Associative recognition: A case of recall-to-reject processing

16 Pages·2010·1.78 MB·English

Memory & Cognition
2000.28(6).907-922
Associative recognition:
A case of recall-to-reject processing
CARENM. ROTELLO
UniversityofMassachusetts, Amherst, Massachusetts
and
EVANHEIT
UniversityofWarwick,Coventry, England
Two-processaccountsofrecognitionmemoryassumethatmemoryjudgmentsarebasedonbotha
rapidlyavailablefamiliarity-basedprocessandaslower,moreaccurate,recall-basedmechanism.Past
experimentsonthe time courseofitemrecognitionhave notsupportedthe recall-to-rejectaccountof
thesecondprocess,inwhichtheretrievalofanolditemisusedtorejectasimilarfoil(Rotello&Heit,
1999).Inthreenewexperiments,usinganalysessimilartothoseofRotelloandHeit,wefound robustevi
denceforrecall-to-rejectprocessinginassociativerecognition, forwordpairs,andforlist-discrirnination
judgments.Puttogether,theseresultshave implicationsfortwo-processaccountsofrecognition.
Oneofthe key issuesinrecognitionmemoryresearch ficiently weakthat aresponse(oldor new, respectively)
is the nature ofunderlying processing, such as whether maybe madewith confidence, However, ifthe familiarity
there is more than one process involved and what each ofthe item cannot support a confident decision, a sec
process accomplishes. According to single-process ac ondary processisused(Atkinson& Juola, 1973, 1974).
countsofrecognition(e.g.,Estes, 1994; Gillund&Shiff Mostrelevanttoour work, thereisresearchsuggesting
rin, 1984; Heit, 1993; Hintzman, 1988;Nosofsky, 1988), that fastermemoryprocessingrespondstoglobalaspects
judgmentsare basedonaunitaryassessmentofstrength, ofthe teststimulus,whereasslowerprocessingisaffected
correspondingto the summedsimilarity ofthe test item by the finer details ofthe stimulus. This result has been
toall the relevantitemsinmemory.Single-processmem demonstratedinanumberofexperimentsusing aresponse
ory models have been shownto account for a wide vari signalprocedure.Inthisparadigm,asignaltorespondoc
ety ofdata (seeClark& Gronlund, 1996, and Raaijmak cursavariableamountoftime (typically, 100-2,000msec)
ers & Shiffrin, 1992,for reviews). afterthe onsetofateststimulus,andthe subjectisasked
A growing body ofresearch, however, suggests that to make ajudgmentquickly after the signal. Using this
recognitionjudgmentsmay involveasecond, recall-like methodology,Dosher(1984)hasshownthatwhensubjects
process(e.g.,Atkinson& Juola, 1973,1974;Dosher, 1984; study word pairsthat are unrelated to one another(e.g.,
Gronlund & Ratcliff, 1989; Hintzman & Curran, 1994; king-pear; house-queen),theytendto false alarmto re
Humphreys, 1978; Jacoby& Dallas, 1981; Jones& Heit, arrangeddistractorpairsthatare semanticallyrelated (e.g.,
1993; Mandler, 1980; Ratcliff& McKoon, 1982, 1989; king-queen)forfasterresponsesignals-say,withinabout
Yonelinas,1994;seeMandler, 1991,forabriefreview). For 600 msec ofstimulus presentation. At longer response
example, one dual-process account assumes rhar recog lags, however, subjectscorrectlyrejectthesesemantically
nitiondecisionsare basedon the familiarityofthe target related pairs (for related work, see Ratcliff& McKoon,
item ifthat familiarityiseithersufficientlystrongorsuf- 1982, 1989). Incontrast, new items that are not similar
to presented stimuli and are not semantically related to
each other are correctly rejected even in very rapid re
sponses(see Gronlund& Ratcliff, 1989). Similarly, Hintz
This researchwas supportedbyGrantSBR-9753136from the NSF
man andCurran(1994) reportedthatsubjectswho stud
and byaFaculty ResearchGrantfromtheUniversityofMassachusetts
toC.M.R. underthenameCarenM.Jones. Thisresearchwasalsosup ied listsofstimuliofvaryingplurality(e.g.,frog, trucks)
portedbyagrantfrom the Biotechnologyand BiologicalSciencesRe tend to false alarm to highly similar foils (frogs, truck)
searchCounciltoE.H. and Koen Lamberts.WethankScottGronlund, earlyinthe timecourseofjudgmentbut tocorrectlyreject
WilliamHockley, MichaelHumphrey,andSandyPollatsekforinsight
those test stimuli laterinprocessing. These studies sug
fulcommentsonthis work, Neil Macmillanand ArnieWellforstatis
ticaladvice,andSonya DougalandChristineHigginsforassistancewith gest that the familiarity ofa stimulus is usedas the first
stimulusmaterialsanddatacollection.Correspondenceconcerningthis basis ofresponseandthatarecall-likeprocessmaybeused
articleshouldbesenttoeitherC.M.Rotello,DepartmentofPsychol for sloweror moreaccurate recognitiondecisions.
ogy, Box 37710, UniversityofMassachusetts, Amherst, MA 01003
Thisevidencepointstotwo mechanismsthatunderlie
7710(e-mail:[email protected])orE.Heit,DepartmentofPsy
recognition,butlittleresearchhas directlyaddressedthe
chology, UniversityofWarwick,CoventryCV47AL, England(e-mail:
