Unconscious Plagiarism in Recall: Attribution to the Self, but not for Self-Relevant Reasons Research Reports Unconscious Plagiarism in Recall: Attribution to the Self, but not for Self-Relevant Reasons Timothy J. Perfect*a, Louisa-Jayne Starka a University of Plymouth, Plymouth, UK. Abstract Previous research has shown that if people improve other’s ideas, they subsequently unconsciously plagiarise them at a dramatically higher rate than if they imagine them, or simply hear them again. It has been claimed that this occurs because improvement resembles the process of generation, and that these are confused during retrieval. However, an alternate possibility is tested here: plagiarism may increases because improvement increases personal relevance of the ideas. Two studies were conducted in which there was an initial generation phase, followed by an elaboration phase in which participants imagined the previous ideas, improved them for their own use, or improved them for an older adult’s use. One week later, participants attempted to recall their own ideas, and generated new solutions to the previous problems. In both studies, improvement of doubled the rate of subsequent plagiarism in the recall own task, but this effect was not mediated by whether people improved ideas for their own use, of for use by someone else. Improvement had no effect on plagiarism in the generate-new task. These studies therefore rule out personal relevance, or personal semantics as the source of the improvement effect in unconscious plagiarism. Keywords: source memory, unconscious plagiarism, self Europe's Journal of Psychology, 2012, Vol. 8(2), 275–283, doi:10.5964/ejop.v8i2.459 Received: 2012-03-26. Accepted: 2012-04-13. Published: 2012-05-31. *Corresponding author at: University of Plymouth, Drake Circus, Devon, PL4 8AA, UK, email:tperfect@plymouth.ac.uk. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The creation and ownership of ideas is core to the professional activity of academic researchers in all disciplines. As teachers, we strive to teach our students the importance of citing previous work where appropriate, and as researchers we endeavour to be scrupulous in acknowledging the work that has gone before. However, in order to publish and make a contribution to the literature, we must demonstrate originality in our methods, findings, or ideas. But how do we know if we have been genuinely novel, and that we haven’t failed to acknowledge the work of others? Fortunately, the peer-reviewed publication system offers some protection, and so consequently public disputes about the origin of ideas are rather rare. However, in our experience, private disputes and resentments about the source of an idea are rather more common. It is rare that someone works entirely alone, without discussing ideas with colleagues or students, and even such academic isolates they will have read the work of others or heard talks at conferences. Given the broad literature on source memory errors it is inevitable that there will be occasions on which we are mistaken about the source of our ideas and risk unconsciously plagiarising others. The experimental literature on unconscious plagiarism began with Brown and Murphy (1989), who developed the now-standard three-stage paradigm. Initially, groups of participants take turns to generate solutions to a problem. Subsequently, participants attempt to recall their own solutions, avoiding those generated by others (the recall-own --> Europe's Journal of Psychology ejop.psychopen.eu | 1841-0413 http://creativecommons.org/licenses/by/3.0/ http://creativecommons.org/licenses/by/3.0 http://ejop.psychopen.eu/ http://ejop.psychopen.eu/ http://www.psychopen.eu/ task). Finally, participants attempt to generate new solutions avoiding those mentioned in the first session (the generate-new task). In both tasks, Brown and Murphy (1989) reported significant rates of plagiarism. That is, when attempting to recall their own ideas people recalled the ideas of others, and when generating new ideas they plagiarised old ideas, including their own. Subsequent research has explored many of the factors that exacerbate or mitigate the magnitude of these plagiarism errors. However, rather than review that literature here we refer the interested reader to a recent review (Perfect & Stark, 2008a). Instead, we focus here on one finding that has emerged from this literature – the idea-improvement effect. In a series of studies, we have investigated the impact of different forms of elaboration of ideas during the retention interval between the initial idea generation and the subsequent recall-own and generate-new tests (Perfect, Field, & Jones, 2009; Perfect & Stark, 2008b; Stark, Perfect, & Newstead, 2005; Stark & Perfect, 2006, 2007, 2008). Our rationale for investigating the impact of thinking about the ideas during the retention interval was that real-world cases of plagiarism are unlikely to have resulted from a single exposure to an idea, without the accused having given considerable thought to the development of the idea under dispute. In our studies we have contrasted two forms of idea elaboration: idea imagery, which requires participants to form mental images of the ideas, and idea-improvement which requires participants to improve the ideas that they heard previously. Across many studies, the results have been remarkably consistent. Compared to control, both forms of elaboration improve correct recall equally, whilst neither affects the rate of plagiarism on the generate-new task. Idea imagery also has no impact upon the rate of plagiarism on the recall-own task. However, idea-improvement dramatically increases rates of plagiarism in the recall-own task. In absolute terms, improving ideas once can result in three times the base rate level of plagiarism (e.g. Stark et al., 2005) whilst improving ideas twice can result in up to 13 times the number of plagiarised ideas (Stark & Perfect, 2008). This idea-improvement effect survives financial inducement to avoid plagiarism (Stark, Perfect, & Newstead, 2005), and the use of a source-monitoring test in place of a recall test (Stark & Perfect, 2007). It is also magnified by increasing the delay between idea generation and final test (Stark & Perfect, 2007). In contrast, neither repetition, nor delay impact upon the rate of plagiarism following imagery (Stark & Perfect, 2007, 2008). We have sought to explain the differential effect of imagery and idea-improvement on plagiarism rates in terms of the source-monitoring framework (Johnson, Hashtroudi, & Lindsay, 1993). We have argued that improving ideas requires a process of generation, similar to the original phase of idea generation itself. Thus, when participants try to recall an original idea they may rely on records of generative processes as a cue to source, and so confuse original ideas with improved ideas. In contrast, imagery elaboration creates records of visual (or other sensory) records, which are readily distinguished from originally generated ideas. However, both generative processes, and imagery processes are cues to oldness, and so both forms of idea elaboration are equally useful cues in the generate-new task, where the focus is on avoiding familiar responses. Thus, we have argued that a source monitoring account can explain the differential outcomes of the two forms of elaboration across the recall-own and generate-new tasks. Whilst we have favoured a process-oriented account of the idea-improvement effect, we also acknowledge that improvement and imagery result in very different ideas. Imagining an idea does not alter the fundamental nature of the idea itself: it merely changes a verbal proposition into a visual image. However, improving an idea alters the nature of the proposition itself. Thus, one possibility is that people plagiarise not because of the process applied to those ideas, but because the content of those ideas has changed. Europe's Journal of Psychology 2012, Vol. 8(2), 275–283 doi:10.5964/ejop.v8i2.459 Unconscious Plagiarism in Recall 276 http://www.psychopen.eu/ We have previously tried to address the issue of memory content in two ways, and we introduce a third in the present work. The first such attempt looked at whether it was the amount of information about an idea that was the cause of plagiarism. In all our earlier studies, participants generated 3 improvements to an idea. Thus, improved ideas were considerably richer in detail than unimproved ideas, and thus we reasoned that it might be this richness that led to plagiarism in the recall-own task. We explored this issue by having participants imagine ideas that had been improved by someone else (Stark & Perfect, 2006). In this manner, the content of improved and imagined ideas was matched. However, there was no evidence that imagining these already-improved ideas led to plagiarism at any greater rate than control items that were neither imagined nor improved in the interval. Another possibility is that it is not the richness of the ideas that causes plagiarism, but rather the valence, or quality. If participants are genuine in their attempts to improve the ideas then perhaps they later plagiarise those ideas because the ideas are somehow better. Perfect and Stark (2008b) explored this possibility. Participants generated ideas in the