The Effect of Multimodal Virtual Reality Experience on the Emotional
Responses Related to Injections
Katherine Chin, Marissa Thompson and Mounia Ziat
Information Design and Corporate Communication, Bentley University, 175 Forest Street, Waltham, U.S.A.
Trypanophobia, Mid-air Haptics, Virtual Reality, Emotional Regulation, Distraction Therapy, Fear Reduction,
Pain Reduction.
The objective of this study is to determine if using a multimodal experience, haptics and audio in a virtual
environment, can change the emotional responses related to injections. Participants were poked with a blunt
end needle in three conditions, where they were asked to look away from the needle, look at the needle
directly, or interact haptically with bubbles in a virtual environment. Participants were asked to rate the arousal
(calm-fear), valence (happy-unhappy), and pressure felt (no pressure-high pressure) for each trial. Our results
showed that participants preferred the haptics-VR condition as indicated by their comments and significant
valence scores. They described the simulation as relaxing, fun, and pleasant. The results support the idea that
multisensory simulation can be effective in increasing participants’ happiness through distraction in stressful
or fearful situations.
In the current work, we investigated whether distrac-
tion using a multimodal experience of mid-air haptics
in a virtual environment can reduce the anxiety and
stress related to needles as opposed to an experience
without multimodal stimulation. Furthermore, condi-
tions of looking directly at the injection site or look-
ing away from it were tested. We relied on a tactile
phenomenon known as tactile suppression (Ziat et al.,
2010) where a tactile stimulation is suppressed by an-
other tactile stimulus. Because our central nervous
system receives a vast amount of sensorimotor infor-
mation, the brain has developed a mechanism to sup-
press some incoming information. Putting this into
application, using tactile feedback can help suppress
the tactile sensation coming from the needle. While
we did not directly address a sensory suppression in
this study; which can be visual, auditory, or haptic,
the phenomenon has been studied in multiple sensory
modalities (Porcu et al., 2014).
Several studies have already explored the influ-
ence of haptics on emotions in a multimodal context
(Eid and Al Osman, 2015) (Tsalamlal et al., 2018)
(Ziat and Raisamo, 2017) and the effectiveness of
haptics for pain treatment. One study reported signif-
icant results of tactile feedback reducing deafferenta-
tion pain through a multimodal experience using a
VR headset and vibrotactile motors on the hand (Sano
et al., 2016). Another notable study tested ultrasound
tactile stimulation with virtual reality for pain distrac-
tion. Authors found a pain tolerance increase and
higher-than-midpoint values for valence and arousal,
indicating more positive emotions associated with the
multimodal experience (Karafotias et al., 2017).
Virtual reality has been proven to effectively reduce
perceived pain. For burn patients undergoing painful
treatments while using virtual reality, a reduction of
activity in the pain-related areas in the brain has been
observed in the insula, the thalamus, and the pri-
mary and secondary somatosensory cortex (Hoffman,
2004) (Das et al., 2005). Another study showed that
haptic feedback can enhance the realism of a virtual
reality experience (Krogmeier et al., 2019).
The healthcare industry is always looking for
means to help individuals overcome fear and pain.
Injections, magnetic resonance imaging scans, pre-
operative and post-operative care, blood draws, blood
donations, and waiting rooms are situations where
people experience high anxiety or pain. (Canbulat
et al., 2014) (Ditto and France, 2006) (Hamilton,
1995) (Kain et al., 2006) (Karanci and Dirik, 2003)
(Munn and Jordan, 2013) (Pineault, 2007).
Chin, K., Thompson, M. and Ziat, M.
The Effect of Multimodal Virtual Reality Experience on the Emotional Responses Related to Injections.
DOI: 10.5220/0010195601280134
In Proceedings of the 16th Inter national Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications (VISIGRAPP 2021) - Volume 2: HUCAPP, pages
ISBN: 978-989-758-488-6
2021 by SCITEPRESS Science and Technology Publications, Lda. All rights reserved
When it comes to injections, up to two thirds
of children and one fourth of parents are afraid of
needles (Taddio et al., 2012). It is more common
for children than adults to suffer from needle-related
or injection phobia/fear, known as Belonephobia or
Trypanophobia (Doctor et al., 2008) (Orenius et al.,
2018), and the need for distraction in younger chil-
dren may be greater than in older children. In a study
on how children perceive pain, children reported nee-
dle related procedures as very painful (Kortesluoma
and Nikkonen, 2004). Treating children who have a
fear of needles can also be a stressful and difficult ex-
perience for nurses (Ives and Melrose, 2010).
