Time perception is influenced by the subjective area size of a brief stimulus(Summary of Awarded Presentation at the 25th Annual Meeting)

全文

(1)

The Japanese Psychonomic Society

NII-Electronic Library Service

The JapanesePsychonomic Society

TheJapaneseJbTirnat of i]s.vchonomic Science

2007,N,o].25,No.2,277-278

Summary

ofAwarded

PresentationIP37

Time

perception

is

area

size

influenced

by

the

of

a

brief

stimulussubjective

Fuminori

ONo*

and

Jun-ichiro

KAwAHARA**

luntendo

University*,IVdtionatInstitute

of

Advanced

industrialScience and Technology**

Ono

and Kawahara

(2006)

have reported that when theapparent size of a visual object inthe

Ebbinghaus

illusionwas overestimated

its

perceived duration was longerthan when

it$

size was underestimated,

Because

the time estimation task and the sizeestimation task were presented consecutively

in

theirstudy, theparticipantsmight

have

estimated thearea size

during

thetime

estimation task.Inthe presentstudy the timeestimatjon and $ize estimation taskswere conducted

inseparatc

blocks.

This

procedure was used todetermine whether theeffectof apparent visual size

on the perceived

duration

was because

the

subjective area size was altered by the

illusion,

or

whether itwas an artefact caused by theparticipantsengaging in

the

sizeestimation task.

The

results

indicated

that the perceived duration of apparent]y largestimuli was longer than thatof

apparently small stimuli, even

if

the participantswere not engaged

in

thesizeestimation task,and revealed that time pcrception is

influenced

by

subjective area size,

Key words: time perception,subjective area size, Ebbinghaus

illusion

The

perceived

duration

of events isaffected bythe

non-temporal attributes of stimuli, such as the

num-ber

of components. size,or complexity. Presenting a

large

quantity of stimuli to an observcr tends to result

in

an overestimated duration. Although

previ-ous studies have suggested that time perception

is

infiuenced by the physicalattributes oi stimuli, itis

not known whether time perception isinfiuencedby

differences

in

the subjective appearance of physi-cally identicalstimuli.

Recently we

investigated

(Ono

&

Kawahara,

2006)

the effect of subjcctive size on time perception. Our study combined the visual area-size effect on time

perception

{Thomas

&

Cantor,

1975)

and the

Ebbing-haus illusionfigure. In the

Ebbinghaus

illusion

figure,

a central circle which

is

surrounded by large

inducers appears tobesmaller than a central circle of

the same sizewhich issurrounded by small inducers.

We

measured the perceived

duration

of

the

visual

circles when the apparent area sizeof the circles was altered by the Ebbinghaus illusion.

Our

re$ults

indi-cated that theperceived duration of the apparently

largecircles was longerthan thatof apparently small

* Department of

Neurophysiology,

School

of

Medicine, Juntendo University, 2-1-1 Hongo,

Bunkyo-ku,

Tokyo

113-8421

Copyright2007.

circles, even though the actual area size remained

lnvanant,

Inthe

Ono

&

Kawahara

(2006)

study however, the

time estimation task and thc size estimation task

were presented consecutively.

The

participants

thereforecould have estimated the central area size

during the time estimation task. Ifthiswere thecase, the observed effect of apparent size on perceived

duration

might have been due to contamination by

the size estimation,

Consequently

in

the present

study we ran the time estimation and size cstimation

tasks in separate

blocks,

Ifthe variations of the

perceived

duration

were due toerrors of size

estima-tion rather than of time perception, then the per-ceived duration of the subjectively

large

condition would

be

the same as thatof the subjectively small condition,

Alternatively,

ifthe apparent area size

infiuenced

time perception, even when the

partici-pants were not engaged inthe size estimation task,

thepercejved duration of thesubjectively

large

con-ditionwould

be

longer

than thatof thesubjectively small conclition.

Method

Participants

Twenty

experimentally naive

stu-dents

from

Hiroshima

University

volunteered as

$ub-jects,

and received either a course credit or pay.

