Autobiographical Memory Conjunction Errors: Factors Influencing Memory Accuracy

Abstract

It has long been recognised that episodic memory representations are stored as constituent features distributed widely across the brain, and that retrieval of a coherent episode requires these fragments to be relocated, reactivated and reintegrated. This reconstructive memory system is subject to a range of distortions, including erroneous incorporation of features from one memory into another, forming what are known as memory conjunction errors. Factors influencing the generation of conjunction errors in autobiographical memory (AM) have thus far received little empirical attention. Understanding the nature of AM conjunction errors affords us the opportunity to identify the circumstances that may facilitate the occurrence of these errors, particularly in situations where memory authenticity is of high priority, such as eyewitness testimony. The studies in this thesis illuminate several factors influencing the prevalence of AM conjunction errors. Study 1 demonstrates an imagination inflation effect for AM conjunction errors, whereby generating a highly vivid and plausible simulation at encoding increases the likelihood of a conjunction error later forming. Study 2 further reveals that the subjective and objective qualities of conjunction events at retrieval are similar to those of authentic memories, in line with a source monitoring account of false memories. In Studies 3 and 4 the cognitive processes underlying AM conjunction error formation were evaluated through the lens of healthy aging. Study 3 extends findings of an age-related increase in conjunction errors for simple laboratory stimuli to distinctive and personally-relevant AMs. Study 4 further demonstrates that declines in inhibition ability may underlie the increased rates of AM conjunction errors with age, and can account for some of the individual variation in conjunction error susceptibility in younger adults. These findings speak towards an overreliance on the familiarity garnered by the individual components of a conjunction lure, as well as a phenomenological dedifferentiation of conjunction events and veridical memories, as contributing to the formation of AM conjunction errors. This research expands our knowledge of the types of memory distortions to which the constructive memory system is prone, and also elucidates some of the mechanisms by which these errors are misattributed as reality.