72 8 Fisher LSD post-hoc comparisons of the comfort distances between the three levels of embodiment. 9 Fisher LSD post-hoc comparisons of the reaction times between the three levels of embodiment for Experiment 1.
Contributions
In addition, we will provide further understanding of how interpersonal space is correlated with the modulation of peripersonal space in immersive virtual environments. We ultimately find that the peripersonal space can now be delineated, thus opening a door to a further understanding of this interaction space in immersive virtual environments.
Significance
We also find that this methodology is a reliable measure of peripersonal space boundaries in immersive virtual environments. Findings from both of these papers lay the groundwork for a greater understanding of interpersonal and peripersonal space in immersive virtual environments.
Overview
Physiological Evidence for the Division of Space
These neurons respond especially to stimuli close to the body within the peripersonal space [di Pellegrino and Ladavas 2015; Gentilucci et al. Of even further interest is a recent study on the encoding of perpersonal space in relation to other individuals.
Behavioral Evidence for the Division of Space, Including Virtual Reality Evidence
2016] investigated similarities between peripersonal space and interpersonal distance across age and gender. Additional work has shown that peripersonal space is influenced by temporal information [Iachini et al.
Embodiment, Presence and Interaction
Embodiment and Presence in Immersive Virtual Environments
For example, some studies find a greater physiological response to threats when users of immersive environments are given a first-person rather than a third-person perspective [Petkova et al. This illusion has been replicated in an immersive virtual environment [Yuan and Steed 2010] and further research suggests that ownership of an entire virtual body can be experienced [Normand et al.
Social Presence in Immersive Virtual Environments
This work mostly finds that face-to-face communication facilitates a higher level of social presence during interaction [Alge et al. Studies find that social presence increases when visual representation is present [Feng et al.
Interaction in Immersive Virtual Environments
One method for assessing non-social interactions in immersive virtual environments is that of object manipulation. Social interaction in immersive virtual environments has often been considered in the context of collision avoidance.
Affordances
- An Introduction to Affordance Theory
- Joint Affordance and Action
- Operationalization of Affordances and Joint Affordances
- Affordances in Immersive Virtual Environments
- Pilot Study
- Participants
- Materials and Methods
- Results and Analysis
- Discussion
This concept has been applied in the fidelity study of IVEs (Geuss et al. All of our participants agreed on passability in this ratio when making judgments based on their and their partner's dimensions of opening width and combined shoulder width .
Experiment 2: Affordance Judgments in an Immersive Virtual Environment
- Participants
- Materials and Methods
- Results and Analysis
- Comparing Experiment 1 and 2
Since female-female pairings did not exhibit behavior that was out of the ordinary in the first experiment, we chose not to include a female-female pairing with male-female avatars in this experiment. Thus, we cannot confirm the second hypothesis and must note that the underlying gender of the participants did not make a difference in the way the participants behaved. To test the third hypothesis—the critical conditions found in the virtual environment would be smaller than the critical conditions found in the real world—we need to compare the results of Experiments 1 and 2.
We compared similar pairs in the real and virtual worlds where participant gender and avatar gender were matched (ie, male–male participants with male–male avatars).
Discussion and Conclusions
Our final hypothesis was that the critical threshold in the virtual environment would be lower than that in the real world. Presumably, as the fidelity of virtual avatars increases, critical thresholds in a virtual environment will converge to those found in the real world. These studies investigated whether the boundaries of peripersonal space in an immersive virtual environment are consistent with those in the real world and whether they can be altered by object and agent interactions.
We also tried to study the modulation of peripersonal space in the presence of different types of virtual objects that evoked differently.
Experiment 1: Peripersonal Space Boundaries Modulated by Objects
- Power and Experimental Participants
- Apparatus
- Experimental Design
- Object Likeability Ratings
- Results
- Discussion
It is well known in the neuroscientific and psychological literature that the peripersonal space is modulated according to the social context of the situation [Iachini et al. First, we find out how the individual reaction times were affected by the research conditions, and then we determine the boundaries of the peripersonal space for the (group) research conditions. The xcre parameter represents the middle of the area of maximum increase in reaction time to a visual stimulus, i.e. the border of the peripersonal space.
Comparing the social and nonsocial conditions yields a Jeffrey-Zellner-Siow (JZS) Bayes factor of 8.11, indicating substantial evidence in favor of the null hypothesis.
Experiment 2: Peripersonal space Boundaries Modulated by Agents
- Participants
- Apparatus
- Experimental Design
- Agent Likeability Ratings
- Results
- Discussion
These distances were chosen due to the size of the agents, but still keeping in mind the limits of natural perpersonal space. Once outliers were removed, we averaged all reaction times for each trial at each distance for each mean. The "average" agent group consisted of the average female and male group, and the "intimidating" agent group consisted of the intimidating females and males.
It is worth mentioning that it can be assumed that the perpersonal space boundary can be modulated by the size of the agents since they are significantly larger than the balls used in the first experiment.