(2)

The Japanese Psychonomic Society

NII-Electronic Library Service

TheJapanesePsychonomic Society

278

The

Japanese

Journa]

of Psych

Stimuli

The

stimuli wcre black circles presented on a gray

background,

There

wcre two conditions: subjectively small and subjectively large.Four

sur-rounding

induccr

circles were displayed on thelefL right, top,and bottom, of the central circ]e. The

diameter

of theinduccr circles was

4

degrees

in

the subjectively small condition, and 1 degree in the

subjectively

large

conditjon.

In

both

conditions the

diameter of thecentra] circle was 2degrees.

Procedure

The

experimcnt included training,

time estimation, and size estimation

block$.

In

the

training block only the central circle was displayed

for

one of

four

durations

(l

OO,

200,3eO,or 400 ms)

in

a random order.

The

participants categorizcd the

duration

bypressingone of fourkeys

<1

for

short and

4 iorIong).

After

60

training trialsthe participants

performed

120 time estimation trials.

In

each of the

trials onc of two types

(the

subjectiv・ely large or

small condition) of surrounding circles was

ran-domly displayed for 1500ms and a central circle

appeared

for

either

150

or

350

ms. The participants

categorized the displayed duration of the central circle

by

pressing one of four keys. After the time

estimation

block

(120

trials),the participantswere

given

instructions

for

thesize cstimation task. The participant,swere not told toestimate the area size of

the circle until they were givcn this instruction.In the size cstimation

block

{40

trials),the same se-quence of events as inthetimc esLimation

block

was

presented again, and then eight types of variously

sized comparison circles were displayed. From the

eight alternatives the participantsselected a circle whose area was perceived as

identica]

tothecentral circle by pressing one of eight

keys

{1-8).

Results

and

Discussion

The mean of the time estimation and size

estima-tion

for

each subjective sizccondition ispresentedin

Tab}e 1. An analysis of variance

(ANOVA),

with

Subjective

Size

{subjectively

small or subjective]y

large)and Duration

(150

or 350 ms) as within-subject variables, revealed significant main effects of both variables: SubjectiveSizc,F{1,19)=5.97,P<.05; and

Duration,

F(1,

19)=504.82,p<,OOI.

The

lnteraction

onornlcScience Vol.25,No. 2

Table

1

The mean of the time and sizeestimation tasks.

The standard deviation is

in

parentheses.

Tirneestimation

Size

estimation

Subjec-tively

small

Subjcc-tively

large

Subjec-tively

small Subjec-tivcly large 150ms 1.53C25) 1.54{,24) 2.86(.55) 3.80C89)

350ms

3.14C29)

3,26C27>

2.90(.80)

3.91C82)

betwccn thevariables was significant,

F(1,

19)=5,99,

p<.05.

It

isjmportant tonote that themain effect of

Subjective

Size

indicated that the time perception

was infiuenced by the subjective area size.

An

ANOVA

with SubjectiveSizeand Duration as

with-in-subject

variables revealed asignificant main effect

oi the SubjectiveSizecondition, F{1,19)=35.80,p<

,OO1,

The

main effect of the

display

duration,

and the

interaction

between

Subjective

Size

and Duration,

were not significant, F(1,19)=O.32,

p7:.57.

The analysis of SubjectiveSizesuggested thatthe

appar-ent area sizeoi thecentral circle was changed due to the

Ebbinghaus

Musion.

In conclusion, the present study examined the

effect of theEbbinghaus illusionon time perception

(Ono

&

Kawahara,

2006)

by

running thetime estima-tion and sizc estimation tasks

in

separate

blocks.

There

were

two

major results. First,the novel

find-ing

frorn

Ono

&

Kawahara

<2006}

was clearly

rep]i-cated, confirrning that the perceived duratjon of

ap-parently

large

stimuli was

longer

than thatof

appar-ently srnall stimuli. Second, theresult eliminated the

possibilitythat theirfindingwas an artifact caused

by

running the sizc estirnation

task

consecutively

with the time estimation task:the effect was

repro-duced even when participantswere not engaged

in

the size estimation task.

References

Ono,

F.& Kawahara,

J.

2006

The

effect of subjective

area size on time perception. The

joPanese

.lburnal

of

Rsychonomic

Science,

25,

1

19-120.

Thomas,

E,

A,

C,

&

Cantor, N.E.1975

On

theduality

of simultaneous time and size perception.

Updating...

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