This project is part of a broader program of research that attempts to understand the mechanisms by which people come to develop false eyewitness memories as a consequence of suggestive forensic interviews. One limitation of the extant eyewitness suggestibility literature is that it has focused almost exclusively on suggestive interviews involving false memory implantation. In the implantation paradigm, the witness is given misinformation about a witnessed event, and suggestibility is measured as the extent to which the witness then (or later) assents to the misinformation provided by the interviewer. However, in real-world forensic and therapeutic settings, suggestive interview practices are not restricted to situations involving the explicit provision of misinformation. Rather, in some cases interviewers attempt to elicit from witnesses accounts that support interviewers’ beliefs about what transpired. To this end, interviewers may forcibly press witnesses to describe those events interviewers believe transpired, even when witnesses cannot remember or never witnessed the events they are pressed to testify about; in other words they may be forced to fabricate.
Might witnesses eventually develop false memories for events they had earlier been forced to fabricate? Intuitively, it seems unlikely they would do so. Presumably, events that are confabulated deliberately and under duress will be remembered as mere fabrications - even over the long term. However, contrary to this intuition, we have conducted a number of studies showing – in both children and college students – that participants who were pressed to fabricate information about a witnessed event later evidenced false memories for some of the events they had earlier fabricated knowingly (Ackil & Zaragoza, 1998; Hanba & Zaragoza, 2007; Zaragoza, Payment, Ackil, Drivdahl, & Beck, 2001), a phenomenon we call the “forced fabrication effect”.
Although early studies documented false memory when participants were forced to fabricate isolated items or details, recent studies in our lab show that participants develop false memories even when forced to fabricate entire fictitious events that are extended in time, and involve people, locations and actions they never witnessed (Chrobak & Zaragoza, 2008). Given that witnesses to real-world forensic events are often asked to provide testimony about events that are much broader in scope (e.g., how a robbery in a convenience store transpired) this is a finding of both practical and theoretical import.
Current projects are focused on uncovering the cognitive mechanisms that underlie the development of false memories for forcibly fabricated events. For example, we have preliminary evidence to suggest that the fabricated information’s role in the causal sequence of witnessed events is one determinant of false memories – that is, participants are especially prone to developing false memories if the events they fabricate help to provide a causal explanation for unexplained observed events. Other studies are exploring the effects of other variables (interviewer feedback, resistance to confabulating, repeated questioning, format of questioning) on the incidence of these false memory errors.
The goal of the study is to assess behaviorally whether (1) PTSD is associated with general memory binding deficits and (2) whether such deficits are exaggerated for negative emotional information. To this end, we will use established behavioral cognitive paradigms to explore systematically the memory binding deficits associated with PTSD. We will compare PTSD patients (e.g., combat veterans, motor vehicle accident or domestic abuse victims) and age-, IQ, and SES-matched control subjects (e.g., non-PTSD trauma, non-trauma). Systematic comparisons of these groups across a range of stimuli (neutral pictures, negative non-trauma pictures, and trauma-related pictures) will inform not only our understanding of the cognitive deficits associated with PTSD, but will also give us clues as to the neural underpinnings of those deficits. The results of this pilot study will lay the groundwork for future behavioral and neuroimaging studies designed to assess how these binding deficits vary as a function of trauma history, type of trauma (e.g., acute vs. chronic) and other individual difference variables.
1998 video clip - LFM - FA 98
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