Gallo, D. A., McDermott, K. B., Percer, J. M., and Roediger, H. L. (2001). Modality effects in false recall and false recognition. Journal of Experimental Psychology: Learning, memory, and cognition, 27, 339-353.
** "veridical" is latin for "true-saying" **

R.E. Smith and R.R. Hunt (1998) reported that false recognition and false recall could be reduced substantially in the DRM paradigm by changing from auditory to visual presentation at study.  Maylor and Mo, on the other hand, reported that false recognition decreased following auditory presentation. Both groups appealed to differences in distinctiveness to explain their results.  So what's going on here?  Which produces more false memories, auditory presentations or visual presentations?  That's what Gallo et al. wanted to find out.

Experiment 1

Method
 

  • Twenty-four DRM lists were presented.  Half the lists were presented visually and half were presented auditorially.
  • After half of the lists, subjects did math problems for 2 minutes and for half of the lists subjects performed an immediate recall task for 2 minutes.
  • Subjects then took a recognition test after the final list that included remember/know judgments
  • A modality-judgment was given after the recognition test. In order to indicate which modality an old or a new word was presented, subjects were instructed to circle either:
    • Results

    Recall
     

  • False recall was greater after auditory presentation than after visual presentation.

    • Recognition
     

  • Auditory study or visual study did not affect recognition of list items.
  • It was also found that the false alarm rate to critical items was marginally greater after auditory presentation but the effect was quite small.
    • Experiment 2

    It looked like there was an effect of modality on false recognition in Experiment 1, but it was quite small and not quite significant.  So Experiment 2 was designed to boost the effect.  There were two main differences between Experiment 1 and Experiment 2.  First, they eliminated the intervening tasks (recall/math) and second, they blocked the list presentations so that subjects were presented with all the visual lists then all the auditory lists or with all the auditory lists then all the visual lists.

    Here are some more details

    A 2 x 2 x 2 within subjects design included the following:

    Subjects studied 24 of 36 lists. The lists were blocked: 12 presented auditorily then 12 visually or 12 visually then 12 auditorily.
    A recognition test was taken with items numbered 1-144 in columns. Next to the numbers, "old", "new", "R" (remember), "K" (know), and "G" (guess) appeared.

    Results
     

  • Basic finding is that there were more false memories following auditory study than following visual study, but this effect was moderated by a study modality X test modality interaction.
  • The interaction reflected the fact that there was an effect of study modality when subjects were tested visually but there was no effect of study modality when subjects were tested auditorily.  Hmmmmmmm...

    •  
    Experiment 3

    Experiment 3 was the same as Experiment 1 expect that a between subjects manipulation was used instead.  This is important because Schacter and colleagues have argued that the distinctiveness heuristic is used globally to decrease false recognition.  For that reason, study modality should have less of an effect in a within subjects design than in a between subjects design (Dodson & Schacter, 2001; .Schacter, Israel & Racine, 1999).

    That prediction was not supported.  Experiment 3 closely replicated the results of Experiment 2.  The effect of modality was no larger when study modality was manipulated between subjects.

    Discussion

    Results from the three experiments can be summarized as follows:

    Perhaps the biggest issue addressed by this article is the nature of the mechanism that suppresses false recognition.  As stated above, Schacter and colleagues have argued that people use a distinctiveness heuristic to suppress false memories.  The main idea behind the distinctiveness heuristic is that if your memory for targets is especially distinctive you should be less likely to accept false memories because the false memories will seem relatively sparse by comparison.  So one argument might be that visual presentations are more distinctive than auditory presentations.

    But Schacter has also argued that the distinctiveness heuristic is globally activated and so distinctiveness based patterns should not arise in within subjects designs.  According to this argument within subject designs make it difficult for subjects to implement the distinctiveness heuristic because it is no longer the case that targets as a class are distinctive.

    Gallo et al., however, found that their modality effects occurred for both within and between subjects designs.  One reason for this may be that modality of study lists was blocked such that all the items of one modality were presented first and then all the items of the other modality were presented.  This may have created two unique episodes so that at test subjects could apply different response thresholds.
     

     
    University of Arkansas
    Department of Psychology
    Graduate Program in Experimental Psychology
    Lampinen Lab
    False Memory Reading Group
    False Memory Reading Group Fall 2001