Induced-forgetting Phase

Individual sets of memories were then prepared according to DF-item, DF-list, or RIF procedures using a power point presentation format in 24 or 28 font so that the presentation of memories fit the width of the screen on no more than two lines. Participants provided the researcher with their individualized code from Phase 1 and then, the corresponding power point presentation was presented. Prior to presentation of the induced-forgetting paradigm, informed consent from Phase 1 of the present study was reviewed. Participants then completed a measure of depressive symptoms (CES-D) at the beginning of the second phase followed by measures of sadness and general negative and positive mood (PANAS). Participants were then engaged in one of three

induced-forgetting procedures.

In all conditions participants were told that they would be shown combinations of the cue word – personal word – and memory exemplar on a

computer screen (e.g., “illness”- “food” – “I got food poisoning”). These combinations were an individualized list of the personal negative memories elicited by the same participants from phase 1. An additional 8 non-memory combinations were added as filler items designed to control for the primacy and recency effects that typically occur in recall tasks (Ashcroft, 2006). Filler items were taken from the demographic questionnaire.

Combinations (e.g., “illness”- “food” – “I got food poisoning”) were presented on a 19-inch flat screen computer monitor in a quiet laboratory. The following instructions were provided to each participant in the RIF paradigm:

You will now be presented with the cue – personal word – memory exemplar pairings elicited during the previous phase of the study. The pairings will appear and remain on screen for 10 seconds, followed by a blank screen for 2 seconds.

Your task is to study these pairings and attempt to form a connection between the cue, personal word and memory exemplar. Any Questions? As each pairing appears on the screen, I will read it out loud. Try to form a connection in your mind.

After completion of the presented list of combinations for study, participants in the RIF paradigm condition engaged in retrieval-practice.

Individuals were told that they would be presented with some of the memory cue-personal exemplar pairs and would be asked to retrieve (say out loud) the correct personal memory example (e.g., “illness” – “food” – “????”). This

retrieval practice process continued for three consecutive trials (all participants

demonstrated 100 percent accuracy in retrieval on the first trial and on all subsequent trials).

The portion of the list selected for retrieval practice for RIF was generated based on previous ratings of negativity obtained during phase 1 to ensure even distribution of negativity, clarity, and age of memory across Rp+, RP-, and NRP categories. Participants were given 12 seconds from the time each item appeared on the screen to report the correct memory before the next category cue-personal exemplar pair appeared. The participant indicated that the correct exemplar had been retrieved by saying “yes” at which time the experimenter asked for the memory phrase. Participants continued for three retrieval-practice trials. After completing the RIF retrieval practice, participants were given the distractor task (see Appendix L) in which they were asked to spend the next three minutes crossing out all of the vowels in a visual search task. Finally, the cue words were presented on screen, randomly one at a time, and participants were asked to recall (write down) all the personal words and memory exemplars associated with each cue. Primacy and recency were also controlled by presenting 4 filler cues at the beginning of the recall task followed by the target cue words, followed again by 4 filler cues. Each word was presented on the screen and remained for 60 seconds at which time a bell sounded indicating that the next cue word had appeared.

For participants in the DF-item paradigm, the following instructions were given:

You will now be presented with the cue – personal word – memory exemplar pairings elicited during your last visit. The pairings will appear and remain on screen for 10 seconds. After each pairing you will be instructed to either

REMEMBER or FORGET the pairings you just saw. The word REMEMBER or FORGET will appear on the screen following each pairing presentation. If a FORGET cue appears then you should forget those pairings but if a

REMEMBER cue appears you will need to remember the pairings for a test of recall at the end of the experiment. Any Questions? As each pairing appears on the screen, I will read it out loud.

Each DF-item combination (e.g., “illness”- “food” – “I got food poisoning) appeared for 10 seconds and was then followed by a cue to either “forget” or

“remember.” The “forget” or “remember” instruction remained on the screen for 2 seconds before the next combination appeared. Participants were then given a filler task (visual letter search; see Appendix L) for three minutes. Upon

completion of the filler task, participants were then given a sheet of paper and told that the cue words would now be presented on the screen one at a time and they were to provide all of the personal word-memory exemplar pairs associated with each cue word that they could remember regardless of whether they were previously told to remember or forget. The cued recall task was the same as for the RIF procedure outlined previously.

The procedure for the DF-list method was similar to the DF-item method with one exception. The initial instructions were as follows:

You will now be presented with the cue–personal word–memory pairings that were elicited during your last visit. Your task is to study the pairings so that you can remember as many as possible. The pairings will appear and remain on screen for 10 seconds, followed by a blank screen for 2 seconds. Any Questions? As each pairing appears on the screen, I will read it out loud.

After a block of 16 pairings were presented the researcher was prompted to give the following instruction when a blank screen appeared with a small x in the bottom right hand corner of the screen:

I am sorry but I just realized that I gave you the wrong list of pairings to study!

Forget that list. I’ll start a new list that is the one you are suppose to remember. I’m so sorry for all your work. Forget what you saw and try now to remember this next list of pairings.

The cued-recall procedure was the same as for the DF-item method. For all induced-forgetting paradigms, each cue word was presented one at a time on the computer screen for 60 seconds. Participants were asked to write down all personal words and memories that they could regardless of any previous instructions to remember or forget (in the case of DF paradigms). A chime sounded to indicate that the next cue word appeared. Participants were

instructed to take their best guess if unsure that a specific person word-memory matched a given cue word. Participants then completed post measures of

positive and negative affect (PANAS) and the single item mood measure for sadness.

Further, all participants completed the self-report measures of mental control (CUTS, TCQ, RSS). All self-report measures were presented in a packet in which the order of presentation was randomized to control for possible order effects. In addition, half of the participants completed the measures before the forgetting task and half completed the measures after the induced-forgetting task and all post mood measures. Finally, when participants had completed the study, they were thanked for their participation, debriefed verbally and given a written debriefing form (see Appendix M) to take with them.

CHAPTER 3: RESULTS