P-2B-19 潜在的な位置の記憶は奥行きを含むか?(2001年度 日本基礎心理学会第20回大会優秀発表賞)

The Japanese Psychonomic Society

NII-Electronic Library Service

TheJapanesePsychonomic Society

7Vze

fiipanese

Joitivaai

of

Ftl,i/h.onouaic

Sciettce

2002,

Vol.21,

No.

1,59-60

Prizewinner's

SummaryP-2B-19

Is

depthimplicitly

encoded

as

visual

Jun-ichiro

KAwAHARA

Hiivshima

Udaiversily'

context?i)

The

spatial

rayout

of objects

can

be

acqulred

implicitly

and

facilitate

visual

search

under

incidental

learning

conditions

(the

contextual cueing effect

_;

Chun

&

Jiang,

1998).

The

_present

study

investigated

whether

the

learned

layouts

are

limited

to

two-dimensional

configurations

or

can

encornpass

three

dimensions.

""e

found

that

the

reaction

tirnes

for

the

repetition

condition

increased

significantly whep

the

disparity

of

the

repeatecl

distracters

was reversed

in

_the

end of

the

session.

These

results

indicate

that

three-dimensiona]

layouts

_can

be

_preserved

_as

implicit

_visual spatial contexts.

Key

words :contextual cueing, visual attentien,

implicit

learning,

stereo

display

Contextual

cueing

is

a

_process

that

_guides

visual

attention

by

enhancing

_the

_processing

of complex scenes.

It

has

been

suggested

that

global

context,

such as

the

]ayout

of

objects,

is

extracted

through

experience

in

a

stable environment.

For

example,

when

_participants

search

for

a

target,

the

visual

search

_performance

is

enhanced

if

_the

spatial

layout

of

items

is

fixed

across

trials

in

comparison

with

layouts

which are randomly

varied

in

every

triar,

This

enhan6ement,

callecl

the

contextual cueing effect,

is

obtained

implicitly.

_The

observers cannot recognise

that

a

specific

set of

layouts

have

been

presented

repetitively,

Researchers

have

shown

that

contextual

cueing

can

be

obtained

with

two

dimensional

(2-D)

spatial

'

outs

(Chun

&

Jiang,

1998).

However

whether

this

effect can

be

obtained with

3-D

displays

has.not

been

examined,

Since

our

living

space

is

not only

2-D

but

contains

3-D

information

abeut

space, we assurne

that

a spatial

context

of

layouts

holds

in

a

3-D

structure.

We

therefore

examined

if

a

3-D

structure

defined

by

'

_Department

of

Psy6hology,

IIiroshima

sity,

Kagamiyarna

1-1-1,

Higashi-hiroshima,

s:r)241)

This

work was sponsored

by

a research

_grant

from

the

Japan

Society

for

the

Promotion

of

Science.

The

author

would

like

to

thank

Hiromi

Hosoda

for

collecting

data.

binecular

disparity

was eneocled as visual context.

The

observers

were

_presented

with visual search

trials,

_In

_the

_OLD

condition,

different

layouts

were

presented

repeatedly.

In

the

NEW'

condition,

a

new

layout

was

_generated

for

each

trial.

In

the

last

set of

trials,

the

disparity

of

the

distractors

in

the

OLD

condition was reversed.

If

the

observers

formed

spatial contexts

including

clisparity,

_then

_the

_learned

layouts

would not

be

consistent with

the

layouts

after

the

disparity

reversal.

The

search

_performance

on

trials

aiter

the

reversal wou]d

therefore

be

_poor

in

comparison with

those

before

the

reversal.

'

Method

Apparatus

a"d

Stimuli

The

stimuli were

dis-played

on a computer rnonitoT which

the

participants

observed

binocularly

_through

_{ferroelectric}

_shutter

goggles.

The

target

a "T" which was rotated

90"

_to

the

left

er

to

the

right.

The

distractors

were

eleven

"L"s

rotated

either

O[,

900,

1800,

or

2700

from

the

upright.

The

stereo

disparity

was

O.5e.

Experimental

Design

and

Procedure

The

design

used

two

within-subject

factors:

layout

(NEW,

and

OLD)

and

block

(1-6).

The

visual search session

hacl

a

total

of

720

trials,

and one

block

consistecl of

120

trials.

In

the

sixth

block,

the

disparity

of

the

dis-tractors

was reversed.

