Quin M. Chrobak

Inventing stories: Forcing witnesses to fabricate entire fictitious events leads to freely reported false memories

Studies of the forced fabrication effect have shown that participant witnesses are prone to developing false memories for specific items or details that they have been forced to fabricate earlier (e.g., what type of hat someone wore). Building on these earlier findings, the present study assessed whether participants would develop false memories if forced to fabricate entire fictitious events that were more complex and extended in time and involved people, locations, and actions that they had never seen. Participants vehemently resisted fabricating these events, and false memory development over the short term (1-week recognition test) was limited. However, after 8 weeks, participants freely reported their forced fabrications nearly 50% of the time and did so even when they had correctly and publicly rejected them earlier on the 1-week recognition test. This is the first evidence that participant witnesses will freely incorporate into their eyewitness accounts entire fictitious events that they have earlier been forced to fabricate.

When Forced Fabrications Become Truth: Causal Explanations and False Memory Development

Studies of text comprehension have amply demonstrated that when reading a story, people seek to identify the causal and motivational forces that drive the interactions of characters and link events (e.g., Zwaan, Langston, & Graesser, 1995), thereby achieving explanatory coherence. In the present study we provide the first evidence that the search for explanatory coherence also plays a role in the memory errors that result from suggestive forensic interviews. Using a forced fabrication paradigm (e.g., Chrobak & Zaragoza, 2008), we conducted 3 experiments to test the hypothesis that false memory development is a function of the explanatory role these forced fabrications served (the explanatory role hypothesis). In support of this hypothesis, participants were more likely to subsequently freely report (Experiment 1) and falsely assent to (Experiment 2) their forced fabrications when they helped to provide a causal explanation for a witnessed outcome than when they did not serve this explanatory role. Participants were also less likely to report their forced fabrications when their explanatory strength had been reduced by the presence of an alternative explanation that could explain the same outcome as their fabrication (Experiment 3). These findings extend prior research on narrative and event comprehension processes by showing that the search for explanatory coherence can continue for weeks after the witnessed event is initially perceived, such that causally relevant misinformation from subsequent interviews is, over time, incorporated into memory for the earlier witnessed event.

The Impact of Multifaceted Questions on Eyewitness Accuracy Following Forced Fabrication Interviews

ABSTRACT Lawyers will frequently use complex-question forms, such as multifaceted questions (single questions that contain both a true and a false proposition), when cross-examining witnesses, and prior research has shown that use of such questions reduces testimonial accuracy. The present study extends this research by using a forced fabrication paradigm (Chrobak & Zaragoza, 2008) to assess how multifaceted questions might affect eyewitness suggestibility after exposure to misleading post-event information. Consistent with prior studies, the use of multifaceted questions led to lower accuracy than simple questions. The novel finding was that multifaceted questions caused larger impairments in performance among fabrication participants (who had earlier been suggestively interviewed), than in control participants (who had not). We also provide preliminary evidence that the impairment caused by multifaceted questions is due to both (a) having to consider two propositions simultaneously, and (b) the shift in question focus from the fabricated event to a true event.

Shared Processing of Language and Music

The present study sought to explore whether musical information is processed by the phonological loop component of the working memory model of immediate memory. Original instantiations of this model primarily focused on the processing of linguistic information. However, the model was less clear about how acoustic information lacking phonological qualities is actively processed. Although previous research has generally supported shared processing of phonological and musical information, these studies were limited as a result of a number of methodological concerns (e.g., the use of simple tones as musical stimuli). In order to further investigate this issue, an auditory interference task was employed. Specifically, participants heard an initial stimulus (musical or linguistic) followed by an intervening stimulus (musical, linguistic, or silence) and were then asked to indicate whether a final test stimulus was the same as or different from the initial stimulus. Results indicated that mismatched interference conditions (i.e., musical – linguistic; linguistic – musical) resulted in greater interference than silence conditions, with matched interference conditions producing the greatest interference. Overall, these results suggest that processing of linguistic and musical information draws on at least some of the same cognitive resources.

Mechanisms of eyewitness suggestibility: tests of the explanatory role hypothesis

In a recent paper, Chrobak and Zaragoza (Journal of Experimental Psychology: General, 142(3), 827–844, 2013) proposed the explanatory role hypothesis, which posits that the likelihood of developing false memories for post-event suggestions is a function of the explanatory function the suggestion serves. In support of this hypothesis, they provided evidence that participant-witnesses were especially likely to develop false memories for their forced fabrications when their fabrications helped to explain outcomes they had witnessed. In three experiments, we test the generality of the explanatory role hypothesis as a mechanism of eyewitness suggestibility by assessing whether this hypothesis can predict suggestibility errors in (a) situations where the post-event suggestions are provided by the experimenter (as opposed to fabricated by the participant), and (b) across a variety of memory measures and measures of recollective experience. In support of the explanatory role hypothesis, participants were more likely to subsequently freely report (E1) and recollect the suggestions as part of the witnessed event (E2, source test) when the post-event suggestion helped to provide a causal explanation for a witnessed outcome than when it did not serve this explanatory role. Participants were also less likely to recollect the suggestions as part of the witnessed event (on measures of subjective experience) when their explanatory strength had been reduced by the presence of an alternative explanation that could explain the same outcome (E3, source test + warning). Collectively, the results provide strong evidence that the search for explanatory coherence influences people’s tendency to misremember witnessing events that were only suggested to them.

The impact of outcome valence on the susceptibility to suggestion for post-event causal misinformation

ABSTRACT Recent research has demonstrated that people are especially susceptible to false memory development for suggested misinformation that fills a causal role (i.e., explains some known outcome) (Chrobak & Zaragoza, 2013). However, little is known about how factors associated with the witnessed outcome impact the likelihood of false memory development. In the present study, outcome valence (negative, positive, or neutral) was manipulated. Participants heard several short stories that contained an outcome (e.g., a counselor getting promoted) that lacked a causal explanation. Participants were subsequently exposed to suggested causal misinformation that explained that outcome (e.g., the counselor performed an impressive act the previous day) and then were tested on their memory for the original event. Results indicated that participants incorrectly reported the suggested causal information more when it explained either a positive or negative outcome as opposed to a neutral outcome. Theoretical and practical implications of these findings are discussed.

Analyzing Confabulations in Schizophrenia and Healthy Participants.

OBJECTIVES Confabulations occur in schizophrenia and certain severe neuropsychiatric conditions, and to a lesser degree in healthy individuals. The present study used a forced confabulation paradigm to assess differences in confabulation between schizophrenia patients and healthy controls. METHODS Schizophrenia patients (n=60) and healthy control participants (n=19) were shown a video with missing segments, asked to fill in the gaps with speculations, and tested on their memory for the story. Cognitive functions and severity of symptoms were also evaluated. RESULTS Schizophrenia patients generated significantly more confabulations than healthy control participants and had a greater tendency to generate confabulations that were related to each other. Schizophrenic confabulations were positively associated with temporal context confusions and formal thought disorder, and negatively with delusions. CONCLUSIONS Our findings show that the schizophrenia patients generate more confabulations than healthy controls and schizophrenic confabulations are associated with positive symptoms. (JINS, 2016, 22, 911-919).