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Review
Virtual Reality Technology as an Educational and Intervention
Tool for Children with Autism Spectrum Disorder: Current
Perspectives and Future Directions
Minyue Zhang 1, Hongwei Ding 1,* and Yang Zhang 2,*
1 Speech-Language-Hearing Center, School of Foreign Languages, Shanghai Jiao Tong University, Shanghai
200240, China; zhang.my@sjtu.edu.cn (M.Z.)
2 Department of Speech-Language-Hearing Sciences, University of Minnesota, Minneapolis, MN 55455, USA
* Correspondence: hwding@sjtu.edu.cn (H.D.); zhanglab@umn.edu (Y.Z.); Tel.: +1-612-624-7878 (Y.Z.)
Abstract: Virtual reality (VR) technology gains theoretical support from rehabilitation and peda-
gogical theories and offers a variety of capabilities in educational and interventional contexts with
affordable products. VR is attracting increasing attention in the medical and healthcare industry as
it provides fully interactive three-dimensional simulations of real-world settings and social situa-
tions, which are particularly suitable for cognitive and performance training including social and
interaction skills. The worldwide rising trend in the prevalence of autism spectrum disorder calls
for innovative and efficacious techniques for assessment and treatment. The article offers a sum-
mary of current perspectives and evidence-based applications of VR technology as an educational
and intervention tool for children with autism spectrum disorder, with a primary focus on social
communication including social functioning, emotion recognition, and speech and language. Tech-
nology- and design-related limitations as well as the disputes over the application of virtual reality
to autism research and therapy are discussed and future directions of this emerging field are high-
lighted with regards to application expansion and improvement, technology enhancement, and the
development of brain-based research and theoretical models.
Keywords: virtual reality; autism spectrum disorder; education; intervention; childhood and ado-
lescence
Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized
by difficulties/differences in social communication, interaction, language, cognition, and
behavioral activities across a variety of contexts [1]. Although the degree of impairment
varies tremendously among individuals with ASD, these symptoms can lead to social ex-
clusion and pose significant obstacles to maintaining and sustaining friendships and em-
ployment (in the case of affected adult individuals) [2]. To address the problems, tradi-
tional intervention approaches generally require intensive support under the direct su-
pervision of well-trained professionals. However, professional care and amenities are not
always accessible to many individuals with ASD due to unaffordable intervention costs
and/or lack of available qualified therapists [3], which calls for the development of new
and efficacious tools for ASD assessment and intervention. In recent years, there has been
a rapid advance in the development of virtual reality (VR) technology and its uses for
leisure and education. VR has also emerged as an effective approach in various areas of
the health field, such as diagnosis [4], rehabilitation [5], surgical training [6], and mental
health treatment [7]. The wide application of this technology has inspired many research-
ers to consider the potential and effectiveness of implementing VR technology for the as-
sessment and treatment of ASD [8-11]. This article attempts to provide an updated review
of the emerging field to summarize the current perspectives and identify future directions.
1. VR as a Powerful Tool: Technology-driven Pedagogical and Intervention Platform
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© 2022 by the author(s). Distributed under a Creative Commons CC BY license.
1.1. Theoretical Underpinnings and Models for VR Training and Intervention
Many theories on rehabilitation and education support the use of interactive media
like VR, which can not only simulate the real world but also provide enhanced experiences
that are fully controlled and better suited for learning and practice. For instance, cognitive
rehabilitation theory (CRT), based on neuropsychological and cognitive psychological
models [12], is an integrated approach involving individualized training of real-world
tasks through a variety of techniques for daily functioning improvement [13]. It empha-
sizes the significance of the individual’s social system, personal and environmental con-
text [14] and acknowledges the complicated interplay of these contexts and rehabilitation
techniques [15]. Following these essential ideas, researchers have attempted to develop
therapies and build models for clinical rehabilitation and intervention. For example,
Dhamodharan, et al. [8] proposed an evidence-based cognitive and occupational therapy
using an interactive VR environment. Their model analyzes three levels of decreasing
functioning and cognitive impairment in children with autism, including attention, rea-
soning, emotion, social behavior, language understanding, and decision making, and
aims to promisingly improve the mental state of autistic children and their life skills.
In addition to VR application in clinical intervention, many pedagogical theories also
support its use as an educational tool in school activities. Classic pedagogical theories in-
cluding constructivist learning, situated learning, and engagement theory all endorse the
idea of VR integration into education [16-18]. The constructivist philosophy considers
knowledge to be constructed through learners’ interaction with the environment. Situated
learning holds that learning is realized through continuous participation in the authentic
activities in the community of practice. Similarly, the fundamental idea underlying en-
gagement theory highlights the necessity of learners being meaningfully engaged in learn-
ing activities via interpersonal interaction and task completion. In these theories, VR inte-
gration is envisioned as the platform that enables full participation and facilitates all as-
pects of interaction and engagement. Furthermore, newly-advanced theories of pedagogy
such as experiential learning and affective learning provide even greater support for the
investigation of how VR technologies can be harnessed in education and learning.
The basic idea of experiential learning is to provide a learning environment or con-
text for learners to actively experiment and test the hypotheses conceptualized from their
previous experiences, and generate new knowledge and experiences for new situations.
It is represented as an iterative learning cycle consisting of four steps, i.e., concrete expe-
rience (learners’ active experiencing and thinking in a given situation), reflective observa-
tion (analysis of observed outcomes of the experiencing), abstract conceptualization (sit-
uation understanding and hypothesis proposing), and active experimentation (hypothesis
testing through active experimenting in new situations) [19]. Experiential learning has be-
come one of the most widely applied pedagogical theories for VR integration into educa-
tion, because interactive media technologies, especially immersive virtual environments
(VEs), can allow learners to actively experiment and reflectively observe in a safe and au-
thentic environment [20]. VEs can be better suited and advantageous for promoting learn-
ing as the VR technology allows flexibility and control to remove competing and often-
times confusing sources of information from the real-world social and environmental con-
text and manipulate variables such as break intervals and other motivational factors/in-
centives to solidify learning [21]. The realism of the VEs as a design feature of the technol-
ogy can also facilitate the transfer of important skills into everyday lives [22-24].
Another important concept in the creation of VR learning environments involves so-
cio-affective mediation. The Cognitive-Affective-Social Theory of Learning in digital En-
vironments (CASTLE) proposes that social cues in the digital materials and environment
help activate social schemata in learners while reaping the benefits of enhanced social,
motivational, emotional and metacognitive processes [25]. Researchers [e.g., 25] support-
ing affective learning purportedly introduce the impact of affective factors in the learning
process. Kort, et al. [26] developed a model that takes into consideration the interaction
between emotions and learning and suggested that if a learner's affective state is
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recognized and responded appropriately, learning will proceed at an optimal pace. Simi-
larly, Ip, et al. [27] proposed a pedagogical model for affective learning, namely, the Smart
Ambience for Affective Learning (SAMAL) Model, which considers the interplay between
body, mind and emotion during the learning process. Affective learning theories provide
solid theoretical support for VR application in learning and education as empirical evi-
dence has demonstrated that VR positively influences the affective experience that learn-
ers perceive, enhances their learning engagement as well as their motivation to learn, and
ultimately leads to better learning effectiveness [28].
As the target knowledge and skills are often multi-layered with different steps or
levels of mastery, scalability or proper stratification for programmatic progress to im-
prove usability is necessary. In recent years, interdisciplinary educators have started to
work on practice-based theoretical models of VR in education. For example, Bambury [29]
on his website VirtualiTeach updated the Depths of VR Model, which categorizes and
differentiates between the different VR experiences available to students and educators.
The model contains four progressive levels: Perception, Interaction, Immersion, and Pres-
ence. At the Perception level, which is the basic level, learners are relatively passive and
their experience needs to be supported and framed by well-considered pedagogy. From
the Interaction level and into the Immersion level, experiences become more engaging and
student-led, and the potential for creativity and autonomy increases. Experiences at the
Presence level are characterized by the sense of “being there” and have the potential to
foster a “more visceral, emotive response” in students, which enables the deepest level of
learning.
1.2. VR Answering the Needs of Both Typical and Special Populations
The powerful theoretical backing reasonably introduces VR into pedagogical and in-
tervention fields. With the diversity of capabilities, VR can satisfy different needs of nor-
mal people and the special populations.
For normal people, VR serves as a tool for professional training and school educa-
tion. In the training for some professions such as pilots, VR-based environments simulat-
ing flying scenarios are used in place of real aircraft for lower operating costs and safety
considerations. VR technology has also developed to meet the requirements of pilot train-
ing including short lag time, rapid update rates, motion and force feedback [30]. In school
education, VR technology offers various capabilities that contribute to better learning and
education outcomes. It helps learners to visualize abstract concepts and the dynamic rela-
tionships between them and allows learners to visit and interact with people and events
that are otherwise inaccessible or unfeasible because of time, distance, cost, or safety prob-
lems [16].
For the special populations, VR can be developed into an idealized tool for interven-
tion and rehabilitation by providing a real-life but more “friendly” environment. Individ-
uals in special physical or mental conditions may have difficulty caring for themselves or
controlling their behaviors and can thus feel awkward in the face of other people. How-
ever, many of them have the need to improve social interaction abilities for their day-
today life in the real world. This dilemma can be approached through VR technology that
provides a safe and manipulable VE in which intervention can take place in a cutomized
and incremental manner at the control of therapists [22,31].
For children and adolescents with special needs, in addition to the interventional ad-
vantages [32], VR can offer substantial educational benefits. Education is always a tough
issue for atypical children since pedagogical design and frameworks for typical-develop-
ing (TD) children are usually unsuitable for them. During the learning process of children
with learning disabilities or cognitive and perceptual impairments (including ASD), ex-
perience can play a more important role because they are often described as “concrete
thinkers” who may find it difficult to comprehend abstract ideas or representations
[33,34]. Affective factors may also have a larger influence on the learning results of chil-
dren with special needs as they often suffer from emotion dysregulation and accompanied
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affective problems [35,36]. Therefore, the learning environments for children with special
needs should be experience-oriented, context-embedded, and lay great emphasis on the
affective consequences and emotional responses. VR-driven pedagogical platforms offer
the possibility of meeting these special demands. In virtual learning environments, chil-
dren with special needs are exposed to diverse concrete experiences embedded in real-
world contexts and can learn from mistakes without being discouraged or suffering the
real consequences. Moreover, VEs can enable children with special needs to experience
and explore in ways that may be impossible for them in the real world, for example, al-
lowing wheelchair users “to see how the world looks from a standing perspective” [34].
VR technology, with the above features and capabilities, then holds the promise to become
a uniquely empowering technique in special education.
1.3. Showcases of Popular VR Products
VR has been developing rather rapidly, with cutting-edge technology quickly ap-
plied to commercial production, making VR products increasingly diverse and more af-
fordable over time [37]. Currently, modern immersive VR environments are generally cre-
ated by surround-screen projection-based displays, head-mounted displays (HMDs), or
boom-mounted displays (BOOMs) [38,39].
Surround-screen projection-based displays, such as the Cave Automatic Virtual En-
vironment (CAVE) [40], usually consist of several projection walls constructed to form an
immersive environment and motion trackers that track users’ head and body gestures.
These installations allow a group of users to share virtual experiences in the same physical
environment, which is particularly useful for education in classrooms where teachers tend
to deliver VR learning materials to a class of students and keep them engaged in the im-
mersive VE. However, due to the technical complexity of constructing such displays and
the stringent requirements for the venue, it is quite difficult to apply them to large-scale
general education [41].
VR headsets are among the most common VR devices in the market, ranging from
the relatively inexpensive but limited Google Cardboard to more advanced HMDs such
as Oculus Rift, Oculus Quest, and HTC VIVE. Google Cardboard is a VR viewer that can
be purchased at moderate costs and has been favored by school teachers because it is a
stand-alone product that can be easily assembled and has a lower price [42], but its major
disadvantage is that the VE created by Google Cardboard is actually a 360° image or video,
where users cannot walk or move to approach surrounding objects. The virtual experience
provided by later HMDs is more immersive and real-world-like. Equipped with advanced
input devices (e.g., joysticks, gloves, trackers), users wearing HMDs can have a high de-
gree of autonomy in the VE where they can move around and perform various actions in
a pretty similar way as the real environment. In addition to the high level of immersion
and autonomy, HMDs also have the advantage of being portable and space-saving, which
makes them a superior option for large-scale education and training.
Another type of VR display is BOOM, a variation on HMD that is suspended from
an articulated arm measuring the head position and is held to the user's face with handles
[38]. Compared with HMDs, users do not need to support the display on his or her head
and BOOMs provide higher-quality images with shorter lag time and are not susceptible
to the influence of magnetic fields, thus enabling fast and accurate tracking [43]. BOOMs
are also very convenient for users to switch between the virtual world and the real world.
After a user releases the display, another user can observe the same images from the same
perspective. Thus BOOMs might provide some benefits for rigorously-designed experi-
ments that require participants to be exposed to exactly the same stimuli. However, they
have the disadvantage of restricted operating range due to the space taken up by the sup-
porting arms and are comparatively less widely used for education and clinical practice.
As HMDs provide adequately immersive virtual experience and are convenient to
purchase and install, they are considered to be the optimal option for large-scale education
and intervention [39] and have indeed been utilized in a considerable number of empirical
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intervention studies on people with mental health disorders (including autism) [44-47].
