- Email: [email protected]
Effects of modality on memory for original and misleading information
Acta Psychologica 140 (2012) 58–63
Contents lists available at SciVerse ScienceDirect
Acta Psychologica journal homepage: www.elsevier.com/ locate/actpsy
Effects of modality on memory for original and misleading information Katinka Dijkstra ⁎, Eelco M. Moerman Erasmus University of Rotterdam, The Netherlands
a r t i c l e
i n f o
Article history: Received 30 May 2011 Received in revised form 6 February 2012 Accepted 9 February 2012 Available online 28 March 2012 PsychInfo code: 2343 Keywords: Modality Misinformation Memory Motor encoding
a b s t r a c t This study examined the role of modality in correct recognition and misinformation acceptance in a naturalistic event cognition task that reflected an everyday life sequence of events. Participants heard, observed or acted out a sequence of events and were tested on memory for these events after being presented with an accurate description of the events or a description containing misinformation. The results indicated that recognition of unaltered information was higher in the enactment condition than the auditory or visual conditions and that this effect persisted over time. Misinformation acceptance for the immediate recognition test was lowest in the auditory condition but this advantage disappeared over time. Modality congruence of the auditory condition with the modality in which misinformation was presented and different retrieval processes underlying recognition of altered and unaltered information may explain these findings. © 2012 Elsevier B.V. All rights reserved.
1. Introduction Three decades ago, the first studies on the enactment effect were published (Bäckman & Nilsson, 1985; Cohen, 1983; Zimmer & Engelkamp, 1985). The enactment effect is a modality effect of enhanced recall of stimuli (i.e. raise your hand) that are physically acted out (subject-performed) relative to verbally encoded items that are read (Engelkamp & Cohen, 1991; Nilsson & Bäckman, 1991; Nyberg, Nilsson, & Bäckman, 1991). Advantages of enactment over verbally encoded stimuli have since been demonstrated in various populations, such as older adults (Bäckman & Nilsson, 1985; Dijkstra, MacMahon, & Misirlisoy, 2008; Spranger, Schatz, & Knopf, 2008), adults with Alzheimer's disease (Masumoto, Takai, Tsuneto, & Kashiwagi, 2004), and children (Cohen & Stewart, 1982). Despite these solid findings, there has been no agreement among researchers on what mechanism seems to be driving the effect. The explanations that have been offered either center around the motor component of enacted items (Engelkamp & Cohen, 1991; von Essen & Nilsson, 2003) and multimodal encoding processes (Bäckman, 1985; Bäckman & Nilsson, 1985), or episodic integration of these items as a result of strategic conceptual encoding (Kormi-Nouri, 2000; Spranger et al., 2008). According to the motor encoding view, the motor system is activated during enactment. This enhances encoding of item-specific information and results in a free recall advantage for these items because movements are distinct for separate actions. A kick or wave action are ⁎ Corresponding author at: Dept. of Psychology, Erasmus University Rotterdam, P. O. Box 1738, 3000 DR Rotterdam, The Netherlands. Tel.: +31 10 4088657; fax: +31 10 408 9009. E-mail address: [email protected] (K. Dijkstra). 0001-6918/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.actpsy.2012.02.003
different motorically whereas they share common features verbally and visually. Movement may be a visual feature they share. Verbs depicting an action may be a common verbal feature. Verbal and visual encoding processes therefore allow relational encoding to occur based on common aspects of the items (Spranger et al., 2008; Zimmer & Engelkamp, 1985). This view is supported by research demonstrating better free recall of enacted sentences than verbally and visually encoded materials except when a secondary motor task is involved (Engelkamp & Cohen, 1991). This suggests that the motor component is relevant for encoding. If motor encoding were irrelevant, the secondary motor task would not have caused interference. A different explanation of the enactment effect is the episodic integration view. According to this view, higher self involvement of participants during enactment relative to verbal and visual encoding should result in better integration of action events during the encoding process (Knopf, Mack, Lenel, & Ferrante, 2005; Kormi-Nouri, 1995). For example, when participants were asked to mentally plan actions for another person, recall was as high under this imaginary condition as under an enactment condition (Kormi-Nouri, 2000). Strategic planning and item integration rather than motor encoding could constitute the enactment effect (Kormi-Nouri, 2000; Spranger et al., 2008). Compared to the other explanations of the enactment effect, the motor encoding view fits well with new developments in research, such as sign language (von Essen & Nilsson, 2003) and brain-imaging research (Nilsson et al., 2000; Nyberg et al., 2001) and the embodied cognition approach (Barsalou, 2008). Brain-imaging research has demonstrated how brain regions that were active during subject performed tasks were reactivated when the same type of materials were retrieved (Nyberg et al., 2001). Increased brain activity due to retrieval processes following enactment has been demonstrated in the right motor cortex
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63
and was higher after enactment than after imaginary and verbal encoding (Nilsson et al., 2000). This finding contradicts the episodic integration view because it would predict similar instead of different outcomes for imaginary and actual movement encoding as both involve the same kind of planning. The benefits of enactment appear to extend to another type of memory task, a false recognition task (Worthen & Wood, 2001). False recognition of unusual or common action phrases was lower for enacted phrases than for verbally encoded items (Engelkamp, Zimmer, Mohr, & Sellen, 1994). False recognition was also higher for imagined than performed action phrases (Worthen & Wood, 2001). These findings support the motor encoding view because enactment was the only difference between imagined and performed conditions and recognition was largely independent of the type of phrases (common or unusual). Based on the findings discussed above, motor encoding seems to benefit memory performance for different types of memory tasks, recall for previously encoded action items, and recognition performance that requires discrimination between earlier presented and not earlier presented but related (false) action phrases. The goal of the present study was to extend the enactment effect to another domain of research, the misinformation paradigm, and with more naturalistic stimulus materials consisting of a sequence of events. So far, research on the enactment effect has used action phrases that are generally unrelated. The naturalistic task used in the current study was a sequence of actions that together formed a coherent story. This type of stimulus materials better reflects our everyday experience of listening to or watching a story followed by misleading information that may lead to incorporation of this misinformation in our memory of the event. The incorporation of misleading post-event information in the recollection of an experience can be manipulated and tested in a misinformation paradigm. In a misinformation paradigm, participants are presented with information regarding a sequence of events after which one group of participants is exposed to misinformation regarding some of the events, whereas another group does not receive misinformation. Subsequently, participants answer questions on a forced-choice recognition task in which some of the answers contain the misleading information. Participants previously exposed to misleading information may not remember the original information because it may be overwritten by the misinformation (Loftus, 2005). Alternatively, they may no longer have access to the original information (Ayers & Reder, 1998), or have forgotten the source of it (Lindsay & Johnson, 1989). In all cases, they tend to accept the answers containing misinformation. The current study utilized the misinformation paradigm to test a strong motor encoding view. If enactment encoding results in a particularly strong and distinctive memory trace for earlier processed information based on the involvement of motor movement during the encoding process, then misleading information presented later should have a lesser impact than modalities that do not involve motor encoding, such as verbal and visual modalities. Such an outcome would also extend findings from previous research on enactment benefits in free recall tasks (Engelkamp & Cohen, 1991) and unrelated action items (Engelkamp, Zimmer, & Denis, 1989; Koriat, Ben-Zur, & Druch, 1991; Spranger et al., 2008). Assessing an enactment advantage under conditions of misinformation can be considered a strong view of motor encoding because enactment can be tested as a “protective strategy” to resist acceptance of misleading information. In addition to an enhancement of encoded stimuli material through enactment, which can be considered the standard motor encoding view, enactment as protective strategy to resist misleading information involves an extra step, that of comparing the original information with the misleading information. If enactment results in a more elaborate memory trace for the stimuli materials during the encoding phase, then chances are smaller that there is no longer access to the source of information or that misleading information overwrites the original information. A benefit of enactment under those conditions would extend earlier findings on lower false recognition rates under an enactment condition relative to a verbal and an imagine condition (Worthen & Wood, 2001).
