False Recall and False Memory:The E�ects of Instructions on Memory Errors

BETH A. NEWSTEAD1 and STEPHEN E. NEWSTEAD2*1St. Hilda's College, Oxford, UK

2University of Plymouth, UK

ABSTRACT

An experiment is reported using a list-learning paradigm in which all the words have acommon associate, which is known to be frequently but erroneously recalled. Four experi-mental conditions were used. One group was instructed to think about the meanings of thewords, another to relate them to personal experience, another to create images of the words,and another to chain the words into a sentence. Both thinking about the meaning and chainingincreased recall of the words actually presented, but in none of the conditions was there anye�ect on false recall. The implications and relevance of these ®ndings to the controversy overfalse memories are discussed. # 1998 John Wiley & Sons, Ltd.

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There is a considerable body of evidence supporting the fallibility of human memory.This ranges in content from anecdotal evidence illustrating the inaccuracy with whichpeople often remember past events and experiences (e.g. Loftus, 1993; Wright, 1993)to laboratory studies in which incorrect memories are evoked in participants whenthey are asked to recall stories and sentences (e.g. Bartlett, 1932; Bransford andFranks, 1971). There is also substantial evidence of people coming to believe in thingsthat have never taken place through the process of suggestion (e.g. Hyman, Husbandand Billings, 1995).

Recently, there has been extensive interest in a laboratory paradigm in which thereis a high rate of inaccurate recall when participants are asked to retrieve lists of words.All list words are associates of a common, non-presented word; for instance, for thecommon word sweet, the list might contain words such as sour, sugar, bitter andhoney. The common associated word is frequently erroneously recalled.

This paradigm was used originally by Deese (1959) and has surprisingly beenalmost completely ignored until its recent resurrection. Deese presented participantsverbally with 36 lists of words, each of which consisted of the 12 strongest associatesof the non-presented target word. After each list, participants were immediately asked

CCC 0888±4080/98/010067±13 $17.50 Received 23 January 1997# 1998 John Wiley & Sons, Ltd. Accepted 19 May 1997

APPLIED COGNITIVE PSYCHOLOGY, VOL. 12, 67±79 (1998)

*Correspondence to: Professor S. E. Newstead, Department of Psychology, University of Plymouth,Drake Circus, Plymouth, Devon PL4 8AA.

The ®rst author is now at the Royal Free Hospital, London. The authors gratefully acknowledge the helpand advice of Professor Nick Chater and the assistance sta� and students from Ivybridge CommunityCollege, Devon.

to recall orally the words that they had been presented with. Deese found that thetarget word was recalled by up to 44% of the participants. The probability of falserecall was related to the mean association value of the words on the list, i.e. howstrongly, on average, the words composing the list were associated with the commonword.

This ®nding was taken as a starting point for two studies, in whichDeese's best list(s)were selected, and used in attempts to reproduce and extend his original ®ndings. BothRoediger andMcDermott (1995) andRead (1996) were highly successful in replicatingthis false recall e�ect. Recall of the non-presented target word was found to be as highas 40% by Roediger and McDermott, and 66% by Read, who tested participantsusing a single list. Roediger and McDermott also tested recognition of the presented/non-presented words after the recall test and found a high false recognition e�ect forthe target word. Read showed on a post-recall task that participants were often verycon®dent that the non-presented word had been read out, especially if the target wordwas recalled in an early serial position. Both sets of experimenters found that manyparticipants judged that they could actually remember hearing the target word, asopposed to knowing it had been presented.

More recent studies have shown that the extent of false recall does not decline overa 24-hour period (Payne, Elie, Blackwell and Neuschatz, 1996), that prior testingactually increases the extent of false recall (McDermott, 1996), and that amnesicpatients are less susceptible to the e�ect (Schacter, Verfaellie and Pradere, 1996).Overall, the results from all these studies show a surprisingly high level of erroneousrecall.