Some researchers pointed out that when wearing an HMD, the user’s vision is totally iso-
lated from the real surrounding world. This may raise concerns about the use of HMDs
on the ASD population [48]. Nevertheless, recent studies have obtained encouraging re-
sults that individuals with ASD adapt well to wearing HMDs and are able to comprehend,
learn, and interact in VEs [49-51]. It is also highlighted that the VR materials and contents
used for the ASD population for educational and interventional purposes should not only
be adapted to suit the immersive environment but also be combined with appropriate
pedagogical design targeting the core symptoms of ASD [39].
2. VR Technologies and ASD
2.1. Core Impairments of ASD and Its Increasing Prevalence
An impairment is considered to be core if it distinguishes the ASD population from
TD individuals and those with other developmental delays [52]. Abundant research on
ASD has identified core impairments in a variety of social aspects including social com-
munication and interaction, speech and language [53]. Social communication skills cover
a broad range of verbal and nonverbal abilities used in real-life and dynamic social inter-
action such as emotion recognition, emotion regulation, and eye-to-eye gaze. The ASD
population has difficulty understanding others’ emotions through visual and/or auditory
cues [54,55], fails to regulate emotions appropriately and effectively [35], engages less in
direct eye-to-eye contact [56] and shows atypical viewing patterns in social contexts [57].
Speech and language skills, which are crucial for successful social interaction, are also
frequently reported to be impaired in individuals with ASD. They demonstrate prosodic
deficits such as aberrant use of pitch and stress patterns [58,59] and are particularly weak
in the pragmatic use of language for communication, such as poor discourse organization
and maintaining [60], difficulty in understanding the speaker-listener relationship [61],
and inability to conform to conversational rules [62]. It is hypothesized that these prag-
matic deficits, together with emotion processing problems, are related to the fundamental
impairments in the domain of theory of mind [53,63], i.e., the cognitive ability to explain
and predict human behaviors in terms of mental states such as desire, belief, and intention
[64,65]. These core impairments in communication and language are found to be universal
in children with ASD across ages and ability levels [52,66].
Recent years have witnessed an increasing trend of prevalence of autism in the US,
China and other countries. Recent data show that one in 59 8-year-old children in the US
is diagnosed with ASD [67]. The newest result for China revealed a similar prevalence of
autism in China to western countries, at around 1% [68], and the autism prevalence in
South Korea was reported to be 2.64% (95% CI=1.91–3.37) [69]. The prevalence in various
countries and regions has shown an increasing trend over time in all age groups [70-72],
which highlights a growing need for resources to provide care for the ASD population.
The expenditure on a child with ASD, covering therapies, medical care, special education
programs, is estimated to be approximately $17,000/year more than for a child without
ASD [73], imposing a heavy economic burden on the family. The current intervention ap-
proaches, although fruitful in improving ASD individuals’ life skills, are not always avail-
able for families due to the high costs, and less expensive intervention paths for the ASD
population are required to be developed to benefit families with diverse financial capac-
ity.
2.2. Advantages of Incorporating VR in ASD Research and Therapy
Assistive and augmented technology such as VR, with the aforementioned theoreti-
cal backing and various commercial products, can offer an effective and inexpensive
means for ASD individuals to practice social skills and daily functioning both within and
outside of therapy. Given the characteristics of ASD, these capabilities are particularly
valuable for individuals on the autism spectrum.
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Treatment on VR platforms is less stressful and would be less likely to increase anx-
iety in people with ASD. Anxiety and poor stress management are common in children
and adolescents with ASD [74]. The social deficits associated with ASD can engender the
feeling of anxiety, especially in higher functioning ASD youths who are aware of their
social disability, and the overwhelming anxiety might in turn aggregate the social impair-
ments of ASD [75]. For example, social anxiety resulting from unsuccessful attempts on
communication and interaction may contribute to ASD individuals’ avoidance of social
situations and lead to further isolation from their peers [76]. This negative impact of anx-
iety that tends to accompany real-world social skill practice and may reduce the effect of
social communication intervention can be minimized through the employment of VR
technology, which allows children with ASD to practice their social skills in real-life con-
texts without fear of mistakes or rejection that they commonly encounter in real-world
face-to-face exchanges [77].
VR technology can be combined with gamified approaches to increase the motiva-
tion, attention, and focus of participants with ASD. Attention-deficit/hyperactivity disor-
der (ADHD), characterized by symptoms of inattention and overactivity, is one of the
most common comorbid disorders in people with ASD [78]. Different from TD individuals
who attend preferentially to social stimuli such as people, faces, and body movements
[79], individuals with ASD show an overall reduced social attention, which becomes
severer when the stimuli have a higher social content [80]. The inattention problem often
hinders the process of research or therapy that participants with ASD take part in, leaving
the work of researchers and clinicians floundering. This could be resolved through the
addition of a gamified VR element to current practice since the novelty of VR, together
with the playability of gamified design, could arouse among many children as well as
adults with ASD a stronger interest in the tasks they are going to accomplish, increase
their investment in the training and improve generalization [81].
Research and intervention involving VR gamified design can promote understand-
ing of and support for lower-functioning ASD populations. A majority of existing studies
and training programs, though having shown promising results, focus on ASD individu-
als with average or above-average IQ and exclude individuals with low-functioning ASD
[82], so further efforts are required exploring and supporting the ASD population at the
lower end of the IQ distribution, which demands more novel and elaborate approaches in
experimental and interventional design [55]. Research on lower-functioning individuals
can be tricky because the tasks that are manageable for TD participants or higher-func-
tioning ASD participants might imply a higher level of difficulty and demand for lower-
functioning ones due to their reduced cognitive abilities, which might result in a low task
completion rate. This poses great challenges for researchers and clinicians as they are un-
able to test whether the ability required by the specific task is intact in lower-functioning
ASDs and would then hesitate to determine whether such difficulties stem from autism
or mental retardation or both [83]. This situation can be ameliorated by the adoption of
VR technologies combined with gamified design that promotes task completion through
offering concrete, fascinating, and enjoyable dynamic stimuli. Previous attempts on using
VR games to teach emotions and on VR music education have reported the ability of chil-
dren with low-functioning autism to complete VR game-like intervention [82] and rec-
orded pretty high improvement for them [84], demonstrating that VR platforms can be
especially beneficial for low-functioning autism children.
It has been well-documented that VR technology can offer considerable educational
benefits for children and adolescents with special needs. A substantial proportion of peo-
ple suffering ASD are in childhood or adolescence. According to the fifth edition of the
DSM criteria, the age of ASD onset is “early childhood” [1] and the symptoms usually
persist through the school ages and are maintained into young adulthood [85], which ren-
ders the education of young people with ASD a primary concern and an intractable un-
dertaking. Given the nature and severity of their disability, learners with ASD require
carefully-designed individualized planning to obtain educational success, which brings
considerable challenges of including students with ASD in general education classrooms
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[86] and calls for improvement and perfection of the special education system. The edu-
cational advantages brought by VR technologies could therefore contribute greatly to the
long-term support for the ASD population and would be illuminating for educators and
policymakers working on special education services for children with ASD.
Apart from the above benefits for ASD, VR technologies also show superiority as a
tool of research and treatment. For research, VR-based experiments have enhanced eco-
logical validity, which is increasingly valued in the assessment of neuropsychological re-
search, especially in the field of ASD [87]. Ecological validity, defined as the degree to
which task performance corresponds to real-world performance [88] or the degree to
which task performance predicts problems in real-life settings [89], has been viewed, to
some extent, to conflict with the maintaining of experimental control [90]. Researchers
supporting naturalistic approaches hold that many psychological assessments that use
simple and static stimuli are ecologically invalid and are unable to generalize beyond re-
stricted laboratory settings [91] while those emphasizing precise laboratory-based control
argue that the ecological research approach lacks experimental control and the internal
validity that are needed for scientific progress [92]. The tension between experimental
control and ecological validity could be alleviated through the integration of VR, which
allows precise presentation and control of dynamic perceptual stimuli in ecologically
valid scenarios, thus increasing the generalizability of the findings whilst maintaining the
same level of control as laboratory-based experiments.
Intervention programs employing VR techniques allow repeated practice and expo-
sure, which is a key element in treatment [44]. In interventions such as social communica-
tion training, it is rare that participants successfully acquire the social interaction skill after
practicing it only once. Compared to other therapeutic tools that might instruct partici-
pants to learn and respond in a rote manner, VR interventions provide the opportunity
for repeated practice in dynamic social exchanges [93] and help participants learn by ex-
periencing instead of memorizing. Additionally, on VR platforms, tasks and stimuli can
be presented repeatedly and consistently without fatigue [94], avoiding the problem that
usually accompanies task repetition by human tutors/instructors [95].
2.3. Potentials of VR for Investigating Social Interaction
Among possible applications, the one that receives particular attention from ASD re-
searchers and therapists is the VR-based investigation of social communication and inter-
action, where ASD individuals tend to be especially impaired. VR offers great potential
for social communication research and intervention as it can provide customized authen-
tic scenarios and interlocutors, which are essential in real-life social communication, as
well as the sense of being present at the scene of communication.
The social scenarios and contexts replicated in VEs can be carefully designed and
controlled at the will of researchers and therapists to create whatever type of environment
they want. For various research purposes, features of the real world can either be omitted,
enhanced or diminished, social relationships can be emphasized or modified, and the
qualities and quantities of surrounding objects can be highlighted or weakened, increased
or reduced [34]. The possible social scenarios that can be created through VR are arguably
unlimited [96], including social introductions, initiating conversation, meeting
strangers/friends, negotiating with a salesman, job interview, working with co-workers
and managing conflict [44].
Virtual humanoid representations of people involved in the social scenarios, referred
to as “avatars”, can be designed to serve as communicators that carry out social commu-
nication with the user and give him or her hints on the communicational rules, and as
facilitators that offer the user positive reinforcement upon his or her successful attempt to
communicate or encourage further practice when the user makes mistakes [97]. The ava-
tars can also be manipulated according to the requirements of researchers and clinicians;
for example, the clinician’s voice can be morphed by software to sound like a young boy
in order to match the avatar’s demographics [44]. Moreover, with the aid of artificial
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intelligence (AI), completely virtual characters can be created without the need for a ther-
apist.
The sense of being present, which is positively correlated with the level of immersion
[98], also contributes greatly to the potential of using VR for the investigation of social
communication and interaction. Practical application is indispensable for the training of
social communication skills, with the benefits of intervention usually reduced when ex-
posure to real-world social interactions is absent or inadequate [99]. Individuals with au-
tism have reported a desire for more real-world practice after learning social communica-
tion skills in clinical intervention because they sometimes find it difficult to understand a
social phenomenon until they see or experience it in a real-world setting [99]. Practicing a
learned skill in a real-world context and being successful in that situation would also build
confidence in people with ASD and help reduce their social anxiety [99]. Modern VR tech-
nologies and products including surround-screen projection-based displays like the
CAVE and HMDs like Oculus Rift, with multisensory (e.g., visual, auditory, and tactile)
congruent cues in the VEs further enhancing the sense of presence [98], all enable a fairly
high level of immersion, rendering them viable tools for study and training of social com-
munication skills.
3. Recent Applications of VR Technologies to ASD Assessment and Intervention: Evi-
dence-based Practice
VR technology gains theoretical support from rehabilitation and pedagogical theo-
ries with powerful and diverse capabilities. When it is instantiated in accessible and af-
fordable commercial products, VR is a superior alternative technique for ASD research
and therapy and a promising methodological tool to investigate and improve social com-
munication and interaction skills. The promising prospect of technology-driven pedagog-
ical and intervention platforms has prompted researchers to integrate VR technologies
into ASD assessment and intervention, with success, especially in terms of social commu-
nication deficits. This section will illustrate recent evidence-based applications of VR tech-
nologies to ASD research and treatment, with a primary focus on the social aspects in-
cluding social functioning, emotion recognition, and speech and language.
3.1. Social Functioning
Problems in social functioning (e.g., unemployment, impaired social skills, low social
motivation, high social anxiety, social avoidance), are common in the ASD population
[100,101]. There has been some clinical evidence that VR-based systems can have an in-
creasingly positive impact on the social functioning of individuals with ASD [102]. With
the aid of assistive technology, especially VR, participants with ASD showed improve-
ments in social task performance [103-105], communication ability [106], sensitivity to so-
cial contingencies (i.e., the other’s responsiveness to one’s own behavior) [107], social com-
petences and executive functions [108]. There is also evidence that in real-time, computer-
mediated social space, people with ASD could perform social tasks equally well as con-
trols, indicating that the use of VR interfaces could help compensate for the social disabil-
ities of people with ASD [107].
In recent years, investigators have been developing VR agents, systems, and plat-
forms to offer social functioning training to people with autism. For example, Bernardini,
et al. [109] created an autonomous planning-based agent called Andy that inhabits a VE
designed for real-world use at home and in schools. This agent is the main component of
the Intelligent Engine of ECHOES, a serious game built to help young children with ASD
acquire social communication skills [110]. In the game-like intervention program, Andy
the agent is always positive, motivating, and supportive and plays a diversity of roles
including a tutor who delivers visual and organizational support for ASD children, and a
peer who provides them with customized interpersonal support and exposes them to pos-
itive interactions. The system together with the agent has been deployed in five schools in
the UK and was proved to be effective in improving social behaviors of ASD children in
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an eight-week intervention study involving 19 children with autism [109]. Autonomous
virtual agents such as Andy could contribute to the intensive one-on-one support needed
by ASD children, easing the demand for such support from clinicians and parents [109].
