Acquisitinn of Covariation Inf o rma t i o n In BlementarySchool Chi ldren
by
ClJillNoseworthy
A thes issubmitted to the School ofGr ad ua t e St ud i e s in partial fulfilment of th e
requiremen tsforth e degre e of Ma ste r of Science
Department ofPsychology MeI\lorial Universityof New foundland
Aug mJt 19 9 5
St. John' s Newf oundland
1+1
NatiOnalUbrary ofC8nada Acquisilionsand BibbographiCServices Branch395~li!lQlonSl_
ClI\a¥4,OriIano K1ACN4
~~b~enationale Direction desacqulsiliooset desservicesbibllOgraphiques
~~~
1(1A ()NoC
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L'AUTEURA ACCORDEUNE LICENCE IRREVOCABLEET NON EXCLUSIVE PERMETIANTA LABffiLIOTHEQUE NATlONALE DU CANADA DE REPRODUIRE,PRETER, DlSTRlBUER OU VENDREDES COPIESDE SA THESEDE QUELQUE MANlEREET SOUSQUELQUEFORMEQUECE
sorr
POUR METTRE DES EXEMPLAIRESDE CETTETHESEA LA DISPOSITION DES PERSONNE lNTERESSEES.
L'AUTEURCONSERVE LA PROPRIETE DU DROIT D'AUTEURQUI PROTEGE SA TIlESE,NtLA THESENt DES EXTRAITS SUBSTANTIELSDE CELLE- C! NE DOlVENTETRElMPRIMESOU AUTREMENT REPRODUlTS SANSSON AUTORISATION.
Abstract
The study wa s designed to determine how children learn covariation information and whether increasing the number of irrelevantdimensionswouldfacil itateimplicitlearning.
Ninety-sixfourth and fifth graders were trained on sets of three stimulivarying in size (l a r ge and small) and shape (c u r ve d and straight). Of thethree stimuli,one representedthe covariation betweenshap eandsize (e.g., large and curved). Hal fof the participants weretr a i ned on sets with one irrelevantdi me ns i on (positionof the stimulus on the computer screen) and half were trained on sets with two irrelevant dimensions (positionand the stimulus pattern; open, filled, or striped). Followingtraining, partici pantswere exposedto a transfertask with novel st.imuli, but the same covariation employed in training. Finally, participants we r egi ve n a verba l awa neneae test req ui ri ngthem to tell theexpe r i me nt e r howt.hny solved the problem. This test resulted inthreeclassifications:
verbal lyaware (explicitle a rn e r s ),pa r t i a l l y aware, and not verbally aware (impl icitlearners).
Al lpartic ipants includ ed inthe anal ys e s reached criterion du ri ng trai ni ng , indicatingJ:hat ch ildrencan
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learncovariationinformation either ey.plid.tly or implicitly. Asthe complexityof the task Lncreeeed, the learning rate forall participants decreased, particularly forthe expLfcit;lee.rners who presumablyrelied on hyp o t he sis testing. On transfer , explicit le a rn e rs performedbetter than implicit Leernera. The imp lici t system was not particularlysmart, perhaps due to a reliance on con t ext.uaccues acquired in as s oc i a t i ve learning . Part ial learners performed likeimplicitlearnerson tr a ns fe r whe n trained on oneirrel e va nt dimension, and li ke explicit learners whentrainedon twoir r ele v a nt di me ns i on s.
Fromthe s e results severalassumptions werema de about cognitive processes. First, both implicitand explicit pathways are activatedin a learning task, with e,:plicit lear n i ng ratefa ll i ng off more steeplyth a n the Lrepl.Lc Lt;
learning rate as a functionof increasingtaskdifficulty. Second, an intersectionoccurswnerebothimplicil~and explicit lear ni ng areoc curr ing at approximately cbe same rate; task difficultyat the point of intersection will va r y between individuals. There fore, an individual who usuallylearnsimplicitlyhas an interceptat a lowlevel of task diffiCUltyand learns difficult
(i i i )
problemsimplicitl Y. An ind ividual ....he usually learns expli citly hasan int.erc e p t. at. a highle velof ta s k difficulty and learns easierpr ob lemsexplicitly. The t.hird assumpt ionwastha t partial learners acquir e informat ionat appro ximately the same rate implicit ly andex p lic it. ly; in ccne x words.ea ch par tial learner isat t.he pointof intersecti on . Whiman individua l is apa rt ia l learner onan easy task, theirimplicitand explicit learningcurves ar e presumed to resemble tho s e of indi vidualswhous ually learn Lmpl LrritLy. When an individualisapartiallearner on a difficultta sk, their implicit and exp li citle a r n i ngcurves are presume d to res emblethoseof individuals whous ua lly learn expli ci tly . The final assumpt i on was that le a r ne rs will showaprefe re n c efor access i ngeither imp licitor expl i citinfo rma tion based on howthey usua lly solve simila r problems .
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Acknowle dge ments
Thefo11o ...·ing stud yis the culmination of many months of hardworkand would no t have been possible without the cooperation and support of severat individuals. Many thanks toth eROT~anCathol icSchoo l Boardand the principals of Hol yFa mil y School and St.Thomas of Villanova for al lowing me to cond1.o:t this stud y in theirschools. As well, apprecia tion is extended to the parents fo r allowingtheir children to participate.
Special thanks to Dr. F.MichaelRabi no witz wh os e patience andgui d a nc e throughoutthe writi ng of this thesis was inuneasurable; I couldnever have completed this without him. Thanksal s o go to Dr. Rita Andersonand Dr. Mark Howe forthei r helpfulsuggestionsduring the las t revisions. To Dr.GaleBu rf o r d andDr. JoanPenne ll, thank-youfor letting thisint e rfe r ewi t h mywo r k, and thanks forli s t e n ing to my frustratio ns.
Fi nal l y , thanks to my closest friends whowe r e a source of incredi blesupport. Todd, for endu r ingendl e s s complainingandkeeping myego intact; Amand a , the only othe r membe rof the Cr isis Interve nt ionClub; and Peter, who unknowingl y pr ov i dedme with inc en t i ve to get thisdon e .
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Abs trac t . Acknowledgements . TableofCo nt e nt s.
TablesandFigure s.
.rn t roduoci.on•
Table of Content s
.ii
...vi ....ix .1
DefL1.ing the conscious-unconsciousdi chot omy 4 Unc o nscio us acquisitionof informa tion... . 5 Implicitlea r ni ng versus explicit learning.... . ...10 sophistication of the implicitsystem. ....12 De f i n i nguncons c iou s processes as "s ma rt".. ..1 4 Implici t processes in thele a r n i ng paradigm. .15 Criticismsand impo s i ng criteria. .. .. ... ...17 Ins u ri ng conformityto in f o rma t i onand
sensit ivitycr iteria .. .27
Adevelopmental perspective of unconsciouslearning..28 Transfertask as a methodfor inc r e a s i ng sensitivity.35 Advantagesgained by using childparticipants 37 Overview.. . .
Predictions .
. .38 ..4 0
Metho d .
part icipants.
. ..•••.••.•• • •• •• ••••• •••• . .•• ••42 ..42 (vi )
Design. .. 42
Stimuli, .. ..43
Training. .. . .43
Transfer... ..45
rxocedure , ,.... . 46
Result s.. . ... ..48
preliminaryanalysis,. . ...49
Ve r ba l awareness..". .. , .... 50 Number of participantscategorizedat each
level of awareness as a functionof
number of irrelevant training dimensions... .... .52
unweightedmeans analysis ...52
Errorsto criterion. ... 52
Cr i t e rion latency ... . ...54
Transfer latency.. .54
NUmber of correct responses on transfer 54
Discussion '.' ,.,. .57
Methodolog icalissues , , , ,.. 59
Acquisition of covariation information. , 60 Implicit versus explicit learning. ,. . . .... . . . .. ..61
"Smart" mental processes.,...,.,... .,..67 Partial learners.... . ... ....70 Summary and conclusions.,.
(v i i )
. , ,. 7 4
References .
AppendixA- VerbalAwarenessTes t.
