Hicks, J. L., & Marsh, R. L. (1999). Attempts to reduce the incidence of false recall with source monitoring. Journal of Experimental Psychology: Learning, Memory, and Cognition. 25, 1195 - 1209.

The general purpose of the studies contained in this article is to examine the contribution of the source monitoring process on false memories produced by the DRM paradigm.

Source Monitoring Theory: Memories contain different characteristics such as sensory, cognitive and emotional information, to name a few. These characteristics are thought to aid an individual in determining the originating source of a memory trace. A source monitoring judgement is made when a person is asked to determine the origin of a memory trace. Hicks and Marsh point out that source monitoring judgements are generally made with a higher criterion than the general recognition test. Individuals set higher criterions on source monitoring tasks because in order for them to name the source they must focus on the memory characteristics of the memory trace. In addition, source monitoring tasks take longer to complete than recognition tests.

Source monitoring tasks have been found to reduce memory bias in other areas. Hicks and Marsh are attempting to reduce the number of intrusions produced by participants completing DRM lists by including source monitoring judgements.

 

Hypothesizes

    1. Presenting items from two different source will lower rates of false alarms, because the multiple source encoding provide memory characteristics that will aid in memory decisions.
    2. Predicted that individuals that knew they would have to make source monitoring judgements immediately after free recall might implement higher response criterion and not have as many intrusions.
Experiment 1

Three groups (one source, aware group, unaware group) were presented with the sleep, needle, sweet, mountain, chair and rough DRM lists.

One source group All lists were presented orally by a male experimenter. Aware and Unaware groups For half of the lists 7 of the items on each list were presented as anagrams that participants self generated the target words by switching two letters. The other 8 items were presented orally. The other half of the lists were presented with 7 items spoken and 8 items presented as anagrams.

Participants in the aware group were warned of the source monitoring task that would take place immediately following the free recall test.

Participants in the unaware group were not warned of the source monitoring task.

 

Following the presentation of the lists participants in all groups completed a free recall test for words on the lists. Afterwards, participants in the aware condition were asked to assign a source to the memories.

At the same time in the procedure participants in the aware condition were conducting the source monitoring task participants in the unaware and one source conditions completed an arithmetic filler task. Following this task the unaware condition was read the instructions for the source monitoring task and asked to assign sources to their responses.

 

Results

 

Recall rates for targets did not vary between the three groups, participants in the aware and unaware conditions produced fewer intrusions on the free recall test. The source of the items that were falsely recalled in the aware and unaware condition was generally assigned to the verbal mode of presentation and not anagram.

 

Experiment 2a

Used the same procedure as experiment except instead of some of the items being presented as anagrams they were presented by a female speaker. Also, in the aware condition the free recall and source monitoring task were combined by having participants write their response in a male or female column. Source was measured by which column the participants wrote their responses.

Results

Participants in the one source group recalled more words than the unaware group, and the unaware group recalled more words than the aware group. Also, unlike in the first experiment, the groups did not differ on the number of intrusion errors made.

Experiment 2b

In an effort to construct a better design the Hicks and Marsh had participants in the single source condition listen to lists from two sources, funny. Half of the lists were read by a male voice and the other half were read by a female voice. Also, the source monitoring task included a third category, "not sure" of the source of the information. Finally, the unaware group was dropped from this design.

Results

Overall recall was greater for the one-source group than the aware group. Participants in the aware condition made accuarte source judgements and only made "not sure" judgement .04 of the time in each of the source conditions (male and female).

 

Experiment 3

Followed the basic design of the Experiment 1 except items were displayed visually instead of being read aloud. Therefore people either saw anagrams that needed to be corrected or enacted words to be remembered.

 

Results

Overall recall of items did not vary between the one-source and the two-source groups. However, the two-source group did produce half as many intrusion errors. This reduction was similar to the reduction in experiment. Hicks and Marsh hold that the internal and external source distinction is driving down the intrusion rate.

Experiment 4

This experiments examines the effect of having two internally generated sources. Participants decided how pleasant an item was for half of the words and the other half they decided how frequently they had encounter the word during the past several weeks.

Procedure

The procedure was identical to the procedure used for the unaware group. After, seeing the word participants rated on a scale how pleasant a word was or how frequently they had encountered the over the last few weeks. There was also a one-source group that only saw one of two directives before the item was presented on a transparency.

Results

Overall recall rates did not vary between the two groups, and the groups did not vary in levels of intrusions.


 
University of Arkansas
Department of Psychology
Lampinen Lab
False Memory Reading Group
False Memory Reading Group Summer 2000