International Journal
Transactionsof JapanofSociety
Affectiveof Engineering
Kansei Engineering
J-STAGE Advance Published Date: 2019.05.10
doi: 10.5057/ijae.IJAE-D-18-00008

ORIGINAL ARTICLE

Affective Vibrotactile Stimuli:
Relation between Vibrotactile Parameters and Affective Responses
Hikaru HASEGAWA, Shogo OKAMOTO, Ken ITO and Yoji YAMADA
Nagoya University, Furo-cho, Chikusa-ku, Nagoya-shi, Aichi 464-8601, Japan

Abstract: Affective communication in the interaction with touch panel displays could be improved by vibrotactile feedback. Hence,
we address the relation between vibrotactile stimuli and affective responses. Specifically, we aim to determine the response tocomprehensive vibrotactile stimulus parameters, i.e., waveform, amplitude, envelope frequency, and rhythm, by rating 48 types ofamplitude-modulated vibrotactile stimuli according to five affective responses: arousal, comfort, preference, familiarity, and dominance.
By determining the effects of each parameter, we found that amplitude and envelope frequency were the most effective parameters
triggering affective responses. Amplitude influenced arousal and dominance positively, and comfort, preference, and familiarity negatively.
Envelope frequency influenced arousal and dominance negatively. In contrast, waveform and rhythm showed lower effectiveness,
which contradicted expected outcomes. Likewise, we verified that affective responses mainly include two dimensions, namely, arousal(and dominance) and comfort (or valence). Overall, the results from this study serve as initial guidelines for designing electronic
devices with affective vibrotactile stimuli.
Keywords: Vibrotactile stimuli, Affective response, Tactile texture display, Amplitude modulation

1. INTRODUCTION
Vibrotactile stimuli can be a source to convey affective
responses through electronic devices such as personal
computers, smartphones, and wearable devices. In fact, thisapplication has been demonstrated in a variety of studies.
For instance, vibrotactile stimuli have been shown to elicit
affective responses including pleasantness, arousal, andurgency [1, 2], and influence the responses to emotionallycharged images such as facial expressions [3, 4]. Hence,affective communication through electronic devices canbe improved by adding vibrotactile feedback to existing
applications such as audiovisual content.
The successful implementation of affective vibrotactile
stimuli depends on establishing the relationship between
the stimuli and human affective responses. In a broader
sense, affective responses to different haptic stimuli havebeen widely studied [5, 6]. However, there is scarceresearch on affective responses elicited by vibrotactile
stimuli, and the related studies did not consider acomprehensive set of parameters [4, 7-10]. For example,
Yoo et al. [7] investigated the affective responses toamplitude-modulated vibrotactile stimuli by controlling
carrier frequency, envelope, and duration, but disregarding
rhythm, which shows affective impacts according tosome studies [8, 9]. In contrast, for this study we investigated comprehensive parameters that can be controlled intypical vibrotactile actuators from commercial electronic
Received: 2018.06.20 / Accepted: 2019.02.25

devices to determine those that elicit the clearest affective
responses. It has practical value to specify vibrotactile
parameters that significantly influence affective responses
under multivariate changes, as this extends previous
studies that only investigated the effects of few types ofparameters on affective responses.
Specifically, in this study, we determine affective
responses considering five types of vibrotactile parameters
and their combination, which enable us to thoroughly
assess the effects of vibrotactile stimuli and determine
the most influential parameters by comparing theireffects. Overall, we use 48 types of vibrotactile stimuli
obtained from variations of the five parameters. Elevenparticipants rate the vibrotactile stimuli according tofive affective responses, which are arousal, comfort,
dominance [4, 5, 7-10], preference, and familiarity. We
then analyze the response rating to determine the mosteffective vibrotactile parameters eliciting human affective
responses. Through the results from this study, we expect
to provide guidelines for the design of devices that include
affective vibrotactile stimuli.
Another important aspect is to determine the structureof affective responses influenced by vibrotactile stimuli.
Understanding the relation between the space of affective
responses and vibrotactile stimuli will be instrumental for
designing effective stimuli. We focus on responses including arousal, comfort, and dominance, derived fromthe Russell’s circumplex model [11]. These responses
are often used to express affective responses depending
Copyright © 2019 Japan Society of Kansei Engineering.
All Rights Reserved.

Advance Publicationa)b)

Figure 1: Vibrotactile stimuli generator for experiments
Diagram of the generator front view (top) andphotograph of the generator (bottom).

on haptic perception in previous studies [4, 5, 7-10].
Moreover, we consider preference and familiarity in thisstudy, as these responses can be beneficial for commercial
applications. We apply the principal component analysis
on these five types of affective responses to acquire theirdimensional structure.
2. VIBROTACTILE STIMULI GENERATOR
We used the same vibrotactile stimuli generator thatwas employed in a previous work [12]. The generator
is composed of X-1741 voice coil actuators (Neomax
Engineering Co. Ltd., Japan) to mechanically stimulate
the fingertips by producing displacements in the normal
direction to the panel, as illustrated in Figure 1. The voicecoil actuators are more responsive than eccentric motors,
which are adopted in some mobile devices and present
single-tone vibration. We activated the voice coil actuators through an ADS 50/5 servo-amplifier (Maxon Motor
AG, Switzerland) and executed a feedforward computerbased control at 1 kHz. To emulate a touch panel, which isone of the most promising applications for vibrotactile
feedback, we mounted a flat panel over four voice coil
actuators as shown in Figure 1.
3. EVALUATED PARAMETERS
Some studies reported parameters of vibrotactile stimuli
that influence human perception including waveform,
frequency, amplitude, and duration [13, 14], as well asrhythm [14-16], from which length and unevenness
showed the highest effectiveness [16].