[email protected]). specific natureofthe presumedrecall process. Wethink
907 Copyright2000 Psychonomic Society, Inc.
908 ROTELLa AND HEIT
it is crucial to address specific versions oftwo-process alsobeconsideredwhenevaluatingthe presenceofare
accounts, rather thanconsideringthisissueatalevelthat callprocess. Saythatearly inprocessing,false alarmsto
is too general to make sharp predictions. Rotello and similar foilstendtoincrease, whereaslaterinprocessing
Heit (1999) described several possible ways in which a theytend todecrease. Suchapatternoffalse alarmshas
recall processcouldoperateinrecognitionmemory. For sometimes been taken as general evidence for a recall
example, anexhaustivesearchrecallprocess would work likeprocess(e.g., Hintzman& Curran, 1994).However,
by searching through memory for a memory trace that itisnormallyacceptedthathitratesand false alarm rates
matches the test probe. Successful location ofa match shouldbeinterpretedwithcaution,becausehitsandfalse
would leadtoitsacceptanceasastudieditem; failure to alarmsdependnotonlyonsignalstrength,butalsoonre
find amatch would leadtotherejectionoftheprobe,re sponse bias. In atypical response signal experiment, in
gardlessofhowfamiliaritseemed.Arecall-to-acceptre which a subject might sometimes have to respond after
call process would supplement a familiarity-based pro 100msec and, othertimes, haveas muchas2,000-msec
cessbyincreasingtheprobabilityofanoldresponsewhen torespond, asubjectmaywellhavedifferentresponse bi
amemory tracematchingtheprobe isfound. Such apro asesatdifferentdeadlines. Hardlyanyinformationwould
cesswouldnotinfluencetheresponsestotestfoils,which beavailableearly inprocessing,soalenientcriterionfor
would presumably be based on their familiarity alone responding old might apply. On the other hand, when
(seeRotello&Heit, 1999,fordetails).However,thedom further informationisavailable,astrictercriterionmight
inantconception oftherecall-likeprocess isthat itwould beineffect.Indeed, RotelloandHeit(1999) reportedsig
provide mismatching information from memory so that nificant changes in bias measures as a function ofre
testfoilsthataresimilartostudieditemsmaybecorrectly sponse signal lag. However, we note that statistical as
rejected and called new (e.g., Dosher, 1984; Yonelinas, sessmentofwhetherbiasischanging,ornotchanging,is
1997). This type ofprocess has been called a recall-to complex when sensitivityord'isalso changing,asinthe
reject process (Clark, 1992, p. 241; Clark & Burchett, caseofresponsesignalexperiments(Macmillan& Creel
1994,p.57;Gronlund& Ratcliff, 1989,p.857;Hintzman man, 1991).
& Curran, 1994,p. 14;Rotello & Heit, 1999;seeClark& Insum,usingadifferencescoresuchasd hastwomain
L
Gronlund, 1996,pp. 56-57, for areview). That is, when advantages over uncorrected measures, such as false
asubject istestedonasimilarfoil,thecorrespondingold alarmrate. First andmoreimportant,itisatargeted mea
item isrecalled, leadingthe subjecttoreject the foil. sure ofrecall-to-rejectprocessing, ratherthan ageneral
The recall-to-reject account makes a distinctive pre measure ofasecondaryprocess. Second,becauseitis,in
diction, unique amongthese possiblerecall processesin essence,thedifferenceinresponse totwoitemsatagiven
recognition,when asimilaritem, suchasfrags, istested response signaldeadline,anyresponsebias itselfshould
but the wordfrag was studied (Rotello & Heit, 1999). becanceled out. Weemphasizethat the issue ofchang
Whenfragsistested,theolditem,frog,isrecalled, butthe ingresponsebiasissecondary, however.This difference
similaritem,frogs,cannotberecalled. Intheface ofthis
mismatching evidence,frogs is rejected and is given a
judgmentofnewregardlessoftheoutputofthesimilarity
based recognition process. This recall-to-reject process
would not affect adissimilaritem, such as chair, which
isnotparticularlysimilartoanypresenteditem. Indeed,
such acompletelynew item would likely be rejectedon
thebasis oftherapid similarity-basedprocess.Thus, the
Old
differenceinfalsealarmstofrogs andtochairshouldde
crease lateinprocessing(say,afterabout600-700msec,
basedonpastresearch),asthesecondprocesshelps peo
ple torejectfrags, relativetochair. These differencesin
false alarms canbecomputedasd'sor,forconvenience,
asdLS, whichindicatethe standardizeddistancebetween
themeans ofthetwoputativenormal(d')orlogistic(dL)
distributions ofmemory strength.' Dosher (1984) used
such an analysis for recognitionjudgments, referringto
themeasureaspseudo-d';morerecently,thismeasurehas
been used for similarexperimentsbyDosherand Rose
dale(1991),GronlundandRatcliff(1989),Hintzmanand
Curran(1994), RatcliffandMcKoon(1989), and Rotello
andHeit(1999).Figure 1presents therecall-to-rejectpre
diction, interms ofdv in idealizedgraphical form.
Other performance measures, such as the false alarm
Figure1.Idealizedpredictionoftherecall-to-rejectaccountof
ratetosimilarfoilsasafunction ofprocessingtime, could recognitionjudgments,intermsofdL•
ASSOCIATIVE RECOGNITION 909
scoremeasure istargetedatrecall-to-rejectprocessingre ciative information" (p. 713). Several memory models
gardlessofwhetherresponse biaschangesatdifferent re treatthe storageofassociations betweenitems inessen
sponse signals. tially the same wayasthat forindividuallystudieditems
(e.g., Hintzman, 1988)andassumethatbothitemandas
Evidence RegardingRecall-to-RejectProcessing sociativeinformationareretrievedfrom memorysimul
Rotello and Heit (1999) assessed the evidence for taneously(e.g.,Gillund& Shiffrin,1984;Hintzman,1988;
recall-to-rejectprocessinginitemrecognition,usingdata Pike, 1984;seeClark&Gronlund, 1996,forabriefsum
fromHintzmanand Curran(1994,Experiments2and3), mary). Although these models can accommodate addi
as well as data from two new experiments. In each ex tional assumptionsabout recall processes,theydonotat
periment, subjects studied lists ofstimuli and then were presentassume that recall ispartofassociative recogni
asked to make recognitionjudgments ina response sig tion.Weseethevalueofthesemodels, infact,asshowing
nalparadigm. There werethreetypesoftestitems:(I)old whatcanbedonewithoutbuildinginrecall-likeprocesses
items that had appearedon the study list; (2) new items whentheyarenotactuallynecessarytoaccountforresults.
