Journal of Experimental Psychology:Human Learning and Memory1979, Vol. 5, No. 5, 460-471

Remembering In and Out of Context

Steven M. SmithUniversity of Wisconsin—Madison

Three experiments examined the incidental associations between list-learningmaterial and the environmental context of that list's presentation. The envi-ronmental reinstatement effect is that subjects remember more when testedin their original learning environment relative to those tested in a new envi-ronmental context. Experiment 1 demonstrated that this effect is due to amemory process, rather than a general performance decrement caused by theunfamiliarity of the new test room. The reinstatement effect was eliminatedin Experiment 2 when subjects tested in a new room were instructed torecall the original learning environment just prior to free recall of listwords. This release from contextual dependence was diminished in Experi-ment 3 when the original learning room was made more difficult to remem-ber. The results show that context effects can be brought under cognitivecontrol; subjects can supply their own contextual retrieval cues when thecontext can be easily recalled.

Contextual dependence of memory refersto phenomena which show that memory isbest when the situational or contextual con-ditions present at learning are reinstated atthe time of the test. Such phenomena havebeen documented for various memory para-digms and for a variety of types of context.(For reviews, see McGeoch, 1942; Smith,Glenberg, & Bjork, 1978.) For example,words are recalled more poorly when theenvironmental context is changed (differentcontext [DC] condition) rather than heldconstant (same context [SC] condition)between input and test (e.g., Godden &Baddeley, 1975; Smith et al., 1978). Similardecrements in verbal memory have been

The experiments presented are based on a dis-sertation by the author. This research was sup-ported by the U.S. Public Health Service GrantMH22643 to A. M. Glenberg.

The author is indebted to Arthur Glenberg forhis help and guidance on the project. Thanks arealso due to William Epstein, Gregg Oden, MarianSchwartz, and Thomas Ward for their helpfulideas and suggestions.

Requests for reprints should be sent to StevenM. Smith, who is now at the Department of Psy-chology, University of Oklahoma, Norman, Okla-homa 73019.

noted with changes in semantic context(e.g., Light & Carter-Sobell, 1970) andwith changes in pharmacological state (e.g.,Eich, Weingartner, Stillman, & Gillin,1975).

Context dependence, however, has failedto occur in certain investigations (e.g.,Farnsworth, 1934; Santa & Lamwers, 1974;Smith et al., 1978, Experiments 4 and 5),and such failures cannot necessarily beattributed to experimental insensitivity or toa lack of statistical power. It is apparentlynot enough to state simply that SC condi-tions produce better memory than DC con-ditions, if one wishes to predict memoryperformance. What is needed is a more com-plete framework or set of principles todescribe the interrelation and functioningof context in memory processes. Such aframework should be capable of predicting,for example, how to enhance or to decreasecontextual dependence through manipulationof the type of material learned, type of con-text, type of test, or instructional variables.It is the aim of the present investigation topoint out one such principle of contextualfunctioning that relates memory for contextto the phenomenon of contextual dependence.

Copyright 1979 by the American Psychological Association, Inc. 0096-lSlS/79/OSOS-0460$00.7S

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REMEMBERING IN AND OUT OF CONTEXT 461

The present studies are specifically con-cerned with the effects of the general en-vironmental context on memory of verbalmaterial acquired in that situation. The gen-eral environmental context refers to thephysical surroundings in which an eventoccurs, including location, size of room,objects and persons present, odors, sounds,temperature, lighting, and so on. The typeof contextual dependence dealt with in thepresent investigation, to be referred to as theenvironmental reinstatement effect, is thefinding that subjects recall more when re-turned to their original learning environ-ment, as compared with those tested in anew environment (e.g., Smith et al., 1978).

The environmental reinstatement effect,an empirical phenomenon, should be dis-tinguished from the theoretical principle(e.g., Carr, 1925), which states that con-textual associations are responsible for theeffect. Contextual associations refer to con-nections in memory between what is learnedand the environmental context in whichlearning takes place. For example, con-textual information might be associated witheach list word (e.g., Anderson & Bower,1974; Kintsch, 1974), with the list of words,as a whole (i.e., the search set model, Smithet al., 1978), or with the set of cognitiveoperations employed for processing andcataloging learned information (e.g., Still-man, Weingartner, Wyatt, Gillin, & Eich,1974). The meaning of the term contextualassociations here is not further specified be-cause the hypotheses relevant to the presentset of studies do not discriminate among thevarious possible meanings.

It is not obvious that subjects store con-textual associations in memory because therehas been no systematic relationship betweenthe environment and list words in any con-text studies. Experiment 1, therefore, exam-ined the possibility that the environmentalreinstatement effect is caused by an experi-mental artifact, rather than the result ofcontextual associations. If the effect is dueto contextual associations, it is not clear whysubjects in the DC condition do not accessenvironmental information in memory tofacilitate recall of words. Experiments 2 and

3 tested whether DC subjects could over-come environmental context dependence byremembering the room in which learningtook place.

Experiment 1

There is at least one explanation of theenvironmental reinstatement effect that doesnot assume that the mental representationsof context and of verbal material becomeintegrated when the material is learned. Thisexplanation is based on the fact that in thetypical environmental reinstatement para-digm, SC subjects are tested in a familiarroom and DC subjects are tested in novelsurroundings. It may be assumed that sub-jects in a psychology experiment attend totheir environmental surroundings with anx-iety, interest, or suspicion, any of whichwould produce a performance decrement.Such anxiety or interest in the environmentwould be greater in novel surroundings.Therefore, the environmental reinstatementeffect, or a portion of it, could be explainedas a general performance decrement (theperformance hypothesis), rather than aresult of contextual associations (thememory hypothesis).

