Examining emotion specific memories: An investigation into the persistence of true and false memories

False memories occur when people recollect events that did not happen or incorrectly recollect events that did happen. In legal contexts, the inaccurate recollection of events can lead to errors in convictions. It is therefore important to establish the conditions under which false remembering can occur. When people are exposed to a crime, either as a witness or a victim, they tend to experience a negative event that has the potential to induce a negative emotion. Furthermore, there can then be a considerable delay between experiencing this negative event and recalling it during legal proceedings.

These important factors from the forensic context have only recently been examined in the false memory research. One of the most popular methods for studying false remembering in the laboratory is the Deese/Roediger-McDermott (DRM) paradigm. In this paradigm, participants study a list of words that all semantically associated (e.g., cigar, cigarette, chimney) to one nonpresented word (e.g., smoke). We refer to this word as the critical lure. On subsequent memory tests, participants often falsely recall and recognise these critical lures more frequently than the studied items. We refer to this as a false memory. Moreover, when participants are asked to make remember-know judgments to the critical lures (where a remember response indicates participants can mentally re-experience the presentation of a studied item and a know response indicates participants believe an item is familiar but cannot recollect its presentation) they typically make a remember response. The DRM paradigm can therefore produce vivid false memories.

A few experiments have studied the effect of negative emotions on false memory formation using this paradigm. Participants may be asked to study information while in a particular mood using a temporary mood induction technique. Participants may also be asked to study information that is emotionally negative or positive in content. Of particular relevance to forensic situations, research has also manipulated the delay from when the participants studies the information and then completes the memory test. However, research has yet to examine how specific emotions relevant to such forensic situations may impact on recall of specific information relevant to that emotion. We believe this could be of particular interest given that recent research shows we produce more true (and false) memories for information that matches the emotion/mood that we were experiencing at the time of study.

Furthermore, although research has shown that negative false memories increase over time, recent evidence suggests that this selective consolidation for emotional false memories may occur preferentially during sleep rather than over time per se. The explanation comes from neurochemical changes that occur during REM sleep that result in activity in brain regions that are thought to play a role in the selective consolidation of emotional stimuli. The role of sleep consolidation on the formation of negative emotional false memories has yet to be examined.

The series of experiments outlined in this proposal will further examine these factors (specific emotions elicited during these events and the time and type of delay between encoding and retrieval of the event) that have the potential to mediate the degree to which people falsely remember emotion relevant information.

Impact will primarily come from the increased understanding of the effects of emotion and retention on false memory formation that this research will provide. Researchers and practicing professionals in forensic contexts will benefit most from these findings. For example, lawyers, judges and jurors, will find that the output from this research will facilitate them in understanding the impact specific emotions may have on recollection of events for statements or trials, and how consolidation through delay in recall will influence that recollection. These findings therefore help in the assessment of memory reliability. Although extensive research examining the formation of false memories has been available to such professions and the legal system, few studies have examined the emotional arousal experienced at the time of encoding, the effect this will have on recall of emotion relevant information, and consolidation of true and false memories that may occur over a period of delay. This series of experiments will consider how specific emotions influence false memories and the importance this has to our understanding of the development of false memories in a forensic context.

Outcomes from this research will also be of interest and impact upon the general public. A number of high-publicity cases based on allegations made against high-profile figures have increased public interest on issues surrounding memory and the law. However assessment of memory reliability and fallibility is still misunderstood. It is the hope that the findings of such research will make the general public more aware of memory reliability issues surrounding allegations and eyewitness accounts in the forensic context.