thathadnotbeen studiedandwereunrelatedtoanystud Nonetheless, many differences have been found be
ieditems;and(3)similaritemsthathadnotbeen studied tweenitemandassociativerecognition. Forexample,low
butweresimilartostudieditems.Acrosstheexperiments, frequency wordsaretypicallybetterrecognizedthanhigh
similaritems were defined either as nouns that differed frequency words inanitemrecognitiontask (seeGregg,
inpluralityfrom the studieditems(e.g.,frogs, whenfrag 1976,forareview),butinanassociativerecognitiontask,
had been presented)oras pseudowordsthat were ortho eitherthereisnofrequencyeffect(Hockley,1994)orhigh
graphicallysimilartostudied pseudowords (e.g., PRUMIR, frequency wordsarebetterrecognized (Clark, 1992;Clark
whenPRAMADhad been studied). Noneofthe analyses in & Shiffrin, 1992). The associative recognition data are
any ofthe four experiments showed evidencefor recall moreconsistentwithfrequency effects inrecall(see,e.g.,
to-reject processing. More specifically, no decrease in Sumby, 1963)than with those in item recognition. Sim
the rateofacceptanceofsimilaritems wasfound laterin ilarly,instructionaleffectsonassociativerecognition and
processing, aswould bepredictedbythe recall-to-reject free recall performancealsoparalleloneanotherandare
account. Similar foils were not being increasingly re differentthantheeffectsforitemrecognition. Whensub
jected,relative tocompletelynewfoils, assubjectswere jectsaretold tostudywordpairs inpreparationforanas
allowed more time to make their judgments. Although sociativerecognitiontest,rather than anitemrecognition
there may be some results that are generally suggestive test,their associativerecognition improves,buttheiritem
ofmultiple processes,our analyses specificallytargeted recognitionisunaffected(Hockley& Cristi, 1996).Anal
thedistinctivetime course predictionforrecall-to-reject ogously, subjectswhoexpectarecall test ofstudiedma
processing. Now that these strict tests have been devel terials have betterrecall scores than those whoexpect a
oped,weintendtoapplythemtoothertasks thatmaywell recognition test, but the twogroups haveequivalent rec
lead torecall-to-rejectprocessing. ognitionperformance(May& Sande, 1982).Results like
One task in which recall-to-reject processing is per these led Clarkand Gronlund(1996) toargue that recall
haps more plausible isassociative recognition. In asso wasmore likelytooperateinassociativerecognition than
ciative recognition, two items or events are recognized in item recognition and, moreover, that it was likely to
as having occurredtogetherat some pointin the past. If operate inarecall-to-rejectfashion.
pairings ofevents are mutually exclusive, it may be as Several other studies haveprovidedevidence sugges
sumedthatrecallingthatoneeventhadoc-curredwiththe tiveofarecall-to-rejectprocessinassociativerecognition.
test cue precludes anotherevent's having occurredwith Perhaps the most compellingdata come from anexperi
the cue. More concretely, ifyouare asked whetherJohn ment by Humphreys (1978, Experiment I). Humphreys
ismarriedtoMary,recallingthat Susan isJohn'swife is evaluatedwhetherrecognition ofassociatedwords (i.e.,
sufficientevidence to recognize that John and Mary are intact, A~B pairs) could be predictedfrom the probabil
not married. Several researchers have proposed that as ityofrecallingBgivenA asacue and the probabilityof
sociative recognition includes a recall-to-reject process recognizingBintheabsence ofothermemory cues. Sub
(e.g., Clark, 1992,p.241;Clark& Burchett, 1994,p.57; jects studied pairs ofwords (A~B) and then recognized
Gronlund & Ratcliff, 1989, p. 857; Humphreys, 1976, old (B) and new (X) words. Finally, halfofthe subjects
1978;Mandler, 1980). However,they have not provided took an associativerecognitiontest inwhich intact pairs
distinctive time course evidence for the recall-to-reject (A~B)and old-newpairs (A~X)were presented.There
mechanism. maining subjects were given a cued recall test, with the
Indeed, there are reasons to predict that no evidence Awords asretrieval cues. Performanceintheassociative
wouldbefoundforarecall-to-rejectprocess inassociative recognition condition waswellpredictedbytheprobabil
recognition. Itmayseem unlikelythatthere isadifferent ityofaBword's being recognizedand, ifBwasnotrec
mechanism for pairs ofwords than for single words. ognized, the probabilityofits being recalled whencued
For example, Hockley (1994) has argued from experi with A. The close match between the observed and the
ments onthe mirroreffect that "similarretrievalandde predicted data in the associative recognition task sup
cision processes underlie recognition ofitem and asso- ports the hypothesisthat recall isinvolved inassociative
910 ROTELLa AND HEIT
recognition. However, Humphreys' data do not speakto inHintzman& Curran, 1994,and Rotello& Heit, 1999),
the time coursepredictionsforarecall-to-rejectprocess. weseeafailureoftherecall-to-rejectaccount.Again,we
Morerecentsupportfor theuseofrecall-to-rejectpro are focusing on the mostappropriate measure ofrecall
cessing in associative recognition comes from receiver to-reject processing, rather than assessing other mea
operating characteristic (ROC) data (Rotello, Macmil sures thatare not targetedatthis specific accountofthe
lan,& VanTassel, 2000;Yonelinas, 1997).InYonelinas's recall process. On the basis ofpast work, there is some
(1997)experiments,subjectswere askedtodiscriminate reason to think that recall-to-reject processing may be
intact pairsofwords(i.e.,thosethathad beenstudiedto more likely inassociativerecognitionthaninitem recog
gether) from rearranged test pairs in which both words nition. However, this pastwork for the mostpartdid not
had been studied, butnot as partofthe same pair. (De addressthe timecourseofjudgments,nordid itapplythe
parting from standardterminology, Yonelinas, 1997,la targeted,difference-scoremeasurethatismost appropri
beledthose rearrangedpairs new.) Yonelinas (1997) ar ate for assessing recall-to-reject processing. Therefore,
gued that sometimes subjects were able to recall that inthis paper,weareapplyingthe analysesinRotelloand
rearrangedpairshadnot beenstudied,becausethey could Heit to associative recognition, to betterassess the evi
recall that they had been paired with other study part dencefor recall-to-rejectprocessing.
ners. The evidencefor thisclaimcenteredon the (cumu Experiment 1replicated the critical aspects ofGron
lative) false alarmrate thatwasassociatedwiththe upper lund and Ratcliff's(1989) Experiment2 withasubstan
portionoftheROC.Specifically,"ifsubjects recollectthat tially largernumberofsubjects.Wealsosimplifiedtheir
20% ofthenew[i.e., rearranged]pairsarenew,thentheir design. Concurrentwiththeassociativerecognitiontask,
falsealarmrateshouldnot exceed80%"(Yonelinas, 1997, GronlundandRatcliff'ssubjectswere givenanitemrec
p. 752). Indeed, under conditions in which recollection ognitiontask. Thatis,theirstudylistsandtest lists were
ofstudiedpairswas relativelyeasy(i.e., eachwordwas mixturesofindividualwords and word pairs.This design
pairedwithonlyonestudypartner;shortstudylists),the may have focused the subjects' attentionon the individ
cumulative false alarm rate declined, as comparedwith ual words in the study pairs, ratherthan on the associa
an experiment in which study lists were long and study tions. Such afocusonindividualstudyitemsmightmake
words had multiple partners. Rotello et al. (2000) re the task somewhatsimilartoanitem recognitiontask,in
cently showed that this decline in the cumulative false whichrecall-to-rejectprocesseshave not beenfound. In
alarmratetorearrangedpairsoccurs onlyunderconditions ourfirstexperiment,the subjectsstudiedand weretested
inwhichthe recallprocesshas timeinwhichto operate. only on wordpairs.