Considerable efforts have been made to alleviate the employment problem of indi-
viduals with ASD through VR-driven intervention systems. Burke, et al. [111] created a
Virtual Interactive Training Agent (ViTA) system to offer practice in job interview skills
required in interview conditions at various difficulty levels. The system includes six vir-
tual human agents of varying ages and ethnic backgrounds, who can exhibit soft-touch,
neutral, or hostile dispositions when asking 10 to 12 interview questions, and seven situ-
ational contexts such as business office, hotel lobby, and warehouse breakroom, according
to participants’ specific employment interests. In a preliminary study, the ViTA system
has enhanced job interviewing skills in 32 participants with autism and developmental
disabilities, with their face-to-face interview outcomes improved significantly after train-
ing, demonstrating its effectiveness as a tool for preparing young adults with autism for
employment interviews [111].
Similarly, Smith, et al. [112] developed Virtual Reality Job Interview Training (VR-
JIT), a program providing VR-simulated repetitive job interviews grounded on hierar-
chical learning, to help facilitate job interview skill training for people with neuropsychi-
atric disorders. Targeting eight job-interview performance domains such as conveying
oneself as a hard worker and sounding easy to work with, the system provides repeatable
VR interviews for trainees to interact with a virtual human resources representative, offers
them instant feedback to improve their responses, returns scores on key dimensions of
performance, and allows review of interview responses. The feasibility and efficacy of VR-
JIT have been assessed in a single-blinded randomized controlled trial involving 26 par-
ticipants with autism, the results of which suggested that finding it easy to use and enjoy-
able, individuals with ASD showed improvements in interviewing skills after receiving
training on the VR-JIT system [113] and achieved better vocational outcomes [114].
Another VR-enabled program targeting the employment issue was designed by
Strickland, et al. [115], called the JobTIPS program, which offers five sections to guide
trainees with ASD through the process of determining career interests, finding a job, get-
ting a job, and keeping a job, and also provides other employment-related topics like leav-
ing a job. Results of a randomized controlled study on 22 participants with autism re-
vealed that ASD individuals completing the JobTIPS employment program showed en-
hanced job interviewing skills and significantly more effective verbal content skills. Nev-
ertheless, the author pointed out that their program was more effective in teaching “con-
tent” (i.e., producing appropriate verbal responses to the interview questions) rather than
“delivery” skills (e.g., posture, eye contact).
Kandalaft, et al. [44] focused on more comprehensive aspects of social functioning
and developed the Virtual Reality Social Cognition Training (VR-SCT) intervention, a
semi-structured, manualized intervention that offers VR-based dynamic practice of mean-
ingful social scenarios for young adults to improve social cognition, social functioning,
and social skills. Scenarios in various social contexts were constructed to simulate com-
mon real-life social situations including meeting new people, negotiating financial or so-
cial decisions, dealing with a roommate conflict, and interviewing for a job. A feasibility
study involving eight young adults with ASD [44] and another involving 30 ASD children
and adolescents ages 7-16 years [93] were conducted to examine the effectiveness of VR-
SCT and found that after 10-session VR-SCT intervention, there were significant increases
in ASD participants’ social and occupational functioning in real life as well as a series of
social cognition measures, demonstrating positive impacts of the VR-enabled social skill
training program on a wide range of social functioning and social abilities in individuals
with ASD across ages. The treatment effectiveness has been further verified by recent in-
vestigation on the neural mechanisms of response to intervention in participants with au-
tism receiving VR-SCT, which discovered that such interventions are not only useful in
improving social cognition and social skills in individuals with ASD, but also contribute
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to the strengthening of underlying brain networks that support their higher social func-
tioning capacity [116].
In addition to the above VR social skill training systems, many other VR-driven plat-
forms have also proved to be efficacious in enhancing social functioning and social un-
derstanding in ASD, such as Virtual Environment for Social Information Processing
(VESIP) [117] and collaborative virtual environment (CVE)-based social interaction plat-
forms including iSocial [118] and CVE-based puzzle games [119-121].
3.2. Emotion Recognition
The difficulty in recognizing and understanding emotional expressions through mul-
tiple cues is one of the fundamental social impairments in the ASD population [122,123].
Children with ASD often show an atypical emotional development from TD children,
manifested as a lack of empathy with other people and failure to react emotionally to other
people's states of mind [124]. Learning emotion recognition in VEs could remove such
emotional barriers and obstacles for the ASD population, as VR training programs have
been proved to be particularly helpful regarding emotion recognition improvement in in-
dividuals with ASD. For example, previous studies have reported enhanced behavioral
performance [44] as well as neural predictors of change [116,125] in emotion recognition
and theory of mind in participants with ASD after they completed the VR-SCT program.
Similar results were obtained by Ke and Im [126] who observed a consistent and obvious
increase in ASD children’s perception of emotion from facial expression and posture cues
after a VR-based social interaction program and Ip, et al. [127] who documented signifi-
cant improvements in emotion recognition in over 100 school-aged ASD children after
training completion in a CAVE-like immersive VR-enabled system.
In terms of emotion recognition, the level of immersion in the VE could influence the
intervention effect. Lorenzo, et al. [124] conducted a randomized controlled study in
which they designed an immersive virtual reality system (IVRS) to train and improve the
emotional skills of 40 children with ASD. Their results revealed that compared with the
use of desktop VR applications, participants showed more appropriate emotional behav-
iors in the immersive VE and there was a significant improvement in their emotional com-
petences after IVRS training. This finding is corroborated by the results obtained by
Schwarze, et al. [128] who found that VR settings are motivational and useful for individ-
uals with ASD to learn emotion recognition, especially under the condition that similar
traditional approaches were transferred to a virtual context, e.g., virtual emotion cards.
Furthermore, owing to the high immersion of VR-HMD technologies that provide an en-
closing, three-dimensional and 360-degree environment for emotion recognition learning,
children with ASD were observed to start behaving in an “extroverted” way in their in-
teraction and learning activities [128].
A few recent studies have been attempting to integrate VR technology with dynamic
psychophysiological signals to improve intervention approaches regarding emotion
recognition. Lahiri, et al. [56] developed a VR-based dynamic eye-tracking system called
Virtual Interactive system with Gaze-sensitive Adaptive Response Technology (VIGART)
that can deliver individualized feedback according to the user’s dynamic gaze patterns
during emotion recognition training. The system contained five social communication sce-
narios where the avatars narrated their experience on various topics such as food, sports,
travel, etc. Results of a usability study with six ASD adolescents confirmed that the
VIGART can record dynamically eye physiological indexes, enabling objective measures
of the user’s emotion recognition capability that could in turn guide the refinement of
intervention strategies [56].
Modugumudi, et al. [129] conducted an electrophysiological study of two groups of
autistic children (ten in each) receiving an intervention program with and without CVEs
as assistive technology to see whether children with autism could recognize basic emo-
tions effectively in CVEs. The results showed that an emphasized early emotion expres-
sion positivity component at around 120 ms latency was identified for the CVE trained
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group, which clearly distinguished it from the trained-without-CVE group, indicating
that children with autism had a significant improvement in emotion recognition owing to
the CVE-based intervention.
Incorporating both eye physiological indexes and electrophysiological signals,
Bekele, et al. [130] designed and developed the Multimodal Adaptive Social Interaction in
VR (MASI-VR) system that facilitates individualization and adaptation for ASD emotion
recognition intervention. The system presents controlled facial emotional expressions
within conversational social contexts, tracking eye gaze as well as collecting in a synchro-
nous manner electroencephalography (EEG) data associated with emotion recognition
while the users are receiving emotion recognition training and performing the emotion
recognition tasks pre- and post-training. The viability and efficacy of this system have
been verified through a randomized controlled study with 12 children with ASD, sup-
porting the idea of using task performance and eye gaze, and possibly other psychophys-
iological data, to enable real-time adaptation of ASD intervention in VR-based training
systems [130].
Besides the above breakthroughs in terms of VR-enabled emotion recognition train-
ing, researchers have also sought assistance from VR technology to enhance the under-
standing of how individuals with ASD perceive and handle emotional expressions. For
example, Kim, et al. [131] employed a novel measure called the VR emotion sensitivity
test (V-REST) [132] to examine emotion perception and interpersonal distance in ASD
with the aid of a joystick. While identifying the emotions expressed by virtual avatars,
participants could position themselves close to or away from the avatars through the joy-
stick. The study discovered that compared to TD children, children with ASD approached
positive happy expressions significantly less, which suggests that children with autism
might display atypical social-approach motivation or are less sensitive to the reward of
positive socio-emotional events [131]. These results call for revision and updating of the
social-motivation model of ASD [133,134].
3.3. Speech and Language Training
The ASD populations often have delayed or impaired speech and language abilities,
affecting both production and perception, which adds to their communication barriers
[135]. Compared to the substantial efforts on VR-based training of social functioning and
emotion recognition, less attention has been paid to applying this technology to speech
and language therapy in ASD. The majority of the existing research and practice focuses
on teaching discrete language components such as vocabulary, grammar, semantics, and
pronunciation, with the pedagogical and interventional platforms still limited to non-im-
mersive VEs such as desktop VE and augmented reality (AR).
A computer-based language-tutorial program that has been inspiring for later at-
tempts in this area is the virtual talking head called Baldi, developed by Bosseler and
Massaro to train vocabulary and grammar knowledge for ASD children [136]. Imple-
mented in a Language Wizard, Baldi allows easy creation and presentation of language
lessons concerning identifying pictures and producing spoken words. An evaluation
study was conducted to assess the effectiveness of this computer-animated tutor in vocab-
ulary training and indicated that with the aid of the virtual agent, children with autism
were able to learn language skills and could transfer the learned vocabulary in a new en-
vironment outside of the program [136].
Saadatzi, et al. [137] also developed a tutoring system targeting sight word instruc-
tion by combining VR technology and social robotics. This system featured a small-group
classroom environment with a virtual agent as the teacher, and a humanoid robot as the
peer, to facilitate observational learning, i.e., learning by watching others and imitating
[138]. The effectiveness of the tutoring system was evaluated through an intervention
study involving three participants with ASD who acquired, maintained, and generalized
all the words that had been explicitly taught to them by the system and made fewer errors
on the words that were also taught to their robot peer.
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Nubia, et al. [139] resorted to AR to design and develop a mobile application that
could serve as an alternative tool for semantic therapies to help improve semantic word
knowledge in children with ASD. This application could stimulate oral and expressive
language production in children with ASD by playing onomatopoeias or the sounds as-
sociated with animals and objects. Compared with the conventional therapy, intervention
using the AR mobile application led to an increase, which was confirmed by speech ther-
apists, in the verbal language produced by the ASD participants [139].
Apart from vocabulary, grammar, and semantics, the positive impacts of virtual ele-
ments and techniques on speech and language training in ASD have also been extended
to the domain of pronunciation. Chen, et al. [140], incorporating the ideas of imitative
learning [141], designed a 3-D virtual imitation intervention system to provide audiovis-
ual pronunciation training for children with ASD. The computer-assisted 3-D virtual pro-
nunciation tutor was able to present, in a multimodal and real-data-driven manner, the
places and manners of Mandarin phoneme articulation and has been proved to efficiently
enhance the accuracy of Mandarin consonant and vowel pronunciation in low-function-
ing children with ASD [140].
4. Limitations and Disputes
While the application of VR to ASD research and intervention holds significant po-
tential and considerable achievements have been recorded in terms of improving ASD
individuals’ social communication abilities, there are technology- and design-related lim-
itations that remain to be addressed as well as controversial issues that must be taken into
consideration in the design of future studies.
4.1. Limitations in Technology and Design
Though VR technology has improved tremendously in recent years, certain technical
imperfections still exist such as graphic update rate, field of view (for HMDs), lags be-
tween head tracking and visualization [142,143]. Besides these limitations, a particular
technical challenge for VR applications is the simulation of behaviorally realistic virtual
avatars. Current VR technology has been capable of creating vivid and lifelike avatars but
they are inevitably different from real humans in either appearance or behavior. This
would to some extent influence the responses of participants [144] in that if they are con-
stantly reminded that the people they encounter are not real by the not-authentic-enough
behaviors of avatars, the way they behave and respond in virtual worlds would diverge
from that in the real world and could thus not be used as the indicator of their abilities.
For example, in the study conducted by Parsons et al., one participant reported that he
did not walk across the grass of a garden in the VE because that could make his shoes
muddy; however, he walked between two people having a conversation in the cafeteria
because they “weren't real” and “it didn't matter” [145]. Another technological limitation
is the restricted range (usually a few square meters) within which participants have to use
the interaction and tracking devices in order to maintain good connection and interaction
with the VE. These technical restrictions might limit the level of immersion provided by a
VR system and result in a lower experience of presence [146].
In addition to the above technical limitations, inadequacies exist regarding learning
content and activity design. Despite the promising results of current successful attempts
in VR-based training in ASD, the VR learning content used in many existing studies fo-
cused on too confined scenarios and situations [147] and the skills being taught were often
procedural and strongly rule-based, with inadequate emphasis laid on the skills required
in relatively unpredictable social situations [9]. Another problem with the content and
design is that a certain number of training activities in current VR intervention are ill-
devised, including only repeated and tedium practice that is likely to bore ASD children
after the initial novelty wears off. One possible solution to this issue is to add recreation
value to the VR training systems by borrowing serious game design concepts [148] from
the entertainment sector. More enjoyable content and increasingly engaging activities
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would also attract more participants to the training systems, which can prevent the draw-
back of inadequate statistical power caused by the small number of participants in most
previous feasibility and validity studies [149], helping researchers draw more convincing
conclusions on the effectiveness of VR-based intervention systems.