There is some evidence of contextual asso-ciations that cannot be explained by the per-formance hypothesis. Bilodeau and Schlos-berg (1951) found that retroactive inter-ference (RI) was reduced if original learn-ing (OL) and interpolated learning (IL)occurred in separate rooms, as comparedwith the standard condition where OL andIL occurred in the same room. This resulthas been replicated by Greenspoon andRanyard (1957) and Strand (1970) withhuman subjects, and by Zentall (1970) withrats. The memory hypothesis states that RIwas reduced in the varied context conditionbecause the test context did not match theinterpolated list context. Hence, IL listwords were remembered more poorly, andthere was less interference caused by thosewords. The performance hypothesis does notpredict the reduction of RI because bothgroups were tested in a familiar experi-mental setting.

Strand (1970), however, attributed this

462 STEVEN M. SMITH

result not to contextual associations butinstead maintained that the physical disrup-tion involved in changing contexts betweenOL and IL was responsible for the reducedinterference effects. She found that merephysical disruption between lists reducedRI as much as an actual change of context.This finding, she explained, was a result ofincreased list discrimination caused by adisruption between lists, whether or not thedisruption also involved a room change.

With Strand's (1970) disruption hypoth-esis to explain reduced interference effectsand the performance hypothesis as an expla-nation of the typical environmental reinstate-ment effect, there remains only one experi-ment whose results require the memoryhypothesis. In Experiment 2 of the study bySmith et al. (1978), subjects studied twolists of words in two different contexts andwere tested in one of these two contexts.Smith et al. found that words were remem-bered best when tested in the room in whichthat list was studied. Neither the disruptionhypothesis (all subjects were equally dis-rupted) nor the performance hypothesis (allsubjects were in the test room prior to test-ing) can explain this result.

Even though Smith et al.'s results supportthe memory hypothesis, it is still not certainwhether the typical environmental reinstate-ment effect is caused solely by contextualassociations. It is possible that a substantialproportion of the effect is caused by theunfamiliarity of the test context (the per-formance hypothesis), even if there is somecontextual cuing involved in that situation.Experiment 1 was designed to evaluate theperformance hypothesis as a possible expla-nation of the environmental reinstatementeffect.

Two variables, context matching and con-text familiarity, have been confounded inthe typical context reinstatement paradigm.The memory hypothesis states that contextmatching is solely responsible for the en-vironmental reinstatement effect; that is,when the learning and test contexts match(SC condition), a subject can use associa-tions in memory that link that context andthe material learned, whereas a mismatch

(DC condition) does not make such associa-tions available. The performance hypothesisstates that context familiarity produces thereinstatement effect; the unfamiliar sur-roundings of the DC condition disrupt thosesubjects' performance relative to the SCsubjects, who are tested in a familiarenvironment.

The test of these two hypotheses requiresa design that separates the variables of con-text matching and familiarity. Subjectsstudied a list of words in one room (RoomA) and then moved to a second room(Room B or C). They were familiarized withthe second room by drawing sketches of theroom and its contents. Subjects were sub-sequently given a test for free recall of listwords in the room in which they studied thewords (Group ABA), the room that wasfamiliar but in which no words were pre-sented (Group ABB), or in a new environ-ment (Group ACB). If the memory hypoth-esis is true, then Group ABA should recallmore words than Groups ABB and ACBbecause the input and test rooms matchedonly for Group ABA. If the performancehypothesis is true, then Groups ABA andABB should recall equal amounts, sincethey were both tested in familiar environ-ments, and both should recall more thanGroup ACB, which was tested in an un-familiar room. If both matching and famil-iarity affect recall, then Group ABA shouldrecall the most words (benefiting from bothmatching and familiarity), Group ABB thenext most (tested in familiar, but mis-matched room), and Group ACB the fewestwords (tested in the unfamiliar, mismatchedroom).

Method

Subjects. Thirty introductory psychology stu-dents served in the experiment. Each was givencourse credit points following participation.

Procedure. Subjects participated either singlyor in pairs for one 30-min. session. The session wasdivided into three 10-min. sections, and each sectionwas followed by a brief return to the subject wait-ing room.

The first 10-min. section consisted of list learning,followed by a partial recognition test. Subjectswere instructed to memorize list words in any waypossible without worrying about the word order.

REMEMBERING IN AND OUT OF CONTEXT 463

Individual words were presented at 3-sec intervals(on slides in Room B or on a tape recording inRoom A). Subjects were then given a recognitiontest over 10 (old) list words and 10 (new) dis-tractors. Subjects responded on a 6-point con-fidence rating scale; 1-3 indicated an "old"response, with 1 indicating complete confidence,and 4-6 indicated a "new" response, with 6 indi-cating complete confidence. Test words wereshown for 6 sec apiece. The partial recognitiontest was used for closure so that subjects, who werenot informed about a later free recall test, wouldnot actively rehearse list words after the list-learning task.

