Phonolog ica l Short-term M em ory and its R e la tionsh ip

to L anguage in W illiam s Syndrom e

J u lia G ran t and A nne tte K a rm ilo ff- S m ith

M R C Cognitive D evelopm ent U nit and U niversity C ollege , London, U K

S u san A . G a therco le

U niversity o f Bristo l, U K

S a ra h P a te rson

M R C Cognitive D evelopm ent U nit and U niversity C ollege , London, U K

P a tr ic ia H ow lin and M a rk D av ies

S t. G eorge’s H osp ita l M edica l Schoo l, London , U K

O r lee U dw in

W est Lam beth Com m unity C are Trust, London , U K

W i l liam s sy nd rom e ( W S ) , a ra re neu rodeve lopm en tal diso rd e r of g ene tic o rigin , is

ch a rac te rised by a re la tive advan tage o f language ove r m o re se r ious de fic its in

othe r cognitiv e dom ain s. In th is study the re lation sh ip o f phonological sh ort-te rm

m em ory to W S language , in p a rticu la r vocabula ry , w as exp lo red . U sing G a the rco le

and Baddeley’ s C h i ld ren ’ s T e st of N o nw o rd R ep etition ( C N R e p ) ( G a the rco le &

Baddeley , 1 9 9 6 ) , w e exam ined th e pa tte rn of pe rfo rm ance by W S p a rt ic ipan ts on

that task and com pared it to pe rfo rm ance on m easu re s o f recep tive language ,

v isu ospatia l ab ility , and dig it sp an . In addition , a com pariso n w as m ade of W S

nonw o rd repetition sco re w ith tho se o f tw o g roup s o f indiv idually m atched

no rm ally deve loping 5 -y ea r-o lds , on e on the bas is o f nonve rb a l tes t age and the

othe r on the bas is of ve rba l test ag e . A s expec ted W S r ep e tition sco re s show ed an

effec t of nonw o rd length bu t no t o f phonologica l com plexity . N o nw o rd s tha t w ere

re la tiv ely w o rd like w ere bette r repeated than nonw o rd s that w ere less w o rd like .

R e qu e s ts fo r re p rin ts sho u ld b e sen t to J u lia G ra n t , M R C - C D U , 4 T a v iton S tre e t , L o nd on W C 1 H

0 BT , U K ; em a il : j .g ra n t @ c d u .u c l.a c .u k .

W e sh o u ld like to than k the W ill iam s S y nd ro m e F o un d a tion fo r th e ir he lp in p u tting u s in to uch

w ith f am i lie s . O u r th ank s a re a lso ex ten ded to ou r pa rt ic ip an ts fo r th e ir co -o pe ra t ion an d to the i r

pa re n ts / g ua rd ians w ho se in te re st in the s tu dy w as a sou rc e of g re at enco ura g em en t . W e g ra te fu lly

a ck n ow led g e th e su gg e s tio n o f A l an Badd eley to u se th e C h i ld re n ’ s N o n w o rd R e p e tit io n T e s t w ith a

W S g ro up . W e a re a lso gra te fu l to C o rd e lia H e a d lam - W e lls w ho co l le c ted the adu lt w ord lik en es s

da ta fo r an u n de rg ra du a te pro jec t in th e P sych o log y D e p a rtm ent , U n ive rs ity C o l leg e , L o nd on .

Ó 1 9 9 7 P s ych o log y P ress , a n im pr in t o f E rlb aum ( U K ) T a y lor & F ra nc is L td

C O G N I T I V E N E U R O P S Y C H I A T R Y , 1 9 9 7 , 2 ( 2 ) , 8 1 ± 9 9

C N R ep score s w ere co rre lated w ith test ag es on T R O G , R a v en s , and d ig it sp an bu t

not w ith chrono log ica l age . T e st ag e on th e C N R e p w as a t a sim ila r leve l to th at on

T R O G , R av en s , and d ig it sp an bu t significan tly low er th an on BP V S . T he resu lts

lend support to the v iew tha t phono logy in W S i s a re la tive s treng th . In contra s t ,

d esp ite re lative ly good p roduc tiv e and recep tive vocabula ry , ce r ta in asp ec ts of the

p ro cesse s of w o rd lea rning in W S do no t se em to develop beyond th at o f no rm al 4 -

y ea r-o ld s. T h e good vocabula ry score s of old er ch ild ren and adults w ith W S m ay

be sim p ly due to th eir re la tive ly good phono log ica l sh ort-te rm m em ory .

INTRODUCTION

W illiam s syndrom e ( W S ) is found in abou t 1 in 2 5 , 0 0 0 l ive b irths ( Beuren,

1 9 7 2 ; Beuren, S chu lze , E be rle , H a rm janz , & A p itz , 1 9 6 4 ; C re ery , 1 9 5 3 ;

F ancon i , G ia rde t , S c h lesinger Butler, & Black, 1 9 5 2 ; G re enb erg , 1 9 9 0 ;

L igh tw ood , 1 9 5 2 ; W illiam s , Barratt-Boyes, & L ow e , 1 9 6 1 ) . W S is be lieved to

be a con tiguous gene d iso rder caused by hem izygous subm icroscop ic de letions

on chrom osom e 7 q 1 1 . 2 3 , in clud ing the elastin gene ( E w art et a l. , 1 9 9 3 ) and the

L I M -k inase 1 gene ( F rangiskak is et a l. , 1 9 9 6 ; T assabeh ji et a l. , 1 9 9 6 ) . It can be

d iagnosed on the basis o f a fluorescen t in situ hybrid isa tion ( F I S H ) test fo r the

de le tion of the elastin gene , w hich is found to be absen t in 9 8 % o f ind ividuals

d iagnosed as hav ing W S ( L owery e t a l. , 1 9 9 5 ). H igh leve ls o f w hole b lood

sero ton in have a lso been reported ( A ugust & R e alm uto , 1 9 8 9 ; M a rriage , 1 9 9 4 ) .

W S typ ically presen ts no evidence for foca l lesions in left o r righ t hem ispheres.

R athe r , differing pa tte rns of bra in grow th during em bryo- and ontogenesis resu lt

in d iffe ren t b ra in vo lum e proportions. W S c e reb rum is sm all , but the fron tal

co rtex acqu ires a near norm al vo lum e re la tionsh ip to the posterior cortex

( J e rn igan , Bellugi, S ow ell , D ohe rty , & H e sselink , 1 9 9 3 ; W ang , H e sse link ,

J e rn igan , D oherty , & Bellugi, 1 9 9 2 ) . R e cen t w ork by G a laburda , W ang , Bellugi,

and R o ssen ( 1 9 9 4 ) po in ts to cytoarch itecton ic anom alies in the fo rm of

exaggera ted horizon tal o rgan isa tion of neurones w ith in layers , increased ce ll

p a ck in g d e ns i ty th ro ug h o u t b ra in re g io n s , de c re ase d m ye l in a t ion , a nd

abnorm ally clustered and orien ted neurones , pa rticu la rly in the v isual co rtex .

P h eno typically ind ividuals w ith W S have a facial dysm orphology , w hich has

been charac terised as ``e lfin fac ies ’ ’ , m a lfo rm ations of the connec tive tissues ,

and card iovascu la r defec ts ( J ones & S m ith , 1 9 7 5 ; M c K u sick , 1 9 8 8 ; M o rris ,

D em sey , L eonard , D i lts , & Blackburn , 1 9 8 8 ) .

T he resu lting cogn itive pro file o f the syndrom e is unusua l in tha t a num ber of

stud ies have show n relatively prese rved lingu istic and face-p rocessing capac ities

despite low I Q s ( in the 5 0 s and 6 0 s in the m ain , w ith a range from 4 0 to 9 0 ) , and

se rious deficits on tasks requ iring the in tegra tion of v isuospa tia l in form ation , a s

w ell as num ber , m oto r , p roblem -so lving , and p lann ing tasks ( A rno ld , Y u le , &

M a rtin , 1 9 8 5 ; Bellugi, Bihrle, J ern igan , T rauner , & D ohe rty , 1 9 9 0 ; Bellugi,

M a rks , Bihrle, & S abo , 1 9 8 8 ; K a rm iloff- S m ith , 1 9 9 2 a , b ; K a rm iloff- S m ith ,

K l im a , Bellugi, G rant , & Baron C ohen , 1 9 9 5 ; U dw in & D enn is , 1 9 9 5 ) .