4.2. Current Disputes
The disputes over the application of VR technology to ASD research and therapy
cover mainly three aspects, i.e., challenges to the veridicality assumption, safety concerns,
and ethical considerations. Some researchers have queried the authenticity and veridical-
ity of VEs that have provided a strong argument for the integration of VR-based design
into various educational and health fields [144]. The potential and strengths of using VR
to investigate social communication and interactions are grounded on the fundamental
belief that VEs provide realistic and authentic experiences that mirror real-world behav-
iors and responses. However, this assumption may be open to question because the de-
gree of perceived realism in VEs can be affected by many factors including the features of
VEs (e.g., the degree of autonomy allowed in the VEs, how real the avatars and the sce-
narios are [150], the way of interaction between users and systems [151], whether the av-
atars are controlled by humans or computers [152]) and the background characteristics of
users (e.g., whether users have postural instability, whether they are susceptible to motion
sickness [153]). The VR technologies adopted by many existing studies, such as AR and
desktop VR, are actually non-immersive and provide rather limited autonomy. Although
they have taken a step further compared to the traditional simple and static stimuli, it is
still debatable to what extent the responses recorded in these VEs are generalizable to real-
world responding and interpretation [144].
Moreover, even for the highly immersive VEs created by HMDs or CAVE-like sys-
tems, which are among the most advanced VR techniques so far, technological limitations
that would influence the perceived realism of VR experience and the transfer of learning
to real-world contexts still exist, which leaves plenty of room and possibilities for future
improvement. For example, Parsons [144] suggested that there are at least two disparate
directions for future efforts to move the field forward, i.e., to increase the realism of VEs
and pursue extreme veridicality of VR technology or to diverge from the pursuit of pure
veridicality and consider more the needs and preferences of the users. Within the scope
of ASD research and intervention, the latter perspective would lay more emphasis on
questions including the following. For people with ASD and their families, what elements
in VEs are the most important and would be particularly useful to support and enhance
their communication and learning? Do the degree of realism and the veridicality linearly
correlate with the effectiveness of VR-based ASD training systems or is there a breakpoint
at which the effectiveness plateaus? If the breakpoint exists, what degree of authenticity
is optimal so that people with ASD and their families could benefit the most from VR
technology without spending too much time and effort seeking cutting-edge equipment
or waiting for further technology development. There is a need to inquire into these as-
pects directly and in more detail in order to really understand how VR technology can
positively influence the ASD population’s learning, well-being, and life quality.
Safety risks, both physically and psychologically, might be associated with the use
of VR. A common physical safety concern associated with VR experience is cybersickness,
which can cause fatigue, malaise, and dizziness, or even elicit a series of symptoms such
as eye strain, nausea, and bodily disorientation [154,155]. In addition to the possible phys-
ical discomfort, some researchers pointed out the potential psychological safety risks ac-
companying but not unique to the use of VR, suggesting that similar to the problems doc-
umented in people engaging in excessive use of video games, extended and continuous
use of VR might be linked with certain mental uneasiness [156]. These safety risks do have
led to some disputes over the use of VR in the ASD population, but rather than discour-
aging its application, we could instead carefully consider and control these risks in the
design of future studies. For example, to minimize the consequences of cybersickness
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(including symptoms of nausea, vomiting, drowsiness, headache, loss of balance and
problematic eye-hand coordination), risk assessment based on predictive questionnaires
such as the Motion Sickness Susceptibility Questionnaire (MSSQ-Short) [157] ought to be
conducted prior to training or experiments and immediate reports of discomfort as well
as timely support from therapists are necessary during the initial use of VR. For ASD
trainees who have no previous exposure to VR, transition periods could be arranged to
help them gradually adapt to VEs. As for the concern about psychological safety, the du-
ration of exposure to VR should be strictly controlled in both research and therapy ses-
sions to prevent the negative impact of excessive and inappropriate use from overshad-
owing the benefits of this technology.
Apart from the challenges to veridicality and the safety concerns associated with VR,
ethical considerations also provoke extensive discussion, among which the most debated
one might be the question of privacy and confidentiality during data collection [156]. In
the process of VR-enabled research and intervention, eye-movement patterns, facial ex-
pressions, and body responses and reflexes, which constitute one’s distinct “kinematic
fingerprint” [155], would be recorded. Given the commercial nature of many VR products,
this personal information of participants could be accessed by the companies that deliver
the VR software who tend to state in the privacy policy that user data may be collected.
Therefore, researchers and therapists using VR technologies need to provide participants
clearly-stated informed consent forms to ensure that they are aware of and consent to the
data collection issue before participation.
5. Future Directions
Since the first employment of VR technologies on the ASD population in the 1990s
[48], there has been a significant increase over the past decades in the number of studies
using VR for ASD research and intervention [158]. The literature has seen increasing
recognition of the benefits and potentials of VR to facilitate learning, especially in social
environments in individuals with autism. But there is still much work that remains to be
done in this research area. Future efforts can be directed towards application expansion
and improvement, technology enhancement, and brain-based research and theoretical
model development. The contributions of these basic and applied studies would be at
least three-fold: benefiting the ASD population, reducing the workload of therapists, and
facilitating the advancement of the VR technology as well as theoretical modeling of VR
application with beneficial social and cultural consequences.
5.1. Application Expansion and Improvement
Existing VR-based training systems and platforms have paid much attention to im-
proving ASD individuals’ performance in social functioning, emotion processing, and
speech and language, but a majority of them treated these socially important aspects in-
dependently and designed training programs that centered around one specific respect;
few have taken an integrated view of these skills to systematically enhance social commu-
nication in ASD. Within each aspect, the research was also discrete and divided. For ex-
ample, the VR-based intervention programs and systems for speech and language training
have focused on grammar and vocabulary, or semantics, or pronunciation, but rarely at-
tempted to integrate these components of language communication skills in one training
system. Many training programs, though proved to be effective in improving ASD train-
ees’ specific skills, often meet with limited success in enhancing the overall social perfor-
mance of the ASD population [159-161]. One probable explanation for this problem is that
intervention and training that involves correlates of different target skill domains is often
missing from the research and treatment efforts in ASD, and even though these correlates
are included in some programs, they are not always trained systematically [160]. The
“transactive” relationships between different behavioral domains [162] determine that im-
provements in one domain contribute to progress in other domains and delay in any one
could affect development in the others [163,164]. For example, VR training programs
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aiming to improve employment-related skills in ASD may lead to better use of strategies
by participants with ASD during job seeking, but their actual overall performance might
improve little due to the remaining weakness in emotion perception or speech production
and understanding [115]. Effective intervention in social communication in ASD thus not
only requires training in specific social aspects including social functioning, emotion pro-
cessing, and speech and language, but also calls for integrative efforts to resolve the diffi-
culties that correlate these domains.
To systematically improve social communication performance that involves various
social domains, future VR-based ASD intervention systems can lay more emphasis on the
training and learning of prosody, which plays a vital role in a range of communicative
functions (linguistic/grammatical, pragmatic, affective, etc.) [165] and the correct use of
which, promoting peer interaction and socialization, is fundamental for both personal de-
velopment and social integration of individuals with ASD [166]. Prosody functions at
three major levels (not mutually exclusive) to enable smooth social communication: gram-
matical prosody is crucial for the expression of semantic meaning (e.g., resolving semantic
ambiguity); pragmatic prosody conveys the speaker’s intentions (e.g., emphasizing certain
information); affective prosody implies the speaker’s emotions or affective states (e.g., feel-
ing happy or sad, relaxed or anxious) [167]. These functions cover a wide range of both
linguistic and socio-affective domains, which means that atypical use and understanding
of prosody would greatly undermine efficient social interaction and language communi-
cation. More research and intervention studies are thus recommended to combine VR
technology with integrated training in prosody, both linguistic and affective, and its com-
bination with grammar, semantics and pragmatics to improve socio-affective and linguis-
tic skills and ultimately enhance overall social communication in ASD.
Since a large proportion of ASD individuals are in childhood or of school age, ideas
in the field of education would be helpful for alleviating ASD core symptoms over the
course of development. Existing research on VR-based ASD training has benefited much
from pedagogical theories [137] and future exploration could continue integrating philos-
ophy in education and learning to develop better VR-based training programs for ASD.
For example, Iovannone, et al. [168] proposed six essential components to be included in
an effective educational program for ASD students, i.e., individualized supports and ser-
vices for students and families, specialized curriculum content, systematic instruction,
comprehensible and/or structured environments, a functional approach to problem be-
haviors, and family involvement. These components, especially the first two, could be
well-incorporated into VR-driven training programs by providing language- and cultural-
specific individualized training packages to enable more effective targeted intervention.
Future design of VR training systems, especially for social communication training,
needs to show more consideration for users’ language and cultural backgrounds. For ex-
ample, it has been hypothesized that prosodic deficits in the ASD population reside pri-
marily in the pragmatic and affective aspects, with grammatical aspects relatively spared
[167]. However, this conclusion was drawn mainly based on data collected from ASD in-
dividuals speaking English or other non-tonal languages where syllable-level prosodic
variations (or lexical tones) do not distinguish lexical meaning. For tonal language speak-
ers with autism, atypical perception of lexical tones has been observed [169], which indi-
cates impairment in grammatical-prosodic processing in addition to their pragmatic dif-
ficulties [170]. Therefore, whether grammatical functions of prosody are impaired among
the ASD population is disputed and is likely to differ due to the influence of language
backgrounds, so the design of future VR-based practice should take into consideration
this language-specific problem and be tailored to ASD individuals according to their lan-
guage backgrounds. Similarly, cultural factors should also be taken into account in future
exploration in this area as many social behaviors are culture-dependent. For instance,
training on the social skills of people with ASD usually encourages them to make eye
contact with the communication partner. However, looking the elders directly in the eye
is regarded as disrespectful in some countries such as India and Bangladesh [171]. It is
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thus crucial to design the training scenarios and activities with an eye to the cultural back-
grounds of the ASD users.
The heterogeneity within the autism spectrum implies that even if with the same lan-
guage and cultural background, each individual with ASD is still unique and a specific
intervention or treatment may not always be the best for the whole population [172]. The
effectiveness of the intervention depends largely on how accurately it targets the specific
vulnerabilities of the ASD participant, so it is necessary to offer individualized VR-based
training and intervention that is able to cater for the preferences of each ASD individual.
In conventional intervention, therapists tend to adjust the intervention paradigm accord-
ing to the ASD individual’s specific cognitive and behavioral conditions [97]. Future de-
velopment of VR-based training systems for ASD should also take into consideration the
adaptation of skill training to the user’s specific needs. For example, research on emotion
processing in ASD has produced very mixed results, with disagreement persisting over
whether it is impaired in ASD individuals [54]. The heterogeneous performance across
tasks and across individuals (even in one single study) suggests that emotion processing
may not be universally impaired in ASD and the degree of deficits may also vary across
individuals [173]. VR-based training systems could then incorporate AI assessment pro-
cedures to automatically examine the degree of certain deficits in the specific user and
adjust the subsequent training plan according to the assessment results. For instance, for
users with ASD who are assessed to have particular difficulty perceiving and understand-
ing certain emotions, the VR training system may correspondingly adjust the proportion
of training in emotion processing and provide targeted practice to promote optimum
learning of relevant social skills.
For the same person, the condition may also change over time. In the short term, the
performance during one intervention session would fluctuate and calls for dynamic and
real-time adaptation. In the long term, the variation in the different stages of development
also requires the intervention objectives and strategies to be tuned accordingly. For exam-
ple, school-aged autistic children may need more instruction in coping with bullying
whereas young adults with ASD would desire extra training in employment skills such
as finding and keeping a job. Besides the change in intervention-related needs, the cogni-
tive level and the language ability of the ASD user might also improve over the course of
development [174,175]. Then, in order for the intervention to be continuously effective,
the learning content, the language material and the activity design in the VR training sys-
tems should be able to be updated along with the developmental change of the ASD user.
5.2. Technology Enhancement
As illustrated in the previous section, there is much room for future improvements
to VR-driven training systems for ASD. Potential breakthroughs in all these directions
require corresponding enhancement of VR technology to facilitate the application expan-
sion. For example, researchers and engineers on VR technology development can investi-
gate how to combine VR technologies with AI and machine-learning techniques to pro-
mote customized intervention and provide tailored support. Automatic recognition and
assessment technology including automatic speech recognition and evaluation [176,177],
automatic assessment of cognitive and emotional states [178] need to be embedded into
the VR training systems to measure and track users’ abilities and states and deliver im-
mediate and timely feedback prior to, during, and after training. The incorporation of ac-
curate, intelligent, and efficient automatic evaluation techniques can greatly ease the
workload of speech-language and cognitive-behavioral therapists and more importantly,
offer much-needed assessment and intervention services for the ASD population living in
less developed regions that lack trained and qualified therapists.
Future exploration may expand the functionality of VR so that it can be part of big
data that promote worldwide collaboration on autism research and facilitate data-driven
discoveries. The ideal big data for autism research should be both “broad” and “deep”.