When administering immunizations, a study has
shown that distraction can be a more effective means
to help children cope with pain and fear than parental
comfort (Manimala et al., 2000). In another study
where children were distracted by an iPad during im-
munizations, parents reported that the children expe-
rienced less distress, crying, and need for being held
(Shahid et al., 2015).
As children are a demographic that displays high anx-
iety during injections (Taddio et al., 2012), we, first,
conducted interviews with three parents to get a better
understanding of the immunization process for chil-
dren. We wanted to learn about the feelings expe-
rienced by patients during injections and the strate-
gies used by parents and practitioners to help children
cope with the fear and pain.
Parents were asked to walk through their chil-
dren’s experiences while getting an injection and dis-
cuss the most difficult aspects of this experience.
They rated their perception of children’s valence on
a scale from 1 to 5 (extremely unhappy-extremely
happy). They were also asked what comforting strate-
gies they try on their children before and during injec-
tions, how receptive the children were to toys when
stressed, and what were the most effective methods
for calming the children. Parents were asked how im-
portant they felt it was that hospitals would ease the
tension during injections on a scale of 1 to 5 not im-
portant -very important) and what they believe would
be an ideal injection process.
Parents reported that their children were less
happy before and during injections, and the children
were usually scared when seeing a doctor or nurse.
Easing the tension during an injection was very im-
portant for parents as they can become stressed from
the non-cooperation of their children. They usually
bring toys, and often pat their children to calm them
down. Overall, this short survey shows that injec-
tions are negative experiences for children and par-
ents, with parents believing that positive injection ex-
periences are important, and touch brings comfort to
their children. These preliminary interviews were
used for collecting additional qualitative findings to
inform the direction of the study; this data had less
bearing on the results.
In the current work, we wanted to test the effect of
multimodal experiences beyond visual and auditory
sensations on fear and pain. Our hypothesis was par-
ticipants would rate arousal, valence, and pressure
lower when they were poked with the needle during
the tactile-VR simulation. The null hypothesis is that
there would be no difference in ratings between par-
ticipants’ experience when using the virtual simula-
tion and when not using the virtual simulation. Our
objective is to discover if multimodal experiences re-
duce fear and pain as well as increase happiness dur-
ing injections. During and after ratings were collected
for a VR experience that lasts over time. For this
study, each trial was short in requesting before and
during the rating experience.
4.1 Participants
5 adult participants between the ages of 24 and 64
were recruited, including 2 males and 3 females. Due
to the COVID-19 lockdown which mandated limited
contact with others, participants were volunteers from
the entourage of the authors themselves. It was not
possible to recruit participants in-person at this time.
Nevertheless, the requirement for a minimum number
of participants for a formative study was met (Nielsen,
2000). They were provided with a consent form to
agree to their voluntary participation to the experi-
ment. Some participants may have an emotional re-
action to seeing a nurse or doctor. For this reason, we
chose to minimize the injector’s visual presence and
dialogue to isolate the condition most suitable for this
experiment, the needle itself.
Figure 1: A syringe with a blunt needle tip was used for the
mock injections.
The Effect of Multimodal Virtual Reality Experience on the Emotional Responses Related to Injections
Figure 2: The mock injection was administered two inches
below the wrist.
4.2 Apparatus
A syringe with a blunt needle tip was used (Fig. 1)
for ethical and safety consideration during the exper-
iment. The syringe resembles an injection needle,
which provides a more realistic experience of an ac-
tual injection. In Fig. 2, the needle tip was applied
to the same area, two inches below from the wrist,
on the ventral side participants’ left forearms for each
trial. Although there may be multiple injection sites,
we chose to use the site most common for IVs. It is
important to note that the injection site was consistent
for all the participants.