82 GRANT ET AL.

D e sp ite the re la tive streng th of verba l ab ilities in ind ividua ls w ith W S noted

by m any researchers , the resu lts o f recen t stud ies sugges t that w ith in language

itse lf there are peaks and va lleys. By adolescence , W S indiv idua ls typ ical ly have

a relatively w ell-deve loped expressive vocabu lary , bu t w ith a tendency to use

words tha t are precoc ious , unexpected , and som etim es inappropria te ( R o ssen ,

Bihrle, K lim a , Bellugi, & J ones , in p ress ; U dw in & D enn is , 1 9 9 5 ) . L ex ica l

abnorm ality in W S a lso m anifests itself in abnorm ally h igh produc tion of low

frequency words in w ord fluency tasks ( R ossen et a l. , in press) and in the

absence of som e of the norm al constra ints on w ord learn ing ( S tevens &

K a rm ilo f f- S m ith , subm itted ). S om e researchers ha ve sugge sted tha t the

syn tactic com ponent o f language is in tac t ( Bellugi, R o ssen , & K l im a , 1 9 9 5 ;

Brom berg , U l lm an , M a rcus , K e lley , & L ev ine , 1 9 9 4 ; R o ssen e t al., in p ress) ,

and this has led to the c la im tha t W illiam s syndrom e is a prim e exam ple of the

m odularity of language ( P inker , 1 9 9 4 ) . H ow ever , the hypo thesis o f in tact syntax

has been challenged in the ligh t o f resu lts from a num ber of new stud ies. T hese

inc lude im pairm ents in gram m atica l gender assignm ent in F rench and Ita lian -

speak ing ind ividua ls w ith W S ( C ap irc i , S abbadin i , & V o lterra , in press ;

K a rm ilo ff- S m ith e t al., in p ress ; V o lterra , S abbad ini , C ap irc i , P e zz in i , &

O sse lla , 1 9 9 4 ) , im pa irm en ts in le ft b ranch ing re lative c lause processing in

E ng lish -speak ing W S ind iv idua ls ( K a rm iloff- S m ith , V a lian , G rant , & H eske th ,

subm itted) , w ord order and m orphosyn tac tic e rro rs in the language of Ita lian -

speak ing W S ch ild ren ( V o lterra e t a l. , 1 9 9 4 ) , p rob lem s with the sensitivity to

subca tegorisa tion s truc tu res and the access and in teg ra tio n of sem antic

info rm ation into sen tence processing ( K a rm ilo ff- S m ith e t a l., subm itted ) ,

although they show norm al prim ing for isola ted w ords ( T y le r e t a l., in press).

M irror ing the d issoc ia tion usually found in people w ith W S be tween

ling u istic an d v isu ospa t ia l cog n ition , rece n t s tu d ie s h ave po in te d to a

dissocia tion betw een verba l and spa tia l short-term m em ory . F o r exam ple ,

although phonolog ica l short-te rm m em ory ( also know n as verbal o r aud ito ry

short-term m em ory) w as show n to be at the leve l of m en tal age ( U dw in & Y u le ,

1 9 9 0 ) o r h igher than m ental age ( M erv is , M o rris , Bertrand , & R ob inson , in

press) , spatial short-term m em ory turned ou t to be m ore se riously im pa ired

( V ic ari , Brizzolara , C a rle sim o , P ezzin i , & V o lte rra , 1 9 9 6 a ; W ang & Bellugi,

1 9 9 4 ) . V ic ari and co lleagues further report tha t th is d issoc ia tion is not rep lica ted

in long-te rm m em ory , w here bo th m oda lities a re im paired ( V ica ri et a l. , 1 9 9 6 a ).

In a further study of verba l short-term m em ory in W S , V ica ri and co lleagues

adm inistered a w ord span task in w hich w ord leng th , phono logical sim ilarity ,

and frequency were varied ( V icari , C a rlesim o , Brizzolara , & P e zz ini , 1 9 9 6 b ).

T h e W S pa rtic ipan ts show ed norm al sim ilarity and leng th effects in the ir

perform ance on the task , supporting the au thors ’ hypo thesis tha t phonolog ica l

encod ing m echan ism s are re la tive ly un im paired in W S . H ow ever , there w as a

reduced frequency effect in the W S p articipan ts ’ re sponses re la tive to a group of

norm ally deve lop ing ch ild ren. Both groups repea ted high frequency w ords be tte r

VERBAL MEMORY IN WS 83

than low frequency w ords , but the effect w as sm aller in the W S g roup . T his

find ing w as in terp reted by V icari and co lleagues as sugges ting an over-

dependence on phono log ica l encod ing in m em orising w ords and a re lative

absence of a contribution from long-te rm m em ory . T he au thors p ropose tha t the

pa ttern of W S pa rtic ipan ts ’ resp onses in m em ory tasks fits well w ith reports that

W S ind iv idua ls have re latively good phonology and vocabu la ry ( V o lterra et a l. ,

1 9 9 4 ) , bu t show abnorm al pa tterns of perfo rm ance on tasks such as verbal

fluency w hich requ ire e fficien t access to sem antic info rm ation sto red in long-

term m em ory ( R o ssen e t al., in p ress ; V o lterra et al., 1 9 9 4 ) .

T he p resen t study w as designed to investiga te the re la tionsh ip betw een

language and phono logical short-te rm m em ory in W S by m eans of a nonw ord

repe tition task , the C h ild ren ’ s T est of N onw ord R epetition ( C N R e p ) ( G a the rco le

& Baddeley , 1 9 9 6 ) . T he C N R ep w as deve loped by G a the rco le and Baddeley as a

tool w ith w hich to investigate phono log ica l short-term m em ory in ch ildren ,

w ith in a fram ework of the w ork ing m em ory m odel p roposed by Baddeley and

H itch ( 1 9 7 4 ) . In tha t m ode l , phonolog ical short-term m em ory is part of a m em ory

system w hich has th ree m ain com ponents : an atten tiona l system ( the cen tral

execu tive) , and two periphera l , l im ited-capac ity slave system s– the v isuospatial

ske tch pad and the articula tory loop or phono log ical short-term m em ory . T he

fo rm er is concerned w ith construc ting and m anipu lating v isual im agery , w hereas

the la tte r is spec ia lised for the tem porary sto rage of phonolog ica l m ateria l and

com prises a phonolog ica l sto re and a rehearsa l p rocess.

O n e advan tage of testing phonolog ica l short-term m em ory with nonw ord

stim uli as opposed to rea l w ords ( a s in w ord and d ig it span tasks) , is tha t the

resu lts a re no t confounded by d iffe rences in the fam iliarity of the stim uli. T his

can be particu larly true of a typ ica lly deve loping ch ildren fo r w hom rea l w ord

frequency m ay differ from norm al experience. P e rform ance on the C N R e p has

been found to be a be tter p red icto r o f vocabu la ry know ledge than aud itory d ig it

span in norm ally deve lop ing 4 - and 5 -yea r-old ch ild ren ( G a the rco le , W i llis ,

Baddeley , & E m slie , 1 9 9 4 ) , a nd to be c losely related to the reten tion by 1 0 -yea r-

o ld child ren of new ly acqu ired words ( A gu iar , 1 9 9 3 ) . It is also a m ore po werful

p red icto r than d igit span of single w ord read ing ability in 4 - , 5 - , and 8 -yea r-o lds

( G a the rco le , W i llis , & Baddeley , 1 9 9 1 a ; G a the rco le , W i llis , E m s lie , &

Baddeley , 1 9 9 2 ) , and of language com prehension in 4 - and 5 -year-o lds ( W i llis

& G a the rcole , 1 9 9 2 ) . M o reover , scores on an earlie r version of the C N R ep w ere

h igh ly correla ted w ith syn tac tic com plex ity in the spon taneous speech of

preschoo l ch ild ren ( A d am s & G a the rco le , 1 9 9 5 ). C h ild ren w ith spec if ic

language im pairm en t ( S L I ) have been found to be im paired on C N R ep

perfo rm ance , suggesting that S L I invo lves a deficit in phono logical short-term

m em ory ( Bishop, 1 9 9 6 ; G a thercole & Baddeley , 1 9 9 0 ) .