Broad data is characteristic of large sample sizes whereas deep data involve analysis of
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multiple levels of information collected on the same individuals including behavior and
development, neural systems, and outcomes of clinical treatment [179]. VR training plat-
forms can be a perfect channel for gathering such “broad” and “deep” big data owing to
their capability to collect dynamic and detailed behavioral and neural data at various
stages of training and intervention. Future VR training systems can be improved to not
only enable recording of the multi-level data of ASD trainees who have given informed
consent, but also allow uploading of these data onto cloud storage space as well as later
downloading of them by authorized users. Furthermore, researchers can draw from tech-
niques and strategies that are commonly employed in designing, building, and managing
a database and work out efficient ways of VR data pooling and collating to develop secure
and searchable VR-based multi-level ASD data repositories for research purposes. Such
databases can be very helpful in providing comparison and reference for ASD assessment
and diagnosis as well as furthering our understanding of heterogeneity in autism [179].
Another direction of function expansion for future VR-based ASD training systems
is to provide ASD individuals and therapists with personal data banks for monitoring
progress and informing subsequent intervention decisions. The training systems can be
enhanced to regularly create and push visualized personal reports that document the ASD
user’s progress and status quo; for example, how much the ASD trainee has progressed
in certain skills since the last time, what are the skills he or she has improved the most,
which aspects require increasing practice in later training. This kind of feedback would
be encouraging for ASD individuals and their families by assuring them that conditions
are indeed improving and they should persevere with the training. A more detailed per-
sonal data bank would also be useful for therapists as information on the pretreatment
characteristics is often needed for them to individualize the following intervention plan
[97].
5.3. Brain-based Research and Theoretical Model Development
Existing evaluation of the treatment effectiveness of VR-based training in ASD relies
primarily on behaviors such as improved performance on tasks or tests, with limited evi-
dence for the neural changes underlying these behavioral gains. Although a few pioneer-
ing studies have attempted to examine how therapeutic responses to VR training reflect
brain changes in ASD [116], it remains to be answered whether VR can support the devel-
opment of brain networks of ASD individuals. Brain-based research is crucial for VR ap-
plication to ASD because brain data is an indispensable level of “deep” big data [179] and
plays a crucial role in the substantiation, revision and updating of theoretical models in
ASD research [180]. Future investigation on VR integration into ASD assessment and in-
tervention is thus recommended to utilize neurophysiological and neuroimaging tech-
niques to track and measure brain responses of ASD participants before, during, and after
VR training to evaluate the efficacy and limitations of multi-modal VR-based training
from the perspective of brain plasticity and to elucidate the neural underpinnings of be-
havioral improvements both at the group level and the individual level.
Data obtained from brain-based research is also useful for theoretical modeling of
VR technology and application. Existing theoretical models of VR technology in ASD
mostly focus on multiple levels of cognitive and behavioral enhancement [8] and few of
them have touched upon how the brain or neural mechanisms of ASD individuals would
evolve due to the exposure to VR training. Future efforts could extend the existing models
by linking brain activities and changes with behavioral improvements at multiple levels
or developing new models that expound the influence of VR training on brain changes in
ASD individuals at different developmental stages. In particular, specific concepts and
issues such as the understanding of self vs. other and the multi-channel and multimodal
nature of social signal processing that can inform the biological, psychological and neuro-
physiological underpinnings of social communication need to be clarified. Such social
neuroscience models incorporating both behavioral and neural aspects will provide in-
sightful guidance for the designing, developing and evaluating of VR-based ASD training
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 3 February 2022 doi:10.20944/preprints202202.0056.v1
platforms that can be potentially added to traditional behavioral therapies and educa-
tional settings with great social and cultural consequences.
Author Contributions: Conceptualization, Y.Z.; writing—original draft preparation, M.Z.; writ-
ing—review and editing, H.D. and Y.Z. All authors have read and agreed to the published version
of the manuscript.
Funding: This work was supported by grants from the Major Project of National Social Science
Foundation of China (18ZDA293).
Institutional Review Board Statement: Not applicable.
Informed Consent Statement: Not applicable.
Data Availability Statement: Not applicable.
Conflicts of Interest: The authors declare no conflict of interest.
References
1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders (5th ed.); American Psychiatric Publishing:
2013.
2. Howlin, P. Autism: Preparing for adulthood; Routledge: London, 1997.
3. Bekele, E.; Zheng, Z.; Swanson, A.; Crittendon, J.; Warren, Z.; Sarkar, N. Understanding how adolescents with autism respond
to facial expressions in virtual reality environments. IEEE Transactions on Visualization and Computer Graphics 2013, 19, 711-720,
doi:10.1109/TVCG.2013.42.
4. Orlosky, J.; Itoh, Y.; Ranchet, M.; Kiyokawa, K.; Morgan, J.; Devos, H. Emulation of physician tasks in eye-tracked virtual reality
for remote diagnosis of neurodegenerative disease. IEEE Transactions on Visualization and Computer Graphics 2017, 23, 1302-1311,
doi:10.1109/TVCG.2017.2657018.
5. Bird, M.-L.; Cannell, J.; Jovic, E.; Rathjen, A.; Lane, K.; Tyson, A.; Callisaya, M.; Smith, S. A randomized controlled trial
investigating the efficacy of virtual reality in inpatient stroke rehabilitation. Arch. Phys. Med. Rehabil. 2017, 98, e27,
doi:10.1016/j.apmr.2017.08.084.
6. Pulijala, Y.; Ma, M.; Pears, M.; Peebles, D.; Ayoub, A. Effectiveness of immersive virtual reality in surgical training—a
randomized control trial. Journal of Oral and Maxillofacial Surgery 2018, 76, 1065-1072, doi:10.1016/j.joms.2017.10.002.
7. Mishkind, M.C.; Norr, A.M.; Katz, A.C.; Reger, G.M. Review of virtual reality treatment in psychiatry: Evidence versus current
diffusion and use. Current Psychiatry Reports 2017, 19, 80, doi:10.1007/s11920-017-0836-0.
8. Dhamodharan, T.; Thomas, M.; Ramdoss, S.; JothiKumar, K.; SaravanaSundharam, S.; Muthuramalingam, B.; Hussainalikhan,
N.; Ravichandran, S.; Vadivel, V.; Suresh, P. Cognitive rehabilitation for autism children mental status observation using virtual
reality based interactive environment. In Proceedings of the International Conference on Intelligent Human Systems Integration,
Modena, Italy, 19–21 February, 2020; pp. 1213-1218.
9. Parsons, S.; Cobb, S. State-of-the-art of virtual reality technologies for children on the autism spectrum. European Journal of Special
Needs Education 2011, 26, 355-366, doi:10.1080/08856257.2011.593831.
10. Mosher, M.A.; Carreon, A.C. Teaching social skills to students with autism spectrum disorder through augmented, virtual and
mixed reality. Research in Learning Technology 2021, 29, doi:10.25304/rlt.v29.2626.
11. Dechsling, A.; Shic, F.; Zhang, D.; Marschik, P.B.; Esposito, G.; Orm, S.; Sütterlin, S.; Kalandadze, T.; Øien, R.A.; Nordahl-Hansen,
A. Virtual reality and naturalistic developmental behavioral interventions for children with autism spectrum disorder. Res. Dev.
Disabil. 2021, 111, 103885, doi:10.1016/j.ridd.2021.103885.
12. Wilson, B.A. Cognitive rehabilitation: How it is and how it might be. J. Int. Neuropsychol. Soc. 1997, 3, 487-496,
doi:10.1017/S1355617797004876.
13. Clare, L.; Wilson, B.A.; Carter, G.; Hodges, J.R. Cognitive rehabilitation as a component of early intervention in alzheimer's
disease: A single case study. Aging Ment. Health 2003, 7, 15-21, doi:10.1080/1360786021000045854.
14. Cipriani, G.; Bianchetti, A.; Trabucchi, M. Outcomes of a computer-based cognitive rehabilitation program on alzheimer's
disease patients compared with those on patients affected by mild cognitive impairment. Arch. Gerontol. Geriatr. 2006, 43, 327-
335, doi:10.1016/j.archger.2005.12.003.
15. Seelye, A.M.; Schmitter-Edgecombe, M.; Das, B.; Cook, D.J. Application of cognitive rehabilitation theory to the development
of smart prompting technologies. IEEE Rev. Biomed. Eng. 2012, 5, 29-44, doi:10.1109/RBME.2012.2196691.
16. Chen, C.J. Theoretical bases for using virtual reality in education. Themes in Science and Technology Education 2010, 2, 71-90.
17. Hedberg, J.; Alexander, S. Virtual reality in education: Defining researchable issues. Educational Media International 1994, 31, 214-
220, doi:10.1080/0952398940310402.
18. Kearsley, G.; Shneiderman, B. Engagement theory: A framework for technology-based teaching and learning. Educational
Technology 1998, 38, 20-23.
19. Kolb, D.A. Experiential learning: Experience as the source of learning and development; FT Press: 2014.
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 3 February 2022 doi:10.20944/preprints202202.0056.v1
20. Kalyuga, S. Enhancing instructional efficiency of interactive e-learning environments: A cognitive load perspective. Educ.
Psychol. Rev. 2007, 19, 387-399, doi:10.1007/s10648-007-9051-6.
21. Wang, X.; Laffey, J.; Xing, W.; Galyen, K.; Stichter, J. Fostering verbal and non-verbal social interactions in a 3D collaborative
virtual learning environment: A case study of youth with autism spectrum disorders learning social competence in isocial.
Educational Technology Research and Development 2017, 65, 1015-1039, doi:10.1007/s11423-017-9512-7.
22. McCleery, J.P.; Zitter, A.; Solórzano, R.; Turnacioglu, S.; Miller, J.S.; Ravindran, V.; Parish-Morris, J. Safety and feasibility of an
immersive virtual reality intervention program for teaching police interaction skills to adolescents and adults with autism.
Autism Res. 2020, 13, 1418-1424, doi:10.1002/aur.2352.
23. Schmidt, M.; Glaser, N. Investigating the usability and learner experience of a virtual reality adaptive skills intervention for
adults with autism spectrum disorder. Educational Technology Research and Development 2021, 69, 1665–1699, doi:10.1007/s11423-
021-10005-8.
24. Miller, I.T.; Wiederhold, B.K.; Miller, C.S.; Wiederhold, M.D. Virtual reality air travel training with children on the autism
spectrum: A preliminary report. Cyberpsychology, Behavior, and Social Networking 2020, 23, 10-15, doi:10.1089/cyber.2019.0093.
25. Schneider, S.; Beege, M.; Nebel, S.; Schnaubert, L.; Rey, G.D. The cognitive-affective-social theory of learning in digital
environments (CASTLE). Educ. Psychol. Rev. 2021, 1-38, doi:10.1007/s10648-021-09626-5.
26. Kort, B.; Reilly, R.; Picard, R.W. An affective model of interplay between emotions and learning: Reengineering educational
pedagogy—building a learning companion. In Proceedings of the IEEE International Conference on Advanced Learning
Technologies, Madison, WI, USA, 6-8 Aug., 2001; pp. 43-46.
27. Ip, H.H.-S.; Byrne, J.; Cheng, S.-H.; Kwok, R.C.-W. The samal model for affective learning. In 17th international conference on
distributed multimedia systems, DMS 2011; Knowledge Systems Institute Graduate School: 2011; pp. 216-221.
28. Kwok, R.C.-W.; Cheng, S.H.; Ip, H.H.-S.; Kong, J.S.-L. Design of affectively evocative smart ambient media for learning. In
Proceedings of the 2009 Workshop on Ambient Media Computing, Beijing, China, 2009; pp. 65–76.
29. Bambury, S. The depths of VR model v2.0. Available online: https://www.virtualiteach.com/post/the-depths-of-vr-model-v2-0
(accessed on 13 April 2021).
30. Gigante, M.A. Virtual reality: Definitions, history and applications. In Virtual reality systems, Earnshaw, R.A., Gigante, M.A.,
Jones, H., Eds.; Academic Press: Boston, 1993; pp. 3-14.
31. Stewart Rosenfield, N.; Lamkin, K.; Re, J.; Day, K.; Boyd, L.; Linstead, E. A virtual reality system for practicing conversation
skills for children with autism. Multimodal Technologies and Interaction 2019, 3, doi:10.3390/mti3020028.
32. Mesa-Gresa, P.; Gil-Gómez, H.; Lozano-Quilis, J.A.; Gil-Gómez, J.A. Effectiveness of virtual reality for children and adolescents
with autism spectrum disorder: An evidence-based systematic review. Sensors 2018, 18, 2486, doi:10.3390/s18082486.
33. Eskes, G.A.; Bryson, S.E.; McCormick, T.A. Comprehension of concrete and abstract words in autistic children. J. Autism Dev.
Disord. 1990, 20, 61-73.
34. Cromby, J.; Standen, P.J.; Brown, D.J. The potentials of virtual environments in the education and training of people with
learning disabilities. Journal of Intellectual Disability Research 1996, 40, 489-501.
35. Samson, A.C.; Phillips, J.M.; Parker, K.J.; Shah, S.; Gross, J.J.; Hardan, A.Y. Emotion dysregulation and the core features of
autism spectrum disorder. J. Autism Dev. Disord. 2014, 44, 1766-1772, doi:10.1007/s10803-013-2022-5.
36. Trevarthen, C.; Delafield-Butt, J.T. Autism as a developmental disorder in intentional movement and affective engagement.
Front. Integr. Neurosci. 2013, 7, 49, doi:10.3389/fnint.2013.00049.
37. Bradley, R.; Newbutt, N. Autism and virtual reality head-mounted displays: A state of the art systematic review. Journal of
Enabling Technologies 2018, 12, 101-113, doi:10.1108/JET-01-2018-0004.