59
2. Methods 2.1. Participants A total of 115 participants (82% female) took part in both sessions of the study (mean age = 20.4, SD = 2.9, range 17–42). Data from several participants had to be removed from the data set. Three participants had participated twice 1; three participants were removed because of procedural errors, and two participants were close to guessing the purpose of the study. Their data were removed as well. All participants received course credit for their participation. 2.2. Stimuli Participants were randomly assigned to one of three conditions in which they were presented with an action sequence of a man visiting a friend at home. In the auditory condition, participants listened to a story of a man visiting his friend (no visual enhancement). In the visual condition, participants observed a series of slides presenting a man visiting his friend (no verbal enhancement). The enactment condition differed from the visual condition in the sense that participants performed the action presented on the slide (i.e. pushing the door) in addition to observing the slide of the visitor pushing the door.2 In other words, actions were mimicked in the absence of actual objects but as if they were present. Appendix A displays examples of the stimuli materials. The presentation rate of the stimuli materials was the same for each modality. Each slide contained one action and was presented for the duration of 4 s in the visual and enactment modalities. The same amount of time was spent on the verbal description of the same action in the auditory condition. The total presentation time was around 3 min across all modalities. 2.3. Procedure Similar to misinformation studies conducted earlier (Loftus, Miller, & Burns, 1978), the experiment consisted of three phases: 1) presentation of stimuli; 2) presentation of misleading information; and 3) a multiple choice test containing correct and misleading answers. Immediately after participants listened to, watched, and/or acted out the series of events, they read a written account of the same events on the computer screen. Misleading information was incorporated into the written account of events (misinformation condition) or not (control condition).3 Appendix A shows an example. After the filler task, that took about 20 min to complete to allow for consolidation of the misinformation, participants answered 20 questions on a multiple choice test. Sixteen questions contained one correct and two incorrect alternatives that did not reflect any misleading information. The correct recognition score was computed on these questions. Four questions were biased by misleading information from the script. Misinformation acceptance was scored as the number of misinformation-containing answers chosen for the total number of misinformation-containing questions. There were four versions of the recognition task with questions being presented in different orders. The questions containing misleading answers were never at the very beginning or end of the questionnaire nor were they close to other questions with misleading 1 The experiment was combined with two other experiments. Therefore, participants who conducted the study in one experiment could potentially be part of the experiment again when participating in another experiment. None of the participants reported prior participation. 2 The addition of an auditory condition with enactment was considered but not implemented because piloting revealed that it was too difficult for participants to enact the scenes without visual input. In the vision condition, participants imitated the action performed by the person on the slide. 3 An reading modality for the presentation of misinformation and control condition was chosen in order to avoid overlap with the auditory encoding condition.
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63
answers. Errors were scored as the number of incorrect (but not misleading) alternatives chosen from the questions containing misleading answers. They could only be calculated for questions containing misleading answers because for the other questions, no misleading answers were involved, hence participants could not be confused by a misleading answer. Appendix B displays examples of these questions and answers. At the end of the experiment, participants filled in two questionnaires, the CEV (Creatieve Ervaringen Vragenlijst — Creative Experiences Questionnaire, Merckelbach, Muris, Rassin, & Horselenberg, 2000, Cronbach's α = 0.79) and the DES (Dissociative Experiences Scale, Boon & Draijer, 1995). The CEV consists of 25 questions that assess one's proneness to fantasy/imagination. Participants with high scores can easily imagine situations that are not real. About 10% of the population has high scores on this measure and in some studies, it has been found to correlate positively with false memory acceptance (Merckelbach et al., 2000). The DES contains 28 questions on dissociative symptoms, such as memory distortion and depersonalization. Individuals with high scores tend to be more susceptible to misinformation acceptance (Merckelbach et al., 2000, Cronbach's α = 0.89). These measures were included to assess whether they would correlate with misinformation acceptance. To assess the role of modality in correct recognition and misinformation acceptance over time, participants were asked to answer the same questions two weeks later (presented in a different order) in a surprise recognition test. If the enactment effect can be demonstrated under these conditions, an effect over a delay would also demonstrate consolidation of the effect. Earlier research demonstrated longerterm benefits of an enactment effect over a period of two weeks in free recall over verbal and visual conditions (Dijkstra et al., 2008). Predictions based on a motor encoding view were that the enactment condition would yield better recognition memory than the auditory and visual condition, definitely for correct recognition of items based on unaltered information (standard motor encoding view), and possibly also for lower misinformation acceptance for answers to items that reflected misleading information (strong motor encoding view). Motor encoding of events involves processing of distinct actions which makes them easier to recognize later whereas verbal and visual encoding allows relational encoding which could impede recognition of specific events. The episodic integration view would not predict an enactment advantage for immediate or delayed recognition memory, correct memory or misinformation acceptance, because strategic processing would not be possible in the current experimental set-up. Participants enacted a sequence of events that was already presented visually and therefore did not involve any planning of actions.
16
immediate
12 10 8 6 4 2 0
visual
auditory
enactment
Fig. 1. Number of items recognized correctly among all participants across modalities and retention interval. Error bars represent standard error.
conditions. Subsequent comparisons specifically showed better immediate, t(73)= 2.86, p b .01, and delayed memory, t(74) = 4.51, p b .001, in the enactment than in the visual condition. The same was shown for enactment relative to the auditory condition, for immediate, t(54) = 2.15, pb .05, and delayed memory, t(47)= 4.11, p b .001 There was no difference in immediate or delayed memory between the auditory and visual conditions (tb 1). The second hypothesis dealt with the role of modality in misinformation acceptance and predicted lower misinformation acceptance in immediate and delayed retrieval tasks and fewer errors in the enactment condition. To test this hypothesis, two repeated measures ANOVAS were conducted on all participants who completed the immediate and delayed recognition test. Both analyses were conducted on performance on misinformation containing questions. The first analysis involved the scores of misinformation acceptance, the second analysis included only the errors made on these questions (i.e. choice for the incorrect but not misinformation containing answer). Fig. 2 presents the results with regard to misinformation acceptance. A mixed analysis of variance showed a main effect of time interval, F(1, 101) = 4.17, p b .05, η 2 = .040, a main effect of misinformation manipulation, F(1, 101) = 62.25, p b .001, η 2 = .381, and a marginal three-way interaction of interval by condition by manipulation, F(1, 101) = 2.50, p = .087, η 2 = .049. Because an enactment benefit was predicted specifically with regard to the misinformation condition, a separate analysis was conducted among a subset of participants
3. Results
4
# items accepted
immediate
The design was a 3 (modality: auditory, visual or enactment) by 2 (misinformation versus no misinformation) by 2 (retention: immediate versus delayed) mixed design with modality and misinformation as between subjects factors and retention interval as within subjects factor. The first hypothesis addressed the role of modality on correct memory of stimuli materials over time. To test this hypothesis a repeated measures ANOVA was conducted on all participants who completed the immediate and delayed recognition test for unaltered information. Fig. 1 presents the results. A mixed ANOVA with factors of condition (auditory, visual, enactment), manipulation (misinformation, control), and retention interval (immediate, delayed) showed a main effect of retention interval, F(1, 102) = 60.07, p b .001, η 2 = .373, a main effect of condition, F(2, 101) = 10.33, p b .01, η2 = .170, and a condition by time interval interaction, F(2, 101) = 5.25, p b .01, η2 = .094, on memory of items without misleading answers. Tukey post-hoc tests indicated differences between the enactment and visual condition and auditory
delayed
14
# items
60
delayed
3
2
1
0 auditory
visual
enactment
Fig. 2. Number of answers accepted containing misinformation by participants exposed to misinformation across modalities and retention interval. Error bars represent standard error.