c)Figure 2: Amplitude-modulated vibrotactile stimulia) Parameters constituting vibrotactile stimuli,
where the duty ratio is given by A/(A+B).
b) Vibrotactile stimulus with reverse sawtooth
waveform and envelope frequency of 250
Hz, which is equal to the carrier frequency.
c) Vibrotactile stimulus with triangular
waveform and duty ratio of 100%.

We employed amplitude-modulated sinusoidal waves
for vibrotactile stimuli, as illustrated in Figure 2, because
it is difficult for voice coil actuators to generate complex
waves, such as a triangular signal, using other approaches.
In addition, these types of waves enabled us to evaluate
low-frequency stimuli evoking large perceptual magnitudes. We fixed the carrier frequency of amplitude
modulation at 250 Hz, because most of the actuators
employed for delivering vibrotactile stimuli are highly
effective when resonating in the range of 100 – 300 Hz [17],which elicits an intense vibrotactile sensation.
Besides waveform, frequency, and amplitude, we
considered rhythm as a parameter of vibrotactile stimuli
in this study, given its reported effectiveness on affective
responses [8, 9]. However, there is no consensus on
the definition of rhythm for vibrotactile stimuli, anddifferent approaches have been proposed. For instance,
either melodies [18, 19] or number of cycles and tone
duration [8] can be used to define rhythm. We selected adefinition similar to the latter for rhythm, where twoparameters are considered, namely, the duration of one
stimulation cycle and its duty ratio given by the rate ofstimulation during one cycle. For example, a duration andduty ratio of 100 ms and 75%, respectively, indicate thatthe one stimulus cycle lasts 75 ms followed by an inactive
period of 25 ms.
Therefore, the five parameters we considered forvibrotactile stimuli are waveform (envelope), envelope
frequency, amplitude, duration, and duty ratio, whose

Advance Publication
Affective Vibrotactile Stimuli: Relation between Vibrotactile Parameters and Affective Responses

Table 1: Parameter specifications of amplitude-modulated
vibrotactile stimuli of which carrier frequency isconstant i.e. 250 Hz.
Parameter

Specification

Waveform

Reverse sawtooth (R),
Triangular (T), Square (S)

30 Hz

L1

L2

L3

L4

R

–

89.4

–

199

T

83.7

99.3

301

–

S

48.6

77.9

–

291

68.3

166

–

330

T

31.4

–

268

443

100, 200, 300, 400

S

–

81.0

–

–

25, 50, 75, 100

R

52.3

68.5

80.5

86.8

T

63.3

89.0

245

297

S

41.8

55.5

198

268

R

50.2

47.6

196

252

T

–

53.6

–

177

S

39.2

52.3

71.1

222

Levels: 1, 2, 3, 4 (L1–L4)

Frequency (Hz)30, 60, 125, 250

Duty ratio (%)

Frequency WaveformR

Amplitude
Duration (ms)Table 2: Stimulus amplitude per frequency

60 Hz

125 Hzspecifications are listed in Table 1. We selected theparameters and their specifications to allow easy
generation, even when using low-fidelity vibrotactile
actuators.
3.1 Waveform
The waveform of vibrotactile stimuli affects perception.
For instance, square waveforms are perceived with more
intensity than triangular and sinusoidal waveforms, which
elicit only moderate responses [20]. Other waveforms
include damped waves and parabolas for modulation [1].
For this study, we tested several types of waveforms,
and some of them resulted in similar vibration profiles
given the dynamics of voice coil actuators. Specifically,
we obtained similar profiles between a damped wave
and a reverse sawtooth, and between a sawtooth and atriangular waveform. Consequently, we restricted ourstudy to three types of waveforms, namely, reverse
sawtooth, triangular, and square. Figure 3 illustrates a
generated triangular wave stimulus, where the stimulus
does not completely agree with its ideal envelope.
3.2 Envelope frequency
Vibrotactile perception becomes monotonically moreacute as frequency approaches 250 Hz [14, 17, 21]. Hence,

Figure 3: Vibrotactile stimulus measured by an accelerometer(black solid line) and target envelope (red dashed line).
Waveform: triangular. Amplitude: Level 3.
Frequency: 30 Hz. Duration: 100 ms.
Duty ratio: 50%.