In a study of the assignm ent o f g ram m atica l gender in F rench-speak ing

indiv idua ls w ith W S , i t w as observed that the W S p articipan ts rep roduced

nonw ord stim uli m ore accura tely on the first p resen ta tion than a group of m uch

84 GRANT ET AL.

younger norm ally deve lop ing ch ild ren ( K arm iloff- S m ith , et al. in p ress). T h e

focus of tha t study w as language and all the nonw ords w ere on ly of tw o-sy llable

leng th . H ow ever , the resu lts suggested tha t nonw ord repe tition m ight be a

fru itful techn ique w ith w hich to exp lo re the relationship be tw een language and

phonolog ica l short-term m em ory in peop le w ith W S . T h e nonw ords in the

C N R ep vary in leng th ( from 2 to 5 sy llab les ) , phono logical com plex ity ( num ber

of consonan t c lus ters) , and the degree to w hich the nonw ords resem ble rea l

words. G athe rco le , W illis , E m slie , and Baddeley ( 1 9 9 1 b ) , u sing an earlie r

version of the C N R e p , found tha t in norm ally deve lop ing 4 - to 6 -yea r-o lds ,

pe rform ance on the C N R ep decreased w ith nonw ord leng th . P honolog ica l

com plexity had no sign ifican t effect on perfo rm ance bu t nonw ords tha t w ere

re latively word like w ere easier to repea t than those tha t were less word like.

In the light of the V icari et al. ( 1 9 9 6 b ) results for W S individuals on the word

span task m entioned earlier we can predict that W S p erform ance on the C N R ep

w ill show the norm al decrem ent in perform ance w ith stim ulus length. Because the

phonolog ical system in W S appears relatively unimpaired , phonological complex-

ity in the C N R ep stim uli should not sign ificantly affect performance. T he possible

effect of the wordlikeness variable on W S perform ance was less clear , as the

mechanism s underly ing the effect are no t yet fully understood . O ne of the

hypo theses considered by G athercole ( 1 9 9 5 ) was that the beneficia l effect of

wordlikeness on nonword repetition seen in norm ally developing children involves

the activation of stored lexical representation . If this were the case there would be

som e reason to expect a reduced wordlikeness effect in W S , g iven the evidence of

im pairm ent on tasks that requ ire access to long-term lex ical knowledge. H owever ,

more recen t w ork suggests that the wordlikeness effect is due to sensitivity to

patterns of phonotactic probabilities w ithin the language ( G a the rcole , F rankish ,

P ickering , & P eaker , subm itted). U nder this hypothesis , a wordlikeness effect in

W S nonw ord repetition sim ilar to that found in norm ally deve loping children

would support the v iew that phonology is a relative streng th in W S .

In addition to the ana lysis o f the effec ts o f the aforem entioned variables on

nonw ord repetition in W S ind ividuals , the relationships betw een perfo rm ance on

the C N R e p and scores on tw o tests of receptive language ability , a test o f

nonverba l v isuospa tia l ab ility , and d igit span w ere exam ined. F ina lly , C N R e p

scores for W S ind iv idua ls w ere com pared w ith da ta from norm ally deve lop ing

5 -yea r-o lds co llected by G a therco le and colleagues fo r an earlier study

( G a thercole , 1 9 9 5 ) .

METHOD

Participants

S eventeen ind ividua ls w ith W illiam s syndrom e took part in the study . T he re

were 9 fem ales and 8 m a les w ith an age range of 8 ; 3 to 3 5 ; 0 ( m ean 1 8 ; 7 ) . T h e

partic ipan ts w ere rec ru ited v ia the British W illiam s S yndrom e F oundation by

VERBAL MEMORY IN WS 85

m eans of a le tte r to paren ts / guard ians , inv iting them to fill in a questionnaire and

take part in the study . P a rticipants w ere from a range of socioeconom ic

backgrounds. T h ey had no h istory of m edical p roblem s that m igh t effec t

neuropsycho log ica l function ( such as hearing im pairm en t, se izu res , m en ing itis ,

o r card iac arrest). A l l those of schoo l age w ere in specia l schoo ls o r spec ia l un its

w ith in m ainstream schools.

Materials

T he fo llow ing tests w ere adm inistered :

1 . A sho rt form of either the W echsle r In telligence S ca le for C h ild ren

( W I S C - R o r W I S C - III U K ) ( W e chsle r , 1 9 7 4 , 1 9 9 2 ) o r the W echsle r A du lt

In te lligence S ca le ( W A I S - R U K ) ( W e chsle r , 1 9 8 1 ) , d epend ing on chrono log ical

age , consisting of tw o verba l sub tests ( V o cabu lary and S im ila rities) and two

perfo rm ance subtests ( Block D esign and P ictu re A rrangem ent). T h e W I S C w as

adm in iste red to 1 0 pa rtic ipan ts , and the W A I S to 7 . In addition , the D ig it S p an

from the W I S C w as adm inistered to a ll participan ts , regardless o f chronolog ical

age.

2 . T h e 4 0 nonw ords from the C h ildren ’ s T e st o f N onw ord R epe tition

( C N R e p ) , p resen ted as taped stim uli , reco rded fo llow ing the procedure

described by G a the rcole et al. ( 1 9 9 4 ) .

3 . A language com prehension task , the T est o f R ecep tion of G ram m ar

( T R O G ) ( Bishop, 1 9 8 3 ) .

4 . A te st o f recep tive vocabu lary , the British P ic ture V ocabu lary S ca le

( BP V S ), L ong F o rm ( D unn , D unn , W h etto n , & P in tilie , 1 9 8 2 ) .

5 . A nonverba l v isuospatia l test , R a vens C oloured P rogressive M a trices

( R avens C P M ) ( R a ven , 1 9 8 6 ).

Procedure

S om e of the W S p artic ipan ts w ere seen at the ir school o r tra ining cen tre . M o st o f

them , how ever , w ere tested at the C ogn itive D eve lopm ent U n it in L ondon. T hey

cam e to the U n it , u sually w ith a paren t , fo r a se ries o f v isits in w hich they a lso

took part in o ther studies. T h e testing was spread over tw o to three sessions.

V a rious orders o f adm inistration of tests were used , a lthough partic ipan ts w ere

usually g iven the BP V S first, because vocabu lary is often an area of re lative

streng th . T h is gave us an initia l ``ba llpa rk m easure ’ ’ o f one face t of their

language and gave partic ipan ts a positive sense of achievem ent.

Preparation and Administration of the CNRep

T he nonw ords were recorded by a m onolingual fem ale speaker , w ith in tervals o f

3 seconds be tween each item . T wo tapes w ere prepared , each w ith a d ifferen t

random ised order o f stim uli.

86 GRANT ET AL.

P a rtic ipan ts w ere a ll tes ted by the sam e exper im en ter ( G ran t). T h ey w ere

to ld tha t they were going to hear som e funny m ade-up w ords w hich they shou ld

repeat. A n exam ple w as g iven ( ``durzle . . . so can you say ( pause) `durzle ’ ’ ’ ) .

T h ey w ere to ld tha t they would hear m ore m ade-up w ords through headphones.

T h e tape w as then p layed , inc lud ing the taped instruc tions and prac tice item . N o

partic ipan t had d ifficu lty understand ing the task . If necessa ry , for exam ple

when no response was a ttem pted during the 3 -second gap , the tape w as stopped

to g ive the partic ipan t tim e to respond ( th is w as only necessary fo r one

partic ipan t). R esponses w ere scored im m ediately by the experim en te r as e ithe r

correc t o r incorrec t , w ith allow ance m ade for regional accen t. A l low ance w as

a lso m a de fo r ca ses w h ere an in d iv id ua l w as kn ow n to co n s is ten tly

m ispronounce one sound as ano ther ( e .g . / w / fo r / r / ). T h e responses w ere also

aud iotaped , so tha t uncerta in dec isions could be checked la ter. A t a la ter da te ,

the responses w ere scored aga in from the audio tapes by an independen t judge ,

who had no prio r in form ation about the partic ipan ts other than tha t they had

W S . T h e re w as 9 0 % a g reem ent betw een the tw o score rs. T h is is on ly som ewhat

low er than the 9 7 % a g reem ent betw een tw o scorers ob tained by G athercole e t

al. ( 1 9 9 4 ) on a norm al g roup , so w as considered sufficien tly h igh to w arran t

using fo r analysis the scores obta ined by the on-line m ethod w here lip

m ovem ents w ere also ava ilab le .

