身体近傍から提示される聴覚刺激の触覚弁別課題への影響(第23回大会 優秀発表賞抄録)

The Japanese Psychonomic Society

NII-Electronic Library Service

The JapanesePsychonomic Society

TheJlaPaneseJbumalofk.vehonumicSctence

2eO:r,,VoL24,No.1.121-122

Summaryof

Awarded

PresentationIP53

Tickle

sensationinducedby

hearing

a

soundi

Norimichi

KJTAGAwA*

and

NTT Communication Science

Laboratories*,Yuka

IGARAsHI**

Tohyo

MetroPolitan U}iiversit],**

In

thepresent study we report an illusioninwhich sound _prcsented near tothe head induces

a tactileexperience.

We

stroked the

lcft

ear of a

dummy

head

with a _paintbrush and recorded the

seund and the scene. We thcn _{prcsented the} sound, theimages, or

the

both

to

participants.

The

participantsrated _theirsubjective tactileexperience by answering a _{questionnaire.}

The

results

revealed

that

the participants

felt

a ticklingsensation when the sound was presented near to the

head,butnot when itwas _presented

distant

from

the

head.

Viewtng

thescene had

little

or no effect

on the tactileimpressiQn, The results suggest thataudiotactile

interactions

occur predominantly

in

a region

immediately

surrounding the head,

Key words: multisensory interactions;_ticklesensation; auditory _peripersonal space;

Imagine

amosquito isapproaching _your neck

from

your back.

You

prebabLy notice

it

by

its

flyingsound

and might simultaneously

feel

itchy

on the

_back

of

your neck. This example might imply the existence

of audiotactile

interactions

occurrcd near the

body,

However, while visuotactiIe interactionsin

per{per-sonal space are now well-documented farfewer

stud-ies

have

attempted toexamine audiotactile

interac-tionsin_peripersonal space,

In

the _present study we

report an

illusion

in

which only hearing a sound

induces

a subjective tactileexperience.

Metheds

Fifty students _participated in

this

experimenL

Each _participant was randomly assigned to one of

five

conditions:

A-Near,

AV-Near,

A-Far,AV-Far, and

v.

A microphone, which was

inserted

into

theleftear

of a

dummy

head,recorded thesound as we strokcd

the ear with a _paintbrush, as

if

to

tickle

the ear

(Figure

Ia).

The

scene was also recorded on

video-i _{The title}

_has

_been

_changed

_from

_{theoriginal tit]e}

ofthe posterpresentation

"The

effect of auditory

stimuli prcsented near tothe

body

on tactiLe

criminationperformance,"

* _NTT

_{Communication}

_{Science Laboratories,NTT}

Corporation,

3-1 Morinosato Wakarniya, Atsugi,

Kanagawa 243-0918,

Japan

** _{Department of Psychology, Tokyo Metropelitan}

University,

1-1 Minami-Osawa, Hachioji,

Tokyo

192-0397

tape. We _presented either the sound

(A

condition),

theimages

_(V

condition), or the

both

(AV

condition)

tothe participants

for

30 seconds. The sound was

presented either through headphone$

(Near

condi-tion)or a

loudspeaker

_placed at a

distance

of 80cm

from the _{participant's}

reft

ear

(Far

condition). The

Leq sound

ievel

was measured at

the

leftear and set at

54

dB

(A)

for

each condition.

This

levelwas al-rnost the sarne as _thatof the actual stroke.

After

the presentation of one of _the

five

conditions

theparticipants rated theiragreement with each

sta-tement ofa questionnaire on a

7-peint

scale ranging

from

totallydisagree

₍₁₎

totorallyagree

(7}.

The

questionnaire inc]uded four statements

(see

Figure

1

b).

Statements

1

and

2

related to our

interest

of

whether a tacti]e

impression

was induced by the

sound.

Statement

3 was included to control

for

demand characteristics.

Statement

4

was not

in-cluded in the

A

condition. The sentences were pre-sented one

by

one on a

display

in

a random order.