38. Browning, D.R.; Cruz-Neira, C.; Sandin, D.J.; DeFanti, T.A. The CAVE automatic virtual environment: Projection-based virtual
environments and disability. In Proceedings of the The First Annual International Conference, Virtual Reality and People with
Disabilities, San Francisco, CA, USA, 1st June, 1993.
39. Li, C.; Ip, H.H.S.; Ma, P.K. A design framework of virtual reality enabled experiential learning for children with autism spectrum
disorder. In Proceedings of the International Conference on Blended Learning, Hradec Kralove, Czech Republic, 2-4 July, 2019;
pp. 93-102.
40. Cruz-Neira, C.; Sandin, D.J.; DeFanti, T.A. Surround-screen projection-based virtual reality: The design and implementation of
the CAVE. In Proceedings of the 20th Annual Conference on Computer Graphics and Interactive Techniques, Anaheim, CA,
USA, 2-6 August, 1993; pp. 135-142.
41. Ip, H.H.S.; Li, C. Virtual reality-based learning environments: Recent developments and ongoing challenges. In Proceedings of
the Hybrid Learning: Innovation in Educational Practices, Cham, 2015; pp. 3-14.
42. Alizadeh, M. Virtual reality in the language classroom: Theory and practice. CALL-EJ (Computer Assisted Language Learning
Electronic Journal) 2019, 20, 21-30.
43. Gigante, M.A. Virtual reality: Enabling technologies. In Virtual reality systems, Earnshaw, R.A., Gigante, M.A., Jones, H., Eds.;
Academic Press: Boston, 1993; pp. 15-25.
44. Kandalaft, M.R.; Didehbani, N.; Krawczyk, D.C.; Allen, T.T.; Chapman, S.B. Virtual reality social cognition training for young
adults with high-functioning autism. J. Autism Dev. Disord. 2013, 43, 34-44, doi:10.1007/s10803-012-1544-6.
45. Doniger, G.M.; Beeri, M.S.; Bahar-Fuchs, A.; Gottlieb, A.; Tkachov, A.; Kenan, H.; Livny, A.; Bahat, Y.; Sharon, H.; Ben-Gal, O.;
et al. Virtual reality-based cognitive-motor training for middle-aged adults at high alzheimer's disease risk: A randomized
controlled trial. Alzheimer's & Dementia: Translational Research & Clinical Interventions 2018, 4, 118-129,
doi:https://doi.org/10.1016/j.trci.2018.02.005.
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 3 February 2022 doi:10.20944/preprints202202.0056.v1
46. Bouchard, S.; Dumoulin, S.; Robillard, G.; Guitard, T.; Klinger, É.; Forget, H.; Loranger, C.; Roucaut, F.X. Virtual reality
compared with in vivo exposure in the treatment of social anxiety disorder: A three-arm randomised controlled trial. Br. J.
Psychiatry 2017, 210, 276-283, doi:10.1192/bjp.bp.116.184234.
47. Rus-Calafell, M.; Gutiérrez-Maldonado, J.; Ribas-Sabaté, J. A virtual reality-integrated program for improving social skills in
patients with schizophrenia: A pilot study. J. Behav. Ther. Exp. Psychiatry 2014, 45, 81-89, doi:10.1016/j.jbtep.2013.09.002.
48. Strickland, D.; Marcus, L.M.; Mesibov, G.B.; Hogan, K. Brief report: Two case studies using virtual reality as a learning tool for
autistic children. J. Autism Dev. Disord. 1996, 26, 651-659, doi:10.1007/BF02172354.
49. Li, C.; Yuan, S.; Ip, H. A case study on delivering virtual reality learning for children with autism spectrum disorder using
virtual reality headsets. In Proceedings of the 10th International Conference on Education and New Learning Technologies
(EDULEARN18), Palma de Mallorca, Spain, 2-4 July, 2018; pp. 728-734.
50. Newbutt, N.; Bradley, R.; Conley, I. Using virtual reality head-mounted displays in schools with autistic children: Views,
experiences, and future directions. Cyberpsychology, Behavior, and Social Networking 2019, 23, 23-33, doi:10.1089/cyber.2019.0206.
51. Newbutt, N.; Sung, C.; Kuo, H.-J.; Leahy, M.J.; Lin, C.-C.; Tong, B. Brief report: A pilot study of the use of a virtual reality
headset in autism populations. J. Autism Dev. Disord. 2016, 46, 3166-3176, doi:10.1007/s10803-016-2830-5.
52. Sigman, M.; Dijamco, A.; Gratier, M.; Rozga, A. Early detection of core deficits in autism. Mental Retardation and Developmental
Disabilities Research Reviews 2004, 10, 221-233, doi:10.1002/mrdd.20046.
53. Hale, C.M.; Tager-Flusberg, H. Social communication in children with autism: The relationship between theory of mind and
discourse development. Autism 2005, 9, 157-178, doi:10.1177/1362361305051395.
54. Uljarevic, M.; Hamilton, A. Recognition of emotions in autism: A formal meta-analysis. J. Autism Dev. Disord. 2013, 43, 1517-
1526, doi:10.1007/s10803-012-1695-5.
55. Zhang, M.; Xu, S.; Chen, Y.; Lin, Y.; Ding, H.; Zhang, Y. Recognition of affective prosody in autism spectrum conditions: A
systematic review and meta-analysis. Autism 2021, doi:10.1177/1362361321995725.
56. Lahiri, U.; Warren, Z.; Sarkar, N. Design of a gaze-sensitive virtual social interactive system for children with autism. IEEE
Transactions on Neural Systems and Rehabilitation Engineering 2011, 19, 443-452, doi:10.1109/TNSRE.2011.2153874.
57. Sigman, M.; Mundy, P.; Sherman, T.; Ungerer, J. Social interactions of autistic, mentally retarded and normal children and their
caregivers. Journal of Child Psychology and Psychiatry 1986, 27, 647-656, doi:10.1111/j.1469-7610.1986.tb00189.x.
58. Nadig, A.; Shaw, H. Acoustic and perceptual measurement of expressive prosody in high-functioning autism: Increased pitch
range and what it means to listeners. J. Autism Dev. Disord. 2012, 42, 499-511, doi:10.1007/s10803-011-1264-3.
59. Paul, R.; Bianchi, N.; Augustyn, A.; Klin, A.; Volkmar, F.R. Production of syllable stress in speakers with autism spectrum
disorders. Res. Autism Spectr. Disord. 2008, 2, 110-124, doi:10.1016/j.rasd.2007.04.001.
60. Tager-Flusberg, H.; Anderson, M. The development of contingent discourse ability in autistic children. Journal of Child Psychology
and Psychiatry 1991, 32, 1123-1134, doi:10.1111/j.1469-7610.1991.tb00353.x.
61. Tager-Flusberg, H. Dissociations in form and function in the acquisition of language by autistic children. In Constraints on
language acquisition: Studies of atypical children, Tager-Flusberg, H., Ed.; Erlbaum: Hillsdale, NJ, 1994.
62. Hale, C.M.; Tager-Flusberg, H. Brief report: The relationship between discourse deficits and autism symptomatology. J. Autism
Dev. Disord. 2005, 35, 519-524, doi:10.1007/s10803-005-5065-4.
63. Heerey, E.A.; Keltner, D.; Capps, L.M. Making sense of self-conscious emotion: Linking theory of mind and emotion in children
with autism. Emotion 2003, 3, 394-400, doi:10.1037/1528-3542.3.4.394.
64. Baron-Cohen, S.; Tager-Flusberg, H.; Cohen, D.J., (Eds.) Understanding other minds: Perspectives from autism. Oxford University
Press: New York, NY, 1994.
65. Baron-Cohen, S.; Tager-Flusberg, H.; Cohen, D.J., (Eds.) Understanding other minds: Perspectives from developmental cognitive
neuroscience, 2nd ed. 2 ed.; Oxford University Press: New York, NY, 2000.
66. Tager-Flusberg, H.; Paul, R.; Lord, C. Language and communication in autism. In Handbook of autism and pervasive developmental
disorders: Diagnosis, development, neurobiology, and behavior, vol. 1, 3rd ed.; John Wiley & Sons Inc: Hoboken, NJ, US, 2005; pp. 335-
364.
67. Baio, J.; Wiggins, L.; Christensen, D.L.; Maenner, M.J.; Daniels, J.; Warren, Z.; Kurzius-Spencer, M.; Zahorodny, W.; Robinson
Rosenberg, C.; White, T.; et al. Prevalence of autism spectrum disorder among children aged 8 years - autism and developmental
disabilities monitoring network, 11 sites, United States, 2014. Morbidity and Mortality Weekly Report. Surveillance Summaries
(Washington, D.C.: 2002) 2018, 67, 1-23, doi:10.15585/mmwr.ss6706a1.
68. Sun, X.; Allison, C.; Wei, L.; Matthews, F.E.; Auyeung, B.; Wu, Y.Y.; Griffiths, S.; Zhang, J.; Baron-Cohen, S.; Brayne, C. Autism
prevalence in china is comparable to western prevalence. Mol. Autism 2019, 10, 7, doi:10.1186/s13229-018-0246-0.
69. Kim, Y.S.; Leventhal, B.L.; Koh, Y.-J.; Fombonne, E.; Laska, E.; Lim, E.-C.; Cheon, K.-A.; Kim, S.-J.; Kim, Y.-K.; Lee, H.; et al.
Prevalence of autism spectrum disorders in a total population sample. Am. J. Psychiatry 2011, 168, 904-912,
doi:10.1176/appi.ajp.2011.10101532.
70. Lai, D.-C.; Tseng, Y.-C.; Hou, Y.-M.; Guo, H.-R. Gender and geographic differences in the prevalence of autism spectrum
disorders in children: Analysis of data from the national disability registry of taiwan. Res. Dev. Disabil. 2012, 33, 909-915,
doi:10.1016/j.ridd.2011.12.015.
71. Matson, J.L.; Kozlowski, A.M. The increasing prevalence of autism spectrum disorders. Res. Autism Spectr. Disord. 2011, 5, 418-
425, doi:10.1016/j.rasd.2010.06.004.
72. Nevison, C.; Blaxill, M.; Zahorodny, W. California autism prevalence trends from 1931 to 2014 and comparison to national ASD
data from idea and addm. J. Autism Dev. Disord. 2018, 48, 4103-4117, doi:10.1007/s10803-018-3670-2.
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 3 February 2022 doi:10.20944/preprints202202.0056.v1
73. Lavelle, T.A.; Weinstein, M.C.; Newhouse, J.P.; Munir, K.; Kuhlthau, K.A.; Prosser, L.A. Economic burden of childhood autism
spectrum disorders. Pediatrics 2014, 133, e520, doi:10.1542/peds.2013-0763.
74. Ghaziuddin, M. Asperger syndrome: Associated psychiatric and medical conditions. Focus Autism Other Dev. Disabl. 2002, 17,
138-144, doi:10.1177/10883576020170030301.
75. White, S.W.; Oswald, D.; Ollendick, T.; Scahill, L. Anxiety in children and adolescents with autism spectrum disorders. Clin.
Psychol. Rev. 2009, 29, 216-229, doi:10.1016/j.cpr.2009.01.003.
76. Myles, B.S.; Barnhill, G.P.; Hagiwara, T.; Griswold, D.E.; Simpson, R.L. A synthesis of studies on the intellectual, academic,
social/emotional and sensory characteristics of children and youth with Asperger syndrome. Education and Training in Mental
Retardation and Developmental Disabilities 2001, 36, 304-311.
77. Fernández-Herrero, J.; Lorenzo, G.; Lledó, A. A bibliometric study on the use of virtual reality (VR) as an educational tool for
high-functioning autism spectrum disorder (ASD) children. In Contemporary perspective on child psychology and education,
Çetinkaya, Ş., Ed.; IntechOpen: 2018; pp. 59-81.
78. Jang, J.; Matson, J.L.; Williams, L.W.; Tureck, K.; Goldin, R.L.; Cervantes, P.E. Rates of comorbid symptoms in children with
ASD, ADHD, and comorbid ASD and ADHD. Res. Dev. Disabil. 2013, 34, 2369-2378, doi:10.1016/j.ridd.2013.04.021.
79. Vuilleumier, P. Facial expression and selective attention. Current Opinion in Psychiatry 2002, 15, 291-300, doi:10.1097/00001504-
200205000-00011.
80. Chita-Tegmark, M. Social attention in ASD: A review and meta-analysis of eye-tracking studies. Res. Dev. Disabil. 2016, 48, 79-
93, doi:10.1016/j.ridd.2015.10.011.
81. Parsons, S.; Mitchell, P. The potential of virtual reality in social skills training for people with autistic spectrum disorders. Journal
of Intellectual Disability Research 2002, 46, 430-443, doi:10.1046/j.1365-2788.2002.00425.x.
82. Serret, S.; Hun, S.; Iakimova, G.; Lozada, J.; Anastassova, M.; Santos, A.; Vesperini, S.; Askenazy, F. Facing the challenge of
teaching emotions to individuals with low- and high-functioning autism using a new serious game: A pilot study. Mol. Autism
2014, 5, 37, doi:10.1186/2040-2392-5-37.
83. Losh, M.; Capps, L. Narrative ability in high-functioning children with autism or asperger's syndrome. J. Autism Dev. Disord.
2003, 33, 239-251, doi:10.1023/A:1024446215446.
84. Shahab, M.; Taheri, A.; Mokhtari, M.; Shariati, A.; Heidari, R.; Meghdari, A.; Alemi, M. Utilizing social virtual reality robot (v2r)
for music education to children with high-functioning autism. Education and Information Technologies 2021, doi:10.1007/s10639-
020-10392-0.
