Affective brain-computer interfaces (BCI) harness Neuroscience knowledge to develop affective interaction from first principles. In this article, we explore affective engagement with a virtual agent through Neurofeedback (NF). We report an experiment where subjects engage with a virtual agent by expressing positive attitudes towards her under a NF paradigm. We use for affective input the asymmetric activity in the dorsolateral prefrontal cortex (DL-PFC), which has been previously found to be related to the high-level affective-motivational dimension of approach/avoidance. The magnitude of left-asymmetric DL-PFC activity, measured using functional near infrared spectroscopy (fNIRS) and treated as a proxy for approach, is mapped onto a control mechanism for the virtual agent’s facial expressions, in which action units (AUs) are activated through a neural network. We carried out an experiment with 18 subjects, which demonstrated that subjects are able to successfully engage with the virtual agent by controlling their mental disposition through NF, and that they perceived the agent’s responses as realistic and consistent with their projected mental disposition. This interaction paradigm is particularly relevant in the case of affective BCI as it facilitates the volitional activation of specific areas normally not under conscious control. Overall, our contribution reconciles a model of affect derived from brain metabolic data with an ecologically valid, yet computationally controllable, virtual affective communication environment.

Although the Internet has become a major source for accessing news, there is little research regarding users' experience with news sites. We conducted an experiment to test a comprehensive model of user experience with news sites that was developed previously by means of an online survey. Level of adoption (novel or adopted site) was controlled with a between-subjects manipulation. We collected participants' answers to psychometric scales at 2 times: after presentation of 5 screenshots of a news site and directly after 10 minutes of hands-on experience with the site. The model was extended with the prediction of users' satisfaction with news sites as a high-level design goal. A psychometric measure of trust in news providers was developed and added to the model to better predict people's intention to use particular news sites. The model presented in this article represents a theoretically founded, empirically tested basis for evaluating news websites, and it holds theoretical relevance to user-experience research in general. Finally, the findings and the model are applied to provide practical guidance in design prioritization. IntroductionNews media have had a constantly increasing web presence since the middle of the 1990s, when most of the major news providers in the Western world launched online versions of their newspapers. More recently, with the rapid spread of handheld electronic devices, such as tablet computers, smart phones, and e-book readers, online publishing has become a major source of media use. For example, by August 2012, sales of electronic books on Amazon surpassed those of print books by 14%, including print books with no electronic editions and excluding free electronic books (Malik, 2012). With regard to the decline of print news publishing in the United States, Mitchell and Rosenstiel (2012) report that, in 2011, losses in print advertising revenue outweighed gains in online advertising revenue 10 to 1, and that in terms of the combined circulation and advertising revenue, the print-newspaper sector has shrunk by 43% since 2000. The increase in the use of online news, as opposed to print news, is not attributable only to the spread of Internet-enabled handheld devices. Mitchell and Rosenstiel also point out that 8 in 10 people who access news on smart phones or tablets also access news on conventional computers. News sites are becoming the primary source of accessing news and daily information. The success of interactive products, such as news sites, is largely influenced by the extent to which they promote positive experiences in their users (Law & van Schaik, 2010). Indeed, research in user experience (UX) is primarily motivated by the notion that high-quality experiences with interactive products promote the adoption and repeated use of these products (Hassenzahl, 2003). Model of UX with News SitesNews sites differ from other types of websites in many aspects, which carry important implications to their use, experience of use, evaluation, and quality criteria. News sites are a specific ...

Telephone: +44 1642 342320Modeling user-experience with news Web sites 2 ABSTRACT Although news Web sites are used by a large and increasing number of people, there is a lack of research within human-computer interaction regarding users' experience with this type of interactive technology. In the current research, existing measures to user-experience factors were identified and, using an online survey, answers to psychometric scales to measure Web-site characteristics, need fulfilment, affective reactions, and constructs of technology acceptance and userexperience were collected from regular users of news sites. A comprehensive userexperience model was formulated to explain acceptance and quality judgements of news sites. The main contribution of the current study is the application of influential models of user-experience and technology acceptance to the domain of online news.By integrating both types of variable in a comprehensive model, the relationships between the types of variable are clarified both theoretically and empirically. Implications of the model for theory, further research and system design are discussed.

Functional near-infrared spectroscopy (fNIRS) holds increasing potential for Brain-Computer Interfaces (BCI) due to its portability, ease of application, robustness to movement artifacts, and relatively low cost. The use of fNIRS to support the development of affective BCI has received comparatively less attention, despite the role played by the prefrontal cortex in affective control, and the appropriateness of fNIRS to measure prefrontal activity. We present an active, fNIRS-based neurofeedback (NF) interface, which uses differential changes in oxygenation between the left and right sides of the dorsolateral prefrontal cortex to operationalize BCI input. The system is activated by users generating a state of anger, which has been previously linked to increased left prefrontal asymmetry. We have incorporated this NF interface into an experimental platform adapted from a virtual 3D narrative, in which users can express anger at a virtual character perceived as evil, causing the character to disappear progressively. Eleven subjects used the system and were able to successfully perform NF despite minimal training. Extensive analysis confirms that success was associated with the intent to express anger. This has positive implications for the design of affective BCI based on prefrontal asymmetry.

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