Chapter 5. Arachnophobia and fear of other insects
Efficacy and lessons learned from studies on treatment process
1. Key variables involved in animal phobia.
The pathological fear of animals, spiders, bugs, mice, cats or snakes, among others, can
be severe enough to be considered a specific phobia according to the DSM-IV and the ICD-10
classifications (APA, 2000; WHO, 1992). It falls under the animal subtype in both classifications.
Using data from the Epidemiological Catchment Area Survey, Bourdon, Boyd, Rae and Burns
(1988) revealed that the lifetime prevalence of specific phobias of spiders, bugs mice and snakes
is about 7% among women and 2% among men. Using more reliable estimates from the National
Comorbidity Survey, Curtis, Magee, Eaton, Wittchen and Kessler (1998) found a lifetime
prevalence rate of animal phobia of 5.7%, and the lifetime of non-pathological fears of animals to
be around 25.8%. Fredrickson, Annas, Fisher and Wik (1996) reported the point prevalence rate
(actual rates of prevalence at the time of assessment) of specific phobias to be 5.5% for snake
phobia and 3.5% for spider phobia. More recently, a large epidemiological study conducted in the
United States reported a prevalence rate of 4.7 % for animal subtype specific phobia in the
general population (Stinson et al., 2007). Since the large majority of studies using virtual reality
have been conducted on the specific phobia of spiders, the theoretical context of this chapter will
focus mostly on arachnophobia. However, VR studies on animal phobia in general will be
People suffering from arachnophobia show marked, persistent and excessive anxiety upon
actual or anticipated exposure to spiders and avoid spiders and situations in which they might
encounter a spider. Animal phobias normally begin in childhood and affect twice as many
women as men, although men may underreport their fears (Frederickson et al., 1996; Curtis et al.,
1998; Öst, 1987).
Because fear of spiders is so prevalent and easy to induce, arachnophobia has been
studied extensively in experimental research. This led to important findings for our understanding
of the nature and treatment of phobias. These findings raise issues that are important to virtual
reality applications as well. Let’s take disgust, for example. Research on anxiety disorders, and
on phobias in general, has typically focused on perceived danger or perceived threat. In 1986,
Watts suggested that disgust was probably involved in arachnophobia. Indeed, disgust is now
more and more recognized as an important element in some specific phobias such as fear of bugs,
snakes or spiders (McNally, 2002). For example, Woody, McLean and Klassen (2005) used the
intensity of disgust and anxiety to predict avoidance during a series of behavior avoidance tasks
with a tarantula in a cage and a pen that had been touched (contaminated) in the cage by the
tarantula. Among their 115 participants, the intensity of disgust was a significant and stronger
predictor of avoidance than level of anxiety, both for avoidance of the tarantula and the
contaminated pen. In addition, twice as many participants avoided the contaminated pen among
the highly fearful participants compared to the less fearful participants. These results are in line
with findings from Mulkens, de Jong and Merckelbach (1996) where only 25% of their phobic
participants agreed to eat a cookie that a spider had walked across, compared to 71% of their non-
phobic participants. These experimental studies illustrate how arachnophobic avoidance is related
to disgust and not only perceived threat. Smiths, Telch and Randall (2002) also showed that
changes in disgust and fear are partially independent from each other, while Edwards and
Salkovskis (2006) further revealed that fear magnifies the reaction of disgust but that disgust does
not enhance fear. All these findings highlight for VR designers the importance of stimuli that
elicit fear and disgust in the development of virtual environments. They also alert therapists to
which cues they must draw a patient’s attention to during exposure therapy and the relationship
between these cues.
Given that specific phobia is the simplest of the anxiety disorders in terms of fear and
avoidance, researchers have also used fear of spiders to study neurological correlates of phobias
and their treatment. Studies have shown that fear is an alarm reaction that involves specific neural
areas of the brain such as the limbic system, the prefrontal cortex, and the hippocampus (Philips,
Drevets, Rauch & Lane, 2003). For example, using an fMRI with participants suffering from
spider phobia, Larson et al. (2006) found a strong but brief reaction of the amygdala, suggesting
that this area of the brain may be more involved in the rapid detection of threat and initial
processing of fear than in the sustained processing of threat. Other studies conducted with spider
phobics using fMRI have shown that exposure-based therapy leads to significant change in brain
functioning (Paquette et al., 2003; Straube, Glauer, Dilger, Mentzel & Miltner, 2006). For
example, Schienle, Schäfer, Stark and Vaitl (2009) investigated the long-term effects of exposure-
based CBT on brain activation in spider phobics using fMRI technology. Ten patients underwent
an fMRI session 6 months after successfully completing CBT to treat spider phobia. Patients
were exposed to phobic relevant pictures while brain activation was being monitored. Results
from the fMRI at 6 month follow-up showed an increased activation in the medial orbitofrontal
cortex, a region of the brain involved in the representation of positive reinforcers, and a decreased
activation in the lateral orbitofrontal cortex, an area implicated in the processing of negative
stimulations. These results illustrate how exposure-based treatments can allow learning new
associations with the lack of threat. Patients learned to perceive the phobic relevant stimulus as
rewarding, probably because their interaction with the spider during therapy led to positive affect
and a sense of accomplishment. In that same fashion, they learned that there were no negative
consequences associated with their interaction with the spider.
Addressing the neurophysiology of fears is important because it could help therapists
understand that the treatment mechanism of exposure involves changing: (a) the automatic
association between spider and threat/disgust (an operation involving the amygdala, among other
brain areas), (b) mental representations of these associations that have been learned and are stored
in the memory (an operation involving the hippocampus, among other areas), and the
contribution of reflexive processes (an operation involving the pre-frontal cortex, among other
Studying spider phobia has also helped scientists understand the treatment mechanism
behind exposure. To quote Powers, Smits, Leyro and Otto (2006), “as compared to early
conceptualizations of extinction as the systematic unlearning of a learned association, modern
learning theory now conceptualizes extinction as the acquisition of new learning” (p. 109; see
also Bouton, 2007 and Abramowitz, 2013 for a detailed review on learning and Powers et al.
2006 and Abramowitz, Deacon and Whiteside, 2011 for clinical applications). The psychological
mechanism behind exposure is therefore conceptualized as the active development and learning
of safe associations with the feared stimuli rather than as a passive weakening, or unlearning, of
previous associations with threat (and probably disgust, although this is much less studied).
According to Bouton (2007), both the learned associations developed during the acquisition of
the fear and the learned associations developed during therapy remain after extinction. Thus, an
additional strategy to increase the generalization of new learning outside of the therapist’s office
is to vary the contexts in which the patient is exposed to the feared stimuli. Otherwise, facing
feared stimuli in a new context can cause a patient to rely on previously learned dysfunctional
associations, rather than on the more functional ones learned in therapy, and therefore relapse.
The study by Mineka, Mystkowski, Hladek and Rodriguez (1999) conducted with spider phobics
provides a nice example of the importance of context on the generalization of treatment gains.
They treated 36 arachnophobics with in vivo exposure in either one of two therapy contexts that
differed based on: therapist’s gender and clothing, room size, salient visual cues in the two
rooms, room location, and size and color of the exposure tools such as the terrarium for the
tarantula. Participants were retested with a behavior avoidance test one week post-therapy either
in the same context in which they received their therapy or in the other context. Participants
tested in the novel context showed significantly more anxiety during the test compared to those
retested in the same context where they received their therapy. This finding has been replicated
using slightly different methodologies (Mystkowski, Craske & Echiverri, 2002; Mystkowski,
Mineka, Vernon and Zinbarg, 2003; Vansteenwegen, Vervliet, Hermans, Thewissen & Eelen,
2007)). Mystkowski, Craske, Echiverri and Labus (2006) even showed that mentally reinstating
the therapy context (remembering what happened and what was learned) before being tested in
the novel setting is beneficial for the patients. To support the idea that exposure will be most
effective when the therapy maximizes the salience of threat disconfirmation, Wolitsky, Rellini
and Telch (2005) showed that height phobics benefited more from therapy when they adopted
anti-phobic or paradoxical behaviors such as running toward the balcony of a high place or
leaning over the edge of a balcony without holding the railing. Even if this study was not
conducted with spider phobics, the conclusion remains: one key mechanism behind exposure is to
develop new associations with safety (or, at least, with non-threat). This also raises a potential
advantage of VR, which is helping arachnophobic patients perform anti-phobic behavior that is
difficult or impossible to do otherwise, such as holding a tarantula, facing dozens of spiders at the
same time, or encountering exaggeratedly large spiders. Mineka and Thomas (1999) also
highlighted that simply changing the direct associations with threat and safety is incomplete.
They argued for the importance of developing new mental representations that one can cope by
increasing perceived self-efficacy. Increased perceived self-efficacy is an important factor in
anxiety (Bandura, 1986) and may contribute to explaining the generalization effect.
Using evidence-based knowledge about the treatment mechanism for specific phobia is
essential in the development of virtual environments and in conducting any form of exposure,
including in virtuo exposure (Abramowitz, 2013; Bouchard et al., 2012; Otto & Hofmann, 2010).
