Jeffrey S. Neuschatz

Recall Accuracy and Illusory Memories: When More is Less

In two experiments it was revealed that manipulations that increased recall of studied list items also increased false recall of theme-related, critical nonpresented words. In Experiment 1 subjects listened to a series of short word lists, each containing items associatively related to a theme, while engaging in either semantic or nonsemantic processing. On an immediate free recall test semantic processors demonstrated greater correct recall as well as more illusory memories of critical nonpresented items than nonsemantic processors. In Experiment 2, the short study lists were combined to form longer lists that were presented either blocked by theme or in a random presentation order. Retention interval was also varied as participants were tested either immediately, one week after, or three weeks after the study phase. Presenting the target items in a blocked, as opposed to random, format increased recall accuracy, but this was at the expense of a higher intrusion rate for theme-consistent items. Interestingly, the level of false memories was not affected by retention interval even though typical decrements in the recall of study items were observed over time. The results of these experiments highlight the persistence of the false memory effect, as well as pointing to several factors, primarily semantic processing, that may lead to the creation of false memories. Interpretations are offered within the theoretical frameworks of source monitoring and fuzzy trace theory.

Assessing the effectiveness of warnings and the phenomenological characteristics of false memories

The phenomenology of false memories was investigated in three experiments in which participants heard two experimenters read lists of items that were related to critical nonpresented items. In Experiments 1, following a recognition memory test, participants rated the phenomenological characteristics of their memories immediately and after a 48-hour delay. False recognition was prevalent and on several dimensions participants rated their true memories as more vivid than their false memories. In Experiments 2 and 3, following the study phase, participants were warned about the phenomenological differences between true and false memories and were instructed to use this information to avoid reporting nonpresented items. This type of warning was ineffective at reducing false recall (Experiment 2) and false recognition (Experiment 3) relative to unwarned participants. Importantly, the inability of explicit warnings to impact illusory recollections demonstrates that the false memories cannot be attributed simply to a criterion shift.

Robust recollection rejection in the memory conjunction paradigm

The present research provides compelling evidence for recollection rejection in the memory conjunction paradigm. In Experiment 1, warnings provided at time of test were shown to reduce memory conjunction errors. Moreover, the authors found substantial evidence of recollection rejection and phantom recollection. In Experiment 2, the authors manipulated how often study items were presented. Participants were told that they could earn a cash payoff for being accurate. Recognition of conjunction lures was lower in the multiple presentation condition. However, the payoff manipulation did not significantly interact with item type. The authors obtained evidence of robust recollection rejection from 3 different dependent measures. Consistent with Experiment 1, they also found evidence of phantom recollection. These findings provide evidence that recollection rejection can be quite robust in the memory conjunction paradigm.

Effective warnings in the Deese-Roediger-McDermott false-memory paradigm: The role of identifiability

These experiments document that warnings can substantially reduce false memories in the Deese-Roediger-McDermott (DRM) paradigm when the critical items are easily identifiable. Participants in a norming study identified the critical item after hearing a list of words. The lists with critical items that could be identified by the largest proportion of participants (high identifiable [HI] lists) and the smallest proportion of participants (low identifiable [LI] lists) were used in the experiment. Participants heard lists of words (e.g., bed, rest, doze) related to a critical item (e.g., sleep) and were warned about the nature of the lists before the study phase. The results indicated that warnings reduced false recognition of critical items for HI lists but not LI lists.

Generative Processing and False Memories: When There Is No Cost

Encoding manipulations (e.g., levels of processing) that facilitate retention often result in greater numbers of false memories, a pattern referred to as the more is less effect (M. P. Toglia, J. S. Neuschatz, & K. A. Goodwin, 1999). The present experiments explored false memories under generative processing. In Experiments 1-3, using Deese-Roediger-McDermott (DRM) lists with items that were either read or generated, the authors found recognition and recall tests indicated generation effects for true memories but no increases in false memories (i.e., generation at no cost). In Experiment 4, in a departure from the DRM methodology, a cuing procedure resulted in a more is less pattern for congruous generation,and a no cost pattern for incongruous generation. This highlights the critical distinction between these encoding contexts.

Do Prophylactics Prevent Inflation? Post-identification Feedback and the Effectiveness of Procedures to Protect Against Confidence-inflation in Earwitnesses

After viewing or hearing a recorded simulated crime, participants were asked to identify the offender’s voice from a target-absent audio lineup. After making their voice identification, some participants were either given confirming feedback or no feedback. The feedback manipulation in experiment 1 led to higher ratings of participants’ identification certainty, as well as higher ratings on retrospective confidence reports, in both the immediate and delay groups. Earwitnesses who were asked about their identification certainty prior to the feedback manipulation (experiment 2) did not demonstrate the typical confidence-inflation associated with confirming feedback if they were questioned about the witnessing experience immediately; however, the effects returned after a week-long retention interval. The implications for the differential forgetting and internal-cues hypotheses are discussed.

The Psychology of Eyewitness Identification

1. 27 Years. 2. Theoretical Approaches to Eyewitness Identification. 3. Estimator Variables. 4. System Variables. 5. Indicia of Reliability. 6. Field Studies of Eyewitness Identification. 7. Expert Testimony. 8. Conclusions and Thoughts. 9. Philosophical Afterword: Memory and Reasonable Belief.

A Comprehensive Evaluation of Showups

The U.S. Supreme Court, state courts, and social science researchers have stated that showup identifications (one-person identifications) are less reliable than lineup identifications. Moreover, 74 % of eyewitness experts endorsed false identifications as more likely to occur from showups than lineups. Examination of the extant literature and receiver operating characteristic (ROC) analyses of over 7500 participants confirm that showups are an inferior procedure to lineups. This conclusion holds true even in situations where showups should have a memorial advantage (e.g., at a short retention interval, a clothing match between encoding and test). A signal-detection-based diagnostic-feature model provides a theoretical explanation for why showups produce inferior eyewitness performance. The data also reveal that confidence is better related to accuracy for lineups than for showups. Unless new procedural enhancements can be developed that enhance reliability, police should refrain from conducting showups in favor of lineups.

On the power of secondary confession evidence

Research on primary confessions has demonstrated that it is a powerful form of evidence. The goal of the current research was to investigate whether secondary confessions – the suspect confesses to another individual who in turn then reports the confession to the police – could be as persuasive. In Experiments 1 and 2, participants read a murder trial containing an eyewitness identification, a secondary confession, and character testimony, and made midtrial assessments of the evidence. Results indicated that the secondary confession was evaluated as the most incriminating. In Experiment 3, participants read summaries of four criminal trials, each of which contained a primary confession, a secondary confession, eyewitness identification, or none of the above. The two confession conditions produced significantly higher conviction rates. Our findings suggest that secondary confessions are another powerful and potentially dangerous form of evidence.

Hypnosis and Memory Illusions: An Investigation Using the Deese/Roediger and McDermott Paradigm

Our research used the Deese/Roediger and McDermott paradigm [1] to examine the effects of hypnosis on memory. The paradigm yielded a high rate of false recognition (>.70), regardless of whether participants were hypnotized or not. Hypnotized (N = 21) and non-hypnotized (N = 20) participants reported high false recognition rates and were very confident in their remembrances, independent of their recognition accuracy and their level of hypnotic suggestibility (medium vs. high). Although our results provide no support for the proposition that hypnosis is a viable memory enhancement procedure, hypnosis did not impair recognition above and beyond the non-hypnotic condition.