W o rd likeness judgem ents o f the taped stim uli w ere ob ta ined from 2 0

un de rg radu a te stud en ts ( w ith equ a l n um be rs h ea ring e ach o f th e tw o

presenta tion orders). T h e studen ts w ere asked to rate each nonw ord on a scale

of 1 ( ``no t very like a w ord a t a ll ’ ’ ) to 5 ( ``ve ry like a w ord ’ ’ ). T h e tape w as

stopped after each nonw ord to allow the participan t to m ake a judgem ent o f

word likeness. M e an ra tings were ca lcu lated fo r each nonw ord .

RESULTS

Verbal and Performance IQ

F irst , the rela tionsh ip be tw een verbal and perform ance scores on the W I S C a nd

W A I S w as exam ined to see w hether th is group of W S indiv idua ls show ed the

re lative advan tage on verbal scores found in several o ther stud ies. S ho rt form

verbal and perform ance I Q sco res w ere calcula ted according to the fo rm ula

given in S attler ( 1 9 8 1 ) . F loor w as set a t 5 1 , to m in im ise artefactua l d ifferences

( com puted floor scores ranged from 4 5 to 5 1 and favoured verbal I Q ) . M e an I Q

and sca led scores are presented in T ab le 1 .

T h e verbal and perform ance sca led scores w ere en tered into a m ixed-design

M A N O V A , w ith subgroup ( W I S C o r W A I S ) a s the betw een-subjects variab le.

S co res on the verba l sub tests were sign ifican tly h igher than scores on the

perform ance subtests [F ( 1 , 1 5 ) = 7 . 0 4 , P = . 0 1 8 ] . T h e effec t o f subgroup w as also

sign ifican t , w ith the group tested on the W A I S a chieving higher scores

[F ( 1 , 1 5 ) = 1 0 . 4 4 , P = . 0 0 6 ] . A s the data in T ab le 1 show , ve rbal scores w ere

VERBAL MEMORY IN WS 87

h igher than perfo rm ance scores in bo th subgroups and the in terac tion betw een

subgroup and test type w as not sign ificant [F ( 1 , 1 5 ) = 0 . 0 1 , P = . 9 4 ] .

W i th respec t to the effect o f subgroup in th is analysis , it w ou ld have been

surp rising not to have found such a d ifference g iven the reports in the lite ra tu re

that , in retest situa tions , ave rage increases of be tw een 4 and 1 7 po in ts a re seen if

in itial testing on the W I S C is fo llow ed by testing on the W A I S w hen participan ts

have reached the appropriate age ( see refe rences in S a ttler , 1 9 8 1 , p . 1 4 9 ; A ve ry ,

S late , & C h avan , 1 9 8 9 ) . M o reover , in a recen t longitudinal study , U dw in ,

D av ies , and H ow lin ( 1 9 9 6 ) found sign ifican t inc reases in verbal , p erfo rm ance ,

and fu ll I Q ( m ean increases of 9 , 8 , a nd 1 1 po ints , respective ly) in ind ividuals

w ith W S tested first on the W I S C a nd la ter on the W A I S . A s the m ean

d iffe rences in the presen t study ( o f 1 4 and 1 1 po in ts fo r the verbal and

perfo rm ance sub tests respective ly) w ere w ith in the range of those found by o ther

resea rchers , it seem s reasonab le to assum e that they w ere due to the usua l effec t

o f the tw o different test instrum ents used to m easure I Q . F o r the rem ain ing

analyses , the refo re , the partic ipan ts w ere trea ted as a single group.

Effect of Nonword Length and PhonologicalComplexity on Repetition

T he m ean num bers of item s correct fo r each sy llable leng th are show n in T ab le

2 . W S pe rfo rm ance w as adverse ly affected by increasing nonw ord leng th from 2

to 4 sy llab les. P e rform ance on nonw ords con tain ing 5 syllab les , how ever , w as

no w orse than on those item s con tain ing 4 sy llables.

T he effect o f nonw ord leng th ( num ber of sy llables) w as exam ined toge ther

w ith the effec t o f phono log ical com plex ity ( p resence or absence of consonant

c luste rs) in an analysis o f variance , w ith item s as the random fac tor. T h e re w as a

sign ifican t e ffect of nonw ord leng th [F ( 3 , 3 2 ) = 1 5 . 3 4 , P < . 0 0 1 ]. H ow ever , the re

w as no effec t o f phono log ica l com plex ity [F ( 1 , 3 2 ) = 3 . 2 3 , P > . 0 5 ] , and no

sign ifican t in teraction be tw een nonw ord leng th and phono log ical com plex ity

TABLE 1Mean Verbal and Performance WISC and WAIS Scores

(and Standard Deviations)

W ISC (n = 1 0 ) W A IS (n = 7 )

V er ba l I Q 6 0 . 9 9 ( 1 6 . 0 7 ) 7 4 . 4 7 ( 4 . 2 9 )

P e rfo rm ance I Q 5 4 . 4 6 ( 7 . 0 9 ) 6 5 . 9 1 ( 8 . 5 9 )

V er ba l S S 2 . 8 5 ( 0 . 7 5 ) 5 . 2 9 ( 0 . 8 1 )

P e rfo rm ance S S 1 . 5 0 ( 2 . 9 3 ) 3 . 8 6 ( 1 . 6 0 )

N o te : S S , sc a led sco re s .

88 GRANT ET AL.

[F ( 3 , 3 2 ) = 0 . 4 3 , P > . 0 5 ] . T h is pa tte rn of resu lts m irrors tha t reported by

G a therco le et al. ( 1 9 9 1 b ) fo r norm al 4 - to 6 -yea r-o lds.

Post-hoc ( N ew m an± K eu ls) tests revea led tha t the W S p artic ipan ts show ed a

sign ifican t decline in repe tition accuracy as the nonw ords increased in leng th

from 2 to 3 , P < . 0 5 and from 3 to 4 sy llables , P < . 0 5 . H ow ever , a s sta ted earlier ,

pe rform ance on 4 syllab le item s w as no be tte r than perfo rm ance on 5 sy llab le

item s. G a the rco le e t a l. ( 1 9 9 4 ) also found tha t the ir sam ple of 4 - to 9 -yea r-o lds

show ed no sign ificant d ifference be tw een scores on 5 sy llab le item s re la tive to

th e 4 sy l la b le st im u l i. T h e y su g g es ted th a t th e p rese n ce o f fa m il ia r

m orpho log ical m ultisy llab ic sequences in the 5 syllab le item s ( e.g . altupa tory ,

con fran tually , d e ferm ica tion ) m ay have offset the decline in repe tition accuracy

seen w ith increases of nonw ord leng th from 2 to 4 syllab les . T r i- and b i-sy llab ic

end ings like -a tory , -ua lly , and -ation m ay becom e chunked after repeated

exposure to recurring phono log ical pa tterns in da ily life , enab ling partic ipan ts to

process them as a un it in our nonw ord task .

A fu rthe r analysis o f variance was carried ou t to see whether the effect o f

syllab le leng th on perfo rm ance rem ained when tw o po ten tia lly confound ing

linguistic fac tors , nam ely , rated w ord likeness and num ber of m orphem es , w ere

en tered in to the ana lyses as covaria tes. T h e re was again a sign ifican t e ffec t o f

num ber of sy llables [F ( 3 , 3 0 ) = 1 3 . 8 9 , P < . 0 0 1 ] , a nonsign ifican t effec t o f

p rese nc e / abse nc e of c on son an t c lus te rs [F ( 1 , 3 0 ) = 1 . 0 5 , P > . 0 5 ] , an d a

nonsignifican t in teraction of the tw o fac tors [F ( 3 , 3 0 ) = 0 . 5 3 , P > . 0 5 ] .

