Vulnerability to the Misinformation Effect as a Function of Handedness Consistency
A Master’s Thesis
Stephanie Monroe
Marietta College
A Thesis Submitted to the Faculty of Marietta College Psychology Department in Partial
Fulfillment of the Requirements for the Degree of Master of Arts in Psychology May 2019 Running head: HANDEDNESS AND FALSE MEMORY 1
Vulnerability to the Misinformation Effect as a Function of Handedness Consistency
A Master’s Thesis
Stephanie Monroe
Marietta College
A Thesis Submitted to the Faculty of Marietta College Psychology Department in Partial
Fulfillment of the Requirements for the Degree of Master of Arts in Psychology May 2019
HANDEDNESS AND FALSE MEMORY 2
Vulnerability to the Misinformation Effect as a Function of Handedness Consistency
A Master’s Thesis
Stephanie Monroe
Marietta College
This thesis has been approved for the Master of Arts in Psychology Program by the faculty in the
Department of Psychology at Marietta College.
HANDEDNESS AND FALSE MEMORY 3
Abstract
The current study examined the production of false memory in relation to consistency of handedness. Past research has demonstrated that there are individual differences between left- and right-handed people regarding the accuracy of their memory. Subsequent research has suggested that the differences are likely due to interhemispheric interaction, which is more likely from consistency of handedness (inconsistently handed or consistently handed). The current study examined individual differences in vulnerability to the misinformation effect in relation to consistency of handedness. It was predicted that participants with inconsistent handedness would be less vulnerable to the misinformation effect than participants with consistent handedness. The results of the current study however, suggest that there are no significant differences between consistently and inconsistently handed participants regarding false memory utilizing the misinformation paradigm. Explanations for the results are further described in the discussion section.
HANDEDNESS AND FALSE MEMORY 4
Vulnerability to the Misinformation Effect as a Function of Handedness Consistency
People often believe that their memories are always, or almost always, accurate.
However, a wide array of research has shown otherwise. Memory is malleable in the sense that it can be altered by information received prior to the event (proactive interference), or by information received after the event (retroactive interference) (Loftus & Pickrell, 1995).
Inaccurate or completely fabricated memories that are believed to be both accurate and true are referred to as false memories. As time passes, our memories slowly diminish, and our brains automatically fill in the gaps (Loftus & Pickrell, 1995). New information is easily added to memories, altering our memories and making them inaccurate (Roediger & McDermott, 1995).
Additionally, memory reconstruction occurs when the brain automatically fills in fuzzy areas of a memory, making the memory seem and feel accurate, but is in fact fabricated in some way
(Roediger & McDermott, 1995).
Many researchers have explored the underpinnings of false memories and have applied this phenomenon to a multitude of real-world situations including therapy, interrogation methods, and eyewitness testimony (Loftus & Zanni, 1975). Researchers have also been interested in whether there are specific characteristics or individual differences that affect peoples’ performance on memory tests. For example, research has demonstrated that left-handed people tend to exhibit better memory when taking memory tests than right-handed people
(Cuzzocreo, Yassa, Verduzco, Honeycutt, Scott, & Bassett, 2009). One characteristic that has not been heavily researched is consistency of handedness in relation to memory. Specifically, consistency of handedness goes further than just identifying as left- or right-handed, but how consistently a person uses the same hand across several tasks. The current study examines consistency of handedness (inconsistently and consistently handed) and vulnerability to false
HANDEDNESS AND FALSE MEMORY 5 memory. Specifically, consistency of handedness may be a factor of falling victim to the creation of false memories.
False Memory
Loftus has conducted seminal work in false memory research. Loftus was interested in how information given after witnessing an event can alter memories as well as prompt the creation of entirely new memories. Research has shown that after witnessing an event, any information given afterward creates a post-information effect that can alter memories of that event, leading to false recall (Loftus, Miller, & Burns, 1978). Participants were shown, via slide show, a car accident. After being exposed to a series of slides, the participants were given a set of questions to answer about the event they had just witnessed. Some participants were given misleading information while other participants were given information consistent with what they had just seen (Loftus et al, 1978). For example, in the slideshow, participants saw a red car stop at a stop sign. Some participants had the question, “what color was the car that stopped at the stop sign?” while other participants had the question, “what color was the car that waited at the yield sign?” The second group had been presented with the misinformation of the type of sign the car stopped at (Loftus et al, 1978). Participants were most likely to fall victim to the misinformation effect and report false details about the event when misleading information was presented after viewing the event (Loftus et al, 1978). Another experiment explored how the amount of time between the presentation of the stimuli and the recall test affects the accuracy of recall. Overall, the researchers concluded that there are no major differences between immediately, 20 minutes, and one day after, but any timeframe after one day decreases accuracy on the recall test (Loftus et al, 1978).
HANDEDNESS AND FALSE MEMORY 6
Loftus was interested in furthering these findings by inducing complete memories that never happened to the individual, and so conducted the “Lost in a Shopping Mall” study. With the help of family members, Loftus and Pickrell (1995) created believable (but false) memories and had family members “remind” participants of the events (three true events and one fabricated event). The false memory always involved getting lost in a mall or department store. During interviews, participants were asked to recall each of the four memories (the three true memories and one fabricated memory) in as much detail as possible. At the end, they were asked how clear each memory was and how confident they were of the accuracy of each memory (Loftus &
Pickrell, 1995). Overall, by the second interview, confidence levels and clarity for the false memories were relatively high. At the end of the study, the participants were then informed that one of the four memories they were asked to recall was in fact fabricated and they were asked to choose which event was not real. Participants often chose a true event as being false, meaning that they believed the false memory of getting lost in a store was true (Loftus & Pickrell, 1995).
Overall, participants remembered the true events 68% of the time and falsely remembered the fabricated event 29% of the time. This research shows that suggestion and planting information can lead to the formation of memories that never actually happened. When asked how confident each participant was in how accurate their recollection of each event was, participants were relatively confident on all of their memories, including the memory that was unknowingly artificial. This shows that confidence levels are not significantly different between true memories and memories where the misinformation effect has been conducted (Loftus & Pickrell, 1995;
Mahé, Corson, Verrier, & Payoux, 2015; Roediger & McDermott, 1995). This is important because it demonstrates that confidence does not always mean accuracy.
HANDEDNESS AND FALSE MEMORY 7
Roediger and McDermott (1995) have conducted a great deal of research on false memory as well. Roediger and McDermott (1995) developed a recall task that involved being exposed to lists of words by modifying a model originally created by Deese (1959). Each list surrounded one key word that was intentionally left out, called the “critical lure word” (Roediger
& McDermott, 1995). For example, a list would include, “bed, pillow, night, alarm clock, pajamas…” and the critical lure word would be “sleep.” Although the word “sleep” was never presented, participants often falsely remembered seeing or hearing the word, thus creating a false memory. This task is called the Deese-Roediger-McDermott Paradigm, or the DRM Paradigm
(Roediger & McDermott, 1995). Roediger and McDermott’s 1995 research consisted of two experiments. In experiment one, the researchers utilized the DRM task. Participants listened to six lists, all surrounded by one missing critical lure word. Then after a brief break, participants were asked to write down any words they were fairly certain they had heard.
