Packet #21
Imagine you are working on a research paper about how virtual reality
technology is changing human communication. Read the three information
sources that follow this page and keep the CAARP model in mind as you review
each source.
Remember:
C = Currency
A = Authority
A = Accuracy
R = Relevance
P = Purpose
For the third and final source you will see the address (URL) of a website. Click on
that link to be taken to a website. Please review the website as a whole for your
third and final source.
To complete your assignment, go
to: http://library.uncw.edu/instruction/UNI_library_assignment. Login at the
bottom of the page and follow the directions to answer questions about each
information source.
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Source #1
CYBERPSYCHOLOGY & BEHAVIOR
Volume 9, Number 2, 2006
© Mary Ann Liebert, Inc.
Reaching within Video-Capture Virtual Reality:
Using Virtual Reality as a Motor Control Paradigm
ASSAF Y. DVORKIN, Ph.D.1,2, MEIR SHAHAR, M.Sc., M.B.A.,2 and
PATRICE L. (TAMAR) WEISS, Ph.D.2
ABSTRACT
We have developed a virtual reality (VR) system that integrates a three-dimensional tracking
device with a video-capture VR platform to record upper limb movements. The influence of
target velocity on planning and execution of reaching movements was studied in five healthy
subjects. Our initial results suggest that a target’s velocity is considered when planning an interceptive action and that a hand reaching toward a moving virtual target is controlled in a
similar way to how it is in the real visual environment.
INTRODUCTION
T
human movements are
planned, organized, and controlled have been
of major interest to many researchers in various
fields of study. Many studies of motor control have
been carried out over the years investigating balance and posture,1 locomotion,2 and reach-to-grasp
movements.3 Arm movement studies, wherein the
hand is constrained to move within a plane (i.e.,
two-dimensional [2D] movements), have included
measurements of both simple4 and complex5,6
movements under various experimental conditions,4–6 directed at revealing the principles that underlie the planning and execution of upper
extremity motion. In comparison to the study of
planar motion, much less research has been performed on motion in three-dimensional (3D)
space.7 This is a serious limitation, since the vast
majority of functional movements are performed
within a 3D space.
In recent years, applications of virtual reality
(VR) technology have grown immensely.8 VR typically refers to the use of interactive simulations created with computer hardware and software to
HE WAYS IN WHICH
1Caesarea
present users with opportunities to engage in environments that appear and feel similar to real world
objects and events. In their search for new means to
perform motion studies, especially ones that have
greater ecological validity than traditional paradigms, researchers have begun to explore VR as a
tool to study motor control both in healthy subjects
and patients suffering from motor deficits.1,8,9–12
In such studies, subjects and patients interact
with virtual objects instead of real physical objects.
Holden et al.9 developed a virtual environment
training system based on the principle of learning
by imitation, which allows the user to retrain a
wide variety of arm movements within the context
of goal-directed tasks (e.g., place an envelope in a
slot). While previous studies demonstrated significant differences in reaching performance in the real
versus a virtual environment,12 other studies
showed that both adults with motor deficits and
healthy individuals used similar movement strategies in both environments.8 Finally, Martin et al.11
explored the effect of immersion on the online visuomotor control of arm movement. The authors
showed that hand-reaching toward a virtual target
was controlled in a similar way to that which oc-
Rothschild Institute, University of Haifa, Haifa, Israel.
of Occupational Therapy, University of Haifa, Haifa, Israel.
2Department
133
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DVORKIN ET AL.
curred in the real visual environment, suggesting
that online control processes of goal-directed
movement are preserved in VR (provided that the
environment remains stable).
The use of VR technology can provide a powerful
and flexible method for motion studies, particularly
in the case of reach-to-grasp experiments.10 In contrast to positioning real objects prior to each trial,
the VR presentation allows for efficient data collection. It enables easy relocation of an object in space
and alterations to the object’s characteristics (e.g., its
size and shape). The experimental scenarios may be
customized to specific investigations and to simulate real-life environments that would be difficult to
create with real-world set-ups. This capability is especially important for clinical studies, in order to
enable a patient to practice performance in a safe
and ecologically valid environment.13,14 Finally, VRbased motion studies may be standardized such
that experiments may be performed in different locations under the same conditions.10
The goal of the current study was to validate VR
as a paradigm for studying reaching kinematics in
healthy subjects. A further aim of this study was to
examine the influence of target objects’ velocity on
planning and execution of reaching movements.
