Ayanna K. Thomas

Creating bizarre false memories through imagination

The present study explored memory for familiar or usual actions (e.g., flip the coin) and bizarre or unusual actions (e.g., sit on the dice). In Session l, action statements were presented to 210 participants, who had to either perform or imagine those actions. In Session 2, 24 h later, participants imagined performing various actions, some presented in the first session and others totally new. Finally, in Session 3, 2 weeks later, participants were tested on their memory for the original actions. We found that as the number of imaginings increased in Session 2, so did the proportion ofdid responses to actions that were only imagined or not even presented. This pattern was present for both bizarre and familiar actions. These results demonstrate that bizarre actions may lose the item distinctiveness that is used to make accurate memory decisions after repeated imagination.

Recalling a Witnessed Event Increases Eyewitness Suggestibility The Reversed Testing Effect

Peoples later memory of an event can be altered by exposure to misinformation about that event. The typical misinformation paradigm, however, does not include a recall test prior to the introduction of misinformation, contrary to what real-life eyewitnesses encounter when they report to a 911 operator or crime-scene officer. Because retrieval is a powerful memory enhancer (the testing effect), recalling a witnessed event prior to receiving misinformation about it should reduce eyewitness suggestibility. We show, however, that immediate cued recall actually exacerbates the later misinformation effect for both younger and older adults. The reversed testing effect we observed was based on two mechanisms: First, immediate cued recall enhanced learning of the misinformation; second, the initially recalled details became particularly susceptible to interference from later misinformation, a finding suggesting that even human episodic memory may undergo a reconsolidation process. These results show that real-life eyewitness memory may be even more susceptible to misinformation than is currently envisioned.

Exploring the role of repetition and sensory elaboration in the imagination inflation effect

Two experiments were conducted to examine whether a misattribution of specific characteristics or a misattribution of global familiarity underlies false memories as assessed through imagination inflation. Using the paradigm developed by Goff and Roediger (1998), we found that the proportion of false memories increased with repeated imagination, replicating the imagination inflation effect. False memories developed through imagination were greatest in conditions that forced participants to include sensory detail in their imaginings. Finally, conscious recollection more often accompanied false memories in perceptually detailed imagination conditions, whereas feelings of familiarity more often accompanied false memories in conditions that lacked sensory cues. These results suggest that imagination that contains more perceptual information leads to more elaborate memory representations containing specific characteristics that can be confused with actually performed actions. Confusion based on these representations, as opposed to confusion based on processing fluency, is more likely to lead to false memories.

Virtual Reality Monitoring: Phenomenal Characteristics of Real, Virtual, and False Memories

This study explored virtual-reality (VR) monitoring, the decision process by which people discriminate memories of real and virtual events. In a study phase, subjects touched 10 real objects with their real finger and touched 10 virtual objects (visual only, no tactile feedback) with their cyberfinger in VR. One week later they took a real versus virtual versus new source identification test. After the source identification test, subjects rated phenomenal qualities associated with each memory, using a Virtual-Real Memory Characteristics Questionnaire (VRMCQ). For old items, results from the VRMCQ are consistent with the idea that VR monitoring draws on differences in qualitative characteristics of memories for perceived and virtual events/objects (consistent with Johnson and Raye). However, subjects also reported similar qualities associated with their false memories for new items, suggesting that they sometimes infer/reconstruct the qualities a memory should have, based on their decision of its source of origin. Furthermore, VR monitoring might prove useful as a sort of Turing test of how convincing the virtual world is, and the VRMCQ can identify which qualities of the virtual experience (e.g., color) require improvement. Examples of applications are discussed.

The negative cascade of incongruent generative study-test processing in memory and metacomprehension

Previous research suggests that when participants engage in generative study activities, the processing of text is enhanced and improvements in memory and metacomprehension result. However, few studies have investigated the influence of processes required by the testing situation or the interaction between encoding and retrieval processes on metacomprehension accuracy. The present experiments examine whether the congruency of processes generated during study and required at retrieval affect memory, metacomprehension, and control processes. Study orientation and test type were congruent (i.e., letter-reinsertion: detailed test), incongruent (i.e., letter-reinsertion: conceptual test), or neutral (i.e., read: conceptual test). After generative study, but before testing, participants made metacomprehension predictions for previously studied texts. Controlled strategy selection was measured in Experiment 2. When processes at study and test were congruent, cued recall performance and metacomprehension predictions were more accurate than when study and test were incongruent. For incongruent conditions, metacomprehension predictions were no better than chance; thus, controlled strategy selection was based on inaccurate metacomprehension, thereby further penalizing memory performance relative to congruent conditions. These findings extend a transfer-appropriate processing framework to metacomprehension.