For recognitionjudgments made veryquickly, in which In our Experiment 2, the subjects again studied only
the familiarity-based process was assumed to dominate pairsofwords,butthey weretestedonwordpairsaswell
the decision, no evidence for recall-to-rejectprocessing as single words. We examined whether recall-to-reject
emergedinthe ROC data. processingdependedonstudyingpairsofwordstogether
Finally, there is someevidencecollectedoverthe full orwhetheritwas afeatureofassociative(i.e.,word pair)
timecourseofjudgmentthatissuggestiveofarecall-to recognitionjudgments.Finally,wecontinuedalongthese
rejectprocess. Gronlundand Ratcliff(1989)askedsub lines inExperiment3,inwhichthe subjectsstudiedonly
jects to discriminate intact and rearranged test pairs; in single words, but in two different list contexts. The re
addition, they presented subjects with new test pairs in trieval task was associative in that the subjectsjudged
whichneitherwordhadbeenstudied.Theirdatasuggest whetheraparticularword occurredina particularlist.
thatpeoplemaybe increasinglyable torejectsimilar,re
arrangeddistractors,relativetocompletelynewfoils, after EXPERIMENT1
about600-700msecofprocessingtime. Thatis, intheir
publishedfigure, the falsealarmstotherearrangedpairs Method
appearedtodecreasemorerapidlyovertime thandid the Subjects. The subjectswere 14membersofthe University of
false alarmstocompletelynew foils, perhapsindicating Massachusettscommunity, mainlyundergraduates,whowerepaid
the presence ofa recall-to-reject process in an associa fortheirparticipation.Anadditional 3volunteersparticipated,but
theirdatawereexcludedfromtheanalyses because theyfailed to
tive recognitiontask.
discriminate studiedtest pairs fromcompletelynewpairs evenat
thelongesttest lags.
Overview
Stimuli. There were 3,600 words(3,100 nouns, 500 verbs) se
Wesee experimentson the time courseofrecognition lectedfromthe Francis andKucera(1982)wordfrequency norms.
judgments, using methods such as the response signal Thewordswere3-11 lettersinlength,withinitial letterscovering
technique,asbeing crucialforassessinganymultiprocess theentirealphabet, andwereselected without regard tolinguistic
accountofrecognition.Therecall-to-rejectaccountmakes frequency.Other thanlength,thetwoconstraintsonselectionwere
thattherecouldbenoobvioussynonympairsrepresentedonthelist
adistinctivepredictionfor responsesignalexperiments,
and that an average University of Massachusetts undergraduate
in terms ofa difference score comparing responses on
wouldbelikelytorecognize eachword.
similarfoils andcompletelynewitems. Tothe extentthat The3,600stimuluswordswererandomlyorganized intopairsfor
this prediction is not supported by particularresults (as eachsubject.Thewordpairswerethenassignedtooneof50study-
ASSOCIATIVE RECOGNITION 911
testblocks.Eachblockconsistedofastudylistof27pairsofwords Table 1
presentedoneatatime for4secandatestlistof27pairs. Oneach MeanHit andFalseAlarm(FA)Rates
test list, there were 9 intactpairs from thejust-studied list, 9re forthe Stimuliin Experiment1
arrangedpairsfromthatlist,and9pairsmadeupofcompletelynew ResponseSignalLag(msec)
wordsthatwereneverstudiedinanylist.Therearrangedpairswere
Type 100 300 500 750 1,200 2,000
generated bycombining the left-hand word from one study pair
Intact(Hit) .12 .31 .53 .70 .75 .78
withtheright-handword fromanother study pair,maintainingthe
Rearranged(FA) .19 .21 .34 .29 .19 .19
left-rightordering. The studypairsfromwhichtherearrangedtest
New(FA) .15 .09 .07 .05 .03 .04
pairswerecreatedappearedinrandompositionsonthestudylist.
Sixtestlagswereused(100,300,500,750,1,200,and2,000msec),
sotherewasonetest trial ofeach type(intact, rearranged,new)at
each testlag. Ineven-numberedblocks, the3remainingtrials oc tory responses or additional uncontrolled processing of
curredat the 100-, 500-, and 1,200-msec lags; in odd-numbered the stimulus."
blocks, theyoccurredat the 300-, 750-,and 2,000-msec lags. So, For completeness, weprovide the hit rates and false
withineachexperimentalsession(i.e., 10blocks)there were IStri alarm rates for the intact, rearranged, and new pairs in
alsofeachtypeateach lag.Acrossblocksandsessions(excluding
Table I. These valueswereadjustedbyadding 0.5tothe
Session Iaspractice),there were60trialsofeach type ateachlag
numberofyes responses and dividing bythetotal num
foreachsubject.