METHODS
Five young healthy adults (mean age = 30.1
years; SD = 3.9) consented to participate in the
study. All subjects were right-handed, and had normal or corrected-to-normal vision, and were not
color blind. The VividGroup’s Gesture Xtreme (GX)
video-capture VR system (<www.gesturetek.com>)
was used. This system has been adapted for use in
rehabilitation.13 It consists of a 34-inch screen, Pentium IV desktop computer, and a single digital
video camera that converts the visual signals of the
subject’s movements for processing. The user does
not have to wear or support extraneous devices in
order to achieve a substantial intensity of immersion within the virtual environment.13 The subject
sits in a demarcated area viewing a mirror image of
himself on the 2D screen that displays a simulated
functional task, based on the “Birds & Balls” scenario of the GX VR system.15
A six-degree-of-freedom magnetic tracker (“Polhemus fastrak,” <www.polhemus.com/fastrak.
htm>) was integrated and synchronized with the
GX VR system and used to measure arm movements. The sampled coordinates from a single
tracking sensor, attached to the right hand, was
sampled at 120 Hz; the hand trajectory and velocity
were reconstructed off-line.
The subjects first performed a 3–7-min practice
session to become familiar with the required task.
The experiment consisted of five blocks of 40 trials
each, with a rest period of about 2–5 min between
the blocks, and lasted for a total of 30 min. Each target condition was presented 10 times, randomly ordered within the blocks, for a total of 200 trials. The
subject was seated on a wooden chair, located at a
fixed distance (1.5 m) from the GX VR monitor, and
performed reaching movements with the right
hand. Straps restrained the subject’s trunk movements. The subject wore a red cloth glove, with the
tracking sensor attached to it. The “red glove” option of the GX VR was used to restrict system response to only one body part (i.e., the right hand).
A wooden stand, located on the right side of the
subject’s body, adjusted to knee level, served as the
initial position of the responding hand. Four different spatial target positions were defined in terms of
the subject’s arm length and shoulder position.
Thereafter, target positions were arranged within
the virtual scene, symmetrically around the subject’s right shoulder, at 70°, 30°, 30°, and 70°,
with respect to the raised hand.
At the beginning of each trial, the hand was located at the initial start position. After a random
time interval of 1.3–2 sec, a virtual visual target (a
red ball) appeared in one of the four predefined locations. As soon as the target appeared on the
screen, it moved in a straight line toward the starting position of the responding hand, at a constant
velocity. Five different velocity values were used in
the experiment (2.0, 7.0, 12.0, 17.0, and 22.0
cm/sec). The subject was instructed to reach as fast
as possible as soon as the red target appeared on
the screen. A trial was terminated when either the
subject touched the target or when the target
reached the virtual initial start position.
The spatial characteristics of the movement were
recorded from the tracking sensor, and the speed of
the hand movement was calculated. Data were filtered off-line with a fourth-order Butterworth lowpass filter (8-Hz cut-off frequency). A 4% tangential
peak velocity threshold was used to determine the
onset and offset of the hand movements. The spatial and temporal variables—including hand path
curvature index, movement time (MT), reaction
time (RT) to initiate a movement, and peak tangential velocity—were measured and analyzed. The
curvature index was calculated as the ratio of the
actual 3D length of the path to the length of the
straight line joining the initial and final endpoint
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USING VR AS A MOTOR CONTROL PARADIGM
positions. Thus, for an ideal straight line, the index
is 1.3 Descriptive statistics were tabulated, and a
two-way analysis of variance (ANOVA; target position target velocity) was carried out on mean values of the variables.
RESULTS
Figure 1A shows the 3D hand paths of a representative subject for one of the target configurations.