Amajor reason why this paradigm has become so popular is that it has been claimedto shed light on the false memory/recovered memory debateÐ the controversy as towhether recovered memories of childhood abuse are genuine memories or are in someway planted during the course of therapy (see, for a review, Lindsay and Read, 1994).False memories can, in this paradigm, be consistently and easily created using materialthat is usually memorized with a high degree of accuracy. The paradigm also has theadvantage of being quickly and easily conducted. It is thus a reasonable starting pointfor study of how false memories might develop. If we can begin to understand howfalse memories might be created under these relatively simple circumstances, then itmight be possible to address the question of whether and how therapy-recoveredmemories are produced.

However, the relevance of this simple experimental technique to the false memory/recovered memory debate has been hotly disputed. Freyd and Gleaves (1996) arguedthat Roediger and McDermott (1995) overemphasized the relevance of this paradigmto the false memory debate, a claim that is refuted by Roediger and McDermott(1996). The di�erences between the list-learning paradigm and a therapeutic sessionare legion and, in the main, transparently obvious. Despite this, the paradigm providesan excellent way of investigating empirically the factors a�ecting false memories, andwill at the very least throw up issues for debate.

Additionally, research using this paradigm can throw light on theories of memory.A number of theories, such as Collins and Loftus's (1975) theory of spreadingactivation, claim that memory nodes are interrelated in complex but predictable ways.Such theories are a�orded support by the existence of false memories in the list-learning paradigm, and the nature of the errors can throw further light on the inter-connections that exist.

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This paradigm allows us to answer questions concerning the factors that encouragefalse memories. It has been claimed for example that false memories are induced intherapeutic situations through the use of hypnosis and other relaxation techniques,through repeated suggestion, through the use of imagery, through writing exercisesand through the presence of an authority ®gure. Some of these factors can be investi-gated using the simple list-learning paradigm, and while ®ndings can never lead to®rm conclusions concerning the e�ects of therapeutic interventions, they can never-theless provide suggestive information.

The present study had a number of aims. The ®rst was to investigate the robustnessof the e�ect: does it occur with participants from a di�erent age group and country?Secondly, we investigated the e�ects of various instructions regarding how toremember the presented words on both overall memory for the list words, and onfalse memory. Four kinds of instructional technique, plus a control condition, wereused.

The ®rst technique was suggested indirectly by the methods that are used intherapy. Memory retrieval can involve guided imagery, in which the therapist guidesthe suspected abuse survivor to create images that may eventually recover a memory(Lindsay and Read, 1994). Actual guided imagery is not possible in an experimentalsituation, but in the present study participants were asked to create images of each ofthe words presented to them. If imagery is a potent factor in false memory, then theseinstructions might lead to an increase in incorrect recall of the target words. Imageryinstructions might also be expected to improve recall of the actual words in the list,since imagery is often a powerful mnemonic device (e.g. Baddeley, 1997).

The second technique was also loosely based on the therapeutic situation. Therapyis obviously a very personal experience whilst learning a list of words is not. In orderto make the experimental situation a little more personally relevant, participants wereasked to relate the words to their personal experiences. Self-referential encoding, inwhich participants judge the personal descriptiveness of presented words, has beenfound to facilitate memory (Rogers, Kuiper and Kirker, 1977). Hence it is possiblethat the present technique, too, might in¯uence recall of the actual words on the list.No speci®c predictions were made as to its e�ect on false memory.

The third type of instructions involved the mnemonic technique of chaining. Thisinvolves linking the presented words together to form a narrative story. When askedto recall the list words, participants can mentally re-run the story they have created inorder to help remember the words. Evidence for the success of this method wasobtained by Bower and Clark (1969) who found that it yielded superior memory bothon longer term recall, and, to a lesser extent, on immediate recall. The technique isclaimed to be most e�ective when participants can pace their own exposure and whenthe words to be remembered are nouns. In the present study, the design necessitatedthat the words be presented at a constant rate. Lists were selected that involved asmany nouns as possible, but other parts of speech were included as well. It wasexpected that chaining would increase recall of the actual words in the list, but nopredictions were made concerning its e�ect on false memories.The fourth experimental condition involved elaboration. Read (1996) found that if

participants were asked to think carefully about the meanings of the list words, thenan increased false memory e�ect was obtained compared to participants who had totry to memorize the words in the exact order that they were presented. Such elabora-tive rehearsal of the words presumably involves deeper processing of the stimulus and

