been used as diagnostic equipment in medical laboratories and to enable and help communication with severely disabled people (see, e.g., Majaranta and Räihä 2007). Only recently have eye trackers reached the level of development where they can be considered as input devices for commonly used computing systems.

In recent years it has been increasingly recognized that the advent of information and communication technologies has dramatically shifted the balance between the availability of information and the ability of humans to process information. During the last century information was a scarce resource. Now, human attention has become the scarce resource whereas information (of all types and qualities) abounds. The appropriate allocation of attention is a key factor determining the success of creative activities, learning, collaboration and many other human pursuits. A suitable choice of focus is essential for efficient time organization, sustained deliberation and, ultimately, goal achievement and personal satisfaction. Therefore, we must address the problem of how digital systems can be designed so that, in addition to allowing fast access to information and people, they also support human attentional processes. With the aim of responding to this need, this book proposes an interdisciplinary analysis of the issues related to the design of systems capable of supporting the limited cognitive abilities of humans by assisting the processes guiding attention allocation. Systems of this type have been referred to in the literature as Attention-Aware Systems (Roda and Thomas 2006), Attentive User Interfaces (Vertegaal 2003) or Notification User Interfaces (McCrickard, Czerwinski and Bartram 2003) and they engender many challenging questions (see, for example, Wood, Cox and Cheng 2006).

This chapter reviews the results of the Salience Project, a cross-disciplinary research project focused on understanding how humans direct attention to salient stimuli. The first objective of the project was theoretical: that is, to understand behaviourally and electrophysiologically how humans direct attention through time to semantically and emotionally salient visual stimuli. Accordingly, we describe the glance-look model of the attentional blink. Notably, this model incorporates two levels of meaning, both of which are based upon latent semantic analysis, and, in addition, it incorporates an explicit body-state subsystem in which emotional experience manifests. Our second major objective has been to apply the same glance-look model to performance analysis of human–computer interaction. Specifically, we have considered a class of system which we call stimulus-rich reactive interfaces (SRRIs). Such systems are characterized by demanding (typically) visual environments, in which multiple stimuli compete for the user's attention, and a variety of physiological measures are employed to assess the user's cognitive state. In this context, we have particularly focused on electroencephalogram (EEG) feedback of stimulus perception. Moreover, we demonstrate how the glance-look model can be used to assess the performance of a variety of such reactive computer interfaces. Thus, the chapter contributes to the study of attentional support and adaptive interfaces associated with digital environments.

Introduction

Humans are very good at prioritizing competing processing demands. In particular, perception of a salient environmental event can interrupt ongoing processing, causing attention, and accompanying processing resources, to be redirected to the new event.