250 HzL1–L4 represent the amplitude levels, retrieved from an accelerometerin m/s2. The unspecified values represent levels that were not used forthe experiment. L1 stimuli were satisfactorily greater than perceptual
threshold levels.

we evaluated four frequency levels constituting a geometricseries to generate vibrotactile stimuli: 30 Hz, 60 Hz,
125 Hz, and 250 Hz, with the carrier frequency of 250 Hz,
which is illustrated in Figure 2.
3.3 Amplitude
Humans can discriminate up to four levels of vibrotactile
stimulus amplitude [20]. Hence, we considered amplitude
limits from the lower perceptible vibration to the maximum device output, and linearly divided this range into
four levels. The lower limit was determined according to
the perception of the authors, and was then verified
as perceptible by the study participants. Table 2 lists thepeak acceleration values measured by a 2302BW piezoelectric accelerometer (Showa Sokki Corp., Japan) per
amplitude level. These values were also dependent on
waveform.
3.4 Duration and duty ratio
There must be an interval of at least 10 ms to recognize
two subsequent vibrotactile stimuli [20]. From the viewpoint of affective communication through electronic
devices, a short time enhances the transference of affective information from vibrotactile stimuli. In addition,
unpleasant sensations increase with the duration ofvibrotactile stimuli [22]. Considering these aspects, weevaluated four vibrotactile stimulus periods of 100 ms,
200 ms, 300 ms, and 400 ms, as well as four duty ratiosof 25%, 50%, 75%, and 100%. Hence, the minimum
interval between successive stimuli was 25 ms, which isabove the minimum perceptible, and the duty ratio of
100% represented a single continuous stimulus.

Advance Publication

4. METHODS
4.1 Vibrotactile stimuli and affective responses
For the experiments, we designed 48 types of vibrotactile
stimuli from the combination of the abovementioned
parameters. These types were determined using two
L24 cross-tables, which allow to avoid an exhaustive
search in the parameter space and reduce the number ofTable 3: Types of vibrotactile stimuli
No. Waveform Amplitude
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48

R
R
T
S
T
S
S
R
R
S
R
T
S
S
T
T
R
T
T
T
T
T
S
S
R
S
R
T
S
S
R
S
S
R
T
T
S
R
R
R
T
S
T
R
R
R
S
T

L2
L3
L1
L2
L2
L3
L2
L1
L1
L4
L1
L4
L4
L1
L3
L1
L4
L2
L4
L1
L3
L4
L2
L2
L2
L2
L4
L2
L4
L3
L4
L2
L1
L2
L2
L4
L3
L4
L3
L4
L2
L1
L3
L2
L1
L2
L1
L1

Frequency
(Hz)
250
125
30
60
125
250
30
250
60
125
125
60
30
250
30
30
30
250
125
60
125
250
125
125
250
60
60
30
250
125
30
250
250
125
30
60
125
250
250
125
250
125
60
60
60
30
30
125

Duration
(ms)
100
300
300
200
400
400
400
400
300
400
200
100
300
100
100
200
200
200
200
400
100
300
100
300
300
300
200
200
100
400
400
400
200
200
300
400
200
200
300
100
100
400
300
400
100
100
400
100

Duty ratio
(%)
50
25
75
25
25
25
75
100
25
50
75
100
100
75
50
100
25
75
100
50
75
50
25
75
100
50
50
50
100
100
50
50
50
100
25
75
50
75
50
50
25
75
100
100
75
100
25
25

combinations, whereas independency among parameters ismaintained. The stimuli specifications are listed in Table 3,
where unfeasible parameter combinations were excluded,e.g., vibrotactile stimulus with envelope frequency of
30 Hz, duration of 100 ms, and 25% duty ratio, where
the stimulus duration is shorter than a waveform period.
The model that uses arousal, comfort (or valenceaccording to the Russell’s circumplex model), and dominance to describe affective responses is commonly used
to evaluate tactile stimulation [4, 5, 7-10]. Besides thesethree responses, we added familiarity and preference inour experiment, because these terms can convey useful
insights in the design of commercial applications. In fact,terms such as familiarity and approachability are used todetermine stimulus acceptability [23, 24].
4.2 Task
Eleven naive male university students (right handed,
aged between 21 and 24 years old), participated in theexperiment after providing informed consent.
The participants evaluated each vibrotactile stimulus byassigning one out of seven degrees (+3: agree, 0: neutral,–3: disagree) to the five affective responses, after experiencing the stimulus for approximately 5 s. To reproduce asituation where a user is interacting with a touch panel
display, we asked every participant to touch the panel with
his index finger, as shown in Figure 1.
Overall, the participants rated each of the 48 tactile
stimuli, which were randomly presented to prevent theorder effect, and responded the questionnaire on affective
responses. The experiment took approximately 30 min perparticipant. During the experiment, the participant washearing pink noise through noise-cancelling headphones toeliminate the sounds caused by the vibrotactile stimuli
generator.
4.3 Analysis
To discover the most effective parameters for vibrotactile
stimuli, we applied a multiple regression analysis on thesubjective scores. We considered the five parameters ofvibrotactile stimuli (i.e., waveform, envelope frequency,
amplitude, duration, and duty ratio) as explanatory variables,and each affective response as objective variable. The
units of amplitude, envelope frequency, and duration
were meters per square second (m/s2), hertz (Hz), andmilliseconds (ms), respectively. The three types of waveforms were represented by combinations of dummy binary
variables (xr, xt), where r and t denote the reverse sawtooth
wave and triangle wave, respectively. Specifically, thereverse sawtooth, triangle, and square waves can beAdvance Publication
Affective Vibrotactile Stimuli: Relation between Vibrotactile Parameters and Affective Responses

