Interacting in a Virtual Environment, the role of visual perception, the human hand and the recognition of rescaling.
Dublin Core
Title
Interacting in a Virtual Environment, the role of visual perception, the human hand and the recognition of rescaling.
Creator
Connor Yates
Date
2018
Description
A common assumption from perception research is that we can estimate the size of the environment by using our own hand as a perceptual metric by comparing the size of our hand to the environment. Further research aimed to explore this effect by manipulating the size of the hand to see if it could accurately estimate the size of objects and found that even when the hand was magnified or minimized people perceived their hand to stay around the same size. The effect that the hand is perceived as a constant size is called the hand-size constancy effect and the current research has aimed to expand on previous research by examining if hand-size constancy still occurs even when hand size increases whilst in the presence of the participant. This research was done using a new method which eliminates more demand characteristics than previous hand-size constancy research. Participants took part in a virtual scenario using virtual reality in which each time a participant attempted the task, their hand or non-corporeal hand gradually increased in size, until a total of 38% size increase. Results from this research found that participants did recognise their hand size increase in the non-corporeal condition and did not notice hand size change in the real hand condition. These results support previous research by finding that hand size constancy can still occur even when eliminating demand characteristics that may have occurred in previous research using a more discrete method.
Subject
Visual Perception
Rescaling effects
Virtual Reality
Hand-size Constancy
Body size effects.
Rescaling effects
Virtual Reality
Hand-size Constancy
Body size effects.
Source
Participants.
The participants were 30 typically developing adults between the ages of 19 and 50 (N = 30, 12 male and 18 female, M = 24.39 years old, SD = 7.76 years). Participants were mainly recruited from a major university in the North West of England using posters on the university campus and online advertisements. Participants received £5 in return for their participation.
Materials
The current research used the Oculus Rift with leap motion to detect hand movement. The experiment was created using the Unity game engine software to create a programme called the virtual bowling alley. The virtual bowling alley was created to mimic a real table top bowling alley in which all the items in the game were created for this experiment including the bowling ball, the pins and the virtual hand used in the experiment.
Two questionnaires were essential to this study, “The Embodiment Questionnaire” and “The Virtual Presence Questionnaire”. The Embodiment questionnaire was an adaptation from Sanchez-Vives’ research which explored visual hand illusions (Sanchez-Vives, Spanlang, Frisoli, Bergamasco, & Slater, 2010). The embodiment questionnaire was used to test the extent of different variables the participant may exhibit whilst within virtual reality. Variables related to ownership of limbs in virtual reality e.g. “I sometimes felt as if my hand was located where my virtual hand was to be” the illusion of movement which looked at how much your virtual arm impacted on the movement of your real arm, validity which looked at how your movements impacted on your virtual arm and control regarding how much control you had of your virtual arm. The Embodiment Questionnaire uses a 7-point Likert scale in which you rate how much you agree with the statement (Appendix 1). The other questionnaire required for this study was “The Virtual Presence Questionnaire” which was an adapted version from Usoh’s paper looking at presence questionnaires (Usho, Catena, Arman, & Slater, 2000). The virtual presence questionnaire was used to examine how much the participant rated their immersion within the virtual scenario. Rating of virtual immersion was done through questions which examined whether their sense of immersion whilst being within the virtual scenario was stronger than their sense of place in their actual location within the virtual reality lab. For example, questions like “To what extent were there times the virtual bowling scenario was reality for you” was used to examine immersion and presence within virtual reality. The virtual presence questionnaire also used a 7-point Likert scale (1 = disagree, 7 = agree) (Appendix 2).
Other materials required were a calculator to count the amount of bowling pins knocked down each attempt and to total the amount of bowling pins knocked down per participant. All the appropriate ethical documentation was also required (Information sheet, Virtual Reality health and safety sheet, consent document and debriefing sheet).
Procedure
After the 30 participants required for the study were obtained, the participants were asked to sign a digital calendar in which they selected which day they were free to take part in the study with the promise of a 30-minute experiment and £5 reward for taking part. Participants were advised to arrive to the lab 10 minutes prior to the study and when they did arrive they were greeted by the researcher at the door of the lab. After a short introduction, the participant was then sat down at a table with some documents and writing equipment.
