Liquid Attention : The effect of contour on attentional spreading(Summary of Awarded Presentation at the 29th Annual Meeting)

The Japanese Psychonomic Society

NII-Electronic Library Service

The JapanesePsychonomic Society

The

jdpanese

Jbut7iat

ofRsychonemic

Sctence

2el1, VoL 30.No. 1,131-l32

Summary

ofAwarded

Presentation1-302

Liquid

The

effect

of

contour

Attention

on

attentionalspreading

Kazuki

IKEGAME

and

Chikashi

MIcHIMATA

SQPhia

Uhiversity'

It

has

been

suggested

that

visual attention spreads

along

an

objecVs

contour.

We

investigated

the

role

of

contour

on attentional spreading,

As

an

index

of

spreading,

we

applied

the

same-object

ofect,

where observers

respond

faster

to

targets

within

cued objects

than

those

within uncued objects.

The

stimuli

consisted

of

two

rectangular

objects,

both

of which were missing one

long

side.

The

task

was

to

detect

a

target

that

appeared at

the

end

of

either

a

cued

or

uncued

object.

In

both

Experiments

1

and

2,

the

same-object

effect was

decreased

when

the

cued object was missing

the

side

faced

the

uncued

object.

Moreover,

this

tendency

was more obvious when

the

uncued

object was atso missing

the

side

faced

the

cued object,

These

results

suggest

that

attention

spreads

frorn

the

opening

of

the

cued

object

to

the

uncued object,

like

a

"liquid,"

Key

words: object-based attention, same-object effect,

attentional

spreading,

contour

Ourvisual

attention spreads automatically

over

an

attended object.

That

is,

when we

perceive

that

a

spatial

location

is

within

the

attended object, we can respond

faster

to

it

than

to

the

location

within

the

other, unattended object

(same-obl'ect

op7ect,

Egly,

Driver,

&

RafaL

1994).

Marino

and

Scholl

₍₂₀₀₅₎

showed

that

thi$

effect

decreases

when

the

two

pairs

of

parallel

lines

are

substituted

for

the

two

rectangles usually used

in

this

paradigm.

It

suggests

that

attention

spreads

along an objecVs contour and "leaks"

from

the

open-ing

of

the

object.

In

this

experiment,

we

investigated

the

role

of

contour

on

attentional

spreading.

Experiment

1

If

attention

leaks

and spreads

frorn

a centour-missing

location,

the

same-object effect would

be

de-creased when

both

objects'

inner

contours were

de-leted

(hacing

condition,

Figure

1(a)).

On

the

other

hand,

the

effect would

be

increased

when

the

objects' outer

contours

were

deleted

(Backing

condition,

Figure

1(b}).

Method.

Forty-four

students

_participated

in

this

experiment.

The

stimuli

consisted

of

two

rectangles

of

11.4D

×

1.70,

and

each

rectangle's

long

side

was

deleted

as shown

in

Figures

1(a)

and

<b).

The

two

objects

spanned

the

fixation

_point

either vertically

or

horizontally.

The

task

was

te

detect

a

target

{black

square)

that

appeared at

the

end of

one

object

after

a

flash

cued

the

targeVs

appearance.

The

target

ap-peared

at

the

cued

end

(Valid:

V),

the

uncued

end

within

the

cued

object

(Invalid

Same:

IS),

or

the

uncued

end within

the

uncued object

(Invalid

Dif-ferent:

ID,

see

Figure

1(c)).

The

experiment

was a

within-participants

design

that

included

two

factors:

Object

direction

_{(FacingfBaching)}

and

Target

loca-(a)

(d)

sll

*

_Department

_of

_Psychology,

Human

Sciences,

Sophia

Kioicho,

Chiyoda-ku,

Tokyo

+

+

(b)

(e)

Nl.t

"

+

(c)

slt v IS+ID

Graduate

School

of

University,

7-1

102-8554,

Japan

Copyright

2011.

The

Japanese

Psychonomic

Society

Figure

1.

Stimuli

presented

in

Experiments

1

and

2.

In

Experiment

1,

The

Facing

condition

(a}

was compared with

the

Backing

condition

(b).

In

Experiment

2,

LAM

(Look-at-me)

condition

(d),

in

which

only

the

ctted

object

faces

to

the

other, and

DLAM

at-me)

condition

(e),

in

which

only

the

uncued

obl'ect

faces

to

the

other

were

compared.

In

all

conditions,

the

target

appeared at

the

following

locations

after

the

cue:

Valid,

Invalid

Same,

or

Invalid

Different

(c},

The Japanese Psychonomic Society

NII-Electronic Library Service

The JapanesePsychonomic Society

132

The

_Japanese

_Journal

of

Psychonomic

Science

Vol,

30,

No,

1

Table

1.

Reaction

time

and

the

same-object advantage

in

experiments

1

and

2Mean

RT

_<ms)

ConditionVISID

Same-object

advantage

(ID-IS)

Exp.