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would be expected to result in improved memory for the presented words (e.g. Craikand Lockhart, 1972). The increase in false memory is attributed by Read to theincreased likelihood of an implicit associative response being made to the target word.One problem with Read's study is that he did not have a control group in whichparticipants were given no special encoding instructions. The present investigationused such a control group, in order to investigate the e�ect more systematically.Following Read, it was predicted that both recall of the original words and of thetarget words would increase in this condition.

To summarize, ®ve experimental groups were used. In the imagery group partici-pants were required to create vivid mental pictures of the words presented to them.Participants in the personal experience group were asked to relate the list words totheir own experiences. A chaining group looked at the e�ect of this mnemonic on bothreal and illusory memories. The elaboration group also involved instructions thoughtto improve memory. Finally there was also a control group, in which participants wereinstructed to remember the list words, but were given no further information how theyshould go about this.

In order to investigate the above questions, some slight modi®cations were requiredto the false memory paradigm reported by Roediger and McDermott (1995) andRead (1996). In order to check whether these changes a�ected the phenomenon, apilot study was conducted.

PILOT EXPERIMENT

The main experiment was modelled closely on those of Roediger and McDermott(1995) and Read (1996). However, some changes were required to their methods,including the selection of lists involving high numbers of nouns, the use of a di�erentage group of participants and a slower presentation rate of words. The purpose of thepilot study was simply to check that the false memory e�ect would occur in thissituation.

Method

ParticipantsTwenty-one secondary school students (average age 15) participated in the pilotstudy.

MaterialsWe used 6 lists of 15 words. All the words in each list were associates of a commonword. The six common words were sleep, sweet, mountain, needle, doctor and chair(see Appendix A). All lists were selected from those used in the Roediger andMcDermott (1995) study. These lists consisted of the ®rst 15 associates of thecommon word, derived from the Russell and Jenkins (1954) word association norms.The six lists were chosen using two major criteria. Firstly, the lists had been shown inthe other studies to produce relatively high levels of erroneous recall of the commontarget word. Secondly, the lists were selected on the basis of their suitability for thesecond part of the experiment. For the second stage of the study it was necessary thatthe words in each list were amenable to certain mnemonic and imaging techniques,

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and this was therefore considered when selecting the lists. In practice, this meant thatlists with large numbers of nouns, especially concrete nouns, were preferred.

ProcedureParticipants were read the following instructions by the experimenter:

`This is a memory test. You will hear 6 lists of 15 words. As each list is beingread you must try to remember all the words on the list. At the end of the list Iwill say ``recall'' and you must then write down all the words you can rememberon the attached piece of paper. You must write down the last few words youheard ®rst and then the rest in any order. You will have two and a half minutesto complete this task.'

The instruction to write down the last few words ®rst was included as a standardinstruction for tests such as this, following Roediger and McDermott (1995).

The words in each list were read at a rate of 1 word/5 seconds. This was a slowerrate of presentation than that used in previous experiments. This modi®cation was inanticipation of the second part of the study, in which participants were to be asked toconsider the list words in particular ways. These additional instructions required extratime for their execution. The lists were presented in the same order to all participants.

Results and discussion

Across all six lists the probability of recall for a word actually contained in the list was0.75. This probability is somewhat higher than that obtained in the Roediger andMcDermott (1995) and Read (1996) studies. This may be due to the slower rate ofword presentation in this experiment, enabling participants to memorize the wordsmore accurately. The probability of recall for the target word was 0.46. This is asimilar ®gure to that obtained by Roediger and McDermott (0.40), and by Read(0.66). In this study, across all 6 lists the target was recalled at a lower rate than any ofthe 15 list words. However, if individual lists are considered, for the sleep, sweet, chairand needle lists (see Appendix A) the probability of target word recall was about thesame as the probability of recall of words in mid-list positions.