Subjects were able to reach toward and hit the moving target without irregularities of the reach. However, the spatial hand paths were consistently
curved, in accordance with previous studies that investigated 3D and vertical hand movements compared to horizontal planar movements.16 The
velocity profiles were single-peaked and bellshaped, in accordance with observations in realworld environments. An example of a representative
tangential velocity profile is shown in Figure 1B.
There was no main effect for target spatial position, for all measures. In contrast, an effect of target
velocity was found; as velocity increased, MT significantly decreased (F(4,115) = 47.4; p < 0.0001). Furthermore, the path curvature index increased (F(4,95)
= 2.4; p = 0.055) and the time to peak velocity decreased (F(4,115) = 2.45; p = 0.05). However, both peak
hand velocity and RT remained unaffected by velocity, although we did see a trend for RT, where a
non-significant decrease was found for increasing
values of the target velocity.
CONCLUSION
The main purpose of this study was to investigate, using a video-capture VR system, the influ-
135
ence of target velocity on reaching movements. A
detailed kinematic analysis of the movements
showed that target velocity significantly affected
MT, path curvature index, and time to peak velocity. Based on previous studies, we hypothesized
that RT would decrease and peak hand velocity
would increase with increasing values of the target
velocity. However, no significant change was
found for either measure. Results from the current
study suggest that hand reaching toward a moving
virtual target was programmed and controlled in a
similar way to that of the real visual environment,
thus, indicating that control of goal-directed movements is preserved in the virtual environment.
Whereas our preliminary results necessitate further investigation on a larger population, they
are in line with previous studies, which examined
the effect of target motion in real world environments.17
In summary, these initial results demonstrate
that applications of VR video-capture technology
to motion studies research provide a novel approach for investigating motor control mechanisms
and can further help to provide answers for questions that are relevant to rehabilitation. This system
allows us to explore more complex behaviors,
which are necessary especially for rehabilitation.
Furthermore, patients with neurological impairment such as stroke may benefit from use of this
type of technology for retraining motor or cognitive deficits. The basic paradigm used in this study
could be enhanced to take advantage of the welldocumented VR assets such as increased motivation, stimulus control, immediate feedback and
quantitative documentation of results.14 For example, the stimuli may be placed in locations that require patients to reach with greater range of motion
or the cognitive complexity of the stimuli may be
enlarged thereby increasing the attentional de-
A
B
80
Velocity [mm/ms]
3.5
Z axis [cm]
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Initial position
0
-20
-70
X axi
0
s [cm
]
-30 -60
Y axis [cm]
700
0
Time [ms]
FIG. 1. Examples of three-dimensional hand paths for one of the target configurations (A) and a tangential velocity
profile (B), for a representative subject.
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DVORKIN ET AL.
mands of the task. Such applications will be targeted for future studies.
ACKNOWLEDGMENTS
9.
10.
We thank Uri Feintuch and Rani Bar-On for their
assistance.
11.
REFERENCES
1. Keshner, E.A. (2004). Head-trunk coordination in elderly subjects during linear anterior-posterior translations. Exp. Brain Res. 158:213–222.
2. Yano, H., Kasai, K., Saitou, H., et al. (2003). Development of a gait rehabilitation system using a locomotion interface. Journal of Visualization and Computer
Animation 14:243–252.
3. Archambault, P., Pigeon, P., Feldman, A.G., et al.
(1999). Recruitment and sequencing of different degrees of freedom during pointing movements involving the trunk in healthy and hemiparetic
subjects. Exp. Brain Res. 126:55–67.
4. Messier, J., & Kalaska, J.F. (1999). Comparison of
variability of initial kinematics and endpoints of
reaching movements. Exp. Brain Res. 125:139–152.
5. Dvorkin, A.Y. (2004). Space representation using
multiple reference frames in the motor system [Doctoral dissertation]. Jerusalem: Hebrew University of
Jerusalem.
6. Henis, E.A., & Flash, T. (1995). Mechanisms underlying the generation of averaged modified trajectories.
Biol. Cybern. 72:407–419.