For example, based on the information presented in the paragraphs above, it would be important
for generalization to vary the characteristics of the virtual spiders, along with the virtual locations
where the patients are exposed to virtual spiders. Virtual locations depicting situations where
patients would usually encounter a spider, such as a kitchen, bedroom, patio, or backyard with a
picnic table, should lead to better generalization than less common virtual locations such as a
cavern or a virtual room with no furniture. To maximize learning new associations with safety
and high self-efficacy, distraction should not interfere with cognitive and emotional processing.
Research on the effect of distraction on exposure have been inconsistent, with most studies
showing that distraction reduces treatment efficacy and some reporting no detrimental effects.
These apparently contradictory findings are in fact all pointing in one direction: the distraction
should not interfere with the learning of adaptive safety associations with the stimuli and with
regards to self-efficacy (Powers et al., 2006; Richards, Lauterbach & Gloster, 2006; Telch, 2004).
Hence, engaging in stimulus-relevant or stimulus-irrelevant conversations while maintaining
visual attention to a spider during exposure will not hinder the efficacy of exposure (Johnstone &
Page, 2004), but focusing visually on a stimulus irrelevant to spiders will be detrimental
(Mohlman & Zinbarg, 2000).
2. Description of significant efficacy studies using non-VR approaches.
Early treatment of arachnophobia included imaginal flooding and implosion (Marshall,
Gauthier, Christie, Currie, & Gordon, 1977) or systematic desensitization (Rachman,
1966). With empirical data showing that the key ingredient in those forms of therapy
was the systematic exposure to the feared stimuli, clinicians progressively shifted their
efforts towards exposure itself. Regrettably, no large-scale randomized control trial for
spider phobia has yet been conducted using a passive (i.e., waiting list) or non-specific
(i.e., placebo) control condition. Based on the assumption that results of controlled
studies documenting the efficacy of in vivo exposure with other forms of phobia (see
Öst, 1997 for an overview of controlled studies) can be extended to arachnophobia,
several outcome studies used active treatments or different forms of exposure as control
conditions. For example, Hellström and Öst (1995) used four different controls to test
against the efficacy of a three-hour in vivo exposure session conducted with a therapist:
(a) a treatment manual specifically targeting arachnophobia, to be used at home; (b) a
treatment manual specifically targeting arachnophobia, to be used at the clinic, (c) a
treatment manual non-specific to arachnophobia, to be used at home; and (d) a treatment
manual non-specific to arachnophobia, to be used at the clinic. Note that for all four
control conditions, the treatment was delivered without the assistance of a therapist and
participants had to plan for two 2-hour therapy sessions on their own. Their 52
participants were assessed with behavioral, physiological and self-report measures at
pretreatment, post-treatment and one-year follow-up. At the follow-up, the success rate
of in vivo exposure therapy reached 80%, compared to 63% for the specific manual
applied at the clinic, 10% for the general manual applied at the clinic, 10% for the
specific manual applied at home and 9% for the general manual applied at home. Nine
of the 10 participants in the one-session of in vivo exposure were able to reach the
maximum score on the behavioral avoidance test (BAT; i.e, holding a spider in their
hands for 20 seconds). Öst, Salkovskis and Hellstrom (1991) reported that a three-hour
session of in vivo exposure with a therapist helped 71% of participants suffering from
spider phobia reach a clinically significant improvement, compared to 6% of
participants performing self-directed exposure at home over weeks. Other studies have
supported the efficacy of one session of intense in vivo exposure (e.g., Götestam, 2002),
or that exposure delivered in a group is an effective alternative to individual exposure
(Öst, Ferebee & Furmark, 1997). It is important to note that the one-session exposure
treatments used guided mastery, which is a slightly more intensive form of exposure. In
this case, the therapist first conducts an individualized case conceptualization in a
session preceding exposure. The exposure itself is used like a series of behavioral tests,
conducted to weaken dysfunctional beliefs, as opposed to simple exposure. The therapist
also models approach behaviors. This approach enables the therapist to try moving faster
along the hierarchy within the three-hour session, with the explicit rationale that
exposure must be continued at home after the session (Öst, 1997).
One research group from the University of Tasmania in Australia used a computer
program to conduct vicarious exposure (Smith, Kirby, Montgomery & Daniels, 1997;
Gilroy, Kirby, Daniels, Menzies & Montgomery, 2000). Their computer-aided vicarious
exposure software (see Figure 1) allows the patient to help a character on a computer
screen face the feared stimuli1. In one controlled study, Gilroy et al. (2000) randomly
1 This form of computer-assisted exposure is not described in the section on in virtuo exposure because: (a) the
authors themselves do not claim that their treatment is a form of VR, (b) the depth of the real-time interactivity is
limited, (c) the user consciously remains in the physical office of the therapist, controlling the actions of someone
else in the synthetic environment, (d) the immersion properties of the system are significantly weaker than what is
found in VR, (e) the acronym CAVE refers here to “computer-aided vicarious exposure” and not to the C-Automated
assigned 45 spider phobics to either computer-aided vicarious exposure, therapist-
delivered in vivo exposure or relaxation placebo. They found that both active treatments
were effective and superior to placebo on all measures at post-treatment and at follow-
up. Live graded exposure was superior to computer-aided vicarious exposure only on the
behavior avoidance test at post-treatment. All other post-treatment comparisons were
non-significant and, at follow-up, all comparisons including the BAT were non-
significant. A 33-month follow-up supported the lack of difference between both forms
of exposure (Gilroy, Kirby, Daniels, Menzies & Montgomery, 2003). However, results
on the BAT were rather low at post-treatment and follow-up, with participants
completing on average only half of the avoidance/approach task (i.e., partially opening a
container with a live spider). It raises some doubts about the overall efficacy of the
treatments. Another study from the same group (Heading, Kirkby, Martin, Daniels,
Gilroy & Menzies, 2001) revealed less promising results, with the computer-assisted
vicarious exposure being significantly less effective than in vivo and not significantly
different from the waiting list. A study with 28 children aged 10 to 17 also suggested
that in vivo exposure was more effective than the use of their computer software (Dewis
et al., 2001). Nevertheless, this line of research addressed vicarious exposure, an option
that is used less systematically by therapists but that could be beneficial for highly
Insert Figure 1 here (two screenshots University of Tasmania)
3. Description of the studies using virtual reality approaches to treat arachnophobia.
The first study published on the use of in virtuo exposure to treat the specific phobia of
spiders is from Carlin, Hoffman and Weghorst (1997). They provided 12 weekly sessions of a
treatment consisting essentially of in virtuo exposure and deep muscle relaxation to a 37-year old
woman who had been severely arachnophobic for 20 years. The in virtuo exposure consisted of
five 5-minute immersions, with breaks between each immersion, during therapy sessions lasting
about 50 minutes each. The length of the immersion was kept brief in the hope of reducing
cybersickness. Two virtual spiders were used. After four therapy sessions, tactile cues were added
by having the patient touch a furry toy spider with her physical hand while she would see her
virtual hand touching the virtual spider (i.e., tactile augmentation; see Figure 2). The therapy led
to a decrease in subjective anxiety within and between exposure sessions, a reduction in scores on
a self-report instrument and reports of a reduction of dysfunctional behaviors. A one-year follow-
up indicated that treatment gains were still intact (Hoffman, 1998).
Insert Figure 2 here (Hoffman and Spider World)
To further study the impact of tactile augmentation, Hoffman, Garcia-Palacios, Carlin,
Furness III and Botella (2003) conducted a study with a pooled sample of eight arachnophobics
and 28 fearful, yet non-phobic university students. The diagnosis of specific phobia was made
according to DSM-IV criteria and the fear of the non-phobics had to reach one standard deviation
above the mean of their classmates on the Fear of Spiders Questionnaire (Szymanski &
O’Donohue, 1995) to qualify for the study. They randomly assigned the phobic and the non-
phobic participants to either no treatment, in virtuo exposure without tactile augmentation or in
virtuo exposure with tactile augmentation. The treatment consisted of three 1-hour therapy
sessions delivered over one week. The VR environment was the same as Carlin et al. (1997) and,
except for the computer, the hardware was the same as well, with a dVisor HMD from
Division™, a Polhemus motion tracker (for the head, the hand, and the toy spider), and a Silicon
Graphics computer. Results on a modified version of the Fear of Spider Questionnaire revealed
that both forms of treatment led to improvements that are significantly superior to the no-
treatment condition but not significantly different from one another (see Figure 3). A different
pattern of results was found on the level of anxiety felt during the behavior avoidance test, with
VR plus tactile augmentation being significantly more effective than VR without tactile
augmentation, the latter not being significantly different from the no-treatment controls. For the
distance on the BAT, both treatments were found to be effective when compared to the control
condition, with the tactile augmentation group performing significantly better (on average,
getting as close as 6 inches to a live tarantula in a closed terrarium) than the VR without tactile
augmentation (on average, getting as close as 2.5 feet to a live tarantula in a closed terrarium).
Given the small number of clinically phobic participants (three in each treatment group) and the
divergences between the three outcome measures, it is difficult to draw confident conclusions
about the usefulness of the tactile augmentation. Nevertheless, the Hoffman et al. (2003)
hypothesis that adding tactile feedback may lead to stronger emotional processing for spider
phobics seems sound. In light of the literature on the importance of disgust and the advantage of
varying contexts to foster generalization, tactile augmentation may be very useful clinically to
help patients touch or kill spiders.
