• 検索結果がありません。

Cortical distribution of asymmetric responses to radial expansion/contraction in human adults and infants(Summary of Awarded Presentation at the 27th Annual Meeting)

N/A
N/A
Protected

Academic year: 2021

シェア "Cortical distribution of asymmetric responses to radial expansion/contraction in human adults and infants(Summary of Awarded Presentation at the 27th Annual Meeting)"

Copied!
2
0
0

読み込み中.... (全文を見る)

全文

(1)

The Japanese Psychonomic Society

NII-Electronic Library Service

The JapanesePsychonomic Society

The

YnPanese

Jburnal

of

Rs}/chonomic

Sctence

2009,

Vol,

28,

No.

1,

175-l76

Summary

ofAwarded

Presentation2P37

Cortical

distribution

of

expansion/contractionasymmetric

responses

in

human

adults

and

to

radial

infantsi)

NobuSHiRAi*'

t,

Tomoko

IMuRA*2,

Deirdre

BiRTLEs*3,

Shirley

ANKER*3,

Shigeru

IcmHARA*,

John

WATTAM-BELL*2,

Janette

ATKiNsoN*3,

and

Oliver

BRADDicK*4

7bkpuo

Metropogitan

Uitiversity*,

Primate

Research

institute,

Klyoto

Ubeiversily*2,

Uitiversity

Collage

London*3,

Uitiversily

of

drford*`

The

distribution

of

cortical activity

to

radial expansion or contraction motion with adults and

infants

(3

to

4

months

and

4

to

5

months

of

age)

was

examined

by

measuring

steady-state visua] evoked

potentials

with a

high-density

electrode array.

A

motion

pattern

which was

either

radial

expansion

or

contraction

was alternately

presented

with

a

pattern

of

random motion,

and

the

mean amplitude of

the

fundamental

harmonie

cornponent

<Fl)

corresponding

to

the

pattern

alternation

frequency

{2

Hz)

was

measured.

The

result$

iridicated

the

adults

showed

greater

activity

to

contraction

than

to

expansion

in

the

right

parietal

area.

Although

the

older

(but

not

the

younger)

infants

also

showed

contraction

bias,

the

bias

was

spread

over

the

whDle

oecipitoparietal

area,

These

results

suggest

that

in

adults

radiaL

motion

processing

may

be

achieved

by

different

neural mechanisms

to

those

in

infants.

Key

vvords: radia] expansionlcontraction, visua] evoked

potentials,

asymmetry,

cortical

tion

A

previous

study

indicated

that

significant cortical activity

to

radial expansion or contraction motion, a

critica] cue of

motion

in

perception

of

depth

and self-motion, emerges at approximately

4

months of

age

(Shirai,

Birt]es,

Wattam-Bell,

Yamaguchi,

Ka-nazawa,

Atkinson,

&

Braddick,

tn

press).

Hewever

it

is

still

unclear

whether

infants'

cortical

responses

to

radial

motion

are

comparable

to

those

of

adults.

We

investigated

this

topic

by

measuring

the

cortical

dis-trib'ution

of

activitv

associated

with

radia]

motion

processing

in

human

infants

and adults.

Method

Participants

Twelve

infants

aged

3

to

4

months

(mean

age==106.9

days,

SD=

±

8.8)

and

17

infants

t)

This

research was supported

by

Research

Grant

G0601007

frorn

the

Medical

Research

Council,

and

grant-in-aid

for

scienttfic research

from

the

Japan

Society

for

the

Promotion

oi

Science

<19-1464)

t

The

corresponding author,

N,S.,

is

currently

with

Department

of

Psychology,

Niigata

versity,

2-8050

Ikarashi,

Nishi-ku,

Niigata-city,

Niigata

950-2]

81

E-mail.shirai@human.niigata-u,ac.jp

aged

4

to

5

months

(mean

age=139.5

days,

SD=

±

11.7)

participated.

They

were

healthy

full-term

in-fants

and

born

within

14

days

from

due

date.