standard manner. However, prior to the elaboration phase, participants were led to believe that their ideas had been evaluated by a panel of judges. They were told that some ideas were judged excellent, and required no further elaboration. Other ideas, judged very good required one improvement, whilst ideas judged merely good required three improvements. Finally, ideas judged to be satisfactory did not merit further improvement. In fact, the assignment of the original ideas to these ratings was entirely arbitrary. Thus, in this design we manipulated both the perceived quality of the ideas and the amount of improvement they received. What we found was that for recall-own plagiarism the number of improvements predicted the rate of plagiarism, whilst rated quality of the ideas had no impact. This was not because the rated quality of the ideas had no impact. For the generate-new task, plagiarism was influenced by rated quality but not by number of improvements. This pattern was replicated by Perfect, Field, and Jones (2009). They had participants generate ideas with a partner who was an expert or a novice in the topic under discussion. In fact, the partner was a confederate who generated identical ideas whatever their putative expertise. Subsequently, there was an improvement phase for half the ideas, before participants recalled their own ideas, or generated new ones. Source credibility had no impact upon plagiarism in the recall-own task, but was associated with generate-new plagiarism. Conversely, improvement had no impact on generate-new plagiarism, but increased recall-own plagiarism. Thus, the pattern across these studies, with respect to the idea-improvement effect on recall-own plagiarism is that it is not caused by the perceived quality of the ideas. Here we focus on a third potential outcome of idea-improvement, namely self-relevance. One possibility is that when asked to improve an idea, participants make improvements that they would wish, in order to fit their own aesthetic sense or personal semantics. Imagine a participant asked to improve the idea of using a brick as a doorstop. They might think that the brick could be carved, painted, and mounted on cork to prevent scratching the floor. But what shape would they mentally carve it, what colour would they mentally paint it and where would they mentally place it? It is plausible that participants might imagine a brick-doorstop in their own home, and improve it to fit their own taste or decor. Later, when they attempt to recall the original ideas, thinking of the doorstop in the context of their home, with personally relevant details, might lead them to erroneously conclude that the idea must have been their own. Thus, it may not be the process of improvement that leads to plagiarism, but the self-relevance of the outcome. We present two studies investigating the role of self-relevance in unconscious plagiarism. Experiment 1 utilises the same task at generation as we have used in the majority of our previous work, namely the Alternate Uses Europe's Journal of Psychology 2012, Vol. 8(2), 275–283 doi:10.5964/ejop.v8i2.459 Perfect & Stark 277 http://www.psychopen.eu/ Test (Christensen, Guilford, Merrifield, & Wilson, 1960). This task requires participants to generate alternate uses for common objects such as a shoe, a paperclip or a brick. Experiment 2 replaced the Alternate Uses Test with a more real-world task based on the lives of our undergraduate participants, but was in all other respects identical to the first experiment, and so we report them together. The use of real-world problem solving tasks has successfully generated unconscious plagiarism in a number of studies (Marsh, Landau, & Hicks, 1997; Perfect, Field, & Jones, 2009; Perfect, Defeldre, Elliman, & Dehon, 2011). In both experiments, participants were asked to generate ways of improving the ideas either for themselves, or an older adult. The aim of each study was to determine whether the idea-improvement effect is the result of the process of generation of improvements to ideas, or occurs because improved ideas are more self-relevant to the participants. A difficulty in testing this hypothesis is that we cannot know what aspects of the idea are under consideration when a person improves an idea, or when they mistakenly recall the idea as their own. For this reason, we rejected use of self-report scales to determine the self-relevance of improved or imagined ideas. Instead we altered the nature of the improvement instructions to focus on either self-relevant improvement, or other-relevant improvement. In the self-improvement instructions, we asked participants to improve the ideas