7. Karnath, H-O, Dick, H., & Konczak, J. (1997). Kinematics of goal-directed arm movements in neglect:
control of hand in space. Neuropsychologia 35:435–
444.
8. Viau, A., Feldman, A.G., McFadyen, B.J., et al. (2004).
Reaching in reality and virtual reality: a comparison
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17.
of movement kinematics in healthy subjects and in
adults with hemiparesis. J. NeuroEng. Rehab. 1:11.
Holden, M.K., & Dyar, T. (2002). Virtual environment
training: a new tool for neurorehabilitation. Neurol
Rep. 26:62–71.
Kuhlen, T., Kraiss, K.F., & Steffan, R. (2000). How
VR-based reach-to-grasp experiments can help to
understand movement organization within the
human brain. Presence: Teleoperators and Virtual Environments 9:350–359.
Martin, O., Julian, B., Boissieux, L., et al. (2003). Evaluating online control of goal-directed arm movement
while standing in virtual visual environment. J. Visual. Comput. Animat. 14:253–260.
Lott, A., Bisson, E., Lajoie, Y., et al. (2003). The effect of
two types of virtual reality on voluntary center of
pressure displacement. CyberPsychol. Behav. 6:477–485.
Kizony, R., Katz, N., & Weiss, P.L. (2003). Adapting
an immersive virtual reality system for rehabilitation. J. Visualization Comput. Animation 14:261–268.
Rizzo, A.A., & Kim, G.J. (2005). A SWOT analysis of
the field of VR rehabilitation and therapy. Presence:
Teleoperators and Virtual Environments 14:119–146.
Weiss, P.L., Rand, D., Katz, N., et al. (2004). Video
capture virtual reality as a flexible and effective rehabilitation tool. J. NeuroEng. Rehab. 1:12.
Desmurget, M., & Prablanc, C. (1997). Postural control of three-dimensional prehension movements. J.
Neurophysiol. 77:452–464.
Mason, A.H., & Carnahan, H. (1999). Target viewing
time and velocity effects on prehension. Exp. Brain
Res. 127:83–94.
Address reprint requests to:
Prof. Patrice L. (Tamar) Weiss
Department of Occupational Therapy
University of Haifa
Mount Carmel, Haifa
31905, Israel
E-mail: tamar@research.haifa.ac.il
Source #2
1 of 1 DOCUMENT
The Guardian (London) - Final Edition
Source #2
August 3, 2014 Sunday
The New Review: Discover: If you could only see the world through my eyes: Virtual reality has come of age at last, with
Facebook and Google vying to buy up headset manufacturers and uses ranging from treating children with ADHD to
helping reduce post traumatic stress. Time to try it out, says Kadhim Shubber
BYLINE: Kadhim Shubber
SECTION: OBSERVER REVIEW DISCOVERY; Pg. 22
LENGTH: 1846 words
My body is in the Observer's offices in King's Cross, but my mind is in another world entirely.
Strapped to my head is the Google Cardboard virtual reality headset. Assembled from a handful of simple components, the cardboard contraption has whisked me away into a peaceful forest
with red, orange and brown trees.
I am completely alone, except for an grey animated rat chasing after a large orange hat. I turn my head to watch as a gust of wind blows the hat and can't help but stumble after the rodent, arms
outstretched like a toddler taking its first steps.
I look away and as I gaze upwards, the Samsung S4 smartphone in the headset detects my motion and the field of view moves with me. The forest canopy is captivating. When I return to the rat,
he is where I left him - the storyline effectively paused when my attention was elsewhere. Eventually, the rat and his hat are reunited and I'm suddenly back in the real world. I am intensely
aware that the bridge of my nose is being assaulted by the hard edges of the headset.
Windy Day is just one of the apps for Google Cardboard, together with Google Street View and Google Earth, but is certainly its most charming. Google's do-it-yourself virtual reality (VR)
headset is designed to give the public a taste of the immersive possibilities of the virtual world for around £50 - if you have access to an Android smartphone and can find some cheap glass
lenses.