The

infants

did

not

have

any strabismus or signifieant

refractive

error,

Twenty

adults

(mean

age='

24.5

years,

SD

= ±

6.2)

also

participated

and

were

tested

in

the

same

way

as

the

infants,

Stimuli

Dynamic

dot

patterns

which

alternated

between

radial expansion

(or

contraction) and

ran-dom

motion

were

used

as

stirnuli.

The

alternatien

occurred

every

250

ms

(2

Hz

in

temporal

frequency),

Each

dot

pattern

consisted

of

2000

white

dots

(clot

diameter=O.37deg)

distributed

on

a

black

fie]d

(width=49

deg,

height=37

deg).

The

dots

moved at constant speed

<6.8degfs),

There

were

two

experi・

mental

conditions:

the

expansion

condition

(expan-sion

vs.

random

alternation)

and

the

contraction

con-dition

(contraction

vs. random alternation),

Apparatusandprocedures

Thestimuliwerepre-sented on a

17-inch

CRT

monitor with a refresh rate

of

60Hz,

a resoluZion of

1,024

×

768pixels,

and a

viewing

distance

o'r

40

cm.

The

visual evoked

poten-tials

were

recorded

with

a

high-density

128

channel

EEG

recording

system

(Electrica]

Geodesics,

Inc.,

EGI

Copyright

2009.

The

Japanese

Psychonomic

Society.

All

rights reserved.

(2)

The Japanese Psychonomic Society

NII-Electronic Library Service

The JapanesePsychonomic Society

176

The

Japanese

Journal

of

Psychonomic

Science

Vo],

28,

No.

1

(a)"lS

O.8'・"vev=

O,6nt'g,.,:EO

O.2

÷

1

+r

l,

"tfpi..

T

.-x'l

".

.1..,tt./t

'.F

;i

';

't" "r. +4me: Contrection/

i/ltt・:;TT":''epa,".:.rilcO.tlonil

(b)

e.sS

e.4}g

= O.3L-=-nE as 02xEg o.1s-t.

i

Ilti

itT

o・

e'

:X2s68S

aab tu"

:xks6S

ge

2

Eiectrecie

Electrede

Figure

1.

{a)

Results

of

the

3L4

(open

symbols)

and

4-5

(filled

symbols) month-o]ds.

Cb)

Results

of

the

adults,

In

both

figures,

triangles

and

circles

represent

the

results of

the

expansion

and

contraction

conditions,

respectively.

Error

bars

show ±

1

SE.

;

'ti

[til$:glaontvepsu

/-R

300

system

with

HydroCel

Geodesic

Sensor

Net

128),

A

small noisy

toy

was

presented

in

front

of

the

infant

to

attract

their

attention

to

the

monitor,

Each

experi-mentaL session consisted of

20

sweeps of radial-random motion

aLternations.

Ten

sessions

ran

for

each

experimental

condition,

so

that

waveforms were averaged across a

total

of

200

sweeps

in

each

experimental

condition.

The

amplitude

of

the

signal

component at

the

pattern

alternation

frequency

(Fl)

was measured

frem

9

occipitotemperal

e]ectrodes

at

the

positions

P5,

P7,

P07,

Ol,

Oz,

02,

P08,

P8,

and

P6,

with a reference electrode at

Cz.

Results

and

Discussion

Figure

la

dlspLays

the

results

obtained

from

the

infants.

A

three-way

ANOVA

(ageXmotion

direction

Xeleetrode),

with corrected

degrees

of

freedom

by

Huynh-Feldt's

method, revealed

that

the

main effect

of

age

and

of

electrode

were

significant

(F(1,

27)=:

8.72,

p<O.O06;

F(5.47,

147.7>='8,43,

p<O,OOI).

The

signthcant rnain effect of age $uggests

that

the

corti-cal activity

to

radial motion

patterns

increases

be-tween

3

to

4

and

4

to

5

months of age,

The

interac-tion

between

age

and

motion

direction

was

also

sig-nificant

(F(1,

27)=

6.28,

p<O.02>.

