Robin L. Hill

Clustering of Gaze During Dynamic Scene Viewing is Predicted by Motion

Where does one attend when viewing dynamic scenes? Research into the factors influencing gaze location during static scene viewing have reported that low-level visual features contribute very little to gaze location especially when opposed by high-level factors such as viewing task. However, the inclusion of transient features such as motion in dynamic scenes may result in a greater influence of visual features on gaze allocation and coordination of gaze across viewers. In the present study, we investigated the contribution of low- to mid-level visual features to gaze location during free-viewing of a large dataset of videos ranging in content and length. Signal detection analysis on visual features and Gaussian Mixture Models for clustering gaze was used to identify the contribution of visual features to gaze location. The results show that mid-level visual features including corners and orientations can distinguish between actual gaze locations and a randomly sampled baseline. However, temporal features such as flicker, motion, and their respective contrasts were the most predictive of gaze location. Additionally, moments in which all viewers’ gaze tightly clustered in the same location could be predicted by motion. Motion and mid-level visual features may influence gaze allocation in dynamic scenes, but it is currently unclear whether this influence is involuntary or due to correlations with higher order factors such as scene semantics.

Introducing the Internet to the over-60s: Developing an email system for older novice computer users

Contemporary technology offers many benefits to older people, but these are often rendered inaccessible through poor software design. As the Internet increasingly becomes a source of information and services it is vital to ensure that older people can access these resources. As part of project funded by the UK government, a multi-disciplinary team set out to develop usable software that would help to introduce older people to the Internet. The first step was to develop an email system for older people with no experience of Internet use. The project was intended to show that it is possible to design usable technology for this group and to explore some of the issues involved in doing so. Design and technical challenges necessitated various tradeoffs. The system produced demonstrated the success of the design decisions: it was significantly easier to use than, and preferred to, a commercial equivalent by a group of older people with no experience of Internet use.

Keeping In Touch: Talking to Older People about Computers and Communication

Computer-based communication has tremendous potential to support older adults. But if people are to use such systems autonomously, it is necessary to move beyond current interfaces and systems and develop devices that fit into the environment of the user. Using a Grounded Theory approach, three focus groups were held and, subsequently, 9 older adults (age 70–90) were interviewed about the ways in which they kept in touch with friends and relatives. Outcomes included dependence on the telephone as a way of communicating. There is also a specific, supporting role for e-mail, which was used with younger family members or those living abroad to enrich communication with brief, informal messages.

The roles of haptic-ostensive referring expressions in cooperative, task-based human-robot dialogue

Generating referring expressions is a task that has received a great deal of attention in the natural-language generation community, with an increasing amount of recent effort targeted at the generation of multimodal referring expressions. However, most implemented systems tend to assume very little shared knowledge between the speaker and the hearer, and therefore must generate fully-elaborated linguistic references. Some systems do include a representation of the physical context or the dialogue context; however, other sources of contextual information are not normally used. Also, the generated references normally consist only of language and, possibly, deictic pointing gestures. When referring to objects in the context of a task-based interaction involving jointly manipulating objects, a much richer notion of context is available, which permits a wider range of referring options. In particular, when conversational partners cooperate on a mutual task in a shared environment, objects can be made accessible simply by manipulating them as part of the task. We demonstrate that such expressions are common in a corpus of human-human dialogues based on constructing virtual objects, and then describe how this type of reference can be incorporated into the output of a humanoid robot that engages in similar joint construction dialogues with a human partner.

Eyetracking for two-person tasks with manipulation of a virtual world.

Eyetracking facilities are typically restricted to monitoring a single person viewing static images or prerecorded video. In the present article, we describe a system that makes it possible to study visual attention in coordination with other activity during joint action. The software links two eyetracking systems in parallel and provides an on-screen task. By locating eye movements against dynamic screen regions, it permits automatic tracking of moving on-screen objects. Using existing SR technology, the system can also cross-project each participant’s eyetrack and mouse location onto the other’s on-screen work space. Keeping a complete record of eyetrack and on-screen events in the same format as subsequent human coding, the system permits the analysis of multiple modalities. The software offers new approaches to spontaneous multimodal communication: joint action and joint attention. These capacities are demonstrated using an experimental paradigm for cooperative on-screen assembly of a two-dimensional model. The software is available under an open source license.