The second 10-min. session was a context famil-iarization task. Subjects were told that this partof the experiment concerned depth perception.They were instructed to draw two different viewsof the room they were in without labeling any partof their sketches. Five minutes were allowed foreach sketch. Subjects were instructed to omit theother person(s) in the room (i.e., the experi-menter and the other subject, when there wasone) from their sketches. It seemed that this taskwould make the ABB subjects at least as familiarwith the free recall test room as ABA subjects.

Following the context familiarization task, sub-jects returned to a waiting room for 3 min. (toensure equal disruption for all groups). They werethen taken to the test room corresponding to theirexperimental group and were told to write, for 10min., all of the list words and test words theycould remember, and to guess if necessary.

Design. Three rooms, A, B, and C, were used.Ten subjects were randomly assigned to each ofthe three groups, which differed only in the pat-tern of rooms used for the various tasks. For onecounterbalancing, subjects in Group ABA had listlearning in Room A, context familiarization inRoom B, and free recall testing in Room A. GroupABB had A first, then B, and then B, and GroupACB had A first, then C, and then B. For thesecond counterbalancing, Rooms A and B werereversed, giving the corresponding Groups BAB,BAA, and BCA. The combined subgroups of ABAand BAB are referred to as Group ABA, ABBand BAA as Group ABB, and ACB and BCA asGroup ACB.

List learning always occurred in the first contextto avoid the possibility of an unequal influence ofcontext familiarity on the learning (as opposed toremembering) of the three groups. The familiar-ization task occurred second so that the room thatwas familiar (but did not match the list inputroom) would be more recent at the time of thetest and would, therefore, be at least as familiar tothe subject as the list-learning room.

Materials and apparatus. List words and testwords were one syllable, four- and five-letter,unrelated, high-frequency English nouns drawnfrom the Kucera and Francis (1967) norms. Onlywords of frequency SO or more per million were

chosen. There were 80 words presented on the listand 10 new distractors on the recognition test(which also contained 10 old list words), makinga total of 90 possible words to be recalled.

For context B, words were typed in capitalletters on slides, projected onto a wall via aCarousel projector, and changed by an electronictimer. For Context A, words were read aloud overa cassette tape recorder.

Environmental contexts. Room A was on thefifth floor of the psychology building near theanimal laboratories. Subjects sat in a crowded sound-proof booth inside a room filled with computerequipment, and words were presented via a taperecorder. Room B was a larger room in the base-ment of the building. There was a huge orangedrapery hanging from the ceiling, posters and pic-tures on the walls, plastic plants, carpeting, a sink,books, a table, and chairs. Room C was a fairlyempty room on the second floor of the building,containing desk chairs, a slide projector (not used),a viewing screen, a wastebasket, and a cabinet. Thethree rooms were in different locations, and theylooked very different from one another.

Results and Discussion l

Averaged across counterbalancings, themean recall scores were 24.0 words forGroup ABA, 18.5 words for Group ABB,and 17.7 words for Group ACB. An analysisof variance (ANOVA) comparing the threegroups did not show significant differencesamong the means, F(2, 27) = 3.17, MSe= 37.13.

Orthogonal contrasts show superiority ofrecall of Group ABA over the other twogroups, F(l, 27) = 5.78, accounting for98.6% of the treatment sum of squares. Theremaining orthogonal comparison of GroupABB vs. ACB was not significant, F(l, 27)= .08.

The results support the memory hypoth-esis, since the same-context group (ABA)recalled more words than either of the differ-ent-context groups (ABB and ACB).There was no effect of the context famil-iarity variable. It is concluded, therefore,that the memory hypothesis remains themost parsimonious explanation of knownenvironmental reinstatement effects.

1 The level of alpha was set at .OS for the analy-ses in all experiments.

464 STEVEN M. SMITH

Experiment 2

To reiterate, contextual associations refernot to the actual physical stimuli, but ratherto the mental representations of the environ-mental context and of the list words. Theenvironmental reinstatement principle im-plies that the SC environment elicits re-trieval of the representation of that contextthat was stored at input, and this processprovides access to contextual associations.Subjects in the DC condition do not retrievea representation of the environment, andtherefore cannot access and use contextualassociations to help recall of words. Experi-ments 2 and 3 examined the reason(s) thatDC subjects do not retrieve and use thestored representation of the learning en-vironment as a means of facilitating wordrecall.

Remembering the context as a means offacilitating memory of events that occurredin that context is a mnemonic techniquewhose usefulness has been pointed out bywell-known mnemonists. Simonides (citedin Bower, 1970) remembered the occupantsof a room by first recalling the various locithat existed in the room, and Luria's (1968)mnemonist, S., memorized and recalled listsof objects with the use of imagined placesalong a street in Leningrad. In these ex-amples, it was not necessary for the subjectto be placed in the physical surroundingswhose mental representation was linked withthe sought-for information. The context wasreinstated not perceptually but mnemon-ically; its representation was retrieved frommemory without the physical presence ofthat context to serve as a stimulus.

It is clear that there are situations inwhich a subject makes use of retrievedinformation in memory when the physicalcounterpart of that retrieved information isnot present. For example, a subject whorecalls a categorized list of words does notalways need to have the category nameprinted out to make use of category-list wordassociations; the subject need only recallthe category name from memory to accessthose associations. A study by Petersen andJacob (1978) has pointed out the impor-tance of memory for context when the

subject is recalling noun tetrads, when thecontext was a word that thematically con-nected the four words of the tetrad. Theyfound that the primary factor determiningrecall of the tetrads was the recall ofcontexts.