(v i ii)
• ..• •79
. 93
List of Tablesand Fi gu r e s
PAGE Table1. Numberof Pa rti c i pants Per Cel l as a Function
ofIrrelevan t Training Dimensions,Gender, and Awa r en e s s Score.... . ... ... .84 Table2. Me a nEr r ors to Crite r ion(St a ndar dErrorof the
Me an) as a Functionof Irre l ev a n t Training Di me ns i o n s andAwareness Scor e . . .... . 85 Table 3. Number ofCo rre c tRe s pon s esallTr an s fe r (Standard
Error oftheMe a n)asa Function of Awareness Scare and Numberof Irrel e van t Traini ng
Dimensions. .8 6
Ta ble 4. Numbe r of Correct Respo nseson Tra ns f er(Standa rd Erro r of the Mean) as a Funct i onof Grade and
Test.... .... . ... .... .. . .87
Figure1. Example Stimulus Sets UsedinTr ai ning .. .. . ...ss Figure2. Exa mpl e Sti mulusSe t Used inTr a ns f e r .. .. .89 Figure3. Ta s kDH fi cul t yInter cept for usuallyImplicit,
Averag e , and Usua llyExplicit Learners 90 Figu re 4. populat ionof Pa r ti cipants WhoLearnat the
Same Rate Int r ins ically andExtrinsicall y as aFun ction ofTaskDiffi c Ul t y 91 Figure5. Liklihood That Part ialLearners WillAccess
Exp l i c it Inf o rma t ion on Tr a n s f er Taskas a Functionof the ValueofTas kDiff i cu l t y at the Int ercep t Point.... .... . ....92
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Introduction
Are c e n t debatein the cognitive literaturehas focussed arou ndhow "smart "or "d umb" the unconscious is. One of thema i n questionstha t has beenre s e a r ch ed involves the level (o r levels) of analysisat whichthe coqnd t.Lve unconscious fun c t i o ns as it processes informationthat can laterinfluence thoughts,pe rceptions, and behaviours. Researchand reviews to dat e uncovermixedevidence for simpleversussophist icatedunconsciousprocesses. Consequently, a renewed int e re st in, and greater scrutiny of, the cog n iti ve unconsciousha s ensued .
The cogni tiveli terature is rich withevide nce for unco nsciousacquisitionof information, particularlywithin primingstudiesand lear ni ngparadigms. However, other tasks haveyielded in f o rma t i o n thatis inc o n s i s t e n t regarding the sophisti cationof unconsc iousprocesses (s e e Greenwal d , 1992; Shank s&St.John, 199 4 fQr reviews). primingstudiesdemonstratefac il itationof the per ception of previous lyseen single wo r ds and figures, even when those words andfiguresaredeg rade d to thepoi nt ofno t being consc ious l ydetectab le (Tulvi ng&Schacter, 1991 ; Lo f t us &
Klinge r , 1992). Howe v er, fa cilit a t i o n has not been obtained
with mare complex sequences of words. Thus, priming seems to occur with simple but not comp Lex stimuli.
Similarly, subliminal activation research has yielded inconsistent results which consequently challenge the soph Lsu LcatLcn of. unconscious processes. In subliminal activation studies target stimuli (visual or auditory) are below the threshold for conscious detection. Kunst-Wilson and zajonc (1980) reported that participantsexposed to shapes at intervals too brief to allow for later recognition, gave more favourableratings to those stimuli to which they had been previously exposed. Mandler, Nakamuri, and Van Zandt (19B7) found that pr:7.orexposure in the absence of recognitionfacilitatesany xefevaut;
judgement about the stimulus. Cl e a rly , informacionchat can facilitate later performancehas been processed at;an unconsciouslevel.
Greenwald (1992) argued that despite the evidence for unconscious processing in priming studies, the processes cnemeerveearenut particularlysophisticated. Therefore, such evidencele nd s nocredence to the unconscious as a complexentity. Similarly, with re sp e c t tothe subliminal ac t i va tio n research, Gr eenwa ld pr opos e s that the memory
tr a c e sforsha pe s or words presentedduri ng the expos ure phases arequit e simplis tic and shou ldnotbeusedas ev tda nce,fo r a highlysophistic a tedunconscious . Greenwal d
(1992) does notattempt to discount evid enc e for unconscious proc e s ses. However , he doescau tLonre ad e r s that the level s of analy sis uponwhic h the unc onsc i ou s is ope rat i ngin thes e stud i e s aresofunda ment.aLthatarguments fora comp l e x unc onsciousare premature .
Despitethesc e pt i c i sm, much res e archexists in support of the activationofthe unconscious ,parti cula rlywithin learningparadigms. Suc h unconscious ac quis i t i on of in formati on , or so- called "i mpl ic itlearning", has been demonst r ate d in the cognitiveli tera tu reandwillbethe focu sof thisstudy (s e e Re ber, 1989; Le wi c ki , Hill &
cayee vsx a, 1992fo r reviews ).
Inthefollowi ng sec tio ns, is s uesrela t ed tothe impli citacqui si t ion of in f o rma tion willbeaddressed. Distinction s will bemade between the con s c i ousand unconsciou slearningpathways, whet her the unconscious pa thway is capable of acquiringinformation, howthe implicit systemmay be more effic ient tha n the explicit system, the relat i ve sop his t i c a t i on of the implicit system,
and whe t her or not thepr oc e s s e s engaged inby the implic it system may be re ga rd ed as"s mar t " . Criticismsof implicit learn i ng researchalso willbe discussed. Specific to the present study, unconscious learning wi ll be add r e s s e d from a developmentalperspectiveand rea s on s will be presented regardingwhy childrenmay bebe t t erpart i cipa nt s than adults in implicitlearning studies.
Defi n ing The Conscious- llnCQJ1sci0uB Dichotomy
Al t ho ug h at the most basicle v e l "un c o ns c i ou s"merely means "unawa r e of". Greenwald (1992) pos e s two senses of the conscious -unconsciousdichotomy. The first sense of
"unc o ns c i ou s" is that which is "outsideof attent ion ". From this point of view, the conscious endof the dichotomyis viewedas a select iveaspectof attention. Therefore, is unconsci ousor unawareof a stimul us when it falls outside the focus of selective attention but still impinges on receptors. An illustration of thisse n s e of
"unconscious"wouldbe thedi c ho ticlist e n i ngtas k , In this select!ve attention task, two differen t messagesare del iveredtothe two ears, but only one me s s ag e , that which is delivere d to the primarychannel, usuallyis attend ed to . Someevidence ex i st s fo r the lowle v el ana lysisof phy s ica l
featuresand intermediatele v e l analys isor: wordmeaning frominformatio ndeliveredin the secon darychannel, providing suppo rt for the uncon s c ious proce s s ingof una t t end ed stimul i (s ee Gre e nwald,1992, for re v i ew).
The sec o nd sens eof -un c o nectoussde s cribedby Greenwald (199 2) is ·l a c k0::'"failu r e of rnerospecetcns . Here, if consciou sne s s ispz'naurned tobe anind ivi du a l's abilityto valid.ly report experience, then unconscious ness isde scr i b e d as an individua l'sinability to verba llyreport the stimuli to which the y haveattended. Such dissociation between performance and awarenesshasbeen demonstrated in mos t impl icitlea rning research (Rebe r, 1967; Reber, 19 7 6;
Reber &Lewis, 197 7;Lewicki,19 86; Lewi c k i, Cz yzews ka, &
Hof fma n, 1987;Lewicki,Hill, (. Biz o t, 198 8 ). I tis thi s sortof"ve r ba l l y unr eportable·acqu i s i t i on of in fo rma tion thatis thefocusof the present study.
Uncpnscious!tcmlisitionQf Inf Qmation
The next po int of contention is whe the r it ispos s i ble for humans toacquireinformation unconsciously; thatis, wi t hou t th einfo rma tio nbe i ng verba llyreporta b l e. Despite the cur r entdebatessur rou nd i ng the sophisticationof implicitprocesses, the answer wouldappearto be"ye a'".
Such "implicit learning", accordi ngto Reber (1967), occurs withoutconcurrent awareness of what is beinglearne dand can be viewedas dist inctfrom"explicit learning". But what exactlyis implicit le arn i ng ? Se ger(1994)offers threecriteria tha t characteri z ethe nature of implicit learning. The first crite r ionstates that theknowl e dge thatis acquiredas a funct ionof implicit.learning isno t available tocon s ci ou s ne s s. Thiswoul dappearto be the case byvirtue of the factthat individualsparticipat ingin implicit learningstudiesare rare l y capableof providing a verbal account of whatthey havelearned (Lewicki, 1986;
Lewicki ee al., 1987; Lewicki et aL;, 1988 ;Re b e r, 1967;
Re be r &Lewis, 1977).
