The embodied user : corporeal awareness & media technology

Human beings are proficient users of tools and technology. At times, our interactions with a technological artifact appear so effortless, that the distinction between the artifact and the body starts to fade. When operating anthropomorphically designed teleoperation systems, for example, some people develop the vivid experience that they are physically there at the remote site (i.e., telepresence). Others might even come to sense the slave robot’s arms and hands as their own. The process in which the central nervous system categorizes an object as a part of the body, and in which a discrimination is made between what is contained within and outside the bodily boundaries, is called self-attribution. The aim of this thesis is twofold: (a) To determine the personal factors (e.g., the characteristics of an individual’s psychological makeup) and situational factors (e.g., the appearance of objects) that constrain or facilitate self-attribution, and (b) to determine the degree to which these factors affect people’s experiences with media technology. In Chapter 2, we describe the theoretical framework of our research which is centered on a conception of the user of technology as an embodied agent. In this chapter we distinguish two important, but often confused aspects of embodiment: the body schema, and the body image. The body schema is defined as a dynamic distributed network of procedures aimed at guiding behavior. In contrast, we defined the body image as a part of the process of consciousness and, thus, as consisting of those higher-order discriminations (or qualia) that pertain to the body, and one’s self-perception thereof. To investigate the individual and situational factors that constrain or facilitate selfattribution (i.e., incorporation into the body image), we employ the experimental paradigm of the rubber-hand illusion (Botvinick & Cohen, 1998). In this illusion, which is induced by stroking a person’s concealed hand together with a visible fake one, some people start to sense the fake hand as an actual part of their body. In Chapter 3, we investigate the rubberhand illusion under two mediated conditions: (1) a virtual reality condition, where both the fake hand and its stimulation were projected on the table in front of the participant, and (2) a mixed reality condition, where the fake hand was projected, but its stimulation was unmediated. Our experiment reveals that people can develop the rubber-hand illusion under mediated conditions, but the resulting illusion may, depending on the technology used, be less vivid than in the traditional unmediated setup. In Chapter 4, we investigate the extent to which visual discrepancies between the foreign object and a human hand affect people in developing a vivid rubber-hand illusion. We found that people experience a more vivid illusion when the foreign object resembles the human hand in terms of both shape and texture. Taken together, the experiments in Chapters 3 and 4 support the view that the rubber-hand illusion is not merely governed by a bottom-up process (i.e., based on visuotactile integration), but is affected, top-down, by a cognitive representation of what the human body is like (e.g., Tsakiris and Haggard, 2005). In the rubber-hand illusion, people commonly misperceive the location of their concealed hand toward the direction of the fake hand (Tsakiris & Haggard, 2005). As such, this so-called proprioceptive drift is often used as an alternative to self-reports in assessing the vividness of the illusion (e.g., Tsakiris & Haggard, 2005). In Chapter 5, we investigate the extent to which the observed shift in felt position of the concealed hand can be attributed to experiencing the illusion. For this purpose, we test how various features of the experimental setup of the rubber-hand illusion, which in themselves are not sufficient to elicit the illusion, affect proprioceptive drift. We corroborate existing research which demonstrates that looking at a fake hand or a tabletop for five minutes, in absence of visuotactile stimulation, is sufficient to induce a change in the felt position of an unseen hand (e.g., Gross et al., 1974). Moreover, our experiments indicate that the use of proprioceptive drift as a measure for the strength of the rubber-hand illusion yields different conclusions than an assessment by means of self-reports. Based on these results, we question the validity of proprioceptive drift as an alternative measure of the vividness of the rubber-hand illusion. In Chapter 6, we propose and test a model of the vividness of the rubber-hand illusion. In two experiments, we successfully modeled people’s self-reported experiences related to the illusion (e.g., "the fake hand felt as my own") based on three estimates: (a) a person’s susceptibility for the rubber-hand illusion, (b) the processing demand that is required for a particular experience, and (c) the suppression/constraints imposed by the situation. We demonstrate that the impressions related to the rubber-hand illusion, and by inference the processes behind them, are comparable for different persons. This is a non-trivial finding as such invariance is required for an objective scaling of individual susceptibility and situational impediment on the basis of self-reported experiences. Regarding the validity of our vividness model, we confirm that asynchrony (e.g., Botvinick & Cohen, 1998) and information-poor stimulation (e.g., Armel & Ramachandran, 2003) constrain the development of a vivid rubber-hand illusion. Moreover, we demonstrate that the correlation between a person’s susceptibility for the rubber-hand illusion and the extent of his of her proprioceptive drift is fairly moderate, thereby confirming our conclusions from Chapter 5 regarding the limited validity of proprioceptive drift as a measure of the vividness of the rubber-hand illusion. In Chapter 7, we investigate the extent to which the large individual differences in people’s susceptibility for the illusion can be explained by body image instability, and the ability to engage in motor imagery of the hand (i.e., in mental own hand transformations). In addition, we investigate whether the vividness of the illusion is dependent on the anatomical implausibility of the fake hand’s orientation. With respect to body image instability, we corroborate a small, but significant, correlation between susceptibility and body image aberration scores: As expected, people with a more unstable body image are also more susceptible to the rubber-hand illusion (cf. Burrack & Brugger, 2005). With respect to the position and orientation of the fake hand on the table, we demonstrate that people experience a less vivid rubber-hand illusion when the fake hand is orientated in an anatomically impossible, as compared to an anatomically possible manner. This finding suggests that the attribution of foreign objects to the self is constrained by the morphological capabilities of the human body. With respect to motor imagery, our results indicate a small, but significant, correlation between susceptibility and response times to a speeded left and right hands identification task. In other words, people who are more attuned to engage in mental own hand transformations are also better equipped to develop vivid rubber-hand illusions. In Chapter 8, we examine the role of self-attribution in the experience of telepresence. For this purpose, we introduce the technological domain of mediated social touch (i.e., interpersonal touching over a distance). We anticipated that, compared to a morphologically incongruent input medium, a morphologically congruent medium would be more easily attributed to the self. As a result, we expected our participants to develop a stronger sense of telepresence when they could see their interaction partner performing the touches on a sensor-equipped mannequin as opposed to a touch screen. Our participants, as expected, reported higher levels of telepresence, and demonstrated more physiological arousal with the mannequin input medium. At the same time, our experiment revealed that these effects might not have resulted from self-attribution, and thus that other psychological mechanisms of identification might play a role in telepresence experiences. In Chapter 9, the epilogue, we discuss the main contributions and limitations of this thesis, while taking a broader perspective on the field of research on media technologies and corporeal awareness

