1P080 周辺手がかりの効果における初期視覚的要因の影響(2003年度 日本基礎心理学会第22回大会優秀発表賞)

The Japanese Psychonomic Society

NII-Electronic Library Service

The JapanesePsychonomic Society

ThekuaneseJeu･rnatofFkychetmmicScience

2004,VoL23,No.1,99-100

Summary

ofAwarded

PresentationIP080

Low-level

Shigekazu

The

visual

interaction

in

the

effect

of

_peripheral

cuing

'

TAKEi*･**,

Tatsuto

TAKEucHi**,

and

Kazuhiko

YoKosAwA*

Univet:sibs

_of

Tokyo* and NTT Communication ScienceLabvratories**

Presenting a precue near the

location

where a targetwill appear causes an enhancement of

visual _{performances.} This _procedure iscalled _peripheralcuing, and the effect of _pcripheraLcuing

has been interpretedas a resutt of an allocation of covert attention. However, a low-levelvisual

interaction

between

thecue and thetargetcan enhance representation of thetargettoinduce the

cuing effect.

We

examined whether the effect of _peripheralcuing

is

due

toan attentional process,

or

to

a

low-]evol

visual interaction,

To

do

this,

we compared conditions with similar visual

interaetions,

but

with attent[on al]ocated

different]y.

In one condition, we _presented the firstcue

near the targetand the second cue distantfrom the target,todeprive attention

from

the target

location,Inanother condition, asing]e cue was _presentcd ncar thc _targettoalloeate attention at the

target.

We

found

thatthe accuracy of

discriminating

the tiltof a targetwas

low･

er

in

the

cendition

which attention was deprived,This result suggests thattheeffect of peripheralcuing

is

due

toan

attentional _process.

Key

words: covert attention,

feature

search, _peripheralcuing, visual

interaction

When a _precue,such as a small circle, is_presented

at a targct position

before

thc onsct of the target.

detectabilityand discrirninablityof the target are

rnore irnproved than when the _precuc docs not

indi-cate thetargetposition

(e.g.

Posner,

1980}.

This

type

of _precueiscalled a _peripheralcue, and the

improve-mcnt

induced

by

the

_pcriphera]cuing

has

bcen

as-sumed to

be

a

function

of covert visual attention.

It

isassumed thatan abrupt onset of the

_precue

_guides

attention involuntarilyto the cued location.

There-fore

theperformance of the visual task

is

rnore

im-proved when attention

is

guided validly than

inval-idly.However, _presenting a _preeue sheuld cause an

enhancement or inhibitioneffect between the cue

and thetargetas a consequence of the

lateral

interac-tionsbetween spatial filters.This low-levelvisual

interaction

can explain the

improvement

induced

by

the peripheral euing, In thisstudy we examined

whether an attentional _process or a low-levelvisual

interactioncauses _theeffect of _peripheralcuing.

*

_Department

_of

_Psychology,

_Graduate

_School

_of

Humanities and Sociology,The Universityof

kyo, 7''3-1Hongo, Bunkyo-ku, Tokyo 1I3'O033

** _{NTT Communication Science Laboratories, 3 1}

Morinosato,

Wakamiya,

At$ugi

243-O198

Method

Three naive subjects participated in the

experi-ment. The stimuli were disp]ayed on a CRT monitor

and centrolled

by

MATLAB

and

Psych

Toolbox

on an

Apple PowerMacG4,

We

used the

feature

search

task,

The subjects reported the orientation of the

target

(right

or leftfrom the vertical) embedded in

the vertically oriented seven

distractors.

We used a Gabc)rpatch

for

thestimuli.

The

con-trastand theorientation of the stimuli were adjusted

for

each subject

in

a pilot experiment

in

order to

keep the highest accuracy at 80-85%. The contrast

ranged from 10 to 40% and the orientation was

about

100,

The

Gabor

_patches subtcnded 1.7U. A

black circle _precue subtended O,70.