Other intrusions did occur during recall, but this was at a very low rate. The proba-bility of recalling any other word in the English language was 0.16. This was signi®-cantly di�erent from target word recall (d.f.� 20, t� 5.7, p5 0.001). Note that this isa highly conservative means of testing the signi®cance of the false memory e�ect sinceit tests the target word against any other intrusion errors. Recall of the target word isthus far greater than would be expected from guessing and random error alone.The data obtained in this study replicate the ®ndings of Roediger and McDermott

(1995), Read (1996) and others. These results con®rm that the false memory e�ectsyielded from this paradigm are robust and will occur with a di�erent participantpopulation and with some changes to the experimental design.

MAIN EXPERIMENT

Method

The aim of this study was to examine di�erences in memory and false memory of listsbetween groups given di�erent types of instructions.

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ParticipantsParticipants were 135 secondary school children aged between 13 and 16 who weretested in groups of varying sizes.

MaterialsIdentical lists to those used in the pilot experiment were used in this study.

ProcedureThe 135 participants were randomly allocated to 1 of the 5 di�erent groups. All ®vegroups were verbally presented with the same core instructions. These were identicalto those used in the pilot experiment except that there was no instruction as to theorder in which the words should be recalled. The reason for this modi®cation was thatsome of the additional instructions given were incompatible with this previousinstruction. Testing was carried out in groups of varying sizes.The ®ve groups were given supplementary written instructions as follows:

Elaboration groupParticipants were asked to think about the meaning of each word as it was

presented to them. They were told to be prepared to answer questions on the wordmeanings at the end of the session, in order to help ensure the instructions werecarried out.

Personal experience groupParticipants were asked to try to relate the words in each list to their own personal

experience. They were told that this might take the form of relating the word to aparticular memory or imagining the word in a situation speci®c to them.

Imagery groupParticipants were requested to try to create a vivid mental image of each word on

the list, or of an image associated in some way with the word. They were told to try torecreate these images when asked to recall the words on the list.

Chaining groupParticipants were asked to try to form a sentence or a story out of the words

presented to them. They were told to place the ®rst list word in a setting that wouldallow other words to be added to it, and then to add subsequent words to the story inthe order in which they were read. At the end of each list, participants were asked togo through the story, and remember the words.

Control groupParticipants were given core instructions only.

List words were presented at the same rate and manner as in the initial experiment.The same amount of time was allowed for recall.

Results

Memory for list wordsOverall, across all experimental conditions and all six lists, the probability of a listword being recalled was 0.72. This was a very similar ®gure to that obtained in the

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pilot experiment. The results are presented in Table 1. An analysis of variance wasused to test for the e�ect of group (control vs. elaboration vs. personal experience vs.imagery vs. chaining) and list on recall. There was a signi®cant di�erence between thelists when analysed over participants [F(5,650)� 5.87, p5 0.001], but not whenanalysed over words [F(5,84)� 0.35, p4 0.1]. There was a signi®cant di�erencebetween groups [F(4,130)� 2.90, p5 0.05 over participants; F(4,336)� 13.45,p5 0.001 over words]. There was no group by list interaction [F(20,650)� 1.52,p� 0.067 over participants; F(20,336)� 1.29, p4 0.1 over words]. Least Signi®cantDi�erence tests (p� 0.05) were employed to compare each of the four experimentalgroups with the control group. Whilst memory was improved in all experimentalconditions, the e�ect only reached signi®cance in the elaboration and chaininggroups.

Memory for non-list wordsThe overall probability of the target word being recalled was 0.38, a slightly lower®gure than in the pilot study. Overall, the critical target word was recalled less oftenthan any of the 15 presented words. However, as in the pilot study, for individual lists,the target word was recalled at approximately the same frequency as words presentedin mid-list positions. The data are presented in Table 2.