The second criterionstates that the information acqui redduring impl icitlearning is more complexand sophisticated th a n thele a r n i ng ofsi mpl e associationsor freque ncies (Seger, 1994) .Seger (1994) contendstha t implicitlearning re f l e c t.s the acquisition of information th a t is rather abs tractand presumab lytoosophis t i c a ted to be ha ndl e d efficientlyby the conscious. Both of these criterionecho thedes criptionsalready pu tfo rthby Rebe r (1989 ) and suppo r ted byLewi ck i et al. (1992 ). However ,the
existing literature fails to specify the processes that may be involvedin implicitle a r n i ng . Despite the conjectures of Seger (1 994) , participantsmay indeedbe le a r ni ng simple associations or automaticallytallyingfrequency cou nts. For example, in the rule-basedimplicitle arn i n g paradigm, such as the artificial grammarstudies of Reber (19 67;
1976), some bi grams or larger stimulus atring segments are generated that have a higher fr e qu e nc y countth a n others.
The participants in thesestudies may become sensitive to the frequency of certain segments. Similarly. in the pattern learning paradigm employed by Lewicki and colleauges (1 986 ;198 7,' 1988) the participants mayac qu i r e associations between segments of the stimulus patternsthat precede the key trial andthe key trial itself.
The third criterion pu t forth by Seger (1994) is that implicitlearning is an "incidentalconsequenceof the type and amount of processingperformedon the stimul i" (p.164).
anddoes not involve the processes used during conscious hypothesistesting . Seger (1994) proposesth a t suchan interpretat ioncan defendagainstthos e argumentssuggesting thatthe participantshavegained fragmenta ryknowledgeof the rulesthat governthe experimen tal task (Dulany.
Carlson, &Dewey, 1984; Perruchet, Gallego &Savy, 1990;
Shanks&St. Jo hn , 1.994). Because the participants have not acquired their information through hypothesis testing (conscious pathways), one might conclude that an independent and unconsciouspathway was used.
Evidence for unconscious or implicitlearningcan be bestill us t r a t e d with the work of Reber (1967 , 1976) and Reber and Lewis (1977). In one of his earliest studies, Reber (1 967) showed participants exemplary strings of a l:ule-governed artificial grammar. The participants, however, were not informed that the grammarwas founded on a set of rules . lnstead, they were instructed to use rote rehearsal tactics to memorizethe strings they were shown. Results demonstratedthat those participantsrequired to memorize the rule-governedstrings improved across trials, Control participants,who were given strings of random letters with no underlyingset of rules. showed no marked improvement in memorizing the letter strings. Despite the neutrality of the instructions, the experimental participants appeared tobe come sensitive to the rules that governed the artificial grammar. Reber (1967 ) concluded tha t participantsle a r nto use thestructural relationships
that exist in aco mpl e x stimul us environme nt , andus e tha t information todi r e c t theirchoices. This findinghas been supported byothersprOVidi ng evidencethatat some level theunc on s ciou s is capab.Lu of acquiringnew information
(Morgan&Newpo r t , 1981; Dulanyet al . , 1984).
Si mil a rly , Broadbent and colleagueshavede mo ns t r a t e d that participant s ca n implicitly le a r nthe complex r.n ee governinganeconomic /productionsimulation. In a seriesof studies, participants were givena hypothetical
manufactur ingdilemma Whereby they wererequired to manipulatevariableslike wagesand worker outputinorder to yielda satisfactory pr odu cti onst a nda r d. Unknown to the part icipants, the simulationopera tedon ... set of sophisticatedrules tha t rela tedvariab lesto eachother.
Consequent ly, these ruleswo u l d ha v e to be kno wninor der to achievethere q u i r e d productionstandard. Re s ult s showed that thepar tic i p a nt s acquiredthecompl e x rules. The acqu isi tionappeared to beimplic i t as theyha dno conscious knowledge of those rules (Br oadbe n t &Aston , 1978; Be rry&
Broadbent , 1984 ; Broadbent, Fi tzgerald, &Broad bent , 1986).
Implicit learningVersu6 ExplicitI,earnin g
The studiesmentioned above involved the with'noldingof specificins t ructions and information to the participants . The instructionswere sufficientlyvague toinsurethe participantswouldno t be motivatedtoloo k for existing patternsand regularities. Given the evidencefo!
unconsciou s or implicit le a r n ing under these co ndit ions, ReberandMillward (196 8) setout to de t e rmi ne wha t effec t explicitinstructions, and consequently, explicit learning, would ha v e on the performance of individuals. More specifically, wouldparticipantsgiven explicit
instructions, as comparedto thosegiven vague ins t ruc t i o ns , be at an advantage? Or, put differe ntly,would participants learning explicitly out performthosele a r ning implicitly?
Reber and Millward (1 96 8)used a probability learning paradigm. participantswere required to indicatewhichof a number of lightswoulddominateinbrig h t ne s s overa series of trials. One group was givenexplicitinstructionswith re s p e c t to thefr e qu e n c y and probabi lityrules that governed the task; the other group was not givenanyspecific in formation. Contra ryto expectations , the groupwhich receivedspecificinst ruc tioos re ga r d i ng the rul e s did not
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perform anybettertha n thegr o up thatre c eived onl yva gue instructions. More impor tant ly, thepa r tic i pa n t s re ce i vi ng spe c i fi c instruc tions reportedthatalthoughthe
instructionsthey weregivenwerepreciseand reli a b l e, they werenotau f fIc i.ent, Actua l experiencewiththe taskwa s whatpa rt i cipa nt s reported re l ying onmost heavily (Reber&
Millward, 1968).
I two uld appearthat in tasks that employ fr e qu enc y and probabilityrules,consciousp roceaees (e x pl i cit) are not as efficient as unconscious processes (implici t) at Lea'rn.lnq information.Actua l experience with the task may be more bene ficialto the participantsthan exposure to complex and potentiallyconfusingrule s . This propositionwas eludedto by Reber (1976 ) . In his stud y, two groups were requi r ed to memorize ex empl a r sfr oman ar tificial gr a mmar . However, one group was explicitly ins t ru cte dto look for the structu re that guidedthe grammar whereasthe othergr oupwa s given instructionstha t werevague. During the test phase, partici p antswereaskedto assess thegrammatical correctness (withinthe constraintsof the artificial grammar) of novel stri ngs. participan tswho wer egive n ex p lic itinstructi ons perform e dmore poo r l y thanthos e gi ven
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vague instruct ions.The s epa r t i cipa nt s tooklonge r to learn the exempla r s, pe rf o rme d morepo o rly on the grammatical correctnesstask, and induced ru l e s thatwerenot close to those be i ng employed in the artificialgrammar.
Sophistication of theImp] ici t Te a rn j ngSystem In the learning experimentsdescribedso fa r , participantsdemonstra ted their knowledge th r oug h improved pe rfo rma nc e, but theywere unabletoverbal i z e those rul es that were presumablyaccount ingfor their performance. What is the natu reof the learning ta s k that makes unconscdoua pr oc e s s i ng a more li kely optionthan consciousprocessing?
Seger (1994) notes that allof thestimu lus struc t ures employed for impl ic it le arni ng studies are complex, in fact, so complex that participantscannot verbalize the patterns re s po n s i bl efor perf o rmance change. Itis possible that impli cit learningprocessesfu n ctionide a lly onlywiththose pa tt erns that are highl y complex. Thisis not an unreasonableassumption giventhat simple patte r nswould be more likely to become known ex p licit lythroughnot icingthe pa t te r n iucident a l lyor eng a ginginconscious hypothesis testi ng (se ge r, 1994). Whether the process isinciden t a l or afunc t ionof conscious hyp o the sistes t ing , Seger (1994)
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believes th a t simplepatterns and rulesar e obviousenough to bepi c k e d upby the conscio us.
In addition, the cognitiveunconsciousappears to be adept at processingcompl exinformationthan the conscious. As was demonstra tedby Reber and Mi l l ward (1968), whoinvestigatedthe effectsof explic i t versus vague instructions, implicit pr oce s s i nghe l d an advantage over explicit pro c e s sing . Th e opinion thatimpl icit processes are superior to ex p l icit processes when stimuli are composed of complex conti ngenciesis also heldby Lewickiand colleagues. Lewickiet al. (1992) be lie v e that the re s e arc h to date indicates that unconscious acquis it ion processesar e not only fa s t er . but structurally more sophisticated than consciousprocesses. In add i tion . they contendthat unconscious processes allowfor..the development of proc edura l knowledgethat is unknownto conscious awareness no t merelybecausei t has be e n encoded ... thr ou gh channels tha t are independe ntfrom
consciousness. Thiskn owl ed g e is fundamentally inaccessible to the consciousbecauseit involvesa moreadvanced and structura lly mo r e complexorganiza tionthan couldbe handl e d by consciouslycontrol ledthinking "{Le wi cki et al., 1992;
13
p. 796). This is precisely the position that is defended by Seger f1994).
