Alan Lindsay

Subliminal cueing of selection behavior in a virtual environment

The performance of current graphics engines makes it possible to incorporate subliminal cues within virtual environments (VEs), providing an additional way of communication, fully integrated with the exploration of a virtual scene. In order to advance the application of subliminal information in this area, it is necessary to explore in the psychological literature how techniques previously reported as rendering information subliminal can be successfully implemented in VEs. Previous literature has also described the effects of subliminal cues as quantitatively modest, which raises the issue of their inclusion in practical tasks. We used a 3D rendering engine (Unity3D) to implement a masking paradigm within the context of a realistic scene and a familiar (kitchen) environment. We report significant effects of subliminal cueing on the selection of objects in a virtual scene, demonstrating the feasibility of subliminal cueing in VEs. Furthermore, we show that multiple iterations of masked objects within a trial, as well as the speeding of selection choices, can substantially reinforce the impact of subliminal cues. This is consistent with previous findings suggesting that the effect of subliminal stimuli fades rapidly. We conclude by proposing, as part of further work, possible mechanisms for the inclusion of subliminal cueing in intelligent interfaces to maximize their effects.

Covert Persuasive Technologies: Bringing Subliminal Cues to Human-Computer Interaction

The capability of machines to covertly persuade humans is both exciting and ethically concerning. In the present study we aim to bring subliminal masked stimulus paradigms to realistic environments, through Virtual Environments. The goal is to test if such paradigms are applicable to realistic setups while identifying the major challenges when doing so. We designed a study in which the user performed a realistic selection task in a virtual kitchen. For trials below one-second reaction time, we report significant effect of subliminal cues on the selection behavior. We conclude the study with a discussion of the challenges of bringing subliminal cueing paradigms to realistic HCI setups. Ethical concerns when designing covertly persuasive systems are discussed as well.

Generation of Non-compliant Behaviour in Virtual Medical Narratives

Patient education documents increasingly take the form of Patient Guidelines, which share many of the properties of clinical guidelines in terms of knowledge content and the description of clinical protocols. They however differ in one specific aspect, which is that some recommendations for patient behaviour may be violated, and that no explicit representation of undesired behaviour is embedded in the guidelines themselves. In this paper, we take as a starting point the plan-based representation of clinical guidelines, which has been promoted by several authors, and introduce a method to automatically derive the set of “opposite actions” that constitute violations of recommended patient behaviours. These additional alternative actions are generated automatically as PDDL operators complementing the description of the guideline. As an application, using a patient guideline on bariatric surgery, we also present examples of how these actions can be used to visualise undesirable patient behaviour in a 3D serious game, featuring virtual agents representing the patient and healthcare professionals.

An Innovative Heuristic for Planning-Based Urban Traffic Control

The global growth in urbanisation increases the demand for services including road transport infrastructure, presenting challenges in terms of mobility. In this scenario, optimising the exploitation of urban road network is a pivotal challenge, particularly in the case of unexpected situations. In order to tackle this challenge, approaches based on mixed discrete-continuous planning have been recently proposed and although their feasibility has been demonstrated, there is a lack of informative heuristics for this class of applications. Therefore, existing approaches tend to provide low-quality solutions, leading to a limited impact of generated plans on the actual urban infrastructure.

Visualization of Patient Behavior from Natural Language Recommendations

The visualization of procedural knowledge from textual documents using 3D animation may be a way to improve understanding. We are interested in applying this approach to documents relating to patient education for bariatric surgery: a domain with challenging textual documents describing behavior recommendations that contain few procedural steps and leave much commonsense knowledge unspecified. In this work we look at how to automatically capture knowledge from a range of differently phrased recommendations and use that with implicit knowledge about compliance and violation, such that the recommendations can be visualized using 3D animations. Our solution is an end-to-end system that automates this process via: analysis of input recommendations to uncover their conditional structure; the use of commonsense knowledge and deontic logic to generate compliance and violation rules; and mapping of this knowledge to update a default knowledge base, which is used to generate appropriate sequences of visualizations. In this paper we overview this approach and demonstrate its potential.

An Interactive Narrative Format for Clinical Guidelines

Clinical guidelines are standardised documents, which summarise best practice in complex medical situations. Their target audience comprises health professionals, or in some cases patient groups, for whom they constitute important sources of patient education. These documents are characterised by a rich knowledge content, which also relies on a complex, largely implicit background. At the heart of guidelines is a set of recommendations describing expected behaviour throughout specific, evolving contexts. Such complex documents can be challenging to assimilate, in particular their patient education versions. The need to contextualise information and visualise behaviours and their consequences suggests the use of virtual environments, as in serious gaming. However, knowledge representation in serious games are often limited and the overall implementation mainly empirical. On the other hand, interactive narratives technologies have demonstrated their ability to embed complex behavioural knowledge and support principled behaviour responding to dynamic contexts. This is why they support the exploration of complex situations, their rehearsal, and the understanding of expected behaviour through what-if interaction. The narrative perspective also provides better user guidance than a pure simulation system, allowing mixed-initiative access to information. The translation of medical protocols as interactive narratives is faced with a number of knowledge representation challenges, in particular for the representation of non-compli-ance and the consequences of incorrect behaviour. Another technical issue is the need to represent both common sense and domain knowledge, and articulate their representation with the Planning domain that forms the backbone of the interactive narrative. As part of the Open FET project MUSE (FP7-296703), we are developing a proof-of-concept prototype exploring the above aspects, and embedding the logical structure of guidelines into a real-time interactive narrative, which provides a principled simulation of the situations faced by patients, which preserves causal and deontic constraints. This paper describes the knowledge engineering process supporting the development of this prototype, from the analysis of patient guidelines to the use of planning representations supporting the interactive narrative.