First Person Experience of Body Transfer in Virtual Reality
Abstract
Background: Altering the normal association between touch and its visual correlate can result in the illusory perception of a fake limb as part of our own body. Thus, when touch is seen to be applied to a rubber hand while felt synchronously on the corresponding hidden real hand, an illusion of ownership of the rubber hand usually occurs. The illusion has also been demonstrated using visuo-motor correlation between the movements of the hidden real hand and the seen fake hand. This type of paradigm has been used with respect to the whole body generating out-of-the-body and body substitution illusions. However, such studies have only ever manipulated a single factor and although they used a form of virtual reality have not exploited the power of immersive virtual reality (IVR) to produce radical transformations in body ownership.
Principal Findings: Here we show that a first person perspective of a life-sized virtual human female body that appears to substitute the male subjects' own bodies was sufficient to generate a body transfer illusion. This was demonstrated subjectively by questionnaire and physiologically through heart-rate deceleration in response to a threat to the virtual body. This finding is in contrast to earlier experimental studies that assume visuotactile synchrony to be the critical contributory factor in ownership illusions. Our finding was possible because IVR allowed us to use a novel experimental design for this type of problem with three independent binary factors: (i) perspective position (first or third), (ii) synchronous or asynchronous mirror reflections and (iii) synchrony or asynchrony between felt and seen touch.
Conclusions: The results support the notion that bottom-up perceptual mechanisms can temporarily override top down knowledge resulting in a radical illusion of transfer of body ownership. The research also illustrates immersive virtual reality as a powerful tool in the study of body representation and experience, since it supports experimental manipulations that would otherwise be infeasible, with the technology being mature enough to represent human bodies and their motion.
Competing Interests: The authors have declared that no competing interests exist.
Funding: This research was supported by the Integrated Project PRESENCCIA funded under the European Union's Sixth Framework Program, Future and Emerging Technologies (FET), Contract Number 27731. http://cordis.europa.eu/ist/fet/pr.htm. The work was also partially supported by MS's European Research Council grant TRAVERSE (227985). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Contacts:
Mel Slater(ICREA), Universitat de Barcelona, Barcelona, Spainmelslater@gmail.com
Jen LaloupPublic Library of Sciencejlaloup@plos.org415-624-1220
Citation: Slater M, Spanlang B, Sanchez-Vives MV, Blanke O (2010) First Person Experience of Body Transfer in Virtual Reality. PLoS ONE 5(5): e10564. doi:10.1371/journal.pone.0010564
PLEASE LINK TO THE SCIENTIFIC ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (URL goes live after the embargo ends): http://dx.plos.org/10.1371/journal.pone.0010564
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IMAGE AVAILABLE AT THE FOLLOWING URL: http://www.plos.org/press/pone-05-05-slater.jpg [Figure 2 of article. Please credit Slater et al; PLoS ONE: e10564]
Evidence for Emulation in Chimpanzees in Social Settings Using the Floating Peanut Task
Abstract
Background: It is still unclear which observational learning mechanisms underlie the transmission of difficult problemsolving skills in chimpanzees. In particular, two different mechanisms have been proposed: imitation and emulation. Previous studies have largely failed to control for social factors when these mechanisms were targeted.
Methods: In an attempt to resolve the existing discrepancies, we adopted the 'floating peanut task', in which subjects need to spit water into a tube until it is sufficiently full for floating peanuts to be grasped. In a previous study only a few chimpanzees were able to invent the necessary solution (and they either did so in their first trials or never). Here we compared success levels in baseline tests with two experimental conditions that followed: 1) A full model condition to test whether social demonstrations would be effective, and 2) A social emulation control condition, in which a human experimenter poured water from a bottle into the tube, to test whether results information alone (present in both experimental conditions) would also induce successes. Crucially, we controlled for social factors in both experimental conditions. Both types of demonstrations significantly increased successful spitting, with no differences between demonstration types. We also found that younger subjects were more likely to succeed than older ones. Our analysis showed that mere order effects could not explain our results.
