Regional cerebral blood flow patterns during verbal and nonverbal auditory activation

Current views of the relationship between audition and cerebral function suggest that increases in regional cerebral blood flow (rCBF) would occur in the superior, mid, and posterior portions of the temporal lobes, and that these changes would be more lateralized to the left hemisphere for a verbal than a nonverbal auditory task. We measured rCBF using the xenon inhalation technique in a group of healthy subjects during three conditions: (1) resting baseline, (2) auditory verbal activation (listening for word meaning), and (3) auditory nonverbal activation (listening for reduction of intensity in a series of noise bursts). Both verbal and nonverbal conditions produced highly significant increases in rCBF over the left posterior Sylvian region with a trend for verbal activation to evoke a wider area of flow increase than the nonverbal task.     

The Impact of Alcohol on Negotiator Behavior: Experimental Evidence1

Business‐related drinking is an important organizational and managerial activity with particular relevance to the negotiation process. This paper investigates the influence of a moderate amount of alcohol on negotiator behavior and negotiated outcomes. We conducted 2 negotiation studies involving inebriated and sober participants, and found that inebriated negotiators used more aggressive tactics, made more mistakes, and reached less integrative agreements than did sober negotiators. Across both studies, we found that inebriated negotiators were unaware that alcohol had affected their negotiations.     

A Trajectory Approach to Causality

In this paper we propose a new approach to address the ramification problem in common-sense reasoning about action and change. We contrast the methods of McCain and Turner, Thielscher and Sandewall and, based on some of the limitations they encounter, we introduce a trajectory-based approach which keeps a history of the states through which a system evolves to characterise its dynamical state. We furnish an underlying state-transition semantics and a logic that admits an expressive, dynamical account of some typical scenarios which encounter modelling difficulties in the other approaches mentioned.     

Independence of long-term contextual memory and short-term perceptual hypotheses: Evidence from contextual cueing of interrupted search

Observers are able to resume an interrupted search trial faster relative to responding to a new, unseen display. This finding of rapid resumption is attributed to short-term perceptual hypotheses generated on the current look and confirmed upon subsequent looks at the same display. It has been suggested that the contents of perceptual hypotheses are similar to those of other forms of memory acquired long-term through repeated exposure to the same search displays over the course of several trials, that is, the memory supporting “contextual cueing.” In three experiments, we investigated the relationship between short-term perceptual hypotheses and long-term contextual memory. The results indicated that long-term, contextual memory of repeated displays neither affected the generation nor the confirmation of short-term perceptual hypotheses for these displays. Furthermore, the analysis of eye movements suggests that long-term memory provides an initial benefit in guiding attention to the target, whereas in subsequent looks guidance is entirely based on short-term perceptual hypotheses. Overall, the results reveal a picture of both long- and short-term memory contributing to reliable performance gains in interrupted search, while exerting their effects in an independent manner.     

Bug distribution and statistical pattern classification

A model (called the rule space model) which permits measuring cognitive skill acquisition, diagnosing cognitive errors, detecting the weaknesses and strengths of knowledge possessed by individuals was introduced earlier. This study further discusses the theoretical foundation of the model by introducing bug distribution and hypothesis testing (Bayes' decision rules for minimum errors) for classifying subjects into their most plausible latent state of knowledge. The model is illustrated with the domain of fraction arithmetic and compared with the results obtained from a conventional artificial intelligence approach.The authors would like to acknowledge Mr. Robert Baillie for developing several computer programs used for this research.This research was sponsored by the Personnel and Training Research Program, Psychological Sciences Division, Office of Naval Research.Some of the analyses presented in this report were performed on the PLATO® system. The PLATO® system is a development of the University of Illinois and PLATO® is a service mark of the Control Data Corporation.     

Modes d'expression en sociologie et en ethnologie

Sans résumé