Children's memory for trauma and positive experiences

Characteristics of childrens memory for a trauma and for a positive event were compared and relationships of memory characteristics to trauma symptoms examined in 30 children who experienced a traumatic event. Results revealed that memories for trauma tended to have less sensory detail and coherence, yet have more meaning and impact than did memories for positive experiences. Sexual traumas, offender relationship, and perceived life threat were associated with memory characteristics. Few relationships between memory characteristics and trauma symptoms were found. Therapist ratings of child memory characteristics were correlated with some child trauma memory characteristic reports. These results are consistent with other studies. Possible explanations include divided attention during the traumatic event and cognitive avoidance occurring after the event.

Effective cue utilization reduces memory errors in older adults.

When compared with younger adults, older adults typically manifest poorer episodic memory. One hypothesis for the episodic memory deficit is that older adults may not encode contextual information as well as younger adults. Alternatively, older adults may use contextual information at retrieval less effectively when compared with younger adults. If older adults encode context less well than younger adults, then manipulations that affect context should have little effect on memory performance. To evaluate these 2 hypotheses, the authors used manipulations that promoted effective contextual cue utilization at retrieval. Retention interval and instructions at retrieval were manipulated within the imagination inflation paradigm. Results suggest that older adults encode contextual cues useful in improving memory performance but have difficulty accessing and using those cues.

Context Affects Feeling-of-Knowing Accuracy in Younger and Older Adults.

In feeling of knowing (FOK) studies, participants predict subsequent recognition memory performance on items that were initially encoded but that cannot presently be recalled. Research suggests that FOK judgment magnitude may be influenced by the total amount, or quantity, of contextual information retrieved related to the unrecalled target (e.g., Koriat, 1993). The present study examined the contribution of quality of that information to episodic FOK judgments. In addition, we tested whether the episodic FOK deficit demonstrated by older adults could be reduced by encouraging retrieval of contextual information relevant to the target. Three experiments demonstrated that quality of the retrieved partial information influenced FOK judgments in both older and younger adults; however, the manifestation of that influence was age dependent. The results also indicated that older adults required explicit retrieval of contextual information before making FOK judgments in order to make accurate FOK predictions. The results suggest that FOK accuracy may be partially determined by search processes triggered when participants are queried for contextual information.

Metacomprehension for Educationally Relevant Materials: Dramatic Effects of Encoding-Retrieval Interactions

As the metacomprehension literature has grown, important discoveries pertinent to education have been made. For example, as students are better able to assess their knowledge and implement appropriate study strategies, presumably their acquisition and retention of course material improves. Accordingly, we consider the metacomprehension literature with an emphasis on factors that impact metacomprehension accuracy. Several studies have demonstrated that metacomprehension prediction accuracy will improve to the extent that people engage in enriched-encoding activities. More recently, research by Thomas and McDaniel (in press) has suggested that enriched-encoding manipulations interact with retrieval to impact both retention and metacomprehension and, in turn, the effectiveness of controlling subsequent study. Thus, matching enriched-encoding activities with the criterial test plays a critical role in metacomprehension accuracy and control of studying.

Reducing the Burden of Stereotype Threat Eliminates Age Differences in Memory Distortion

An aspect of age-related stereotypes is that aging is associated with negative cognitive attributes, such as slow thinking and forgetfulness (e.g., Hummert, Garstka, Shaner, & Strahm, 1994). Activation of these stereotypes has been shown to negatively affect memory in older adults. In contrast, previous studies have shown that deemphasizing age-related stereotypes improves older adults’ memory (Hess, Auman, Colcombe, & Rahhal, 2003; Hess, Emery, & Queen, 2009). The goal of the study reported here was to determine the effects of stereotype activation, or stereotype threat (e.g., Steele & Aronson, 1995), on false-memory susceptibility in older adults. To do this, we used the Deese-RoedigerMcDermott (DRM) paradigm, in which individuals study lists of associatively related words and then complete a memory test (Roediger & McDermott, 1995). Research suggests that older adults are more likely than younger adults to falsely remember lures related to studied words because older adults rely on relational processing rather than the more cognitively demanding item-specific processing (Thomas & Sommers, 2005). Relational processing, as compared with item-specific processing, is less likely to make individuating item information accessible at retrieval. Without this individuating information, people cannot effectively discriminate between targets and lures. In the experiment reported here, we tested the hypothesis that when threat was reduced, older adults would be more likely to retrieve information garnered from item-specific processing; this would in turn result in better discrimination among items and a decrease in susceptibility to false memories.