Insert Figure 3 here (results from Hoffman et al. (2003)
In a more controlled study, Garcia-Palacios, Hoffman, Carlin, Furness III and Botella
(2002) assigned 23 adults who were clinically phobic of spiders according to DSM-IV criteria to
a wait-list control condition or an in virtuo exposure treatment. The therapy was flexible in length
(from 3 to 10 sessions, for an average of four 1-hour sessions) and consisted essentially of
exposure while immersed in VR. The first therapy sessions were conducted without tactile
augmentation. After patients were able to face a virtual spider drifting from a vase to the floor,
tactile augmentation was introduced. Patients were encouraged to touch the virtual spider with
their virtual hand, while at the same time their physical hand was actually touching the furry toy
spider. The hardware and software were the same as in Hoffman et al. (2003), except for a
different HMD (V8 from Virtual Research™). Results showed significant differences from pre to
post-therapy for the treatment group only on measures such as a BAT, level of anxiety felt during
the BAT, clinician’s ratings of severity and the Fear of Spider Questionnaire (see Figure 4). At pre
treatment, people who received in virtuo exposure were on average only able to approach to
within three meters from a closed terrarium containing a large tarantula, while at post-treatment
they were able to touch the closed terrarium with their hands.
Insert Figure 4 here (results from Garcia-Palacios et al. (2002)
Given the high cost of the VR hardware and software used by Hoffman and his team,
Bouchard, Côté, St-Jacques, Robillard and Renaud (2006) developed a VR environment using the
3D-game Half-Life™. Actually they did not use the game itself, which is a violent first-person
shooter game, but the game engine. A game engine is the core software component that allows
developing and running a computer or a video game. Some powerful game engines are available
for free, either on the web or on the CD-ROM of the game itself. It is therefore possible to
modify the game to some extent (this is legal as long as the modified product is not used for
profit2). They developed a VR environment with five rooms containing spiders that were
progressively more frightening in terms of number, size and behaviors (see Figure 5 for
screenshots). Because of restrictions imposed by the technology and resources available at the
time, the researchers had to use graphic material and computer programs already available within
the game (e.g, color of the walls, behavior of the spiders). The software cost about $50 in 2000,
and the virtual environments took about two weeks of programming. To test this beta version of
the VR environment, 11 spider phobics received four weekly therapy sessions of 90 minutes in
which they followed a written treatment manual. The first therapy session included presentation
of psychoeducational material about arachnophobia and its treatment plus a first VR immersion
in an environment devoid of spiders. The following three sessions included in virtuo exposure
only, except for the last 20 minutes of the final session, where relapse prevention was addressed.
The hardware used was also more affordable than in previous studies. It included a Pentium III
computer, an I-Glass HMD from IO-Display™, an Intertrax2 from Intersense™ and a joystick.
Results of this uncontrolled study were promising, as all measures significantly decreased from
pre to post-treatment. However, clinical observations showed the necessity to improve the
software significantly (e.g., use a more natural environment than a concrete basement with a
military look, improve the virtual spiders by refining their appearance, making them look more
realistic and diversifying their behavior, etc.).
Insert Figure 5 here (screenshots of the first VR environment developed at UQO using
2 See the End-User License Agreement of each software program for details.
The largest randomized control trial for arachnophobia so far was conducted by
Michaliszyn, Marchand, Bouchard, Martel and Poirier-Bisson (2010) using a second VR software
program developed at Université du Québec en Outaouais (UQO) with the 3D-game engine Max
Payne™ (see Figure 6). Thirty-two spider phobics were recruited and assigned to eight 90-minute
sessions of in vivo or in virtuo exposure. Half of the sample had previously been assigned to a
waiting list before receiving their treatment. The researchers used the same treatment manual as
the Bouchard et al. (2006) study initiated five years earlier, but the hardware was newer and
slightly more powerful than before. Two live house spiders were used for in vivo exposure.
Results showed significant improvements from pre to post treatment, with no difference between
the two treatment groups and stability of the results over the 3-month follow-up. The scores of
both conditions at the BAT show that on average participants in each condition were able to touch
a terrarium containing a live tarantula and put their hands into it (see Figure 7). The authors noted
that three participants did not experience any fear in the virtual environment and one felt
significant cybersickness, which is precious information usually omitted in outcome studies on
Insert Figure 6 (screenshots of the second VR environment developed at UQO using 3D
game engine) and Figure 7 (results on the BAT from Michaliszyn et al.) here.
In order to document the impact of in virtuo exposure on psychophysiological and
information processing measures and to explore the treatment process of in virtuo exposure, Côté
and Bouchard (2005) studied 28 adults suffering from spider phobia according to the DSM-IV
(APA, 2000). Their hypotheses were that: (a) treatment would have an impact not only on self-
report and behavioral measures, but also on physiological and information processing indices,
and (b) the treatment mechanism of in virtuo exposure would involve change in dysfunctional
beliefs, self-efficacy and information processing. Their intention was not to conduct an efficacy
study but rather to confirm that change did occur in order to find out what would predict
outcome. The treatment and the hardware were similar to Bouchard et al. (2006), except for the
addition of one session of in virtuo exposure to the treatment manual, the use of a more powerful
computer and a slightly better HMD. The researchers used the software developed at UQO based
on the experience previously learned during the pilot study with Half-Life™ (Bouchard et al.,
2006), a program that was also used by Michaliszyn et al. (2010) with a few additional therapy
sessions. In addition to questionnaires like the Fear of Spider Questionnaire (Szymanski &
O’Donoghue, 1995), patients completed measures of dysfunctional beliefs towards spiders and of
perceived self-efficacy to confront various situations involving spiders. They also performed a
behavior avoidance test while their heart-rate variability was measured. Finally, the participants
completed a non-lexical emotional Stroop task where pictures of spiders (threat stimuli), cows
(neutral-control stimuli) and rabbits (positive-control stimuli) were presented on a computer
monitor covered by a colored filter. Participants had to push a button corresponding to the color
of the screen as fast as they could when they saw the pictures (see Figure 8). The pictorial Stroop
task engages cognitive resources in two competitive processes, i.e. perceiving the color and
perceiving the feared stimuli. The interference created by images of spiders, compared to images
of rabbits and cows, expresses the activation of an emotional processing specific to spiders. At
post treatment, changes on all variables were statistically significant, with patients able to remain
seated less than 50 centimeters away from a live tarantula in an open terrarium. The originality of
the analyses presented in this paper show that in virtuo exposure led to significant changes in
cardiac response during the BAT as well as in the emotional processing of the feared stimuli.
Slight symptoms of virtual reality induced side effects (cybersickness) were observed during the
immersions but they decreased significantly over the course of treatment. The feeling of presence
was high and only minor changes in this measure were reported over time.
In a second paper dedicated to the analysis of treatment mechanism, Côté and Bouchard
(2009) used residualized change scores to find the best predictors of improvement on the Fear of
Spider Questionnaire (i.e., a general measure of outcome), on the performance on the BAT (i.e., a
behavioral measure of outcome), and on the cardiac response during the last minute of the BAT
(i.e., a physiological measure of outcome). Results revealed an interesting pattern, where change
in perceived self-efficacy was the strongest predictor of improvement on the Fear of Spider
Questionnaire, change in beliefs was the strongest predictor of improvement on the BAT and
change in both self-efficacy and beliefs predicted improvement in cardiac response when
performing the BAT (see Figure 9). Change in information processing never significantly
predicted improvement. These results shed some light on the treatment mechanism of in vivo
exposure. It is also interesting to see that changes in beliefs and self-efficacy that occur when
facing virtual stimuli predict changes in behavioral and physiological performance on a BAT.
Insert Figure 8 (illustration of images used in the pictorial emotional Stroop task) and
Figure 9 (results from Côté & Bouchard, submitted) here.
3.1 In virtuo exposure with children.
In virtuo exposure may be especially useful with children. Children may be attracted by
the “coolness” of VR, which could increase the likelihood that they will enroll in exposure-based
therapies. In a pilot study, Bouchard, St-Jacques, Robillard and Renaud (2007; Bouchard, 2011 )
used the pilot VR environment developed at UQO with Half-Life ™ and treated nine clinically
phobic children. The four-session treatment was adapted to children but otherwise similar to other
studies conducted at UQO. The researchers used a multiple baseline across subject design and
administered questionnaires at pre- and post-treatment. Statistical analyses revealed significant
improvement on all measures of phobia. Visual analyses of weekly reports of children’s fear of
spiders show that improvements followed the introduction of the treatment. However, the visual
analyses also showed that there was still room for improvement as many children were not rating
their fear at 0%.
A larger study from St-Jacques, Bouchard and Bélanger (2006) was conducted to test the
hypothesis that using in virtuo exposure would increase children’s motivation for therapy
compared to in vivo exposure. They recruited 31 children aged 8 to 15 who were clinically
phobic of spiders. Participants were assessed at pre-treatment, randomly assigned to either four
sessions of in virtuo exposure or four sessions of in vivo exposure, reassessed and then they all
received one session of in vivo exposure. Treatment manuals adapted for children were provided
to children and parents to inform them of the principles guiding the therapy and underlying
exposure, as well as to ascertain that therapy was delivered as planned. Adherence to the
treatments protocols was confirmed by random spot checks of audio recordings of therapy
sessions. In terms of efficacy at the end of the therapy, the statistical analyses could not detect
any significant difference between both forms of therapy (see Figure 10 for results on a modified
version of the Fear of Spider Questionnaire). Albeit non-significant, examination of effect-sizes
of the differences between both conditions from pre-treatment to the time everyone participated
in the last session with in vivo exposure revealed a medium effect. This suggests that a larger
sample could have detected significant differences, and thus that the addition of one in vivo
exposure session could be beneficial. But most surprisingly, and contrary to the researcher’s
hypotheses, in virtuo exposure did not increase children’s motivation towards therapy. In general,
children had a relatively strong self-determined motivation to engage in exposure-based therapy.