Results

and

Discussion

The mean ratings in_the

V

condition were smal!

overall, suggesting that viewing the scene of the

tickling

had

little

or no effect on the tactile

impres-sion. Because the mean ratings forall of the state-ments in the

AV

condition were not significant}y

differentfrom thoseintheA condition,

the

data

from

the

A and AV conditions were _pooled so that we

could assess theeffect of _the

distance

factor

on the

The Japanese Psychonomic Society

NII-Electronic Library Service

The JapanesePsychonomic Society

122

The

Japanese

Journal

of

_-

Psvchonomic

Science

V

ol,

24,

No,

1

(a)

_(b)

1.1felttickling onmyownear

･･////t

m

111..tttttttt 2.1feltasifmyown earwastouched ,

l･i･,,g,:a

lt 3.Ifeltasifmyear

ll

wasturningrubberyIi11

-Near{A+AV)

eeFar(A+AV)

pmv

4-S,ff,ita,s,iktZ?e,2r.,

b

wasmyear //////////ttttttttttt//.t/tt////t//t/1/1111 11'1}1l1l +11

Figure

1.

{u)

A

frame

of themovie presented tothe participantsshowing h

the dummy head with a brush. A rnicrophone was insertedintothe ]eftear and recorded _thcsound

the

brush

stroke,

(b)

Questionnaire

results. Each bar indicates_thcmean rating

the Near and Far conditions) or 1O _participants

(in

th

va]ues are indicatedwith asterisks

<*

p<O.1;

**

p<

O.05;***p

1234567

Totallydisagree Tetallyagree ow we stroked

the

left

ear of

of

of 2Q participants

(in

e

V

conditien} with standard errors.

Significance

<O,Ol;Tukey'sHSD).

tactileimpression

{Figure

lb).

A two-way ANOVA of the rating data,with

thc

between-participants factoruf the presentation

con-dition

_(Near,

Far,

and

V}

and the within-participants

factor

oi the four statements, reveared significant

main effects of

the

_presentation condition

[F(2,

47>=

6,06,

P<O.O1],

and ot thestatements factor

rF(3,

121) =23.21,P<O.OOI]. There _{were also significant}

inter-action

between

them

[F(6,

121)=4.56,p<O.OOI].

The

participants inthe Near condjtion responded more

positivelythan the participants in the Far and V

conditions to

the

statement 1,

Similar

_trends wcre

observed for thestatements 2 and 4,

but

not

for

the

statement

3

as expected. These results suggest that

sound _presented close to the head could inducc a

tactileimpression, but sound _prc6ented at some

dis-tance

from

the

head

could not,

One may argue thatirnagcry ¢euld be involved in

thc

phenomenon,

That

is,

when the participants

heard

the sound, they

imagined

a situation

in

which

they werc tickledby something and they inturn felt

ticklingon theirear. However none of the

partici-pants in thc

A

condition was aware of what the

sound was, and so they could not

imagine

such a

situation.

Therefore

irnagery

cannot fullyexplain

this

illusion.

Our results suggest thata ticklescnsation, thathas

to

date

been

censidered unique tothesomatosensory system

(e.g.

Stein & Mcredith,

1993),

in fact can occur

from

hearing

a sound

delivered

near to the

head.

Our results also _provide support fortherecent

suggestion, based on _{psychophysical}

(Kitagawa,

Zampini, & Spence, in _press>,neurophysiologica]

(Graziane,

Reiss,

&

Gross, 1999) and

neuropsycho-logicaldata

(Farnb

& Ladavas, 2002),that

audiotac-tilespatial interactionsoccur predominantly

in

the

region immediately surrounding the head

(Le.,

peri-head

space).

References

Farne,

A.

&

Ladavas,

E.

2002 Auditory peripersonal

space inhumans,

_lburnat

_of

CognitiveIVeuroscienee,

14,

1030-1043,

Graziano,M. S,A,,Reiss,L.

A

J,,

&

Gross,

C.

G.

1999

A ncuronal representation of the

]ocation

of

by sounds.

Alature,

397,

_428-430.

Kitagawa,

N.

Zampini,

M.,& Spence, C. inpress

diotactile

interactions

innear and farspace.

EttPeri-mentat BrainResearch,

Stein,

B.

E.

&

Meredith,

M.

A.

1993

The

meTging

of

the