Death and dying in medicine: What questions are still worth asking?

Theoretical Medicine and Bioethics -     

An analysis of some sensitizing agents in the pathogenesis of stress-induced gastric erosive disease

Prior surgical implantation of a venous catheter sensitized rats to coldimmobilization stress. Three of six catheterized females succumbed during the stress. The remaining rats fell into two groups in terms of their core temperature at the end of the stress period: Male uncatheterized rats had higher temperatures than rats in the other three groups. No relation was found between catheter patency and magnitude of hypothermia. Degree of gastric disease paralleled the core temperature findings in that the male uncatheterized rats had significantly fewer gastric erosions than the rats in the other three groups. Additionally, a robust effect of gender was found with uncatheterized females showing more hypothermia and more gastric disease than uncatheterized males. A subsequent experiment was conducted to evaluate whether anesthesia or wearing the protective spring was responsible in part for the sensitization seen. Here, the gender difference was less although females consistently averaged lower core temperatures after stress than did males. Despite similar core temperatures after stress, females that were prepared with the protective spring apparatus developed more gastric disease than female controls or similarly treated males. Thus, the additional sensitization exhibited by females in the first experiment may relate to the fact that both catheterization and the taping procedure were sensitizers while only catheterization was a sensitizer for males.     

Midi-level measurement of social anxiety in psychiatric and non-psychiatric samples

This paper reports the development and assessment of midi-level behavioral measures of social anxiety in the context of two experiments, one studying an analog student sample, the other a psychiatric sample. Judgments on nine categories of clinically practical midi-level behaviors (e.g. Facial Expression, Orienting, Sense of Timing), based on a review of the literature on human ethology and on pilot research, were compared to global judgments of social anxiety and social skill and to physiological arousal. Intraclass correlations exceeded 0.80 for judgments of the global and midi-level behavioral ratings on both samples. Results of correlational analyses indicated that while there were several significant predictors of global skill and anxiety among the midis, the magnitude of the relationship between midis and globals was stronger for the patient than the student sample. Further analyses based on S's heart rate (HR) reactivity suggested that while global ratings did not significantly predict H R in a high social anxiety situation, one midi-level behavioral rating (self-manipulations) did. The clinical utility of the newly developed measures is discussed with particular attention to their practicality for behavior therapy.     

How normal and retarded individuals monitor and regulate speed and accuracy of responding in serial choice tasks

These experiments investigate whether or not differences in the way that retarded and nonretarded individuals monitor and regulate speed and accuracy of responding contribute to the slower and more variable performance of retarded subjects on choice reaction time (RT) tasks. Rabbitt (1979, 1981) suggested that efficient choice RT performance is mediated by subjects tracking increasingly faster RT bands on successive trials until, by making and recognizing errors, they discover those very fast RT levels that should be avoided and those safe bands, just above typical error levels, that should be tracked. Experiments 1A and 1B established that most retarded subjects detect their errors as efficiently as nonretarded controls, a finding that excludes the possibility that retarded subjects do not monitor accuracy efficiently but achieve comparable levels of accuracy by consistently responding within very slow RT bands that minimize likelihood of errors. Experiment 2 showed that while a qualitatively similar trial-by-trial tracking mechanism mediates the performance of both groups, retarded subjects are less efficient at constraining RTs within very fast, but safe, bands. Increasing error probabilities at longer RTs suggest that momentary fluctuations in stimulus discriminability and/or attention are factors affecting RT variability in retarded subjects. The RT patterns for various sequences of correct responses initiated and terminated by errors suggest that the effective past experience (EPEX) guiding trial-by-trial RT adjustments of retarded subjects is short and inadequate, and it was argued that this can account for much of the remaining RT variability contributing to retarded-nonretarded differences. Not only does a short EPEX increase variability by giving rise to long error-free sequences of slower than average RT but also, when combined with occasional specified random fluctuations, it suggests why retarded subjects can achieve, but not sustain, RT levels maintained by nonretarded subjects.     

Stimulus selection in passive avoidance learning and retention: weanling, periadolescent, and young adult rats

Periadolescent rats exhibit a number of behavioral differences in comparison with younger or older animals. For instance, periadolescents tend to show enhanced acquisition of simple active avoidance tasks, but impaired acquisition of more complex appetitive and aversive discriminations. In this experiment, rats were trained on a simple passive avoidance task at one of three ages, as weanlings (25 days), periadolescents (35 days), or young adults (45 days). Training occurred in the presence of both a redundant discriminative stimulus and a specified, redundant contextual stimulus. The periadolescents did not differ from either younger or older rats in rate of learning the passive avoidance task. The retention performance of these animals was then tested following a change in either, neither, or both of the redundant cues. When a measure of performance that controls for baseline activity was used, it was observed that periadolescents were not disrupted by a change in the redundant discriminative stimulus, a cue change that clearly disrupted performance in 25- and 45-day-old animals, and tended to be more disrupted by the contextual change than younger or older rats. It is hypothesized that the alterations in performance exhibited by periadolescents may be related to an ontogenetic alteration in stimulus selection modulated by the catecholaminergic systems.     

Peer education: The untapped potential

The purpose of this paper is to provide a rationale for making broader educational use of peer learning principles as explicated in developmental theory and research. The paper argues that peer learning brings with it unique motivational and cognitive benefits for participating peers. Research has shown that peer learning can bolster children's self-esteem, awaken their interest in challenging tasks, enhance scholarly achievement, and foster prosocial behavior. In particular, it is an effective means of enabling children to grasp basic concepts that underlie school curricula.Two different forms of peer learning, “peer tutoring” and “peer collaboration,” are distinguished. Each has its potential use: peer tutoring for transmitting information and drilling special skills; peer collaboration for facilitating intellectual discovery and the acquisition of basic knowledge.Some general guidelines for the integration of peer tutoring and peer collaboration in the classroom are offered. It is recognized that specific curriculum plans implementing these guidelines must be formulated with a view to the overall cultural context of the school system. Such plans must be molded in context to suit the needs of each particular site. It is concluded, however, that the general principles of peer education set forth in this position paper would enhance all varieties of schooling. As explicated in this article, peer education complements rather than supplants adult teaching, freeing up teachers' time and attention and enabling them to focus more directly and effectively on individual children's learning needs.     

Revision of the self-monitoring scale

Snyder's (1974) Self-Monitoring Scale exhibits a stable factor structure that does not correspond to the five-component theoretical structure he presents. Sets of face-valid items that better approximate the theoretical structure are described. Correlations between these sets of items and measures of other constructs reveal that four of the five components are positively related to social anxiety. Effective social interaction is supposedly the high self-monitor's forte, and social anxiety appears to be incompatible with this. The correlational results therefore question the entire theory and indicate the need for a narrower definition of the construct. Adopting such a definition from Snyder's review article (1979), we present a 13-item Revised Self-Monitoring scale which measures only sensitivity to the expressive behavior of others and ability to modify self-presentation. A 20-item Concern for Appropriateness scale is also described. This scale measures 2 variables that are directly associated with social anxiety--cross-situational variability and attention to social comparison information. Both scales have acceptable internal consistency, and both yield 2 subscale scores as well as a total score. Prospective users of either scale are advised to treat the 3 scores separately.