But it's merely the crest of a growing wave of excitement about virtual reality, most famously led by Oculus VR, the company behind the Oculus Rift headset. Purchased this year by Facebook
for $2bn, the Kickstarter that catapulted the company into fame in 2012 was one of the largest crowdfunding projects ever, raising around $2.4m. This is virtual reality's moment in the limelight;
it's now time for the technology to deliver.
The early 90s saw a similar amount of excitement about the possibilities of VR, with visionaries such as computer scientist Jaron Lanier predicting a future where we worked and played in
virtual reality environments online.
It soon became apparent that the technology wasn't ready. Virtual reality was a nice idea, but little more than that.
This time around it's different, says Professor Albert "Skip" Rizzo, director of medical virtual reality at the University of Southern California's Institute for Creative Technologies.
"It's 1994 all over again. It's the same thing. But this time it's real," he tells me.
Rizzo leads a team looking at the use of virtual reality environments in everything from classrooms for children with attention deficit disorder to exposure therapy for war veterans suffering
from post-traumatic stress disorder.
Advances in graphics, computing power and interface devices such as the Nintendo Wii or Microsoft Kinect have opened the door to a new level of sophistication of virtual reality, he says. Most
important, though, has been the continuing drop in cost of virtual reality technology, a trend largely driven by the gaming industry.
"Right now, a headset is $2,000. . . if you could replace that with a $350 headset (such as the Oculus Rift) and have that be better then you're golden - that's the direction we're heading," says
Rizzo, whose lab the Oculus Rift's inventor, Palmer Luckey, worked in before launching the headset.
Accompanying the improvement in off-the-shelf commercial technology has been a boom in military interest in virtual reality. Put simply, without the wars in Afghanistan and Iraq, virtual
reality wouldn't be where it is today.
"The urgency of war required novel solutions," says Rizzo, noting that tens of millions of dollars of US military funding has "fed the scientists in my lab over the last few years". The reason for
that funding is simple: virtual reality offers a means of rehabilitating war veterans effectively yet cheaply.
One method being pioneered by Rizzo involves taking a veteran through a traumatic incident by immersing them in a recreation of that incident in a virtual world. Clinical trials of the method are
still continuing, but "so far all the data has been promising and positive", he says.
Just as virtual reality is being used to help soldiers reintegrate into society after returning from war, it is also being used to train them for fighting in the first place.
The Defence Science and Technology Laboratory at the Ministry of Defence is investigating how virtual reality technology can be used to give the British army an edge in the field. Andrew
Poulter leads the research and says that virtual reality training has a number of advantages over traditional training in the field.
Take, for example, training soldiers driving in a convoy how to respond to an ambush or an improvised explosive device (IED) attack, as troops in Afghanistan have experienced. Recreating
that experience in the field repeatedly requires a significant amount of time and resources. "In a simulation, you can reset back to the beginning and go straight away again," says Poulter. Indeed,
research published in 2008, looking at US, Canadian and British forces, showed that soldiers appear to be better prepared for combat when they have been trained in a virtual reality
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environment as well as in the field. But Poulter is somewhat downbeat about the advantage immersive headsets have over simple desktop monitors, keyboards and mouses. "There's very little
done with headsets," says Poulter, for the simple reason that a headset can also prevent the soldiers from performing simple tasks such as taking notes or operating a radio.
In truth, VR headset technology still has several failings.
The display resolution of virtual reality headsets is still far behind what can be achieved with digital monitors. Nausea is another issue; users of the Oculus Rift, including the CEO, Brendan
Iribe, have reported feeling sick after using the headset, an issue the company says it's working to fix in future versions of the device. One sceptic of headset technology is Professor Robert
Stone from the University of Birmingham, who has worked on virtual reality projects with everyone from local heritage sites to hospitals to the Ministry of Defence.
"I've been doing this for 27 years and we always get the question - what is the killer application for virtual reality? - and, to be honest, at the moment there isn't one, because the technology is
letting the side down a bit," he says.