The

recogriition session

contained

24

trials.

The

NEW

condition,

in

which

the

The Japanese Psychonomic Society

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60

The

Japanese

Jeurnalof

Psychonomic

location

of

all

the

items

was

determined

randomly

from

trial

to

trial,

was used

for

half

the

trials.

The

remainder of

the

trials

used

the

OLD

condition.

Half

the

items

were

_presented

in

the

frontal

_plane

and

the

others

were at

the

back,

The

target

was

equally

Iikely

to

be

presented

either

in

frontal

or at

the

back,

and

this

was unpredictable across

trials.

After

the

visual search

session,

the

observers

engaged

in

the

recognition session

that

consisted

of

the

OLD

and

the

NEW

conditions

<12

trials

of

each).

The

ebservers

indicated

whether

they

had

seen

the

display

in

the

visual

search

session,

Sixteen

naive undergraduate students

_{participatecl.}

Refiults

Visual

search

The

mean reaction

times

for

all

ef

the

correct

trials

in

the

OLD

and

the

NEW

conditions,

as a

function

of

a

block,

are shown

in

Figure

1,

A

two-v"'ay

analysis

of varjance was cenducted with

two

within-subject

factor

(layout

:

NEW,

OLD

;

block

:

1-6).

The

analysis revealed

significant

main

effects

of

layout,

F(1,

15)=6S.3,

P<

.OOI,

ancl

block

(F(5,75)==25.0,

P<.OOI),

and

a

significant

interac-tion

between

layout

and

block

(F(5,75)=3,O,

P

<

,05).

To

exarnine

the

effect of

the

reversa] of

the

diparity

'

'

1300

:t!Ig2E

1200

1100

1000

.goe

800

7001

Figure1.

The

rnean

and

OLD

conditions

b]ock,

234S6

BLOCK'

reaction

times

in

the

NEW

,plotted as a

function

of

the

Science

Vol.

21,

No.

1

of

the

distractors,

we conducted a

two-way

analysis of variance

on

the

reaction

tirne

data

of

the

last

two

blocks

with

two

within-subject

factor

(layout

:

NEW,

OLD,

block:

5th

and

6th).

The

analyses

showed

a

significant

main

effect

of

layout

(F(1,15)=63,1,

P

<

.OOI)

,

and

the

interaction

between

layout

and

block

(F(L

15)

=-6.7,

P<

.05)

.

Recognition

Mean

accuracy

in

the

recognition

test

was

50.2%.

Observers

correctly

indicated

the

OLD

layouts

as old on

43.2%

of

trials

(hit

rate)

.

This

rate

clid

not

differ

from

their

false

alarm

rate

of

42.7%

(F(1,15)-1.1,

n.s.).

Discussion

First,

our results

indicated

that

a robust centextual cueing effect was obtained,

Second,

the

results

in-dicated

that

this

knowledge

of spatial

Iayout

was acquired

implicitly.

Most

importantly,

the

learned

layouts

encompassed

three

dimensions.

We

expected a

deteriorated

visual

search

_performance

after

the

reversal ef

the

disparity

of

the

distractors

if

the

visual context

that

_guided

attention

te

the

target

location

was sensitive

to

the

3-D

structure.

The

results

in-dicated

this

was

true,

The

reaction

times

increased

after

the

reversal

of

the

disparity

of

the

distractors,

which

suggests

that

the

visual

context contains

depth

defined

by

stereo

disparity.

The

present

study

revealed

an

anisotropy

ef

spatial

tolerance

in

contextual eueing

in

conjunction

with

previous

studies,

In

terms

of

2-D

coordinates,

Chun

&

Jiang

(1998)

showed robust contextual cueing against

jitters

which were

added

to

the

distractors.

The

reversal of

the

disparity

of

the

di'stractors

introduced

in

the

_present

study can

be

regarded

as

jitter

in

the

depth

clirection,

but

contextual cueing was reduced

with

thisjitter.

The

_present

results suggest

that

the

visual

system

is

capable

of encoding

differences

in

3-D

space as

contextual

cue

and

that

a

generalisation

in

location

may not

be

equivalent

to

spatial

coerdinates.

References

Chun,

M.M.,

&

Jiang,

Y,

1998

Contextual

cueing:

Implicit

learning

and memory of visual

context

guides

spatial attention.

Cagnitive

1]lsychogQgy,

36,