For tactile feedback, an Ultraleap STRATOS Ex-
plore development kit was used. It consists of an ul-
trasound mid-air haptics array and a hand tracking
sensor. The 192-transducer array emits ultrasound
into the user’s hand to create tactile sensations. Ad-
ditionally, the sensor’s camera tracks the spatial ori-
entation of the user’s hand in real time. The virtual
hand, which is displayed over a virtual array that rep-
resents the Ultraleap device, can interact with virtual
bubbles and feel tactile sensations concurrently. The
Oculus Rift CV1. was used during the virtual inter-
action to view and hear the virtual environment. Al-
though VR headsets are recommended for those 13
and older, the concerns involving younger children
are mainly for long-term usage. Younger children can
still use a VR headset, but for a limited time, which is
relatively short when a nurse is providing a shot.
4.3 Stimuli
In this test, three visual conditions were compared:
“Look Away” where participants are looking away
from the injection arm, “Look At” where participants
are asked to look directly at the injection arm, and
“Simulation, where participants are exploring a vir-
Figure 3: Multimodal VR experience of nature environment
visuals, popping bubbles tactile feedback, and waterfall au-
tual environment and feeling tactile feedback when
they interact with objects. Both Look Away and Look
At conditions were included to mimic common injec-
tion scenarios yet separate biasness of seeing the in-
jection or anticipating the shot.
For the Simulation condition, a nature virtual re-
ality environment was built using Unity (Unity, n.d.)
as shown in Fig. 3. A nature setting was used to
induce the biophilia effect (Kellert, 1995) (Lidwell
et al., 2010) (Wells, 2000), also known as healing
through nature, which helps participants feel more re-
laxed and less stressed when presented with a real or
artificial visual depiction of nature. In this environ-
ment, the viewer stood on a boulder surrounded by a
pool of water and cliffs. They could also view a pink
willow tree to their left and a waterfall to their right.
Waterfall ambient noise, which resembles the sound
of a high waterfall with a substantial volume of water
crashing into a pool of water, was added to enhance
the realism of the setting.
For the tactile feedback, participants placed their
hand on the virtual array (Gray block under the virtual
hand in Fig. 4) and began popping bubbles. The ul-
trasound array created tactile waves on the skin when
bubbles popped or collided with the virtual hand. An
auditory feedback of the popping bubble was heard
each time a bubble was popped by the participant to
reinforce the tactile sensation.
The environment setup was similar to an injection
chair that is commonly used in a doctor’s office. Par-
ticipants sat in a chair with each of their forearms rest-
ing on elevated platforms (small tables and boxes) as
shown in Fig. 4a. The ergonomics of this layout also
ensures that neither arm will experience fatigue. The
ultrasound array was placed approximately 20 cen-
timeters below the participants’ right hand for opti-
mal accuracy in hand detection, as demonstrated in
Fig. 4b.
Additionally to the three visual conditions (Look
HUCAPP 2021 - 5th International Conference on Human Computer Interaction Theory and Applications
Figure 4: (a) Ergonomics were considered to prevent arm
fatigue by utilizing a table and boxes as armrests. (b) Ultra-
sound array is placed approximately 20 centimeters under
the right hand.
at, Look Away, Simulation), there was a contact con-
dition where a pressure was applied on the skin with
the cannula, and a no-contact condition where the
needle hovered over the area without touching the
skin. These two injection types prevent participants
from becoming accustomed with the needle stimulus
and to avoid any anticipation about the contact with
the needle. A total of 18 trials (3 visual x 2 injection
x 3 repetitions) were run for each participant with a
randomized order.
For each trial, participants were asked to report
whether they felt a sensation of pressure on their
skin. If participants’ answer was affirmative, addi-
tional questions related to valence, arousal, and pres-
sure were asked. More specifically, on a 10 point
scale, participants were asked to provide a score for
the arousal dimension, with one representing calm
and a score of ten representing fear. For valence, a
score of one represented happy and a score of ten rep-
resented unhappy. Finally, for pressure, a score of one
represented feeling no pressure and a score of ten rep-
resented feeling high pressure.
After the experiment, there was a verbal follow-up
with the participants where they reported any phobia
of needles and ranked the three conditions and modal-
ities (visual, auditory, tactile) by preference.
Fig. 5 displays the grand mean ratings of valence,
arousal, and pressure for the three conditions (Look
Away, Look At, Simulation). Because of a small sam-
ple and the nature of the data (ordinal), the difference
in arousal, valence, and pressure ratings were anal-
ysed using the non-parametric Friedman test. Our
hypothesis is participants will have lower ratings for
arousal, valence, and pressure in the simulation con-
dition than the other two conditions.