The purpose of this discussion is to pointout the possibility that DC subjects in theenvironmental reinstatement paradigm mightbe able to access contextual associations byrecalling aspects of the environmental con-text from memory. If such a technique ispossible, why do DC subjects apparentlynot use it ? Two hypotheses, the cuinghypothesis and the strategy hypothesis, areproposed as answers to this question.

The cuing hypothesis relates recall per-formance to one's ability to recall the inputenvironmental context. It states simply thata representation of the subject's inputenvironment is cued by the physical rein-statement of that context, thus makingcontextual associations easily available.When that environment is not physicallypresent (i.e., DC subjects), it is more diffi-cult for the subject to remember the list-learning context, and contextual associationsare not as accessible.

The strategy hypothesis states that themechanism that underlies the environmentalreinstatement effect involves not the sub-ject's ability to remember the input environ-ment, but rather the likelihood that a subjectwill use the strategy of remembering theinput room to facilitate recall of list words.According to this hypothesis, both SC andDC subjects are equally able to rememberthe environment in which list learning tookplace, but SC subjects are more likely thanDC subjects to adopt this strategy. Thestrategy hypothesis predicts, then, thatmerely instructing the DC subjects to usethis strategy should eliminate the recalldifference between SC and DC groups.

A combination of the strategy and cuinghypotheses is also possible. This combinationstates that DC subjects are less likely thanSC subjects to use context recall as astrategy for facilitating word recall, andfurther, when such a strategy is used, SCsubjects are better able to recall their inputenvironment than DC subjects.

REMEMBERING IN AND OUT OF CONTEXT 465

To test these hypotheses, three conditionswere added to the traditional same- anddifferent-context conditions (see Table 1).In these three treatments, subjects in a dif-ferent context were given special instruc-tions just prior to a free recall task forlist words. The different-context-remember(DC-R) group was simply instructed to tryto remember their input room and to tryto use that memory to help recall list words.The different-context-cued (DC-C) groupwas given the same context-recall instructiongiven the DC-R group, except that the DC-C subjects were also allowed to view photo-graphs of their input room to facilitate theirmemory of that environment. Finally, thedifferent-context-placebo (DC-P) groupwas given a placebo instruction to recall anirrelevant environment to determine theeffect of a context-recall instruction whensuch an instruction was unlikely to give thesubject access to appropriate contextualassociations.

The strategy hypothesis predicts thatGroups DC-R and DC-C (both of whichwere told to use the context-recall strategy)will recall more words than the DC group,and that performance of Groups DC-R andDC-C will be equal to that of the SC group.The cuing hypothesis predicts that GroupDC-C will recall more than Groups DC,DC-R, and DC-P, since DC-C is givenretrieval cues (photographs) to facilitatememory for the input environment andGroups DC, DC-R, and DC-P are not. Acombination of the two hypotheses predictsthat Group DC-C will recall more wordsthan Group DC-R, which will recall morethan Group DC.

All hypotheses predict that Group SC willrecall more than Group DC, and nonepredict that Groups DC and DC-P willdiffer in recall.

Method

Subjects. Fifty introductory psychology stu-dents at the University of Wisconsin—Madisonserved as subjects. Each was paid course creditpoints at the end of the two 30-min. sessions.

Materials, apparatus, and contexts. The ma-terials and apparatus were identical to those de-scribed for the list-learning session of Experiment1. The environmental contexts used were described

as Room A and Room B in the Method sectionof Experiment 1. List words were presented ona tape recording at 3-sec intervals in all conditions.

The IS slides shown to Group DC-C prior toword recall were projected onto the screen inRoom A via a Carousel projector. The slides werepictures of the subject waiting room, the corridorsand stairway on the way to the experimental room(Room B), and numerous photographs of theinside of the room.

Design and procedure. On the first day, allsubjects were brought to Room B and were takenthrough the list-learning and partial recognitiontesting procedures described in the Method sectionof Experiment 1. The 10 subjects randomlyassigned to each group differed from the othergroups according to their experimental treatmentimmediately prior to the surprise free recall teston the second day. Subjects in Group SC returnedon the second day to the room in which list learningtook place (Room B) and were given 10 min.to write, in any order, all of the list words andtest words that they could remember from theprevious day.

All other groups were tested in Room A on thesecond day. Group DC differed from Group SConly in that Group DC was tested in Room A, andGroup SC was tested in Room B, the list-learningroom. Subjects in Group DC-R were first askedto write down the location of their list-learningroom, and to list any 10 things they could remem-ber seeing in that room (if they could rememberthat many). Three minutes were given for thistask. Subjects were then asked to take 2 min. tothink about Room B, what it looked like, whatsounds and smells were there, where it was, andthe way it made them feel. They were then toldthat the context-recall task they had been doingmight help them recall words that were presentedin that room, and they were asked to try to usetheir memory for Room B to help them to recallthe list and test words from the previous day. Tenminutes were given for the free recall test.

Group DC-C was tested exactly like GroupDCrR, except that during the 2 min. context-recalltask, subjects were shown slides of the experi-mental room to help them remember as muchabout Room B as possible.

Group DC-P was treated the same as GroupDC-R except that instead of remembering infor-mation about Room B, they recalled informationabout a room at home (e.g., living room or dormi-tory room). These subjects were told that theexercise was a good "mental warm-up" for remem-bering other sorts of information, and that itmigh help them to recall the words from theexperiment.