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63
who received misleading information. This mixed analysis of variance showed no main effect of condition or retention interval but a condition by retention interval interaction, F(2, 54) = 3.22, p b .05, η 2 = .107, on misinformation acceptance. Misinformation acceptance was lowest initially in the auditory condition relative to the visual, t(30) = 2.89, p b .01, and enactment condition, t(40) = 2.07, p b .05, but increased significantly from immediate to delayed retrieval in the auditory condition, t(16) = 2.50, p b .05. There were no differences between conditions for delayed retrieval, nor were there other changes in misinformation acceptance over time for the visual and enactment condition. To assess if the misinformation confused participants to the extent that they chose an answer that was neither correct nor the answer containing misinformation, additional analyses were conducted to assess the role of modality on errors as those answers could reflect source attribution errors. An ANOVA on errors in the misinformation condition demonstrated no condition by retention interval interaction nor a main effect of retention interval but a main effect of condition, F(2, 55) = 3.60, p b .05, η 2 = .116. Only the visual and enactment conditions differed here, with fewer errors in the enactment than visual condition for immediate and delayed error performance, t(39) = 2.17, p b .05, and t(39) = 2.27, p b .05. To test long-term effects of modality on correct recall and misinformation acceptance, a different group of 59 participants was exposed to the same manipulation as described above with the exception that no immediate recognition test was given, only a delayed recognition test. A one-way ANOVA on correct recognition showed a main effect of condition, F(2, 56) = 4.73, p b .05. Tukey post-hoc comparisons indicated differences between the enactment and auditory conditions. Subsequent comparisons showed higher performance on recognition of unaltered items under conditions of enactment relative to auditory encoding., t(37) = 2.64, p b .05. There was no effect of condition on misinformation acceptance after a delay. The pattern was similar to that of the results described earlier although the samples differed in performance on recognition of unaltered information with an advantage of the sample being exposed to a pretest, t(165) = 5.21. Finally, to test very long-term effects of modality on correct recall and misinformation acceptance, participants were contacted after a year to answer the same questions as for immediate and delayed recall. Only a subset of these participants responded (27), which means that these data must be interpreted with caution. Nevertheless, a mixed ANOVA with factors of condition (auditory, visual, enactment), manipulation (misinformation, control), and retention interval (immediate, short delay, long delay) showed a main effect of interval, multivariate 16
auditory
visual
61
F(2, 42) = 22.70, p b .001, η2 = .760, and condition, F(2, 21) = 3.937, p b .05, η2 = .275, and a three-way interaction of condition by misinformation manipulation by retention interval, F(2, 85) = 2.85, p b .05, η2 = .213. The results are presented in Fig. 3. Subsequent analyses were conducted to describe the pattern of results. Recognition memory decreased over time, from immediate recognition to the year-delay, t(26) = 8.46, p b .001, and from two-week delay recognition to the year delay, t(26)= 7.32, p b .001. A post-hoc test for condition indicated differences between the auditory and enactment conditions. This pattern was modulated by the misinformation manipulation. For the auditory condition, differences in recognition memory from immediate or two-week delay to one year delay only occurred for participants who were not exposed to misinformation, whereas those differences always occurred for the enactment condition. A mixed analysis of variance on misinformation acceptance with the three time intervals only showed a main effect of manipulation, F(1, 21) = 10.46, p b .01, η 2 = .333 with higher misinformation acceptance in the misleading condition (M = .38, SE = .036) than in the control condition (M = .19, SE = .036). To assess whether misinformation acceptance or errors correlated with proneness to fantasy or dissociative experiences, bivariate correlation analyses were conducted with these measures and misinformation acceptance and error scores. There were significant correlations between CEV and DES scores, r(50) = .330, p b .05 and between errors in immediate retrieval, r(53) = .297, p b .05. Proneness to fantasy may contribute to confusion regarding the correct answer for questions containing misleading answers. 4. Discussion We examined the role of encoding modality in correct recognition of questions containing no misleading answers, misinformation acceptance, and errors. The strong version of the motor encoding view predicted an enactment advantage for recognition on each of these measures, whereas the standard version of this view predicted an enactment advantage only for recognition for unaltered information. The results with regard to memory for unaltered information supported the standard version of the motor encoding view. The modality by retention interval interaction showed a distinct advantage of the enactment modality as expected, both in immediate and delayed recognition relative to the auditory and visual conditions. In other words, participants who had acted out the events they observed on the slides had better immediate and delayed recognition than participants who had only watched the events or listened to an auditory
enactment
14 12
# items
10 8 6 4 2 0 immediate
two-week
one year
no misinformation
immediate
two-week
one year
misinformation
Fig. 3. Number of items recognized correctly among all participants who responded after a year across modalities, misinformation conditions, and retention interval. Error bars represent standard error.
62
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63
version of the events. Although recognition performance generally deteriorated over time, recognition under enactment was spared over time compared to the other conditions. An additional analysis to assess performance with a different group of participants who did not get an immediate recognition task revealed better memory performance under enactment than auditory encoding conditions. This also supports the standard encoding view. An enactment benefit is still present when the recognition test is administered for the first time after two weeks instead of after the filler task during the same session as when (misleading) post-event information is presented. Longer term effects of encoding, after one year, were assessed as well with a subset of the original group of participants. The results showed a three-way interaction of the relevant variables, suggesting an overall pattern of forgetting that can be expected, but also a reduction of the enactment benefit in the misinformation condition. Although the results need to be interpreted with caution because of the small sample size, it is reasonable to assume that to some extent, confusion caused by misinformation led to a certain level of contamination of answers to questions that never contained any misleading answers. Future research could resolve this issue. The enactment advantage is consistent with results of other studies that demonstrated a benefit of enactment in immediate and delayed recall in comparison with a visual modality (Dijkstra et al., 2008). These studies have demonstrated benefits of enactment over verbal encoding in immediate and delayed recall over a week (Manzi & Nigro, 2008) or cued recall after a two week retention period (Dijkstra et al., 2008). They are also consistent with research showing better recall with non-literal enactment compared to standard verbal learning (Noice & Noice, 2007). No other studies have compared as of yet an auditory modality with a visual and enactment modality for recognition performance of an event sequence with related events. The rather small decline in recognition over time in the enactment modality demonstrates that enactment is not just a benefit of encoding but goes beyond that. This finding is consistent with a nonstrategic explanation of the enactment effect that emphasizes the enhanced item-specific processing and facilitation due to motor encoding during enactment. It is not consistent with an episodic integration view because selfinvolvement and strategic processing were not possible under these experimental conditions. Participants imitated what they saw and therefore could not plan their own actions. This means that any facilitation of encoding for performance was due to enactment. This is an important finding as it illustrates that motor encoding is a reliable, robust effect even when stimuli materials are action sequences. Moreover, it is an effect that holds over a time period of two weeks (but not one year) and without an immediate testing condition. The second prediction tested the strong version of the motor encoding view, a reduction of misinformation acceptance under conditions of enactment. This hypothesis was only partially supported. For immediate recognition, the results indicated a lower rate of misinformation acceptance in the auditory instead of the enactment condition. Even though misinformation acceptance increased significantly in the auditory condition over time, and although errors were lower for delayed recognition performance in the enactment condition, the expected enactment advantage was absent. How can we explain this unexpected role of an auditory modality advantage and a lack of enactment benefit to reduce misinformation acceptance? A possible explanation for this result is modality congruity. A modality congruity of matching encoding and retrieval modalities could facilitate performance and overrule benefits of other modalities. Results of a recent study showed lower false memory acceptance under modality congruent retrieval conditions, oral recall of auditorily presented stimuli (Rummer, Schweppe, & Martin, 2009). Although there was no exact modality match in the current study because the encoding modality was auditory and the script (with or
