Henkel, L.A., Franklin, N. & Johnson, M.K. (2000). Cross-modal source monitoring confusions between perceived and imagined events. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 321-335.

- Complex memories are integrations of information from a wide variety of sources. Memories also include much interpolation of data (i.e. hearing a computer being turned on = remembering a computer being turned on)

 

- Overabundance of data often leads to source-monitoring errors which in turn lead to false memories (i.e. hearing a computer being turned on in another office causes you to remember your friend turning on his computer next to you).

 

Previous research

- Loads of Johnson research (1993, 1981, 1999). Source monitoring relies on both “qualitative characteristics of memories” and also processes by which we evaluate our own memories. Source monitoring errors occur when features of memories are close to that of typical sources. So you can imagine an event and if it’s similar enough to real life events you can believe you actually perceived that event.

 

- Tons of research indicates that source monitoring errors can occur when a person is presented with similar info from other sources, internal or external. (Claim to see a lollipop when you actually saw a similar looking magnifying glass).

 

- Present experiments examine source-monitoring errors when memory features would likely be different. This has important applications in eyewitness testimony and exploration of memories in therapy.

 

Experiment 1

Method

- 52 college students tested individually

- Seven conditions ranged from “event imagined as seen and actually heard” to “event only seen”

- Events were presented on a videotape with soundtrack. Duplicate events were separated by at least 20 trials. 

- Participants told to concentrate on auditory details or visual details.

- After event, rated how well the event was depicted (poor, fair, or good)

- Name of event appeared on screen for four seconds, event took place for six seconds, three seconds to respond.

- Participants returned two days later for surprise source monitoring test.

 

Summary of Results of Experiment 1

- “Results show that info used in judging a memory’s source can accrue from other experiences with different versions of an event.” 

- Higher source monitoring error rates occurred with events both visually imagined and actually heard.

- Found that combining evidence from one actual modality (such as hearing) with evidence from another imagined modality (such as imagined vision) will lead to a person claiming that another actual target modality took place (such as actually seeing in our example)

- Experiment two tested whether more careful evaluation of memories will have an effect on the above.

 

Experiment 2

- Source monitoring proposes that judgment processes are flexible.

- Errors decrease when subjects are instructed to think about the source of information

 

Method

- 121 college students

- First day was same as in Experiment 1, but name of event only displayed for 3s instead of 4s.

- On second day, participants randomly assigned to one of three memory tests

Memory tests

1. Circle yes if you saw the event, no if you didn’t.

2. Multioption test

3. Yes or no, confidence judgement, and various features

 

 

Experiment 2 Summary of Results:

- Found significant difference between real and imagined events in MCQ tests.

 

- Supported claim that closer examination of memory events lead to less source monitoring errors.

 

General Discussion

- Why were there more false memories when an event was both visually imagined and actually heard?

1. Spontaneous visual imagery occurs upon hearing the event – spontaneous info is less likely to be attributed to imagination because imagination is thought of as a deliberate process.

 

2. People rely on a global evaluation of evidence in determining whether an event was seen. 



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