Pre-therapy and weekly assessments of motivation were lower in the in virtuo exposure, although
these differences were not statistically significant. The researchers raised several ad hoc
hypotheses to explain their results. One possibility being that children in the in virtuo condition
were more afraid of what the virtual spiders could look like and could do in the VR environment.
This is probably due to their fertile imagination (i.e., some kids were afraid that spiders would be
huge or aggressive) and highlights the importance of preparing children more carefully than
adults about what to expect during in virtuo exposure. This hypothesis was confirmed by Silva,
Bouchard & Bélanger (2011). As part of an attraction in a science museum depicting a virtual
environment used to treat phobias, they compared the apprehension of 533 people during an
immersion in virtual reality, just before opening doors that would lead to a spider or a rabbit.
Results revealed significantly less apprehension in adults compared to younger participants. The
lesson learned from this study is that therapists should describe to young participants what will
happen in the virtual environment, how frightening, disgusting or large the virtual spiders will be,
and what will the therapist do.
Another important finding from St-Jacques et al. (2006) this study is the demonstration
that treatment motivation, more specifically integrated extrinsic motivation, is a significant
predictor of success (sr2 = .49, p < .01). Given the importance of motivating children to come and
stay in therapy, in addition to the enticing effect of VR for children, more research should be
conducted on the power of VR to increase treatment motivation.
Insert Figure 10 (illustration of results from St-Jacques et al. 2006) here.
One of the most recent VR studies for arachnophobia treatment has explored how memory
consolidation might be enhanced by sleep (Kleim, Wilhelm, Temp, Margraf, Wiederhold &
Rasch, 2013). Although it is well established that memory consolidation after learning is
benefitted by sleep, this has not yet been researched in an emotional learning paradigm in
psychotherapy. Eighty subjects were recruited and a total of fifty who met inclusion
criteria underwent one-session VR exposure treatment. Exposure was done in a protocol
similar to the one used in a VR exposure study for acrophobia (de Quervain et al. 2011).
Following exposure, participants were assigned to either a sleep or wake condition.
Participants in the sleep condition were then taken to a different room in the lab to sleep for
90 minutes. Those in the wake condition watched a neutral National Geographic film for 90
minutes. After the 90 minute lapse, all participants completed a BAT. They then returned
to the lab 1 week later and completed a second BAT and questionnaires. Results indicated
that sleep improves therapeutic effectiveness, with participants showing a greater reduction
in both subjective anxiety and spider-related cognitions at one-week follow-up as compared
to patients who had not napped.
This study provided an initial exploration into the clinical application of memory research.
Some patients do not benefit from exposure therapy or benefit only to have the phobia later
return (Craske & Mystkowski, 2006). Napping after a therapy session may be one avenue
by which exposure-based treatments can be enhanced to increase response rates.
3.2 In virtuo exposure for other animal phobias.
Snake phobia (ophidiophobia) is more prevalent than arachnophobia, but is has received
much less attention from researchers in the field of VR. Only one research team has developed a
VR environment for snake phobics (see Parrott, Bowman & Ollendick, 2004). This environment
allows the user to see pictures of snakes, then snakes in several cages or outdoors and finally to
handle a fiber optic-based 3D bend and twist tubular sensor mimicking the curvature and feel of a
virtual snake, an approach that resembles the Hoffman et al. (2003) tactile augmentation. The
authors only mentioned that pilot testing with one patient was positive.
Botella, Juan, Baños, Alcañiz, Guillén and Rey (2005) took advantage of an innovative
technique to develop an environment to treat the specific phobia of cockroaches. They used
augmented reality (AR), a technology where the user wears a HMD that allows them to see
physical reality while virtual replicas of cockroaches are superimposed upon it (see Figure 11).
The authors report results from one single case where a 26-year old woman meeting the DSM-IV
diagnosis of specific phobia of cockroaches was treated with one hour of exposure using the
augmented reality system. After two months of baseline self-monitoring for an AB single-case
research design, the introduction of treatment led to an immediate and clear improvement. After
the intensive therapy session, the patient was able to open a terrarium and hold a cockroach using
a piece of cardboard. Results were maintained at the 2-month follow-up. More recently, a group
of researchers combined the use of a ‘‘serious game’’ to AR to treat phobias (Botella, Breton-
López, Quero, Baños, García-Palacios, Zaragoza & Alcaniz, 2011). In a pilot study with a 25 year
old woman diagnosed with cockroach phobia, Botella et al. (2011) used a mobile phone
application to create a game called The Cockroach Game where the user interacts with the insect
shown on screen, at different intensity levels, while trying to complete a puzzle. The only subject
to this study was instructed to play the game 9 days before undergoing a one hour long intensive
exposure session using AR. Once the exposure session was completed, the subject was
encouraged to resume playing the game for another 9 days. Results suggest that: (a) the use of a
serious game before undergoing an exposure session helped the patients by reducing her fear and
avoidance, (b) a single AR exposure session led to a reduction in levels of fear, avoidance and
catastrophic beliefs while providing higher BAT scores, and (c) assessment at the end of the
experimental trial showed that levels of fear, avoidance and catastrophic thoughts continued to
decrease during the following 9 days of playing the game. An improved version called The Catch
Me Game ,which usesa slightly different technology, is now being tested (Wrzesien et al., 2013).
Results with non-phobic participants are very encouraging (Wrzesien et al., 2013) and data are
now being collected on a clinical sample. ----------
Insert Figure 11 (images of augmented reality for the fear of cockroaches) here.
4.0 Available software.
There are very few VR program commercially available to treat the specific phobia of
spiders, snakes, cockroaches or small animals. In Virtuo (www.invirtuo.com) is distributing
virtual environments developed for phobias of spiders, snakes, dogs and cats. Each environment
allows users to face insects or animals of different sizes and shapes in various indoor and outdoor
contexts. Virtually Better (www.virtuallybetter.com) is also offering a virtual environment for
With specific phobias, therapists may be interested by simpler virtual environments, either
available for free or that can be built by the therapist using free development software. For
example, the early VR environments developed at UQO by modifying 3D games are available for
free download on the Cyberpsychology Lab’s website (w3.uqo.ca/cyberpsy). The two most
significant drawbacks of these programs are that: (a) the user must buy a legal copy of the game
before installing the modified version,(since versions of the game that are generally available on
the market are more recent but incompatible with previous versions, old versions are difficult to
find; and (b) there is no technical support to assist the user for troubleshooting and fixing
technical problems. The issue of keeping software versions updated is a significant one. For
example, the VR environment developed with Max Payne™ used in Côté and Bouchard (2005)
was built using Windows 98. As version of Windows evolved, updates and patches were needed.
The company distributing the game does not support these old versions anymore and integrating
new trackers and peripherals that require the latest versions of Windows or need updated drivers,
may not be possible. The apparent planned obsolescence of computer operating system, or
constant evolution and lack of support of past versions, is actually putting a significant toll on
developers. The latest virtual environment for spider phobia offered by In Virtuo was built for
Windows XP. While it was modified to run on Windows 7, Microsoft came up with Windows 8,
making the virtual environment incompatible with the latest version. Due to necessity of keeping
the version up to date which requires an investment of time and money, it makes the use of freely
distributed virtual environments very cumbersome. For the same reason, technical support is
often unavailable with freely distributed virtual environments. Unless the therapist has sufficient
time and technical skills, using free virtual environments often ends-up being a frustrating
A mid-term alternative is to use free or inexpensive software that allows building and
modifying your own environment. For example, NeuroVR (www.neurovr2.org) is a free program
that comes with a basic library of virtual scenes and objects and can be customized to put a
spider, a cockroach or a snake on the table of a virtual kitchen. And it is user-friendly. For
example, is has been used by bachelor degree students in psychology in courses delivered by the
first author of this chapter. As their main assignment, students have to create a new treatment for
a mental disorder of their choice, develop a therapeutic protocol and build the required virtual
environment. This can be done with no skills in computer programming and basic knowledge in
managing files and editing images. There is a community of NeuroVR users which can help
providing technical support. Although many researchers use this software to create efficient
applications, the options remain limited and the visual quality of the final product is not as
attractive as virtual environments developed with more expensive 3D editing and rendering
5. Relevant findings from studies using virtual reality approaches.
Outcome studies on in virtuo treatment of specific phobias of spiders, snakes and
cockroaches are in general methodologically less robust than what can be found for phobia of
flying or heights, an observation that is similar for research on the effectiveness of in vivo
exposure (Öst, 1997). Three studies compared the efficacy of in virtuo exposure to a control
condition (Garcia-Palacios et al., 2002; Hoffman et al., 2003; Michaliszyn et al., 2006). In all
three cases, VR was more effective than no treatment, except for one of three variables in
Hoffman et al. (2003) where the participants who did not have the tactile feedback performed just
like the controls on the level of fear felt during the BAT. The efficacy of in virtuo exposure in
controlled studies mirrors the observations from less controlled studies (Opris et al., 2012;
Meyerbröker & Emmelkamp, 2010). Michaliszyn et al. (2006) paid attention to effect sizes of the
comparison between treatments and didn’t find meaningful differences between in virtuo and in
vivo exposure. Only one controlled study tested VR with children and no significant difference
was found at post-treatment, although effect sizes suggest that the addition of one in vivo session
to the VR treatment may be beneficial. Two innovative studies used AR for the fear of
cockroaches (Botella et al., 2005; Botella et al., 2011). As mentioned above, the 2011 study
integrated the usage of a serious game before and after a one hour long exposition session.