without misinformation) and recognition test were written, encoding and retrieval conditions were nevertheless closer in modality (a verbal modality) than the visual and enactment encoding conditions. The auditory account of the event sequence likely resulted in the creation of a situation model (a mental representation of the state of affairs of the events) that is normally established after reading or listening to a narrative (Zwaan, 1996). Comparing this representation with a written account of this sequence would reveal inconsistencies with the original information more easily than when modality-different representations are compared. This representation may be most coherent shortly after its formation, and consequently, not be as reliable for comparison after a time period of two weeks. Discrepancies between the original representation based on the auditory account and delayed recognition test should be less noticeable then and this is supported by the data that no longer show a benefit of auditory encoding after the retention period of two weeks. Our conclusion has to be that the strong version of the enactment hypothesis cannot be maintained in the context of a misinformation paradigm. Motor encoding does not provide protection against misinformation acceptance in comparison to encoding modalities that globally match in encoding and retrieval. Future studies should therefore test how the enactment advantage will hold up in a design for which the encoding modalities and modality in which post-event information is presented are entirely different. This study has presented further evidence for the motor encoding view by demonstrating benefits of enactment in immediate and delayed retrieval for unaltered information that cannot be attributed to other elements in the encoding process. A contribution to the field of research is that the enactment benefit has been demonstrated with naturalistic stimulus materials: an action sequence of related events. A possible application of these findings could be to implement an enactment component in more everyday tasks for which recall or recognition of action sequences are required. A suitable domain to implement enactment as part of the learning process is an educational setting. The long term benefits of enactment, demonstrated in this study, should be particularly beneficial for long term retention. Acknowledgments Funding for this study was provided by a Toptalent grant from the Department of Social Sciences at the Erasmus University of Rotterdam. The author wishes to acknowledge the help of Shima Kia, Sander Lambellais, Eelco Moerman, Nynke van Oostrom, Lysanne Post, and Michel Quak in the data collection. Appendix A. Supplementary data Supplementary data to this article can be found online at doi:10. 1016/j.actpsy.2012.02.003. References Ayers, M. S., & Reder, L. M. (1998). A theoretical review of the misinformation effect: predictions from an activation-based memory model. Psychonomic Bulletin & Review, 5, 1–21. Bäckman, L. (1985). Further evidence for the lack of adult age differences on free recall of subject-performed tasks: The importance of motor action. Human Learning, 4, 79–87. Bäckman, L., & Nilsson, L. -G. (1985). Prerequisites for the lack of age differences in memory performance. Experimental Aging Research, 11, 67–73. Barsalou, L. W. (2008). Grounded cognition. Annual Review of Psychology, 59, 617–645. Boon, S., & Draijer, N. (1995). Screening en diagnostiek van dissociatieve stoornissen. Lisse: Swets & Zeitlinger. Cohen, R. L. (1983). The effect of encoding variables on the free recall of words and action events. Memory & Cognition, 12, 633–641. Cohen, R. L., & Stewart, M. (1982). How to avoid developmental effects in free-recall? Scandinavian Journal of Psychology, 24, 9–15. Dijkstra, K., MacMahon, C., & Misirlisoy, M. (2008). The effects of golf expertise and presentation modality on memory for golf and everyday items. Acta Psychologica, 128, 298–303.
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63 Engelkamp, J., & Cohen, R. L. (1991). Current issues in memory of action events. Psychological Research, 53, 175–182. Engelkamp, J., Zimmer, H. D., & Denis, M. (1989). Paired-associate learning of action verbs with visual-imagined or motor-imaginal encoding instructions. Psychological Research, 50, 257–263. Engelkamp, J., Zimmer, H. D., Mohr, G., & Sellen, O. (1994). Memory of self-performed tasks — Self performing during recognition. Memory & Cognition, 22, 34–39. Knopf, M., Mack, W., Lenel, A., & Ferrante, S. (2005). Memory for action events: Findings in neurological patients. Scandinavian Journal of Psychology, 46, 11–19. Koriat, A., Ben-Zur, H., & Druch, A. (1991). The contextualization of input and output events in memory. Psychological Research, 53, 260–270. Kormi-Nouri, R. (1995). The nature of memory for action events: An episodic integration view. European Journal of Cognitive Psychology, 11, 337–363. Kormi-Nouri, R. (2000). The role of movement and object in action memory: A comparative study between blind, blindfolded and sighted subjects. Scandinavian Journal of Psychology, 41, 71–75. Lindsay, D. S., & Johnson, M. K. (1989). The eyewitness suggestibility effect and memory for source. Memory & Cognition, 17, 349–358. Loftus, E. F. (2005). A 30-year investigation of the malleability of memory. Learning and Memory, 12, 361–366. Loftus, E. F., Miller, D. G., & Burns, H. J. (1978). Semantic integration of verbal information into a visual memory. Journal of Experimental Psychology: Human Learning and Memory, 4, 19–31. Manzi, A., & Nigro, G. (2008). Long-term memory for performed and observed actions: Retrieval awareness and source monitoring. Memory, 16, 595–603. Masumoto, K., Takai, T., Tsuneto, S., & Kashiwagi, T. (2004). Influence of motoric encoding on forgetting function on memory for action sentences in patients with Alzheimer's disease. Perceptual and Motor Skills, 98, 299–306.
63
Merckelbach, H., Muris, P., Rassin, E., & Horselenberg, R. (2000). Dissociative experiences and interrogative suggestibility in college students. Personality and Individual Differences, 293, 1133–1140. Nilsson, L. G., & Bäckman, L. (1991). Encoding dimensions of subject-performed tasks. Psychological Research, 53, 212–218. Nilsson, L. G., Nyberg, L., Klingberg, T., Aberg, C., Persson, J., & Roland, P. E. (2000). Activity in motor areas while remembering action events. NeuroReport, 11, 2199–2201. Noice, H., & Noice, T. (2007). The non-literal enactment effect. Filling in the blanks. Discourse Processes, 44, 73–89. Nyberg, G., Nilsson, L. G., & Bäckman, L. (1991). A component analysis of action events. Psychological Research, 53, 219–225. Nyberg, L., Petersson, K. M., Nilsson, L. G., Sandblom, J., Aberg, C., & Ingvar, M. (2001). Reactivation of motor brain areas during explicit memory for actions. NeuroImage, 14, 521–528. Rummer, R., Schweppe, J., & Martin, R. C. (2009). A modality congruency effect in verbal false memory. European Journal of Cognitive Psychology, 21, 473–483. Spranger, T., Schatz, T. R., & Knopf, M. (2008). Does action make you faster? A retrievalbased approach to investigating the origins of the enactment effect. Scandinavian Journal of Psychology, 49, 487–495. von Essen, J. D., & Nilsson, L. -G. (2003). Memory effects of motor activation in subjectperformed tasks and sign language. Psychonomic Bulletin & Review, 10, 445–449. Worthen, J. B., & Wood, V. V. (2001). Memory discrimination for self-performed and imagined acts: Bizarreness effects in false recognition. The Quarterly Journal of Experimental Psychology, 54, 49–67. Zimmer, H. D., & Engelkamp, J. (1985). An attempt to distinguish between kinematic and motor memory components. Acta Psychologica, 58, 81–106. Zwaan, R. A. (1996). Processing narrative time shifts. Journal of Experimental Psychology: Learning, Memory, and Cognition, 22, 1196–1207.