85. Gotham, K.; Brunwasser, S.M.; Lord, C. Depressive and anxiety symptom trajectories from school age through young adulthood
in samples with autism spectrum disorder and developmental delay. J. Am. Acad. Child Adolesc. Psychiatry 2015, 54, 369-376.e363,
doi:10.1016/j.jaac.2015.02.005.
86. Simpson, R.L.; de Boer-Ott, S.R.; Smith-Myles, B. Inclusion of learners with autism spectrum disorders in general education
settings. Topics in Language Disorders 2003, 23, 116-133.
87. Williams, K.R. The son-rise program® intervention for autism: Prerequisites for evaluation. Autism 2006, 10, 86-102,
doi:10.1177/1362361306062012.
88. Chaytor, N.; Schmitter-Edgecombe, M. The ecological validity of neuropsychological tests: A review of the literature on
everyday cognitive skills. Neuropsychol. Rev. 2003, 13, 181-197, doi:10.1023/B:NERV.0000009483.91468.fb.
89. Burgess, P.W.; Alderman, N.; Forbes, C.; Costello, A.; M-acoates, L.; Dawson, D.R.; Anderson, N.D.; Gilbert, S.J.; Dumontheil,
I.; Channon, S. The case for the development and use of "ecologically valid" measures of executive function in experimental and
clinical neuropsychology. J. Int. Neuropsychol. Soc. 2006, 12, 194-209, doi:10.1017/S1355617706060310.
90. Parsons, T.D. Virtual reality for enhanced ecological validity and experimental control in the clinical, affective and social
neurosciences. Front. Hum. Neurosci. 2015, 9, doi:10.3389/fnhum.2015.00660.
91. Neisser, U. Memory: What are the important questions. In Memory observed: Remembering in natural contexts, Neisser, U., Ed.;
Freeman: San Francisco, 1982; pp. 3–19.
92. Banaji, M.R.; Crowder, R.G. The bankruptcy of everyday memory. American Psychologist 1989, 44, 1185-1193, doi:10.1037/0003-
066X.44.9.1185.
93. Didehbani, N.; Allen, T.; Kandalaft, M.; Krawczyk, D.; Chapman, S. Virtual reality social cognition training for children with
high functioning autism. Comput. Human Behav. 2016, 62, 703-711, doi:10.1016/j.chb.2016.04.033.
94. Newbutt, N.; Sung, C.; Kuo, H.; Leahy, M.J. The potential of virtual reality technologies to support people with an autism
condition: A case study of acceptance, presence and negative effects. Annual Review of Cybertherapy and Telemedicine 2016, 14,
149-154.
95. Cromby, J.; Standen, P.; Newman, J.; Tasker, H. Successful transfer to the real world of skills practised in a virtual environment
by students with severe learning difficulties. In Proceedings of the Proceedings of the 1st International Conference on Disability,
Virtual Reality and Associated Technologies (IDCVRAT), Reading, UK, 1996.
96. Wallace, S.; Parsons, S.; Westbury, A.; White, K.; White, K.; Bailey, A. Sense of presence and atypical social judgments in
immersive virtual environments: Responses of adolescents with autism spectrum disorders. Autism 2010, 14, 199-213,
doi:10.1177/1362361310363283.
97. Lahiri, U. Scope of virtual reality to autism intervention. In A computational view of autism; Springer: Cham, 2020; pp. 83-130.
98. Servotte, J.-C.; Goosse, M.; Campbell, S.H.; Dardenne, N.; Pilote, B.; Simoneau, I.L.; Guillaume, M.; Bragard, I.; Ghuysen, A.
Virtual reality experience: Immersion, sense of presence, and cybersickness. Clinical Simulation in Nursing 2020, 38, 35-43,
doi:10.1016/j.ecns.2019.09.006.
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 3 February 2022 doi:10.20944/preprints202202.0056.v1
99. Santhanam, S.p.; Hewitt, L.E. Perspectives of adults with autism on social communication intervention. Communication Disorders
Quarterly 2021, 42, 156-165, doi:10.1177/1525740120905501.
100. Pallathra, A.A.; Calkins, M.E.; Parish-Morris, J.; Maddox, B.B.; Perez, L.S.; Miller, J.; Gur, R.C.; Mandell, D.S.; Schultz, R.T.;
Brodkin, E.S. Defining behavioral components of social functioning in adults with autism spectrum disorder as targets for
treatment. Autism Res. 2018, 11, 488-502, doi:10.1002/aur.1910.
101. Nijman, S.A.; Veling, W.; Greaves-Lord, K.; Vermeer, R.R.; Vos, M.; Zandee, C.E.R.; Zandstra, D.C.; Geraets, C.N.W.; Pijnenborg,
G.H.M. Dynamic interactive social cognition training in virtual reality (discovr) for social cognition and social functioning in
people with a psychotic disorder: Study protocol for a multicenter randomized controlled trial. BMC Psychiatry 2019, 19, 272,
doi:10.1186/s12888-019-2250-0.
102. Cheng, Y.; Ye, J. Exploring the social competence of students with autism spectrum conditions in a collaborative virtual learning
environment – the pilot study. Computers & Education 2010, 54, 1068-1077, doi:10.1016/j.compedu.2009.10.011.
103. Kuriakose, S.; Lahiri, U. Understanding the psycho-physiological implications of interaction with a virtual reality-based system
in adolescents with autism: A feasibility study. IEEE Transactions on Neural Systems and Rehabilitation Engineering 2015, 23, 665-
675, doi:10.1109/TNSRE.2015.2393891.
104. Lahiri, U.; Bekele, E.; Dohrmann, E.; Warren, Z.; Sarkar, N. A physiologically informed virtual reality based social
communication system for individuals with autism. J. Autism Dev. Disord. 2015, 45, 919-931, doi:10.1007/s10803-014-2240-5.
105. Cheng, Y.; Huang, C.-L.; Yang, C.-S. Using a 3D immersive virtual environment system to enhance social understanding and
social skills for children with autism spectrum disorders. Focus Autism Other Dev. Disabl. 2015, 30, 222-236,
doi:10.1177/1088357615583473.
106. Taryadi; Kurniawan, I. The improvement of autism spectrum disorders on children communication ability with pecs method
multimedia augmented reality-based. Journal of Physics: Conference Series 2018, 947, 012009, doi:10.1088/1742-6596/947/1/012009.
107. Zapata-Fonseca, L.; Froese, T.; Schilbach, L.; Vogeley, K.; Timmermans, B. Sensitivity to social contingency in adults with high-
functioning autism during computer-mediated embodied interaction. Behavioral Sciences 2018, 8, doi:10.3390/bs8020022.
108. Lorenzo, G.; Pomares, J.; Lledó, A. Inclusion of immersive virtual learning environments and visual control systems to support
the learning of students with Asperger syndrome. Computers & Education 2013, 62, 88-101, doi:10.1016/j.compedu.2012.10.028.
109. Bernardini, S.; Porayska-Pomsta, K.; Sampath, H. Designing an intelligent virtual agent for social communication in autism. In
Proceedings of the AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment, Boston, Massachusetts,
USA, 14-18 October 2013.
110. Porayska-Pomsta, K.; Anderson, K.; Bernardini, S.; Guldberg, K.; Smith, T.; Kossivaki, L.; Hodgins, S.; Lowe, I. Building an
intelligent, authorable serious game for autistic children and their carers. In Proceedings of the Advances in Computer
Entertainment, Cham, 2013; pp. 456-475.
111. Burke, S.L.; Bresnahan, T.; Li, T.; Epnere, K.; Rizzo, A.; Partin, M.; Ahlness, R.M.; Trimmer, M. Using virtual interactive training
agents (vita) with adults with autism and other developmental disabilities. J. Autism Dev. Disord. 2018, 48, 905-912,
doi:10.1007/s10803-017-3374-z.
112. Smith, M.J.; Ginger, E.J.; Wright, M.; Wright, K.; Boteler Humm, L.; Olsen, D.; Bell, M.D.; Fleming, M.F. Virtual reality job
interview training for individuals with psychiatric disabilities. Journal of Nervous and Mental Disease 2014, 202, 659-667,
doi:10.1097/NMD.0000000000000187.
113. Smith, M.J.; Ginger, E.J.; Wright, K.; Wright, M.A.; Taylor, J.L.; Boteler Humm, L.; Olsen, D.E.; Bell, M.D.; Fleming, M.F. Virtual
reality job interview training in adults with autism spectrum disorder. J. Autism Dev. Disord. 2014, 44, 2450-2463,
doi:10.1007/s10803-014-2113-y.
114. Smith, M.J.; Fleming, M.F.; Wright, M.A.; Losh, M.; Boteler Humm, L.; Olsen, D.; Bell, M.D. Brief report: Vocational outcomes
for young adults with autism spectrum disorders at six months after virtual reality job interview training. J. Autism Dev. Disord.
2015, 45, 3364-3369, doi:10.1007/s10803-015-2470-1.
115. Strickland, D.C.; Coles, C.D.; Southern, L.B. Jobtips: A transition to employment program for individuals with autism spectrum
disorders. J. Autism Dev. Disord. 2013, 43, 2472-2483, doi:10.1007/s10803-013-1800-4.
116. Yang, Y.J.D.; Allen, T.; Abdullahi, S.M.; Pelphrey, K.A.; Volkmar, F.R.; Chapman, S.B. Neural mechanisms of behavioral change
in young adults with high-functioning autism receiving virtual reality social cognition training: A pilot study. Autism Res. 2018,
11, 713-725, doi:10.1002/aur.1941.
117. Russo-Ponsaran, N.; McKown, C.; Johnson, J.; Russo, J.; Crossman, J.; Reife, I. Virtual environment for social information
processing: Assessment of children with and without autism spectrum disorders. Autism Res. 2018, 11, 305-317,
doi:10.1002/aur.1889.
118. Stichter, J.P.; Laffey, J.; Galyen, K.; Herzog, M. Isocial: Delivering the social competence intervention for adolescents (SCI-A) in
a 3D virtual learning environment for youth with high functioning autism. J. Autism Dev. Disord. 2014, 44, 417-430,
doi:10.1007/s10803-013-1881-0.
119. Zhang, L.; Warren, Z.; Swanson, A.; Weitlauf, A.; Sarkar, N. Understanding performance and verbal-communication of children
with ASD in a collaborative virtual environment. J. Autism Dev. Disord. 2018, 48, 2779-2789, doi:10.1007/s10803-018-3544-7.
120. Zhang, L.; Weitlauf, A.S.; Amat, A.Z.; Swanson, A.; Warren, Z.E.; Sarkar, N. Assessing social communication and collaboration
in autism spectrum disorder using intelligent collaborative virtual environments. J. Autism Dev. Disord. 2020, 50, 199-211,
doi:10.1007/s10803-019-04246-z.
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 3 February 2022 doi:10.20944/preprints202202.0056.v1
121. Zhao, H.; Swanson, A.R.; Weitlauf, A.S.; Warren, Z.E.; Sarkar, N. Hand-in-hand: A communication-enhancement collaborative
virtual reality system for promoting social interaction in children with autism spectrum disorders. IEEE Transactions on Human-
Machine Systems 2018, 48, 136-148, doi:10.1109/THMS.2018.2791562.
122. Castelli, F. Understanding emotions from standardized facial expressions in autism and normal development. Autism 2005, 9,
428-449, doi:10.1177/1362361305056082.
123. Baron-Cohen, S.; Golan, O.; Ashwin, E. Can emotion recognition be taught to children with autism spectrum conditions?
Philosophical Transactions of the Royal Society B: Biological Sciences 2009, 364, 3567-3574, doi:10.1098/rstb.2009.0191.
124. Lorenzo, G.; Lledó, A.; Pomares, J.; Roig, R. Design and application of an immersive virtual reality system to enhance emotional
skills for children with autism spectrum disorders. Computers & Education 2016, 98, 192-205, doi:10.1016/j.compedu.2016.03.018.
125. Yang, Y.J.D.; Allen, T.; Abdullahi, S.M.; Pelphrey, K.A.; Volkmar, F.R.; Chapman, S.B. Brain responses to biological motion
predict treatment outcome in young adults with autism receiving virtual reality social cognition training: Preliminary findings.
Behaviour Research and Therapy 2017, 93, 55-66, doi:10.1016/j.brat.2017.03.014.
126. Ke, F.; Im, T. Virtual-reality-based social interaction training for children with high-functioning autism. The Journal of Educational
Research 2013, 106, 441-461, doi:10.1080/00220671.2013.832999.
127. Ip, H.H.S.; Wong, S.W.L.; Chan, D.F.Y.; Byrne, J.; Li, C.; Yuan, V.S.N.; Lau, K.S.Y.; Wong, J.Y.W. Virtual reality enabled training
for social adaptation in inclusive education settings for school-aged children with autism spectrum disorder (ASD). In
Proceedings of the Blended Learning: Aligning Theory with Practices, Cham, 2016; pp. 94-102.
128. Schwarze, A.; Freude, H.; Niehaves, B. Advantages and propositions of learning emotion recognition in virtual reality for people
with autism. Stockholm & Uppsala, Sweden, June 8-14, 2019.
129. Modugumudi, Y.R.; Santhosh, J.; Anand, S. Efficacy of collaborative virtual environment intervention programs in emotion
expression of children with autism. Journal of Medical Imaging and Health Informatics 2013, 3, 321-325, doi:10.1166/jmihi.2013.1167.