The order ofpresentationofboth study and test pairs was ran berofresponses +1.0,sothatdLcould becalculatedlater
domlydeterminedforeachstudy-testblockforeachsubject.Tomin (Hintzman& Curran, 1994;Rotello & Heit, 1999;Snod
imizelistinterference,eachstimuluswordappearedinonlyonestudy grass & Corwin, 1988).There aretwonotable aspectsof
pairand/oronetestpair intheexperiment. the data. The false alarms to rearrangedpairs increased
Procedure. Eachsubjectparticipatedin5-h-longexperimental earlyinprocessing(i.e.,untilthe500-msec response sig
sessionsoveraperiodofseveraldays.Atthebeginningofeachses
nal)and then declinedlaterinprocessing. Although this
sion, there was ablock of36training trials inwhich the subjects
peaked pattern offalse alarms to similar or rearranged
practicedrespondingintheresponse signalprocedure. Foreachof
the36trainingtrials,theywereshownanorientingcue(->+<-)cen teststimuli couldbetakenasevidence ofthecontribution
teredonthecomputermonitorforIsec.Thecuewasreplacedbythe ofrecalltorecognition,therawscoresmustbeinterpreted
wordyesorno,whichappearedonthescreenforavariable amount withcaution,becausethefalse alarmstocompletely new
oftime(100,300,500,750, 1,200,or2,000msec)before beingre pairsdeclinedcontinuouslyacrossprocessingtime.That
placed byamask (?????). Atthesametimeasthe mask appeared,
is,the subjects' decision criteriaappeartobecome more
abriefsignaltonesounded,signalingthatthesubjectshould press
conservativeastheyareallowed more timetomakerec
Iifthewordyeshadappearedand0ifnohadbeenpresented.They
were instructedtorespondas quickly aspossible after the signal, ognition decisions,although weagain notethatthisissue
eveniftheyhadtomake aguess. However,accuracyfeedback was isdifficult toassessstatisticallywhensensitivityischang
providedoneachtrial,andlatencyfeedbackwasprovidedonlywhen ingaswell (Macmillan& Creelman, 1991).
the response occurred too quickly after the signal (i.e., less than Next, we calculated acceptance rates (dL) for intact
50msecafterthesignal) orwhenitoccurredtooslowly(i.e.,more
andrearrangedpairsbycomparingtheoldresponserates
than350msecafterthesignal). Therewere6trainingtrialsateach
on these items to the oldresponse rates to completely
ofthesixtestlags;halfwereyes, andhalfwereno.
newpairs. Theresults oftheseanalysesareshownasthe
Afterthepracticetrials, eachsession wasmade upof10study
test blocks. The 27 pairs ofstudy words were presentedone ata data points in Figure 2. The subjects were well able to
time,centeredonthescreen,ata4-secrate.Immediatelyfollowing discriminateintacttestpairs from completelynewpairs:
thestudylist,thesubjectsmade27speededrecognitionjudgments Theacceptanceofintactpairs,relativetocompletelynew
about pairsofwords from that study list.As inthe practicetrials, pairs,risescontinuouslytoahighasymptote.However,the
each testtrialbegan with anorientingcue,which wasreplacedby
subjects showedanonmonotonicfunctionofacceptance
atestpairthatremainedonthescreenforavariable amount oftime
forrearrangedpairs.Thatis,acceptanceofrearrangedpairs
(i.e.,oneofthesixtestlags)beforebeingreplacedbythemask.At
the sametime as the mask appeared, asignal tone sounded, indi increased early in processing and then declined later in
cating tothesubjectthatanimmediateresponse wasrequired. The processing. These data appearto be consistent with the
subjectsweretoldtorespondyestotestpairscontainingwordsthat predictionsoftherecall-to-rejectaccount(compare Fig
hadappearedtogetheronthestudy list(i.e., tointact pairs) andto ures Iand 2).
respond notoallotherpairs. Asinthepracticetrials,the subjects
Thereareseveralwaysinwhichthese d datacouldbe
wereurgedtorespond immediatelyafterthesignal;theyweregiven L
evaluatedstatistically.Mostobviously,ananalysisofvari
accuracy feedback oneach testtrialandlatency feedbackafter re
sponses thatweretooslowortoofast.Thesubjectswereinstructed ance could be conductedonthe data, and post hoctests
totakeself-pacedbreaks betweenblocks. or trend analyses could be used to evaluate whether the
acceptance ofrearranged pairs (relative to completely
Results newpairs) showsapeakearly inprocessing(see Rotello
Data from the first session foreach subject weredis & Heit, 1999).Abetter focused analysis wouldusenon
cardedaspractice trials. Allanalyses werebased ononly linear estimation procedures that capture the pattern or
those responses thatoccurredbetween 100and350msec shapeofthedata.Thatis,thedatacanbefittedwithmath
after the response signal. Responses outside that win ematical functions thateitherdoordonothaveapeaked
dow,13.3%overall, wereconsideredto reflectanticipa- shape. Ifthe fit isstatistically betterwith apeaked (i.e.,
912 ROTELLa AND HEIT
nonmonotonic)functionthanwithanonpeaked(i.e.,mono tion's fitted values are shown in Figure 2 as the curves
tonically increasing) function, there wouldbe distinctive superimposedon the data.
evidenceforarise-then-fallpatterninthedata.Weadopted Thesemodel-basedanalysesfocusedonaveragegroup
this curve-fittingapproachfor ourpresentanalyses. responses,ratherthanonindividual subjects' responses.
Todeterminewhetherthedropinacceptanceofthere Itisusefultolook atgroup responses,particularlywhen
arranged pairs at the laterresponse signal lags was sta notmuchdatahasbeen collectedforeach individual,but
tisticallysignificant,thedatainFigure2werefittedwith thereissomeriskthattheaveragedgroup-levelresponses
twoseparatefunctions. The firstfunction representsmo maynotcaptureallthecharacteristicsofindividualsub
notonicgrowth toalimit (Ratcliff, 1978): jects'data.Toevaluatewhetherthegroup responseswere
indeed representative ofthe individuals', the data from
AI
dL(lag) = ,(l) individual subjectswere also fitted with bothfunctions.
VI +v/(lag - 8) Ofcourse, these data were necessarily noisier, possibly
makingitmoredifficulttofindareliablybetterfitforthe
where lag is the response signal lag plus the latency to
nonmonotonicfunction. Nonetheless,for4ofthe 14sub
respondatthat lag(i.e., total processingtime), AIisthe
jects,the nonmonotonic function fit significantlybetter
asymptotic level ofdiscrimination, vis the rate ofap
than themonotonic function. Withan a = .05 criterion,
proachtothatasymptote,and 8isthepointatwhich dis
theprobabilityof4ormoresignificantresultsoutof14,by
criminationrises abovechance.The second function we
chance alone, isless than 1%.Also, itispossibletosum
fit to the data is a nonmonotonic function ofa similar
up the evidence for the nonmonotonic model obtained
format. It assumes that the data conform to Equation 1
until aparticularpoint inprocessingtime, lag*,atwhich foreachindividualsubject. Theadditionalextentofdata
fittingprovidedbythe nonmonotonicmodelcanbe rep
pointdiscriminationbeginstodeclinetoasecondasymp
resentedasachi-squaredstatisticwith2degreesoffree
tote, A2' (Because we were interested specifically in a
dom(seenote5).Thesummation ofthesestatistics would
rise-then-fallpattern in the acceptance data, the param
also haveachi-squareddistribution, with 28 degrees of
eterswereconstrainedsothat thesecondasymptotewas
freedom. The obtained value for the summation across
no higherthan the first.) The nonmonotonic function is
subjectswasX2(28) =66.88,p<.001,indicatingthatthe
given by
total improvementoffitthat wasduetothe nonmonoto
A2+(AI - A2)(lag* - 8)/(lag - 8) nicmodel was significantlygreaterthan chance. Hence,
dL(lag) = ---r=======--- whenapplyingthemodelstoindividualsubjects'data,the
VI +v/(lag - 8)
results supportedthe analyses based on groupaverages.
forlage lag*. (2) (SeeRotello & Heit, 1999,forfurtherexamplesofthese
analyses.)