Contents lists available at SciVerse ScienceDirect
Acta Psychologica journal homepage: www.elsevier.com/ locate/actpsy
Effects of modality on memory for original and misleading information Katinka Dijkstra ⁎, Eelco M. Moerman Erasmus University of Rotterdam, The Netherlands
a r t i c l e
i n f o
Article history: Received 30 May 2011 Received in revised form 6 February 2012 Accepted 9 February 2012 Available online 28 March 2012 PsychInfo code: 2343 Keywords: Modality Misinformation Memory Motor encoding
a b s t r a c t This study examined the role of modality in correct recognition and misinformation acceptance in a naturalistic event cognition task that reflected an everyday life sequence of events. Participants heard, observed or acted out a sequence of events and were tested on memory for these events after being presented with an accurate description of the events or a description containing misinformation. The results indicated that recognition of unaltered information was higher in the enactment condition than the auditory or visual conditions and that this effect persisted over time. Misinformation acceptance for the immediate recognition test was lowest in the auditory condition but this advantage disappeared over time. Modality congruence of the auditory condition with the modality in which misinformation was presented and different retrieval processes underlying recognition of altered and unaltered information may explain these findings. © 2012 Elsevier B.V. All rights reserved.
1. Introduction Three decades ago, the first studies on the enactment effect were published (Bäckman & Nilsson, 1985; Cohen, 1983; Zimmer & Engelkamp, 1985). The enactment effect is a modality effect of enhanced recall of stimuli (i.e. raise your hand) that are physically acted out (subject-performed) relative to verbally encoded items that are read (Engelkamp & Cohen, 1991; Nilsson & Bäckman, 1991; Nyberg, Nilsson, & Bäckman, 1991). Advantages of enactment over verbally encoded stimuli have since been demonstrated in various populations, such as older adults (Bäckman & Nilsson, 1985; Dijkstra, MacMahon, & Misirlisoy, 2008; Spranger, Schatz, & Knopf, 2008), adults with Alzheimer's disease (Masumoto, Takai, Tsuneto, & Kashiwagi, 2004), and children (Cohen & Stewart, 1982). Despite these solid findings, there has been no agreement among researchers on what mechanism seems to be driving the effect. The explanations that have been offered either center around the motor component of enacted items (Engelkamp & Cohen, 1991; von Essen & Nilsson, 2003) and multimodal encoding processes (Bäckman, 1985; Bäckman & Nilsson, 1985), or episodic integration of these items as a result of strategic conceptual encoding (Kormi-Nouri, 2000; Spranger et al., 2008). According to the motor encoding view, the motor system is activated during enactment. This enhances encoding of item-specific information and results in a free recall advantage for these items because movements are distinct for separate actions. A kick or wave action are ⁎ Corresponding author at: Dept. of Psychology, Erasmus University Rotterdam, P. O. Box 1738, 3000 DR Rotterdam, The Netherlands. Tel.: +31 10 4088657; fax: +31 10 408 9009. E-mail address: [email protected] (K. Dijkstra). 0001-6918/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.actpsy.2012.02.003
different motorically whereas they share common features verbally and visually. Movement may be a visual feature they share. Verbs depicting an action may be a common verbal feature. Verbal and visual encoding processes therefore allow relational encoding to occur based on common aspects of the items (Spranger et al., 2008; Zimmer & Engelkamp, 1985). This view is supported by research demonstrating better free recall of enacted sentences than verbally and visually encoded materials except when a secondary motor task is involved (Engelkamp & Cohen, 1991). This suggests that the motor component is relevant for encoding. If motor encoding were irrelevant, the secondary motor task would not have caused interference. A different explanation of the enactment effect is the episodic integration view. According to this view, higher self involvement of participants during enactment relative to verbal and visual encoding should result in better integration of action events during the encoding process (Knopf, Mack, Lenel, & Ferrante, 2005; Kormi-Nouri, 1995). For example, when participants were asked to mentally plan actions for another person, recall was as high under this imaginary condition as under an enactment condition (Kormi-Nouri, 2000). Strategic planning and item integration rather than motor encoding could constitute the enactment effect (Kormi-Nouri, 2000; Spranger et al., 2008). Compared to the other explanations of the enactment effect, the motor encoding view fits well with new developments in research, such as sign language (von Essen & Nilsson, 2003) and brain-imaging research (Nilsson et al., 2000; Nyberg et al., 2001) and the embodied cognition approach (Barsalou, 2008). Brain-imaging research has demonstrated how brain regions that were active during subject performed tasks were reactivated when the same type of materials were retrieved (Nyberg et al., 2001). Increased brain activity due to retrieval processes following enactment has been demonstrated in the right motor cortex
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63
and was higher after enactment than after imaginary and verbal encoding (Nilsson et al., 2000). This finding contradicts the episodic integration view because it would predict similar instead of different outcomes for imaginary and actual movement encoding as both involve the same kind of planning. The benefits of enactment appear to extend to another type of memory task, a false recognition task (Worthen & Wood, 2001). False recognition of unusual or common action phrases was lower for enacted phrases than for verbally encoded items (Engelkamp, Zimmer, Mohr, & Sellen, 1994). False recognition was also higher for imagined than performed action phrases (Worthen & Wood, 2001). These findings support the motor encoding view because enactment was the only difference between imagined and performed conditions and recognition was largely independent of the type of phrases (common or unusual). Based on the findings discussed above, motor encoding seems to benefit memory performance for different types of memory tasks, recall for previously encoded action items, and recognition performance that requires discrimination between earlier presented and not earlier presented but related (false) action phrases. The goal of the present study was to extend the enactment effect to another domain of research, the misinformation paradigm, and with more naturalistic stimulus materials consisting of a sequence of events. So far, research on the enactment effect has used action phrases that are generally unrelated. The naturalistic task used in the current study was a sequence of actions that together formed a coherent story. This type of stimulus materials better reflects our everyday experience of listening to or watching a story followed by misleading information that may lead to incorporation of this misinformation in our memory of the event. The incorporation of misleading post-event information in the recollection of an experience can be manipulated and tested in a misinformation paradigm. In a misinformation paradigm, participants are presented with information regarding a sequence of events after which one group of participants is exposed to misinformation regarding some of the events, whereas another group does not receive misinformation. Subsequently, participants answer questions on a forced-choice recognition task in which some of the answers contain the misleading information. Participants previously exposed to misleading information may not remember the original information because it may be overwritten by the misinformation (Loftus, 2005). Alternatively, they may no longer have access to the original information (Ayers & Reder, 1998), or have forgotten the source of it (Lindsay & Johnson, 1989). In all cases, they tend to accept the answers containing misinformation. The current study utilized the misinformation paradigm to test a strong motor encoding view. If enactment encoding results in a particularly strong and distinctive memory trace for earlier processed information based on the involvement of motor movement during the encoding process, then misleading information presented later should have a lesser impact than modalities that do not involve motor encoding, such as verbal and visual modalities. Such an outcome would also extend findings from previous research on enactment benefits in free recall tasks (Engelkamp & Cohen, 1991) and unrelated action items (Engelkamp, Zimmer, & Denis, 1989; Koriat, Ben-Zur, & Druch, 1991; Spranger et al., 2008). Assessing an enactment advantage under conditions of misinformation can be considered a strong view of motor encoding because enactment can be tested as a “protective strategy” to resist acceptance of misleading information. In addition to an enhancement of encoded stimuli material through enactment, which can be considered the standard motor encoding view, enactment as protective strategy to resist misleading information involves an extra step, that of comparing the original information with the misleading information. If enactment results in a more elaborate memory trace for the stimuli materials during the encoding phase, then chances are smaller that there is no longer access to the source of information or that misleading information overwrites the original information. A benefit of enactment under those conditions would extend earlier findings on lower false recognition rates under an enactment condition relative to a verbal and an imagine condition (Worthen & Wood, 2001).