130. Bekele, E.; Wade, J.; Bian, D.; Fan, J.; Swanson, A.; Warren, Z.; Sarkar, N. Multimodal adaptive social interaction in virtual
environment (MASI-VR) for children with autism spectrum disorders (ASD). In Proceedings of the 2016 IEEE Virtual Reality
(VR), Greenville, South Carolina, USA, 19-23 March, 2016; pp. 121-130.
131. Kim, K.; Rosenthal, M.Z.; Gwaltney, M.; Jarrold, W.; Hatt, N.; McIntyre, N.; Swain, L.; Solomon, M.; Mundy, P. A virtual joy-
stick study of emotional responses and social motivation in children with autism spectrum disorder. J. Autism Dev. Disord. 2015,
45, 3891-3899, doi:10.1007/s10803-014-2036-7.
132. Kim, K.; Geiger, P.; Herr, N.; Rosenthal, M. The virtual reality emotion sensitivity test (v-rest): Development and construct
validity. In Proceedings of the Association for Behavioral and Cognitive Therapies (ABCT) Conference, San Francisco, CA,
November 18–21, 2010.
133. Kohls, G.; Chevallier, C.; Troiani, V.; Schultz, R.T. Social 'wanting' dysfunction in autism: Neurobiological underpinnings and
treatment implications. J. Neurodev. Disord. 2012, 4, 10, doi:10.1186/1866-1955-4-10.
134. Chevallier, C.; Kohls, G.; Troiani, V.; Brodkin, E.S.; Schultz, R.T. The social motivation theory of autism. Trends Cogn. Sci. 2012,
16, 231-239, doi:10.1016/j.tics.2012.02.007.
135. Cleland, J.; Gibbon, F.E.; Peppé, S.J.E.; O'Hare, A.; Rutherford, M. Phonetic and phonological errors in children with high
functioning autism and Asperger syndrome. Int. J. Speech Lang. Pathol. 2010, 12, 69-76, doi:10.3109/17549500903469980.
136. Bosseler, A.; Massaro, D.W. Development and evaluation of a computer-animated tutor for vocabulary and language learning
in children with autism. J. Autism Dev. Disord. 2003, 33, 653-672, doi:10.1023/B:JADD.0000006002.82367.4f.
137. Saadatzi, M.N.; Pennington, R.C.; Welch, K.C.; Graham, J.H. Small-group technology-assisted instruction: Virtual teacher and
robot peer for individuals with autism spectrum disorder. J. Autism Dev. Disord. 2018, 48, 3816-3830, doi:10.1007/s10803-018-
3654-2.
138. Taylor, B.A.; DeQuinzio, J.A. Observational learning and children with autism. Behav. Modif. 2012, 36, 341-360,
doi:10.1177/0145445512443981.
139. Nubia, R.M.; Fabián, G.R.; Wilson, R.A.; Wilmer, P.B. Development of a mobile application in augmented reality to improve the
communication field of autistic children at a neurorehabilitar clinic. In Proceedings of the 2015 Workshop on Engineering
Applications - International Congress on Engineering (WEA), Bogota, Colombia, 28-30 Oct., 2015; pp. 1-6.
140. Chen, F.; Wang, L.; Peng, G.; Yan, N.; Pan, X. Development and evaluation of a 3-D virtual pronunciation tutor for children
with autism spectrum disorders. PLoS One 2019, 14, e0210858, doi:10.1371/journal.pone.0210858.
141. Iacoboni, M.; Dapretto, M. The mirror neuron system and the consequences of its dysfunction. Nature Reviews Neuroscience 2006,
7, 942-951, doi:10.1038/nrn2024.
142. Loomis, J.M.; Blascovich, J.J.; Beall, A.C. Immersive virtual environment technology as a basic research tool in psychology.
Behavior Research Methods, lnstruments, & Computers 1999, 31, 557-564, doi:10.3758/bf03200735.
143. de la Rosa, S.; Breidt, M. Virtual reality: A new track in psychological research. British Journal of Psychology 2018, 109, 427-430,
doi:10.1111/bjop.12302.
144. Parsons, S. Authenticity in virtual reality for assessment and intervention in autism: A conceptual review. Educational Research
Review 2016, 19, 138-157, doi:10.1016/j.edurev.2016.08.001.
145. Parsons, S.; Mitchell, P.; Leonard, A. Do adolescents with autistic spectrum disorders adhere to social conventions in virtual
environments? Autism 2005, 9, 95-117, doi:10.1177/1362361305049032.
146. Kinateder, M.; Ronchi, E.; Nilsson, D.; Kobes, M.; Müller, M.; Pauli, P.; Mühlberger, A. Virtual reality for fire evacuation research.
In Proceedings of the 2014 Federated Conference on Computer Science and Information Systems, Warsaw, Poland, September
7-10, 2014; pp. 313-321.
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 3 February 2022 doi:10.20944/preprints202202.0056.v1
147. Ip, H.H.S.; Wong, S.W.L.; Chan, D.F.Y.; Byrne, J.; Li, C.; Yuan, V.S.N.; Lau, K.S.Y.; Wong, J.Y.W. Enhance emotional and social
adaptation skills for children with autism spectrum disorder: A virtual reality enabled approach. Computers & Education 2018,
117, 1-15, doi:10.1016/j.compedu.2017.09.010.
148. Michela, A.; van Rooij, M.M.J.W.; Klumpers, F.; van Peer, J.M.; Roelofs, K.; Granic, I. Reducing the noise of reality. Psychol. Inq.
2019, 30, 203-210, doi:10.1080/1047840X.2019.1693872.
149. Lanier, M.; Waddell, T.F.; Elson, M.; Tamul, D.J.; Ivory, J.D.; Przybylski, A. Virtual reality check: Statistical power, reported
results, and the validity of research on the psychology of virtual reality and immersive environments. Comput. Human Behav.
2019, 100, 70-78, doi:10.1016/j.chb.2019.06.015.
150. Nowak, K.L.; Biocca, F. The effect of the agency and anthropomorphism on users' sense of telepresence, copresence, and social
presence in virtual environments. Presence: Teleoperators and Virtual Environments 2003, 12, 481-494,
doi:10.1162/105474603322761289.
151. Georgescu, A.L.; Kuzmanovic, B.; Roth, D.; Bente, G.; Vogeley, K. The use of virtual characters to assess and train non-verbal
communication in high-functioning autism. Front. Hum. Neurosci. 2014, 8, doi:10.3389/fnhum.2014.00807.
152. Nowak, K.L. The influence of anthropomorphism and agency on social judgment in virtual environments. Journal of Computer-
Mediated Communication 2004, 9, JCMC925, doi:10.1111/j.1083-6101.2004.tb00284.x.
153. Bryant, L.; Brunner, M.; Hemsley, B. A review of virtual reality technologies in the field of communication disability:
Implications for practice and research. Disability and Rehabilitation: Assistive Technology 2020, 15, 365-372,
doi:10.1080/17483107.2018.1549276.
154. Stanney, K.M.; Kennedy, R.S.; Drexler, J.M. Cybersickness is not simulator sickness. Proceedings of the Human Factors and
Ergonomics Society Annual Meeting 1997, 41, 1138-1142, doi:10.1177/107118139704100292.
155. Spiegel, J.S. The ethics of virtual reality technology: Social hazards and public policy recommendations. Sci. Eng. Ethics 2018, 24,
1537-1550, doi:10.1007/s11948-017-9979-y.
156. Madary, M.; Metzinger, T. Recommendations for good scientific practice and the consumers of VR-technology. Frontiers in
Robotics and AI 2016, 3, doi:10.3389/frobt.2016.00003.
157. Golding, J.F. Motion sickness susceptibility questionnaire revised and its relationship to other forms of sickness. Brain Res. Bull.
1998, 47, 507-516, doi:10.1016/S0361-9230(98)00091-4.
158. Dechsling, A.; Orm, S.; Kalandadze, T.; Sütterlin, S.; Øien, R.A.; Shic, F.; Nordahl-Hansen, A. Virtual and augmented reality in
social skills interventions for individuals with autism spectrum disorder: A scoping review. J. Autism Dev. Disord. 2021,
doi:10.1007/s10803-021-05338-5.
159. Frankel, F.; Whitham, C. Parent-assisted group treatment for friendship problems of children with autism spectrum disorders.
Brain Res. 2011, 1380, 240-245, doi:10.1016/j.brainres.2010.09.047.
160. Schreibman, L.; Anderson, A. Focus on integration: The future of the behavioral treatment of autism. Behav. Ther. 2001, 32, 619-
632, doi:10.1016/S0005-7894(01)80012-5.
161. Lovaas, O.I. Behavioral treatment and normal educational and intellectual functioning in young autistic children. J. Consult.
Clin. Psychol. 1987, 55, 3-9, doi:10.1037/0022-006X.55.1.3.
162. Tomasello, M.; Farrar, M.J. Joint attention and early language. Child Development 1986, 57, 1454-1463, doi:10.2307/1130423.
163. Landa, R. Early communication development and intervention for children with autism. Mental Retardation and Developmental
Disabilities Research Reviews 2007, 13, 16-25, doi:10.1002/mrdd.20134.
164. Thelen, E. Grounded in the world: Developmental origins of the embodied mind. Infancy 2000, 1, 3-28,
doi:10.1207/S15327078IN0101_02.
165. Peppé, S.; McCann, J.; Gibbon, F.; O’Hare, A.; Rutherford, M. Receptive and expressive prosodic ability in children with high-
functioning autism. J. Speech. Lang. Hear. Res. 2007, 50, 1015-1028, doi:10.1044/1092-4388(2007/071).
166. Aguilar, L. Learning prosody in a video game-based learning approach. Multimodal Technologies and Interaction 2019, 3, 51,
doi:10.3390/mti3030051.
167. Rhea, P.; Augustyn, A.; Klin, A.; Volkmar, F.R. Perception and production of prosody by speakers with autism spectrum
disorders. J. Autism Dev. Disord. 2005, 35, 205-220, doi:10.1007/s10803-004-1999-1.
168. Iovannone, R.; Dunlap, G.; Huber, H.; Kincaid, D. Effective educational practices for students with autism spectrum disorders.
Focus Autism Other Dev. Disabl. 2003, 18, 150-165, doi:10.1177/10883576030180030301.
169. Wang, X.; Wang, S.; Fan, Y.; Huang, D.; Zhang, Y. Speech-specific categorical perception deficit in autism: An event-related
potential study of lexical tone processing in Mandarin-speaking children. Sci. Rep. 2017, 7, 43254, doi:10.1038/srep43254.
170. Lu, Y.-F. Tone processing and the acquisition of tone in Mandarin-and English-speaking typically developing children and
children with autism spectrum disorder. Doctoral thesis, University College London, 2016.
171. Sharmin, M.; Hossain, M.M.; Saha, A.; Das, M.; Maxwell, M.; Ahmed, S. From research to practice: Informing the design of
autism support smart technology. In Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems,
Montreal QC, Canada, 2018; p. Paper 102.
172. Stahmer, A.C.; Schreibman, L.; Cunningham, A.B. Toward a technology of treatment individualization for young children with
autism spectrum disorders. Brain Res. 2011, 1380, 229-239, doi:10.1016/j.brainres.2010.09.043.
173. Nuske, H.J.; Vivanti, G.; Dissanayake, C. Are emotion impairments unique to, universal, or specific in autism spectrum disorder?
A comprehensive review. Cognition and Emotion 2013, 27, 1042-1061, doi:10.1080/02699931.2012.762900.
174. Gernsbacher, M.A.; Morson, E.M.; Grace, E.J. Language development in autism. In Neurobiology of language, Hickok, G., Small,
S.L., Eds.; Academic Press: San Diego, 2016; pp. 879-886.
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 3 February 2022 doi:10.20944/preprints202202.0056.v1
175. Harris, S.L.; Handleman, J.S.; Gordon, R.; Kristoff, B.; Fuentes, F. Changes in cognitive and language functioning of preschool
children with autism. J. Autism Dev. Disord. 1991, 21, 281-290, doi:10.1007/BF02207325.
176. Mirzaei, M.R.; Ghorshi, S.; Mortazavi, M. Audio-visual speech recognition techniques in augmented reality environments. The
Visual Computer 2014, 30, 245-257, doi:10.1007/s00371-013-0841-1.
177. Harvey, A.; McCrindle, R.J.; Lundqvist, K.; Parslow, P. Automatic speech recognition for assistive technology devices. In
Proceedings of the ICDVRAT 2010: The Eighth International Conference on Disability Virtual Reality and Associated
Technologies, Valparaiso, Chile, 31 Aug-2 Sept, 2010; pp. 273-282.
178. Moon, J.; Ke, F.; Sokolikj, Z. Automatic assessment of cognitive and emotional states in virtual reality-based flexibility training
for four adolescents with autism. Br. J. Educat. Tech. 2020, 51, 1766-1784, doi:10.1111/bjet.13005.
179. Lombardo, M.V.; Lai, M.-C.; Baron-Cohen, S. Big data approaches to decomposing heterogeneity across the autism spectrum.
Mol. Psychiatry 2019, 24, 1435-1450, doi:10.1038/s41380-018-0321-0.
180. Schroeder, J.H.; Desrocher, M.; Bebko, J.M.; Cappadocia, M.C. The neurobiology of autism: Theoretical applications. Res. Autism
Spectr. Disord. 2010, 4, 555-564, doi:10.1016/j.rasd.2010.01.004.
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 3 February 2022 doi:10.20944/preprints202202.0056.v1