Results and Discussion

The group means are shown in Table 1.Groups SC, DC-C, and DC-R all recalled

466 STEVEN M. SMITH

Table 1Day 2 Instructions and Mean Word Recall forFive Experimental Groups: Experiment 2

MGroup Instructions prior to free recall recall

SC None 18.0DC-C Recall Room B, view photos of

Room B 18.8DC-R Recall Room B, think about Room B 17.2DC None 12.0DC-P Recall room at home, think about

room at home 9.6

Note. SC = same context, DC-C = different con-text-cued, DC—R = different context-remember, DC= different context, DC—P = different context-placebo instruction.

more than Groups DC and DC-P. AnANOVA comparing the mean free recall scoresfor the five groups showed a significant dif-ference among the means, F(4, 45) = 5.13,MSe = 32.35. Pairwise comparisons, usingthe least significant difference method (LSD= 5.13) indicated that the means of SC,DC-C, and DC-R did not differ from eachother, and that all three recalled more wordsthan DC and DC-P, which did not differfrom each other.

The results offer strong support for thestrategy hypothesis. The robust environ-mental reinstatement effect (Group SCrecalled one and a half times the number ofwords recalled by Group DC) was elim-inated merely by giving DC-R subjects aninstruction to use their memory for theirinput environment to facilitate word recall.Word recall was not facilitated merely byan instruction to recall information aboutany environment; DC-P subjects performed,if anything, worse than DC subjects on thefree recall test. Facilitation occurred onlywhen the recalled environmental informa-tion was specific to the list-learning episode.

One possible criticism of Experiment 2 isthat the DC-C and DC-R groups may haveimplicitly retrieved list words during thecontext recall that preceded the word recalltask. This could have increased the wordrecall of those subjects, since longer recallintervals and multiple recall sessions have

been known to yield better word recall scores(Erdelyi & Kleinbard, 1978).

This criticism, however, is mitigated bythe following: First, the subjects had littlereason to believe that they would be testedfor memory of list words on the second day.They had already been tested on the listwords on the first day, and the context recallinstruction specified only that they recallobjects in the room. Second, the 10-min.free recall interval was more than enoughfor subjects to exhaust their memory forlist words; there were no subjects stillwriting responses at the end of the 10 min.Finally, at the very worst, such a criticismwould necessarily support the idea of con-textual associations, since the DC-P groupobviously did not benefit from this poten-tially longer test interval.

The conclusion drawn from the presentset of results was that contextual associa-tions in memory can be accessed whetherelicited perceptually or mnemonically; thephysical presence of the context is notnecessarily needed for its reinstatement tooccur. This implies that DC subjects recallless than SC subjects in the typical environ-mental reinstatement paradigm because DCsubjects do not employ the mnemonic strat-egy of using memory for environmentalcontext to help recall list words. Wheninstructed to use this mnemonic strategy,DC subjects are able to successfully employit.

The cuing hypothesis was not supportedby the results. Group DC-C viewed photo^-graphs of their list-learning room, and SCsubjects were returned to their input room.These two groups, therefore, were providedwith more environmental information thanDC-R. According to the cuing hypothesis,DC-R should have recalled fewer wordsthan SC or DC-C because those subjectswere given less contextual information. Theresults, however, did not support this pre-diction, as the recall scores of SC, DC-C,and DC-R did not differ from one another.

Experiment 3

The fact that no recall differences werefound between SC, DC-C, and DC-R in

REMEMBERING IN AND OUT OF CONTEXT 467

Experiment 2 suggests that the cuinghypothesis should be rejected. It may be,however, that the design of Experiment 2did not produce a situation in which SC andDC subjects were differentially able to recalltheir input environmental context. It is notclear how well a DC subject must be ableto recall the input environment to producethe release from contextual dependenceevidenced in Experiment 2. It may be thatonly a small amount of environmental infor-mation must be recalled for the subject togain access to contextual associations. Or,the situation in Experiment 2 may havemade contextual information very easy torecall, such that SC, DC-C, and DC-Rwere all able to derive the maximal benefitfrom the use of their memory of the list-learning room as a retrieval aid.

It seems reasonable that memory for con-textual information should be constrainedby the same or similar rules that governmemory for other types of information. Forexample, memory for context should im-prove with increased exposure to that con-text, and context should be forgotten whenthe retention interval or the number ofcompeting responses (i.e., related contexts)increases.

Experiment 3 was designed to manipulatethe subject's ability to remember the learn-ing context by varying the number of com-peting contextual responses. Subjects werepresented with either many (four) or few(one) distractor rooms on the same day aslist learning. (See Table 2 for design androom assignments.) It was expected thatmemory of these rooms would serve ascompeting responses for the subject'smemory of the list-learning room and,therefore, that subjects would be better ableto remember one of two environments thanone of five.

In this experiment those tested in the DCconditions were asked to remember informa-tion about their list-learning room to helpthem remember list words. This instructionwas used to avoid strategic differencesbetween the groups, so that any differencesin free recall performance would reflectdifferences in the subjects' abilities to accessenvironmental information.

Table 2Room Assignments of Experimental Groupsfor the Experimental Tasks: Experiment 3

Group

Task

Multiplicationproblems

List learningSignal

detectionLetter

rotationVisual search

Free recall

SC-2 SC-S

First day

AB

A

AA

Second day

B

AB

C

DE

B

DC-2

AB

A

AA

F

DC-S

AB

C

DE

F

Note. SC-2 = same context-two rooms, SC-S = samecontext-five rooms, DC-2 = different context-tworooms, DC-5 = different context-five rooms.