described as (xr, xt) = (1, 0), (0, 1), and (0, 0), respectively.
A positive correlation between the dummy variablecorresponding to a waveform and an affective response
expresses an influence from the former on the latter.
On the other hand, a negative correlation of both dummy
variables with an affective response indicates the effectiveness of the square waveform over that response.
First, we analyzed each participants’ subjective scores,
which were transformed into z-scores, to investigate
individual differences. Then, we collectively analyzed allparticipants’ subjective scores. These analyses enabled to
distinguish the parameters having an individual andgeneral influence.
In addition, to investigate the relation among the affective responses, especially in terms of their dimensionality,
we computed their principal components, whose scores
were determined after applying the promax method.
5. RESULTS
The effective parameters were obtained from theindividuals’ analysis as listed in Table 4. The regression
coefficients obtained by analyzing all the participants’subjective scores are listed in Table 5, and the partial
regression coefficients obtained by individuals’ analysis
are summarized in the appendix. As in Table 5, except
for duration, all the parameters showed some impacts on
affective responses.

The dummy variable corresponding to the triangle
wave negatively influenced comfort, preference, andfamiliarity for a few participants, as shown in Table 4.
In contrast, reverse sawtooth and square wave stimuli
were more comfortable, preferred, and familiar than thetriangle wave stimulus. On the other hand, the triangle
wave influenced arousal negatively in the analysis of allparticipants’ scores, as shown in Table 5. Nonetheless,this effect is inconclusive because it was not confirmedin the individuals’ analysis.
Amplitude positively influenced arousal and dominancein the analyses of all participants (Table 5) and eachindividual (Table 4), whereas it negatively influenced
comfort, preference, and familiarity. This effect was consistent among several participants. These results indicatethat larger amplitude leads to arousing and dominant
responses, as well as discomfort, non-preference, andunfamiliarity.
Envelope frequency negatively influenced arousal anddominance in the analyses of all participants (Table 5)
and each individual (Table 4). Moreover, envelope
frequency positively influenced comfort, preference, andfamiliarity in the individual analysis, although someparticipants exhibited the inverse influence. Arousing
and dominant vibrotactile stimuli were delivered bylowering the envelope frequency, and these stimuli wereperceived less comfortable, preferred, and familiar bysome participants.

Table 4: Summary of positive and negative effects between affective responses and vibrotactile stimuli for each participant
Triangle*waveform
ArousalAmplitude

Envelope
frequency

Duration

Duty ratio

++++
++++

-----

+

--

+++
--++++
-++++
-----

+
--

++
---++
--+
-+
--

Comfort------Preference

-

----

Familiarity

--

-++++
+++

Dominance+-

The signs show the effect trend (i.e., +, positive; -, negative) and their number corresponds to the number of participants for whom significant effects were found. Red signs indicate significant effects (p < .05) and black signs indicate possibly significant effects (p < .10).
*Reverse sawtooth was excluded from this table as it did not show any significant effect.

Table 5: Statistically significant partial regression coefficients obtained from the participants’ scores

ArousalTriangle
waveform-0.46

Amplitude(m/s2)+6.1E-3

Envelope
frequency (Hz)-4.2E-3

Comfort-3.4E-3(+1.3E-3)

Preference-3.2E-3(+1.4E-3)

Familiarity-1.8E-3+1.7E-3

Dominance+3.4E-3-2.9E-3

Values in parentheses indicate possibly significant effects (p < .10).

Duration(ms)

Duty ratio-0.74(-0.38)

Advance Publication

Table 6: Principal component coefficients after applying
the promax method
Response

Comp. 1

Arousal-0.13

Comp. 2
0.63

Comfort

0.58

-0.05

Preference

0.58

-0.01

Familiarity

0.55

0.12

Dominance

0.10

0.76

Duty ratio negatively influenced arousal in the analysisof all participants (Table 5) and might have negatively
influenced on dominance. For some participants, it influenced comfort, preference, and familiarity, but theseeffects were not common, as shown in Table 4. When the
duty ratio of the stimuli was small, such as impulsive
stimuli, they elicited an arousal response.
Two principal components providing a cumulative
contribution ratio of 79% were found from the five types
of affective responses. Table 6 lists the principal component coefficients after rotation using the promax method.
Component 1 was highly related to comfort, preference,and familiarity, whereas component 2 to arousal anddominance. Thus, affective responses during vibrotactile
perception can be categorized in a two-dimensional space.
6. DISCUSSION
In this study, we found that vibration amplitude
and envelope frequency have a significant influence on
affective responses, even under variation of multiple
parameters. This suggests that amplitude and envelope
frequency are the most important parameters to design
affective vibrotactile stimuli. Specifically, amplitude waspositively correlated with arousal and dominance,
confirming results from previous studies, where amplitude was correlated with arousal [4, 7]. Furthermore, likeour work, these studies reported a reduction in comfort
due to large amplitudes, which might be perceived asintense and uncomfortable [22].
Unlike amplitude, the envelope frequency negatively
influenced arousal and dominance, and positively but
moderately influenced comfort, preference, and familiarity.
These effects can be explained by the fact that low
frequency produces a long and continuous vibration. Then,the temporal accumulation of vibrotactile stimuli [25]might have been perceived as more intense and uncomfortable [22]. In addition, the principal component coefficients
indicated that comfort, preference, and familiarity arestrongly correlated, and hence their characterization can beconsidered as semantically similar.