The

fixation

point was always _presented at the

center of the

display,

The

stimuti were _presented at eight equidistant locations

from

the

fixation

pointat

2.50eccentricity. The distances between the

neigh-boring

stirnuli were the same. The target _position

was randomized

in

each triaL

There were four cuing conditions

(Figure

1(a)).In

the peripheral-central

(P-C)

condition, the firstcue appeared beside the targetpositionand the second

cuc wa$ _presented at the central fixation

point,

ln

The Japanese Psychonomic Society

NII-Electronic Library Service

The JapanesePsychonomic Society

1OO The

_Japanese

_Journal

of

Psychonomic

Science

VoL

23,

No.

1

{a)

.ptgeem.

rwes.

ttt.t

ff

ttttt

l tSee,

peflpherel pef/pheral periphernl

X

X g.Cerit7tl

peripher:1

.-l,,;l:tll･

l

Figure 1.

(a)

A schematic descripLionof a sequence in

of

the

cue shift.

<b)

The mean accuracy of 3subjects,

(b)

go

g

sotr:8

70<60

50one

trial.Dashed arrows reprcscnt thedirection

The error bars represent ±1

SE.

condition, was _presented. Sincetheduration of pres-entation and the _position of the firstcue were the sarne forthe two cuing conditions a sirnilar visual

interaction

was expected,

However,

if

the cuing

effect was due toan attentional process,target

dis-crimination inthe P-C condition would beless

accu-rate as a result of attention being pulledaway from

the target _positionby the onset of the second cue,

There remained a _possibilitythat the motion

in-duced

by

sequential _presentation of two cues might

mask theperception ef thetarget,and

it

might result

in

a

lower

accuracy

in

the

P-C

condition.

In

ordcr to

evaluate such a masking effect,

the

first

cue was

presented at the same _positionas the firstcue inthe

P-C condition and thesecond cue was presented on

thc opposite side of the target

in

the

peripheral-peripheral

(P-P)

condition. Inthe

P-P

6onditien

at-tention should be allocated around the target

posi-tion.Therefore,iftheaceuracy of target

discrimina-tion was

lower

in

the

P-P

condition

than

in

the

peripheralcondition, thiswould bedue toa masking

effect and not toinattention.Inthecentral condition

only the

first

cue was presented at the

fixation

point.

After

800

ms

from

the start of a trial,the

first

cue

was _presented for59ms. Afteran ISIef 11.8ms, the

second cue was _presented for 59ms. The cuing

periodwas fellowed by 11.8ms of ISIand the stimuli

were presented for59 ms. Randorn-dot postmasks replaced the stimul{, and

disappeared

when a

re-sponsc was made.

Because

the

interval

between

the

cue onset and thestimulus offset was within

25e

ms, we assumed that eye movements didnot occur whi]e

thestimuli were presented.

Results

and

Discussion

The

averaged accuracy of threesubjects isshown

in

Figure

1(b).

The

lower

accuracy in

the

central

cuing condition suggests that _presenting a _precuc

near the targetimproved the discrimination of the

orientation

A

one-way

ANOVA

of thethreecue types

(P-C,

P-P, and periphera]} revealed a main effect of

cue types (x2

<2)==

14,73,p<,05),

A

post-hoc testby

Ryan's

procedure revealed

that

the

accuracy of

the

P-C condition was significantly lower than the accu-racy intheother conditions,

The results suggcst thatthe deteriorationof target

discrimination

in

the

P-C

condition can not

be

ex-plained

by

a

low-level

visual

interaction

or a

mask-ing effect, Based on a low-levelvisual interaction,

differenceswould not beobserved between the cuing

conditions. Based on a masking effect, theaccuracy would be lowerintheP-P and P-C conditions than in

the_peripheralcondition.

However,

only accuracy

in

the

P-C

condition was

lower

than

the

other cuing conditions.

Therefore, we conclude that the deter{orationin

the P-C

_Fondition

reflected an attentional _process,

The abrupt onset of thesecond cue distantfrom the

targetrnight deprive attention

from

the target,

The

present experiment

indicates

that a _peripheralcue

can guide covert attention which

improves

a

repre-sentation of visual stimuli,

References

PQsner, M. I.1980 Orienttng of attention, The