Despite Lewicki (1992) and Seger's (1994) suppor t for the sophisticacion of implicit pr o c e s s i n g , neither offer a mechanismexplaining ho w or when implicit learning is lik e l y to occur. Specificat ionof sucha mechanismmight foste r an unde rsta ndingof implicit le a rn i n g . As an initial attempt, it is proposed that bothimp licit and explicit le arn i ng occur in parallel,with the observed process beingt:hat whichacqui res the necessary informationmost quickly.
Whet herthat process is explicit or implicitwould most likely depend onthe complex ity le ve l of the task.
pefjnjngUnconsciousproc e s s e 5as "S~
Fromthe ev i denc e pr e s e n t ed above, it appears that the unconsciousis capab leof proe..es:'3 ~ngin formation, an dthat huma nsare capableofusing the information whichhasbeen acq uired implicitly. Inotherwords, theunconscious appears to be "s mart " . It is exactly thisconclusionthat has sparked therecent debatesbetween those who support a smartunconsc iousand those whodonot . Itis necessary to note here wha t defines a • smart " pr oces s. According to Lof tusan dKlinger (1 992), smart processe s can be
14
categorizedin diff erentway s. One factorees cr me cby Loft u s andKl inger (1992) is ce r t a i nl y not ne w. Advocated by Greenwa l d (19921, a -smart-me n t a l pr ocess can be definedasone that is complex. Ifwe were to pola rize, the analysis of bas i c stimulili k e line sand angleswoul d fall on thesimpli stic end of th e continuum. and the more intr i cat.e analys is or:mult i-s t ringwordsandthei r rel a tio ns wou l d fall onthe complex en d (Gre en wald, 1992 ) .Thus the
?r o ce s s i n gof pat.te r n sint o abstrac t and sophistica t ed in fo rmationwouldco n s titu te a sma rt pr oce ss (Loftus &.
Klinger. 1992 ).
Ano t her fact or , de s cribed byLoftusandKlinger (1992), that may deem a process"smart", is theabilitytodeal with nove l situa t i o n s. Thus , a proce s s tha t can func t ionally ada p t to anat yp i c a l situ a tionwou ldbeconside r ed "s marte r - thanone thatcannot makecr eat iv e useof re s our ce s to sol ve a noveldilemma.
Impli c i t Proces ses inthe Implicitlearni ng parad igm In theimplici t learn i ng pa r ad i gm, stimuliare above th e thr e s h ol d fordetection (s upra limi nal). That is, part i cip a nts areawa reof the pre se nce of t.he stimuli. However, they are unaware ofthe relat ionsh ip{s )betwee n
15
those stimuliand the required responses. A clear example of supraliminalinf o rma t ion and unconsciouslearningis the wo r k of Reber (1967; 1989). In his ar t if i cial grammar and probabili tyle a r ni ng paradigms,thest i muli are nevermasked or hidden from theparticipants . However. the relationships between the stimuli inthese paradigms are inconspicuous , and itf.a these relationshipsthat the part i cipant s must learn, pos sib l y at an unconscious leve l, in order tosol v e subsequen t tasks .
Lewickiand colleaguea (1987; 1988) have also us e d the prObabilitylearningparadigm toinvestigateimplic it processes. In the patternlear n i ng ex p e r i me n ts, participantsare seated in frontof a computer screenwhich is dividedintofou r quadrant'. At set intervals, the target stimuluscan appearinanyone of the fourquadrants.
Theirjob isto indicate, as quickly as possible following targe t exposure,in whichof the four quadrants the targets appeared . The target loc a t i on is not random butgoverned by a set of complexrules .The position of the targetinBorne of theprecedingtr i als determineswhere the target ehouLd appear in the final key trial of a sequence .
16
Over trials the participants show improvement as their response rates to target positionbecome quicker and their success rates higher; clearly they are becomingsensi tiveto therul e s upon which the sequences are governed (Le wi cki et al.,1987;Lewicki, Hill, &Bizot,1988). Moreover, once the trials are completedand the participantsare required toindicate to theex pe riment e r what ruleswere us e d, they are unable tove rb a l i z e the actual setof rulesup o n which the patternwas based, This is to say that there is a dis s ociat i onbetweentheactualperformance and the awareness of theru l e s tha t guided performanc e .
Alternatively, asGreenwald (19 92) wouldput it, the re is a lack orfa ilu r e of introspection; this can be taken as evi de nc e for unconsc ious learning (Le wi c ki et al., 1987; 1988).
Criticismsand ImposingCriteria
The data and conclusions reachedby both Reberand Lewickiand colleagues, although impressi ve, are controversial. Someresear~hersclaimtha t the results obtainedby Reber (1967; 1977 )and Lewicki et al. (1987;
1988) are the dueto participants having acquireda partial conscious knowledgeof the patterns that developduring the
17
exper imental procedure s. In somestud i e s. experimenters havefound thatpar t i cipa ntscoul drep ort fr agme ntsof the complexrules thatgovernedthe expe rimen tal patterns (Dul any et al ., 1984 ; Perru che t et al. ,199 0; Br ook s&
Vokey , 198 9). Itcou ldbe thecase that the rulesgoverning those particu lartasks were too obvious or simplistic and, thus, easilydi s c e r ne d bythe conscious.
Shanks and St.Jo hn (1994 ) haverecen t l ypr op osed two criteriatheyar g ue must be met in order to concludethat unconscious le a r n ing has taken pl ace. Fi r st , the Inf o rma t i o n Criterionrequi restheexperimen tertoes t a blis h that theinfo rma t i o n sought in the awarenesstest (t hat is, thetest that will assesswhe t h e ror no t the subjec t is aware of the rules that under l iethe task the y ha v e compl eted) is indeedthe informationthatisre s p on s i b l e for the performance change inthe partic ipa nts. Second,the sens i t ivi tyCr i t e ri o nrequi r e s that the awareness test be sensitive,or able to pickupon al l of therel e v an t conscious in forma ti onpo s se s s e dbythe sUb jec t. It is possi b le that a performancetest is quitesensi tiveto conscious informatio n , where a s an awarenes stes t is not sens i t iveto that same informat i on (Shanks &St. John,
18
1994). Theendresult then, isappare nt unconscious le arni ng that shouldbe at tributedto conscious process e s.
From the pe rspeccIve of Shanks and St. Jo hn (1994), the research of Lewicki et ar. (1987) doesnot satisfy the above mentionedcrite ria. Inthe i rpatternlearni ng study, Lewicki etal. 11 9 87 ) showedpartic i pantsnonrandom sequencesat targetson acomputer screendivided into tour quad ran ts. The parti cipantswere re qu ired topre ssthe butto n thatcorrespond e dwi ththequa d r ant in whichthe targ e t appe a r ed as soon astheywe r e awareat the target loca t ion.parti c i pant s were expo s e d to twelvehour-l on g sessions,di v i d e d into fourse gment s by short breaks. Each segment consistedof 96bl oc k s,wit h eachbl o c k composed of sixsi mpl e trials followedbyone complexmatrix sc anning trial. On asimple trial, the target appeared.cle a r lyin one of the four quadrants. On the complex trial, thetarget was sbovn againsta back-d ropof visual noise It he ta rget wasembe ddedin a36 di g i t dist ra c t er display ) making it mo re diffi c ul t for the sub jecttode t e c t. Unknownto the part icip a nts , thepositionof the targetonth i s «cce ptex'' trialwasa funct i on of the positi onof th e ta r ge t s onfour of the sixpre c:f!di ng "simple" trials (I, 3,4, and 6). The
19
positionsof thetarg eton theremaini ng two"s i mp l e " trial s (2 and 5) wer e ran dom an d irrelevant in dete rm ini ng the positionof th e ta r ge t on the complex tr i a l .
Th i s relation wa s rathe rcomplicated. No n e t hel e s s , the participantsappeare d to become seneitiveto thenonrandom natu reof the target pr e s ent a t i ons asevi d e n c ed bydecr e a sed response la t e n c i e s over tria ls. In ad di tio n, whe n asse ss e d on the awareness test, thepar t i c ipa n t swe r e una b l e to ve rbal i z.e th e comp l e x relatio n ship that determin e d the pla c e me nt: of the target onkey (compl e x) tri al s - th erewas complete dissoc i a t ionbet wee n perf o rm an c eandaware ness.