For valence, Friedman test was significant (χ
5.65, p <0.05). In the simulation condition, the ma-
jority of participants felt calmer as the mean valence
rating was the lowest for participants. The test was
not significant for both arousal (χ
= 3.44, p >0.05)
and pressure (χ
= 2.21, p >0.05).
Although the data for arousal and pressure did not
show a statistically significant difference, the ratings
for the Simulation condition were lower than the Look
At or Look Away conditions. The means for the Look
Away and Look At conditions were closer to each
other (see Fig. 5).
Figure 5: Grand mean for the ”Look Away, ”Look At, and
”Pressure” conditions among the participants. From left to
right: Arousal, Valence, and Pressure ratings.
6.1 Post-survey
Participants were asked to rank the conditions from
highest preference to lowest preference. They all
chose the Simulation condition first, the Look At con-
dition second, and the Look Away condition third.
One of the participants reported Trypanophobia but
her responses were not different from the other par-
They described the Simulation condition as “re-
laxing, “calming, “peaceful, and “immersive.
They also mentioned that the simulation disengaged
attention away from injections. The popping bubbles
were often labelled as “pleasant, “fun, and “realis-
tic, while the haptic feedback made the simulation
more effective in distracting them from the needle.
One participant explained that if the bubbles were not
included in the environment, it would have been less
effective. Additionally, participants mentioned that
both visual and auditory effects of the waterfall were
realistic and relaxing. Finally, seeing the virtual hand
interact with the haptic bubbles enhanced the realism
The Effect of Multimodal Virtual Reality Experience on the Emotional Responses Related to Injections
of the simulation.
Participants least favoured the Look Away condi-
tion. They all preferred to see the needle than wait
for the action to happen. Participants disliked the an-
ticipation factor of the Look Away condition because
they were waiting anxiously for the needle to make
contact with their skin as opposed to knowing when
the needle would poke the skin. They stated that the
visual feedback made them feel “calmer, “at ease,
and “in control” since they felt there was a sense of
comfort to see what the needle would do to the skin.
Moreover, for the Look Away and Look At condi-
tions, participants had found the room environment
“more boring” and “less interesting” than the virtual
environment. For the ranking of the modalities, the
visual and tactile conditions were ranked first by two
participants each, while one participant ranked the
auditory condition first. The second most favourite
modalities were tactile and auditory by two partici-
pants each.
Our study shows that multimodal immersive expe-
riences can increase happiness, reduce anxiety and
boredom, and potentially reduce fear for adults re-
ceiving injections. Although the participants were
only adults, it can be inferred that the responses would
be stronger in children since findings from a previ-
ous study showed a greater percentage of children
than adults experienced trypanophobia (Taddio et al.,
2012). Multimodal experiences are also highly pre-
ferred as a distraction tool for unpleasant experiences.
Participants favoured and expressed positive senti-
ments about the simulation. They described the sim-
ulation as relaxing, fun, and enjoyable. The data re-
vealed that arousal and pressure ratings were not sig-
nificant, but the data for the valence rating was signif-
icant. This indicates that participants felt significantly
happier during the virtual simulation than when they
looked away or looked at the injection site.
In addition, all participants correctly identified if
stimuli had made contact or no contact to their arms.
The fact that participants reported that the multi-
modal condition was an effective distraction from the
syringe suggests that sensory suppression occurred.
Similar studies have examined the effect of virtual re-
ality and haptic sensation for pain distraction. One
study showed that when there is physical interaction
in a virtual reality experience, tactile feedback can in-
crease pain tolerance (Karafotias et al., 2017). Our
study differs by focusing on the multimodal expe-
rience without isolating the VR, haptic, or auditory
conditions separately. The study was designed to
more closely simulate conditions that may occur in a
healthcare facility by isolating the look at, look away,
or multimodal experience conditions.