Equations 1and 2(and variants) havebeen widelyused
(e.g., Dosher, 1984;Gronlund& Ratcliff, 1989;Ratcliff,
1980;Rotello& Heit,1999;Wickelgren& Corbett, 1977). Discussion
Foreachtypeofstimulus, distinctratesandasymptotes Mostcritically,thesubjects showedapeakedpatternof
wereestimated,butasingleintercept(8)wasused forall acceptancefor rearrangedtest pairs, asafunction ofre
thestimuli toreducethe numberofparameterstobefit.' sponse deadline, providing evidence for recall-to-reject
Model fitting was performed using SYSTAT'sSimplex processing. Apparently,retrievingoldwordpairs didhelp
estimationmethod to iterativelyadjust parameters so as the subjects to reject rearranged word pairs. In contrast
to minimizethe residual sum ofsquares (RSS). The fits to these results supporting recall-to-reject processing,
tothesedataconfirmedthevisuallyobservableconclusion Rotello and Heit (1999) found no evidence consistent
ofanonmonotonicacceptancerate forrearrangedpairs. withrecall-to-rejectprocessing inseveralitemrecognition
Although the monotonic fit was quite good (R~djusted = experiments. This difference may be surprising in light
.986,RSS=.981),4thenonmonotonic fitwassignificantly ofpastaccountsthatrecognitionofitemsandassociations
better [R~djusted= .990, RSS = .515; X2(2)= 7.733, p < isdependentonthe same underlyingmechanisms.How
.05].5The best-fitting parameter values for both func ever, as we argued earlier, a number ofdifferences be
tions are shown inTable2, and the nonmonotonic func- tweenitemandassociative recognitionhavebeenreported
Table2
Best-FittingParameterValuesfor theMonotonicand
NonmonotonicFunctions,FittoDatafromExperiment1
MonotonicModel Nonmonotonic Model
Type Intercept Asymptote Rate Intercept Lag· Asy.1 Asy.2 Rate
Intact 497.6 5.78 341.5 493.6 1,105.3 5.83 363.2
Rearranged 497.6 2.14 31.0 493.6 1,105.3 2.76 1.39 106.9
Note-Asy. 1,theearlierasymptote;Asy.2,thelater(lower)asymptote.
ASSOCIATIVE RECOGNITION 913
55
•
•
4.5
3.5
::J
3
Q)
c0 25
co
0.
Q)
0
0
<{ 15
0.5
-05
0 500 1000 1500 2000 2500
Lag + RT (ms)
Figure2.Mean acceptancerates,intermsofdL,for the intact(circles)and
rearranged(squares) test pairsin Experiment I. Thecurvesshowthe best
fittingnonmonotonicfunctions.
(e.g., different effects oflinguistic frequency), many of Heit(1999).Ontheotherhand,ourownaccountisthatthe
whichareconsistentwitharecallprocess'splayingalarger natureofassociativeretrievalitselfwouldfacilitaterecall
role inassociative recognition than initem recognition. to-reject processing. That is,when tested on rearranged
Our next two experiments were designed, inthe first pairs, subjects will be able to readily recall old pairs of
instance, as attempts to extend and replicate the results words and use this information to reject the rearranged
supporting recall-to-reject processing. Experiment I is pair.
perhaps the most distinctive time course evidence for In Experiment 2, the subjects studiedpairs ofwords;
recall-to-reject processing to date, and it did seem use then they were tested both on word pairs and on single
ful to try to replicate this singular result. Experiment 2 words. Thus, the subjects had an associative encoding
was intended to explore furtherthe differences between task, followed byatest ofassociative recognition (as in
itemrecognition (norecall-to-rejectprocessing)andpair Experiment I) and ofitem recognition. Our prediction
recognition (recall-to-rejectprocessing). Whatisitabout was that recognition performance would be suggestive
associativerecognitiontasksthatwouldleadtorecall-like ofrecall-to-reject processing forword pairs, replicating
processes? Does studying items in pairs facilitate later Experiment I, but that recognition would not indicate a
recall-like processes? Past research has indicated that second recall-like process for single items, replicating
the manner inwhich information isencodeddoes affect RotelloandHeit(1999). Suchresults wouldindicate that
retrieval in several ways. For example, experiments in recall-to-rejectdoesnotdependonstudyingpairsofwords
whichsubjects study pairs ofwordsandareinstructedto but, rather, on being tested onpairs ofwords.
formeitheravisual imageofeachwordorasingle image
ofthewordstogetherhaveshownthatrecognitionofthe Table3
individual words(i.e., item recognition)tends tobebet StimulusStructurefor Experiment2
ter under separate imagery instructions, whereas asso StudyPairs TestStimuli Type
ciative recognition isbest under interactive imagery in
A-B A-B Intactpair
structions(e.g., Begg, 1979;McGee, 1980).Inaddition, C-D C-F Rearrangedpair
studying pairs ofwords differs from studying single E-F X-V Newpair
G-H G Olditem
words interms ofmemory load (on the surface, there is
I-J I' Similaritem
twiceasmuchinformationbeingencodedforwordpairs,
Z Newitem
ascompared with single words). Perhapsthe changesin
Note-Thisstructurerepresentsoneseventhofastudy-testblock;,in
the study task inExperiment I could havebeen respon
dicatessemanticrelatedness(synonymy)betweentwostimuliwiththe
sible for the different results from those ofRotello and samelettername.