We expressed rhythm by the combination of durationand duty ratio, where the latter influenced arousal negatively, and comfort and preference in an individuallydifferent manner in several participants. When the duty
ratio is small, the stimuli were impulsive, eliciting
arousal and uncomfortable responses [4]. This may
explain the negative and positive effects of the duty
ratio on arousal and comfort (preference), respectively.
Likewise, continuous stimuli (duty ratio: 100%) elicit
comfort and less arousing responses compared to intermittent stimuli [8, 9]. However, when the duty ratio islarge, participants are exposed to longer stimuli. Someparticipants might have evaluated such continued stimuli
as intense and uncomfortable by the temporal accumulation of vibrotactile stimuli [7, 25], which undermined
comfort. Hence, the perceptual effects of the duty ratio
can vary among participants. These individual differencesof the effects of rhythm have been also reported inprevious studies [9]. Nevertheless, Akshita et al. [4]reported the inexistence of affective responses to rhythm
when varying multiple parameters. Our results suggestthat the effects of rhythm on human affective responses
are notably weaker than those of amplitude and frequency. However, rhythm can present clearer effects when it
influences amplitude and carrier frequency [7]. Likewise,rhythm may be useful for discriminating different
vibrotactile stimuli [15].
We did not find general effects of the waveform on
the evaluated affective responses. In an earlier study [4],the effect of waveforms, except for that of impulse trains,
was not prominent. Hence, it appears that unless the
waveforms are clearly distinguishable, such as impulses
compared to continuous waveforms, their elicited affective responses may be insignificant. In addition, thedifference among waveforms can be distinguished only
at low frequencies [26]. Moreover, the ineffectiveness ofwaveform may be due to the difficulty of reproducing itwith high fidelity. In fact, despite using highly responsive
voice coil actuators, we were not able to completely
control the waveform envelope given the actuator andsystem dynamics, as illustrated in Figure 3.
Although the number of participants may not be
sufficient in the present study, most part of our results
stated above are consistent with previous studies.
Especially, the effects of amplitude and envelope
frequency on arousal and comfort, respectively, were also
found in [4, 7, 10]. Nevertheless, further investigation
with a larger number of participants would be helpful toclarify the individuality of the effect of rhythm.
Overall, the analyses suggest that affective responses

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Affective Vibrotactile Stimuli: Relation between Vibrotactile Parameters and Affective Responses

Figure 4: Effect of vibrotactile parameters on two-dimensional
affective responses
Red and blue lines indicate positive and negative
effects, respectively. Dotted lines indicate effects
that depend on the individual.

elicited by vibrotactile stimuli vary over two dimensions,
namely, arousal (dominance) and comfort. Arousal anddominance can be merged, as well as comfort, preference,and familiarity.
The results from this study provided us insights torecommend the following guidelines for designing
vibrotactile stimuli evoking two-dimensional affective
responses, as illustrated in Figure 4. First, the effect on
comfort can be tuned by the amplitude of the stimuli,
which has also some influence on arousal. Next, theeffect on arousal can be tuned by the envelope frequency
or duty ratio. For instance, comfortable and arousing
stimuli can be designed using low envelope frequency
and small amplitude. However, the effects of affective
stimuli designed by this method include individual
differences. Envelope frequency influenced arousal andcomfort inversely for some participants (Table 4). Thus,
the effects of these two parameters are dependent forsome individuals. Concretely, only two types of affective
stimuli, either uncomfortable and arousing or comfortable and less arousing can be elicited by changing thesetwo parameters for such individuals. To design twodimensional affective stimuli, we need at least two
parameters that independently influence the affective
responses. We may need to seek another parameter tocontrol the affective aspects of vibrotactile stimuli withmore independency and clarity.
7. CONCLUSION
We investigated the effects of five parameters ofvibrotactile stimuli, namely, waveform, amplitude,envelope frequency, duration, and duty ratio, on affective
responses. This kind of research is scarce, especiallywith respect to the number of evaluated parameters.

To determine the most effective parameters, we asked
11 participants to evaluate 48 amplitude-modulated
vibrotactile stimuli, which were generated from different
parameter combinations, by providing their affective
responses to each stimulus. The responses included
arousal, comfort, preference, familiarity, and dominance.
We found that amplitude and envelope frequency of thevibrotactile stimuli were the most effective parameters
to influence human affective responses. Especially,
amplitude influenced arousal and dominance positively,
and comfort, preference, and familiarity negatively. On
the other hand, envelope frequency influenced arousaland dominance negatively. We expressed rhythm by the
combination of duration and duty ratio, and it influenced
some participants. Especially, duty ratio influenced arousal
negatively. However, such effect was not consistent among
participants and smaller than the effects of amplitude andenvelope frequency.
The principal component analysis on the subjectivescores revealed a two-dimensional model for affective
responses composed by arousal (and dominance) andcomfort elicited by vibrotactile stimuli. Hence, it may
be sufficient to design affective vibrotactile stimuli byusing two parameters, namely, amplitude and envelope
frequency. However, the effects of these two parameters
were not independent from each other for some participants. Thus, other parameter should be studied to suitably
design affectively attractive vibrotactile stimuli.
This study provided a guideline for designing affective
vibrotactile stimuli for commercial electronic devices
such as touch panel displays and suggests the direction for
future studies on the relationship between vibrotactile
stimuli and affective responses.
ACKNOWLEDGEMENTS
This work was partially supported by MEXT KAKENHI(15H05923 and 17H04697), Japan.