A framework for interactivity and presence in novel bodies

Researchers are beginning to explore the consequences of interacting with virtual worlds using non-human bodies. As virtual environments become more advanced, it is possible for participants to interact with their environments in increasingly sophisticated ways. Using trackers, users can control multiple avatar limbs in order to manipulate objects, move through space, and otherwise act in the virtual world. However, these avatar bodies need not conform to the normal human configuration, either in their appearance or in the way the tracked movements of the user are rendered to control the movements of the avatar. In this chapter we use the framework developed by Haans and IJsselsteijn to investigate the experience of self-presence in cases of nonhuman avatars or avatars that otherwise differ in ability or control schema from the user’s own body; for example, avatars with more than two arms. We focus on cases where participants inhabit avatars in which the veridical mapping between tracking and rendering is disrupted

Intelligent dynamic street lighting and perceived personal safety

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Één onderzoek is géén onderzoek : het belang van replicaties voor de psychologische wetenschap

Recent criticisms on the way psychologists analyze their data, as well as cases of scientific fraud, have led both researchers and the general public to question the reliability of psychologicalresearch. At the same time, researchers have an excellent tool at their disposal to guarantee the robustness of scientific findings: replication studies. Why do researchers rarely perform replication studies? We explain why p-values for single studies fail to provideany indication of whether observed effects are real or not. Onlycumulative science, where important effects are demonstratedrepeatedly, is able to address the challenge to guarantee thereliability of psychological findings. We highlight some novelinitiatives, such as the Open Science Framework, that aim tounderline the importance of replication studies

Expected job creation across the cultural industries: a sectoral division and its implications for cultural policy

The cultural industries have come to the forefront as the potential job creators of the future. However, building on the concentric circles model and production system view of the cultural industries, we pose that many young and small organizations in the industries lack the motivation, ability, and opportunity to become job creator. We reason that industry location crucially affects job creation expectations. Evidence from an international sample of early-stage entrepreneurs strongly supports this thesis. We identify a divide between entrepreneurs in the ‘core’ cultural industries vis-à-vis those in the ‘non-core’ cultural industries, where the latter group is indistinguishable from entrepreneurs in non-cultural industries in their job creation expectations. Simultaneously, those in the core cultural industries are distinct from others in their expectations to maintain the same number of jobs, rather than grow. These findings have important implications for cultural policy aimed at promoting employment growth in the cultural industries

The Influence of Macroscopic Pedestrian Structures on Train Boarding Efficiency

A deeper understanding of pedestrian dynamics is essential to improve crowd flows in public spaces such as train stations. It is essential to understand both the physical and the psychological processes present in this context. However, current research on train boarding behavior is limited in scope and mainly focuses on how group level variables such as number of boarders/deboarders influence train boarding efficiency. Viewing pedestrian dynamics through a psychological lens is important for a detailed understanding of the train boarding context and to recognize target areas for improving crowd flows. At Dutch train stations, boarders follow a social norm of waiting at the train door until deboarding is complete. Although people generally adhere to this norm, the way it is executed may not be optimal for deboarding efficiency. We investigate how waiting boarders form a deboarding channel (a corridor where deboarders exit the train) which is a macroscopic structure formed by pedestrians, and how this channel in turn influences the efficiency of deboarding. Analyzing a dataset with 3278 boarding events at Utrecht Centraal Station in the Netherlands from 2017 - 2020 (a subset of a trajectory dataset that captures 100,000 trajectories per day), we found that higher numbers of boarders and a higher ratio of boarders to deboarders, reduced the width of the deboarding channel, and a lower width was associated with lower deboarding efficiency. These results shift the focus from group level variables to identifying macroscopic structures that are formed when pedestrians interact within a social system and provide specific target areas where nudges/behavioral interventions could be implemented