Effect of Rated Wordlikeness on RepetitionPerformance

T w o subse ts o f stim uli w ere derived from the 4 0 nonw ord set fo llow ing the

procedure described by G a the rco le ( 1 9 9 5 ) . Item s in the tw o subse ts w ere

m atched for num ber of sy llab les , num ber of consonan t c luste rs , and num ber of

phonem es. O n e se t con tained 1 2 nonw ords of re latively low -rated word likeness ,

the other 1 2 nonw ords of h igh-ra ted w ord likeness.

T h e m ean num ber correc t for the low -w ord like set w as 7 . 8 8 ( S D 2 . 4 ) and fo r

the h igh-w ord like set 9 .2 9 ( S D 2 . 4 ) . P e rfo rm ance w as sign ificantly be tter on the

high-w ord like set than on the low -w ord like se t [t ( 1 6 ) = 3 . 6 8 , P = . 0 0 2 ] .

TABLE 2Mean Number of Correct CNRep Repetitions (and Standard Deviations) for Each

Syllable Length

2 S y lla b le 3 S yl la b le 4 S yl la b le 5 Sy l la b le

8 . 7 6 ( 1 . 0 9 ) 7 . 5 3 ( 1 . 5 5 ) 5 . 2 9 ( 3 . 2 9 ) 5 . 2 9 ( 3 . 1 8 )

VERBAL MEMORY IN WS 89

T he rela tionsh ip betw een scores on the low- and h igh-w ord like nonw ords

item s and vocabu lary know ledge as m easured by the BP V S w as exam ined by

m eans of corre lationa l ana lyses. BP V S scores and repe tition of the low -w ordlike

item s w ere som ew hat m ore h igh ly correlated , r = . 7 2 , P = . 0 0 2 , than w ere BP V S

scores and repetition of the h igh-w ordlike item s , r = . 6 4 , P = . 0 0 7 ( see F igs 1 and

2 ). P a rtia l co rrela tions w ere then carried ou t con tro lling for language age

( T R O G test age) and repe tition ab ility. T h is g ives an index of the strength of the

un ique rela tionsh ip be tw een each of the repe tition subscores and vocabu lary that

is independent o f language age. W i th T R O G te st age and repe tition score on the

low-w ord like item s partialled ou t , there w as a negative bu t nonsign ificant

re la tionsh ip betw een BP V S score and repetition of the h igh-w ordlike stim uli ,

r = ± . 0 2 9 3 , P = . 9 2 1 . In contrast , the re was a positive and sign ifican t rela tionsh ip

be tw een BP V S score and perfo rm ance on the low -word like stim uli w hen T R O G

FIG. 1. S c a tte rp lo t o f sco re s fo r low -w o rd l ik e i tem s as a fun c tio n o f BP V S ra w sco re s . ( D u e to

l im ited t im e fo r te s ting o ne p a rtic ip an t , a S h o rt F o rm BP V S w as ad m inis te re d . H is ra w score w as

the re fo re n o t in c lu ded in th is an a ly s is .)

90 GRANT ET AL.

test age and repe tition score on the h igh-w ordlike item s w ere partialled out ,

r = . 5 3 , P = . 0 5 . T h e d ifference be tw een these tw o correlations w as exam ined

using the procedure for testing the difference be tween tw o non independen t rs

desc ribed by H ow ell ( H ow ell , 1 9 8 7 ) . T h e re w as a sign ifican t d iffe rence be tween

the tw o corre lations , P < . 0 1 . G a therco le ( 1 9 9 5 ) found a sim ilar pattern in her

da ta from 4 -year-o ld norm ally deve loping ch ildren . In con trast , w hen these sam e

ch ildren had reached 5 years o f age , there w as no re la tionsh ip be tw een repe tition

of e ither type of nonw ord and vocabu lary know ledge.

Repetition Performance in Relation toChronological Age and Scores on TROG, BPVS, andRavens CPM

P e rfo rm ance on C N R e p in term s of raw scores w as not sign ifican tly corre la ted

w ith C A , r = . 4 6 , P > . 0 5 . H ow ever , C N R e p scores w ere significan tly corre la ted

FIG. 2. S c a tte rp lo t o f score s fo r h ig h-w o rd lik e i tem s a s a fu nc t io n of BP V S ra w score s .

VERBAL MEMORY IN WS 91

w ith test age ( T A ) on the o ther four tests ( C N R e p w ith T R O G T A , r = . 6 8 ,

P = . 0 0 3 ; w ith BP V S T A , r = . 7 7 , P < . 0 0 1 ; w ith D igit S pan T A , r = . 5 9 , P = . 0 1 2 ;

w ith R avens T A , r = . 5 0 , P = . 0 3 9 ) .

R aw scores fo r the C N R e p w ere converted to T A s on the basis o f the

norm ative da ta availab le fo r 4 - to 9 -year-o ld ch ildren ( G a the rco le e t al., 1 9 9 4 ) .

T A s fo r C N R e p , T R O G , BP V S , R avens , and D ig it S p an , p resen ted in T ab le 3 ,

revea l an uneven profile w ith vocabu lary com prehension ( BP V S ) outstripp ing

perfo rm ance on the other four tasks.

A w ith in -sub jec ts analysis o f variance on the five tests show ed a sign ificant

e ffec t o f test on test age [F ( 4 , 6 4 ) = 8 . 8 3 , P < . 0 0 1 ] . P e rfo rm ance on C N R e p w as

co m pare d w ith perfo rm ance on th e o ther fo ur task s. C N R e p T A w as

sign ifican tly low er than tha t for BP V S [t ( 1 6 ) = ± 4 .1 3 , P = . 0 0 1 ] . T h ere w ere

no o ther sign ifican t d ifferences. P erfo rm ance on C N R ep was no t sign ifican tly

d iffe rent from that on the m orphosyn tactic language com prehension task

( T R O G ) , the o ther short-te rm m em ory task ( D ig it S pan ) , o r the v isuospatia l task

( R avens M a trices) ( C N R e p w ith T R O G , [t ( 1 6 ) = 0 . 1 0 , P > . 0 5 ] ; C N R e p w ith

R avens [t ( 1 6 ) = 1 . 2 9 , P > . 0 5 ] ; C N R e p w ith D ig it S p an , [t ( 1 6 ) = 0 . 1 4 , P > . 0 5 ] ) .

In sum , a lthough perfo rm ance on the C N R e p w as positive ly and sign ifican tly

corre lated w ith test age on BP V S , T R O G , R a vens , and D ig it S p an , level o f

ab ility in term s of T A on the C N R e p w as significan tly low er than tha t on the

BP V S , whereas leve l o f ability on the C N R ep , T R O G , R avens , and D ig it S pan ,

re spec tive ly , d id no t differ.

Summary of Results

In certa in respec ts , the pattern of results fo r the W S p a rtic ipants on the C N R ep

resem bled that reported fo r norm ally developing ch ild ren . T he re w as a robust

e ffec t o f inc reases in leng th of m ateria l to be stored in phonolog ica l work ing

m em ory betw een 2 to 4 syllab les. N onw ords ra ted by norm al adu lts as rela tive ly

w ord like w ere easier to repea t fo r our W S pa rtic ipan ts than those w hich had

TABLE 3Mean (and Standard Deviations) Test Ages on CNRep,

TROG, BPVS, Digit Span, and Ravens

T est

M ea n (SD ) Te s t A ge

(m o nths)

BP V S 1 0 7 .0 6 ( 3 9 . 5 5 )

D i g i t S p a n 8 1 . 2 9 ( 1 4 . 5 1 )

C N R ep 8 0 . 6 5 ( 2 1 . 6 6 )

R av ens 7 3 . 5 9 ( 1 9 . 9 9 )

T R O G 8 0 . 1 2 ( 2 6 . 6 6 )

92 GRANT ET AL.

been ra ted as less word like . L ike norm al 4 -yea r-o lds , although unlike 5 -yea r-

olds , vocabu lary know ledge w as m ore c lose ly related to repe tition of low -

word like item s than to repe tition of high-w ord like item s.

H ow ever , con tra ry to w hat w ould be expected in a group of norm ally

develop ing ind ividua ls , C N R ep scores were not corre lated w ith chrono log ica l

age . Instead , C N R e p scores w ere corre lated w ith test age as assessed by T R O G ,

R a vens , D ig it S p an , and BP V S . C N R ep test age was sim ilar to tha t on T R O G ,

R a vens , and D ig it S p an , bu t sign ificantly low er than tha t fo r the BP V S .