Although these two studies are uncontrolled case studies, the results highlight the potential of this
technology. The patients’ improvements have been documented by multiple sources, such as self-
reports (e.g., Fear of Spider Questionnaire), physiological measures (e.g., heart rate variability),
automatic information processing (e.g., emotional Stroop task) and behavioral measures.
However, long-term follow-ups are needed to confirm claims about treatment efficacy. The
advantages of AR for exposure with people suffering from animal phobia are significant, both in
terms of costs and generalizability. The cost of developing a virtual environment is significantly
reduced if the developers only have to create and animate one object. With virtual reality, the
virtual spider has to be placed somewhere, on a virtual table which is in a virtual kitchen,
surrounded with other virtual objects that make the visual experience credible. Augmented
reality requires that the 3D object is overlaid on objects present in the physical reality so that the
developer only has to provide the virtual insect of an animal. A study comparing people’s
reactions to 3D spiders presented in augmented reality or in VR using a HMD technology or a
fully immersive virtual room (Baus, Bouchard, Gougeon & Roucaut, 2011) revealed that all three
technologies were as effective in inducing anxiety. In addition to cost, the other advantage is that
when AR will become portable and simpler to use, patients will be able bring the virtual spider
home and project it in several places that would be useful for exposure.Most of the behavior
avoidance tests involved approaching a live tarantula in a terrarium. In some cases, a perfect
score on the test would involve touching or holding the tarantula, which may be considered
extreme by some people. It may also be more difficult than BAT used in often-cited studies on in
vivo exposure, such as Öst’s work, where house spiders were used. At post-treatment, patients
were (on average) able to get very close to the tarantula, either with the lid of the terrarium open
or by touching it if closed, sometimes to the point of putting their hands in the terrarium.
However, the use of more similar BAT in terms of difficulty and hierarchy would help when
comparing the efficacy of different treatment protocols. A tentative comparison of pre- and post-
treatment scores on the Fear of Spider Questionnaire between studies using in virtuo exposure,
and with published studies using in vivo exposure (e.g., Murris & Merkelbach, 1996), reveals that
the severity of scores at pre-treatment are comparable across studies, and that improvement from
pre to post are similar to what is found in classical studies using in vivo exposure (e.g., all effect
sizes were larger than 2).
To test if VR may be used as an assessment and diagnostic tool, Mühlberger, Sperber,
Wieser and Pauli (2008) designed a virtual BAT to study the interaction between physiological
fear responses, approach behavior, reported fear and other subjective measures related to fear of
spiders. During their behavior avoidance test, the participant was immersed in VR using a HDM
in monoscopic display and the approach behavior of the participant toward the virtual spider was
carefully measured in centimeters. Patients underwent the test before and after undergoing eight
very brief (1 minute) in virtuo exposure sessions in the same virtual environment but with a
spider that looked different (i.e., using a different texture). Subjective measures were also taken.
Participants showed a reduction in negative beliefs regarding spiders, lower subjective fear and
an increase in approach behavior towards the spider. The documented change in approach
behavior suggests the possibility of using avoidance of virtual spiders as an assessment tool. This
is only a preliminary step that it needs to be substantiated with concomitant validity (e.g., with an
in vivo BAT), information about reliability, and using a different environment for the BAT and the
exposure treatment. But it remains an interesting avenue that could provide a wide range of
stimuli that would be very practical for therapists (e.g., the possibility to switch in a few clicks a
BAT for dogs, cats, snake, cows, etc.). Another interesting finding from this study was the
observed lack of significant change in heart rate and significant increase in skin conductance
from the pre to the post-exposure BAT. What this means is that even though participants
approached the virtual spider more closely at the post-exposure BAT, they did so with the same
level of physiological fear than in the pre-exposure BAT. Mühlberger et al. (2008) hypothesised
that physiological responses was still high as a result of closer approach behavior. Nevertheless,
these results are typical examples of desynchrony and discordance among modes of responses
(Haynes & O’Brian, 1999) and are replicating observations by (Côté & Bouchard, 2005).
Treatment protocols vary in duration, from 3 to 12 hours, with an average around four or five
one-hour sessions. Although the 3-hour/one-session treatment protocol validated by Öst is
intended to be a first step that should be followed by self-directed exposure at home post-therapy,
it has received extended empirical support. However, only one controlled study (Hoffman et al.,
2003) and two single case studies (Botella et al., 2005; Botella et al., 2011) successfully
condensed VR therapy to that extent. Research on the frequency and spacing between therapy
sessions has been prolific with in vivo exposure and should be addressed with in virtuo exposure
as well. For example, no study has tried to replicate the findings from Rowe and Craske (1998)
that frequent exposure-based therapy sessions early in therapy, followed by progressively spaced
the sessions, will be more effective than evenly spaced weekly therapy sessions.
Within therapy sessions, the treatment protocols do not usually keep the patient immersed
in VR for the entire duration of the exposure session (see Bouchard, Robillard, Larouche &
Loranger, 2012 for more details). In the first VR study, Carlin et al. (1997) paused every five
minutes to reduce the risks of virtual reality induced side effects. Indeed, looking into the HMD
for long periods of time may create eyestrain due to accommodation fatigue. However, stopping
the exposure after five minutes was not done in subsequent studies. To reduce the possibility of
eye-strain, it is suggested to take breaks roughly every 20 minutes and remove the HMD
(Stanney, Kennedy, Kingdon, 2002), although these breaks must be adjusted in order to allow
anxiety to decrease significantly during the exposure session.
During therapy sessions, almost every treatment protocol devoted the majority of the time
to in virtuo exposure. This is different from treatment protocols used for some other anxiety
disorders (e.g., fear of flying, social anxiety disorder), where significant therapy time was often
allocated to additional therapeutic strategies. Cognitive-restructuring, breathing retraining or
other coping strategies were not explicitly thought to arachnophobic patients, at least not in
studies using a written treatment manual. Patients were not encouraged to conduct self-exposure
exercises at home, either in vivo (for methodological purposes, such as keeping treatment as
purely VR as possible) or in virtuo (for practical reasons). The lack of homework is important to
notice since homework is included in traditional in vivo exposure therapies. In clinical practice,
therapists may want to add take-home exercises, and some portable and immersive applications
using iPads are now being tested (Bouchard et al., 2012). In terms of hardware, every VR
environment now works on affordable computers and with a wide range of VR devices, from the
most expensive to the most affordable. Only two studies report the presence of virtual reality
induced side effects (see Chapter 3 for more information about cybersickness). Apart from one
patient where cybersickness was significant, other participants generally experienced no or very
slight side effects. Further research is needed to ascertain if these symptoms are more related to
the anxiety felt during exposure than to VR, if they are caused by patient’s characteristics or the
mere immersion in VR, or if they are specific to the environment used (for example, users had to
move and walk a lot more in the virtual environments for arachnophobia than they do in a virtual
airplane). A few studies are actually raising concerns about the overlap between symptoms of
anxiety and virtual reality induced side effects (Bouchard, St-Jacques, Renaud & Wiederhold,
2009; Bouchard, Robillard, Renaud & Bernier, 2011). First, Bouchard et al. (2009) reported
normative data on the Simulator Sickness Questionnaire and observed that: (a) most participants
report only slight signs of negative side effects post-immersion, (b) many phobic patients report
symptoms that are on the list of this questionnaire before any immersion in VR, and (c) the
original scoring method, factor structure, and norms of the questionnaire may not be appropriate
for samples of phobic patients. In 2011, the same research team pursued their investigations and
questioned whether at least two items of the Simulator Sickness Questionnaire were not inflated
by anxiety (i.e., general discomfort and difficulty concentrating) and only four items were totally
independent of anxiety.
Given the growing body of data on disgust, researchers in VR should measure this
construct more often in their outcome studies. Practically, therapists seem to be including this
variable in their therapy, as they often draw a patient’s attention toward aspects of spiders and
their behavior that are more relevant to disgust than fear (e.g., spider web, the “grace” of spiders
walking, furry texture or shape of the legs).
