Chris North
Com 309
Professor Baird
929/97

Virtually Removing Fear
A new use for virtual reality is to treat people's phobias. Since an environment
allows the user to interact with their fear without actually experiencing it, virtual reality
provides an excellent place to provide therapy. A well designed system can allow a
psychologist to retrain a patient's response to a phobia causing item.(1)
One such phobia is the fear of flying. This is quite a prevalent fear, as "it is
estimated that 10 to 25 percent of the general population suffer from a fear of flying."(2).
At this time nearly 20 percent of the people flying feel the need to use some form of
sedative to alleviate tension while flying. This can be a major limiting factor in both
people's social and professional lives, not to mention a loss of revenue to the airline
industry.(3)
Traditionally the way to treat this phobia is to teach people how to manage of their
feelings, and then to provide them with minute amounts of exposure. This exposure could
start out as small as simply visiting an airport, with the hope that eventually the person will
be able to fly with ease.(4) To perform this therapy is quite difficult. The therapist must
set up all the visits to airplanes, potential rides, and still maintain patient confidentiality.
Doing all of this can be quite expensive, and it's efficacy has not been fully proven.(5) VR
though can be an intermediary to simply having the person imagine they on a plane and
actually thrusting the person in to the physical environment.(6)
This method can be quite advantageous to both the therapist and the patient. In the
case of the therapist, he can save hours of travel to and from an airport, the headache of
attempting to arrange for special considerations, can completely control the stimuli to the
patient, and all the maintain the patients confidentiality. On the side of the patient the
potential risks are diminished, the overall cost of the procedure is lessened, and with the
availability to have the therapy in an office. Therefore they are more likely to be willing to
undergo the therapy.(7)
The environment itself was for the fear of flying was done on a silicon graphics
machine. The VR airplane consisted of a head mounted display (HMD) with headphones.
The therapist could watch what the patient was seeing on a TV screen.(8) The development
for this system was fairly intense since "the virtual airplane required these capabilities plus
significant animation, control, and sound effect capabilities."(9) To get an effective
airplane it was necessary to have good visual model of the plane, a space for the plane to
fly through, a control system for all the different parts of an airplanes flight, and effect
sound effects.(10)
The visual model of the plane was designed in Alias's Wavefront Advanced
Visualizer software. The models were based on a Boeing 747 Cabin which airlines used to
train their personnel. The design team spend a great deal of time photographing the inside
of this cabin as it was "felt that details such as the fabric texture and color of the seats,
proper location of seat belt signs, aisle width, and window locations would be important to
providing an appropriate "look and feel" of being in a real aircraft."(11) The space for the
plane was based on different things for different parts. The ground activities like parking,
taxing, take-off and landing consisted of modeled environments with runways and
buildings. While rising in the air the ground below was texture mapped with aerial
photographs, and the clouds in the upper atmosphere were texture mapped as well. In the
end their "virtual environment contained 4,770 polygons, of which 1,919 were
textured"(12) with "11 three-component textures, which together required a minimum of
3,198,346 bytes of texture memory."(13)
The path of the plane is predetermined by the program. To place the plane, they
take the time that the plane has been in motion and calculate it's supposed speed, and find
where the plane should be in three dimensions. To keep the program portable from
machine to machine, and to ensure that all the different elements of the program remained in
synch, the entire program runs in real time. This is of particular importance for the sounds
since they are always in real time.(14)
The sounds of an airplane are quite specific, and to get them sample CDs were
used, with the files loaded onto the hard disk in AIFF format. The sounds were then edit
for length and content. The software, Simple Virtual Environment (SVE) Toolkit, allowed
for sound to be played on a remote machine, which saved computational time on the
computer. The sounds were coordinated with the visuals, and all of them were ambient,
meaning that they had no specific direction to them. Each sound was placed as it's own
recording so that depending on the situation it could be called up, or if necessary looped for
extended play. In addition, if the circumstances called for it, multiple sounds could be
played at once.(15)
A similar, although more complex, system was employed for the different phases
of the plane's travel. There are different states which the plane is in, and for each state
there are certain attributes. For example there might be engines-off state where the plane is
stationary and the engines are off, and then the engines can be turned on so that everything
is the except that the engine sound is being played. Some states will naturally flow into
another, like takeoff going into flying, but the therapist can hold the plane in certain states
so that the patient could become used to it. An example of this might be the taxing state.
To prevent the program losing it's realism certain states will not reappear until other states,
which logically follow, are performed. For instance the takeoff state will not run again
until after the landing and taxing states has been performed. (16)
To actually test the VR system a patient was found who fit the requirements of
wanting to overcome her fear of flying. They found a woman who had not flown in two
years, but for family vacations as well as job reasons felt she would like to overcome her
fears. There were a myriad of tests given which showed the level of stress she felt, and
then she used the system. The HMD was display used "two-color LCD screens that
overlap fully"(17) which each had a " horizontal field of view of 48 degrees and a vertical
field of view of 36 degrees."(18) The goggles were used in biocular with the same video
feed going to each screen. To be able to tell where the patient was looking a tracker was
placed on the HMD as well.(19)
To be able to call this treatment a success there are two major criteria: the first was if
the patient felt she was in the plane, and the second was if the treatment was effective. This
is a totally subjective measurement, but since the patient did feel some of the same anxieties
she would have she been on an airplane, then it would seem that the patient did feel as
though she were on a plane.(20)
From a treatment aspect, the VR was a success. The patient's goal was to be able
to take a trip with her family which required airplane travel. Two days after the treatment
ended she was able to take a trip with her family which involved a cross-country flight.
Although she did still feel some of the anxiety, she felt that it was an improvement.
Without the VR system this treatment would not been completed without several trips to the
airport, and possibly the therapist traveling with the patient prior to her being able to travel
with her family.(21)
So, it may be that when hardware costs drop, which will hopefully be accompanied
by an improved performance, we can have our fears alleviated in a virtual world. The
environment was fairly basic, and involved only auditory and visual cues, not motion as
some would have though, and still was able to effectively help the person overcome their
fears.