COMPARISON WITH MATCHED CONTROLS

T h e outcom e of com paring resu lts across five d ifferen t tests necessa rily had to be

treated w ith som e cau tion , a s the norm ative da ta fo r those tests had been obta ined

from diffe ren t sam ples. T o confirm the W S p rof ile w ith respec t to the C N R ep ,

BP V S , and R avens scores ob ta ined in the presen t study , a com parison w as m ade

of W S C N R ep scores w ith data ob tained from norm ally deve lop ing ch ild ren .

G a therco le ( 1 9 9 5 ) h ad adm inistered the C N R ep , R avens C P M , and the BP V S to a

large group of norm al ch ild ren. It w as therefo re possib le to m atch partic ipan ts

from the W S sam ple w ith norm ally develop ing partic ipan ts on the basis of e ithe r

BP V S or R avens scores and to com pare the ir C N R ep scores d irectly.

In the m ain study , W S test age scores w ere higher on the BP V S than on the

C N R ep . W e the refo re expec ted tha t if pa rtic ipan ts w ere m atched on the basis o f

BP V S scores , the norm al 5 -yea r-o lds ’ C N R e p scores w ould be h igher than those

of the W S g roup . In con trast , b ecause W S C N R e p scores were no t d iffe ren t from

the ir R avens scores , in partic ipant pa irs m atched on the ir R avens scores there

shou ld be no d ifference in C N R ep scores.

T h e fo rm ation of m atched groups a lso prov ided the opportun ity of fu rthe r

investigation of the word likeness e ffec t found in the m ain study .

Method

T h e norm ally deve lop ing participan ts w ere a subse t o f a group of 7 0 ch ildren

who were tested at 4 years o f age and a year late r , a t 5 y ears , by G atherco le and

co lleagues on a ba tte ry of tasks which included BP V S ( S hort F o rm ) , R avens

C o loured P rog ressive M a trices , and the C N R ep ( see G a the rcole , 1 9 9 5 fo r fu rthe r

partic ipan t de tails). T he W S p a rtic ipants w ere the 1 7 de sc ribed in the m ain study

earlie r.

A s m ost o f the W S sam ple ’ s R avens and BP V S test ages w ere above 5 years ,

m a tch ing w as carried ou t w ith the norm ally develop ing ch ildren ’ s da ta at 5

yea rs , ra the r than at 4 yea rs. U n su rp rising ly , because of the W S uneven profile ,

it w as no t possib le to m atch any partic ipan ts using bo th R a vens and BP V S

scores. T w o sets o f m atched groups w ere therefo re fo rm ed : a R avens-m atched

group and a BP V S -m atched group .

VERBAL MEMORY IN WS 93

In the R avens-m atched group , w e succeeded in m atch ing 1 5 W S p a rticipan ts

to norm ally deve lop ing 5 -yea r-o lds on the basis o f bo th gender and R avens

( raw ) score to w ith in one po int. M e an R avens score fo r the W S pa rtic ipan ts w as

1 6 . 2 ( S D 4 . 3 ) and for the 5 -yea r-olds , 1 6 . 4 ( S D 4 . 5 ). M ean chrono log ica l age of

the W S ind iv iduals was 1 8 ; 1 0 ( S D 8 ; 4 ) and of the 5 -yea r-o lds 5 ; 3 ( S D 0 ; 2 ) .

In the BP V S -m atched group , we w ere ab le to m atch 7 W S p a rticipants w ith

5 -yea r-old ch ild ren using both gender and BP V S test age to w ith in 3 m on ths as

the m atching variab les ( the raw scores ob ta ined in the two studies w ere not

d irec tly com parab le as d iffe ren t form s of the BP V S had been adm iniste red ).

M e an BP V S test ages w ere 6 ; 1 ( S D 1 ; 1 0 ) and 6 ; 2 ( S D 1 ; 1 0 ) fo r the W S and 5 -

year-o ld participan ts , re spec tive ly. T h e m ean chronolog ica l age of the W S

subse t w as 1 1 ; 1 0 ( S D 2 ; 1 0 ) and fo r the 5 -yea r-o lds it w as 5 ; 3 ( S D 0 ; 3 ) .

Results

In the R avens-m atched group , the m ean C N R e p score fo r the norm al 5 -yea r-olds

w as 2 5 ( S D 5 . 3 2 ) and fo r the W S ind iv iduals 2 6 . 4 7 ( S D 7 . 5 4 ) . T he se scores w ere

no t sign ifican tly different from each other [t ( 1 4 ) = 0 . 6 5 , P > . 0 5 ] . A s expec ted ,

how ever , in the BP V S -m atched group the norm al 5 -year-o lds ’ C N R e p scores

w ere h igher than the W S sco res. T h e m ean C N R ep scores were 2 8 . 7 1 ( S D 3 . 4 )

and 2 0 . 7 ( S D 5 . 1 ) fo r 5 -yea r-olds and W S p a rticipan ts , re spec tive ly . T h e

d iffe rence be tw een the tw o groups ’ sco res w as sta tistica lly significan t bo th by t-

test [t ( 6 ) = 2 . 9 9 , P = . 0 2 ] , and by W ilcoxon , ca rried out as a m ore conservative

test because of the sm all num ber of partic ipan t pa irs , z = 2 . 0 2 , P = . 0 4 .

T he se resu lts confirm ed tha t the disc repancy be tw een the BP V S and C N R ep

scores found in the W S group w as no t typ ica l o f norm ally deve lop ing ch ild ren

w ith the sam e vocabu lary age . In fac t , C N R e p test age tended to be higher than

BP V S test age in the norm al 5 -yea r-o lds , w h ich is the opp osite of the pattern

found in W S .

G iven the sm all num bers in the BP V S -m atched group , the ana lysis o f the

w ord likeness e ffec t w as carried out on the R avens-m atched partic ipan ts ’ sco res

on ly . Both groups of R avens-m atched partic ipan ts scored better on the h igh-

than the low -w ordlike item s. M e an scores fo r W S w ere 9 .2 0 ( S D 2 . 0 8 ) and 7 . 8 0

( S D 2 . 3 7 ) fo r high- and low -wo rdlike item s , re spective ly . F or the 5 -yea r-o lds ,

the h igh- and low -w ord like item s w ere 8 .8 7 ( S D 1 . 8 8 ) and 7 . 6 0 ( S D 1 . 5 9 ) ,

re spec tive ly . T h e scores w ere en tered into a m ixed-design M A N O V A . T h e re

w as a sign ificant e ffect o f w ord likeness [F ( 1 , 2 8 ) = 1 9 . 0 2 , P < . 0 0 1 ] . T h ere w as

no effect o f g roup [F ( 1 , 2 8 ) = 0 . 0 7 , P > . 0 5 ] .

DISCUSSION

A s expected , the W S p a rtic ipan ts ’ sco res on the C N R ep show ed a norm al pattern

in te rm s of the leng th and com plexity variab les. T he sign ificant effec t o f

w ord likeness suggests that in the course of language acqu isition W S ind ividuals

94 GRANT ET AL.

bu ild up norm al represen tations of phono tac tic p robab ilities in the ir na tive

language , and supports the v iew ( K a rm iloff- S m ith e t al., in p ress ; V ica ri e t a l.,