Experiment two was similar, except it involved 16 lists. After the first eight lists, participants took a recall test immediately after. Then after the second set of lists, participants completed math problems for five minutes, followed by a recall test for all 16 lists (Roediger &
McDermott, 1995). The participants also completed a Remember-Know task during the overall recall test (Tulving, 1985). The purpose of the second experiment was to build upon current knowledge and apply Tulving’s Remember-Know task (Roediger, & McDermott, 1995; Tulving,
1985). After being exposed to the DRM Paradigm, participants were exposed to words they had seen before and words they were not previously exposed to. Participants were asked if the words were old (previously exposed) or new (not previously exposed) (Roediger & McDermott, 1995).
Words that were defined as “old” were then further categorized as remembering the word or knowing the word. Participants were asked to label the previously exposed words (old) as
HANDEDNESS AND FALSE MEMORY 8
“remember” if they could mentally picture or remember specifically seeing or hearing the word when they were being exposed to the original lists (Roediger & McDermott, 1995). Participants were also asked to label the old words as “know” if they were confident the word appeared in the original list, but they were unable to access a specific memory of being exposed to it (Roediger
& McDermott, 1995). Both experiments produced high levels of false recall for the critical lure words. Also, the false recall occurred with high confidence levels, meaning the participants were certain the memories were accurate (Roediger & McDermott, 1995). These studies show that false memories can occur quite easily and with confidence. These researchers have successfully replicated the findings in a follow-up study and showed significant results, by using similar methodology, strengthening the idea that false memories can be created in people’s minds
(Stadler, Roediger, & McDermott, 1999).
Okado and Stark (2005) were interested in what fMRI scans would look like when participants were presented with the misinformation paradigm. They wanted to see what areas of the brain were more active when completing memory tasks and how scans compared between false memories and true memories. The researchers told the participants that they were researching the effect of seeing the slide show either once or twice on the participants’ ability to accurately recall various details on a recall test. Participants were presented with eight different vignettes of different events occurring (e.g., “a man breaking into a car.”) Each vignette consisted of 50 slides, 12 of which were considered “target slides” and were altered in some way for the second presentation of the slides. Each slide was presented for 3 seconds. All vignettes were presented one after another with one minute in between. After viewing the vignettes of the original event, participants were presented with the same eight events but saw the changed target slides. After a 48-hour period, participants were presented with a multiple-choice recognition
HANDEDNESS AND FALSE MEMORY 9 test. During the 18-question recognition test, participants were supposed to answer questions such as, “Where did the man hide after breaking into the car?” Twelve of the questions involved the target slides and the remaining six involved standard slides. Aligning well with previous research, participants tended to fall victim to the misinformation paradigm (Okado & Stark,
2005).
Handedness
Functional Magnetic Resonance Imaging (fMRI) has shown individual differences between left- and right-handed people in brain regions related to memory. An fMRI shows specifically which regions of the brain are being activated while the participant is completing a task. Researchers have successfully demonstrated individual differences of handedness when participants performed the word-pair associates learning task (Cuzzocreo et al., 2009). In the word-pair associates learning task, participants heard seven unrelated word pairs (for example, food and book), and then took a recall test in which they were given the first word and were asked to recall the second word that had been paired with it earlier (Cuzzocreo et al., 2009). This study showed that activating the medial temporal lobe (MTL) shows significant differences between left- and right-handed participants. Specifically, activity was significantly greater in left-handed participants (Cuzzocreo et al., 2009).
Interestingly, research has also shown individual differences regarding the size of the corpus callosum in left- and right-handed participants (Christman, Propper, & Dion, 2004;
Clarke & Zaidel, 1994). The corpus callosum is the part of the brain responsible for interhemispheric communication, and research has shown that the corpus callosum seems to be larger in left-handed individuals, leading to better interhemispheric interaction (Clarke & Zaidel,
1994). According to the hemispheric interaction theory, people who exhibit strongly right (SR)-
HANDEDNESS AND FALSE MEMORY 10 handedness (people who almost exclusively use their right hands across various tasks) show less interhemispheric interaction when it comes to various tasks, including memory tasks (Lyle,
McCabe, & Roediger, 2008). Conversely, non-strongly right (nSR)-handedness (people who do not exclusively use their right hands across various tasks) tends to show more interhemispheric interaction when it comes to various tasks, including memory tasks (Lyle et al., 2008). Better interhemispheric interaction has been shown to increase memory performance (Lyle et al., 2008).
Other research has demonstrated that greater interhemispheric interaction leads to better memory via word recall and for personal memories (Propper, Christman, & Phaneuf, 2005). Handedness is also significantly correlated with interhemispheric interaction (Christman, Propper, & Dion,
2004; Propper et al., 2005). Together, this body of research supports the hemispheric interaction theory and connects handedness to memory. Due to the correlational nature of this research, there are some limitations. Although correlational research/data is valuable, research often requires experimental research to truly detect an effect. This type of research would be difficult to conduct experimentally because handedness and corpus callosum size cannot be manipulated, but the research is still important to consider.
Furthermore, researchers have shown in multiple studies that consistency of handedness
(consistently left- or right-handed or inconsistently left- or right-handed) influences individual differences when it comes to memory tasks more than direction of handedness (left- or right- handed) (Lyle et al, 2008; Lyle, Hanaver-Torrez, Hacklander, & Edlin, 2012). Using the
Edinburgh Handedness Inventory (EHI), participants self-reported which hand they use across 10 activities on a Likert scale (always right, usually right, no preference, usually left, and always left; Lyle et al, 2008, Lyle et al, 2012). These items were scored, and the participants were labeled as consistently left- or right-handed or inconsistently left- or right-handed. In the Lyle et
HANDEDNESS AND FALSE MEMORY 11 al (2012) study, participants completed the EHI and then completed a word-pairing test in which they were instructed to learn pairs of words that they would later be tested on their memories of these word pairs (Lyle et al, 2012). Results of this study demonstrated that consistently handed participants (consistently left- and right-handed participants) showed worse memory of the word pairs than did inconsistently handed participants (inconsistently left- and right-handed participants) (Lyle et al, 2008). This research shows that there are individual differences between consistently- and inconsistently-handed individuals.
The Current Study
The goal of the current study was to investigate whether consistency of handedness influences vulnerability to the misinformation effect. Using a 2 (consistently handed vs. inconsistently handed) X 2 (target questions vs. standard questions) mixed-model design, the independent variables were consistency of handedness (consistent or inconsistent) and type of question on the recall test (target questions and standard questions). Consistency of handedness was measured using the Edinburgh Handedness Inventory and the type of information was presented via slide show. The dependent variable was the number of correct answers on the recall tests. Additionally, participants were asked how confident they were about the accuracy of each of their answers.