The data were analysed using analysis of variance to test for the e�ect of group andlist on recall of the critical target word. The results indicate a signi®cant list e�ect[F(5,650)� 19.35, p5 0.001]. Least Signi®cant Di�erence tests (p� 0.05) showedthat the sleep, needle and sweet lists produced more recall of the target word than didthe doctor, mountain and chair lists, but there were no signi®cant di�erences withinthese triples of words. There was no signi®cant di�erence in target word recallbetween the groups [F(4,130)� 0.25, p4 0.05], nor was there a list by group inter-action [F(20,650)� 0.67, p4 0.5].

The probability of any other non-presented word in the English language beingrecalled was 0.17. A t-test showed that there was a signi®cant di�erence betweentarget word recall and recall of any other non-presented words [t(134)� 10.78,p5 0.001]. As in the pilot study, this result con®rms that the recall of the target wordis signi®cantly higher than would be expected if participants were simply guessing ormaking random mistakes. Only 13% of the subjects failed to recall a single targetword over the six lists.

The non-target words given by participants are of some interest in their own right.The vast majority (approximately 80%) were words that were clear associates of eitherthe target word or one of the words in the lists. Common examples include settee(given in response to the chair list), pain and stitch (given to the needle list), and slope,ice and snow (given to the mountain list). There were a small number of words given(fewer than 5%) that sounded like one of the presented words, for example boat andpill given to the mountain list (mishearings of goat and hill?). The remaining non-target words were not related to the presented words in any obvious way.

A further analysis was carried out to determine whether there was a correlationbetween memory ability and false recall of target words. This was done by correlatingmean number of presented words recalled with mean number of target words given.The correlation was negligible, r�ÿ0.04, p4 0.1. Separate analyses showed thatthis correlation failed to reach signi®cance (p� 0.05) in each of the experimentalconditions.

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Table 1. Mean recall of words contained in lists and standard deviations (in parentheses)

Word list

Group Doctor Sleep Needle Mountain Chair Sweet Mean

Control 0.64 (0.14) 0.65 (0.11) 0.68 (0.14) 0.75 (0.16) 0.68 (0.15) 0.65 (0.17) 0.68 (0.11)Elaboration 0.74 (0.10) 0.72 (0.11) 0.74 (0.14) 0.76 (0.12) 0.77 (0.10) 0.70 (0.17) 0.74 (0.09)Personal 0.69 (0.11) 0.67 (0.08) 0.72 (0.14) 0.74 (0.12) 0.73 (0.16) 0.73 (0.15) 0.71 (0.08)Imagery 0.75 (0.13) 0.66 (0.14) 0.72 (0.12) 0.73 (0.17) 0.72 (0.15) 0.75 (0.15) 0.72 (0.11)Chaining 0.74 (0.14) 0.72 (0.10) 0.77 (0.13) 0.77 (0.15) 0.77 (0.13) 0.81 (0.12) 0.76 (0.09)

Mean 0.71 (0.13) 0.69 (0.11) 0.72 (0.14) 0.75 (0.14) 0.73 (0.14) 0.73 (0.16) 0.72 (0.10)

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Table 2. Mean recall of target words and standard deviations (in parentheses)

Word list

Group Doctor Sleep Needle Mountain Chair Sweet Mean

Control 0.26 (0.45) 0.56 (0.51) 0.59 (0.50) 0.19 (0.40) 0.22 (0.42) 0.59 (0.50) 0.40 (0.24)Elaboration 0.37 (0.49) 0.52 (0.51) 0.41 (0.50) 0.19 (0.40) 0.30 (0.47) 0.37 (0.49) 0.36 (0.21)Personal 0.19 (0.40) 0.52 (0.51) 0.56 (0.51) 0.15 (0.36) 0.30 (0.47) 0.52 (0.51) 0.37 (0.24)Imagery 0.19 (0.40) 0.48 (0.51) 0.56 (0.51) 0.19 (0.40) 0.33 (0.48) 0.44 (0.51) 0.37 (0.25)Chaining 0.22 (0.42) 0.59 (0.50) 0.59 (0.50) 0.15 (0.36) 9.26 (0.45) 9.63 (0.49) 0.41 (0.24)