4

Bibliography

L.F. Hodges et al., "Virtual Environments for Treating the Fear of Heights," Computer,
Vol. 28, No. 7, July 1995, pp. 27-34.
Acquired at: http://dlib.computer.org:80/dynaweb/co/co1995/@Generic__ BookTextView/74902;nh=1;hf=0?DwebQuery=hodges#1

L.F. Hodges et al., "Virtually Conquering Fear of Flying," IEEE Computer Graphics
and Applications, Vol. 16, No. 6, Nov. 1996, pp. 42-49.
Acquired at: http://dlib.computer.org:80/dynaweb/cg/cg1996/@Generic__
BookTextView/69544;hf=0
on 7/28/96

Potel, Michael J. and Anne C. Lear, "Virtual Reality Provides Real Therapy," IEEE Computer Graphics and Applications Vol. 17, No. 4: July, August 1997, pp. 16- 20.
Acquired at: http://dlib.computer.org:80/dynaweb/cg/cg1997/@Generic__ BookTextView/34151;nh= 1;hf=0?DwebQuery=virtual+reality#1
on 7/26/97


Endnotes
1)Potel, Michael J. and Anne C. Lear, "Virtual Reality Provides Real Therapy," IEEE Computer Graphics and Applications Vol. 17, No. 4: July, August 1997, pp. 16- 20.
Acquired at: http://dlib.computer.org:80/dynaweb/cg/cg1997/@Generic__ BookTextView/34151;nh= 1;hf=0?DwebQuery=virtual+reality#1
on 7/26/97
2)L.F. Hodges et al., "Virtually Conquering Fear of Flying," IEEE Computer Graphics
and Applications, Vol. 16, No. 6, Nov. 1996, pp. 42-49.
Acquired at: http://dlib.computer.org:80/dynaweb/cg/cg1996/@Generic__
BookTextView/69544;hf=0
on 7/28/96
3)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
4)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
5)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
6)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
7)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
8)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
9)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
10)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
11)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
12)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
13)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
14)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
15)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
16)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
17)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
18)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
19)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
20)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996
21)L.F. Hodges et al., "Virtually Conquering Fear of Flying," 1996