Christman et al. (2004) has demonstrated that interhemispheric interaction has shown to be better in inconsistently handed individuals. That same research has also shown that better interhemispheric interaction reduced the chance that participants fell victim to false recall when using the DRM task. The current research sought to detect individual differences on consistency of handedness and vulnerability to false recall via the misinformation effect. The research question of the current study was as follows: Are participants with inconsistent handedness less
HANDEDNESS AND FALSE MEMORY 12 likely to be affected by the misinformation effect? I hypothesized that participants categorized as inconsistently handed would be less vulnerable to the misinformation effect (make fewer mistakes) and participants categorized as consistently handed would be more vulnerable to the misinformation effect (make more mistakes). As a secondary research question, I also looked at the relationship between confidence levels and accuracy of memory answers. I hypothesized that there would be no significant difference of level of confidence on accuracy between correct and false memory responses on target questions.
Method
Participants
A total of 153 participants were recruited on the Marietta College campus through the
Sona Systems participant pool (www.marietta.sona-systems.com). Participants were also recruited both on and off campus via email. Students under the age of 18 were allowed to participate with signed parental consent forms. After exclusions, there were 46 male and 90 female participants (n = 136), between the ages 16-71 (M = 24.75, SD = 12.39; see Table 1).
Participants met exclusion criteria if they had outlying scores (2 standard deviations from the mean) on the target questions. In total, 17 participants were excluded1. These exclusions included
13 consistently handed participants and 4 inconsistently handed participants. This took the study from the original 153 participants to 136 participants. G-power analyses showed that with a low effect size (.15), I would need 148 participants to meet statistical significance. After exclusions, there were 97 participants who were consistently handed and 39 participants who were inconsistently handed.
1 Analyses were run both with and without excluded participants and analyses were similar except that error bars became smaller once outlying scores were excluded.
HANDEDNESS AND FALSE MEMORY 13
Materials and Procedure
Participants who were enrolled in Psychology 101 courses signed up through Sona
Systems. All materials were accessible through Qualtrics (www.qualtrics.com), an online software system for administering studies online. Statistical Package of the Social Sciences (IBM
SPSS) was used to analyze the data and produce figures.
Overall, the study took approximately 30 minutes from start to finish. At the beginning of the study, each participant read and signed an informed consent (Appendix A). Additionally, if the participant was under the age of 18, they had to have a signed parental consent form
(Appendix B). This document informed the readers about the basic instructions of the study, any risks that may be involved in participating, and their right to withdraw from the study at any time with no penalty.
The misinformation effect task was adapted using materials from Okado and Stark’s 2005 study. Participants were shown a series of slides from two of Okado and Stark’s (2005) vignettes
(Appendices C and D). Each slideshow was made up of 50 slides, 12 of which were considered target slides (slides that were altered from the first presentation to the second presentation).
The participants then completed a word completion task (Appendix E; Carnagey &
Anderson, 2005) for three minutes to reduce halo effects from the first presentation of each event to the next. There were 100 total items in the word completion task, participants were asked to complete as many as they could in a three-minute time period. This word completion task showed a list of partial words where some letters were replaced with empty spaces. Participants were asked to fill in the blanks to make real words. For many of the items there was more than one possible correct answer. An answer key of many of the possible answers is also provided in
Appendix E, although this task was not scored.
HANDEDNESS AND FALSE MEMORY 14
After completing the filler task, participants were then exposed to the second presentation of the stimuli (Appendices F and G). This consisted of a series of 50 slides depicting the same events in the first presentation, except that the 12 target slides had one specific detail changed.
For example, a man breaking into a car with a credit card in the first slide show and breaking into the same car with a coat hanger in the second slide show. Participants were exposed to each slide for three seconds. It took approximately two and a half minutes to complete each of the two slide shows. The order of presentation was counterbalanced between participants. Half of the participants saw the slideshow of the man breaking into the car first (vignettes in the order of appendices C, D, F, G), and the other half saw the slideshow of the student catching up with his friends at school first (vignettes in the order of appendices D, C, G, F).
After the participant was exposed to both presentations, the participant completed a recognition test (Appendix H). The recognition test consisted of 18 questions and 12 of the questions were considered target questions because they involved the changed detail.
Additionally, the participant’s level of confidence was measured for all questions. After each question, the participants were asked how confident they were on their answer. Confidence for accuracy was measured on a five-point Likert scale from “not at all sure” to “completely sure”
(Mahé et al., 2015). This was to see if confidence levels were different for target slides compared to standard slides.
Next, participants completed the Edinburgh Handedness Inventory (EHI; Appendix I) to measure consistency of handedness. This inventory involved participants answering questions about which hand is typically used when completing specific tasks. These questions were answered on a five-point Likert scale (always right, usually right, no preference, usually left, always left; Lyle et al, 2008). Examples of tasks include: writing, throwing, brushing teeth,
HANDEDNESS AND FALSE MEMORY 15 dealing cards, and brushing hair. Completed inventories were scored as either consistently handed or inconsistently handed. The consistently handed group included both consistently left- and right-handed participants. The inconsistently handed group included both inconsistently left- and right-handed participants, and also the “no preference” and ambidextrous participants. This inventory has been used in several studies and has been shown to be both reliable and valid with a Pearson correlation of .85 (correlation of the consistency of handedness and the activities used to measure consistency). (Christman et al, 2004; Cuzzocreo et al, 2009; Lyle et al, 2008, Lyle et al, 2012, Milenkovic & Dragovic, 2013; Oldfield, 1971).
After completing the EHI, participants filled out a demographics form (Appendix J). This form asked a few questions including age, gender, and a manipulation check (asking if they had any idea what the true purpose of the experiment was with the option to explain their answer).
Finally, there was a debriefing form (Appendix K) stating the true purpose of the study and thanking them for their participation.
The independent variables were consistency of handedness (consistent or inconsistent handedness) and type of question on the recognition test (target and standard questions). The dependent variable was the percent of correct answers on the target questions, where participants were presented with misinformation. The first hypothesis is that the inconsistent group would be less vulnerable to the misinformation effect while the consistent group would be more vulnerable to the misinformation effect. The second hypothesis of the study stated that there would be no significant difference between the confidence levels of accuracy for correct and false memory responses regardless of handedness. The current analyses used a 2 (consistently handed vs. inconsistently handed) X 2 (target questions vs standard questions) mixed-model analysis of
HANDEDNESS AND FALSE MEMORY 16 variance (ANOVA) design, and a G-power analyses showed that I needed 148 participants to meet statistical significance (small effect size of .15 and .95 confidence interval).