914 ROTELLa AND HEIT
EXPERIMENT2 Results
The data from each subject's initial session were ex
Method cluded as training trials. In addition, we excluded re
Subjects.Therewere 13volunteersfromthesamepopulationas sponses that were less than 100 msec or more than
thatinExperimentI.Theywerepaid$8foreachoffiveexperimen 350 msec after the response signal, because those data
tal sessions. Oneadditional subject's data wereexcludedbecause includeanticipatoryrespondingoradditional uncontrolled
fewerthanathirdofthe responsesweremadewithin 350msec of
processing.Thetrimmingprocessexcluded20.4%ofthe
the response signal andthe remainingtrials revealed chance-level
data, which suggests that this experimental task, with
recognitionatthelongest test lags.
Stimuli.ThebasicstimulusstructureisshowninTable3.Essen intermixeditem andpairrecognition, wasmore difficult
tially,the subjects studied lists of35 word pairs and were tested than thestraightforwardpair recognitiontask in Experi
onintact,rearranged, andnew wordpairs, aswellasonindividual ment I(forwhichonly13.3%ofthedatawereexcluded)."
studiedwords, synonyms ofstudiedwords, and completelynew The mean hit and false alarm rates to both pairs and
words.
itemsare shown inTable4.AsinExperiment I, oneno
The stimuli were3,298 words selectedfrom the larger pool of
table aspectofthe data isthe systematic decrease inthe
wordsusedinExperimentIand245synonympairs(e.g.,attorney
lawyer;rabbit-bunny)that were selected fromtheWhitten, Suter, false alarm rate to new pairs and to new items as the re
andFrank(1979)norms(the setofsynonyms didnotoverlap with sponse signal lag increases. Also noteworthy is the ap
the largerpool ofwords). From the largerpool,2,808 words were parent increase in false alarms to rearrangedword pairs
selectedandrandomlyarrangedintopairs,someofwhichservedas earlyinprocessing, followedbythe substantialdecrease
studypairsandsomeofwhich werereserved foruseascompletely
inthose false alarms later inprocessing. This patternof
newtestpairs. Anadditional 245 wordsfromthelarger pool were
respondingissuggestiveofalaterecall-likeprocessthat
selectedatrandomandservedasthecompletelynewfoilsonitem
recognitiontrials.Fromeachsynonympair,onewordwasselected allows rejectionofsimilarfoils.
atrandom andassignedtobestudiedwith oneofthe245 remain The acceptance rate (in terms ofdL) for test pairs is
ingwordsfromthelargerpool (itwasrandomlyassignedtotheleft shown inFigure3,asafunction ofresponse lagplus re
orrightposition within thepair);theotherwordineach synonym action time; corresponding results for single items are
pairservedasasimilardistractorontheitemmemorytests.
shown in Figure 4. Consistent with past research (e.g.,
Foreachsubject,thewordpairsweredividedevenlyinto35study
Humphreys, 1976, 1978),recognitionofindividual words
lists of35pairs each. The presentationorder ofthepairs on each
thatwerestudiedinpairs issomewhatlowerthan recog
studylistwasrandomizedforeachsubject.Foreachstudylist,acor
respondingtestlistwascreatedsothatthere weresevenintacttest nition ofthe pairs. Perhaps the most striking aspect of
pairs,sevenrearrangedtestpairs,sevennewtestpairs,sevenstudied thesetwofigures, however,isthedifferenceintheshape
test words, sevenunstudiedsynonyms,and sevencompletelynew ofthedL curves. Whereasthepairdata,showninFigure3,
words.Onetestitemofeachtypeoccurredateachofthesevensig lookquitesimilartothedatafromExperiment I,theitem
nallags (i.e., 100,300,500,750, 1,000, 1,250,and 2,000 msec).
recognition data look quite different. As was predicted,
Thetestorderwasrandomizedforeachlistandforeachsubject. For
the pair recognition results show the distinctive peaked
thetestpairs,wordsalwaysappearedintheiroriginal left-rightor
dering. Forthetestitems, thetest wordofagivenstudiedpairwas patternofrecall-to-rejectprocessing,butthe itemrecog
selectedatrandom from the leftand rightwords. Across lists and nition data do not. (The results in Figure4 do appearto
blocks(excludingthoseinthefirst session),therewere28testtrials becomparablewithitemrecognitionresultsreportedby
ofeachtypeateachresponsesignal lag. Rotello &Heit, 1999.)
Procedure.TheprocedurewassimilartothatofExperiment I,
Next, weconductedmodel-basedanalysesofthedata
withonlyminorchanges. First,thesubjects weregiven42practice
fromtheassociative recognitiontask.Thatis,wefittedthe
trialsatthebeginningofeachexperimentalsession,6ateachofthe
seven possiblesignal lags (100,300,500,750, 1,000, 1,250, and monotonicandnonmonotonicfunctions (Equations Iand
2,000msec).Second,thesubjectsweretoldtorespondpositivelyto 2)tothedatainFigure3.Although themonotonicfitwas
test pairs only ifthey had studiedthe words togetheron the list, good (R~djusted =.976, RSS =.796), the fit ofthe non
whereastheyweretoldtorespondpositivelytotestwordsiftheyhad monotonic function was significantlybetter [R~djusted=
studiedthewordsinanypair. Forallothertestitems, they were to .988,RSS = .265; X2(2) = 15.398,p < .001]. The best
respond negatively.
fittingparametervalues forboth functions are shown in
Table5,andthepredictionsofthenonmonotonicfunction
Table4 are shown as the curvesinFigure 3.
MeanHit andFalseAlarm(FA)Rates Wealso conducted model-based analyses ofthe data
forthe StimuliinExperiment2 from the item recognition task. Although the nonmono
ResponseSignalLag(msec) tonic fit was good (R~djusted= .962, RSS = .425), itwas
Type 100 300 500 750 1,000 1,250 2,000 not reliably betterthan the monotonic fit for the data in
Testpairs Figure 4 [R~djusted = .968, RSS = .455; X2(2) = .955,
Intact(hit) .30 .32 .48 .59 .57 .59 .60 n.s.]. The best-fitting parameter values for both the
Rearranged(FA) .28 .26 .38 .41 .40 .38 .25 monotonic andthe nonmonotonicfunctionsareshownin
New(FA) .26 .26 .15 .14 .15 .15 .14
Table5,andthepredictionsofthemonotonicfunctionare
Testitems
Old(hit) .25 .36 .50 .61 .58 .60 .58 shown asthe curvesin Figure 4.