General Discussion
Limitations and Future Work
It would be interesting to see how the dimensions of the self-avatar affect the modulation of the peripersonal space and thus the interaction, since the dimensions of the self-avatars affect the possibilities of acting in virtual environments [Lin et al. Determining how self-localization affects the perception of action capabilities and the modulation of peripersonal space in multi-user environments seems fruitful according to recent work [van der Veer et al. It would also be interesting to see if and how the boundaries of the peripersonal space change with embodiment and the factors that influence it [Gonzalez-Franco and Peck 2018].
And finally, it would be interesting to determine the required level of co-presence to evoke naturalistic modulation of peripersonal space considering the findings of Podkosova and Kaufmann [2018a] showing co-located users to modulate a level of peripersonal space while users of distributed no.
Conclusions
In this chapter, we want to understand how different characteristics of self-avatars affect the boundaries of interpersonal and peripersonal space. Two experiments were used using visual and tactile stimuli to determine the boundaries of interpersonal and peripersonal space. Q1: Does the level of embodiment experienced by the user affect users' interpersonal and peripersonal space in an immersive virtual environment.
Q2: Do avatar physical characteristics, such as arm length, affect users' interpersonal and peripersonal space in an immersive virtual environment.
Experiment 1: Personal Space Boundaries and Embodiment
- Power and Experimental Participants
- Apparatus
- Experimental Design
- Results
- Discussion
The agent and avatar used in the low and medium embodiments (pictured in Figure 15) were taken from Adobe Mixamo, and the avatars used in the high embodiment (see also Figure 15), which were gender and race matched, were all made using Adobe Fuse (which has since been discontinued). Until now, the peripersonal space boundaries of the participants have not been determined. Finally, comparing the low and medium conditions yields a JZS Bayes factor of 5.26 in favor of the null hypothesis.
Any of the other factors, such as the omission of delay and delay combined with the first-person perspective, could be key to the increased level of embodiment in the high embodiment condition.
Experiment 2: Personal Space Boundaries and Arm Manipulation
- Power and Experimental Participants
- Apparatus
- Experimental Design
- Results
- Discussion
To determine whether peripersonal space boundaries changed based on the manipulation of hand dimensions in this experiment, we performed an RM-ANOVA with condition as a factor. Thus, we can see that there are great possibilities in favor of keeping the boundaries of the users' peripersonal space the same, even if the hand dimensions of one's own avatar are manipulated. This suggests further results, which we will discuss in the next paragraph, implying that the hand dimension manipulation did not affect the boundaries of peripersonal space.
Finally, a really interesting result from this experiment is the fact that the peripersonal space boundaries did not change based on the manipulation of the arm dimensions.
General Discussion
Limitations and Future Work
In any case, our findings regarding H3 support previous literature indicating that virtual reality users adapt the way they interact with the space around them to the given dimensions of their self-avatar [Jun et al., 2015]. For example, people suffering from different psychological disorders handle personal space differently [Alcorn et al., 2011; Iachini et al., 2015b; Lee et al., 2021], and personality type shapes personal space [Iachini et al., 2015b]. Previous work has produced mixed results regarding how people interact with their interpersonal space in these scenarios, with some users being cautious toward others [Buck et al., 2019] and others casually colliding with other users' avatars [ Podkosova and Kaufmann, 2018a ].
It would also be interesting to understand how different levels of sensuality or interactions with human-led avatars and computer-led agents affect personal space, as we know that eye contact increases sensuality and changes the way users communicate interpersonal space [Bailenson et al. , 2003].
Conclusions
The results from our second experiment on peripersonal space are also incredibly important in the neuroscience community, where there has been debate about the connection between peripersonal space and arm's length space [Zanini et al., In Press]. There are several modalities for measuring personal space around the body (ie, comfort distance, reach, and peripersonal space). This space has not been comprehensively measured in immersive technology, but it provides a reliable metric for the space around the body, which is not subjective [Serino et al., 2017] and is associated with interpersonal spaces [Coello and Cartaud, 2021].
Finally, in Chapter 5, we extended our knowledge of personal space in immersive virtual environments by measuring both interpersonal and peripersonal space in the context of different self-representations.
Future Work
Finally, it would be interesting to understand how the personal space changes in virtual reality with respect to the user's mental state. InProceedings of the 18th ACM Symposium on Virtual Reality Software and Technology, VRST ’12, pages 129-136, New York, NY, USA. Body space in social interactions: a comparison of reach and comfort distance in immersive virtual reality.
Cortical mechanism of tool use subject to multisensory integration. The Handbook of Multisensory Processes, pages 453-462. The effect of agency and anthropomorphism on users' sense of telepresence, co-presence, and social presence in virtual environments. InProceedings of the ACM Symposium on Virtual Reality Software and Technology, VRST ’02, pages 171-178, New York, NY, USA.
