The false memory experiment

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PSY3002_Cognitive Lab
© 2009 South University

False Memory Experiment: Evaluation Categories

Your experimental results (percent recall) are divided into the following three main categories:

• Original List: The words appearing in the list

• Normal Distracter: The words not appearing in the list and also not related to the other
words in the list

• Special Distracter: The words not appearing in the list but related to the other words in
the original list

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PSY3002_Cognitive Lab
© 2009 South University

False Memories

Elizabeth Loftus of the University of California, Irvine, is well known for her extensive research
into eyewitness memory and false memories. In her words, “You fill in the holes every time you
reconstruct an event in your own mind.” Let’s examine two of her experiments on false memory.

Experiment 1

In this experiment, the participants were presented with a series of color slides that depicted
successive stages in an accident involving a car and a pedestrian. The car was a red Datsun
traveling along a side street toward an intersection.

The participants were divided into two groups. During the presentation, Group 1 was shown a
slide on which the car had stopped at a “stop” sign before hitting the pedestrian walking on the
crosswalk. Group 2 was shown a slide on which the car passed a “yield” sign before hitting the
pedestrian.

Immediately after viewing the slides, the participants were asked several questions, one of which
was critical to test their recall of the accident. The people in Group 1 were asked whether they
saw another car passing the red Datsun when it stopped at the stop sign. The people in Group 2
were asked whether they saw another car passing the red Datsun when it stopped at the yield
sign.

After completing the questionnaire, the participants were given a break of one to two hours.
During this break, they were asked to read an unrelated short story and answer questions based
on the story.

Pairs of slides of the accident were again shown to the participants, and they had to indicate
which slide of each pair they had seen before. The critical pair was the slide depicting the Datsun
near a stop sign and a nearly identical slide depicting the Datsun near a yield sign.

Results indicated that when the question contained consistent information, 75 percent of the
participants responded accurately. However, when the question contained misleading
information, only 41 percent of the participants responded accurately. It was observed that in a
condition where participants were making a guess, there was a 50 percent probability of them
answering the question accurately; however, misleading questions drastically reduced their
chances of accuracy.

Source: Loftus, E. F. (1996). Eyewitness testimony: With a new preface. London: Harvard

University Press. Retrieved August 20, 2009, from
http://www.softdevlabs.com/personal/Eyewitness_Testimony/Eyewitness_Testimony.
html

Experiment 2

In this experiment, participants were asked to recall events that happened in their childhood or
events about which they had heard from their parents, siblings, or relatives. The experiments took
place in two phases.

In Phase l, participants read a booklet containing four short stories about events from their
childhood, provided by their parents, siblings, or other older relatives. Three events actually
happened and the fourth event was false. The false event talked about how the participant had
got lost in a mall when he or she was a child. The events were described in a single paragraph.

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PSY3002_Cognitive Lab
© 2009 South University

The false event was constructed around outlets where the family shopped when the participant
was about five years old, members of the family who usually went along on shopping trips, and
kinds of stores that the participant was attracted to—special interest (after verifying that the
participant had not got lost in a mall around the age of five years).

Participants completed their booklets by reading what their relatives had recited about each of the
four events and then writing what they remembered about each event.

When the participants returned the booklets, they were called for two interviews to be held after
an interval of one to two weeks. The participants were informed that they were being examined
based on how much detail they could remember and how their memories were as compared to
those of their relatives and parents. Twenty-five percent of the twenty-four participants recalled
having been lost in a mall, and some participants even described the event in detail even though
the event had never occurred in their childhood.

Source: Loftus, E. F., & Pickrell, J. E. (1995). The formation of false memories. Psychiatric

Annals, 25(12), 720–724.