Shan k san dSt. John (1994) , howeve r, ar gue that thes e conclus ion s are inco rre ct. The pr o b l e m lies inwhat Shanks an d St.Jo hn (199 4) referto as "micro-rules ", that ena b led th e participants toacquire a fragmentaryknowledgeof the rulesgover ni n g thesequences. Inrevie wi ng the four key simpl etr i a ls, Shank s and St.John (19911) foundthat althou gh thoroughkno wledgeof the seque nc e gua rant eed ce rta i n t y about th e targ etpl a c e me nt in the seventhtria l, the sixth tr i a l al onewas in fo rm a t i v e en o ugh to increaseth e probab i li ty ofgue s s i ng correc t l y wh ichqua dran t thetarg et would appear, th us,decreas ingthe re a c t i on ti me. Such
20
fragmentaryrules, if consciously acquired and implemented, wo u l dincreasethe pro babil i t yof re spondingcorre ctlyand quicklyon th e sevent hkeytri al. Thus ,th e info rmati o n that Lewickiet al. (1 9 8 7 ) were looking forth r o u g hth e awareness test may not bethe information that was re spon s iblefo r th e change in performance . That is, there would appearto be a viol a t ionoftheIn f o rma t i o nCri te r i on.
With respect to the Sensit ivityCr i t er ion, Shanksand St.Joh n (1 9 9 4 ) question whetherth e performance and awa ee n esa test e employe d by Lewicki etal . (19 8 7) were matchedwithrespec t tothe co nsci o u s information they were ableto pick up. That is, i tco u l d be the caseth a t the performancete s twas sensitive to the conscious in f o rmat i o n acquir e d th rou g h fragmentary rules, but the awareness test could not tap Incc this conscious infonnation . As a resu l t, the questionsposed duringthe awareness test wouldnotbe rel evant totl'.einformationemployed by the participants.
and that information would not be revealedby the participantsduring quest"Loning. Thus, dissociationcou l d have been erroneously attributed toun c o n s c i o u s acquisition of infor,'lIation .
Another study by Lewicki (1986)has et.ec beensu b j e c t e d to the scrutiny of Shanks and St.John(J.994). In order to decemunc whether information about covariations couldbe learnedimp l ic i t l y, Lewicki (J.96'6) exposed partic ipant s to picturesof peoples' faces. The experimentalmanipulation consist.ed of the covariation cecween hair lengthand personality characterist ics on the acquisitiontrials. All participants saw pictures of people with both short and long hair, as well as a brief personalitydescription. The covariationwithpersonalitywas manipulated in such a way that half the participants were exposed to long-haired people whose accompanyingpersonalitydescripticnel u d e d to a "kind" quality, and the other halfwereexposed to short- haired peoplewhose accompanying description eluded to a
"c a pa b l e ~quality.
During the test phase, participants were shown a new set of pictures and asked to agreeor disagree with statements that categorized the people in thosepictures as either "kind" or~capable". Resultsindicatedth a t parti cipantswere more likelyto confirmth e categorization when i t was consistentwith the covariationupon which they had been exposed to during the acquisition phase. These
22
results weretakenasevxeencethat eneparticipantshat1 uncon s cio u s l y ecqu tredthe relevant covariatio n betweenhai r length and personality .
Finally, duri ng the awareness test, participantswere askedi fcheywereawareof anyco-occur r encebetween the psychologicaldescripto.:=f')f the stimu lus pe op leand anyof their physical features . The pa r ti cipan ts gave no indic a tionthattheywere consciouslyaware of the existing rel at ions hipbet ween ha i r and pers o na lity suggesti ngthat thecova r i a t i o n had beenacqui r e d by the partici pants unconsciously. Sh,lnks and St.John (1994), howeve r, argue thatthere is noevide nc e that Lewi ck i (1986) has satisfied the SensitivityCrit eria . As was the cri t ici s m of Lewic ki
etal. (1987), itcou l d be tha t theacquisi tion test wasfar
moresensitive tothepart iclpanr:;;' con sc i ous knOWledgetha n wa s the awareness tes t.
In an attemptto replicatethe wor kof Le wi c ki et al. (1986).Stadler (1989 ) conducteda similar st ud y . Accordi ng to Shanks and St.John (1994) , th eSensitivity and Informa t.Lo nCri te r ia were met. The study repl i catedthe LE:/dckiet al. (1987j target location parad i gmwithone exceptacn , instead of the standa r d"qu e s tio n andans wer"
23
styl eawareness test, Stad ler (1989 ) empl o yeda trans fe r testcalleda ~pre d ic tiontask".
Inthepredic tiontask, thepar t i cipa n t swere shown similarblocksof seventria l s wherethetarge t locationon the seventhcompl ex trial couldbe dete rm i n e dby the sequence of fourpre c ed i ng si mpletrials. Onthe seventh trial, howeve r, the par tici pants were fa c e d not withan embeddedtarget, butfou r questionmarks placedin the four locations tha t cou ldpossiblyhousethe target. The participantswerethe nrequi r edtogue s s , without experimenterfeedback, which ofthefo ur quadrants the target woul d ap pear .
Becausethis predicti on ta s k made it possi b le for the pa r t i c i p a nt s to usewhatever consciouskno wledge th ey had ac quired (s e qu e n tial or fragm en t a ry ), the Information Crit e r ia was satis fi e d. Theexperimenterwouldnot be restrict:.ingawarenessquest ions to aspects that werenot re sp o n s i bl e for performancechange. Inaddition,because the predic tion task wasvery similarto the learningtrial s , Shank s andSt.John (1994) cont endthat the Sensit ivity Cri t eria was met, as both the acquisition and theawa reness
24
testwouldpickup on the same amount ofcon s c i ou s knowledge.
Stadler (19 89 ) replicatedthe finding of Lewicki ec al. (19 8 6) tha t over trials reaction time on complextarget tria l s signifi cantlydecreased. Pe r fo rma nc e on the pre d iction (a wa r e ne s s) tas k revealed the participants could corre ctlypredict ta r get locati ononly 11to 13 times out of 48. Thus, therewasnoevidencefor the subject's awarenes s of the rul e s. Shanksand St.John (1 99 4) sug ges t thatthe complexityofthe predi ctiontaskmay hav e caused the pa rti cipa n t s toforget what theyhadpreviouslylearned,due to interferenc e . Analternati ve explanation could be that the participantsacquired the relevantinfo rmat ion implicitly during the acquisition phase,but were unableto tr a n s f e r that information tothe novel complex trialus e d in the predic ti on ta s k .
The work of Reber (1967) a nd Reberand Lewis (1 977) has no t escaped th ecri t i cisms of Shanks and St.John (1994).
In the typical gr a mma r learningparadigm, parti cipantsare required tome moriz e a seriesof letter st ri ng s tha t are generatedfrom a rule-drivenartificial grammar . A control group is required to memorize similar, but random, letter strings . par ticipantsare then tested on novel strings.
25
Theyar ere q ui r e d toin di c a t e to the exper imenterwhether or no t thestri ng is-ee e e e e e » withinthe constraintsof the artificialgrammaror rules theyhave acquired.
participants in the rule-governedgroup perform wellabove chance and are unable to verballyreportthe rules usedto solve the task. The co nclusion drawnin these studies is thatthe partic i pantshave usedanunconsciousrule ind uc t i on mechanism.
With respect tothe Sensit ivityCriteria, Shanks and St. John (1994) arenot convincedthataretrospective verbal re po r t is sen sitive enough to test thecon sci ous kn owl edg e of rules. An alternativecouldbe con c u r r e nt thinkingaloud andrecogni tiontest sto increase the Sensitivitybet weenacquisitionandawa r e ne s s (Sha nk s &St. John ,1994 ). With re spe c t tothe vi ol a t i o n of the InformationCriteria, Shanks and St.John(1994) sugge s t tha t withinthe artificial grammarparadigm, the pa r t i cip a n t s may be le a r ni ng somethingother thanrules during the trainingtrials. Thus, toaskthepa rti cipa n t s to revealwh a t they hav e le a rned aboutrules duri n g the awarenesstest will in e v itablyre s ul t in fa l s e conclus ions.
Shan ks and St.Jo hn (1994) sugge s t tha t the partici;?antsin
"
these studies acquirethe information abou t the taskover trials vi a "... si mpl e memory mechanismsthat collect frequency st a ti s tics .. . " on occurringseque nc e s . Insuri09contonn ityto Iotormatjon and SensitivityCTH e r;a
It would app e arthat th e Informationand Sen s i ti v ity Cr i t eriaar e essential toresearchers who wi shto expl ore unconsc ious le a r n ing. To ensure that ne i the r of these cri t e r i a areviol a t e d . Shanks and St. John (199 4) sugge s t tha t eithe rthe tes t of awarene ssmustbe se n s i tive to all po tent i a lly releva nt con s cious information or be atle as t as se ns it i ve as the performanc e te s t indetect ingpot ent i ally rele va nt cons ciousinformation. The best sol u t ion is to make the awarenes s te s t as simila r as poss ibleto the performance test withre specttore tri e valcontext . Howev e r, the testsshoulddifferinterms of in s t ruc t i ons (Shanks&
St. Joh n, 1994) . The dnet ruct.L one for the awa r e ne ss test shouldencouragethe participant storetrieveas much informationas possib le. Given this format, it is unlikely that the parti c i pantswouldretrievemore cons cious info rmat ion on the performancetest thanthe awareness test becausethe instructions onthe awareness test are particularlymotivating (Sha nk s &St.John, 1994) .