One significant advantage of using virtual reality to conduct exposure is the possibility to
vary the context. As documented in the introduction of this chapter, varying contextual
information during the learning of new associations with of lack of threat is important for
generalization and prevention of relapse (Otto & Hofmann, 2010; Power et al., 2006). So far,
only one study has been conducted on the impact of systematically varying the context of in
virtuo exposure (Shiban, Pauli & Mühlberger, 2013). Shiban et al. (2013) used a very well
controlled experimental paradigm where they exposed in virtuo spider phobics to a spider in an
empty room for one session that lasted less than an hour, using a HMD and a 6-dof motion
tracker. Participants were randomly assigned to five brief in virtuo exposure exercises in a room
that either: (a) remained exactly the same color (walls, floor, roof and lighting) for all exercices,
or (b) changed color for each exercise. A pre and post session BAT involving a live tarantula
revealed significantly more improvement in participants who were exposed to the virtual spider
in different contexts for each immersion compared to those expose in a single context. The level
of fear experienced during and between the exercises was also related to the change in contexts,
with greeted within? session reduction of fear for those treated in a variety of contexts. Because
the experiment involved only changing the color of the room, it is highly probable that more
important variations in context (e.g., exposure exercises in the kitchen, in the bedroom, on the
porch, on the grass) would have an ever stronger impact. More work on this topic should be
conducted also to orient developers of VR environments to the kind of scenarios that must be
developed. For now, VR environments for specific phobiasinclude several varieties of feared
stimuli that are encountered in a variety of locations while they are engaged in a variety of
behaviors. To what extent does this variety of contexts facilitate generalization? It is worthy to
note that in the environment developed using the game Max Payne, the behaviors of the virtual
spiders were not realistic. Even if it was not detrimental for the therapy, this deserves to be
studied more often since it doesn’t allow patients to learn how spiders really behave.
It is practical to use arachnophobia for conducting experimental research in VR, just as it
is the case with in vivo exposure. Two studies have tackled the task of investigating the treatment
mechanism of in virtuo exposure. Hoffman et al. (2003) revealed that adding a tactile feeling may
increase treatment efficacy. It remains to be seen whether the increase in efficacy would be
caused by the increase in the feeling of presence, or if it relates more to the inclusion of an
additional context (the feeling of touch) or an additional sensory modality, to increases in self-
efficacy, to the development of stronger anti-phobic behavior or to more tangible evidences of the
lack of danger. More experimental research on this topic is warranted. The study by Côté and
Bouchard (2005) showed that even if spiders are virtual, in vivo exposure initiates change in
process variables such as dysfunctional beliefs, self-efficacy and an emotional Stroop task.
However, only changes in dysfunctional beliefs and self-efficacy predicted treatment outcome.
The emotional Stroop task is often used as an index of changes in the fear structure, a concept
relevant to Foa and Kozak’s (1986) emotional processing theory. This influential theory in the
field of anxiety disorders is often cited as the explanation for the effectiveness of in virtuo
exposure (North, North & Coble, 1996). However, in light of the current conceptualization of the
mechanisms involved in exposure illustrated in the introduction of this chapter, Côté and
Bouchard’s (2009) results may illustrate the learning of safe associations with the feared stimuli
in terms of perceived consequences (involving threat or disgust) and perceived self-efficacy,
along with fear structures that are not so much modified as inhibited but still present to some
extent. Further experimental studies are needed to explain why the emotional Stroop task did not
predict outcome (Côté & Bouchard, 2009). Nevertheless, knowing that change in beliefs and self-
efficacy are key predictors of outcome is clinically very important to therapists using VR.
Therapists must use patients’ gains in therapy to foster their perceived self-efficacy, guide
patients’ attention to events that disprove their dysfunctional beliefs and conduct post-exposure
reviews of what has been learned during the immersion. The contribution of self-efficacy to
therapeutic success may also explain the advantage of using biofeedback during in virtuo
exposure for fear of flying (Wiederhold, 1999).
No study has yet documented the neurological correlate of improvements after VR
therapy. It is assumed that in virtuo exposure is simply a different form of exposure which aims
to develop new mental associations between the stimuli and lack of danger. It therefore remains
to be tested whether in virtuo exposure involves change in the same brain areas as in vivo
exposure. However, a few studies conducted with claustrophobics used VR to fully standardize
the exposure treatment and test the efficacy of a drug that can boost the occurrence of emotional
learning in the limbic system (see Ressler et al., 2004 in the following chapter).
It is commonly believed that VR is an innovative form of therapy that could make
exposure-based therapies more attractive to patients, or at least make exposure more acceptable.
Two studies performed by Garcia-Palacios, Hoffman, See, Tsai and Botella (2001) confirm
people’s preference for in virtuo exposure over in vivo exposure. In the first study, 87
undergraduate students scoring high on a brief assessment of fear of spiders were provided
standardized information about in vivo and in virtuo exposure and asked to indicate their
willingness to receive each form of therapy. When asked if they would consider several sessions
of free treatment, 17.4% said they would definitely not engage in in vivo exposure, compared to
only 4.6% who said they would definitely not try VR. On a forced-choice question, 81% chose in
virtuo exposure compared to only 19% who chose in vivo. In the second study, they used the
same methodology with 75 students highly fearful of spiders to contrast their preferences
between multiple sessions of in virtuo exposure compared to one 3-hour session of in vivo
exposure. In this case, 34.7% said they would definitely not do in vivo exposure, compared to 8%
who said they would not do in virtuo exposure. On the forced-choice question, 89.2% chose VR
with only 10.8% choosing in vivo. However, these results were obtained with adults. When St-
Jacques et al. (2006) compared children’s actual motivation towards therapy just after they’ve
been told that they would receive in virtuo or in vivo exposure therapy, results were slightly
different. Motivation was not different for the in virtuo condition. This finding may very well be
due to children entertaining frightening expectations about what could happen during VR
exposure. It could also be explained by methodological differences between Garcia-Palacios’ and
St-Jacque’s studies. One measured what type of therapy adults would chose if they were to seek
treatment and the other one measured motivation of children already seeking treatment. Still, it
raises the possibility that acceptance and attractiveness of in virtuo exposure could be more
complex with children than originally thought.
The overall results of completed research validate the potential of in virtuo exposure to
treat arachnophobia. If one wants to rigorously prove that in virtuo exposure is specifically
effective for spider phobia, then additional trials are needed. The current ones are very good but
can be criticized on the grounds of control conditions, sample size or long-term follow-ups. But
considered in the general context of validating VR for the treatment of specific phobias, the
current studies are adding significant support to the growing body of evidence that in virtuo
exposure is an effective treatment. Some researchers are also developing new applications of VR
to other insects (cockroaches) and animals (snakes), so further outcome studies are expected.
A useful contribution to VR studies with people suffering from arachnophobia is for
examining variables related to treatment process. Tactile feedback may increase the efficacy of
VR treatment. What remains to be seen is whether this is because it increases the feeling of
presence or if it is via other mechanisms such as self-efficacy or the addition of physical motor
approach or avoidance response of the arm towards the spider. Changes in cognitive information
processing were also observed but did not predict treatment outcome. Rather, treatment success
appears to be related to change in dysfunctional beliefs and self-efficacy. Given the importance of
varying the contexts of exposure to maximize its effectiveness, it is interesting to note that most
VR environments were developed with variety in mind. Finally, VR appears to be an attractive
form of therapy, an asset that still needs to be studied more thoroughly.
Since it is easy to find spiders for therapy, one may wonder why researchers found an
interest in the use of VR. Many VR studies were conducted with arachnophobia for
methodological reasons. First, given the availability of spiders, researchers could compare in
virtuo exposure with the gold-standard in vivo exposure. This is not possible with fear of flying,
for example, where the exposure program can hardly be provided entirely in vivo with actual
flights. Second, the availability of spiders also facilitates the use of safe, simple and affordable
BAT. VR also offers to the therapist a degree of control and variety of contexts that is impossible
to have even with live spiders. Fourth, the possibility to use physical and virtual spiders is a
significant asset for experimental research on factors that make VR effective. Finally, it seemed
natural for researchers to begin clinical research on VR with more circumscribed disorders and
then move on to study phobias where physical stimuli cannot be used in vivo (e.g., fear of
thunderstorm) and to more complex anxiety disorders such as social anxiety or panic disorder.
Abramowitz, J. S. (2013). The practice of exposure therapy: Relevance of cognitive-behavioral
theory and extinction theory. Behavior Therapy, 44, 548-558.
Abramowitz, J. S., Deacon, B. J., & Whiteside, S. P. H. (2011). Exposure therapy for anxiety.
Principles and practice. New York: The Guilford Press.
American Psychiatric Association: APA. (2000). Diagnostic and Statistical Manual of Mental
Disorders Fourth Edition Text Revision. Washington, DC: American Psychiatric
Bandura, A. (1986). Social foundations of thoughts and action: A social cognitive theory.
Englewoods Cliffs: Prentice Hall.
Baus, O., Bouchard, S., Gougeon, V., & Roucaut, F.-X. (2011). Comparison of Anxiety in
Response to Virtual Spiders While Immersed in Augmented Reality, Head-Mounted
Display, or CAVE-Like System. Journal of Cybertherapy and Rehabilitation, 4(2), 171-
Botella, C., Breton-López, J., Quero, S., Baños, R.M., García-Palacios, A., Zaragoza, I., &
Alcaniz, M. (2011). Treating cockroach phobia using a serious game on a mobile phone
and augmented reality exposure: A single case study. Computers in Human Behavior, 27,
Botella, C.M., Juan, M.C., Baños, R.M., Alcañiz, M., Guillén, V., & Rey, B. (2005). Mixing
realities? An application of augmented reality for the treatment of cockroach phobia.
