Using a Classroom-Based Deese Roediger McDermott Paradigm to Assess the Effects of Imagery on False Memories

Summary

The method presented here induced false memories using lists of related words and also assessed the effects of imagery instructions on the recall and recognition of those false memories. This protocol details a modified version of the Deese Roediger McDermott (DRM) paradigm.

Abstract

Associated word list procedures can elicit false memories in predictable ways by inducing associative processing, thus making it harder to monitor the accuracy of memories. The purpose of the method presented here was to induce false memories using lists of either semantically or phonologically related words and to assess the effects of imagery instructions on the recall and recognition of those false memories. To do this, we used a modified version of the Deese Roediger McDermott (DRM) paradigm. We adapted word lists from previous DRM studies to suit imagery procedures and created an automated presentation to present the word lists in classroom settings. We then recruited undergraduate classes and instructed some of the classes to create mental images of the list words as they were being presented, while instructing the other classes to simply remember the words. The automated presentation presented word lists to participants, one word at a time, alternating between phonologically and semantically related lists. Participants used paper-pencil recall packets to immediately recall list items, complete a distractor activity, and take a subsequent final recognition test. Often, participants immediately recalled and later recognized words that were related to the list items but were not actually presented; these are known as critical lures and indicate a false memory. The protocol detailed here describes a four-step procedure - list presentation, immediate recall, distractor phase, and final recognition - that can assess the effects of list type and imagery instruction within the DRM paradigm on memory. The automated nature of the list presentation provides the ability to systematically vary variables of interest, and the paper and pencil method of data collection affords an easily accessible method for collecting data in classroom settings. The protocol also offers options to modify the procedure to a more traditional DRM paradigm without imagery and/or list type manipulations. The use of this protocol can provide results relevant to both classroom learning and cognitive science principles.

Introduction

Memory is malleable and fallible, and these days people realize the limitations of their own memory system. But how do memory errors arise? What mechanisms are responsible for errors in memory retrieval? We modified a widely used and highly cited laboratory-based procedure called the Deese Roediger McDermott paradigm (DRM)^1,2 to investigate the influence of different variables on memory errors. In traditional DRM procedures, participants are asked to learn lists of semantically related words (e.g., table, couch, desk, lamp, pillow, stool, bench, rocker). When later asked to recall and/or recognize the words from the lists, participants often report seeing words that were semantically related to the lists but not actually studied (e.g., chair). False memories for these words, referred to as critical lures, can occur 55% - 80% of the time in standard procedures^2,3.

The Activation Monitoring Framework is often cited as a theoretical basis for memory errors that arise from the DRM paradigm. Specifically, DRM false memories are attributed to the dual processes of activation (i.e., the tendency for pieces of information currently active in working memory to "spread" and also activate other, related pieces of information) and monitoring (i.e., assessing the accuracy and/or source of something being remembered)^5,6. The process of studying semantically related DRM lists causes activation to spread from the list words to the critical lure and thus activates the critical lure in working memory. The result is a false memory that may not be accurately monitored during later tasks.

The three-phase testing procedure inherent to the DRM paradigm allows cognitive psychologists to manipulate a number of variables during the process of encoding (study of the list items), retention (storage of the list items while completing a distractor task to disrupt working memory), or retrieval (a memory test), to better understand the specific processes that contribute to memory errors. Our procedure expands use of traditional DRM procedures to directly compare memory error rates for different types of content during encoding (e.g., semantically related versus phonologically related)⁹, test type during retrieval (e.g., a recall task versus a recognition task)¹⁰ and, perhaps most notably, imagery encoding processes during list study^11,12,13,14.

Our primary interest in developing this protocol was to better understand possible effects of imagery on recall and recognition, particularly whether the effects of creating mental images of the list words during encoding (e.g., imagining them) would vary according to whether the list words were related to the critical lure according to sound (i.e., phonologically) or meaning (i.e., semantically). For instance, for the phonological list log, hog, dock, bog, fog, doll, frog, jog, and dot, the critical lure is dog. For the semantic list mug, saucer, tea, coaster, lid, coffee, straw, and soup, the critical lure is cup. We were interested in whether imaging the list words affected the associative processing for those lists differently. While traditional DRM word lists contain 12-15 semantically related list words², our procedure employed 8-item word lists. These lists were modified from 16-item lists previously developed to investigate the converging effects of phonological and semantic word associations on false memories⁹. In order to adapt typical DRM procedures to include imagery instructions, we shortened the word lists by selecting the 8 words from each list that were easiest to create mental images of. This allowed for the elimination of less concrete words (e.g., pun, worst) that were hard to imagine. Additionally, we modified a computer-based word list presentation utilized in previous research¹⁵ to standardize the presentation of materials and also developed paper/pencil recall and recognition measures to more appropriately suit classroom environments.