The participant was asked to look at the study information sheet first, this sheet contained contextual knowledge about the study regarding the task that they would get involved in. After the participant stated that they understood all the information on the information sheet then they were given the ethics consent form to sign. The ethics consent form contained all the participants ethical rights (right to withdraw, anonymisation of the data etc…), the participants were advised to carefully read through the sheet to make sure they understood their ethic rights and asked to sign their name, age and date on the ethic sheet. Also, on a separate piece of paper, the researcher noted the participants participant number which was used to code the data anonymously. When the participant completed the ethics consent form, they were told that the experiment would now begin.
The participant was escorted to a different desk with a computer set up on the desk. Noticeably, the computer was set up in a way in which the chair was at a set distance from the oculus rift sensor to allow for full immersion. The participant was sat down on the chair that was at the set distance away from the computer, in which the computer was set to the home screen and the researcher assisted the participant in putting on the oculus rift head mounted display (HMD), the HMD had a hand sensor attached to the front of it to detect hand movement. When the participant was sat down, they were asked to confirm that they were comfortable with the HMD on and that they could see clearly. When the participant gave consent, they were told that they were going to enter the virtual bowling alley now, the virtual bowling alley was an in-house created virtual scene used for this experiment. The virtual bowling alley was created in the unity engine using C++ to create virtual objects such as the pins and ensuring they had an interaction engine script attached to them to give them physics. The virtual bowling alley was a table top bowling simulation, created with the intention that there would be a lot of hand exposure during the experiment as the participants would have to use their hands to push the ball and knock over the pins
Participants were assigned to 1 of 2 groups; the hand group or the non-corporeal hand group. The group the participant was assigned to impacted on what type of hands they would have during the virtual bowling scenario, for example, when entering the virtual bowling alley in the hand group your hands would be regular virtual hands that are created to mimic real hands. (Figure 2). Participants who were assigned to group 2 (the non-corporeal hand group) when entering the virtual bowling alley, they would see blocks in place of their hands, these block hands were created to replace their hands in virtual reality with objects that could complete the same tasks that a hand could, but did not represent the hand in any way, a non-corporeal hand.
When participants entered the virtual bowling scenario and confirmed that they were calibrated to the bowling scenario (their visual view point was correct, and they could move their hands around accurately) then they were told they had 20 attempts to knock down as many pins as they could, with 10 pins an attempt this means there was a total of 200 pins. Each time an attempt was completed by the participant, the experiment would press a key on the keyboard which reset the pins and the bowling ball for the participant. Each time the virtual bowling alley attempt was reset the participants hand (group 1) or cubes (group 2) increased in size by approximately 2% per bowling task attempt until they completed their 20 attempts in which their hand/ non-corporeal hand would have increased in size by 38%. Also, it is worth mentioning that each time the bowling ball attempt was completed, and the alley was reset the bowling ball would randomly change from bigger to smaller sizes (10 different sizes per experiment between 50% increase in size and 50% decrease in size, twice per size). The changes in the ball size were required so that participants did not use the bowling ball as a reference of scale to compare to their change of size in hands or cube hands (non-corporeal hands).
When the participant completed the 20 attempts of the bowling task, the virtual bowling programme would automatically exit, and the participant was asked to take off the HMD and escorted back to their first seat which was the table they completed their consent form. The experimenter also made note on a separate sheet of the participants total bowling pins knocked down out of 200. When the participant was sat down at the table the experimenter would then hand the participant a sheet with 2 questions on it. Question 1: “Did you detect any changes whilst in the virtual environment?” this is a yes or no response. After the participant answered question 1 they were then asked question 2 “If hand size was manipulated would you estimate your hand changed in size or not?”. The response for question 2 would also be a yes or no response, it is worth noting that if the participant did respond with “yes” to question 2, then the researcher asked them if they estimated if hand size increased or decreased in which the experimenter would ask the participant to note this response underneath question 2. After they answered the 2 questions regarding the virtual bowling alley the participant would then be handed 2 more documents both being questionnaires. The participant would be asked to firstly fill out the virtual presence questionnaire and then the virtual embodiment questionnaires, they were also told if they had any questions regarding the questionnaires they could ask at any time. After the participant confirmed that they were happy with their responses to the questions and completed all the questions then the experimenter passed the participant a debrief sheet which gave more context to the experiment and was very explicit about the participants hand changing in size over time. The participant was asked if they had any questions regarding the experiment, if they did the researcher happily answered them, if not, then the researcher would thank the participant for their time.
