The effects of varied retrieval cues on reminiscence in eyewitness memory

Eyewitnesses sometimes recall things at later interviews that they did not recall at previous interviews (reminiscence). When these cases are argued in the courtroom, attorneys may claim (and judges may warn jurors) that eyewitnesses who provide reminiscences are necessarily inaccurate witnesses. Consequently, their testimony may be prematurely discredited or dismissed. We examined here the role of varying the retrieval cues across interviews to account for reminiscence. Participants watched a videotaped mock crime and were tested for recall on two occasions using the same or different cues. Results supported the hypothesis that varying retrieval cues increases the amount of reminiscence. Furthermore, nearly all participants exhibited some reminiscence. Finally, reminiscence was not significantly correlated with overall accuracy of testimony. These findings suggest that many of the assumptions underlying legal tactics and judges' instructions regarding reminiscent inconsistencies are erroneous. Copyright © 2006 John Wiley & Sons, Ltd.     

Hippocampus function predicts severity of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is often accompanied by memory problems and abnormal brain structure, particularly within the hippocampus. We implemented a cross-species, hippocampal-dependent task--the virtual Morris Water task--to assess hippocampal function in people with PTSD and age-matched controls during functional magnetic resonance imaging (fMRI). Performance on the task was equivalent between the groups. However, when correlating fMRI-derived hippocampal activity during this task with PTSD severity, we observe a -0.84 correlation, indicating that those with reduced hippocampal activity show more severe PTSD symptoms. This correlation is not explained by differences in task performance, IQ, duration since trauma, nor time with PTSD. Hence, PTSD severity is predicted by functionally assessing the hippocampus using the virtual Morris water task, suggesting that this task may be used to identify those at risk for developing PTSD following a trauma.     

Effects of reinforcement magnitude and ratio values on behaviour maintained by a cyclic ratio schedule of reinforcement

In Experiments 1 and 2, lever pressing by rats was reinforced on a cyclic ratio schedule of food reinforcement, comprising a repeated sequence of fixed-ratio component schedules. Reinforcement magnitude was varied, on occasional sessions in Experiment 1 and across blocks of sessions in Experiment 2, from one to two or three 45-mg food pellets. In the one-pellet condition, post-reinforcement pauses increased with component schedule value. At higher magnitudes, post-reinforcement pauses increased, and overall response rates declined. Response rate on component schedules was a decreasing linear function of the obtained rate of reinforcement in all conditions. Plotted against component schedule value, response rate increased exponentially to an asymptote that decreased when reinforcement magnitude increased. These findings are consistent with regulatory accounts of food reinforced behaviour. In Experiment 3, rats were trained under a cyclic ratio schedule comprising fixed-ratio components including higher values, and some inverted U-shaped response functions were obtained. Those rats that did not showthis relationship were trained on cyclic ratios with even higher values, and all showed inverted U-shaped response functions. This suggests that behaviour on cyclic ratio schedules can reflect activating of reinforcement as well as the satiating effects seen in Experiments 1 and 2.     

The Ethics of Producing In Vitro Meat

The prospect of consumable meat produced in a laboratory setting without the need to raise and slaughter animals is both realistic and exciting. Not only could such in vitro meat become popular due to potential cost savings, but it also avoids many of the ethical and environmental problems with traditional meat productions. However, as with any new technology, in vitro meat is likely to face some detractors. We examine in detail three potential objections: 1) in vitro meat is disrespectful, either to nature or to animals; 2) it will reduce the number of happy animals in the world; and 3) it will open the door to cannibalism. While each objection has some attraction, we ultimately find that all can be overcome. The upshot is that in vitro meat production is generally permissible and, especially for ethical vegetarians, worth promoting.     

What 4′33″ Is

What is John Cage's 4′33″? This paper disambiguates this question into three sub-questions concerning, respectively, the work's ontological nature, the art form to which it belongs, and the genre it is in. We shall see that the work's performances consist of silence (rather than containing environmental sounds), that it is a work of performance art (rather than music), and that it belongs to the genre of conceptual art. Seeing the work in these ways helps us to understand it better, and promises to assuage somewhat the puzzlement and irritation of those who are at first resistant to its charms.     

The property of rationality: a guide to what rationality requires?

Can we employ the property of rationality in establishing what rationality requires? According to a central and formal thesis of John Broome’s work on rational requirements, the answer is ‘no’—at least if we expect a precise answer. In particular, Broome argues that (i) the property of full rationality (i.e. whether or not you are fully rational) is independent of whether we formulate conditional requirements of rationality as having a wide or a narrow logical scope. That is, (ii) by replacing a wide-scope requirement with a corresponding narrow-scope requirement (or vice versa), we do not alter the situations in which a person is fully rational. As a consequence, (iii) the property of full rationality is unable to guide us in determining whether a rational requirement has a wide or a narrow logical scope. We cannot resolve the wide/narrow scope debate by appealing to a theory of fully rational attitudes. This paper argues that (i), (ii) and (iii) are incorrect. Replacing a wide- with a corresponding narrow-scope requirement (or vice versa) can alter the set of circumstances in which a person is fully rational. The property of full rationality is therefore not independent of whether we formulate conditional requirements of rationality as having a wide or a narrow logical scope. As a consequence, the property of full rationality can guide us in determining what rationality requires—even in cases where we expect a precise answer.     

Rumination in Children with Social Anxiety Disorder: Effects of Cognitive Distraction and Relation to Social Stress Processing

According to cognitive models of social anxiety disorder (SAD), both anticipatory processing and post-event processing are core mechanisms in disorder maintenance leading to dysfunctional coping with social situations through negative self-evaluation and increased anxiety. To date, little is known about these processes during late childhood, a critical period for disorder development. Further, it remains unclear if dysfunctional rumination in children can be altered through psychotherapeutic interventions such as cognitive distraction. In the current study, children aged 9 to 13 years with SAD and age- and gender-matched healthy controls (HCs, each: n?=?30) participated in an experimental laboratory social stress task while anticipatory processing, post-event processing, subjective anxiety, self-evaluations, and autonomic arousal (skin conductance level) were assessed. Further, the impact of a brief cognitive distraction intervention on post-event processing was assessed. Children with SAD reported more negative anticipatory and post-event processing compared to HC children. Further, negative anticipatory processing was associated with higher subjective anxiety and reduced subjective performance ratings during the social stress task. In the aftermath of the stressor, distraction led to reduced subjective anxiety in the group with SAD and lower autonomic arousal in all children but did not alter post-event processing. The current study suggests that both anticipatory and post-event processing already play a key role in the maintenance of SAD in childhood. While distraction may be beneficial in reducing prolonged subjective anxiety and autonomic arousal after social situations, more research on interventions targeting ruminative processes is needed.