Postulates for revising BDI structures

The process of rationally revising beliefs in the light of new information is a topic of great importance and long-standing interest in artificial intelligence. Moreover, significant progress has been made in understanding the philosophical, logical, and computational foundations of belief revision. However, very little research has been reported with respect to the revision of other mental states, most notably propositional attitudes such as desires and intentions. In this paper, we present a first attempt to formulate a general framework for understanding the revision of mental states. We develop an abstract belief-desire-intention model of agents, and introduce a notion of rationality for this model. We then present a series of formal postulates characterizing the processes of adding beliefs, desires, and intentions, updating costs and values, and removing beliefs, desires, and intentions. We also investigate the computational complexity of several problems involving the abstract model and comment on algorithms for revision.     

Imagination equally influences false memories of high and low plausibility events

To examine the effects of event plausibility on people's false beliefs and memories for imagined childhood events, subjects took part in a three‐stage procedure. First, subjects rated how confident they were that they had experienced certain childhood events. They also rated their memories of the events. Second, 1 week later, subjects imagined one high, one moderate and one low plausibility event. Third, 1 week later (and 2 weeks after their initial ratings), subjects rated their confidence and memory a second time. Imagining the events made subjects more confident that they were genuine experiences and gave subjects clearer and more complete memories. Plausibility did not affect subjects' confidence but it did affect their memories. Subjects developed clearer and more complete memories for high, followed by moderate, followed by low plausibility events regardless of whether those events were imagined. We use a nested model of plausibility, belief and memory to discuss our findings. Copyright © 2008 John Wiley & Sons, Ltd.     

Using source cues and familiarity cues to resist imagination inflation

To investigate whether people can resist imagination inflation--the imagination-induced increased confidence that fictitious childhood events really happened--we gave them different types of cues. In a three-stage procedure, participants: (1) rated their confidence that a list of childhood events had happened to them, (2) imagined some of these events, and (3) made confidence ratings a second time. Subjects received either no cues about the source of the imagined event, an additional source cue (perspective), an additional familiarity cue (a plausibility questionnaire), or both cues. Only subjects who had both types of cues resisted imagination inflation. These results suggest that additional cues can sometimes safeguard people from becoming more confident that fictitious events were genuine experiences.     

The Effects of Practice on Children's Ability to Apply Ground Rules in a Narrative Interview

Despite the widespread use of ground rules in forensic interview guidelines, it is unknown whether children retain and apply these rules throughout narrative interviews. We evaluated the capacity of 260 five- to nine-year-olds to utilize three ground rules. At the beginning of the interview all children heard the rules; half also practiced them. Children then responded to open-ended prompts about a repeated laboratory event and were assessed for their application of the rules. Logistic regressions revealed that practice only benefitted the use of the “don't know” rule. Although the children accurately answered “don't understand” and “correct me” practice questions, practice appeared to give no greater benefit than just hearing the rules. Results suggest that the current format of ground rule practice in interview guidelines is appropriate for the “don't know” rule, but the other rules may require more extensive practice with this age group. Copyright © 2015 John Wiley & Sons, Ltd.     

The Effect of Different Types of Leading Questions on Adult Eyewitnesses with Mild Intellectual Disabilities

Adults with an intellectual disability (ID) are often considered poor witnesses; however, this may depend on the type of questions asked during investigative interviews. We examined the impact of four different types of misleading questions commonly used in interviews. These questions varied in their specificity, presumptive knowledge and structure (open or closed). Forty‐one adults with a mild ID watched a short film; they were then interviewed about what had happened. Half of the questions contained misleading information. In a later recognition test, participants showed a misinformation effect: they correctly recognised more items about which they had received control information than the items about which they had received misleading information. Closer inspection of the data revealed that both closed and open presumptive questions generated the largest misinformation effects. These findings highlight the vulnerability of adults with an ID to misleading questions, specifically those that presume certain information to be true. Copyright © 2013 John Wiley & Sons, Ltd.     

Manipulating Games by Sharing Information

We address the issue of manipulating games through communication. In the specific setting we consider (a variation of Boolean games), we assume there is some set of environment variables, the values of which are not directly accessible to players; the players have their own beliefs about these variables, and make decisions about what actions to perform based on these beliefs. The communication we consider takes the form of (truthful) announcements about the values of some environment variables; the effect of an announcement is the modification of the beliefs of the players who hear the announcement so that they accurately reflect the values of the announced variables. By choosing announcements appropriately, it is possible to perturb the game away from certain outcomes and towards others. We specifically focus on the issue of stabilisation: making announcements that transform a game from having no stable states to one that has stable configurations.     

Explain this: explaining childhood events inflates confidence for those events

To examine whether explaining hypothetical childhood events makes people more confident that the events really happened, we used a method similar to the imagination inflation procedure devised by Garry, Manning, Loftus, and Sherman (1996). First, participants rated how confident they were that a list of events occurred in their childhood. Two weeks later, participants explained how four of the eight target events could have happened to them before the age of 10. Finally, participants made confidence ratings about the list of childhood events for a second time. Participants were more confident that the explained hypothetical childhood events really did happen compared to events they did not explain. We discuss both theoretical and practical implications of these results. Copyright © 2004 John Wiley & Sons, Ltd.