Similar(FA) .29 .26 .28 .29 .25 .26 .21 Finally,wefit the monotonicandnonmonotonicfunc
New(FA) .26 .27 .23 .22 .24 .21 .16 tionstoindividualsubjects'data.Those datawereneces-
ASSOCIATIVE RECOGNITION 915
30
•
2.5
20
::J
:g
1.5
oQ)
-c
(1j
0. 10
Q)
o
o
«
0.5
00
-05
0 500 1000 1500 2000 2500
Lag + RT (rns)
Figure3.Mean acceptancerates,intermsofdL,for the intact(circles)and
rearranged (squares) test pairsin Experiment2.Thecurvesshow the best
fittingnonmonotonicfunctions.
30
25 •
2.0 •
•
::J
:g
15
oQ)
c
2
0. 1.0
oQ)
o
«
05 ~ !§
,-.-..------------
§1
•
00
-05
0 500 1000 1500 2000 2500
Lag + RT (rns)
Figure4.Meanacceptancerates,intermsofdL,fortheold(circles)andsim
ilar(squares)testitemsinExperiment2.Thecurvesshowthebest-fittingmono
tonic functions.
916 ROTELLa AND HEIT
Table5
BestFittingParameterValuesforthe MonotonicandNonmonotonicFunctions,
FittoDatafrom Experiment2
Monotonic Model NonmonotonicModel
Type Intercept Asymptote Rate Intercept Lag* Asy.I Asy.2 Rate
Associative recognition
Intact 506.0 2.72 113.7 505.7 1,406.0 2.73 119.1
Rearranged 506.0 1.51 0 505.7 1,406.0 1.84 .46 48.7
Itemrecognition
Old 504.0 2.10 82.0 475.2 654.4* 2.59 466.0
Similar 504.0 .40 18.9 475.2 654.4* .22 .22 521.5
Note-Asy. I, theearlierasymptote; Asy.2,the later(lower)asymptote. *Multiplevaluesofthisparam-
etermakethesamepredictions. Asamplevalueisshown.
sarily noisier than the overall means (they were also miliarcues that had not been encodedtogether. Wepre
noisierthan the individual data from Experiment 1,be dictedthatthesubjectsinthisexperiment wouldshowevi
causeonlyhalfasmanyassociativerecognitionjudgments dencefor recall-to-reject processing, becauseofthe as
were collected). Nonetheless, ofthe 13subjects, 3 had sociativenature ofthe retrievaltask, eventhough, strictly
associative recognitiondata that were significantly bet speaking,the subjectsonly studiedsinglewords. Weare
ter fit bythenonmonotonicmodel. There wouldonly be not the first to argue that a list discrimination task is a
a 1.1% chance ofthree ofthese outcomes resulting by type ofassociative recognition: Indeed, classicwork on
chancealone. Forthe item recognitiondata, only 1sub recognition memory has emphasized the parallels be
jecthad data that were significantlybetter fitted by the tween list-specificrecognitionjudgmentsand word pair
nonmonotonic model (p > .35). In addition, the incre memoryjudgments,intermsoftheassociativenatureof
mentalfit ofthenonmonotonic model, summedover all bothtasks (Anderson& Bower, 1974;Hintzman, Block,
thesubjects'individual fits, washighlysignificantforthe & Summers, 1973).
recognition ofwordpairs[X2(26) = 65.749,p< .001]but Two similar studies have been conducted recently.
wasnotsignificantforitemrecognition [X2(26)= 38.160, First,YonelinasandJacoby(1994,Experiment3)hadsub
n.s.]. These analysesofindividualsubjects' data fit well jectsstudy sets ofword lists and then make list-specific
with the analysesfor groupaverages. recognitionjudgments.This experimentusedaresponse
signal procedure, but with only two test lags (600 and
Discussion 1,600 msec). Although the false alarms to completely
Most importantly,this experimentreplicatedthe find new items did not differ with response signal lag, false
ings from Experiment 1suggesting recall-to-rejectpro alarms towords fromthenontargetlistdecreasedslightly
cessingforwordpairsandlikewisereplicatedthefindings fromthe600- tothe 1,600-mseclag.This patternofdata
ofRotelloandHeit (1999)thatdid notfind evidencefor isconsistentwith adecreaseinsimilar-newdiscrimina
recall-to-rejectprocessingforsingle words.Notably, Ro tionthatwould be indicativeofarecall-to-rejectprocess.
tello and Heit's main analyseswere forexperimentsthat However,YonelinasandJacoby didnotreportd ord', so
L
used pseudowords and words that differed in plurality. the predictions ofthe recall-to-reject account could not
Hence,thesefindings foralackofrecall-to-rejectprocess beevaluated.
ing in the case ofitem recognition ofsynonyms are an Morerecently, Hintzman,Caulton,andLevitin(1998)
extension ofRotello and Heit's reported results. It ap reportedlist-discriminationexperimentsthatalso used a
pearsthatthedifferencebetweenitemrecognitionandpair response signal paradigm.IntheirExperiment1,subjects
recognitionisnotsome consequenceofsimplystudying studiedlistsofwords andweregivenalist-discrimination
words inpairs; rather, recall-to-rejectprocessing seems test after each study list, so that List 2on test trial n be
to be particularlyfacilitatedbytestingonpaireditems. came List Iontrialn+I.Someofthetest words occurred
InExperiment3,weagainattemptedtoextendourre onlyinList 1;othersoccurredonlyinList2;therestwere
sults,herebyusingadifferentkindofassociative retrieval eithercompletelynew orhad been studiedon both Lists
task. Insteadoftestingsubjectsonword pairs, however, 1and 2. They did not report dLsfor the nontarget list
we asked the subjects to study individual items on two items, as compared with completely new foils, but the
separatestudy lists(List Iand List2)andgavethemlist patternofdata shownintheir Figure 2 suggeststhat the
specificrecognitiontests. Hence,wecreatedanassocia false alarms to words that had been studied on the non
tive recognition task by asking the subjects to respond targetlist(i.e.,familiarwordsthatweretoberejected)de
positivelytowordsthat were associatedwith atargetlist creasedmore rapidlyovertime than did the false alarms
andtorejectbothnewwordsandstudiedwordsthat were tocompletelynew items. That is,theirdata providesome
associated with the other (nontarget) list. These latter support for our predictionthatan item recognition task
items were comparablewith the rearrangedpairs in Ex that requires list discrimination would involve a recall
periments I and 2, which likewise put together two fa- to-rejectprocess. However,theirtaskwasrathercomplex;