1FacingBacking308

₃₀₉

340

₃₃₅

341

₃₄₅

110***

LAM

Exp.2

_DLAM

304

₃₀₄

333

₃₂₉

338

₃₃₇

58*

**\<.OOI,

fp<.05

tion

(rs/M).

Results

and

Discussion.

The

mean

reaction

times

(RTs)

in

trials

in

which

the

target

appeared at a cued

location

₍₃₀₉

ms> were shorter

than

those

in

trials

in

which

the

target

appeared

at

an

uncued

location

(340

rns,P<.OO1).

This

means

that

the

cue captured

atten-tion

efficiently.

The

RTs

were

also

analyzed

by

means

of

two-way

ANOVA.

This

analysis revealed a

main

effect

of

target

Iocation

(IS:

338

ms

vs.

ID:

343

ms,

F(1,43)=5.882,

p=:.020),

which

indicated

the

presence

of a same-object effect.

Moreover,

a

two-way

interaction

was

also

observed

(F(1,

43)=6.481,

p==.O15),

which

means

the

magnitude

of

the

same-object

effect

(the

same-object

advantcrge)

was

sig-nificantonly under

the

Backing

condition

(IS:

335

ms

vs.

ID:

345

ms,

_P<.OOI,

Table

1).

These

results

sug-gest

that

the

presence

of

contours

affects

attentional

spreading.

Experirnent

2

There

is

a

possibility

that

the

two

objects

used

in

the

Facing

condition

in

Experiment

1

were

seen

as

"one"

object.

To

rule

out

this

possibility,

we

added

two

conditions

<Looh-at-me

condition:

LAM,

and

Don't-loole-at-me

condition:

DLAM,

Figures

1(d)

and

(e>)

in

which

the

obj

ects'

contours

were

deleted

on

the

same

side,

The

difference

between

these

conditions

was

the

direction

in

which

the

cued objects

faced.

'

Under

the

LAM

condition,

the

cued

object

faced

'

toward

the

uncued

object while

the

uncued

object

faced

away

from

the

cued

object,

In

contrast,

under

the

DLAM

condition

the

cued object

faced

away

from

the

uncued

object,

Because

both

conditions

used

the

same

_physical

stimulL

the

difference

be-tween

conditions

in

the

magnitude

of

the

same-object

advantage

between

conditions

would

rule

out

the

_possibility

of

"perceiving

one

object"

in

Experi-rnent

1.

If

attention

spreads

from

contour-missing

!ocations,

the

same-object

effect would

be

decreased

in

the

LAM

condition

because

attention

to

the

cued object could easily

spread

toward

the

uncued

object.

Method.

Forty-three

students

_participated

in

this

experiment.

The

design

included

_two

factors:

Object

direction

(LAM/DLAM)

and

Target

location

(ISIID),

The

method was

identical

to

Experiment

1.

Results

and

Discussion.

Similar

to

Experiment

1,

the

cue

capturecl

attentien efficiently

(cued

locatien:

304

ms vs. uncued

location:

334

rns).

While

ANOVA

revealed a rnain

effect

of

target

_location

_(IS:

₃₃₁

ms

vs.

ID:

337

ms,

F(1,

40)

==

12.663,

p=.OO1>,

_no

interac-tion

was observed

to>.40),

However,

the

difference

between

target

location

conditions

was significant

only

in

the

DLAM

condition

(IS:

329

ms vs.

ID:

337

ms,

_p=.O18,

Table

1).

These

findings

suggest

that

attention

spread

from

the

object's

opening

and

that

the

location

of

the

opening

in

the

attended object

was

important

for

spreading

to

the

other

object.

General

Discussion

Our

results suggest

that

visual

attention

spreads

from

the

opening

of

the

cued object

to

the

opening of

the

uncued

object,

Moreover,

a

comparison

of

same-object advantages among

four

conditions

in

two

ex-periments

showed

that

the

size

of

the

advantage

depended

on

the

number

of

inner

contours

of

each

object

(Table

D.

Thus,

attentiona] spreading

is

possi-bly

affected

not

only

by

location

but

also

by

the

number

of

contours

that

inhibit

the

spreading.

Con-sidering

these

results, visual attention

to

the

object

appears

to

have

the

characteristics

of

a

liquid:

it

leaks

and spreads

from

the

attended object

References

Egly,

R.

Driver,

J.

&

RafaL

R.

D,

(1994).

Shifting

visua] attention

between

objects and

locations:

Evidence

from

normal and

_parietal

lesion

subjects.

fournal

of

EtPerimentat

Rsychogogy:

General,

l23,

161-177.

Marino,

A.

C.

&

Schol],

B.

J.

(2005).

The

role of

closure

in

defining

the

"objects"

of

object-based

attention.

Iiercoption

&

Psychophysics,

67(7),

1

140-1

149.