Conclusion: The full demonstration condition (which potentially offers additional information to observers, in the form of actions), induced no more successes than the emulation condition. Hence, emulation learning could explain the success in both conditions. This finding has broad implications for the interpretation of chimpanzee traditions, for which emulation learning may perhaps suffice.
Competing Interests: The authors have declared that no competing interests exist.
Funding: The authors have no support or funding to report.
Contacts:
Claudio TennieDepartment of Developmental and Comparative Psychology,Max Planck Institute for Evolutionary AnthropologyE-mail: tennie@eva.mpg.de
Jen LaloupPublic Library of Sciencejlaloup@plos.org415-624-1220
Citation: Tennie C, Call J, Tomasello M (2010) Evidence for Emulation in Chimpanzees in Social Settings Using the Floating Peanut Task. PLoS ONE 5(5): e10544.doi:10.1371/journal.pone.0010544
PLEASE LINK TO THE SCIENTIFIC ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (URL goes live after the embargo ends): http://dx.plos.org/10.1371/journal.pone.0010544
FOR A PRESS-ONLY PREVIEW OF THE FULL ARTICLE, VISIT THE FOLLOWING URL: http://www.plos.org/press/pone-05-05-tennie.pdf
IMAGE AVAILABLE AT THE FOLLOWING URL: http://www.plos.org/press/pone-05-05-tennie.jpg [Figure 2 of article. Please credit Tennie et al; PLoS ONE: e10544]
Fear Conditioned Discrimination of Frequency Modulated Sweeps within Species-Specific Calls of Mustached Bats
Abstract
Background: Social and echolocation vocalizations of bats contain different patterns of frequency modulations. An adult bat's ability to discriminate between various FM parameters, however, is not well established.
Principle Findings: Using changes in heart rate (HR) as a quantitative measure of associative learning, we demonstrate that mustached bats (Pteronotus parnellii) can be fear conditioned to linear frequency modulated (FM) sweeps typically centered at their acoustic fovea (,60 kHz). We also show that HR is sensitive to a change in the direction of the conditional frequency modulation keeping all other parameters constant. In addition, a change in either depth or duration co-varied with FM rate is reflected in the change in HR. Finally, HR increases linearly with FM rate incremented by 0.1 kHz/ms from a pure tone to a target rate of 1.0 kHz/ms of the conditionalstimulus. Learning is relatively rapid, occurring after a single training session.
Conclusion: We also observed that fear conditioning enhances local field potential activity within the basolateral amygdala. Neural response enhancement coinciding with rapid learning and a fine scale cortical representation of FM sweeps shown earlier make FMs prime candidates for discriminating between different call types and possibly communicating socially relevant information within species-specific sounds.
Citation: Ma J, Naumann RT, Kanwal JS (2010) Fear Conditioned Discrimination of Frequency Modulated Sweeps within Species-Specific Calls of Mustached Bats. PLoS ONE 5(5): e10579. doi:10.1371/journal.pone.0010579
Funding: Supported in part by a NIH research grants DC008822 to J.S.K. and DC01009 to R.T.N. from the National Institute for Deafness and other Communication Disorders (NIDCD). The funding agencies had no role in study design, data collection and analysis, decision to publish, or reparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist
Contacts:
Jagmeet S. KanwalDepartment of Physiology and Biophysics,Georgetown UniversityE-mail: kanwalj@georgetown.edu
Jen LaloupPublic Library of Sciencejlaloup@plos.org415-624-1220
PLEASE LINK TO THE SCIENTIFIC ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (URL goes live after the embargo ends): http://dx.plos.org/10.1371/journal.pone.0010579
FOR A PRESS-ONLY PREVIEW OF THE FULL ARTICLE, VISIT THE FOLLOWING URL: http://www.plos.org/press/pone-05-05-ma.pdf
Do Ravens Show Consolation? Responses to Distressed Others
Abstract
Background: Bystander affiliation (post-conflict affiliation from an uninvolved bystander to the conflict victim) may represent an expression of empathy in which the bystander consoles the victim to alleviate the victim's distress (''consolation''). However, alternative hypotheses for the function of bystander affiliation also exist. Determining whether ravens spontaneously offer consolation to distressed partners may not only help us to understand how animals deal with the costs of aggressive conflict, but may also play an important role in the empathy debate.