When all the results were collected from the 30 participants, the data was stored on a locked private computer in which only the experimenters had access to. All documents regarding the experiment were also locked in a storage cabinet which was under lock and key. The independent variable in this study was hand type (hands vs non-corporal hands) and the dependent variable in this study was the response to the questions regarding the virtual bowling scenario (question 1 and 2). Due to the nature of the dependent variables data a Chi-Square was used as nominal data was collected on 2 independent groups. Other data regarding age, gender, handedness, virtual presence scores and virtual embodiment scores were also analysed using independent t-tests.
The participants were 30 typically developing adults between the ages of 19 and 50 (N = 30, 12 male and 18 female, M = 24.39 years old, SD = 7.76 years). Participants were mainly recruited from a major university in the North West of England using posters on the university campus and online advertisements. Participants received £5 in return for their participation.
Materials
The current research used the Oculus Rift with leap motion to detect hand movement. The experiment was created using the Unity game engine software to create a programme called the virtual bowling alley. The virtual bowling alley was created to mimic a real table top bowling alley in which all the items in the game were created for this experiment including the bowling ball, the pins and the virtual hand used in the experiment.
Two questionnaires were essential to this study, “The Embodiment Questionnaire” and “The Virtual Presence Questionnaire”. The Embodiment questionnaire was an adaptation from Sanchez-Vives’ research which explored visual hand illusions (Sanchez-Vives, Spanlang, Frisoli, Bergamasco, & Slater, 2010). The embodiment questionnaire was used to test the extent of different variables the participant may exhibit whilst within virtual reality. Variables related to ownership of limbs in virtual reality e.g. “I sometimes felt as if my hand was located where my virtual hand was to be” the illusion of movement which looked at how much your virtual arm impacted on the movement of your real arm, validity which looked at how your movements impacted on your virtual arm and control regarding how much control you had of your virtual arm. The Embodiment Questionnaire uses a 7-point Likert scale in which you rate how much you agree with the statement (Appendix 1). The other questionnaire required for this study was “The Virtual Presence Questionnaire” which was an adapted version from Usoh’s paper looking at presence questionnaires (Usho, Catena, Arman, & Slater, 2000). The virtual presence questionnaire was used to examine how much the participant rated their immersion within the virtual scenario. Rating of virtual immersion was done through questions which examined whether their sense of immersion whilst being within the virtual scenario was stronger than their sense of place in their actual location within the virtual reality lab. For example, questions like “To what extent were there times the virtual bowling scenario was reality for you” was used to examine immersion and presence within virtual reality. The virtual presence questionnaire also used a 7-point Likert scale (1 = disagree, 7 = agree) (Appendix 2).
Other materials required were a calculator to count the amount of bowling pins knocked down each attempt and to total the amount of bowling pins knocked down per participant. All the appropriate ethical documentation was also required (Information sheet, Virtual Reality health and safety sheet, consent document and debriefing sheet).
Procedure
After the 30 participants required for the study were obtained, the participants were asked to sign a digital calendar in which they selected which day they were free to take part in the study with the promise of a 30-minute experiment and £5 reward for taking part. Participants were advised to arrive to the lab 10 minutes prior to the study and when they did arrive they were greeted by the researcher at the door of the lab. After a short introduction, the participant was then sat down at a table with some documents and writing equipment.
The participant was asked to look at the study information sheet first, this sheet contained contextual knowledge about the study regarding the task that they would get involved in. After the participant stated that they understood all the information on the information sheet then they were given the ethics consent form to sign. The ethics consent form contained all the participants ethical rights (right to withdraw, anonymisation of the data etc…), the participants were advised to carefully read through the sheet to make sure they understood their ethic rights and asked to sign their name, age and date on the ethic sheet. Also, on a separate piece of paper, the researcher noted the participants participant number which was used to code the data anonymously. When the participant completed the ethics consent form, they were told that the experiment would now begin.