The predictions made by the cuing hy-pothesis are illustrated in the hypotheticalrepresentations and search schemes shownin Figure 1. The hierarchical structureshows the representations of environmentalcontext from the first day subsumed by amore general node labeled experiment. Listwords are subsumed by, or associated onlywith, Room B. Same-context subjects,whether having had two or five rooms on thefirst day (SC-2 and SC-S), should be cuedto access appropriate environmental infor-mation (i.e., Room B) by the physical rein-statement of that context. These two groups,then, should not differ in the amount of en-vironmental information that is accessibleand, therefore, should not differ in free re-call performance. The two DC groupSj how-ever, must recall the appropriate environ-mental information from memory. Assum-ing a top-down search beginning with theexperiment node, DC subjects with tworooms (DC-2) are better able to retrieveRoom B information than those with fiverooms (DC-S) because DC-5 should be lessable to differentiate memory of Room Bfrom memory of the distractor rooms. There-fore, the cuing hypothesis predicts poorerword recall for DC-5 than for DC-2, which

468 STEVEN M. SMITH

TWO INPUT ROOMS FIVE INPUT ROOMS

Figure 1, Hypothetical memory search schemes for four groups in Experiment 3. (Groups SC-2and SC-5 can easily access context-list word associations. Group DC-2 needs only to rememberone of two Day 1 rooms to access contextual associations. Group DC-S, however, mustdiscriminate among five Day 1 rooms to recover and use context-list word associations.)

should recall nearly as much as SC-2 andSC-5.

The strategy hypothesis, which is notrelevant to the subject's ability to recall in-formation about an environment, predictsequal free recall performance for all groups,since all supposedly are using memory forRoom B to help recall of words.

Method

Subjects. Forty inroductory psychology stu-dents received course credit points following theirparticipation in the 2-day experiment. Subjectsparticipated either singly or in pairs.

Design, procedure, and materials. The generaldesign of Experiment 3 is outlined in Table 2.On the first day, subjects were given a series offive tasks, each of which lasted approximately 10min. One of the tasks (the second of the five)was the list-learning procedure described in Ex-periment 1. The other four were dummy tasksdesigned to be noninterfering with verbal mem-ory, and these took place in either one room orfour rooms. For all groups, list learning was theonly task to occur in Room B.

On the second day, subjects were given a freerecall test for the words learned in Room B on thefirst day. Half of the subjects were tested inRoom B, and half were tested in a new room. Thefour groups, then, represent same and differentcontext with either two or five rooms presented onDay 1: SC-2 (same context, two rooms on thefirst day), SC-5 (same context, five rooms), DC-2(different context, two rooms), and DC-5 (differ-ent context, five rooms).

Task 1: Multiplication problems. The multi-plication task occurred in Room A (described as"Room C" in Experiment 1). Subjects wrote theanswers to simple multiplication problems, whichwere shown individually on the screen at 2-sec in-tervals. Three sets of 60 problems were projectedvia a Carousel slide projector and were changed

by an electric timer. The problems were of theform, P X Q — ?, where P and Q were one-digitnumbers.

Task 2: List learning and recognition test.List learning and a partial recognition test forsome of the list words occurred in Room B asthe second task of the first day. The room andprocedure are described in Experiment 1, with theexception that words were presented via cassettetape instead of being shown on slides.

Task 3: Auditory vigilance. The auditory vigi-lance task occurred in Room A for SC-2 andDC-2, and in Room C for SC-S and DC-S. (RoomC is described as "Room A" in Experiment 1.)Faint tones were played over a background ofwhite noise on a cassette recorder. During three2-min. intervals, subjects kept a tally of the num-ber of tones heard.

Task 4: Letter rotation. The letter rotationtask occurred in Room A for SC-2 and DC-2, andin Room D for SC-5 and DC-S. Room D was acramped and cluttered room on the fourth floorof the psychology building. Subjects were seatedat two small tables in a room otherwise crammedwith books, papers, and tape-recording equipment.

For this task, pairs of letters were arranged incolumns on a page. The left-hand member of eachpair was printed in its normal reading orientation.The right-hand member was printed at one offour angles from vertical (45°, 135°, 225°, and315°) and was half of the time forward and halfof the time reversed in mirror image of the for-ward letter. The letters F, G, J, P, R, and S wereprinted in capital block form. The subject's taskwas to mentally rotate the right-hand letter ofeach pair to see if it matched the letter on the left.

Subjects were given eight columns with 12letter pairs per column and were allowed 10 sec toevaluate the letters of each pair as "same" or "dif-ferent" with 30-sec breaks given between columns.

Task 5: Visual search. The visual search taskoccurred in Room A for SC-2 and DC-2, and inRoom E for SC-S and DC-5. Room E was asmall, uncluttered room on the fourth floor of thepsychology building. Beside the table at which

REMEMBERING IN AND OUT OF CONTEXT 469

subjects sat, the room contained a soundproofbooth,, cabinets, and miscellaneous electronic labequipment.