REFERENCES
1. Schneider, O. S., Seifi, H., Kashani, S., Chun, M., andMacLean, K. E.; HapTurk; Crowdsourcing affective
ratings of vibrotactile icons, Proceedings of ACM
CHI Conference on Human Factors in Computing
Systems, pp.3248-3260, 2016.
2. Hasegawa, H., Itoh, K., Okamoto, S., Elfekey, H., andYamada, Y.; Colorful tactile stimuli: Association
between colors and tactile-display stimuli on Russell’s
psychological plane, Haptic Interaction: Science,
Engineering and Design, Lecture Notes in ElectricalAdvance Publication

Engineering, Springer, 432, pp.47-52, 2016.
3. Bonnet, D., Ammi, M., and Martin, J.-C.; Improvement of the recognition of facial expressions withhaptic feedback, Proceedings of IEEE International
Workshop on Haptic Audio Visual Environments andGames, pp.81-87, 2011.
4. Akshita, Sampath, H., Indurkhya, B., Lee, E., andBae, Y.; Towards multimodal affective feedback:Interaction between visual and haptic modalities,
Proceedings of ACM SIGCHI Conference on
Human Factors in Computing Systems, pp.20432052, 2015.
5. Drewing, K., Weyel, C., Celebi, H., and Kaya, D.;Feeling and feelings: Affective and perceptual dimensions of touched materials and their connection,
Proceedings of IEEE World Haptics Conference,
pp.25-30, 2017.
6. Kidoma, K., Okamoto, S., Nagano, H., and Yamada, Y.;
Graphical modeling method of texture-related
affective and perceptual responses, International
Journal of Affective Engineering, 16(1), pp.27-36,
2017.
7. Yoo, Y., Yoo, T., Kong, J., and Choi, S.; Emotional
responses of tactile icons: Effects of amplitude,frequency, duration, and envelope, Proceedings ofIEEE World Haptics Conference, pp.235-240, 2015.
8. Seebode, J., Schleicher, R., Wechsung, I., and Möller, S.;
Investigating the affective impression of tactile feedback on mobile devices, Proceedings of International
BCS Human Computer Interaction Conference, 2013.
9. Seifi, H., and MacLean, K. E.; A first look at individuals’
affective ratings of vibrations, Proceedings of IEEE
World Haptics Conference, pp.605-610, 2013.
10. Suk, H.-J., Jeong, S.-H., Yang, T.-H., and Kwon, D.-S.;
Tactile sensation as emotion elicitor, Kansei Engineering International, 8(2), pp.153-158, 2009.
11. James A. Russell; A circumplex model of affect.
Journal of Personality and Social Psychology, 39(6),pp.1161-1178, 1980.
12. Ito, K., Okamoto, S., Elfekey, H., Kajimoto, H., andYamada, Y.; A texture display using vibrotactile andelectrostatic friction stimuli surpasses one based oneither type of stimulus, Proceedings of IEEE International Conference on Systems, Man, and Cybernetics,
pp.2343-2348, 2017.
13. MacLean, K., and Enriquez, M.; Perceptual design of
haptic icons, Proceedings of EuroHaptics, pp.351-363,
2003.
14. Brewster, S., and Brown, L. M.; Tactons: Structured
tactile messages for non-visual information display,

Proceedings of the 5th Conference on AustralasianUser Interface, 28, pp.15-23, 2004.
15. Brown, L. M., Brewster, S. A., and Purchase, H. C.;
A first investigation into the effectiveness of tactons,
Proceedings of First Joint EuroHaptics Conference
and Symposium on Haptic Interfaces for Virtual
Environment and Teleoperator Systems, pp.167-176,
2005.
16. Ternes, D., and MacLean, K. E.; Designing large setsof haptic icons with rhythm, Haptics: Perception,
Devices and Scenarios, Lecture Notes in Computer
Science, Springer, 5024, pp.199-208, 2008.
17. Jones, L. A. and Sarter, N. B.; Tactile displays:
Guidance for their design and application, Human
Factors, 50(1), pp.90-111, 2008.
18. Swerdfeger, B. A., Fernquist, J., Hazelton, T. W., andMacLean, K. E.; Exploring melodic variance inrhythmic haptic stimulus design, Proceedings ofGraphics Interface, pp.133-140, 2009.
19. van Erp, J. B. F., and Spape, M. M. A.; Distilling theunderlying dimensions of tactile melodies, Proceedingsof EuroHaptics, pp.111-120, 2003.
20. van Erp, J. B. F.; Guideline for the use of vibro-tactile
displays in human computer interaction, Proceedingsof EuroHaptics, pp.18-22, 2002.
21. Gunther, E., and O’Modhrain, S.; Cutaneous grooves:
Composing for the sense of touch, Journal of New
Music Research, 32(4), pp.369-381, 2003.
22. Okamoto, S., Tamada, A., Sumiya, T., and Yokoi, S.;
Design of pleasant vibrotactile stimulation through aseat, Proceedings of IEEE Global Conference on
Consumer Electronics, pp.54-55, 2017.
23. Salminen, K., Surakka, V., Lylykangas, J., Raisamo, J.,
Saarinen, R., Raisamo, R., Rantala, J., and Evreinov, G.;
Emotional and behavioral responses to haptic stimulation, Proceedings of ACM SIGCHI Conference on
Human Factors in Computing Systems, pp.15551562, 2008.
24. Koelstra, S., Muhl, C., Soleymani, M., Lee, J.-S.,
Yazdani, A., Ebrahimi, T., Pun, T., Nijholt, A., andPatras, I.; DEAP: A database for emotion analysis
using physiological signals, IEEE Transactions on
Affective Computing, 3(1), pp.18-31, 2012.
25. Bolanowski, S. J., Gescheider, G. A., Verrillo, R. T.,
and Checkosky, C. M.; Four channels mediate themechanical aspects of touch, Journal of Acoustic
Society of America, 84(5), pp.1680-1694, 1988.
26. Jones, L. A., and Singhal, A.; Perceptual dimensionsof vibrotactile actuators, Proceedings of IEEE Haptic
Symposium, pp.307-312, 2018.