Results
All participants watched two different slide shows. The order was counterbalanced to decrease the likelihood of sequencing effects. After running analyses to ensure the level of difficulty for each recognition test were equal, it was found that participants performed significantly more poorly on one recognition test than the other (using the percent correct on target questions), showing that one was more difficult than the other. A within-subjects t-test showed that the slide show involving a student talking with friends in the hallway of a school (M
= .60, SD = .15) was significantly more difficult than the slide show showing a man breaking into a car (M = .83, SD = .10), t(135) = 16.38, p < .001, d = 1.40. Because participants performed significantly worse on one of the tests, analyses were only run on the recognition test of the man breaking into the car2.
For the consistently handed group, the mean score for percent correct on target questions on the recognition test was .83 (SD = .11) and the mean score for percent false memory responses on target questions on the recognition test was .16 (SD = .10). For inconsistently handed participants, the mean score for percent correct on target questions on the recognition test was .84 (SD = .09) and the mean score for percent false memory responses on target questions on the recognition test was .14 (SD = .08; see Table 2 and Figure 1).
For the first research question, it was hypothesized that consistently handed participants would be more vulnerable to the misinformation effect (falling for false memory options significantly more often than inconsistently handed participants). A mixed-model ANOVA was
2 Analyses for both slideshows were run and they yielded similar results, therefore only results regarding the slideshow of a man breaking into a car are presented.
HANDEDNESS AND FALSE MEMORY 17 used to analyze how handedness impacted accuracy on both target and standard questions. The data set did not meet the criteria for Mauchly’s Test of Sphericity and so the Greenhouse-Geisser statistics were used for analyses. There was a main effect of question type. Specifically, accuracy was significantly greater for target questions (M = 83, SD = .10) than standard questions (M =
2 .68, SD = .19), F(1,134) = 61.77, p < .001, ƞp = .32 (See Figure 2). The main effect of question type had an observed power of 1. Additionally, there was no main effect of handedness, F(1,134)
2 = 1.57, p = .21, ƞp = .01. This had an observed power of .24. Using a between-subjects t-test, it was found that there was no statistical difference between consistently handed participants (M =
.83, SD = .11) and inconsistently handed participants (M = .84, SD = .09) regarding performance on the recognition test, t(134) = -.84, p = .41, d = .16. Finally, there was not a significant interaction for the type of question (target versus standard questions) and handedness
2 (inconsistently versus consistently handed), F(1,134) = .45, p = .50, ƞp = .003 (See Figure 3)
This interaction had an observed power of .10.
The secondary hypothesis stated that there would be no significant difference between correct and false memory responses regarding levels of confidence on responses on the recognition test. A mixed-model ANOVA was run to determine how handedness affected confidence scores on correct responses and false memory responses. Confidence scores were compared across correct and false memory responses on target questions. Again, the data set did not meet the criteria for Mauchly’s Test of Sphericity and so the Greenhouse-Geisser statistics were used for analyses. Overall, there was a main effect of average confidence scores, F(1, 117)
2 = 107.13, p <.001, ƞp = .48, with an observed power of 1. Specifically, the average confidence scores for correct responses (M = 4.47, SD = .43) was significantly greater than average confidence scores for false memory responses (M = 3.4, SD = 1.15). Additionally, there was no
HANDEDNESS AND FALSE MEMORY 18
2 main effect of handedness, F(1, 117) = 2.24, p = .14, ƞp = .02. This main effect of handedness had an observed power of .32. Finally, there was no significant interaction between average confidence scores on correct and false memory responses and handedness, F(1, 117) = 2.96, p =
2 .09, ƞp = .03. This interaction had an observed power of .40.
Discussion
Regarding the comparatively poor performance on the slideshow involving the students talking in the school hallway, a possible explanation for participants’ performance on the recognition test could be the overall interest in the topic of the slide show. Participants might have found the slide show of the man breaking into the car and stealing various items (money, jewelry, and drugs) more interesting than a student seeing friends in the hallway of a school and talking about tests. If participants did find the presentation of the student at school less interesting, or less salient, it is possible they didn’t pay as close attention as they did for the car break-in slide show. A measure of attention may help illuminate one possible mechanism for production of false memory.
The main hypothesis predicted that inconsistently handed participants would be less vulnerable to the misinformation paradigm compared to consistently handed participants. The results show that there were no significant differences between inconsistently handed and consistently handed participants regarding vulnerability to the misinformation paradigm
(performance on the recognition test; see figure 2). The analyses of the interaction had a low observed power of .10. This means that both consistently and inconsistently handed participants were equally vulnerable to false memories. In the current study, a probable explanation for these results is the lack of statistical power. The analyses of the interaction had a low observed power of .10. Due to not having enough participants to reach statistical power according to G-Power
HANDEDNESS AND FALSE MEMORY 19
(148 participants were needed) the observed power of all analyses were fairly small.
Additionally, the two groups were very unequal, having 97 consistently handed participants and
39 inconsistently handed participants (See Table 1).
The secondary hypothesis stated that participants would be just as confident in their false memories (false memory responses on the recognition test) as they would be for their true memories (correct responses on the recognition test). It was predicted that there would be no statistical difference between confidence scores for correct versus false memory responses.
However, the results showed a significant difference in confidence scores across each response type. Specifically, participants were more confident in their correct responses than they were in their false memory responses (See Figure 4). Past research has shown that participants are just as confident in their true memories as they are in their false memories (Loftus & Pickrell, 1995).
Another possible explanation for these insignificant findings could be the way the misinformation paradigm was set up in this study. The typical setup of the misinformation paradigm is to present a short video or slide show presentation, and then after a specified amount of time, present misinformation via audio recording or in a written format. In my search of the current literature available, I found very few studies to have the same or similar format utilized in this study (i.e., Okado & Stark, 2005; Manning and Loftus, 1996). Okado and Stark’s rationale for using this methodology was because they were looking at neural activity and they needed to access the same area of the brain for both presentations of the event to ensure better accuracy
(Okado & Stark, 2005). Additionally, Okado and Stark showed participants eight different vignettes solely because they were looking at fMRI scans and this increased the number of data points to look at for analyses (Okado & Stark, 2005). Manning and Loftus (1996) is another study I have found where the methodology utilized two slideshow presentations instead of the
HANDEDNESS AND FALSE MEMORY 20 typical setup. Manning and Loftus were able to find that when participants are presented with misleading information after viewing an original event (this was done via slideshow, having certain details changed in the second presentation), that false memory does occur (Manning &
Loftus, 1996). Specifically, participants who were not presented with misleading information scored an average of 72% on the recognition test, while participants who were exposed to misleading information scored an average of 61% on the recognition test (Manning & Loftus,
1996).
Further research would be needed to determine if this type of misinformation paradigm does yield individual differences regarding handedness. A possible reason that my results did not align with these two studies is that I did not follow their exact protocols used in their studies.
Okado & Stark looked at eight different vignettes consecutively and did not give the recognition test directly after. Manning & Loftus only used one slideshow and their control group was different from Okado & Stark’s (and mine). Some participants received misleading information
(via changed or “target” slides) and others did not receive any misleading information. In the
Okado & Stark research, there were target and standard questions and the standard questions acted as each participant’s control questions.
