The Effect of Stress on the Development of False Memory and Forgetting Sarah Vogt, Ashley Recker, and Russalyn Spicer Hanover College

Introduction: What is False Memory? “…Memories of experiences that never occurred” (Conway, 1997, p. 184). In contrast with true memories, they are often associated with weak or vague images Why we develop them: Initial interpretation inaccurate Power of suggestion: fill in gaps over time

Implications for Eyewitness Testimony Innocence Project (Roots, 2001) 15 out of 70 cases involved false witness testimony Exonerated 146 convicts, 13 on death row Why is it important? Be skeptical of witness testimony

Stress and False Memories Experimentally induced stress Payne, Nadel, Allen, Thomas, and Jacobs (2002) Stress and no-stress conditions Related and non-related lure words More related words “recalled” in stress condition

Stress and Its Effect on Forgetting Conflicting findings Some studies found either no effects or interfering effects of stress on memory Others suggest that more stress = higher levels of recall (Goodman, Hirschman, Hepps & Rudy, 1991)

Stress and Its Effect on Forgetting Lindberg, Jones, McComas, Collard & Stuart, 2001 Young Children Witnessed or Experienced Inoculations Stress measured by subjective pain of inoculation Findings: Those who experienced the stress had more stressor-related memories and greater resistance to forgetting over time. Those who only witnessed the stressor had greater memories of non-stressor related details.

Hypotheses An increase in stress level is expected to result in an increase in the number of false memories An increase in stress level is expected to result in an increase in forgotten details

Participants N = 13 3 Males/ 10 Females Ages All Caucasian Small, Midwestern liberal arts college

Procedure: Overview Informed Consent Dual Task Experiment Difficulty level high Difficulty level low Watched video clip (approx 1 minute) Memory Task (questionnaire) Debriefing

Dual Task Stimulus 10 trials each No practice condition Stressful Increased speed of dot (25) Smaller box size (25) Not stressful Decreased speed of dot (2) Large box size (50)

The Video Clip 1 minute, 4 seconds Late at night Woman witnesses crime from window Assault/ attempted murder Male perpetrator Female victim Perpetrator runs away

The Memory Task Post-video questionnaire 9 sections e.g. “What did the perpetrator look like?” Checklist format How it was coded: # of false memories = # marked incorrect # forgotten details = # correct left unchecked Totals for both false memories and forgotten details recorded

Sample Question  Wallet  Purse  Car  Hedges  Robe  Underwear  Watch  Lamp post  Police officer  Blood  Check all that you remember seeing (Check all that apply.):

Results False Memories t (11)= , p = 0.84 Stress M = 5.71; No Stress M = 6.00 Forgotten Details t (11)= 1.04, p = 0.32 Stress M = 12.00; No Stress M =10.50 Example: Participant “saw” a wallet and crime was a “mugging”

Discussion/Limitations What does it all mean Limitations Dual-task as stressor Questionnaire Format Participant interest

Future Directions Pre-study anxiety scale Anxiety scale after dual task Dual task with video Type of video Length Quality Vary elapsed time before questionnaire Multiple questionnaires

Questions?