Methodology/Principal findings: This study investigates the post-conflict behavior of ravens, applying the predictive framework for the function of bystander affiliation for the first time in a non-ape species. We found weak evidence for reconciliation (post-conflict affiliation between former opponents), but strong evidence for both bystander affiliation and solicited bystander affiliation (post-conflict affiliation from the victim to a bystander). Bystanders involved in both interactions were likely to share a valuable relationship with the victim. Bystander affiliation offered to the victim was more likely to occur after intense conflicts. Renewed aggression was less likely to occur after the victim solicited affiliation from a bystander.
Conclusions/Significance: Our findings suggest that in ravens, bystanders may console victims with whom they share a valuable relationship, thus alleviating the victims' post-conflict distress. Conversely victims may affiliate with bystanders after a conflict in order to reduce the likelihood of renewed aggression. These results stress the importance of relationship quality in determining the occurrence and function of post-conflict interactions, and show that ravens may be sensitive tothe emotions of others.
Contacts:
Orlaith N. FraserDepartment of Cognitive Biology,University of Vienna, Vienna, AustriaE-mail: orlaith.fraser@univie.ac.at
Jen LaloupPublic Library of Sciencejlaloup@plos.org415-624-1220
Citation: Citation: Fraser ON, Bugnyar T (2010) Do Ravens Show Consolation? Responses to Distressed Others. PLoS ONE 5(5): e10605. doi:10.1371/journal.pone.0010605
PLEASE LINK TO THE SCIENTIFIC ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (URL goes live after the embargo ends): http://dx.plos.org/10.1371/journal.pone.0010605
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Sex Differences in Obesity Associated with Total Fertility Rate
Abstract
Background: The identification of biological and ecological factors that contribute to obesity may help in combating the spreading obesity crisis. Sex differences in obesity rates are particularly poorly understood.
Findings: Here we show that the strong female bias in obesity in many countries is associated with high total fertility rate, which is well known to be correlated with factors such as low average income, infant mortality and female education. We also document effects of reduced access to contraception and increased inequality of income among households on obesity rates. These results are consistent with studies that implicate reproduction as a risk factor for obesity in women and that suggest the effects of reproduction interact with socioeconomic and educational factors.
Conclusions: We discuss our results in the light of recent research in dietary ecology and the suggestion that insulin resistance during pregnancy is due to historic adaptation to protect the developing foetus during famine. Increased access to contraception and education in countries with high total fertility rate might have the additional benefit of reducing the rates of obesity in women.
Citation: Brooks R, Maklakov A (2010) Sex Differences in Obesity Associated with Total Fertility Rate. PLoS ONE 5(5): e10587. doi:10.1371/journal.pone.0010587
Funding: This research is unfunded, coming from a desktop analysis of publicly available data. The authors' employers (The University of New South Wales and Uppsala University) and national research councils (Australian Research Council and Swedish National Science Foundation) paid the authors' salaries. These funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Contacts:
Robert BrooksEvolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences,The University of New South Wales, SydneyE-mail: rob.brooks@unsw.edu.au
Jen LaloupPublic Library of Sciencejlaloup@plos.org415-624-1220
PLEASE LINK TO THE SCIENTIFIC ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (URL goes live after the embargo ends): http://dx.plos.org/10.1371/journal.pone.0010587
FOR A PRESS-ONLY PREVIEW OF THE FULL ARTICLE, VISIT THE FOLLOWING URL: http://www.plos.org/press/pone-05-05-brooks.pdf
Source: Public Library of Science