27
A DeyelQpmenta l Perspective Qf UncpnsciQusle a rn i n g
From a developmental perspective, itisunqu e stionab le thatpr e -v er ba l childrenlearnwit ho u t ve r ba l awareness.
Forexample,at presc hoolage itisrelati v e l yee-ryto de mons trat e tha t grammat i cal informa t i on is acqui r e d intr ins i c ally. In her classic ·wug· st u d y , Berko (1958) demonstratedthat childrenas young as pre- schoo l age clearlypossessknOWl e dg e of mOl."phologic al rulesand can transferthat knowledge to novel artificialwords. By preschool children haveacquired and areca pa ble of using complex gramnar rul es without actuallybeing aware of the underlying st ru c tur e of thoserule s, thus indica t i ng impl i ci t acquis it i on of this linguist icknowledge . Based on the artificialgra rrmarstudies of Re ber(1967 , 1977 ) and the patternlearn i ng and covari ationstudi esof Lewickiet a!. (1986, 1987, 1988), the goal of thepresent study isto de terminewhether ornotolder childrenha ve the abilityto learn covariatio ninformat ionimplicitlyor explic itly .
The reis evidencefor children unde rs tanding covari ation s at a very ear l y ag e. Kuhn , Amsel, and O'Loughlan (1988) car riedout a set of ex pe rime nts to evaluate participantsabilityto understandthe rel a t i o ns h i p
28
between antecedent and outcome. Inthe s e experiments, it was demonstrated that children as young as eightyears old werecapableof understandi ng the covarf.ee ron between antecedent (cause) and outcome (effect) when directed to the realtionshipand askedto rate the extentto whichthe presence or absenceofa variable (e.g .component of a stain re mov al mi xture) will effect ou t c ome (e.g.whether or not the stain is removed) (Kuhn et al., 1988).
The ability of children to understand covariationsis also evidenced in a studyby Sodian (1991) (citedin Ruffman, Perner, Olson, &.Doherty, 1993). Children were told the story of a charac tertrying to determine whether the size of a tennis racketor the materials it was made
·from would affect the mannerin which the racketcouldbe used to serve a ball. In the sto ry, the cha racter de v elop e d anexperimentwhereby di ff e r e n t people ma de serveswith racketsthatvariedon onedimension whil e the othe r was heldconstant. At theendofthe character'sexpe riment, thech i ldren were shown ratingsof eachofthe rackets. The children were th e n re qu i r e d to explainto the experimente r howeach ratedracketeit her supp ort ed orref u t e dthe hypothes istha t it wa s size alone that hadthegr e ate s t
29
ef fe ct on serve. Thatis, the childrenwer e requ i r ed to demo ns trate an understanding of the covariation between a focal variable (s i z e ) and an optimum outcome (highquality serve) in ordertoprovidesupportingevidence for a hypothesis. Re s u l t s indicatedthat by the age of eight, more than halfof the childrenwereproficient at verbalizingan understandingof the relationship.
In a similar study ,Ruffman et al. (1993) set out to determine at what age children could understandcovariations that supporteda hypothesis infavour of a par ticu l a r cause for an observed effect. Four and five year oldchildren werefirs t introducedto a character "s a l l y" wholeft to "go play "shortlybefore the ta s kwa s to begin. The children were the n shown pi c t ure s of boys "eating" eitherred or green food;actuall y , the food was repres entedby piec es of colouredpaperlaid next to the pictures. All of the boys who wereeating re dfood had a fu llset of healthyteeth.
However, thos e whowere eating green food had several of their tee t h missing. The children were first asked to assess the covarf.atdon evide nceby te l lingthe exper imenter wh i c hfood makes kidste ethfall out. All of the children
30
answere dcorrectly, associat ing the correctcolour food with tooth loss.
Inthese c o nd phase, the childrenwere told that
"Sa lly " wouldbe returning . The experimenter thEm "faked"
the evidenceso that it now looked likethe red foodcaused tooth lossand the greenfood resultedin healthyte eth. The children were then asked wha t "Sal ly's" concl usionwould be given tha t the evidencewa s now faked. Acontro l ques tionfol lowed inorde r to de t erminewhetheror not the childrenhad change dtheir hypothe s e s. inlight of the fa ke d evidence even thoughthey we re tol d bythe expe r ime nte rwhat hyp othe sis was"t ru e". The re sult s ind i cat ed that the five year aIdsperformed well above chance, succassfully determining that changing thecovardeu s.oaevidence....ould alter the hypothesis for "s a lly ",but not for themselves.
The research of Kuhn etal. (1988), Sodian119911 and Ruffman et al. (1993 ) are byno means indicativeof children'sab ility to.!Ioc qui r e covariationinforma t ion impli c i t l y. In fact, the tasksadop ted inbo th st u d ieswere quite explicit, wi t hthe ch ild r e n clearl ydir ectedto the ex is t e nceof acovariation Iev t dence) withan accompan y i ng nypo t n e e f s . It does, howeve r ,demonstra te tha t ve ryyo ung
31
childrencan apprec iatetheconce p t that two variables(size and serve quality or food colourand tooth loss) must always occur together in orderto maintaina supported hypothesis.
To date, there islit t l epubli s he d material investigatingchildren'sunconsciousacquisitionof covariationinformation. However, in an unpublished manuscript, czyzewska, Hilland Lewicki (1991 ) found that four and five year old childrenwere able to impli ci t l y le a r n a covariation between the clothingcolour of children presented on posters and general categories (physically activeor physicallypass ive)of their activities (citedin Lewickiet al., 1992). Based on these findings, Lewicki ee al. (1992) concluded that veryyoung children are capable of learningcomplex contingenciesunconsciously.
More specific to the prese ntstudyis the workof RabinowitzandHowe (1994). InExpe r i ment 2, theylooked at the role of verbal awarenessand implicit learningin the acquisitionof the midd leconcep t (thatis, the conceptual middleas opposedto the posi tionalmiddle). participants ra ng i ng inage from 7to10ye a r s old were shownstimulus sets of threeit e mseac h , from whic h they wer ere qu i r e d to select theco n ce p tua l "middle "item. The pre t r a i ni ng sets
32
consisted of two setseachrepresentingarea (masoni te squares), number (numberof dots on a card), and height (woodendowe l s). Of these sets, paxt.Lodpant.ewere pretrainedon either one or two sets withi n the same dimension, ortwo sets from diffe rent di men s i o ns. Participantswere instruc t ed thattheywould be shown three items in a set ,andfromthatset they were to select the
"c o r r e c t " thing. They were not toldthe rule that made one item -ccreect e,but were told whether orno t they had made the correct choice.
After criterion had beenre a che d on pretraining, the children were exposed to 18 test sets (thetr a n s f e r task) representing physical dimensions(colour ,gap sizein the arc of a circle, el lipseshape) and cognitive dime n s i o ns
(age, body parts, story sequence). Thesedimensionswere novel and differedfro mthose the y ha d beentrained on, but still representedthe middlerule. In transfer, the chil d r e n were toldthat theywou l d view some new items, and i fthey thought about wha t they had learnedin the previous task theywouldbeable to determine the correct response.
They were not tol dwhetherthe y were right or wrongon the transfer tests. Once thetrans fer ta sk was completed, the
33
childrenwere asked how they had solved the problem. Those childrenwho indicated that the solution was "middle "or
"second" we r e classifiedas"e xt r i n s i c learners",as they had verba lly de s c r i b e d the middleru l e , while those who could give no indic a t i o n were classified as "intrinsic learners".
Both childrenclassified as "intrinsic" and "extrinsic"
learners wexe abletore a c h criterionduringpre training.
Such a finding provides further support for Lewickiet al. (199:2) who purport that ch ildrenare capable of ldarning complex contingencies int r i ns i call y . However, Rabinowitz and Howe (1994) alsofo undtha tin t ri n si c learnersre qu ire d more tria lsto reachcri t e r ionthan thoseparticipants cl<'lssified as extrinsiclearners. consequently ,it is questionablewhether or not thecog n i t i v e unconsciousis capable ofoperating fa s te r than the conscious, whichis a contentionofLe wi cki et ar . (1992).