presented to them so that they were more likely to use the idea in their lives. In the other-relevant instructions, we asked participants to improve the idea for everyday use by an older adult. We chose this group as the “other” category because it is a well-understood category, but not one we thought our younger participants would identify with. The effects of these two forms of idea-improvement (self-relevant and other-relevant) were contrasted with idea imagery and a no-elaboration control condition, as in our previous studies. Our expectation was that we would replicate the idea-improvement effect, and that the extent to which plagiarism of ideas subject to self- and other-relevant improvement differ would reflect the role played by self-relevance in the effect. Method Participants Experiment 1: Thirty undergraduate students were tested for the idea generation phase. However, 3 participants failed to attend the second testing session and so only 27 participants completed the experiment. Experiment 2: Thirty-two undergraduate students were tested the initial generation phase. However, three participants failed to attend the second testing session and so only 29 participants completed the experiment. Additionally, 1 participant failed to complete the generate-new phase in the second session, and so data for only 28 participants were analysed for that task. For both experiments, participants were undergraduates from the University of Plymouth and participated either to achieve partial fulfilment of a course requirement or for payment of £8. Procedure Experiment 1: Participants were tested in groups of 4. Members of each group were told they would be presented with object names, and they would have to think of novel uses for those items. As an example, they were told that they might hear an object like a newspaper, and a novel use might be making it into a fan. The experimenter then read out the first object name (brick, shoe, paper-clip or button depending upon counterbalancing condition), and participants were instructed individually by the experimenter to generate an idea for the group to hear. The order that participants were asked for their idea was randomised, such that participants did not know when they would have to speak. Participants were told to listen to the ideas from the group, to avoid repeating previous ideas. Once Europe's Journal of Psychology 2012, Vol. 8(2), 275–283 doi:10.5964/ejop.v8i2.459 Unconscious Plagiarism in Recall 278 http://www.psychopen.eu/ each participant had provided an idea, participants were asked for their next idea, again in randomised order. This process was repeated until each participant had generated 4 ideas for each of the 4 objects. The elaboration phase immediately followed the generation phase. Of the previously generated ideas, a quarter (one idea from each participant, from each category) was then subject to the following condition treatments. For the self-relevant idea-improvements participants had to write down 3 ways that the ideas could be improved such that they would be more likely to use the idea in their own lives. For the other-relevant idea-improvements participants had to write down 3 ways that the ideas could be improved such that an older adult (65 years or older) would be more likely to use the idea in their daily lives. For imagery items, participants rated how easy it was to imagine the idea, and how effective that idea would be. Control ideas were not re-presented at this stage. The order that participants performed these tasks was counterbalanced. This task completed the first session, which lasted approximately 60 minutes. One week later, participants returned as a group to complete the recall-own and generate-new tasks, in that order. In the recall-own phase, participants were given a response sheet with the 4 object name cues on, with 4 blank spaces under each. Participants were asked to recall their own ideas for each object that they had generated during the first session. They were instructed not to guess, and that they could leave blank spaces if they could not remember all their ideas. Immediately following the recall task, participants were given a second response sheet, with the same object name cues, again with 4 blank spaces under each. For this task, participants were asked to generate 4 new ideas for each object, with instructions not to use any of the ideas from the previous session, from any of the objects. For this task, participants were required to generate 4 ideas. Experiment 2: The procedure was identical to Experiment 1, except that the Alternate Uses Task was replaced with a task of generating ideas to enhance: 