One limitation to this study is that I did not have the minimum number of participants for analyses according to my G-Power analyses. G-Power analyses showed that I would need a minimum number of 148 participants to reach statistical significance, and I had 136 after exclusions. Additionally, after exclusions, there were 97 consistently handed participants and 39 inconsistently handed participants, leaving me with unequal groups, which could have potentially impacted my results. Future research should strive for more participants as well as more equal groups and this should strengthen effect sizes and the observed power.
HANDEDNESS AND FALSE MEMORY 21
Participants performed better on target questions than they did on standard questions overall (See Figure 3). The standard questions were meant to serve as a control, or baseline, for memory performance because these questions were about slides that did not change from presentation 1 to presentation 2. A possible explanation for this could be the salience of the questions. These questions contained mostly peripheral information that people may be likely to ignore, or not remember. For example, questions included how close the car was parked to a tree
(15 feet), what the man found in the purse in the backseat of the car (nothing), and what the make of the car parked behind the car that was being broken into was (Toyota). It is possible that these questions were difficult to answer because they are more peripheral as opposed to central.
Peripheral details may not be as salient, or as easily remembered, and can therefore decrease accuracy on a recognition test. Distance can be difficult to perceive in a picture, the man found nothing in the purse as opposed to finding an actual object and participants may have assumed he must have found something, and finally, participants likely did not pay attention to the car parked behind the car being broken into. Many participants chose “Honda” instead of the correct answer “Toyota” and this is likely because the car that was broken into was easily recognizable as a Honda Civic. Future research should use standard questions (control or baseline questions) that are just as salient as target questions or are more central in nature to ensure that both standard and target questions are equal in level of difficulty and salience.
In conclusion, future studies should analyze false memories and handedness using different methodology. These studies should utilize different types of false memory paradigms
(such as the more common forms of the misinformation paradigm or the DRM task).
Additionally, in past research, participants have shown to be just as confident on false memories as they are on true memories in many research studies and this should be further explored
HANDEDNESS AND FALSE MEMORY 22 regarding how the misinformation was given to induce the false memory. If researchers are using more than one presentation, their level of difficulty, level of interest, and types of memories being created (central versus peripheral and semantic versus episodic) should be as equal as possible to minimize any possible confounds. Control questions (standard questions) should be equally as salient as the target questions again to avoid potential confounds in the research.
Overall, examining if handedness increases vulnerability to false memories can be beneficial to scientific knowledge. In short, knowing if handedness is a predictor of vulnerability to false memory could lead to more research on how handedness impacts other areas of human behavior.
This could include changing how eyewitness testimonies are conducted, or even how neurological scans are looked at or utilized (due to inconsistently handed people having more interhemispheric interaction than consistently handed individuals). Additionally, understanding the underlying mechanisms behind why inconsistently handed participants tend to perform better on various tasks (such as memory and false memory tasks) can open a whole new realm of research that may be worth looking deeper into. This topic requires further research to continue closing this gap in current knowledge.
HANDEDNESS AND FALSE MEMORY 23
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HANDEDNESS AND FALSE MEMORY 24
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HANDEDNESS AND FALSE MEMORY 25
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HANDEDNESS AND FALSE MEMORY 26
Table 1 Descriptive Statistics of Participants Consistent Handedness Inconsistent Handedness n Range M SD n Range M SD Sex Male 35 11 Female 62 28 Age 16-69 24.26 11.43 18-71 25.97 14.60 Note. This table shows the descriptive statistics (age and gender across conditions) of the individuals who participated in the current research study (n = 136).
HANDEDNESS AND FALSE MEMORY 27
Table 2 Accuracy on Target and Standard Questions Consistent Handedness Inconsistent Handedness Target Standard Target Standard M SD M SD M SD M SD Correct .83 .11 .67 .20 .84 .09 .71 .17 FM .16 .10 .14 .08 Incorrect .02 .04 .33 .20 .02 .04 .29 .17 Note. This table shows mean scores (proportion) of accuracy for correct, false memory (FM) and incorrect responses for consistency of handedness and question type (target versus standard questions). Additionally, there was no false memory option for standard questions (n = 136).
HANDEDNESS AND FALSE MEMORY 28
Table 3 Average Confidence Scores Consistent Handedness Inconsistent Handedness M SD M SD Correct (n = 136) 4.48 .44 4.47 .40 FM (n = 119) 3.52 1.09 3.12 1.28 Incorrect (n = 24) 3.47 1.11 2.94 .88 Note. This table show the average confidence scores for correct, false memory (FM), and incorrect responses for handedness.
HANDEDNESS AND FALSE MEMORY 29
Figure 1. This graph shows the mean scores for consistently and inconsistently handed participants for both correct and false memory responses.
HANDEDNESS AND FALSE MEMORY 30
Figure 2. This graph shows the average accuracy for both target and standard questions across both handedness conditions.
HANDEDNESS AND FALSE MEMORY 31
Figure 3. This line graph shows consistently and inconsistently handed participants’ accuracy on target and standard questions.
HANDEDNESS AND FALSE MEMORY 32
Figure 4. This graph shows the average confidence scores for each type of response (correct, false memory, and incorrect responses) for consistently and inconsistently handed participants.
HANDEDNESS AND FALSE MEMORY 33
Appendix A Informed Consent Project Title: Study of Memory
Primary Investigator: Stephanie Monroe (740) 408-3365 in the Department of Psychology at Marietta College
You are being asked to participate in a project conducted through Marietta College. You must be at least 18 years of age to participate. Below is an explanation of the purpose of the project, the procedures to be used, and the potential benefits and possible risks of participation.
Nature and Purpose of Project: The goal of the current study is to determine certain characteristics of the general population regarding memory and word tasks.
Explanation of Procedures: In short, participants will be asked to view a series of slide shows as well as complete a few short questionnaires and tasks. Specifically, participants will complete a recall test after each slideshow has been viewed, complete an easy task, and end with one additional questionnaire followed by some demographic questions. Please answer all questions truthfully. In total, the study should take no more than 30 minutes.
Discomfort and Risks: There are minimal dangers or risks involved in this study. Your participation is completely voluntary, and you have the right to withdraw from the study at any time without penalty.
Benefits: The results of this study provide the researchers with valuable scientific data. Also, participants from Marietta College Sona Systems will receive 0.5 participation credits.
Confidentiality: Your responses on all the tasks will be completely anonymous; they will not be identified with you in any way. Data will be available in anonymized form for future statistical analysis by the primary investigator. This information will be electronically stored within the Marietta College Psychology Department in a locked cabinet.
By signing below, you are indicating your consent to participate in this research and you acknowledge that your participation in the study is voluntary, you are 18 years of age, and that you are aware that you may choose to quit the study at any time without penalty. You understand that all information collected from you will only be used for research purposes and will be kept confidential. The risks to answering these questionnaires are minimal. This study should take no more than 30 minutes to complete.