CyberPsychology & Behavior, 8(2), 162-171.
Bouchard, S. (2011). Could virtual reality be effective in treating children with phobias? Expert
Review of Neurotherapeutics, 11(2), 207-213.
Bouchard, S., Côté, S., Robillard, G., St-Jacques, J., & Renaud, P. (2006). Effectiveness of virtual
reality exposure in the treatment of arachnophobia using 3D games. Technology and
Health Care, 14(1), 19-27.
Bouchard, S., St-Jacques, J., Robillard, G., & Renaud, P. (2007). Efficacité d’un traitement
d’exposition en réalité virtuelle pour le traitement de l’arachnophobie chez l’enfant : Une
étude pilote. Journal de Thérapie Comportementale et Cognitive, 17 (3), 101-108.
Bouchard, S., St-Jacques, J., Renaud, P., & Wiederhold, B.K. (2009). Side effects of immersions
in virtual reality for people suffering from anxiety disorders. Journal of Cybertherapy and
Rehabilitation, 2(2), 127-137.
Bouchard, S., Robillard, G., Larouche, S., & Loranger, C. (2012). Description of a treatment
manual for in virtuo exposure with specific phobia. In: C. Eichenberg (Ed.): Virtual
Reality in Psychological, Medical and Pedagogical Applications (ch. 4, pp. 82-108).
Rijeka (Croatia): InTech.Bouchard, S. Robillard, G., Renaud, P., & Bernier, F. (2011).
Exploring new dimensions in the assessment of virtual reality induced side-effects.
Journal of Computer and Information Technology, 1(3), 20-32.
Bourdon, K.H., Boyd, J.H., Rae, D.S., & Burns, B.J. (1988). Gender differences in phobias :
Results of a ECA community survey. Journal of Anxiety Disorders, 2, 227-241.
Bouton, M.E. (2007). Learning and behaviour: A contemporary synthesis. Sunderland, Mass. :
Carlin, A.S., Hoffman, H.G., & Weghorst, S. (1997). Virtual reality and tactile augmentation in
the treatment of spider phobia: A case report. Behaviour Research & Therapy, 35(2),
Côté, S. & Bouchard, S. (2009). Cognitive mechanisms underlying virtual reality exposure.
Cyberpsychology & Behavior, 12(2), 121-129.Côté, S. & Bouchard, S. (2005).
Documenting the efficacy of virtual reality exposure with psychophysiological and
information processing measures. Applied Psychophysiology and Biofeedback, 30(3),
Craske, M.G. & Mystkowski, J.L. (2006). Exposure therapy and extinction: clinical studies. In
Fear and Learning: Basic Science to Clnical Application (ed. D.H.M.G. Craske and D.
Vansteenwegen), pp. 217-234. American Psychological Assoication: Washington, DC.
Curtis, G.C., Magee, W.J., Eaton, W.W., Wittchen, H.-U., & Kessler, R.C. (1998). Specific fears
and phobias: Epidemiology and classification. British Journal of Psychiatry. 173, 212-
de Quervain, D.F.G., Bentz, D., Michael, T., Bolt, O.., Wiederhold, B.K., Margraf, J., & Wilhelm,
F.H. (2011). Glucocorticoids enhance extinction-based psychotherapy. Proceedings of
the National Academy of Science. USA, 108, 6621-6625.
Dewis, L.M., Kirkby, K.C., Martin, F., Daniels, B.A., Gilroy, L.J., & Menzies, R.G. (2001).
Computer-aided vicarious exposure versus live graded exposure for spider phobia in
children. Journal of Behavior Therapy, 32, 17-27.
Edwards, S. & Salkovskis, P.M. (2006). An experimental demonstration that fear, but not disgust,
is associated with return of fear in phobias. Anxiety Disorders, 20, 58-71.
Foa, E.B., & Kozak, M.J. (1986). Emotional processing of fear: Exposure to corrective
information. Psychological bulletin, 99, 20-35.
Fredrickson, M., Annas, P., Fischer, H., & Wik, G. (1996). Gender and age differences in the
prevalence of specific fears and phobias. Behaviour Research & Therapy, 26, 241-244.
Garcia-Palacios, A., Hoffman, H., Carlin, A., Furness III, T.A., & Botella, C. (2002). Virtual
reality in the treatment of spider phobia: A controlled study. Behaviour Research and
Therapy, 40, 983-993.
Garcia-Palacios, A., Hoffman, H., See, S.K., Tsai, A., & Botella, C. (2001). Redefining
therapeutic success with virtual reality exposure therapy. CyberPsychology and Behavior,
Gilroy, L.J., Kirkby, K.C., & Daniels, B.A., Menzies, R.G., & Montgomery, I.M. (2003). Long-
term follow-up of computer-aided vicarious exposure versus live graded exposure in the
treatment of spider phobia. Behavior Therapy, 34, 65-76.
Gilroy, L.J., Kirby, K.C., Daniels, B.A., Menzies, R.G., & Montgomery, I.M. (2000). Controlled
comparison of computer-aided vicarious exposure versus live exposure in the treatment of
spider phobia. Behavior Therapy, 31(4), 733-744.
Götestam, K.G. (2002). One session group treatment of spider phobia by direct or modelled
exposure. Cognitive Behaviour Therapy, 31(1), 18-24.
Haynes, S. N., & O.Brien, W.H. (2000). Principles and Practice of behavioral assessment. New
Heading, K., Kirkby, K.C., Martin, F., Daniels, B.A., Gilroy, L.J., & Menzies, R.G. (2001).
Controlled comparison of single-session treatments for spider phobia: Live graded
exposure alone versus computer-aided vicarious exposure.
Hellström, K. & Öst, L.-G. (1995). One-session therapist directed exposure vs two forms of
manual directed self-exposure in the treatment of spider phobia. Behaviour Research and
Therapy, 33(8), 959-965.
Hoffman, H. (1998). VR: A new tool for interdisciplinary psychology research CyberPsychology
and Behavior, 1(2), 195-200.
Hoffman, H., Garcia-Palacios, A., Carlin, A., Furness III, T.A., & Botella, C. (2003). Interfaces
that heal: Coupling real and virtual objects to treat spider phobia. International Journal of
Human-Computer Interaction, 16(2), 283–300.
Johnstone, K.A. & Page, A.C. (2004). Attention to phobic stimuli during exposure: The effect of
distraction on anxiety reduction, self-efficacy and perceived control. Behaviour Research
and Therapy, 42, 249-275.
Kleim, B., Wilhelm, F.H., Temp, L., Margraf, J., Wiederhold, B.K., & Rasch, B. Sleep enhances
exposure therapy. (2013). Psychological Medicine, 10, 1-9.
Krijn, M., Emmelkamp, P. M. G., Ólafsson, R. P., Schuemie, M. J., & Van Der Mast, A. P. G.
(2007). Do self-statements enhance the effectiveness of virtual reality exposure therapy?
A comparative evaluation in acrophobia. Cyberpsychology & Behavior, 10 (3), 362-370.
Larson, C.L., Schaefer, H.S., Siegle, G.J., Jackson, C.A.B., & Anderle, M.J. (2006). Fear is fast
in phobic individuals: Amygdala activation in response to fear-relevant stimuli.
Biological Psychiatry, 60, 410-417.
Marshall, W.L., Gauthier, J., Christie, M.M., Currie, D.W., & Gordon, A. (1977). Flooding
therapy: Effectiveness, stimulus characteristics, and the value of brief in vivo exposure.
Behaviour Research and Therapy, 15(1), 79-87.
McNally, R.J. (2002). On nonassociative fear emergence. Behaviour Research and Therapy, 40,
Meyerbroeker, K. & Emmelkamp, P.M.G. (2010). Virtual reality exposure therapy in anxiety
disorders: a systematic review of process-and-outcome studies. Depression and Anxiety,
Michaliszyn, D.R., Marchand, A., Bouchard, S., Martel, M.-O., & Poirier-Bisson, J., (2010). A
randomized control trial of in virtuto and in vivo exposure for spider phobia.
Cyberpsychology, Behavior and Social Networking, 13(6), 689-695.
Michaliszyn, D., Marchand, A., Martel, M.-O., Gaucher, M. (2006). Predicting treatment
outcome for arachnophobia’s virtual reality therapy through measures of fear. Poster
presented at the 11th Annual CyberTherapy Conference 2006, Gatineau, June 13-15.
Mineka, S., Mystkowski, J.L., Hladek, D., & Rodriguez, B.I. (1999). The effects of changing
contexts on return of fear following exposure therapy for spider fear. Journal of
Consulting and Clinical Psychology, 67, 4, 599-604.
Mineka, S., & Thomas, C. (1999). Mechanisms of change in exposure therapy for anxiety
disorders. In T. Dagleish and M. Powers (Eds.), Handbook of cognition et emotion (pp.
747-764). New York: John Wiley and Sons.
Mühlberger, A., Sperber, M., Wieser, M. J., & Pauli, P. (2008). A virtual reality behavior
avoidance test (VR-BAT) for the assessment of spider phobia. Journal of CyberTherapy
& Rehabilitation, 1 (2), 147-158.
Mulkens, S.A.N., de Jong, P.J., & Merckelbach, H. (1996). Disgust and spider phobia. Journal of
Abnormal Psychology, 105, 464-468.