With respect toverbal awareness for the middle rule, ch ildr e n who werepre tra i ned ontwo trai n ing se t s (either sameordifferen t dimens ions) we r e morelike l y thanchildren trainedon only one training-setto extractthe mi ddl erule anddemonstratethisknowledgewithve rbalawareness.
34
Moreover, onlythos e partici pantswho demonstratedverbal awareness of the mi ddle rule (tha t is, theexplicit le arners) we r e able eotransferthat rule on the test trials. If, asLoftu s and Klinger (1992 )contend , that a smart cogn it iveproc e s s is one thatca n deal flexiblywith novelsitua t ions Un thi scase, the transfertask) then conscious learners ,withinthe Rabinowitz and Howe (1994) paradigm, were smart. Unfort unately, the poo r transfer per fo rma nceof the imp lici t learne r s len d s no suchevide nce fora smart unconscious. These re s u lts appeartofa vou r Greenwa ld (1992) anda relativelyunsophisti cated unconscious.
Transf erTaakas a Me t bpd for Inc reaaing se nsi ti v i t y The transfertaskadoptedby Rabinowitzand Howe (1994) has meritas a mechanismto addressthe Sens itivity Criterion . Shanksand St.John (199 4) conte ndthat the sens itivi tyCriterionis violatedwhen the evarenesetest cannot detect ccaectcue inf o rma tio n that may be responsible for the change inperformanc e. By using a tr an s fer task, an ad di t ionalsou rceof in f o rma t i o nbecomes avail abl ewhich can be compa redwi th tha t obtai ne d fr om the awa re ness test. Since the transfer test. employs the same met hodol ogyas the
35
trainingtask, a "s e nsLt. I ve " performance measure would also impact conclusions.
The introductionof the transfer taskpr ov i d e s alte rnat ives fo r interpreting the results. With a transfer task,a new set of st imuliareshownto the participants.
Although the stimuli are new, the "ru le" is stil l the same as that which was used to solve the pretraining t.aek. using this paradigm, the re are severalpossible outcomes. First, part icipants cou ld transferand dis p l a y verbalawareness, thus showing a smart conscious that can deal flexibly with novel situations. Second, participantsmay be able to transferbut be unable to demonstrateverbal awareness. Such a findingwould provide evidence for a smar t unconecdoue that can transfer informa tionindependent of conscious awareness. Third, pa r t i c i p a nt s may be unable to transfer but be ableto demonstrateverbal awareness. This wouldbe indicative of a rather dumb conscious. Finally, partici pantsmaybe unable to transfer andunableto de mons t r a t e verba l awareness , consequently showing adumb un cons c i ous.
36
Atria-DugeaGajped byIJa "jP9 Childparticipapts
Mos t st ud iesof implicitlear ning have invol ve d adult pa rti cipantsandhighl y comp l e xta s k s (Berry&Broadbent, 1984 ; Broa db e nt&Aston, 1978; Broadbentet al.,198 6;
Lewicki et al., 1986, 1987, 1988, Reber et al., 1967, 1977 1 . Clearly with an adult population, th ele a rning taskemployed will be more comp l e x thanthose used instudies involving children . A highlycompl ex taskcarrieswi t h it the oppo r tuni t y forparticipa ntstosolvethe problem byme a ns other tha n that intended bythe ex pe rimente r. Thisproblem resul t s in violat i onof the Information Cr i t e rio n put forth byShanksand St.John (1994) and is preciselythe basi s upon whichthest ud i e s of Lewicki et al. (19 86 , 198 7 )and Re be r (1967; 1977 )havebeencrit icized . TheIn f o rma ti on Criterionrequiresthe expe rimentertoestablishthat the informationsought through the awareness test is indeed the in f o rma t ion responsibleforperformance change in the participants (Sha nk s& ae.John ,1994) . By usingadu lt participants, and the necessarily complex ceeks, firm conclusionsabou t imp l icit learning are lesslike l y than whenthe task empl oyedisle s s complex . The complexity of the task employed inadult studiesmay provideparticipants
37
wit.h cons c iou s knowledge of alterna t i ve sol utions that the experi menterdid not int en d and subs equent.l y isnot access ed throughlateraware ne s s tests. With child parti c ipants, t.he taskserr.pl oyed areles s complex, re lat i v e tothoseempl oy ed with adu l t participants . For thi s reason, ch i l dren are bett e r part i cipa nt sin st udie s that lookatthe uncon s c i ou s C\cqu isit ionof in form a t i on. Byus i ng childparti ci pa nts , and simpler le arn i ng tasks forwh ichthe r e arefe wer ecrue t c ne , improvedperfo rmance canbe att r i bu ted to the int e nded rul ewit h grea te r confide nce. Inaddit ion , be ca u se themaj ority of impli cit lea rning st ud i eshave inv olved adul t population s, it isinteres ti ng tolo ok at children in order todetermi n e what sor t of dev elopme n t a l trends exist in implicit learni ng.
Overview
The pr e s e nt studywa sde si gned todetermine how childreningrade s four andfivelearncov aria tions, and whe the r thenumber of irrel evant di men sionspr e s ent in st i mu l us setswoul dfaci li t a t eimplicitlearning.Seger (1994), based ont:indi ngs reportedby Lewi ck i et al. (l987 ) and Kush ner et ef. (1991) , con j ectured th atir re levant aspe ctsof stimu l i may be dealtwithmore ef fi cient ly by the
3 .
implicit system. Sege r (1994) sp e culat e d thOlt the reason for thi s could be tha t the explic i t tho ug h t system has mor e difficu ltydetermining wh ichstimuli canbeignored. The impl ici t lea rnin gsyste m, onthe other han d , appear-atobe lessaffe cted by irre l ev an t informa tionpresu mably beca u s e it can determine thedependencie s betwe e n alarger number of va r iabl e s thantheex p lici t system (Seger, 1994).
Alternative l y, it maybe that the explici t le a rn i n g system is especiallyse nsi tiveto irrelevantinf o rma t i o n because the explicit sys tem engages in hypothesistesting. For example , itis pos sible to generatea largenumber of ne w hyp o t he s e s when an irrel ev an t dimensionis add e d to a dis criminat ion lea rning task (s eeGho l son , 198 0 ) .
The foll owi ngpredictions are based on theconjecture thatthe explicitsys t em engages in conscious hypothe s is testing thr oug h seria l process ing qf stimulu s
ch a r a c t e ris tics. Wi th eac h addi t i o nal two-value d dimens i on presentin stimulus items, ifall pos sible hyp othes e s are tested, the numberof hypothesestotest increases by a power of two, thusincreasi ng the difficultyof the task and the amount of processing. The proc e s s i ng engagedin by the implicitsys tem, on the othe rhand,isconjectured to be
39
assoc iat i ve',perhaps automat i c , and parall el. Inother word s, eac h addi tional two-val ue ddime ns i o nspresen t in st imulusitems woul dbeproce ssed si multa ne o u s l y, or in paralle l. Hen ce, the amoun t of processingrequiredbythe implici t systemwoul dno t inc r e ase tothe same extentas that requi r edbythe exp l icit sy s t em engag ing inse ria l pr o cess ing . Therefore , the learni ngra t e ofthe implici t system will decrea seat a slower rate than tha t of the explicitsystemas task difficultyincre as es .
Fourth - and fifth-g r a de r s we r e chosenLnlightof the re s e arch of Rabino wi t zand Howe (1994 ) andtheres u lts of a pilotstudy' , both of wh ich demons trated thedifficu lty that thir d gr a de child renhavereach i ngcrite rion,verb alizing rules,and transferringin f ormati o n. In their investiga tion of the role of ver bali z a tioninthe acquis ition of the middleconc ept, Ra binowi tz and Howe (1994) foun d that the percentage of fou rthand fifth grade r s who wer eve rba ll y
'1bel'l'\l.'O;of diellJ"~lDnenl due~11111 dependon associativeprOCes.~illg,btullulttheprceessesinvolved in implicit and explidlleamilll1: are differell/.
~!ll,kll.'lCdin dJepiIOl: lItudyprovedlobeloocornplelt for the lrade tbree ebi1d ren wi lhonly " " relll:bing nilcriorl.itW"M lktcnninedthe gflllleJIIllII1flIeImll1dnolherepm;entalivelwedon lUehapoorsuccessrate.Therefore, Jra<J<: 0&ehildren W<:re choscnin.m...
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aware (expli citle a rn e r s ) differed signif icantly fromthird gt"a ders, withmorefourth -and fifth-graders th a n thi r d - graders verbally statingthe middlerul e. Rabinowitz and Howe(1994 ) also showed that only thosech ild r e n who ve r b al ized the rule were able totransfer the conce pt te s t trials. It wa spredicted thatonl ythos e children who demonstrated ver b al awareness ofth e covariation rulewould be successfulin the transfertask.