I consent to participating in this study:
Name (print): ______Date: ______
Signature: ______Email address: ______
* This research has been approved by the Marietta College Human Subjects Committee website: http://faculty.marietta.edu/humansubjects/index.html).
If you have questions or concerns about the study, you may contact myself (contact information is provided above). You may also contact the chair of the college human subjects committee, Dr. Mary Barnas, with concerns regarding your personal rights as a research participant at [email protected].
HANDEDNESS AND FALSE MEMORY 34
Appendix B Parental Informed Consent Project Title: Study of Memory
Primary Investigator: Stephanie Monroe (740) 408-3365 in the Department of Psychology at Marietta College
Your child is being asked to participate in a project conducted through Marietta College. If your child is under the age of 18, I am requesting your parental consent to allow your child to participate. Below is an explanation of the purpose of the project, the procedures to be used, and the potential benefits and possible risks of participation.
Nature and Purpose of Project: The goal of the current study is to determine certain characteristics of the general population regarding memory and word tasks.
Explanation of Procedures: In short, participants will be asked to view a series of slide shows as well as complete a few short questionnaires and tasks. Specifically, participants will complete a recall test after each slideshow has been viewed, complete a word task, and end with one additional questionnaire followed by some demographic questions. Your child will be asked to answer all questions truthfully. In total, the study should take no more than 30 minutes.
Discomfort and Risks: There are minimal to no dangers or risks involved in this study. Your child’s participation is completely voluntary, and they have the right to withdraw from the study at any time without penalty.
Benefits: The results of this study provide the researchers with valuable scientific data. Also, your child will receive 0.5 participation research credits toward their class grade.
Confidentiality: Your child’s responses on all the tasks will be completely anonymous; they will not be identified with your child in any way. Data will be available in anonymized form for future statistical analysis by the primary investigator. This information will be electronically stored within the Marietta College Psychology Department in a locked cabinet.
By signing below, you are indicating your consent to allow your child to participate in this research and you acknowledge that their participation in the study is voluntary, and that you are aware that you may choose to quit the study at any time without penalty. You understand that all information collected from your child will only be used for research purposes and will be kept confidential. The risks to answering these questionnaires are minimal. This study should take no more than 30 minutes to complete.
I consent to my child participating in this study:
Name (print): ______Date: ______
Signature: ______Email address: ______
* This research has been approved by the Marietta College Human Subjects Committee website: http://faculty.marietta.edu/humansubjects/index.html).
If you have questions or concerns about the study, you may contact myself (contact information is provided above). You may also contact the chair of the college human subjects committee, Dr. Mary Barnas, with concerns regarding your personal rights as a research participant at [email protected].
HANDEDNESS AND FALSE MEMORY 35
Appendix C
Presentation of original event (Sequence 1)
1 2 3 4
5 6 *7-Credit Card 8
9 10 11 *12-$1
13 14 15 16
HANDEDNESS AND FALSE MEMORY 36
17 18 19 20
*21-Close 22 23 24
25 26 27-Nobody 28
*29-C 30-Neclaces 31 32
HANDEDNESS AND FALSE MEMORY 37
33-Left *34-Hit 35 36
37 38 39 40-Nothing
*41-Key 42 43 44
45-Left 46 47 48
49 50-Hat off
HANDEDNESS AND FALSE MEMORY 38
Appendix D Presentation of original event (Sequence 2)
*1-Leaning Over 2 3 4
5 6 7-BSection 8
9 10 11 *12-Button Down Shirt
13 14-English *15-Math 1:15 16-No Back Design
HANDEDNESS AND FALSE MEMORY 39
17 18 19 20
*21-Black Notebook 22 *23-Exam Monday 24
25-Laugh 26 27 28
29-Psych Text 30 31 32
HANDEDNESS AND FALSE MEMORY 40
33 34 35 36
37 38 39 *40-Friend Cell
41 42 43 44
45 46 47-Orange Post-it 48
49 50
Running head: HANDEDNESS AND FALSE MEMORY 41
Appendix E
Word Completion Task Directions: Please fill in the blanks to make each partial word into full, real words. There is often more than one correct answer. 21. r _ p _ _ t 42. a n g _ _ 1. b _ h_ _ _ 22. s t r _ _ e 43. f l _ _ t 2. _n _ u re 23. l _ _ e 44. f I _ _ t 3. ex _ e _ _ 24. b _ r n 45. p _ c k 4. m u _ _ e r 25. s t _ r _ o 46. h a _ e 5. p r _ _ e 26. p _ _ s o n 47. a _ t 6. s p e a _ 27. p _ s t _ r 48. c _ t 7. f l i _ _ e r 28. m _ _ g l e 49. w _ n 8. e x p l _ _ e 29. b l _ n d 50. a _ e 9. w _ _ m 30. s n _ r e 51. _ r y 10. k i _ _ 31. b _ e 52. w a _ 11. t _ p _ 32. h _ t 53. f _ m _ 12. h _ r _ 33. g _ _ p e 54. s l _ p 13. a _ t _ r 34. s m _ c k 55. b _ _ k 14. c h o _ e 35. s m _ _ e 56. r _ p e 15. s _ m p _ _ 36. k n _ _ _ 57. f o _ e _ t 16. a t t _ c _ 37. t _ n e 58. o f f _ _ _ 17. c _ m p _ _ t 38. s _ _ b 59. l _ _ o n 18. d e s _ _ _ _ 39. s h _ r _ 60. c r _ _ l 19. s h _ l _ 40. d r _ _ n 61. c _ e _ t e 20. s h o _ t 41. p _ _ n e 62. s t _ r _ y HANDEDNESS AND FALSE MEMORY 42
63. m _ t c _ 84. b _ _ t
64. f _ r _ _ 85. b r _ _ z e
65. t _ _ t e 86. r e v _ _ t
66. n _ _ t _ 87. c o o _
67. w _ _ d _ w 88. s _ _ y
68. w _ _ k e d 89. d _ _ r
69. v i s _ _ n 90. s m _ c k
70. e n _ a g e 91. f r _ _ t
71. s c r _ _ n 92. _ u n c h
72. h _ t r _ d 93. s h _ r e
73. t _ l _ p h _ _ _ 94. a _ u s e
74. d i s _ _ s _ e d 95. c l _ _ r
75. c _ n t _ _ l 96. h _ n t
76. p r o v _ _ e 97. w _ t _ r
77. p _ n b _ l l 98. s _ a s h
78. o u t _ _ _ e 99. r o a _
79. c _ l l 100. t i _ e
80. r _ d e
81. m _ n _ g e
82. i n s _ _ _
83. s _ d _
HANDEDNESS AND FALSE MEMORY 43