1) their University course, 2) their University’s facilities, 3) The city centre and 4) their student life. Participants were presented with the first topic and instructed one at a time to share their idea with the group. During the elaboration phase, we replaced the term “older adult” with “mature student aged over 65”, to ensure the relevance of the improvement task to older adults. Results In each study, there were three dependent measures: level of correct recall of own ideas, plagiarism of other’s ideas in the recall-own task, and plagiarism of ideas in the generate-new task. Inspection of the data for these measures in Table 1 reveals the standard pattern we have reported previously for both experiments. For recall, all forms of elaboration improved correct responding relative to control. For the generate-new task, there was an overall effect of elaboration on plagiarism, with control ideas plagiarised more often than other ideas, which did not differ. However, for the recall-own task, plagiarism was inflated following idea-improvement, as in our previous studies. Below we report the statistical analyses for both experiments. Correct Recall Experiment 1: A within-subjects ANOVA a significant main effect of elaboration status F(3,78)=11.52, p<.001, MSE = 9.52. Sidak-adjusted tests for multiple comparisons revealed that ideas that were subject to any type of elaboration (imagery, self- or other-relevant improvement) were recalled at a significantly higher rate than control, but the different forms of elaboration did not differ from one another. Europe's Journal of Psychology 2012, Vol. 8(2), 275–283 doi:10.5964/ejop.v8i2.459 Perfect & Stark 279 http://www.psychopen.eu/ Table 1. Mean rates of correct recall and plagiarism within the recall-own (RO) & generate-new (GN) phases for control ideas, ideas that were subject to imagery-elaboration, self-relevant and other-relevant elaboration. Elaboration Status Other-relevant improvementSelf-relevant improvementImageryControl SDMeanSDMeanSDMeanSDMean Experiment 1 .882.371.112.37.962.81.891.41Recall 1.261.351.551.37.71.50.53.26UP (RO) .87.73.57.38.76.54.951.23UP (GN) Experiment 2 1.072.281.212.241.052.381.231.69Recall 1.351.591.591.59.77.66.86.62UP (RO) .63.43.58.54.63.39.74.57UP (GN) Notes: UP (RO) = unconscious plagiarism during the recall-own task. UP (GN) = unconscious plagiarism during the generate new task. Experiment 2: Ideas that were subject to elaboration of any kind to any (imagery, self- or other-relevant improvement) were recalled at a numerically higher rate than control but a within-subjects ANOVA revealed that this difference did not reach statistical significance F(3,84)=2.12, p=.10, MSE 2.79. Unconscious Plagiarism in the Recall-Own Task In this task, participants were required to remember as many of their own initial ideas as possible, but recall was not forced. Unconscious plagiarism occurred when participants recalled someone else’s idea as their own. A plagiarised idea was only counted once. Experiment 1: A within subjects ANOVA revealed that there was a significant main effect of elaboration status on plagiarism in the recall-own task, F(3, 78)=9.40, p<.001, MSE = 9.25. Sidak-adjusted multiple comparisons across conditions were revealed that the rate of plagiarism following self- or other-relevant improvements ideas did not differ, but both exceeded the rate seen in the imagery and control conditions, which did not differ. Experiment 2: A within subjects ANOVA of plagiarism errors in the recall task revealed that there was a significant main effect of elaboration status F(3, 84)=6.52, p<.001, MSE = 8.70. Mean plagiarism levels across conditions were compared using Sidak-adjusted multiple comparisons. These revealed that the rate that improved ideas, whether self-or other-relevant, were plagiarised at a greater rate than imagery or control ideas. No other comparison was significant. Unconscious Plagiarism in the Generate-New Task Experiment 1: A within subjects ANOVA was conducted on plagiarism errors in the generate-new task revealed a significant main effect of elaboration status on plagiarism errors F(3,75)=6.19, p<.05 MSE = 3.52. Sidak-adjusted multiple comparisons demonstrated that plagiarism of control ideas significantly exceeded the rate for imagined ideas and other-relevant improved ideas, but not self-relevant improved ideas. There was no evidence of a difference between self-relevant and other-relevant improvement on generate-new plagiarism. Experiment 2: A within-subjects ANOVA revealed that elaboration status did not affect the rate of plagiarised errors, F<1. Europe's Journal of Psychology 2012, Vol. 8(2), 275–283 