59
2. Methods 2.1. Participants A total of 115 participants (82% female) took part in both sessions of the study (mean age = 20.4, SD = 2.9, range 17–42). Data from several participants had to be removed from the data set. Three participants had participated twice 1; three participants were removed because of procedural errors, and two participants were close to guessing the purpose of the study. Their data were removed as well. All participants received course credit for their participation. 2.2. Stimuli Participants were randomly assigned to one of three conditions in which they were presented with an action sequence of a man visiting a friend at home. In the auditory condition, participants listened to a story of a man visiting his friend (no visual enhancement). In the visual condition, participants observed a series of slides presenting a man visiting his friend (no verbal enhancement). The enactment condition differed from the visual condition in the sense that participants performed the action presented on the slide (i.e. pushing the door) in addition to observing the slide of the visitor pushing the door.2 In other words, actions were mimicked in the absence of actual objects but as if they were present. Appendix A displays examples of the stimuli materials. The presentation rate of the stimuli materials was the same for each modality. Each slide contained one action and was presented for the duration of 4 s in the visual and enactment modalities. The same amount of time was spent on the verbal description of the same action in the auditory condition. The total presentation time was around 3 min across all modalities. 2.3. Procedure Similar to misinformation studies conducted earlier (Loftus, Miller, & Burns, 1978), the experiment consisted of three phases: 1) presentation of stimuli; 2) presentation of misleading information; and 3) a multiple choice test containing correct and misleading answers. Immediately after participants listened to, watched, and/or acted out the series of events, they read a written account of the same events on the computer screen. Misleading information was incorporated into the written account of events (misinformation condition) or not (control condition).3 Appendix A shows an example. After the filler task, that took about 20 min to complete to allow for consolidation of the misinformation, participants answered 20 questions on a multiple choice test. Sixteen questions contained one correct and two incorrect alternatives that did not reflect any misleading information. The correct recognition score was computed on these questions. Four questions were biased by misleading information from the script. Misinformation acceptance was scored as the number of misinformation-containing answers chosen for the total number of misinformation-containing questions. There were four versions of the recognition task with questions being presented in different orders. The questions containing misleading answers were never at the very beginning or end of the questionnaire nor were they close to other questions with misleading 1 The experiment was combined with two other experiments. Therefore, participants who conducted the study in one experiment could potentially be part of the experiment again when participating in another experiment. None of the participants reported prior participation. 2 The addition of an auditory condition with enactment was considered but not implemented because piloting revealed that it was too difficult for participants to enact the scenes without visual input. In the vision condition, participants imitated the action performed by the person on the slide. 3 An reading modality for the presentation of misinformation and control condition was chosen in order to avoid overlap with the auditory encoding condition.
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63
answers. Errors were scored as the number of incorrect (but not misleading) alternatives chosen from the questions containing misleading answers. They could only be calculated for questions containing misleading answers because for the other questions, no misleading answers were involved, hence participants could not be confused by a misleading answer. Appendix B displays examples of these questions and answers. At the end of the experiment, participants filled in two questionnaires, the CEV (Creatieve Ervaringen Vragenlijst — Creative Experiences Questionnaire, Merckelbach, Muris, Rassin, & Horselenberg, 2000, Cronbach's α = 0.79) and the DES (Dissociative Experiences Scale, Boon & Draijer, 1995). The CEV consists of 25 questions that assess one's proneness to fantasy/imagination. Participants with high scores can easily imagine situations that are not real. About 10% of the population has high scores on this measure and in some studies, it has been found to correlate positively with false memory acceptance (Merckelbach et al., 2000). The DES contains 28 questions on dissociative symptoms, such as memory distortion and depersonalization. Individuals with high scores tend to be more susceptible to misinformation acceptance (Merckelbach et al., 2000, Cronbach's α = 0.89). These measures were included to assess whether they would correlate with misinformation acceptance. To assess the role of modality in correct recognition and misinformation acceptance over time, participants were asked to answer the same questions two weeks later (presented in a different order) in a surprise recognition test. If the enactment effect can be demonstrated under these conditions, an effect over a delay would also demonstrate consolidation of the effect. Earlier research demonstrated longerterm benefits of an enactment effect over a period of two weeks in free recall over verbal and visual conditions (Dijkstra et al., 2008). Predictions based on a motor encoding view were that the enactment condition would yield better recognition memory than the auditory and visual condition, definitely for correct recognition of items based on unaltered information (standard motor encoding view), and possibly also for lower misinformation acceptance for answers to items that reflected misleading information (strong motor encoding view). Motor encoding of events involves processing of distinct actions which makes them easier to recognize later whereas verbal and visual encoding allows relational encoding which could impede recognition of specific events. The episodic integration view would not predict an enactment advantage for immediate or delayed recognition memory, correct memory or misinformation acceptance, because strategic processing would not be possible in the current experimental set-up. Participants enacted a sequence of events that was already presented visually and therefore did not involve any planning of actions.
16
immediate
12 10 8 6 4 2 0
visual
auditory
enactment
Fig. 1. Number of items recognized correctly among all participants across modalities and retention interval. Error bars represent standard error.
conditions. Subsequent comparisons specifically showed better immediate, t(73)= 2.86, p b .01, and delayed memory, t(74) = 4.51, p b .001, in the enactment than in the visual condition. The same was shown for enactment relative to the auditory condition, for immediate, t(54) = 2.15, pb .05, and delayed memory, t(47)= 4.11, p b .001 There was no difference in immediate or delayed memory between the auditory and visual conditions (tb 1). The second hypothesis dealt with the role of modality in misinformation acceptance and predicted lower misinformation acceptance in immediate and delayed retrieval tasks and fewer errors in the enactment condition. To test this hypothesis, two repeated measures ANOVAS were conducted on all participants who completed the immediate and delayed recognition test. Both analyses were conducted on performance on misinformation containing questions. The first analysis involved the scores of misinformation acceptance, the second analysis included only the errors made on these questions (i.e. choice for the incorrect but not misinformation containing answer). Fig. 2 presents the results with regard to misinformation acceptance. A mixed analysis of variance showed a main effect of time interval, F(1, 101) = 4.17, p b .05, η 2 = .040, a main effect of misinformation manipulation, F(1, 101) = 62.25, p b .001, η 2 = .381, and a marginal three-way interaction of interval by condition by manipulation, F(1, 101) = 2.50, p = .087, η 2 = .049. Because an enactment benefit was predicted specifically with regard to the misinformation condition, a separate analysis was conducted among a subset of participants
3. Results
4
# items accepted
immediate
The design was a 3 (modality: auditory, visual or enactment) by 2 (misinformation versus no misinformation) by 2 (retention: immediate versus delayed) mixed design with modality and misinformation as between subjects factors and retention interval as within subjects factor. The first hypothesis addressed the role of modality on correct memory of stimuli materials over time. To test this hypothesis a repeated measures ANOVA was conducted on all participants who completed the immediate and delayed recognition test for unaltered information. Fig. 1 presents the results. A mixed ANOVA with factors of condition (auditory, visual, enactment), manipulation (misinformation, control), and retention interval (immediate, delayed) showed a main effect of retention interval, F(1, 102) = 60.07, p b .001, η 2 = .373, a main effect of condition, F(2, 101) = 10.33, p b .01, η2 = .170, and a condition by time interval interaction, F(2, 101) = 5.25, p b .01, η2 = .094, on memory of items without misleading answers. Tukey post-hoc tests indicated differences between the enactment and visual condition and auditory
delayed
14
# items
60
delayed
3
2
1
0 auditory
visual
enactment
Fig. 2. Number of answers accepted containing misinformation by participants exposed to misinformation across modalities and retention interval. Error bars represent standard error.