1 9 9 6 b ; V o lterra e t al., 1 9 9 4 ) that phono logy is relatively un im paired in W S . In

con trast , the find ing of a stronger rela tionship be tween BP V S scores and

repe tition scores on the low -w ordlike stim uli , than be tw een BP V S and scores fo r

high-w ord like stim uli sugges ts that , un like norm ally develop ing ch ild ren ,

ind iv idua ls w ith W S co n tinue to re ly heav ily o n the ab ili ty to re ta in

phonolog ica l m aterial in short-te rm m em ory to support w ord learn ing . T h is

suggestion stem s from the fact that the W S d a ta resem ble those prev iously found

for norm ally develop ing 4 -yea r-o lds bu t not 5 -year-o lds ( G a the rco le , 1 9 9 5 ) . In

tha t study , there w as a stronger assoc ia tion of vocabu lary know ledge w ith

repe tition accuracy for low - than fo r h igh-w ord like nonw ords in 4 -yea r-o lds ,

wh ich had d isappeared by the tim e the ch ildren reached 5 yea rs o f age . O n the

basis of this and o ther ev idence , G a the rco le argued tha t the im portance of the

con tribu tion of phono log ical short-term m em ory to w ord lea rning during norm al

developm ent lessens be tween around 4 and 5 years. By 5 years, fac tors such as

the w ay in which lexical item s are in teg ra ted into the existing lex icon m ay exert

m ore of an effect than in earlier stages of w ord lea rn ing. In W S th is shift in the

ba lance of fac tors tha t influence word lea rn ing m ay be a ttenua ted . T h is fits we ll

w ith the find ings of stud ies on W S w h ich suggest an over-dependence on

phonolog ica l encod ing in w ord span tasks a longside im pairm en ts on tasks

requ iring effic ien t access to lex ica l rep resen tations in long-te rm m em ory

( R o ssen e t al., in press ; V ic ari et al., 1 9 9 6 a , b ; V o lte rra e t a l. , 1 9 9 4 ) . T he rela tive

absence of an in fluence of the lex icon itse lf on the acquisition of new w ords

would a lso exp lain w hy the W S p artic ipan ts in the F rench gender study

( K a rm ilo ff- S m ith et al., in p ress) never m is-repea ted nonsense w ords as rea l

words , som eth ing w hich the norm al 5 -year-o lds d id frequently .

T h e find ing that C N R ep scores w ere no t different from R avens , T R O G , o r

D ig it S p an scores confirm s the resu lts o f a num ber of ea rlie r stud ies tha t found

phonolog ica l short-term m em ory in W S to be at m en tal age ( U dw in & Y u le ,

1 9 9 0 ; V ica ri e t a l., 1 9 9 6 a ; W ang & Bellugi, 1 9 9 4 ) , and no t chrono log ical age

level. BP V S scores w ere high rela tive to C N R e p perform ance in the W S g roup ,

a pattern opposite to the one found in the young norm ally deve lop ing contro l

sub jects. R o ssen e t al. ( in p ress) sim ilarly found receptive vocabu lary level in

W S ind iv iduals to be higher than w ould be expected on the basis o f m en tal age.

H ow ever , in the ir study of the W illiam s syndrom e cogn itive pro file , M e rvis ,

M o rris , Bertrand , and R ob inson ( in p ress) , found ra ther d ifferent re la tionsh ips

am ong test scores , w ith aud itory short-term m em ory perfo rm ance superior to

nonverba l spa tia l ab ility and to recep tive language ( bo th syn tax and vocabu la ry).

T h e p rec ise pa ttern of rela tive strengths and w eaknesses in the W S cogn itive

pro file aw aits fu rthe r cla rifica tion .

O u r resu lts con tribu te to grow ing ev idence that , no tw ithstand ing som e claim s

to the con tra ry , language in peop le w ith W S is no t intact. P roblem s w ith certa in

VERBAL MEMORY IN WS 95

aspec ts of m orphosyn tax ( K arm ilo ff- S m ith et al. , in p ress ; V o lte rra et al., 1 9 9 4 ) ,

the integra tion of sem antic info rm ation in sen tence-processing ( T y le r e t a l. , in

p ress) , the non-adherence to certa in princ ip les constrain ing w ord lea rn ing

( S tevens & K a rm iloff- S m ith , subm itted ) , unusua l w ord use ( R o ssen et a l., in

p ress) , and , a s d em on stra ted in th e presen t s tudy , a con tinu ing strong

re la tionsh ip be tw een vocabu lary know ledge and short-term m em ory tha t is

no t seen beyond the age of 4 yea rs in norm al deve lopm ent , a ll sugges t that

peop le w ith W S on ly show a rela tive advantage of language over other dom ains.

W ith in the dom ain of language itself , and even w ith in the subdom ain of lex ical

acqu isition , the re a re bo th rela tive streng ths and w eaknesses.

M a nu sc rip t re c eived 2 4 J u ly 1 9 9 6

R e v ised m an usc rip t re c eived 2 6 N ov em be r 1 9 9 6

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96 GRANT ET AL.

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W in d so r U K : N F E R - N e lso n .

E w a rt , A . K . , M o rr i s , C . A . , A tk in son , D . , J i n , W . , S t er ne s , K . , S p a llo n e , P . , D e a n S tock , A . , L e p pe rt ,

M . , & K e a ting M . T . ( 1 9 9 3 ) . H em izy go s ity a t th e e la s tin lo cu s in a d eve lop m en ta l d iso rd e r ,

W i l liam s syn dro m e . N ature G ene t ic s , 5 , 1 1 ± 1 6 .

F a nco n i , G . , G ia rd e t , P . , S c h le sin ge r Butler, H . , & Black, J . S . ( 1 9 5 2 ) . C h ron isch e H y pe rc a lca em ie

ko m bine rt m it O s teo sk le ro se , H y pe ra zo tam ie M in d e rw uschs u nd k og en i ta l M is sb i ld un gen .

H e lve t ica P aed ia tr ica A cta , 7 , 3 1 4 ± 3 3 4 .

F ra n g isk ak is , J . M . , E w a rt , A . K . , M o rris , C . A . , M er v is , C .B., Bertran d , J . , R o b in son , B.F ., K le in ,

B.P ., E nsin g , G . J . , E v e re tt , L . A . , G re e n , E . D . , P ro sch e l , C . , G u tow sk i, N . J . , N o b le , M . , A tk in son ,

D . L . , O d el be rg , S . J . , & K e a tin g , M . T . ( 1 9 9 6 ) . L I M -k ina se 1 h em izyg os ity im p lic a ted in

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N euro R ep or t , 5 , 7 5 3 ± 7 5 7 .

G at he rc o le , S . E . ( 1 9 9 5 ) . Is no nw o rd re pe t ition a te st o f p ho n olo g ica l m em o ry o r lo ng -te rm

kn ow led ge ? It a l l dep end s on th e n o nw o rd s . M em ory an d C og ni tio n , 23 , 8 3 ± 9 4 .

G at he rc o le , S . E . , & Bad deley , A . D . ( 1 9 9 0 ) . P h o no lo g ica l m em ory d e fic its in lan gu ag e d iso rd e red

ch ild re n : Is th er e a c au sal co nn ec tion . Jou rna l o f M em o ry a n d La n gu ag e , 2 9 , 3 3 6 ± 3 6 0 .

G at he rc o le , S . E . , & Bad deley , A . D . ( 1 9 9 6 ) . The ch ild ren’s te st o f n o nw o rd repe t ition . L o nd on : T h e

P sych o log ical C o r po ra tio n .

G at he rc o le , S . E . , F ra n k ish , C . R . , P ic ke ring , S . J . , & P e a ke r , S . ( s u bm itte d). P h o no tac tic con s tra in ts

in ch ild re n ’ s se ria l re c a ll .

G at he rc o le , S . E . , W i l li s , C . , Badd eley , A . , & E m s lie , H . ( 1 9 9 4 ) . T h e C h ild re n ’ s T e s t o f N on w ord

R e pe ti tio n : A t e st o f p h on olog ica l w ork in g m em o ry . M em ory , 2 , 1 0 3 ± 1 2 7 .

G at he rc o le , S . E . , W i l lis , C . , & Bad d eley , A . D . ( 1 9 9 1 a ). D i ffe ren tiating p ho n olo g ica l m em ory and

aw a re n e ss of rh ym e : R e a d in g and v o cab u la ry d eve lo p m en t in ch ild re n . B riti sh Jou rna l o f

P sy ch o lo gy , 8 2 , 3 8 7 ± 4 0 6 .

G at he rc o le , S . E . , W i ll is , C . , E m sl ie , H . , & Bad deley , A . D . ( 1 9 9 1 b ). T h e in flu en ce s o f nu m be r o f

sy llab le s and w ord likene ss on ch i ld re n ’ s re pe t ition o f n on w o rd s . A p p lied P sycho l in gu is tics , 1 2 ,

3 4 9 ± 3 6 7 .

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P sy ch o lo gy , 2 8 , 8 8 7 ± 8 9 8 .

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M ed ica l G en e tic s , S up p lem en t , 6 , 8 5 ± 8 8 .