Subjects scanned columns of letter strings,searching for and circling exemplars of the targetletter N. Twelve seconds was given for each col-umn, with 30-sec breaks between columns. Thetarget letter N was randomly embedded in letterstrings, made up from the letters B, D, G, S, C,and R. Each letter string contained six letters.There were 36 letter strings per column, and therewere 10 columns of letter strings per subject.

Day 2: Free recall. On the second day, sub-jects were taken either to Room B (SC-2 andSC-S), or to a new room, Room F (DC-2 andDC-S). Room F was a very large room on thesecond floor of the psychology building. It con-tained four long tables with chairs, and along aback wall were boxes of equipment, file drawers,and storage cabinets.

Subjects were asked to write, for 10-min., allof the list words and test words they could re-member that were presented on Day 1 in Room B,guessing if necessary.

Prior to the free recall test, subjects in DC-2and DC-S were asked to remember informationabout Room B and to try to use that rememberedinformation to help recall list and test words.They were initially given 3-min. to write the lo-cation of the list-learning room, and they wereasked to list any two things that they could re-member seeing in that room. All subjects got atleast two of these three items of information(location plus two objects) correct in this initialcontext recall exercise. Subjects were then askedto take 2-min. of silence to try to mentally re-create the sights, sounds, and general impressionsof the list-learning room. Following this, subjectswere given free recall instructions, and they wereasked to try to use their memory of the list-learn-ing room to help their memory of the list and testwords. These context recall instructions were in-cluded to ensure that all subjects would be likelyto use environmental information as a strategyto aid word recall. Differences in word recall thatremained should not reflect strategic differences,they should reflect differences in ability to recallenvironmental information.

After the free recall test, DC subjects weregiven a context recall test and a context recog-nition test. For context recall, they were givenS-min. to list all of the things they could remem-ber seeing in the list-learning room. Context re-call was scored as the number of items recalledfrom a comprehensive checklist of items containedin Room B. The three items of information listedon the initial 3-min context recall were includedin this recall score.

For the context recognition test, subjects judgedwhether photographic slides were pictures of thelist-learning room. Fourteen of the photos were"old," that is, pictures of objects in Room B that

20

10

ONE ROOM

TWO ROOMS

,FIVE ROOMS

ISAME

TEST CONTEXTDIFFERENT

Figure 2. Mean free recall scores for Experiments2 and 3 comparing SC- vs. DC-instructed groupswith varying numbers of Day 1 rooms. (Trianglesindicate results for Groups SC-S vs. DC-S in Ex-periment 3, squares show Groups SC-2 vs. DC-2in Experiment 3, and circles compare Group SCwith the combined mean of Groups DC-R andDC-C in Experiment 2.)

had been clearly visible. These were photos, forexample, of posters, plastic plants, a sink, a book-case, or the table at which the subject set. Theother 14 photos were taken in psychology depart-ment rooms in which the subjects had not been,showing objects such as a fire extinguisher, aclock, a bulletin board, or pieces of laboratoryequipment. The 28 test slides were paced at a rateof 10 sec apiece.

Results and Discussion

The mean free recall scores for words areshown in Figure 2. As predicted by the cu-ing hypothesis, the reinstatement effect oc-curred only for the five-room condition,where memory for environmental informa-tion supposedly suffered from more interfer-ence than in the two-room condition. Alsoincluded in Figure 2 are the results ofGroups DC-R and DC-C versus Group SCfrom Experiment 2. Although these datawere not included in the analysis of Experi-ment 3, their inclusion in Figure 2 helps il-lustrate the increase in the size of the en-vironmental reinstatement effect that occurs

470 STEVEN M. SMITH

when more interfering distractor rooms areadded to the Day 1 session.

A 2 X 2 (Context X Number of Rooms)ANOVA computed from the word recall scoresshowed a significant effect only for numberof rooms, F(l, 36) = 4.25, MSK = 50.93.Planned orthogonal comparisons, however,bear out the primary predictions moreclearly.

Memory for Context B, the list-learningroom, should have been most severely im-paired for DC—5, which had to recall one offive possible rooms from the first day toaccess appropriate contextual information.Group DC-5 recalled significantly fewerwords than the other three groups, F(l, 36)= 6.35, accounting for 91% of the totaltreatment sum of squares.

As noted in Figure 1, both SC groupsshould have had equal access to appropri-ate environmental information at the timeof the test; hence, recall performance ofSC-2 should not differ from that of SC-5.The SC groups did not differ, F(l, 36) =.66.

Group DC-2 should have had access tonearly as much environmental informationas the two SC groups, since that group hadonly one distractor room on the first day tointerfere with memory for EnvironmentalContext B. There was no difference in re-call performance between Group DC-2 andthe SC groups, F(l, 36) = .01.

The strategy hypothesis predicted thatword recall for all groups would be equal;because they were instructed, all groups werelikely to use the context recall strategy tohelp word recall. Although the strategy hy-pothesis explains the findings of Experiment2, it cannot account for the poorer free re-call performance of DC-5 in Experiment 3.Given the combined results of Experiments2 and 3, it appears that the typical environ-mental reinstatement effect can occur be-cause the SC subject is more likely thanthe DC subject to use remembered environ-mental information to help word recall,and/or because such environmental informa-tion may be easier for the SC subject toaccess from memory.

