False memories and ageing : source-monitoring interventions reduce false recognition in both younger and older adults : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Clinical Psychology at Massey University, Manawatu, New Zealand
The purpose of the current research was to examine age-related differences in false recognition and attempt to establish whether these differences were best explained by the fuzzy-trace theory, source-monitoring processes (as part of the activation-monitoring theory), or sensitivity and/or criterion differences in signal detection ability. Eighty participants (40 younger adults, 16-30 years old, and 40 older adults, 75-80 years old) were randomly assigned to one of two experimental conditions. Twenty participants from each age group completed one of two versions of the Deese (1959) Roediger and McDermott (1995) false recognition task (DRM). The standard version required a simple old/new recognition judgement, while the source-monitoring version also required a source judgement. The results showed that older adults were sometimes, but not always, more prone to making false recognition errors compared to younger adults. Requiring source judgements decreased false recognition in both younger and older adults to a similar extent. Signal detection analyses showed that older adults were less sensitive than younger adults, and those in the source-monitoring condition were more conservative than those in the standard condition when making decisions about whether items were old. These and other results are discussed in terms of their implications and applications to real life false memories. As expected the results did not favour one theoretical perspective over another. Most of the results can be adequately explained by both the fuzzy-trace and activation-monitoring theory, although source-monitoring processes provided a simpler explanation of the research findings than fuzzy-trace theory or an appeal to bias and/or sensitivity differences.