Mean 0.24 (0.43) 0.53 (0.50) 0.54 (0.50) 0.17 (0.38) 0.28 (0.45) 0.51 (0.50) 0.38 (0.23)

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Discussion

The results of the present experiment clearly indicate the robust nature of falsememory production in this list-learning paradigm. Across all experimental groupsand all lists, participants recalled the critical non-presented word 38% of the time.Although this is a slightly lower ®gure than that obtained in previous studies, it is stillsigni®cantly higher than recall of other non-presented words. Furthermore, for somelists, recall of the target word was equivalent to recall of words in mid-list positions.In other words, memory for the non-presented target word can be the same asmemory for words that were actually presented to the participants.

Memory for presented words was improved in all experimental conditions whencompared to the control group, but this only reached signi®cance in the elaborationand chaining conditions. Thus the chaining mnemonic increased recall of list words aswas predicted. Similarly, the deeper level of processing associated with thinking aboutthe word meanings also improved memory for presented words.The personal experience and imagery conditions yielded no signi®cant memory

improvement, although there was a trend towards such improvement. This lack ofsigni®cant e�ect is perhaps not too surprising in the light of previous research.Imagery is an e�ective mnemonic device, but typically only when highly bizarreimages are created or when used systematically as part of a more general strategy suchas the pegword technique or the method of loci; on its own, it has seldom been shownto be e�ective. Relating words to personal experience is not a method that has beenstudied before, although other forms of self-referential encoding have been shown tobe e�ective (Rogers et al., 1977). The present research suggests that, in the formstudied here, it is not a powerful memory aid. It is perhaps worth remembering thatthese two manipulations were introduced primarily because of their potentialrelevance to the therapeutic situation, not because they were expected to be usefulmnemonic devices. In general, there was clear evidence that the experimental manipu-lation had been e�ective, at least with some of the groups.

In contrast, false memory production did not di�er signi®cantly between groups.Hence there was no evidence that making the words personally relevant or usingimagery had any e�ect on recall errors in this situation. Of course, this is not to claimthat these factors are not potentially signi®cant in a therapeutic situation. It ispossible that such e�ects exist but that the present experiment was not sensitiveenough to detect them. In addition, relating lists of words to one's own experiences isnot the same as attempting to recall a traumatic event from one's own childhood; noris conjuring up images of words the same as using guided imagery in a therapeuticsituation. Nevertheless, there is no evidence that the rather simplistic manipulationsused in the present study had any e�ect on recall errors.

The mnemonic devices of chaining and elaboration also had no e�ect on falsememory rates. Of these, the more surprising is elaboration, since Read (1996) claimedthat it tended to increase the occurrence of false memories. As mentioned in theintroduction, Read (1996) did not use a control group but instead compared elabora-tion to other rehearsal techniques. The present study indicates that, although elabora-tion may produce more false memory than other rehearsal techniques, it does not leadto more errors than standard presentation. It may also be relevant that Read (1996)asked participants to recall the words in the order presented while the present studyallowed free recall. Very di�erent strategies may be used when ordered recall is

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required. For example, participants might keep rehearsing the order of the words,rather than rehearsing each individual word in a more isolated manner. This maymean that the words in early list positions will receive considerable rehearsal, whilstlater words may get almost none. This could well in¯uence the probability of falserecall.

Like elaboration, chaining did not in¯uence false memory though both did a�ectrecall of the words actually presented. The fact that these manipulations in¯uencednormal recall indicates that they had an e�ect on coding and/or retrieval. Presumably,both led to a richer representation of the information presented. At an intuitive level,it is not clear what e�ect this should have on false memories. Increasing accuracy ofrecall of actual words might help people discriminate presented from non-presentedwords, thus decreasing false recall. In support of this contention, Bower and Clark(1969) found that when participants employed the chaining strategy in aiding memori-zation of list words, the recall of non-list words was rare (less than 0.5 per participant).Alternatively, these techniques might have led to much richer and interconnectedencodings in which the target words might be more readily activated, thus increasingfalse recall (c.f. Read, 1996). Our results do not allow us to distinguish between thesepossibilities; indeed, it is possible that they might both be true and have cancelled eachother out.