The participant was escorted to a different desk with a computer set up on the desk. Noticeably, the computer was set up in a way in which the chair was at a set distance from the oculus rift sensor to allow for full immersion. The participant was sat down on the chair that was at the set distance away from the computer, in which the computer was set to the home screen and the researcher assisted the participant in putting on the oculus rift head mounted display (HMD), the HMD had a hand sensor attached to the front of it to detect hand movement. When the participant was sat down, they were asked to confirm that they were comfortable with the HMD on and that they could see clearly. When the participant gave consent, they were told that they were going to enter the virtual bowling alley now, the virtual bowling alley was an in-house created virtual scene used for this experiment. The virtual bowling alley was created in the unity engine using C++ to create virtual objects such as the pins and ensuring they had an interaction engine script attached to them to give them physics. The virtual bowling alley was a table top bowling simulation, created with the intention that there would be a lot of hand exposure during the experiment as the participants would have to use their hands to push the ball and knock over the pins
Participants were assigned to 1 of 2 groups; the hand group or the non-corporeal hand group. The group the participant was assigned to impacted on what type of hands they would have during the virtual bowling scenario, for example, when entering the virtual bowling alley in the hand group your hands would be regular virtual hands that are created to mimic real hands. (Figure 2). Participants who were assigned to group 2 (the non-corporeal hand group) when entering the virtual bowling alley, they would see blocks in place of their hands, these block hands were created to replace their hands in virtual reality with objects that could complete the same tasks that a hand could, but did not represent the hand in any way, a non-corporeal hand.
When participants entered the virtual bowling scenario and confirmed that they were calibrated to the bowling scenario (their visual view point was correct, and they could move their hands around accurately) then they were told they had 20 attempts to knock down as many pins as they could, with 10 pins an attempt this means there was a total of 200 pins. Each time an attempt was completed by the participant, the experiment would press a key on the keyboard which reset the pins and the bowling ball for the participant. Each time the virtual bowling alley attempt was reset the participants hand (group 1) or cubes (group 2) increased in size by approximately 2% per bowling task attempt until they completed their 20 attempts in which their hand/ non-corporeal hand would have increased in size by 38%. Also, it is worth mentioning that each time the bowling ball attempt was completed, and the alley was reset the bowling ball would randomly change from bigger to smaller sizes (10 different sizes per experiment between 50% increase in size and 50% decrease in size, twice per size). The changes in the ball size were required so that participants did not use the bowling ball as a reference of scale to compare to their change of size in hands or cube hands (non-corporeal hands).
When the participant completed the 20 attempts of the bowling task, the virtual bowling programme would automatically exit, and the participant was asked to take off the HMD and escorted back to their first seat which was the table they completed their consent form. The experimenter also made note on a separate sheet of the participants total bowling pins knocked down out of 200. When the participant was sat down at the table the experimenter would then hand the participant a sheet with 2 questions on it. Question 1: “Did you detect any changes whilst in the virtual environment?” this is a yes or no response. After the participant answered question 1 they were then asked question 2 “If hand size was manipulated would you estimate your hand changed in size or not?”. The response for question 2 would also be a yes or no response, it is worth noting that if the participant did respond with “yes” to question 2, then the researcher asked them if they estimated if hand size increased or decreased in which the experimenter would ask the participant to note this response underneath question 2. After they answered the 2 questions regarding the virtual bowling alley the participant would then be handed 2 more documents both being questionnaires. The participant would be asked to firstly fill out the virtual presence questionnaire and then the virtual embodiment questionnaires, they were also told if they had any questions regarding the questionnaires they could ask at any time. After the participant confirmed that they were happy with their responses to the questions and completed all the questions then the experimenter passed the participant a debrief sheet which gave more context to the experiment and was very explicit about the participants hand changing in size over time. The participant was asked if they had any questions regarding the experiment, if they did the researcher happily answered them, if not, then the researcher would thank the participant for their time.
When all the results were collected from the 30 participants, the data was stored on a locked private computer in which only the experimenters had access to. All documents regarding the experiment were also locked in a storage cabinet which was under lock and key. The independent variable in this study was hand type (hands vs non-corporal hands) and the dependent variable in this study was the response to the questions regarding the virtual bowling scenario (question 1 and 2). Due to the nature of the dependent variables data a Chi-Square was used as nominal data was collected on 2 independent groups. Other data regarding age, gender, handedness, virtual presence scores and virtual embodiment scores were also analysed using independent t-tests.
Publisher
Lancaster University
Format
data/SPSS.sav
data/csv
data/csv
Identifier
Yates2018
Contributor
Ellie Ball
Rights
Open
Relation
None
Language
English
Type
Data
Coverage
LA1 4YF
LUSTRE
Supervisor
Dr Sally Linkenauger
Project Level
MSc
Topic
Cognitive, Perception Psychology
Sample Size
30 Participants (12 male and 18 female)
Statistical Analysis Type
Chi-squared
t-test
t-test
Files
Collection
Citation
Connor Yates, “Interacting in a Virtual Environment, the role of visual perception, the human hand and the recognition of rescaling.,” LUSTRE, accessed April 26, 2024, https://www.johnntowse.com/LUSTRE/items/show/82.