doi:10.5964/ejop.v8i2.459 Unconscious Plagiarism in Recall 280 http://www.psychopen.eu/ Discussion The results of the experiments were clear, and consistent with previous research. As with previous studies (Perfect, Field, & Jones, 2009; Stark, Perfect, & Newstead, 2005; Stark & Perfect, 2006, 2008) we found evidence of a dissociation between the two forms of elaboration, with respect to the two measures of unconscious plagiarism. Three results were consistent with previous work. Both forms of elaboration increase correct recall, relative to control. They also both numerically reduce plagiarism in the generate-new task relative to control, a trend that is seen in our previous studies, though not always reaching statistical significance. Finally, and most crucially, we found that on the recall-own task, improvement of an idea led to increased plagiarism relative to control, but imagery did not. Across the two studies, as a proportion of ideas output, improvement roughly doubled the rates of plagiarism. For control ideas 15.6% of ideas (Experiment 1) and 26.8% of ideas (Experiment 2) were plagiarised. A similar pattern was observed for imagined ideas (Experiment 1, 15.6%; Experiment 2, 21.7%). These rates increase to 36.6% (Experiment 1) and 41.5% (Experiment 2) of self-relevant improved ideas, and 36.2% (Experiment 1) and 41.1% (Experiment 2) of other-relevant improved ideas. Thus, despite having demonstrated reliable levels of plagiarism in the recall own tasks, we found no evidence that the size of this effect is modified by the self-relevance of the improvements that participants generated. Rates of plagiarism following self- and other-relevant improvements were almost identical, and since recall was matched across conditions, this meant that the proportion of plagiarised ideas was also very similar. Thus, it appears that that self-relevance does not play a causal role in plagiarism in the recall-own task. The studies were also consistent with our earlier work in showing that neither improvement nor imagery increases the propensity to plagiarise in the generate-new task. The lack of an effect on the generate-new task is not unexpected, and fits with a strength-based account of plagiarism errors in the generate-new task (c. f. Marsh & Landau, 1995). At test, when participants try to generate new ideas, old ideas may intrude. If participants recall any form of improvement, whether for their own use, or for an older adults use, then they are likely to use this information to judge an idea as being old, and thus avoid plagiarising it. Our previous explanation of the idea-improvement effect in recall plagiarism has centred on a source-monitoring account, arguing that the process of idea-improvement resembles that used in initial idea generation (Stark, Perfect, & Newstead, 2005: Stark & Perfect, 2006, 2007, 2008). However, the notion of participants using personal relevance as a cue is also compatible with a source-monitoring account: the essence of a source-monitoring account is that memories are multi-dimensional and people weight the evidence from different dimensions to make attributions about source (Johnson, Hashtroudi, & Lindsay, 1993). We believe that there is an account that can simultaneously explain the presence of an idea-improvement effect, and an absence of a self-relevance effect. This pattern would follow if participants made automatic judgements of source based upon the cognitive processes associated with a memory, rather that the content of the memory itself. In particular, we argue that the process of improving ideas, whether for oneself or someone else, requires generative processes, which resemble the original process of generating ideas. Whilst the initial phase of idea generation might not have involved personal relevance, it did involve generation, which is consequently a useful cue to idea ownership at retrieval. However, the use of this cue is compromised by the presence of the improvement phase, which also associates a process of generation with the ideas, but does so for both own-ideas and ideas from others. From the participant’s perspective, another person’s idea that has been improved will have records of both the perceptual details associated with hearing the idea initially, plus the generative processes associated Europe's Journal of Psychology 2012, Vol. 8(2), 275–283 doi:10.5964/ejop.v8i2.459 Perfect & Stark 281 http://www.psychopen.eu/ with improving it. If the perceptual details are unavailable, or weighted less than the generative processes, participants may erroneously attribute the origin of the idea to themselves. Thus, in summary, we argue that participants when