Ewa Lux

Remote heart rate measurement using low-cost RGB face video: a technical literature review

Remote photoplethysmography (rPPG) allows remote measurement of the heart rate using low-cost RGB imaging equipment. In this study, we review the development of the field of rPPG since its emergence in 2008. We also classify existing rPPG approaches and derive a framework that provides an overview of modular steps. Based on this framework, practitioners can use our classification to design algorithms for an rPPG approach that suits their specific needs. Researchers can use the reviewed and classified algorithms as a starting point to improve particular features of an rPPG algorithm.

Colors and Trust: The Influence of User Interface Design on Trust and Reciprocity

Interpersonal trust and reciprocation are crucial factors in peer-to-peer online interactions. In order to shed more light on the association of user interface (UI) design and trusting as well as reciprocating behavior, we consider a computerized trust game with different interface background colors, red and blue, namely. We locate our work within recent NeuroIS theory, linking UI background color to user behavior via perceived warmth of UIs and color appeal. The results of a laboratory experiment indicate an enhancing effect of red interfaces on reciprocation behavior, fully mediated by perceived warmth. We suggest to further investigate this phenomenon by applying NeuroIS methodology.

Bidding Behavior in Dutch Auctions: Insights from a Structured Literature Review

ABSTRACT The Dutch auction, also known as the descending-price auction or reverse clock auction, has a long-standing history in practice and in academic literature. In practice, the Dutch auction is commonly used to rapidly sell large quantities of homogeneous goods, such as cut flowers, fish, or tobacco. However, most e-commerce auction sites focus on other auction mechanisms, and overall research on human behavior in Dutch auctions is scant. To facilitate research on Dutch auctions and their applications in electronic commerce, we conduct a structured literature review of experimental studies and establish the current state of research on bidding behavior in single-unit and multi-unit Dutch auctions. The findings are based on an analysis of twenty-nine articles published in the fields of economics, information management, marketing, and operations research and management science between 1970 and 2016. This review reveals (1) the characteristics that make the Dutch auction unique compared to other auction formats, (2) the drivers of bidding behavior in Dutch auctions, and (3) an overview of how Dutch auctions can be employed in practice and to what advantage. Finally, we identify directions for future research on bidding behavior in Dutch auctions.

Using Contactless Heart Rate Measurements for Real-Time Assessment of Affective States

Heart rate measurements contain valuable information about a person’s affective state. There is a wide range of application domains for heart rate-based measures in information systems. To date, heart rate is typically measured using skin contact methods, where users must wear a measuring device. A non-contact and easy to use mobile approach, allowing heart rate measurements without interfering with the users’ natural environment, could prove to be a valuable NeuroIS tool. Hence, our two research objectives are (1) to develop an application for mobile devices that allows for non-contact, real-time heart rate measurement and (2) to evaluate this application in an IS context by benchmarking the results of our approach against established measurements. The proposed algorithm is based on non-contact photoplethysmography and hence takes advantage of slight skin color variations that occurs periodically with the user’s pulse.

Live Biofeedback in Electronic Markets

Decisions in electronic markets are frequently made under time pressure and in competition to others. Both factors can cause the decision maker to experience high levels of arousal. Without sound emotional processing, arousal can have detrimental effects on decision making. In this thesis the use of live biofeedback to support emotion perception and thus, to facilitate emotion regulation during emotionally charged decision making is evaluated. Based on a systematic literature review existing live biofeedback research is analyzed in Chapter 2. A transmission model for live biofeedback is developed that classifies the main components of live biofeedback applications and the flow of information in form of transmission signals. To address the identified research gaps, three experimental studies (study I-III) are designed that investigate the effects of arousal and the use of live biofeedback in electronic markets. Study I in Chapter 3 examines how arousal affects purchasing decisions with and without social interaction to analyze the context dependence of the effects of arousal on decision making. The results reveal that in auctions, where social interaction is a key characteristic, arousal increases final prices. Purchasing decisions without social interaction, however, are not affected by arousal. As social interaction has been identified as an essential factor for arousal to affect decision making, the subsequent studies II and III investigate the effects of live biofeedback in markets experiments that involve social interaction. Study II in Chapter 4 evaluates the effects of live biofeedback on emotional processing in the context of auction bidding. Without prior biofeedback training this novel user interface element alters decision making processes at a cognitive and affective level. Study participants, who suppress emotional expressions, experience higher levels of physiological arousal. When provided with live biofeedback, this effect is mitigated. Furthermore, participants who receive live biofeedback show increased coherence of physiological and perceived arousal. Study III in Chapter 5 examines the use of biofeedback in a game that has frequently been used to model financial markets, that is, the beauty contest game. In this study, participants complete a training in order to familiarize with the live biofeedback prior to the experiment. The analysis reveals that live biofeedback increases arousal perception and reduces suppression of emotional expressions. Importantly, participants who receive live biofeedback yield higher decision making quality. In summary, this thesis provides further insights into the effects of arousal on behavior and how live biofeedback affects emotional processing and decision making in electronic markets. The results of this thesis suggest that live biofeedback is a promising tool to support emotion perception, regulation, and decision making of market participants.

A Hot Topic—Group Affect Live Biofeedback for Participation Platforms

Emotions are omnipresent in our lives. They influence our health, decision making, and social interactions—bilateral as well as multilateral. Hence also modern forms of opinion building and exchange, e.g., on e-participation platforms, should consider the effects of emotions on individual and group level. Previous research on group interactions demonstrated that providing the members with information about the affective state of the entire group, reciprocally influences the affective states of the individuals and can even increase group performance. Hence, in the current short paper we propose group affect live biofeedback (LBF) as a beneficial feature for e-participation platforms. We want to examine how group affect LBF based on the participant’s heart rate impacts participation behavior.

Foreign Live Biofeedback: Using Others’ Neurophysiological Data

Advances in sensor technology and real-time analysis of neurophysiological data have enabled the use of live biofeedback in information systems and the development of neuro-adaptive information systems. In this article, we transfer this notion to the use of foreign neurophysiological data. We sketch out an experimental approach and research model for investigating the impact of such foreign data in a trust scenario. We argue that foreign live biofeedback may be a powerful means to establish social presence and thus trust among the parties. Moreover, we discuss controversies such technology is likely to raise and sketch out potential strategies for IS service providers in this regard.