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J e r n ig an , T . L . , Be llu g i, U . , S o w e ll , E . , D o h e r ty , S . , & H e s se l in k , J . R . ( 1 9 9 3 ) . C e re b ra l

m o rp ho lo g ica l d is t in ct io ns be tw een W il liam s an d D o w n sy nd ro m es . A rch ive s o f N eu ro log y ,

50 , 1 8 6 ± 1 9 1 .

J o n e s , K . L . , & S m ith , D . W . ( 1 9 7 5 ) . T h e W il liam s e lfin fa c ie s sy n dro m e : A n ew p er sp ec tiv e.

Jo u rn a l o f P ed ia tr ic s , 86 , 7 1 8 ± 7 2 3 .

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VERBAL MEMORY IN WS 97

m o de ls o f d eve lop m en t. Techn ica l R epo r ts in P ara lle l D is tr ib u ted P ro ce ssing an d C o gn itiv e

N eu ro sc ien ce , TR .P D P .C N S.92 .7 , p p . 1 ± 4 7 C a rn eg ie M e llo n U n iv e rsi ty .

K a rm i lo f f - S m i th , A . , G r a n t , J . , Berth o u d , I . , D a v is , M . , H o w l in , P . , & U d w in , O . ( i n

p re ss). L a n gu ag e and W i lliam s sy nd rom e : H o w inta c t is ``in ta c t ’ ’ ? C h ild D evelop m en t.

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Jou rn a l o f C o g nit iv e N euro sc ien ce , 7 , 1 9 6 ± 2 0 8 .

K a rm ilo ff- S m i th , A . , T y le r , L . K . , V o ic e , K . , S im s , K . , U d w in , O . , H o w lin , P . , & D a v ies ,

M . ( s u bm it ted ). L in gu is tic d issoc iat io ns in W ill iam s sy nd ro m e: E v a lu at in g re c ep tiv e sy n tax in

o n-l in e an d o ff-l ine ta sk s.

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W i ll iam s sy nd ro m e : A n im ita tio n s tu d y .

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L ow e ry , M . C . , M o rris , C . A . , E w a rt , A . , Bro th m an , L . J . , Z h u , X . L . , L e on a rd , C . O . , C a re y , J . C . ,

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F I S H , w ith W ill iam s sy nd ro m e: e va lu a tion of 2 3 5 p a tie n ts . A m er ica n Jo urn a l o f H um a n

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M ar ria ge , J . ( 1 9 9 4 ) . C entra l hyp e ra cus is in W ill ia m s syn dro m e . W i l l iam s S y nd ro m e A s so c ia tio n

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P ink e r , S . ( 1 9 9 4 ) . Th e la ng ua g e ins tinc t : Th e new sc ience o f la n gu ag e a nd m in d . H ar m on dsw orth ,

M i dd le sex : P e ng u in .

R a v en , J . C . ( 1 9 8 6 ) . R a vens p ro g re ss iv e m a tr ic e s an d vo cab u la ry sca le s . L o n do n : H . K . L ew is .

R o ssen , M . , Bih rle, A ., K l im a , E . S . , Bellug i, U . , & J o n e s , W . ( in p re ss ). In te ra c tion b e tw een

lan gu ag e an d co gn it io n : e v id en ce from W il liam s sy nd rom e . In J . H . Beitch m an , N . C o h en , M .

K on s tan ta re a s , & R . T a nn o ck ( E d s .) . La ng ua g e lea rn ing a nd b eha v io ur . N ew Y ork : C am bridg e

U n ive rs i ty P ress .

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S teven s , T . , & K a rm i lo ff- S m ith , A . ( s ub m itte d ). W o rd lea rn in g in a spec ial po p u la t ion : d o

in d iv idu a ls w ith W il liam s syn d rom e ob ey lex ica l co ns t ra in ts ?

T as sab eh ji , M . K . , M e tc a lfe , K . , F e rgu sson , W . D . , C a re tt , M . J . A . , D o re , J . F . , D o n na i , D . , R e a d , A . P . ,

P ro sche l , C . , G u to w sk i , N . J . , M a o , X ., & S h e e r , D . ( 1 9 9 6 ) . L I M -k ina se de tec ted in W ill iam s

syn d rom e . N a tu re G en et ic s , 13 , 2 7 2 ± 2 7 3 .

T y ler , L . K . , K a rm i loff- S m ith , A . , V o ic e , K . , S t e ven s , T . , G ra n t , J . , U d w in , O . , D a v ie s , M . , &

H ow l in , P . ( in p re ss ). D o peo p le w ith W S h av e b iza rre sem an tic s ? A p rim ed m on ito rin g s tu dy .

C o rtex .

U d w in , O . , D a v ie s , M . , & H o w lin , P . ( 1 9 9 6 ) . A lo ng itu d in a l s tud y o f cog n itive ab ili tie s an d

edu ca tion al at ta in m ent in W ill iam s sy nd ro m e . D eve lo pm enta l M ed ic in e a n d C h ild N euro lo gy ,

3 8 , 1 0 2 0 ± 1 0 2 9 .

U d w in , O . , & D e nn is , J . ( 1 9 9 5 ) . W i lli am s S y nd ro m e. In G . O ’ Brien & W . Y u le ( E d s .) , C lin ic s in

d ev e lop m enta l m edic in e: N o . 1 38 . B eh a viou ra l p h en o type s ( p p . 2 0 1 ± 2 0 4 ) . L o nd on : M a c k e ith .

98 GRANT ET AL.

U dw in , O . , & Y u le , W . ( 1 9 9 0 ) . E x p re ss ive lang uag e o f ch i ld re n w ith W il liam s syn dro m e. A m erican

Jo u rn a l o f M ed ica l G en e tics , S up p lem ent , 6 , 1 0 8 ± 1 1 4 .

V ic a ri , S . , Brizzolara , D . , C a rle s im o , G . A . , P e z z in i , G . , & V o lte rra , V . ( 1 9 9 6 a) . M em o ry ab i lit ie s in

ch ild re n w i th W il liam s syn d rom e . C o rte x , 3 2 , 5 0 3 ± 5 1 4 .

V ic a ri , S . , C a rl e sim o , G . , Brizzo lara , D . , & P ez z in i , G . ( 1 9 9 6 b ). S h o rt te rm m em ory in ch ild re n

w i th W ill iam s syn drom e : A re d uced con tribu tion o f lex ica l -s em ant ic k no w led ge to w o rd span .

N euro psy cho log ia , 3 4 , 9 1 9 ± 9 2 5 .

V o lte rra , V . , S a bb ad in i , L . , C a p irc i , O . , P e z z in i , G . , & O s se l la , T . ( 1 9 9 4 ) . L in gu is tic a b i lit ie s in

Ita lia n ch ild ren w ith W ill ia m s synd rom e . P re sen ta tion , W i lli am s S y nd ro m e A s so c ia tion S ix th

In tern a tion al P ro fe ss iona l C o n fe re nce. Build in g b rid ge s ac ro ss d isc ip lines : c og n i tio n to g en e , S a n

D i e go , C A .

W a n g , P . P . , & Bellug i, U . ( 1 9 9 4 ) . E v iden ce from tw o gen e tic sy nd ro m es fo r a d isso c ia tio n b etw ee n

ve rb a l an d v isua l- sp at ia l sho rt- te rm m em ory . Jo u rn a l o f C lin ica l an d E xp e rim enta l N euro psy -

ch o lo gy , 1 6 , 3 1 7 ± 3 2 2 .

W a n g , P . P . , H e s se l ink , J . R . , J e rn ig an , T . L . , D o he rty , S . , & Bellug i, U . ( 1 9 9 2 ) . T h e sp eci fic

neu rob ehav iora l p ro file o f W S is a ssoc ia ted w ith n eoce re be lla r hem isp he ric p re ser va tion .

N euro log y , 4 2 , 1 9 9 9 ± 2 0 0 2 .

W e c hs le r , D . ( 1 9 7 4 ) . W e ch s le r in te l lig en ce sca le fo r ch i ld ren – R ev ise d U K . L o n do n : T h e

P sych o log ical C o r po ra tio n .

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P sych o log ical C o r po ra tio n .

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VERBAL MEMORY IN WS 99