attempting to recall their own ideas make automatic judgements of source, based upon the qualitative aspects of the memory trace, rather than the contents of the memory. Such an account is consistent with the original source-monitoring framework claim that source monitoring is achieved through heuristic processes operating in tandem with systematic processes (Johnson, Hashtroudi, & Lindsay, 1993). In the original framework, systematic checking processes based upon the contents of the memory can be used to verify the output of the heuristic system, but if participants fail to engage in such systematic checking, perhaps because the ongoing tasks demands are too high (Landau, Thomas, Thelen, & Chang, 2002) then errors based upon heuristic judgements will occur. Our argument is that either the checking processes are uninformative in the present context, or participants do not engage in them at all, instead relying on automatic judgements based on generative cues to idea ownership. Although our main focus in this study has been the comparison of self- and other-relevant improvement, it is worth commenting on the relative effects of improvement and imagery across the two studies reported here. As in all our previous demonstrations, improvement increases plagiarism relative to control and imagery. This is despite the fact that imagery increases correct recall to the same degree as improvement, and despite the fact that imagery and improvement have indistinguishable effects on generate-new plagiarism. It is this pattern that we have argued rules out memory strength as an account of why people plagiarise other people’s ideas when they recall. People do not misattribute other’s ideas to themselves because they are associated with a general sense of fluency, familiarity, or oldness. The current data also suggest that they don’t make this mistake because the idea contains details that are personally relevant. Instead, the current data strongly suggest that people misattribute other people’s ideas that they have improved because of the generative nature of the improvement process. Funding This work was funded by the Economic and Social Research Council in the form of a project grant to both authors (R000221647). References Brown, A. S., & Murphy, D. R. (1989). 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Source credibility and idea-improvement have independent effects on unconscious plagiarism errors in recall and generate-new tasks. Journal of Experimental Psychology. Learning, Memory, and Cognition, 35, 267-274. doi:10.1037/a0013936 Perfect, T. J., & Stark, L.-J. (2008a). Tales from the Crypt…omnesia. In J. Dunlosky and R. A. Bjork (Eds.). A handbook of memory and metamemory (pp. 285-314). New York: Psychology Press. Perfect, T. J., & Stark, L.-J. (2008b). Why do I always have the best ideas? The role of idea quality in unconscious plagiarism. Memory (Hove, England), 16, 386-394. doi:10.1080/09658210801946501 Stark, L.-J., & Perfect, T. J. (2006). Elaboration inflation: How your ideas become mine. Applied Cognitive Psychology, 20, 641-648. doi:10.1002/acp.1216 Stark, L.-J., & Perfect, T. J. (2007). Whose idea was that? Source monitoring for idea-ownership following elaboration. Memory (Hove, England), 15, 776-783. doi:10.1080/09658210701643042 Stark, L.-J., & Perfect, T. J. (2008). The effects of repeated elaboration on unconscious plagiarism. Memory & Cognition, 36, 65-73. doi:10.3758/MC.36.1.65 Stark, L.-J., Perfect, T. J., & Newstead, S. (2005). When elaboration leads to appropriation: unconscious plagiarism in a creative task. Memory (Hove, England), 13, 561-573. doi:10.1080/09658210444000232 About the Authors Tim Perfect is Professor of Experimental Psychology and Director of the Centre for Brain, Cognition and Behaviour at the University of Plymouth. Louisa-Jayne Stark was a PhD student and Postdoctoral Researcher at the University of Plymouth, but has now emigrated to Canada, where she is taking a career break to raise a family. Europe's Journal of Psychology 2012, Vol. 8(2), 275–283 doi:10.5964/ejop.v8i2.459 Perfect & Stark 283 http://dx.doi.org/10.1037/0278-7393.23.4.886 http://dx.doi.org/10.1080/09658211.2011.590503 http://dx.doi.org/10.1037/a0013936 http://dx.doi.org/10.1080/09658210801946501 http://dx.doi.org/10.1002/acp.1216 http://dx.doi.org/10.1080/09658210701643042 http://dx.doi.org/10.3758/MC.36.1.65 http://dx.doi.org/10.1080/09658210444000232 http://www.psychopen.eu/ Unconscious Plagiarism in Recall Method Participants Procedure Results Correct Recall Unconscious Plagiarism in the Recall-Own Task Unconscious Plagiarism in the Generate-New Task Discussion Funding References About the Authors