In the future, we would like to further investigate
the timing and location of the injection, the devices
and visualizations used, the age and number of partic-
ipants, and how closely the experiment would match
an actual doctors office. Since suppression phenom-
ena are very complex and ill understood, investigating
the timing and location of the mock injection’s tactile
stimulation (same arm vs different arm) emitted from
the haptic array would allow a better understanding of
how different locations and timing influence suppres-
As we had tested virtual reality and tactile concur-
rently, it would be beneficial to test the tactile, visual,
and auditory sensations separately to compare uni-
modal versus multimodal effectiveness. This could
help determine which sensations are the most effec-
tive in unimodal and multimodal situations. Addition-
ally, non-contract mid-air haptics and contact tactile
feedback, such as surface touch (Meyer et al., 2014)
or vibrotactile haptics (Ziat et al., 2006) (Ziat et al.,
2005), could be compared to investigate how the na-
ture of the haptic stimulation affects the level of im-
mersion. Furthermore, many participants preferred to
look at the injection site, so a possible visualization
could be a nurse’s hand holding a syringe as a future
Because of the COVID-19 lockdown, number of
participants were limited to ve. When deemed safe
and possible, we plan to expand the number of partic-
ipants and conduct a summative study on a younger
demographic, potentially adolescent patients between
the ages of 13 and 18. Additionally, a study could be
done with children under 13. Because virtual reality
devices recommend users to be 13 years or older, the
study could be modified for children under 13 years of
age by using a monitor display with speakers instead.
Patients could experience anxiety in real-life sit-
uations induced by an unsettling and unfamiliar hos-
pital environment as well as the administration of the
injection by a staff member. This was not tested in our
current experiment as participants came from the im-
mediate environment of the authors. For this reason,
we would like to extend our experiment to include a
more realistic scenario allowing us to analyze the ef-
fectiveness in real life application.
Finally, the implementation of a similar system
is cost-effective (around $150 USD) using NVIDIA
Jetson Nano Developer Kit, a Google Cardboard VR
headset, a 5-inch cell phone, and a 48-transducer ul-
HUCAPP 2021 - 5th International Conference on Human Computer Interaction Theory and Applications
trasonic directive speaker kit. This would allow prac-
tical application in hospitals without significantly in-
creasing cost.
The authors would like to thank Jia Fogelberg and
Sangjun Yoon for assisting in the data collection of
the pre-experiment survey.
Canbulat, N., Inal, S., and S
onmezer, H. (2014). Efficacy
of distraction methods on procedural pain and anxi-
ety by applying distraction cards and kaleidoscope in
children. Asian Nursing Research, 8(1):23–28.
Das, D. A., Grimmer, K. A., Sparnon, A. L., McRae, S. E.,
and Thomas, B. H. (2005). The efficacy of playing
a virtual reality game in modulating pain for children
with acute burn injuries: a randomized controlled trial
[isrctn87413556]. BMC pediatrics, 5(1):1.
Ditto, B. and France, C. R. (2006). Vasovagal symptoms
mediate the relationship between predonation anxiety
and subsequent blood donation in female volunteers.
Transfusion, 46(6):1006–1010.
Doctor, R. M., Kahn, A. P., and Adamec, C. A. (2008).
The encyclopedia of phobias, fears, and anxieties. In-
fobase Publishing.
Eid, M. A. and Al Osman, H. (2015). Affective haptics:
Current research and future directions. IEEE Access,
Hamilton, J. G. (1995). Needle phobia: a neglected diagno-
sis. Journal of Family Practice, 41(2):169–182.
Hoffman, H. G. (2004). Virtual-reality therapy. Scientific
American, 291(2):58–65.
Ives, M. and Melrose, S. (2010). Immunizing children who
fear and resist needles: is it a problem for nurses? In
Nursing forum, volume 45, pages 29–39. Wiley On-
line Library.
Kain, Z. N., Mayes, L. C., Caldwell-Andrews, A. A.,
Karas, D. E., and McClain, B. C. (2006). Preopera-
tive anxiety, postoperative pain, and behavioral recov-
ery in young children undergoing surgery. Pediatrics,
Karafotias, G., Korres, G., Teranishi, A., Park, W., and Eid,
M. (2017). Mid-air tactile stimulation for pain distrac-
tion. IEEE transactions on haptics, 11(2):185–191.
Karanci, A. and Dirik, G. (2003). Predictors of pre-and
postoperative anxiety in emergency surgery patients.
Journal of psychosomatic research, 55(4):363–369.
Kellert, S. R. (1995). The biophilia hypothesis. Island Press.
Kortesluoma, R.-L. and Nikkonen, M. (2004). ‘i had this
horrible pain’: the sources and causes of pain experi-
ences in 4-to 11-year-old hospitalized children. Jour-
nal of Child Health Care, 8(3):210–231.
