Variation in working memory capacity and intrusions: Differences in generation or editing?

Abstract

The current study explored the reason for the relation between individual differences in working memory capacity (WMC) and intrusions in free recall. High and low WMC individuals were tested in standard delayed free recall and externalised free recall in which participants recalled everything that came to mind. Additionally, in externalised free recall participants were instructed to press a key for each item that they knew was an intrusion. In delayed free recall, low WMC individuals recalled fewer correct items and more previous list and extralist intrusions than high WMC individuals. In externalised free recall, differences only arose in previous list intrusions. Furthermore, in externalised free recall it was found that low WMC were less likely to identify both types of intrusions than high WMC individuals. It is argued that the reason low WMC individuals recall more intrusions than high WMC in free recall is due to differences in both generation and editing abilities.

Keywords:

• Working memory
• Free recall
• False memory
• Intrusions

Acknowledgements

Thanks to Greg Spillers for comments on an earlier version of the paper.

Notes

¹Prior research has suggested that 45 s is ample time for free recall with the given list lengths for both high and low WMC individuals (Unsworth, 2007).

²Participants recalled significantly fewer items in externalised free recall compared to delayed free recall, F(1, 62) = 26.74, p<.01, perhaps due to the extra burden of having to indicate if the response was incorrect or not. This, however, did not differ as a function of WMC, F(1, 62) = 1.56, p>.21, indicating that any additional burden was the same for high and low WMC individuals.