Mohlman, J., & Zinbarg, R. E. (2000). What kind of attention is necessary for fear reduction? An
empirical test of the emotional processing model. Behavior Therapy, 31, 113-133.
Murris, P. & Merkelbach, H. (1996). A comparison of two spider fear questionnaires. Journal of
Behavioural Therapy and Experimental Psychiatry, 27(3), 241-244.
Mystkowski, J., Craske, M.G., & Echiverri, A.M. (2002). Treatment context and return of fear in
spider phobia. Behavior Therapy, 33, 399-416.
Mystkowski, J.L., Craske, M.G., Echiverri, A.M., & Labus, J.S. (2006). Mental reinstatement of
context and return of fear in spider-fearful participants. Behavior Therapy, 37, 49-60.
Mystkowski, J.L., Mineka, S., Vernon, L.L., & Zinbarg, R.E. (2003). Changes in caffeine states
enhance return of fear in spider phobia. Journal of Consulting and Clinical Psychology,
North, M.M., North, S.M., and Coble, J.R. (1996). Virtual Reality Therapy. An Innovative
Paradigm. CO: IPI Press.
Opris, D., Pintea, S., Garcia-Palacios, A., Botella, C., Szamoskozi, S., & David, D. (2012).
Virtual reality exposure therapy in anxiety disorders: A quantitative meta-analysis.
Depression and Anxiety, 29, 85-93.Öst, L.-G. (1997). Rapid treatment of specific phobias.
In G.C.L. Davey (Ed.), Phobias: A handbook of theory, research and treatment (pp.227-
246). Chichester: John Wiley.
Öst, L.G. (1987). Age at onset in different phobias. Journal of Abnormal Psychology, 96, 223-
Öst, L.-G., Ferebee, I., & Furmark, T. (1997). One session group therapy of spider phobia: direct
versus indirect treatments. Behaviour Research and Therapy, 35, 721-732.
Öst, L.G., Salkovskis, L.-G.P.M., & Hellström, K. (1991). One-session therapist directed
exposure vs. self-exposure in the treatment of spider phobia. Behavior Therapy, 22, 407-
Otto, M. W., & Hofmann, S. G. (2010). Avoiding treatment failures in the anxiety disorders. New
Paquette, V., Lévesque, J., Mensour, B., Leroux, J.-M., Beaudoin, G., Bourgouin, P., &
Beauregard, M. (2003). « Change the mind and you change the brain » : Effects of
cognitive-behavioral therapy on the neural correlates of spider phobia. NeuroImage, 18,
Parrott, M., Bowman, D., & Ollendick, T. (2004). An immersive virtual environment for the
treatment of ophidiophobia. Presentation at the 9th Annual CyberTherapy Conference
Phillips, M. L., Drevets, W. C., Rauch, S. L., & Lane, R. (2003). Neurobiology of emotion
perception II: Implications for major psychiatric disorders. Biological Psychiatry, 54,
Powers, M.B., Smits, J.A.J., Leyro, & Otto, M.W. (2006). Translational research perspectives on
maximizing the effectiveness of exposure therapy. In D.C.S. Richards & D.L. Lauterbach
(Eds.), Handbook of exposure therapies (pp. 109-126), Burlington: Academic Press.
Rachman, S.J. (1966). Studies in desensitization: II. Flooding. Behaviour Research and Therapy,
Ressler, K.J., Rothbaum, B.O., Tannenbaum, L., Anderson, P., Graap, K., Zimand, E., & al.
(2004). Cognitive enhancers an adjuncts to psychotherapy: Use of D-Cycloserine in
phobic individuals to facilitate extinction of fear. Archives of General Psychiatry, 61(11),
Richards, D.C.S., Lauterbach, D., & Gloster, A.T. (2006). Description, mechanisms of action, and
assessment. In D.C.S. Richards & D.L. Lauterbach (Eds.), Handbook of exposure
therapies (pp. 1-28), Burlington: Academic Press.Rowe, M.K., & Craske, M.G. (1998).
Effects of varied-stimulus exposure training on fear reduction and return of fear.
Behaviour Research and Therapy, 36, 719-734.
Schienle, A., Schäfer, A., Stark, R., & Vaitl, D. (2009). Long-term effects of cognitive behavior
therapy on brain activation in spider phobia. Psychiatry Research: Neuroimaging, 172,
Silva, C., Bouchard, S., & Bélanger, C. (2011). Youths are more apprehensive and frightened
than adults by a virtual environment used to treat arachnophobia. Journal of
Cybertherapy and Rehabilitation, 4(2), 200-201.
Shiban, Y., Pauli, P., & Mühlberger, A. (2013). Effect of multiple context exposure on renewal in
spider phobia. Behaviour Research and Therapy, 51 (68-74).
Smith, K.L., Kirkby, K.C., Montgomery, I.M., & Daniels, B.A. (1997) Computer-delivered
modeling of exposure for spider phobia: Relevant versus irrelevant exposure. Journal of
Anxiety Disorders, 11(5), 489-497.
Smiths, J.A.J., Telch, M.J., & Randall, P.K. (2002). An examination of the decline in fear and
disgust during exposure-based treatment. Behaviour Research and Therapy, 40, 1243-
Stanney, K.M., Kennedy, R.S., & Kingdon, K. (2002). Virtual environment protocols. In K.M.
Stanney, Handbook of virtual environments (pp.721-730).
Stinson, F.S., Dawson, D.A., Chou, S.P., Smith, S., Goldstein, R.B., Ruan, W.J., & Grant, B.F.
(2007). The epidemiology of DSM-IV specific phobia in the USA: results from the
National Epidemiologic Survey on Alcohol and Related Conditions. Psychological
Medicine, 37, 1047-1059.St-Jacques, J., Bouchard, S., & Bélanger, C. (2006). Does
Virtual Reality Motivates Children to Do Exposure? Oral presentation at the 11 th
CyberTherapy Conference, Gatineau (Québec), June 12.
Straube, T. ,Glauer, M., Dilger, S., Mentzel, H.-J., & Miltner, W.H.R. (2006). Effects of
cognitive-beavioral therapy on brain activation in specific phobia. NeuroImage, 29, 125-
Szymanski, J., & O’Donoghue, W. (1995). Fear of spiders questionnaire. Journal Behavior
Therapy and Experimental Psychiatry, 26(1), 31-34.
Telch, M.J. (2004). Pushing the envelope on treatments for phobia. In M. Maj, H.S. Akiskal, J.J.
López-Ibor, & A. Okasha (Eds.), Phobias (pp. 232-234).Chichester: John Wiley.
Vansteenwegen, D., Vervliet, B., Hermans, D., Thewissen, R., & Eelen, P. (2007). Verbal,
behavioural and physiological assessment of the generalization of exposure-based fear
reduction in a spider-anxious population. Behaviour Research and Therapy, 45(2), 291-
Watts, F.N. (1986). Cognitive processing in phobias. Behavioural Psychotherapy, 14, 295-301.
Wiederhold, B.K. (1999). A comparison of imaginal exposure and virtual reality exposure for
the treatment of fear of flying. (Doctoral dissertation, California School of Professional
Psychology, 1999). Dissertations Abstracts International.
Wolitsky, K.B., Rellini, A.H., & Telch, M.J. (2005). Investigating the mechanisms of change
during exposure-based treatments for acrophobia. Poster presentation at the meeting of
Anxiety Disorder Association of America, Seattle.
Woody, S.R., McLean, C., & Klassen, T. (2005). Disgust as a motivator of avoidance of spiders.
Journal of Anxiety Disorders, 19, 461-475.
World Health Organization (1992). The ICD-10 classification of mental and behavioural
disorders. Geneva: WHO.
Figure 1. Images from the computer-aided vicarious exposure program developed at the
University of Tasmania.
Figure 2. Picture of Hunter Hoffman with a patient looking at a spider in Spider World. Note the
patient trying to touch a toy spider. The HMD displayed in this picture is not the one used by
Carlin et al. (1997).
Figure 3. Results from Hoffman et al. (2003) on a modified version of the Fear of Spider
Figure 4. Results from Garcia-Palacios et al. (2002) on the Fear of Spider Questionnaire.
Figure 5. Screenshots from the first VR environment developed at UQO using Half-Life™ 3D
Figure 6. Three screenshots from the second VR environment developed at UQO using the Max
Payne™ 3D game engine (taken in Level 1, Level 3 and with the largest spider found in Level 3).
Figure 7. Results from Michaliszyn et al. (submitted) on the Fear of Spider Questionnaire.
Figure 8. Illustration of images used in the pictorial emotional Stroop task by Côté and Bouchard
Figure 9. Percentage of variance explained by three predictors (beliefs, self-efficacy and
emotional processing) on three outcome measures (global, behavioral and physiological) for in
virtuo exposure for fear of spiders.
Note: * indicates predictors that were significant.
Figure 10. Results of 31 children on a modified version of the Fear of Spider Questionnaire when
measured after four sessions of either in virtuo or in vivo exposure and after one final session of
in vivo exposure.
Figure 11. Reproduction of what a user can see in Botella’s et al. (2005) augmented reality
program for the specific phobia of cockroaches. Note that everything seen by the participant
through the HMD is the physical reality, including the therapist’s and the participant’s hands,
except for the cockroaches that are virtual.