Given theassumptionthat the implici t learning sy s tem engages in parallelproce ssingand subsequentlyappears to be less affec ted by irrelevantinforma tionthan theexplicit syst e m, i t was also predicted that thepercentage of par tic i pants le arni ng implicitly (wi t hou t ve r bal awareness ), as co mpa r e dtoexplici t ly,wouldin crea s e as a functionof the numberofir r e levant trai ningdimensions. In addition, si nce the implici t learningsystemis assumed to be less affected by ir r e l e va nt information, impli citlearners tr a i n e dontwo irrelevant di me ns ions would be expectedto showsmal lerincreases inthe numberof tr ial stocr i t e rion during training than explicit learners .
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Method part icipan ts
The participants were 112 elementarysc ho olchildren. Parental and school board consent were required in order for children to participate. Childrenwere chos e n from two grade levels; those who did not reach criterionwere replaced. Sixty-one fourth- and 52 fifth graders were needed to yield 48 children (24 male and 24 female) who reached criterionat each grade . At the grade four level, five children failed to reach criterion when trainedon one irrelevant dimension; eight children failed to reach criterion on two irrelevantdimensions. At the grade five level,one childfailed to reach criterion whentrained on one irrelevant dimension; th reechildren failed to reach criterionon two irrelevant dimensions. The mean age of grade four childrenwas 114.54months with a standard deviationof 4.90months;the mean age of the grade five children was 129.48 months witha standard deviation of 19 . 8 3 months.
The design was a grade (four and five) by genderby treatment (one and two irre levantdimensionson training)
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factor ial. Twelve pa r t i cip an t s werequasi-randomlyassigned to each cell . Thede pe nde nt vari a b leswere errors to criterion', thenumberof correct resp o nses made on the transfertask, responselatency on the criter~onrun, mean responsela t e n cy during transfer, and verbal awareneaa. SUml1li
.n:.a...ini.ns. The treatmentconditionsdiffered inthe trainingsets employed. In both conditions, children were trained on setsof thr ee stimuli varying in size (large or small) andshape(curved or straight) (see Figure la). Of these three stimul i, only one representedthecovariation between shape and size (e.g. ,cu rvedandlarge). Of the four possible combinationsof size and shape, only three wereusedinthe stimulussets presen tedto a particular SUbject. Those used possessed at least one of thecue values thatde fi ne dthe covariation (e.g ., one that is curved andsmall, one thatislarge and straight, and one that is both curvedand large- the covariation l. The features which definedthe covariationwer e counter -balanced over participants. Thus, for 25% of the participa ntsin
'Analysesconducted onbo!lIerrorstocriterionand trialstocriterionyielded5imil~rresults.
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each cel l, the covariaeion wassmall and straight, for 25t thecova r i a t i o n was small and curved, for 25t the covariationwas large and st r a i g h t , and forthe remaining 25' the covariationwa s large and curved.
Du ri ng training, both groupsof participantswere exposed to ava ri e t yof tra ini ng sets in which the covar-LacIcn rule was represented. Thiswas ac c omplishedby using three-sided figures duringtr a i ni ng which were varied ra ndoml y betweentr i a l s interms ofleng t h of sides, whether the curved si de was convexorco nc a ve, and definingangleof the isosceles triangle {30, 60, 90 , 120 deqz-ee sL.
Partic ipant sin the one irrelevantdimensioncondi t ion experiencedthe stimulus sets describedabo ve. Within tr i a l s , th e stimuli differedin size (large or small),shape (cu rved or straigh t ) , and position onthecompu t e rsc r e e n (left , middleor right). Size and shape were there a e ve n t dime ns ionsde t e rmini ng the covariation, whilepos i tio n was an irre levantdi me n s i o n. For the two irrelevantdimensions participants, the stimulusdi me n e f o n e (size, shape, and position)als~"va r i e d withintrials. Inaddition, the two ir r e l e va nt di me ns i on groups wereexposedtoanother irrelevantdi me nsio n , stimuluspattern,whichva r i edwithin
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trials (see Figure Ib). Thus , thesepa r ticipa nts experienced two irrelevantdimensions - pos itionof the stimul us on the screen and stimulus pattern . Stimulus pa t t e rn refersto the way in which the insideof the shape was patterned. The cue values used to representthe pat tern d.imension were sol id-tilled (thest i mul u s sha pe was coloured in completely), stripes (t he stimulus shape had stripes runningthrough it) , andunfill ed (thesti mul u s sha p ewas le f t unpat t e r ne d l .
Tx:a.D.af..e.r:. The covariationbetween shape andsizewas maintainedon thetran~fertask. However, insteadof the three-sidedfigures usedin training, rcur-sidedfigures wereused (s e e Figure2). The participants we r e expos ed to four stimulus se t s, whic h consisted of either three squares, thr e e parallelograms, three rhombus e s, or th r e e irregular quadrilaterals. Each of the sets was presented six times duringtr a ns f er generatinga to t a l of 24 transf e r tr i a ls. Oneight randomly determined trialsthe irrelevantdimension ot positionwas present; on ano the r eightrandomly determined trialstheirreleva n t dimensionof positionand the ir relevant pattern dimen s ionwas present; and on the final eight ra nd oml y determined trials the ir relevant
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dimension of position, the irrelevant pattern dimension, and an additional third irrelevant dimension was present. This third irrelevant dimension involved the number of lines (one, two, or three) projecting from the top of the stimuli.
As in training, length of sides, whether the curved side was convex or concave, and the position of the correct stimulus was randomized for each subject.
The participants weretested in their schools. The stimuli were presented via computer. A button box, with three buttons representing the three stimuli on the screen, was used for the participants to indicate their choices. During training, the children were told: "Each time you will see three things on the computer screen. One of them will always be correct. Ifyou choose the correct thing you will see a "check" over yourchoice. Ifyou choose the wrong thing you will see an "Yo" over your choice." The appropriate word, either "correct" or "incorrect" also appeared at the bottom of the screen. No additional feedback was given. The training criterion was nine correct responses in any successive ten trials.
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Inmediately after reach ingcriterion, the transfer te s t was presented . The children weretol d: "Now youwill see somenew thi ngs on the computerscreen. Ityouthi nk about wh at you just le a rn e d , the nyou willbe able to choosethe cor r e ct thingeach time. Thistime thou gh, th e co mpute r will not tell yo uwhetheryou are rightor wr o ng ."
Aftercomplet ingthe trans fer task, the children were givena verbalawarenesstest,designedarounda four·point scori ngsys tem(s e e AppendixA.l. Child renwere first asked:
"Howdidyou solve the probl em?" Ifth e y cor rer.~ ly identifie d the covariation (e.g., "It wasalwaysthe la rg e curve d one." ) . theywerescored a threeand questioning ce a s e d . I fthe ycorrectly identifiedonlyon eme mbe r of the covariati on, (e.g.•"Ye s.The largecnessl , theywe r e asked ,
"How doyou know this? Therewere two larg eone s."
Following this question . if theyco r r e c t ly id e nt i fi e dthe seconddimensiontheywere scored a two, otherwiseth e y receiveda one .
Childrenwho incorrec tlyanswe redthe firstque s t i o n (i.e. "How di d you solvethe pro bl em?" )were sco r e d zero , while children who failed togive anyans wer to thi s question werepr ompte dby the question"Di d you no t i ce that
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any parti c ula r ~of objectwascorrec t ?" Ifthe ythen cor rec t lyidentif ied the covariat i o nthe y weresco red a three. I fthe y cor r e ct ly defi n e d only one member of the cova ria t ion, the y were as ked"Howdoyou know this; ther e wer etwo ldime nsions)?" . If th eycorre ct l yanswered that question , theywerescored a two , otherwise they werescored aone. Parti c ipa n t swho gave a wronganswertot.heprompt.ed question, or failed toanswer t.he question at. allwere scored zero.
Results
The ma in focu s of this stud y wastosee howindividual dif f erence s in awar e ne s saffectcovari a tion learning and tra ns fer. preliminary ana lyse s were conductedinorderto determinewh ichvariablescoul dbeeli min ated from subs equ e n t analyses. It wa s expect ed that there wouldbean une qu a l distribut i on of pa r ticipan ts' awaren e s s scores ac r ossgrade, and thenumberof ir r ele va nt dimensions duri ng tr ai n i ng. Preliminary ana l y s esare de s cribedfirst , in order to jus t if y the eliminat ionof thebe t we e n - s ub j e ct s vari a ble genderand justify the re a s o n i ng behindthe re scaling of theverbal awareness measurefor subsequent analyses. Furtherref erencesto preliminary analyses will
.8