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63
who received misleading information. This mixed analysis of variance showed no main effect of condition or retention interval but a condition by retention interval interaction, F(2, 54) = 3.22, p b .05, η 2 = .107, on misinformation acceptance. Misinformation acceptance was lowest initially in the auditory condition relative to the visual, t(30) = 2.89, p b .01, and enactment condition, t(40) = 2.07, p b .05, but increased significantly from immediate to delayed retrieval in the auditory condition, t(16) = 2.50, p b .05. There were no differences between conditions for delayed retrieval, nor were there other changes in misinformation acceptance over time for the visual and enactment condition. To assess if the misinformation confused participants to the extent that they chose an answer that was neither correct nor the answer containing misinformation, additional analyses were conducted to assess the role of modality on errors as those answers could reflect source attribution errors. An ANOVA on errors in the misinformation condition demonstrated no condition by retention interval interaction nor a main effect of retention interval but a main effect of condition, F(2, 55) = 3.60, p b .05, η 2 = .116. Only the visual and enactment conditions differed here, with fewer errors in the enactment than visual condition for immediate and delayed error performance, t(39) = 2.17, p b .05, and t(39) = 2.27, p b .05. To test long-term effects of modality on correct recall and misinformation acceptance, a different group of 59 participants was exposed to the same manipulation as described above with the exception that no immediate recognition test was given, only a delayed recognition test. A one-way ANOVA on correct recognition showed a main effect of condition, F(2, 56) = 4.73, p b .05. Tukey post-hoc comparisons indicated differences between the enactment and auditory conditions. Subsequent comparisons showed higher performance on recognition of unaltered items under conditions of enactment relative to auditory encoding., t(37) = 2.64, p b .05. There was no effect of condition on misinformation acceptance after a delay. The pattern was similar to that of the results described earlier although the samples differed in performance on recognition of unaltered information with an advantage of the sample being exposed to a pretest, t(165) = 5.21. Finally, to test very long-term effects of modality on correct recall and misinformation acceptance, participants were contacted after a year to answer the same questions as for immediate and delayed recall. Only a subset of these participants responded (27), which means that these data must be interpreted with caution. Nevertheless, a mixed ANOVA with factors of condition (auditory, visual, enactment), manipulation (misinformation, control), and retention interval (immediate, short delay, long delay) showed a main effect of interval, multivariate 16
auditory
visual
61
F(2, 42) = 22.70, p b .001, η2 = .760, and condition, F(2, 21) = 3.937, p b .05, η2 = .275, and a three-way interaction of condition by misinformation manipulation by retention interval, F(2, 85) = 2.85, p b .05, η2 = .213. The results are presented in Fig. 3. Subsequent analyses were conducted to describe the pattern of results. Recognition memory decreased over time, from immediate recognition to the year-delay, t(26) = 8.46, p b .001, and from two-week delay recognition to the year delay, t(26)= 7.32, p b .001. A post-hoc test for condition indicated differences between the auditory and enactment conditions. This pattern was modulated by the misinformation manipulation. For the auditory condition, differences in recognition memory from immediate or two-week delay to one year delay only occurred for participants who were not exposed to misinformation, whereas those differences always occurred for the enactment condition. A mixed analysis of variance on misinformation acceptance with the three time intervals only showed a main effect of manipulation, F(1, 21) = 10.46, p b .01, η 2 = .333 with higher misinformation acceptance in the misleading condition (M = .38, SE = .036) than in the control condition (M = .19, SE = .036). To assess whether misinformation acceptance or errors correlated with proneness to fantasy or dissociative experiences, bivariate correlation analyses were conducted with these measures and misinformation acceptance and error scores. There were significant correlations between CEV and DES scores, r(50) = .330, p b .05 and between errors in immediate retrieval, r(53) = .297, p b .05. Proneness to fantasy may contribute to confusion regarding the correct answer for questions containing misleading answers. 4. Discussion We examined the role of encoding modality in correct recognition of questions containing no misleading answers, misinformation acceptance, and errors. The strong version of the motor encoding view predicted an enactment advantage for recognition on each of these measures, whereas the standard version of this view predicted an enactment advantage only for recognition for unaltered information. The results with regard to memory for unaltered information supported the standard version of the motor encoding view. The modality by retention interval interaction showed a distinct advantage of the enactment modality as expected, both in immediate and delayed recognition relative to the auditory and visual conditions. In other words, participants who had acted out the events they observed on the slides had better immediate and delayed recognition than participants who had only watched the events or listened to an auditory
enactment
14 12
# items
10 8 6 4 2 0 immediate
two-week
one year
no misinformation
immediate
two-week
one year
misinformation
Fig. 3. Number of items recognized correctly among all participants who responded after a year across modalities, misinformation conditions, and retention interval. Error bars represent standard error.
62
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63
version of the events. Although recognition performance generally deteriorated over time, recognition under enactment was spared over time compared to the other conditions. An additional analysis to assess performance with a different group of participants who did not get an immediate recognition task revealed better memory performance under enactment than auditory encoding conditions. This also supports the standard encoding view. An enactment benefit is still present when the recognition test is administered for the first time after two weeks instead of after the filler task during the same session as when (misleading) post-event information is presented. Longer term effects of encoding, after one year, were assessed as well with a subset of the original group of participants. The results showed a three-way interaction of the relevant variables, suggesting an overall pattern of forgetting that can be expected, but also a reduction of the enactment benefit in the misinformation condition. Although the results need to be interpreted with caution because of the small sample size, it is reasonable to assume that to some extent, confusion caused by misinformation led to a certain level of contamination of answers to questions that never contained any misleading answers. Future research could resolve this issue. The enactment advantage is consistent with results of other studies that demonstrated a benefit of enactment in immediate and delayed recall in comparison with a visual modality (Dijkstra et al., 2008). These studies have demonstrated benefits of enactment over verbal encoding in immediate and delayed recall over a week (Manzi & Nigro, 2008) or cued recall after a two week retention period (Dijkstra et al., 2008). They are also consistent with research showing better recall with non-literal enactment compared to standard verbal learning (Noice & Noice, 2007). No other studies have compared as of yet an auditory modality with a visual and enactment modality for recognition performance of an event sequence with related events. The rather small decline in recognition over time in the enactment modality demonstrates that enactment is not just a benefit of encoding but goes beyond that. This finding is consistent with a nonstrategic explanation of the enactment effect that emphasizes the enhanced item-specific processing and facilitation due to motor encoding during enactment. It is not consistent with an episodic integration view because selfinvolvement and strategic processing were not possible under these experimental conditions. Participants imitated what they saw and therefore could not plan their own actions. This means that any facilitation of encoding for performance was due to enactment. This is an important finding as it illustrates that motor encoding is a reliable, robust effect even when stimuli materials are action sequences. Moreover, it is an effect that holds over a time period of two weeks (but not one year) and without an immediate testing condition. The second prediction tested the strong version of the motor encoding view, a reduction of misinformation acceptance under conditions of enactment. This hypothesis was only partially supported. For immediate recognition, the results indicated a lower rate of misinformation acceptance in the auditory instead of the enactment condition. Even though misinformation acceptance increased significantly in the auditory condition over time, and although errors were lower for delayed recognition performance in the enactment condition, the expected enactment advantage was absent. How can we explain this unexpected role of an auditory modality advantage and a lack of enactment benefit to reduce misinformation acceptance? A possible explanation for this result is modality congruity. A modality congruity of matching encoding and retrieval modalities could facilitate performance and overrule benefits of other modalities. Results of a recent study showed lower false memory acceptance under modality congruent retrieval conditions, oral recall of auditorily presented stimuli (Rummer, Schweppe, & Martin, 2009). Although there was no exact modality match in the current study because the encoding modality was auditory and the script (with or