Appendix E (Continued) Word Completion Task Scoring Scoring: Below are possible answers for the Word Completion task, there may still be other possible answers. 7. flipper hero 1. behind flitter have behead flicker horn behave flirter hark behold 8. explore 13. after behalf explode alter behest 9. warm aster wham 2. insure actor worm injure altar whim ensure 14. chore endure whom choke 3. exceed 10. kite chose kick expect 15. sample extent kiss simple extend kill simply except kilt simper excess king 16. attach expert kids attack expend kind attics extern kiwi 17. compact excels kink complot 4. mutter kilo compost murder 11. tips comport 18. dessert muster tops deserts mugger taps destroy 5. pride tope desires prime typo despise prize type deserve prude tape destiny prove 12. hare desired price hurl designs prune hurt despair prose hire despite probe harm descent 6. speak hard spear here descend hers desktop 19. shale CONSISTENCY OF HANDEDNESS 44
shall sterno 38. snob shelf 26. person stab shell prison slab shalt poison slob shill 27. poster snub 20. short pester scab shoot pastor stub shout 28. mingle 39. short 21. repeat mangle shark rapist muggle shore report 29. blind sharp repent blond share 22. strife blend shirt strike bland shirk stroke 30. snore 40. drain stripe snare drown strive 31. bye drawn bee stride 41. plane 32. hat 23. line Prone hit lure Prune hut lyre Phone hot lore 42. angel 33. grape love gripe angle live grope anglo lose 34. smock anger lone smack angry like 35. smile 43. flirt life smite fleet lake smoke float lane 36. kneel flint lime knave 44. first lope knife filet laze known fight lace knock 45. pack lame knits pick lice knees puck lat knack peck 24. born kneed 46. hare burn 37. tone have barn tine hale 25. stereo tune haze
CONSISTENCY OF HANDEDNESS 45
hate Back Farts 47. ant Beak Forum Act Buck Forgo Art Bank Farse apt Bunk forte 48. cat 56. ripe 65. taste cot Rape Trite 49. won rope 66. nifty win 57. forest Ninth wan foment Nasty 50. ate 58. offset Nutty ale offers Nests are office Newts age offend north ace 59. lemon 67. window aye Logon 68. winked awe licon Worked ape 60. crawl Walked axe cruel wicked 51. try 61. create 69. vision Cry 62. starry 70. engage Dry Sturdy enrage Fry stormy 71. screen Wry 63. match 72. hotrod pry mitch hatred 52. was 64. furry 73. telephone Way Forty 74. dismissed Wax Fires Discussed Wad Force disgusted Wag Fired 75. central Wan Faves control War Firey 76. provide 53. fame Farms provoke fume First 77. pinball 54. slip Forks 78. outcome Slap Forge Outside slop Forms Outline 55. book Forth Outdate Bark Fares Outdone Balk Ferry outrage
CONSISTENCY OF HANDEDNESS 46
79. call Bout Frost cell Best 92. lunch 80. rode Belt Punch Ride Bust Munch Rude Brat Bunch 81. manage 85. bronze hunch 82. insect breeze 93. shore Insist 86. revert share Insult revolt 94. amuse Insure 87. cool abuse Inside Cook 95. clear Insert Coon 96. hint Insane Coop hunt Insole 88. sony 97. water Instep Stay 98. stash 83. side Sway Swash Soda Sexy Slash suds Spry smash 84. bolt slay 99. road Bait 89. deer Roar Boot Door 100.time Butt Dear Tire Beat dour Tile Boat 90. smock Tide Bunt smack Tine Blot 91. fruit Beet Front
HANDEDNESS AND FALSE MEMORY 47
Appendix F Presentation 2 of event, with the 12 target slides having changed details.
1 2 3 4
5 6 *7-Hanger 8
9 10 11 *12-$20
13 14 15 16
HANDEDNESS AND FALSE MEMORY 48
17 18 19 20
*21-Open 22 23 24
25 26 27-Stranger 28
*29-M 30-Rings&Watch 31 32
33-Right *34-Kick 35 36
HANDEDNESS AND FALSE MEMORY 49
37 38 39 40-Tape
*41-Papercard 42 43 44
45-Right 46 47 48
49 50-Hat on
HANDEDNESS AND FALSE MEMORY 50
Appendix G Presentation 2 of event, with the 12 target slides having changed details.
*1-Sitting Up 2 3 4
5 6 7-Front Page 8
9 10 11 *12-Regular Tshirt
13 14-History *15-Math 3:30 16-Back Design
HANDEDNESS AND FALSE MEMORY 51
17 18 19 20
*21-Red Notebook 22 *23-Exam Thursday 24
25-Scared 26 27 28
29-Stats Textbook 30 31 32
HANDEDNESS AND FALSE MEMORY 52
33 34 35 36
37 38 39 *40-Student Cell
41 42 43 44
45 46 47-White Post-it 48
49 50
HANDEDNESS AND FALSE MEMORY 53
Appendix H Recognition Tests
Subj ID: ______Date: ______
Instructions:
This test pertains to the story you saw about the young man breaking into a car and stealing some items from the car.
Please answer the questions according to what you remember from the event that you saw.
1. During the second presentation of the event, what type of jewelry did the man find in the trunk?
a. Necklaces b. Earrings c. Rings and a watch d. bracelets
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
2. During the second presentation of the event, which shoe(s) did the man bend down to tie? ___
a. Right b. Left c. Both d. none
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
3. During the first presentation of the event, approximately how far was the car parked from the tree in front of it? ___
a. Two feet b. Fifteen feet c. Forty feet d. One hundred feet
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 54
4. During the first presentation of the event, what did the young man find in the purse that was inside the car? ___
a. Wallet b. Jewelry c. Nothing d. keys
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
5. During the first presentation of the event, what type of bills did the young man find in the change compartment? ___
a. $1.00 b. $5.00 c. $20.00 d. $50.00
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
6. During the second presentation of the event, after the young man opened the trunk, he thought he heard a noise and looked across the street. What did he find? ___
a. A couple holding hands b. A man walking his dog c. Nothing d. A child playing
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 55
7. During the second presentation of the event, on which hand(s) did the young man accidentally slam the trunk on? ___
a. Right b. Left c. Both d. Neither
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
8. During the first presentation of the event, how did the man open the trunk? ___
a. Crow bar b. Hanger c. Lever d. screwdriver
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
9. During the first presentation of the event, what was in the bag that the young man found in the trunk? ___
a. Cocaine b. Marijuana c. Cigarettes d. Chewing tobacco
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
10. During the second presentation of the event, what did the man take from the glove compartment?
a. Cassette Tape b. Nothing c. Pen d. Insurance card
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 56
11. During the first presentation of the event, what did the young man use to break into the car? ___
a. Credit card b. Crow bar c. Hanger d. Screwdriver
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
12. During the first presentation of the event, what did the man, in frustration, do to the car after he slammed the trunk on his hand(s)?