As indicated earlier, one thing that emerges very clearly from the present and fromprevious studies is that the illusory memory e�ect using the list-learning paradigm isextremely powerful and highly resistant to eradication. In the present study, manipu-lations that a�ected memory of the words actually presented (i.e. mnemonics) had noe�ect at all on false recall. It is also of interest that frequency of false recall does notcorrelate with memory ability, as measured by recall of words actually presented inthe lists. With the exception of Schacter et al. (1996), previous studies using thisparadigm have tended to use undergraduate students. The present ®ndings con®rmthe generality of the e�ect, that it occurs in younger age groups than have beenpreviously used, and that, within the range of ability used in this study, it seems to beunrelated to overall memory ability. The pervasiveness of the e�ect is furtherindicated by the ®nding that the great majority of participants (87%) produced one ormore illusory memories. It is certainly not an e�ect that is exclusive to the gullible orless intelligent.

The list-learning paradigm is potentially important in developing a better under-standing of the mechanisms by which false memories are induced. The best currentexplanation appears to be one based on spreading activation theories of memory(e.g. Collins and Loftus, 1975). These suggest that di�erent concepts are representedas nodes in a network, which are interconnected according to shared features andproperties. Presentation of aword activates its associated node, and activation spreadsfrom this node to other conceptually associated nodes within the network. Thus, inthe case of this experiment, presentation of all 15 list words is likely to activate thenode associated with the common non-presented word. The participant may confuseactivation of this node with having actually been presented with the word in the recallphase, and this may give rise to false memory.

Spreading activation theories have been criticized on the grounds that simplerexplanations are possible, for example based on the notion that memory is searchedusing information both about the test item and the context in which it occurs (the so-called compound cue model, Ratcli� and McKoon, 1988). Since this is a search

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model, it is less easily adapted to the recall task used in the present study than is thetheory of spreading activationÐ though such adaptations are no doubt possible.However, the task for any theory is to explain how words can be activated to such anextent that they are not only primed or recognized but actually deemed to have beenpresented. Deese (1959) has shown that the degree of association is one determinantof the occurrence of false memories, but more detailed information on the factors thatlead to illusory recall is needed. In the present study it was clear that the sleep, needleand sweet lists were much more e�ective in leading to illusory memories than the otherlists, but the exact reasons for this are not clear.

While it still contains many unknowns, the list-learning paradigm provides apotentially important and productive way of investigating hypotheses about thefactors in¯uencing false recall. The e�ects of relaxation, desensitization, and presenceof an authority ®gure can all be readily investigated using this paradigm. So, too,can factors that might decrease the occurrence of false memories, such as warningpeople of the possibility, or debrie®ng them after the session. The results cannot beimmediately generalized to the therapeutic situation, but at least they will indicatewhich factors are likely to be important. Thus this paradigm can be a rich source ofhypotheses, even though it is a far from perfect laboratory simulation. It wouldbe quite wrong, however, to use it on its own as the basis for practical decision making.

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Appendix A.

The six 15-word lists used in both the pilot study and the main experiment. Wordswere presented in the order shown

1. SLEEP 2. SWEET 3. MOUNTAINbed sour hillrest candy valleyawake sugar climbtired bitter summitdream good topwake taste molehillsnooze tooth peakblanket nice plaindoze honey glacierslumber soda goatsnore chocolate bikenap heart climberpeace cake rangeyawn tart steepdrowsy pie ski

4. NEEDLE 5. DOCTOR 6. CHAIRthread nurse tablepin sick siteye lawyer legssewing medicine seatsharp health couchpoint hospital deskprick dentist reclinerthimble physician sofahaystack ill woodthorn patient cushionhurt o�ce swivelinjection stethoscope stoolsyringe surgeon sittingcloth clinic rockingknitting cure bench

E�ects of Instructions on Memory Errrors 79

# 1998 John Wiley & Sons, Ltd. Appl. Cognit. Psychol. 12: 67±79 (1998)