without misinformation) and recognition test were written, encoding and retrieval conditions were nevertheless closer in modality (a verbal modality) than the visual and enactment encoding conditions. The auditory account of the event sequence likely resulted in the creation of a situation model (a mental representation of the state of affairs of the events) that is normally established after reading or listening to a narrative (Zwaan, 1996). Comparing this representation with a written account of this sequence would reveal inconsistencies with the original information more easily than when modality-different representations are compared. This representation may be most coherent shortly after its formation, and consequently, not be as reliable for comparison after a time period of two weeks. Discrepancies between the original representation based on the auditory account and delayed recognition test should be less noticeable then and this is supported by the data that no longer show a benefit of auditory encoding after the retention period of two weeks. Our conclusion has to be that the strong version of the enactment hypothesis cannot be maintained in the context of a misinformation paradigm. Motor encoding does not provide protection against misinformation acceptance in comparison to encoding modalities that globally match in encoding and retrieval. Future studies should therefore test how the enactment advantage will hold up in a design for which the encoding modalities and modality in which post-event information is presented are entirely different. This study has presented further evidence for the motor encoding view by demonstrating benefits of enactment in immediate and delayed retrieval for unaltered information that cannot be attributed to other elements in the encoding process. A contribution to the field of research is that the enactment benefit has been demonstrated with naturalistic stimulus materials: an action sequence of related events. A possible application of these findings could be to implement an enactment component in more everyday tasks for which recall or recognition of action sequences are required. A suitable domain to implement enactment as part of the learning process is an educational setting. The long term benefits of enactment, demonstrated in this study, should be particularly beneficial for long term retention. Acknowledgments Funding for this study was provided by a Toptalent grant from the Department of Social Sciences at the Erasmus University of Rotterdam. The author wishes to acknowledge the help of Shima Kia, Sander Lambellais, Eelco Moerman, Nynke van Oostrom, Lysanne Post, and Michel Quak in the data collection. Appendix A. Supplementary data Supplementary data to this article can be found online at doi:10. 1016/j.actpsy.2012.02.003. References Ayers, M. S., & Reder, L. M. (1998). A theoretical review of the misinformation effect: predictions from an activation-based memory model. Psychonomic Bulletin & Review, 5, 1–21. Bäckman, L. (1985). Further evidence for the lack of adult age differences on free recall of subject-performed tasks: The importance of motor action. Human Learning, 4, 79–87. Bäckman, L., & Nilsson, L. -G. (1985). Prerequisites for the lack of age differences in memory performance. Experimental Aging Research, 11, 67–73. Barsalou, L. W. (2008). Grounded cognition. Annual Review of Psychology, 59, 617–645. Boon, S., & Draijer, N. (1995). Screening en diagnostiek van dissociatieve stoornissen. Lisse: Swets & Zeitlinger. Cohen, R. L. (1983). The effect of encoding variables on the free recall of words and action events. Memory & Cognition, 12, 633–641. Cohen, R. L., & Stewart, M. (1982). How to avoid developmental effects in free-recall? Scandinavian Journal of Psychology, 24, 9–15. Dijkstra, K., MacMahon, C., & Misirlisoy, M. (2008). The effects of golf expertise and presentation modality on memory for golf and everyday items. Acta Psychologica, 128, 298–303.
K. Dijkstra, E.M. Moerman / Acta Psychologica 140 (2012) 58–63 Engelkamp, J., & Cohen, R. L. (1991). Current issues in memory of action events. Psychological Research, 53, 175–182. Engelkamp, J., Zimmer, H. D., & Denis, M. (1989). Paired-associate learning of action verbs with visual-imagined or motor-imaginal encoding instructions. Psychological Research, 50, 257–263. Engelkamp, J., Zimmer, H. D., Mohr, G., & Sellen, O. (1994). Memory of self-performed tasks — Self performing during recognition. Memory & Cognition, 22, 34–39. Knopf, M., Mack, W., Lenel, A., & Ferrante, S. (2005). Memory for action events: Findings in neurological patients. Scandinavian Journal of Psychology, 46, 11–19. Koriat, A., Ben-Zur, H., & Druch, A. (1991). The contextualization of input and output events in memory. Psychological Research, 53, 260–270. Kormi-Nouri, R. (1995). The nature of memory for action events: An episodic integration view. European Journal of Cognitive Psychology, 11, 337–363. Kormi-Nouri, R. (2000). The role of movement and object in action memory: A comparative study between blind, blindfolded and sighted subjects. Scandinavian Journal of Psychology, 41, 71–75. Lindsay, D. S., & Johnson, M. K. (1989). The eyewitness suggestibility effect and memory for source. Memory & Cognition, 17, 349–358. Loftus, E. F. (2005). A 30-year investigation of the malleability of memory. Learning and Memory, 12, 361–366. Loftus, E. F., Miller, D. G., & Burns, H. J. (1978). Semantic integration of verbal information into a visual memory. Journal of Experimental Psychology: Human Learning and Memory, 4, 19–31. Manzi, A., & Nigro, G. (2008). Long-term memory for performed and observed actions: Retrieval awareness and source monitoring. Memory, 16, 595–603. Masumoto, K., Takai, T., Tsuneto, S., & Kashiwagi, T. (2004). Influence of motoric encoding on forgetting function on memory for action sentences in patients with Alzheimer's disease. Perceptual and Motor Skills, 98, 299–306.
63
Merckelbach, H., Muris, P., Rassin, E., & Horselenberg, R. (2000). Dissociative experiences and interrogative suggestibility in college students. Personality and Individual Differences, 293, 1133–1140. Nilsson, L. G., & Bäckman, L. (1991). Encoding dimensions of subject-performed tasks. Psychological Research, 53, 212–218. Nilsson, L. G., Nyberg, L., Klingberg, T., Aberg, C., Persson, J., & Roland, P. E. (2000). Activity in motor areas while remembering action events. NeuroReport, 11, 2199–2201. Noice, H., & Noice, T. (2007). The non-literal enactment effect. Filling in the blanks. Discourse Processes, 44, 73–89. Nyberg, G., Nilsson, L. G., & Bäckman, L. (1991). A component analysis of action events. Psychological Research, 53, 219–225. Nyberg, L., Petersson, K. M., Nilsson, L. G., Sandblom, J., Aberg, C., & Ingvar, M. (2001). Reactivation of motor brain areas during explicit memory for actions. NeuroImage, 14, 521–528. Rummer, R., Schweppe, J., & Martin, R. C. (2009). A modality congruency effect in verbal false memory. European Journal of Cognitive Psychology, 21, 473–483. Spranger, T., Schatz, T. R., & Knopf, M. (2008). Does action make you faster? A retrievalbased approach to investigating the origins of the enactment effect. Scandinavian Journal of Psychology, 49, 487–495. von Essen, J. D., & Nilsson, L. -G. (2003). Memory effects of motor activation in subjectperformed tasks and sign language. Psychonomic Bulletin & Review, 10, 445–449. Worthen, J. B., & Wood, V. V. (2001). Memory discrimination for self-performed and imagined acts: Bizarreness effects in false recognition. The Quarterly Journal of Experimental Psychology, 54, 49–67. Zimmer, H. D., & Engelkamp, J. (1985). An attempt to distinguish between kinematic and motor memory components. Acta Psychologica, 58, 81–106. Zwaan, R. A. (1996). Processing narrative time shifts. Journal of Experimental Psychology: Learning, Memory, and Cognition, 22, 1196–1207.