Our results did not suggest an interaction between list association type and imagery procedures, but they did demonstrate the significant main effects of imagery and list type¹⁴. We pursued this line of inquiry because of the robust literature of imagination inflation effects suggesting enhanced feelings of belief and memory in past childhood events that are repeatedly imagined^16,17,18. However, recently researchers suggest that perhaps not all imagery is created equal and that the nature of imagery instructions mediates the effects on false memory rates¹⁹. One possible limitation to the work assessing imagination inflation effects is inherent in the procedure itself. That is, participants are asked to provide Likert scale ratings of their confidence or belief in experiencing certain events in childhood, and following imagination of those events, ratings are provided a second time to assess changes (specifically increases) in those ratings. One possible problem with this procedure is a lack of control over the veracity of experiences that participants must identify with confidence ratings both prior to and after the imagery phase. In some studies, researchers consult family members for corroboration²⁰; however, a majority of the research examining imagination inflation relies solely on the word of the participant.

DRM procedures offer methodological advantages over other memory paradigms, including imagination inflation procedures, because researchers maintain control over the content being activated in working memory through the design of the lists. Specifically, researchers select the list items according to their associative strength to the critical lure and can easily measure when a participant commits the targeted memory error (e.g., chair was not on the studied list but was recalled at test). This content control provides insight into processes that drive associative memory errors, affording researchers the opportunity to explore other potentially important factors driving false memory errors, such as the construction of visual images during list encoding²¹ or even elaborating on the list items to generate complex event narratives¹¹.

This protocol employs a presentation administration of materials and a paper and pencil format of data collection that allows researchers to collect participant data in large groups (e.g., classrooms), while systematically varying variables. The accessibility and experimental control offered by this protocol provides an opportunity to teach students about memory processes with an in-class demonstration while reliably collecting data. Compared to laboratory-based DRM procedures, this context makes results more applicable to classroom learning, thus informing both cognitive science and educational psychology. In addition, this protocol provides optional modifications that can be utilized to remove the usage of imagery instructions or varying list types, thereby offering a construction-kit type approach that allows for more personalized use.

Protocol

All methods described here have been approved by the Institutional Review Board of Georgia State University.