Krogmeier, C., Mousas, C., and Whittinghill, D. (2019).
Human–virtual character interaction: Toward under-
standing the influence of haptic feedback. Computer
Animation and Virtual Worlds, 30.
Lidwell, W., Holden, K., and Butler, J. (2010). Universal
principles of design, revised and updated: 125 ways to
enhance usability, influence perception, increase ap-
peal, make better design decisions, and teach through
design. Rockport Pub.
Manimala, M. R., Blount, R. L., and Cohen, L. L. (2000).
The effects of parental reassurance versus distraction
on child distress and coping during immunizations.
Children’s Health Care, 29(3):161–177.
Meyer, D. J., Wiertlewski, M., Peshkin, M. A., and Col-
gate, J. E. (2014). Dynamics of ultrasonic and elec-
trostatic friction modulation for rendering texture on
haptic surfaces. In 2014 IEEE Haptics Symposium
(HAPTICS), pages 63–67. IEEE.
Munn, Z. and Jordan, Z. (2013). Interventions to reduce
anxiety, distress and the need for sedation in adult
patients undergoing magnetic resonance imaging: a
systematic review. International Journal of Evidence-
Based Healthcare, 11(4):265–274.
Nielsen, J. (2000). Why you only need to test with 5 users.
Orenius, T., LicPsych, S
a, H., Mikola, K., and Risto-
lainen, L. (2018). Fear of injections and needle phobia
among children and adolescents: an overview of psy-
chological, behavioral, and contextual factors. SAGE
Open Nursing, 4:2377960818759442.
Pineault, P. (2007). Breast cancer screening: women’s ex-
periences of waiting for further testing. In Oncology
nursing forum, volume 34, page 847. Oncology Nurs-
ing Society.
Porcu, E., Keitel, C., and M
uller, M. M. (2014). Visual,
auditory and tactile stimuli compete for early sensory
processing capacities within but not between senses.
NeuroImage, 97:224–235.
Sano, Y., Wake, N., Ichinose, A., Osumi, M., Oya, R., Sum-
itani, M., Kumagaya, S.-i., and Kuniyoshi, Y. (2016).
Tactile feedback for relief of deafferentation pain us-
ing virtual reality system: a pilot study. Journal of
neuroengineering and rehabilitation, 13(1):61.
Shahid, R., Benedict, C., Mishra, S., Mulye, M., and
Guo, R. (2015). Using ipads for distraction to re-
duce pain during immunizations. Clinical pediatrics,
Taddio, A., Ipp, M., Thivakaran, S., Jamal, A., Parikh,
C., Smart, S., Sovran, J., Stephens, D., and Katz, J.
(2012). Survey of the prevalence of immunization
non-compliance due to needle fears in children and
adults. Vaccine, 30(32):4807–4812.
Tsalamlal, M. Y., Rizer, W., Martin, J.-C., Ammi, M., and
Ziat, M. (2018). Affective communication through
The Effect of Multimodal Virtual Reality Experience on the Emotional Responses Related to Injections
air jet stimulation: Evidence from event-related po-
tentials. International Journal of Human–Computer
Interaction, 34(12):1157–1168.
Wells, N. M. (2000). At home with nature: Effects of
“greenness” on children’s cognitive functioning. En-
vironment and behavior, 32(6):775–795.
Ziat, M., Gapenne, O., Rouze, M.-O., and Delwarde, A.
(2006). Recognition of different scales by using a hap-
tic sensory substitution device. In Proceedings of Eu-
rohaptics, volume 6, pages 3–6.
Ziat, M., Gapenne, O., Stewart, J., and Lenay, C. (2005).
A comparison of two methods of scaling on form
perception via a haptic interface. In Proceedings of
the 7th international conference on Multimodal inter-
faces, pages 236–243.
Ziat, M., Hayward, V., Chapman, C. E., Ernst, M. O., and
Lenay, C. (2010). Tactile suppression of displacement.
Experimental brain research, 206(3):299–310.
Ziat, M. and Raisamo, R. (2017). The cutaneous-rabbit il-
lusion: What if it is not a rabbit? In 2017 IEEE World
Haptics Conference (WHC), pages 540–545. IEEE.
HUCAPP 2021 - 5th International Conference on Human Computer Interaction Theory and Applications