Commas and Spaces: Effects of Punctuation on Eye Movements and Sentence Parsing

While it has been widely assumed that punctuation may play a critical role in reading, there has been relatively little direct empirical investigation of its effects on the process in general or eye movements in particular. Most research on sentence parsing has either avoided the use of punctuation or simply assumed that it necessarily serves a disambiguating role. There has been little or no consideration of how ‘disambiguation’ might occur or of the precise nature of the effects that punctuation might have on the reading process. Previous work using self-paced reading (Hill and Murray, 1997a, b) has in fact shown that simplistic assumptions related to the disambiguating effect of punctuation cannot be supported. These studies demonstrated that while punctuation plays a potent disambiguating role in some structures, the effect is by no means universal. It remained unclear, however, whether these conclusions could be generalised to a more natural reading situation and whether eye-movement patterns while reading punctuated text provide an insight into the underlying parsing mechanisms. In this chapter we discuss more recent studies which have extended this work by monitoring subjects’ eye movements while reading exemplars of three types of locally ambiguous items with and without inserted punctuation. In order to control for simple oculomotor effects related to the additional spacing associated with punctuation, the studies also included a condition with equivalent spacing but without punctuation. The results show potent effects of punctuation on the first-pass processing of two structures (early-closure and reduced relative-clause constructions), but not in the ‘preferred’ versions of either of these and not in sentences containing prepositional phrase ambiguities. Punctuation also exerted effects on local processing difficulty, suggesting that it cues parsing decisions at particular points in a sentence. Frequently, inserted punctuation increased processing time on sections of a sentence immediately preceding a comma, while facilitating the processing which followed. The focus of this chapter, however, is on the effects of punctuation on eye-movement parameters in punctuated and unpunctuated sentences, the ways in which these differ from unpunctuated sentences with equivalent spacing and the extent to which they reflect the processing consequences of punctuation and spacing. It was found that punctuation and increased spacing between words had similar effects on the pattern of eye movements with increases in saccade extent of more than the added character space, but this similarity was not mirrored in equivalent effects on reading time and disambiguation. Punctuation therefore appears to convey information related to structure that is more potent than the simple ‘chunking’ of text, but this effect is limited to particular structural conditions. The results also suggest a dissociation between some eye-movement parameters and their consequences for underlying sentence processing.

Older web users' eye movements: experience counts

Eye-tracking is a valuable tool for usability research. Studies into the effect of age on eye-movement behavior tend to indicate a propensity for slower viewing and longer times spent examining information. This pattern is usually attributed to the general physiological and cognitive slow-down associated with normal aging. In this paper, however, across three different tasks based on computer and internet use (free-viewing, visual search, and browser interaction), we show that among older adults (n=18, age range: 70-93) computer experience appears to be a highly important factor in eye-movement behavior. We argue that as a consequence of the experimental environment used in modern eye-tracking studies, characteristics such as familiarity and experience with computers should be taken into account before conclusions are drawn about the raw effects of age.

Eye-movement research

Publisher Summary This chapter discusses some of the issues that reflect the wide diversity of eye-movement research. It provides an up-to-date impression of the most significant developments in the area, based on findings from a survey of eye-movement researchers and database searches. Recent developments include the history of eye-movement research, eye movements as a method for investigating spoken language processing, and eye movements in natural environments. The modeling of eye movements has also seen a great deal of recent change and development. Areas that have been longer established but continue to produce important new findings are physiology and clinical studies of eye movements, transsaccadic integration, eye-movements and reading, and eye movements as a method for investigating attention and scene perception. The most important developments in eye-movement research have been highlighted. The chapter considers the state of eye-movement research by reporting results from a survey sent to participants of The 12th European Conference on Eye Movements (ECEM12) and a journal database search. The chapter describes computational modeling, new eye-tracking technologies, and anatomical and physiological mapping of the visual-oculomotor system as the most important recent developments.

Tuning accessibility of referring expressions in situated dialogue

Accessibility theory associates more complex referring expressions with less accessible referents. Felicitous referring expressions should reflect accessibility from the addressees perspective, which may be difficult for speakers to assess incrementally. If mechanisms shared by perception and production help interlocutors align internal representations, then dyads with different roles and different things to say should profit less from alignment. We examined introductory mentions of on-screen shapes within a joint task for effects of access to the addressees attention, of players’ actions and of speakers’ roles. Only speakers’ actions affected the form of referring expression and only different role dyads made egocentric use of actions hidden from listeners. Analysis of players’ gaze around referring expressions confirmed this pattern; only same role dyads coordinated attention as the accessibility theory predicts. The results are discussed within a model distributing collaborative effort under the constraints of joint tasks.

Eye-movement research: An overview of current and past developments

Publisher Summary This chapter discusses some of the issues that reflect the wide diversity of eye-movement research. It provides an up-to-date impression of the most significant developments in the area, based on findings from a survey of eye-movement researchers and database searches. Recent developments include the history of eye-movement research, eye movements as a method for investigating spoken language processing, and eye movements in natural environments. The modeling of eye movements has also seen a great deal of recent change and development. Areas that have been longer established but continue to produce important new findings are physiology and clinical studies of eye movements, transsaccadic integration, eye-movements and reading, and eye movements as a method for investigating attention and scene perception. The most important developments in eye-movement research have been highlighted. The chapter considers the state of eye-movement research by reporting results from a survey sent to participants of The 12th European Conference on Eye Movements (ECEM12) and a journal database search. The chapter describes computational modeling, new eye-tracking technologies, and anatomical and physiological mapping of the visual-oculomotor system as the most important recent developments.