a. Kicked the car b. Hit the car c. Scratched the car d. Hit the car with a hammer
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
13. During the first presentation of the event, what university sticker was on the rear window? ___
a. Johns Hopkins University b. University of Maryland c. University of Chicago d. Miami University
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
14. During the first presentation of the event, when the man exited the car from the driver-side to head towards the trunk, what did he do to the door? ___
a. Kicked it b. Closed it c. Left it open d. Rolled down the window
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 57
15. During the second presentation of the event, as the man ran away, what happened to his hat? ___
a. Fell off b. He noticed it was gone c. Nothing d. It got dirty
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
16. During the first presentation of the event, what did the man find underneath the sunshade?
a. Key b. Paper slip c. Money d. Napkins
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
17. During the first presentation of the event, what coins were in the change compartment? ___
a. Pennies b. Dimes c. Quarters d. Nickels
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
18. During the first presentation of the event, what type of car was parked behind the car the young man broke into? ___
a. Honda b. Ford c. Toyota d. Chevy
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 58
Subj ID: ______Date: ______
Instructions:
This test pertains to the story you saw about the student, Nicholas, sitting in a hallway studying between classes. He runs into three friends: Henry, displaying his new shirt; Frank, wanting to know when an exam was scheduled; and Stephanie, a good friend, whose conversation was interrupted by a cell phone call.
Please answer the questions according to what you remember from the event that you saw. CIRCLE the correct letter for each question. Please use the pen provided.
1. During the first presentation of the event, how does Nicholas leave the classroom? ___
a. He leaves the door open b. He closes the door c. He slams the door closed d. He kicks the door open
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
2. During the first presentation of the event, what was the color of the notebook Nicholas used to check the exam day for his friend, Frank?
a. Red b. Blue c. Black d. Green
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
3. During the first presentation of the event, what day was the exam going to be? ___
a. Monday b. Tuesday c. Thursday d. Wednesday
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 59
4. During the first presentation of the event, what kind of shirt was Nicholas’ friend, Henry (with the curly hair) showing off? ___
a. Button-down shirt with short sleeves b. T-shirt c. Button-down shirt with long sleeves d. Sweater
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
5. During the first presentation of the event, from what direction did Henry come to say hello to Nicholas? ___
a. From Nicholas’ right b. From the Nicholas’ left c. It was not shown d. From the front
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
6. During the second presentation of the event, when Nicholas told his friend, Frank (with the buzzed haircut) about when the exam day was, what was the Frank’s reaction? ___
a. Laughter b. Tears c. Horror d. Calm
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 60
7. During the first presentation of the event, in what manner does Stephanie, Nicholas’ girlfriend, react to Nicholas’ question? ___
a. She nods her head to signify yes b. She shakes her head to signify no c. Shrugs her shoulders to signify she does not know the answer d. She answered excitedly
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
8. During the second presentation of the event, what section of the newspaper was Nicholas reading when he first got to the bench? __
a. First section b. B Section c. Classifieds d. Comics section
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
9. During the first presentation of the event, how was Nicholas sitting when he was writing his notes in the classroom? ___
a. Sitting straight up b. Leaning over his notebook c. Slouching back in the chair d. He was standing up
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 61
10. During the first presentation of the event, what kind of shoes was Nicholas’ girlfriend, Stephanie, wearing? ___
a. Sneakers b. Platform shoes c. Wooden clogs d. Flats
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
11. During the first presentation of the event, how did Nicholas react to seeing Stephanie?
a. Surprised b. Happy c. Angry d. Sad
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
12. During the first presentation of the event, while Nicholas and Stephanie were talking, who had to answer a call on their cell phone? ___
a. Nicholas b. Stephanie c. Frank (with the buzzed haircut) d. A nearby stranger
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 62
13. During the second presentation of the event, what was the study guide Nicholas was reading when his girlfriend, Stephanie, walked by? ___
a. Biology b. Statistics c. Psychology d. History
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
14. During the second presentation of the event, what was Nicholas’ t-shirt like? ___
a. Solid gray t-shirt b. Theater t-shirt with paint stains on the back c. Theater t-shirt without paint stains on the back d. A black pattern on the back
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
15. During the first presentation of the event, was there a water fountain in the building Nicholas was sitting in? ___
a. Yes b. No c. It was not shown d. There were two water fountains
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 63
16. During the second presentation of the event, what class did Nicholas cross out in his daily planner? ___
a. Psychology b. History c. English d. Biology
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
17. During the first presentation of the event, what time was Nicholas’ next Math class going to be? ___
a. 9:00am b. 1:15pm c. 3:30pm d. 8:15am
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
18. During the second presentation of the event, what color was the post-it note Nicholas used to mark his place in the textbook? ___
a. Green b. Orange c. Light Blue d. Pink
Please rate your level of confidence on your response.
Not at all sure Completely sure 1 2 3 4 5
HANDEDNESS AND FALSE MEMORY 64
Appendix I Edinburgh Handedness Inventory (EHI)
Please indicate which hand most applies to each activity.
Always Left Usually Left No Preference Usually Right Always Right Writing 1 2 3 4 5 Drawing 1 2 3 4 5 Throwing 1 2 3 4 5 Scissors 1 2 3 4 5 Brushing teeth 1 2 3 4 5 Opening a lid 1 2 3 4 5 Using a spoon 1 2 3 4 5 Brushing hair 1 2 3 4 5 Using a knife 1 2 3 4 5 Striking a match 1 2 3 4 5
Scoring:
Consistently Left (10-17) Inconsistently Left (18-25) No Preference (26-34) Inconsistently Right (35-42) Consistently Right (43-50)
HANDEDNESS AND FALSE MEMORY 65
Appendix J Demographic Form
Please answer a few brief demographic questions: 1. Age: ____
2. Gender: a. Male b. Female c. Other d. Prefer not to answer
3. Do you know, or have any idea of what the true purpose of the study was? a. Yes b. No c. Not sure
4. If you answered yes or not sure to question 5, please explain what you believe the true purpose of the study is:
HANDEDNESS AND FALSE MEMORY 66
Appendix K
Debriefing Statement
The actual purpose of this study was to determine individual differences between handedness and memory. Participants completed a handedness inventory and were characterized as consistently handed (strictly left- or right-handed) or inconsistently handed (tends to use both hands, it depends on the task). All participants viewed two brief slide shows with a task separating the two slide shows. The two slide shows were similar, although there were some minor differences. The recall test then asked you to answer accurately based off the first slide show you saw. The minor changes may have lead participants to potentially falsely recall details of the video.
This study was important to conduct because there is a large body of research suggesting that people who are left handed (who typically display inconsistent handedness) perform better on memory tasks. The purpose of the current study was to fill a gap in the literature demonstrating that inconsistently handed participants are less vulnerable to false memory tasks.
If you have any questions or concerns regarding your rights as a participant, you may contact Dr. Mary Barnas at [email protected]. If you have any questions regarding the study or would like a personal copy of the informed consent or debriefing statement, please feel free to contact me at [email protected].
If you experienced any discomfort for any reason please locate resources in your area, or contact the Crisis Help Line at 800-233-4357. Your participation is greatly appreciated.
Thank you.