A

Tukey

post

hoc

comparison revealed

that

the

mean

amplitude

was

significantly

larger

in

the

contraction

condition

than

in

the

expansion condition

in

the

older

group

(p<

O.05).

This

corresponds

te

a

previous

finding

that

a

contraction-biased

cortical

activity

emerges

around

4

months of age

(Shirai

et al,,

in

press).

Figure

lb

illustrates

the

results obtained

from

the

adults.

A

two-way

ANOVA

(motion

directionXe]ec-trode},

with corrected

degrees

of

freedom

by

Huynh-Feldt's

method, revea],ed

that

the

main effect of

elec-trode

and

the

interactions

between

the

two

factors

were significant

(F(3.08,

58.55)=13,31,

p<O.OO].;

F

(4.01,

76.27)=

4.20,

P<

O.O04).

A

Tukey

post

hoc

com-parison

revealed

that

the

difference

between

the

ex-pansion

and

contraction

conditions

was

(marginally)

stgnificant

only

in

the

right

parietal

electrodes

P8

(p

<O,02}

and

P6

{P<O,06),

The

results

from

the

infants

indicate

that

cortical activity specific

to

radial motion

develops

between

3

and

5

months,

and

the

contraction

bias

also

develops

during

approximately

the

same age range.

Although

the

adults showed a sirnilar

contraction

bias,

the

cortical

distribution

of

the

bias

oi

the

adults

(the

right-parieta]

area)

was

different

to

that

of

the

in-fants

{the

whole of

the

occipitoparietal

area),

This

implies

that

the

cortical

radial

motion

processing

of

infants

is

different

from

adults.

Such

re-organization

between

infancy

and

adu]thood

of

the

cortical

sys-tems

responding

to

global

motion

(in

this

case

rota-tion)

has

also

been

reported

elsewhere

(Braddick

Wattam-Bell,

Birtles,

Atkinson,

von

Hofsten,

&

Nys-tr6m,

2007).

References

Braddick,

O.,

Wattam-Bell,

J.

Birtles.

D.

Atkinson,

J.,

von

Hofsten,

C,,

&

Nystr6m,

P.

(2007).

High-density

VERPs

show

distinct

mechanisms

for

global

form

and

motion

processing

in

adults

and

infants

stract].

Jbormal

of

Vision,

7(9):

772,

772a.

Shirai,

N.

Birtles,

D.

Wattam-Bell,

J,,

Yamaguchi,

M.

K.,

Kanazawa,

S.

Atkinson,

J.

&

Braddick,

O.

(in

press),

Asymmetrical

cortica]

processing

of radiaL expansionlcontraction

jn

infants

and adults.

QPmental

Science,

Figure 1. {a) Results of the 3L4 (open symbols)

参照

関連したドキュメント

We show that a discrete fixed point theorem of Eilenberg is equivalent to the restriction of the contraction principle to the class of non-Archimedean bounded metric spaces.. We

Keywords: continuous time random walk, Brownian motion, collision time, skew Young tableaux, tandem queue.. AMS 2000 Subject Classification: Primary:

The oscillations of the diffusion coefficient along the edges of a metric graph induce internal singularities in the global system which, together with the high complexity of

Inside this class, we identify a new subclass of Liouvillian integrable systems, under suitable conditions such Liouvillian integrable systems can have at most one limit cycle, and

This paper develops a recursion formula for the conditional moments of the area under the absolute value of Brownian bridge given the local time at 0.. The method of power series

Then it follows immediately from a suitable version of “Hensel’s Lemma” [cf., e.g., the argument of [4], Lemma 2.1] that S may be obtained, as the notation suggests, as the m A

We shall dis- cuss among others: the convergence of Newton’s method; iterated function systems and how certain fractals are fixed points of set-valued contractions; the

Our method of proof can also be used to recover the rational homotopy of L K(2) S 0 as well as the chromatic splitting conjecture at primes p &gt; 3 [16]; we only need to use the