1. Material Preparation

1. Using the word lists attached in the supplemental materials, create four separate presentations: Imagery A, Imagery B, Non-imagery A, and Non-imagery B. Ensure that all four presentations are void of templates or designs, with white backgrounds and black font. The two list orders, A and B, serve to balance any effects of list order or fatigue. The two imagery versions serve to assess the effects of imagery instructions on memory.
   1. Begin each presentation with a content slide titled, "Instructions". In the body of the instructions slide, include the relevant instructions listed below in 24+ point font according to whether the presentation is designated as imagery or non-imagery.
      1. Include these instructions for Imagery A and Imagery B presentations: "I will present words from a list, one at a time, on the projector. As each word is presented, please create a mental image of that word in your mind. Please do not mark on the packet while the list is being presented. When each list is finished, the projector will indicate, "RECALL", and you will write down the words you remember from the list in the packet provided. Try to use the images you created to help you recall the words. After you have written down all the words that you can remember, please indicate overall how easy it was for you to create mental images for that list. You will be given 45 seconds to recall the list and rate the ease of creating images, and then we will move on to the next list. When we do so, please flip to the next page in the packet. It is important that you do not revisit any old lists once we have moved on. There will be 11 lists in total, the first being a practice list. After all the lists have been presented, you will be asked to complete a word search task."
      2. Include these instructions for Non-imagery A and Non-imagery B presentations: "I will present words from a list, one at a time, on the projector. Pay attention to the words on the projector. Please do not mark on your packet as the words are being presented. When each list is finished, the projector will indicate "RECALL", and you will write down the words you remember from the list in the packet provided. You will be given 45 seconds to recall as many words from the list as you can, then we will move on to the next list. When we do so, please flip to the next page in the packet. It is important that you do not revisit any old lists once we have moved on. There will be 11 lists in total, the first being a practice list. After all the lists have been presented, you will be asked to complete a word search task."
   2. Following the instructional slide, create timed slides to present lists and prompt recall. All text is center-aligned. List words are 72 point font, and all instructional cues are 44 pt. font.
      1. Create slide 2 and include the text "Prepare for the practice list" centered vertically and horizontally on the slide in 44 point font.
      2. On slides 3-10, present the practice list words in order, one word per slide, centered horizontally and vertically, in lower case font. Designate a slide duration of 5 seconds by going under Transitions in the menu and selecting to advance the slide after 00:05.00.
      3. On slide 11, indicate the end of the practice list and the beginning of recall. Include "End of Practice List" in black font with "RECALL" double-spaced below it in red font. Designate a slide duration of 45 seconds.
   3. After the practice list recall slide, create slides to present the test lists in the same manner.
      ​NOTE: The procedure for each list is 10 slides long. The first slide indicates "Prepare for List X". The following 8 slides include the list words in order, each on a separate slide with 5 second durations. Following the list word slides, a recall slide with a designated duration of 45 seconds indicates "End of List X" in black font with "RECALL" double-spaced beneath it in red font. Adapt the "X" in the "End of List X" text to indicate the order of the lists in that particular presentation, not the order of the lists as they are listed in the appendix. For example, the 3rd list to occur in the presentation will read "End of List 3".
   4. Ensure that the order of the lists in the slides varies according to the particular presentation . According to the numbered designations in the word lists attached to the supplemental materials, Imagery A and Non-Imagery A presentations present lists in ascending order: practice, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Imagery B and Non-imagery B presentations present lists in descending order: practice, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1.
   5. After the recall slide for the last list, ensure that slide 112 includes the following text "End of word lists. Turn to the next page in your packets and please take the next 7 minutes to work on the attached word searches." Designate a slide duration of 7 minutes.
   6. Create slide 113 to include "End of word searching. One last activity". This slide has no designated duration. Create a final slide, 114, that includes a thank you.
2. Create two different versions of recall packets, imagery and non-imagery, in a word processor. Page 1 of both versions prompts participants to write down their name, gender, age, major, or any other demographic variables of interest. Page 13 of both versions includes a word search with dimensions of 20 x 20 letters or larger. Ensure that no list or practice words occur in the word search.
   1. Ensure that pages 2-12 in the recall packets include repeated recall activity pages, which vary according to the version.
   2. Ensure that recall activity pages for the imagery version include the following instructions at the top of the page: "Instructions: Create an image of each item in your head. Use the images you created to help you recall the words." Below that, the activity page includes "Recall:" with at least ⅓ of the page following it left blank. At the bottom of the page, include the following prompt: "Overall, how easily did these images come to mind for this list? Circle one". Below the ease of imagery prompt, include the following options for participants to circle: "0 - Not easy, 1 - Somewhat easy, 2 - Very easy".
   3. Ensure that recall activity pages for the non-imagery version include the following instructions at the top of the page: "Instructions: Please recall and write down all the words you remember from the current list." Below that, the page indicates "Recall:" with no other prompts following.
3. Obtain the final recognition test from the supplementary materials and do not attach it to the recall packets. It is an individual page to be handed out separately. The final recognition test consists of 80 items total.
   1. Of the 80 items, use 30 from the lists presented on the presentation slides at the start of the study. The 30 presented items chosen for the recognition memory test are the 1st, 3rd and 7th words from each of the 10 lists presented (15 semantic items and 15 phonological items).
   2. Include each of the 10 critical lures related to the 10 presented lists (5 semantic and 5 phonological) on the test.
   3. For the additional 40 items, use the DRM lists not presented to participants, including the 1st, 3rd and 7th items from each of 10 non-presented lists (15 semantic and 15 phonological items), as well as the associated critical lure (5 semantic and 5 phonological) for each of the 10 non-presented lists. The non-presented lists are located along with the presented lists in supplementary materials.
   4. Arrange the items on the recognition memory test such that one item from each of the 10 presented lists and 10 non-presented lists appears prior to any critical lures. List items are not thematically blocked on the memory test.
   5. Ensure that instructions on the recognition test prompt participants to indicate "yes" or "no" in writing as to whether each item appeared in any of the lists presented.

2. Recruitment

1. Recruit at least four face-to-face sections of the same, or very similar, undergraduate class. If possible, recruit non-psychology classes or introductory courses that have not learned about false memory paradigms.
   1. Include all students who are enrolled in the recruited classes and have normal or corrected vision to participate.
2. Assign each class section to 1 of the 4 presentation types, distributing the number of classes assigned to each presentation type as evenly as possible and prioritizing even distribution across imagery and non-imagery presentation types.