For him, new headset technology is still held back by the same limitations that scuppered VR in the 90s and the alternative, namely large HD monitors, is a much better means for involving a
person in a task or game. Furthermore, he says, VR headsets can be actively harmful to the goal of treating patients, distancing the patient from their doctor or nurse. He is also sceptical of
Rizzo's work using the technology to treat PTSD sufferers
In the gaming industry, you find little of Stone's pessimism about virtual reality headsets. The Oculus Rift should go on sale in 2015, Sony is developing its own headset, the Morpheus, and
several other companies are trying to get in on the game.
Developers are taking note. In 2013, UK-based company nDreams began working almost exclusively on games designed to be played with virtual reality headsets, including an adventure game
called The Assembly for Oculus Rift and Sony Morpheus.
nDreams CEO, Patrick O'Luanaigh, is optimistic about the future of headset technology, describing the terrifyingly real experience of playing space horror game Alien Isolation on the Oculus
Rift at June's E3 games conference in Los Angeles.
"When the alien came for me, I ripped the headset off in fear because it is so scary," he says. "That's the sort of reaction I certainly have never had before with a video game." The only
comparable shift in experience, says O'Luanaigh, was the move from 2D to 3D gaming. He estimates that by Christmas 2015, virtual reality headsets will have finally hit the mainstream
consumer market in a significant way. And once people start using them, they'll realise why the experience is "so special".
After only an hour with Google's Cardboard headset, a low-budget and limited virtual reality experience, it's hard to disagree.
HOW VR IS CHANGING THE WORLD:
1) Flight simulators are perhaps the most recognisable form of virtual reality training, but the British army has a simulator for what happens when you jump out of a plane too. The parachute
jumping simulator suspends soldiers from a parachute-like harness while they wear a VR headset that takes them through the entire experience of making a jump. It also allows them to learn
what to do if something goes wrong. It's just one of a range of virtual reality training applications in the UK military, many of which are similar to ordinary video gaming.
2) Surgery is an area that could see a lot of benefit from virtual reality technology. Studies have long shown that surgeons who practise an operation in virtual reality perform better when they
enter the operating theatre. It's a simple case of practice makes perfect. But VR has a role to play during surgery too. In a recent operation in Spain, a patient under local anaesthetic wore an
Oculus Rift headset in order to whisk her away from the operating theatre and the stress of the procedure. To top it off, her surgeon was wearing a Google Glass headset, streaming the procedure
live to students.
3) When patients are recovering from an operation, virtual reality still has a part to play. One trial currently underway at the Queen Elizabeth hospital in Birmingham involves placing large HD
monitors by the bedsides of recovering patients in intensive care. The monitors are intended to be windows on to virtual simulations of the peaceful Devon countryside. It has long been known
that patients with pleasant views recover faster than those without and it is hoped that allowing patients to also explore an environment will help boost this effect.
4) The most hyped area for virtual reality today is in gaming. Developers are combining technologies to create a full-body experience. Headsets let a player feel like they are seeing through the
eyes of their character, while force-feedback gloves and even vests let them feel what their character feels. Combine that with omni-directional treadmills that also allow you to jump - they are
similar to jumping seats for babies - and the dream of playing a video game almost literally as the character is slowly coming true. KS
Captions:
HOW TO MAKE YOUR OWN CARDBOARD GOOGLE VISOR
Slot in the eyepiece then fold the cardboard around it. This is perhaps the trickiest part.
Cutting the cardboard is the first challenge. Best to get it laser cut. We used Laser Make in north London.
Fold the eyepiece so that the lenses sit snugly between the two notched outer holes.
Apply some glue to the side flap so that the headset holds together.
BOXING CLEVER Kadhim Shubber models the Google Cardboard headset. Photographs by Katherine Rose
The NFC sticker will launch the 'cardboard' VR experience once your phone is in place.
Finally, slot your Android smartphone into place and you're ready to roll!
LOAD-DATE: August 3, 2014
LANGUAGE: ENGLISH
PUBLICATION-TYPE: Newspaper
Copyright 2014 Guardian Newspapers Limited
All Rights Reserved
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Source #3
Click on the link below. Examine the website and answer
the questions for “Source 3.”
http://www.eurovr-association.org/