Advance Publication
Affective Vibrotactile Stimuli: Relation between Vibrotactile Parameters and Affective Responses

APPENDIX
Partial regression coefficients from multiple regression analysis of individual participantsParticipant Participant Participant Participant Participant Participant Participant Participant Participant Participant Participant
A
B
C
D
E
F
G
H
I
J
K

ArousalComfortPreference

Familiarity

Dominance

Triangle-0.20(p = .44)

8.3E-2(p = .74)

0.10(p = .66)-0.18(p = .56)-0.32(p = .28)-0.27(p = .36)-0.36(p = .16)-2.3E-3(p = .94)-0.26(p = .40)-0.47(p = .13)-0.41(p = .19)

Amplitude[m/s2]

2.9E-3

4.1E-3

3.6E-3

1.8E-3(p = .16)

2.0E-3(p = .09)

4.1E-3

5.5E-3

3.2E-3

1.6E-3(p = .21)

3.3E-3

1.6E-3(p = .23)

Frequency-5.8E-3[Hz]-4.1E-3-6.5E-3

1.3E-3(p = .45)-4.5E-3-2.2E-3(p = .16)-2.3E-3(p = .11)-3.2E-3

2.2E-3(p = .19)

1.6E-3(p = .33)-2.7E-3(p = .12)

Duration[ms]-3.4E-4(p = .73)-3.0E-4(p = .77)-3.5E-4(p = .68)

1.0E-3(p = .44)-1.6E-3(p = .17)

5.4E-5(p = .96)

4.9E-5(p = .96)-5.1E-4(p = .65)

2.4E-3

1.4E-3(p = .24)

7.4E-4(p = .56)

Duty ratio

0.16(p = .70)

-1.4

0.16
(p = .65)-7.9E-2(p = .88)

0.25(p = .62)-0.54(p = .28)

-1.4

-0.48
(p = .32)

0.31(p = .56)-0.29(p = .58)-0.16(p = .76)

Triangle-6.0E-2(p = .70)-0.35(p = .25)

-0.42

-0.12
(p = .70)

0.24(p = .38)

0.36(p = .24)-4.8E-2(p = .86)-5.1E-2(p = .86)-6.2E-2(p = .84)

0.19(p = .55)-0.54(p = .08)

Amplitude-4.8E-3[m/s2]-1.1E-3(p = .41)-6.4E-4(p = .53)-8.1E-5(p = .95)-1.4E-3(p = .26)-6.5E-4(p = .62)-4.9E-3-4.8E-3-2.5E-3(p = .06)-1.5E-3(p = .26)-2.0E-3(p = .16)

Frequency[Hz]4.5E-3-8.8E-4(p = .61)

7.6E-3-4.9E-4(p = .78)-5.4E-3

1.2E-3(p = .48)-4.5E-3

2.6E-3(p = .09)-3.7E-3-1.0E-3(p =.56)

2.3E-3(p = .19)

Duration[ms]-1.1E-3(p = .21)-2.4E-3(p = .06)-4.5E-5(p = .96)

4.1E-4(p = .75)-2.6E-3-1.5E-3(p = .25)-3.2E-4(p = .77)-1.6E-4(p = 89)-1.6E-3(p = .21)-1.5E-3(p = .23)

2.3E-3(p = .07)

Duty ratio

0.10(p = .81)-0.81(p = .13)

-1.0

0.13
(p = .80)

0.87(p = .06)

0.74(p = .16)-0.80(p = .08)

1.3

-0.82
(p = .10)-0.36(p = .49)-0.96(p = .07)

Triangle

0.27(p = .27)-0.40(p = .19)-0.30-7.9E-17
0.21(p = .19) (p = 1.0) (p = .42)

0.26
(p = .40)-0.30(p = .27)-0.16(p = .59)-3.6E-2(p = .91)-9.0E-2(p = .79)-0.95

Amplitude-4.5E-3[m/s2]-2.0E-3(p = .13)-9.0E-4(p = .40)-1.4E-3(p = .30)-1.1E-3(p = .37)-8.4E-4(p = .52)-4.0E-3-4.4E-3-1.9E-3(p = .15)-1.3E-3(p = .32)-2.1E-3(p = .09)

Frequency[Hz]4.2E-39.0E-4(p = .60)

6.6E-3-9.9E-4(p = .57)