3. Optional Modifications to Protocol

1. If the effects of imagery instructions are not of interest, modify the protocol as follows to only include one set of instructions, one type of recall packet, and shorter slide durations.
   1. Using the word lists attached in supplemental materials, create 2 separate presentations, versions A and B. Present the 10 study lists in ascending order following the practice list in the version A presentation (practice, 1, 2, 3, 4…), and present the lists in descending order following the practice list in the version B presentation (practice, 10, 9, 8, 7…).
   2. Include the non-imagery instructions from protocol item 1.1.1.2 on the first slide of both presentation versions.
   3. Modify the timed list presentation slides described in 1.1.2.2 to be 2 seconds long instead of 5 seconds. In other words, design the presentation so that each word is presented to participants for 2 seconds. Do not modify any other types of timed slides, like the recall slides (45 seconds) or word search side (7 minutes).
   4. Create 1 version of the recall packet (i.e., non-imagery version) that includes the traditional non-imagery instructions from protocol item 1.2.3.
   5. Assign the recruited classes to the 2 presentation types as evenly as possible.
2. If the effects of list type (semantic vs. phonological) are not of interest, modify the protocol as follows to only include longer, traditional semantic DRM lists:
   1. Do not use the word lists included in our supplementary materials, with the exception of the practice list. Instead, select 20 of the unmodified DRM lists included in the original Roediger & McDermott study². These word lists are 15-items long and all semantically related. Number the selected lists 1-20. Use lists 1-10 as study lists in the presentation and lists 11-20 as filler lists for the recognition test.
   2. Modify the presentations to accommodate 15-item lists instead of 8-item lists. Following the instruction slide and practice list, the procedure for each test list is 17 slides long. For each list, the first slide indicates "Prepare for List X", the following 15 slides present the list words one at a time, and the last slide for the list indicates the end of the list and the beginning of recall.
   3. Modify the recognition test design described in 1.3 to include the 1st, 8th, and 10th words from the 10 study lists and 10 filler lists and their critical lures.

4. Procedure

1. At the beginning of a regularly scheduled class session, ask the instructor to leave the room and pull up the presentation that was assigned to that class section.
2. Introduce yourself as the researcher and distribute informed consent forms to students. Allow students to read through the informed consent document on their own. Prompt them to complete the informed consent form and to ask any questions about the document or participation.
3. Distribute the appropriate recall packets to participants. If using an imagery condition, ensure that classes who were assigned one of the two imagery presentations receive an imagery recall packet. Do not distribute the recognition test yet.
4. Instruct participants to fill out the initial page of the recall packet with demographic information. Then read the instructions from the presentation aloud with the slide presented.
5. Instruct participants to flip to the next page in their packet for the practice list, move to presentation slide 3 (i.e., "Prepare for the practice list"), and read the prompt aloud. After reading the prompt, move to slide 4 and allow the presentation to progress through the timed practice list slides.
6. When the practice list recall slide expires and automatically moves to the next list prompt slide (i.e., "Prepare for list 1"), prompt participants to ask any questions they have about the procedure. Answer any questions and instruct participants to turn to the next page (pg. 3) in their packet for list 1.
7. Once all participants have turned to the next page in their booklet, read the list 1 prompt slide aloud (i.e., "Prepare for list 1") and progress to the timed list 1 word list and recall slides.
8. Continue this procedure for the 9 remaining lists, prompting participants to flip to the next page in their booklet after each recall slide expires, reading the "prepare for list X" slide aloud, and subsequently prompting the timed list slides.
9. After recall for list 10, supervise as the presentation prompts participants to turn to the next page in their packet and work on the word search for 7 minutes.
10. When the presentation automatically progresses to the final slide (i.e., "One last activity"), collect the recall packets from participants and distribute the final recognition test.
11. Instruct participants to complete the final recognition test at their own pace and to do their best not to leave any items blank. Once all participants have finished the test, collect the recognition tests and verbally debrief participants (see supplementary materials for debriefing statement).

Results

Effects of DRM Procedures on False Memories: Standard DRM Instructions without Imagery
To illustrate standard DRM procedures' ability to induce false memories, we analyzed rates of falsely remembering non-list words during recall and recognition. Table 1 reports proportions for the different types of false remembering that occurred during recall and recognition. During immediate recall, participants recalled unpresented words on 20% of the lists...

Discussion

The protocol employed in this study modified a widely used word list procedure, the Deese Roediger McDermott (DRM) paradigm, to assess the effects of associative processing with and without imagery instructions on false memories in a classroom-based procedure. The expansion to include the variables of list association type, test type, and imagery instruction implemented here afforded the ability to analyze how each of these complex factors influenced a learning context independently, as well as how they interacted, provi...

Materials

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No Materials Applicable