Overdistribution in False Memory

There are two kinds of memory errors: forgetting errors and false memory errors. Forgetting errors are when a person cannot remember an event while false memory errors are when a person falsely remembers something. In the case of a false memory error, the true memory state is rejected. Recently, it has been proposed that there is a third kind of false memory error, called overdistribution, where you have both memory traces consistent with the false memory and you also have memory traces consistent with the true memory, and which memory you accept is dependent on what you are asked. Overdistribution has been found to make up a good proportion of “false memory” responses and several studies in the lab are focused on utilizing distractor words to investigate the difference between semantic and phonological false memory errors, immediate memory processes, and the relationship between various question probes.

Eye-Witness Misidentification

Eyewitness misidentifications were involved in 70% of the DNA exonerated wrongful convictions in the United States (Innocence Project, 2018).  It has been found that misidentifications are often paired with high witness confidence and as a result the predictive value of confidence ratings on eyewitness accuracy has been called into question. Previous research has found, however, that confidence ratings can be highly predictive of accuracy in certain conditions.  The aim of the current study is to try to better understand what makes confidence predictive of accuracy in some conditions, but not in others.

Reward and Emotion

Both the emotional contents embedded in the study materials and the reward values accompanying the study materials have been shown to influence memory performance.  Recently, another variable that has long been overlooked, emotional ambiguity, has been proposed to have a potential effect on cognitive performance (e.g., Brainerd, 2018; Mattek, Wolford, & Whalen, 2017).  In this study, we factorially manipulate reward values, emotional contents and emotional ambiguity in the study words during encoding.  We also implemented the dual-retrieval models to pinpoint the verbatim and gist retrieval processes that are responsible for the effects of emotion and reward.

Hybrid DRM

Accumulating evidence has suggested that phonological and semantic DRM lists can both elicit high levels of false memory.  Moreover, the mixture of the two – hybrid lists, can elicited over-additive false memory compared to pure semantic or pure phonological lists (Watson, Balota, & Roediger, 2003).  However, it is unclear whether the list composition, namely the proportion of phonological and semantic associates on the DRM lists, will make a difference in terms of false memory.  In this study, we manipulated different list compositions during encoding, and used both immediate and delayed recognition tests during retrieval.  The conjoint recognition test was implemented so we can identify the retrieval processes affecting memory performance for the list words.