The context recall and context recognitiontasks were not particularly sensitive to the

assumed difference of context accessibilitybetween DC-2 and DC-5, although the smalldifference that was found was in the pre-dicted direction. Group DC-2 recalled anaverage of 8.2 objects, as compared with 7.0for Group DC-5. This difference was notsignificant, t(l8) = 1-50. For the contextrecognition test, d' scores were calculated asa measure of the subject's ability to dis-criminate photographs of objects in the list-learning room from photos of objects notseen by the subject during the experiment.The mean d' for DC-2 was 1.13, as comparedwith .97 for DC-5. This difference was notsignificant, t(18) = .69.

These results suggest that some aspect ofenvironmental context other than the ob-jects in the room becomes associated withlist words in a list-learning experiment. Itis also possible, however, that the contextmemory tests were contaminated by the priorfree recall test; perhaps list informationacted as a retrieval context that facilitatedlater memory for environmental information.

General Discussion

The present experiments provide evi-dence that the environmental reinstatementeffect is not caused by an experimental arti-fact. They also show that activation of con-textual associations can be achieved byphysically reinstating the appropriate en-vironmental context or mnemonically byinstructing subjects to remember their list-learning environment. Mnemonic activationof contextual associations was shown to bean effective retrieval aid only when the en-vironmental context was not difficult toremember.

The results have strong implications forboth theory and application. First, they dem-onstrate that environmental context infor-mation is, as formerly believed, a source ofretrieval cues useful for recalling informa-tion learned in that context. The results fur-ther imply that memory depends on physicalcontextual cues because subjects are notaware that information already in memorycan be used as a retrieval aid. When in-structed, subjects can bring context effectsat least partially under cognitive control by

REMEMBERING IN AND OUT OF CONTEXT 471

generating their own retrieval cues frommemory. Finally, the results show that mem-ory for context is constrained by factorssimilar to those that affect memory of verbalmaterial. The addition of several distractorrooms interfered with memory for a particu-lar room, reducing the effectiveness of self-generated contextual cues.

The results are empirically important be-cause they show a means for eliminating orenhancing the environmental reinstatementeffect. The effect can be wiped out by simplyinstructing DC subjects to remember theirlearning environment if that environmentis easy to remember, or it can be enhancedif the learning environment is made moredifficult to remember. These methods areimportant considerations for practical ap-plications, as well as for further laboratoryinvestigations of environmental contexteffects.

References

Anderson, J. R., & Bower, G. H. A prepositionaltheory of recognition memory. Memory &• Cog-nition, 1974, 2, 406-412.

Bilodeau, I. M., & Schlosberg, H. Similarity instimulating conditions as a variable in retro-active inhibition. Journal of Experimental Psy-chology, 1951, 41, 199-204.

Bower, G. H. Analysis of a mnemonic device.American Scientist, 1970, 58, 496-510.

Carr, H. A. Psychology: A study of mental ac-tivity. New York: Longmans Green, 1925.

Eich, J. E., Weingartner, H., Stillman, R. C., &Gillin, J. C. State-dependent accessibility of re-trieval cues in the retention of a categorized list.Journal of Verbal Learning and Verbal Be-havior, 1975,14, 408-417.

Erdelyi, M. H., & Kleinbard, J. Has Ebbinghausdecayed over time?: The growth of recall (hy-permnesia) over days. Journal of ExperimentalPsychology: Human Learning and Memory,1978, 4, 275-289.

Farnsworth, P. R. Examinations in familiar andunfamiliar surroundings. Journal of Social Psy-chology, 1934, 5, 128-129.

Godden, D. R., & Baddeley, A. D. Context-de-pendent memory in two natural environments:On land and underwater. British Journal ofPsychology, 1975, 66, 325-331.

Greenspoon, J., & Ranyard, R. Stimulus condi-tions and retroactive inhibition. Journal of Ex-perimental Psychology, 1957, 53, 55-59.

Kintsch, W. The representation of meaning inmemory. Hillsdale, NJ.: Erlbaum, 1974.

Kucera, H., & Francis, W. N. Computationalanalysis of present-day American English. Provi-dence, R. I.: Brown University Press, 1967.

Light, L. L., & Carter-Sobell, L. Effects of changedsemantic context on recognition memory. Journalof Verbal Learning and verbal memory, 1970, 9,1-11.

Luria, A. R. The mind of a mnemonist: A littlebook about a I'ast memory. New York: BasicBooks, 1968.

McGeoch, J. A. The psychology of human learning:An introduction. New York: Longmans Green,1942.

Petersen, R. C., & Jacob, S. H. Evidence for therole of contexts in imagery and recall. Ameri-can Journal of Psychology. 1978, 91, 305-311.

Santa, J. L., & Lamwers, L. L. Encoding speci-ficity : Fact or artifact ? Journal of Verbal Learn-ing and Verbal Behavior, 1974, 13, 412-423.

Smith, S. M., Glenberg, A. M., & Bjork, R. A.Environmental context and human memory.Memory & Cognition, 1978, 6, 342-353.

Stillman, R. C., Weingartner, H., Wyatt, R. J.,Gillin, J. C, & Eich, J. E. State-dependent(dissociative) effects of marijuana on humanmemory. Archives of General Psychiatry, 1974,31, 81-85.

Strand, B. Z. Change of context and retroactiveinhibition. Journal of Verbal Learning and Ver-bal Behavior, 1970, 9, 202-206.

Zentall, T. R. Effects of context change on for-getting in rats. Journal of Experimental Psy-chology, 1970, 86, 440-448.

Received November 29, 1978Revision received April 26, 1979 •