5.0E-3

9.1E-4(p = .60)-3.6E-3

2.8E-3(p = .08)-3.1E-3(p = .07)-1.2E-3(p = .47)

2.5E-3(p = .11)

Duration[ms]-7.9E-4(p = .40)-1.7E-3(p = .19)

4.2E-4(p = .66)-5.9E-4(p = .65)

3.3E-3-8.4E-4(p = .52)-4.0E-4(p = .71)

3.7E-4(p = .74)-1.5E-3(p =.26)-8.1E-4(p = .51)

7.2E-4(p = .54)

Duty ratio-9.7E-2(p = .81)-0.47(p = .37)

-1.4

0.46
(p = .39)

0.91

0.53
(p = .32)

-1.0

1.3

-0.90
(p = .09)-5.6E-2(p = .91)-0.55(p = .25)

Triangle-2.3E-2(p = .93)

0.44(p = .16)-0.26(p = .21)-0.19(p = .53)-0.17(p = .57)

6.1E-2(p = .84)-0.51(p = .07)-5.7E-2(p = .83)-0.34(p = .32)-0.33(p = .28)-0.72

Amplitude -2.3E-3[m/s2](p = .06)

8.0E-4(p = .54)-1.5E-3(p = .11)

1.6E-3(p = .20)-9.0E-4(p = .48)-3.4E-4(p = .78)-3.5E-4(p = .80)-5.3E-3-5.3E-5(p = .68)-1.1E-3(p =.40)-1.1E-3(p = .40)

Frequency[Hz]6.0E-3-2.4E-3(p = .17)

8.4E-3

4.5E-3

4.4E-3

7.9E-4(p = .63)-3.2E-3-1.1E-3(p = .45)-2.2E-3(p = .18)-1.7E-3(p = .32)

2.3E-3(p = .16)

Duration[ms]-6.6E-6(p = .99)-1.6E-3(p = .20)

3.0E-4(p = .73)

8.0E-4(p = .51)

1.8E-3(p = .14)-2.8E-3

7.3E-5(p = .95)

1.5E-3(p = .16)

6.5E-4(p = .60)-3.9E-4(p = .76)

1.0E-3(p = .41)

Duty ratio

0.24(p = .61)-0.50(p = .34)-0.90-9.3E-2(p = .85)-0.26(p = .60)

5.2E-2(p = .92)

-1.3

1.3

-0.17
(p = .75)-0.32(p = .55)-0.41(p = .42)

Triangle-6.0E-20.12(p = 0.84) (p = .65)

-1.5E-17-0.14
0.10(p = .70) (p = 1.0) (p = .62)

0.35
(p = .16)-0.44(p = .12)-1.3E-2(p = .96)

2.0E-2(p = .95)-0.41(p = .18)-0.29(p = .36)

Amplitude -2.1E-3[m/s2](p = .11)

2.3E-33.0E-3-3.1E-4(p = .82)

1.7E-3(p = .16)

5.8E-3

4.5E-3

3.5E-3-8.9E-5(p = .95)

3.2E-3

2.4E-3Frequency[Hz]4.5E-3-6.0E-3-4.2E-3

4.8E-4(p = .78)-5.8E-3-4.0E-4(p = .80)-3.0E-3(p = .06)-3.9E-3-3.8E-4(p = .83)

5.6E-4(p = .74)-1.6E-3(p = .36)

Duration[ms]-1.3E-3(p = .29)-1.8E-4(p = .86)-8.0E-4(p = .44)

8.4E-4(p = .52)-7.5E-4(p = .51)-3.3E-4(p = .74)-6.6E-4(p = .56)

1.0E-4(p = .92)

2.8E-4(p = .83)

1.7E-3(p = .16)-6.8E-4(p = .60)

Duty ratio-0.66(p = .18)-0.60(p = .17)

-1.3

-0.70
(p = .19)

9.2E-2(p = .84)-0.60(p = .16)-0.88(p = .06)-0.46(p = .32)

0.13(p = .80)

0.24(p = .65)

0.93(p = .08)

The cells in orange and gray contain statistically significant values at p < .05 and p < .10, respectively.

Advance Publication

Hikaru HASEGAWA (Non-member)

Ken ITO (Non-member)

Hikaru Hasegawa received his B.S. degree in engineering from Nagoya University. He is currently
a graduate student at Department of Mechanical
Systems Engineering in Nagoya University.

Ken Ito is a mechanical engineer who received his
B.S. and M.S. degrees in engineering from Nagoya
University in 2016 and 2018, respectively.

Shogo OKAMOTO (Member)

Yoji YAMADA (Member)

Shogo Okamoto received his Ph.D. in information
sciences from Tohoku University in 2010. He joined
Nagoya University as an assistant professor in 2010,
and currently is an associate professor at the Department of Mechanical Systems Engineering. His
research interests include haptics, rehabilitationengineering, affective engineering, and assistive robotics.

Yoji Yamada received a Ph.D. from Tokyo Instituteof Technology in 1990. He had been with Toyota
Technological Institute since 1983. In 2004, hejoined Intelligent Systems Research Institute of
AIST as a group leader. In 2009, he moved to
Nagoya Unversity as a professor. He is currently
studying safety and intelligence technology in human/machine systems
and robotic sensing and control for them.