Pavlovian inhibitory conditioning and tolerance to pentobarbital-induced hypothermia in rats

In this experiment we investigated inhibitory Pavlovian conditioning in the development of tolerance to pentobarbital-induced hypothermia. During an initial phase, one group of rats (discrimination group) received training in which, on alternate days, one conditional stimulus (CS+) was associated with administration of 30 mg/kg pentobarbital, and a different conditional stimulus (CS-) was associated with administration of physiological saline. During the phase, control groups received either exposure to both CSs but not the drug or to the drug but no CSs or to neither the CSs nor the drug. Subsequently, half the rats in each group received injections of pentobarbital in the presence of one of the CSs and the remaining half in the presence of the other CS. Rats from the discrimination group injected with pentobarbital in the presence of CS+ displayed the most tolerance (i.e., smallest drug effect), whereas rats from the discrimination group injected with pentobarbital in the presence of CS- displayed the least tolerance (i.e., greatest drug effect). The attenuation of tolerance seen in rats of the discrimination group injected in the presence of CS- provides evidence of inhibitory Pavlovian conditioning. Additional evidence of inhibitory conditioning was provided by the fact that CS2 enhanced the hypothermic effects of pentobarbital in the discrimination group, whereas CS1 attenuated these effects. Implications of the results for the nature of inhibitory conditioning are discussed.     

Stressful life events and use of physician services among the elderly: the moderating role of pet ownership

The physician utilization behavior of 938 Medicare enrollees in a health maintenance organization was prospectively followed for 1 year. With demographic characteristics and health status at baseline controlled for, respondents who owned pets reported fewer doctor contacts over the 1-year period than respondents who did not own pets. Furthermore, pets seemed to help their owners in times of stress. The accumulation of prebaseline stressful life events was associated with increased doctor contacts during the study year for respondents without pets. This relationship did not emerge for pet owners. Owners of dogs, in particular, were buffered from the impact of stressful life events on physician utilization. Additional analyses showed that dog owners in comparison to owners of other pets spent more time with their pets and felt that their pets were more important to them. Thus, dogs more than other pets provided their owners with companionship and an object of attachment.     

The effects of methylphenidate on levels of processing and laterality in children with attention deficit disorder

Effects of stimulant medication (methylphenidate) on levels (feature, name, semantic) of word processing by the left and right hemisphere were assessed in 31 attention- deficit- disordered children. In a double-blind procedure, same- different decisions were made to tachistoscopically presented word pairs under medication and placebo. Analysis of manual response times failed to show any negative effects of medication. Feature decisions were faster than name decisions, which were faster than semantic decisions. Methylphenidate induced a right visual field advantage (left hemisphere) for the name decision, which was interpreted as a normalization effect. The results suggest that (1) methylphenidate may selectively improve the phonological level of word processing and (2) methylphenidate's favorable therapeutic effect is produced through inhibition of excessive right hemisphere activity in response to task demands that engage the left hemisphere.This research is based in part upon a doctoral thesis completed by the first author in the Department of Education, University of Toronto. The authors thank Dr. William Logan and Dr. Wendy Roberts of the Hospital for Sick Children for permitting testing of patients in the Child Development Clinic. This research was supported in part by a doctoral fellowship from the Social Sciences and Humanities Research Council to the first author.     

Attributional style and self-control behavior in depressed and nondepressed children and their parents

Do the reformulated model of learned helplessness and the self-control model apply to clinically depressed children? Are the related cognitive patterns specific to depression? Are the cognitive deficits associated with depression learned from one's parents? To address these questions this investigation examined three groups of children (ages 8–12) and their parents: nonclinic (n =25),nondepressed clinic (n=22),and depressed clinic (n=15).Children were diagnosed depressed on the basis of Kiddie-SADS interview data. Depressed clinic children self-reported more depression, had a more depressive attributional style, and had more self-control problems. There were more depressed mothers in the clinic than in the nonclinic sample. Depressed clinic children had more depressed mothers than did nondepressed clinic children. There were no differences among the three groups of parents in their cognitive patterns. No relationship was found between the attributional style and self-control behavior of children and their parents.     

Use of pocket computers for self-administration of cognitive tests in the field

A pocket computer is described that can be used by subjects to self-administer cognitive tests in field situations. Two cognitive tests, a vigilance and an encoding task, were developed for this computer and used to test cognitive performance during a 30-day military field exercise.     

Modes of understanding and mindfulness in clinical medicine

Beginning with a case vignette, this paper uses a semiotic approach to analyze several different kinds of understanding used in clinical medicine. By outlining semiotic structures, four distinct modes of understanding can be defined: (1) the representational mode, corresponding to scientific medicine; (2) the pragmatic mode, constituting the basic standpoint of medicine; (3) the hermeneutic mode, underlying the empathic, humanistic spirit of medicine; and (4) the ontologic mode, associated with both the ethical and ritual aspects of medicine. Clarifying the relationship between these modes avoids common confusions in clinical situations. Although experienced clinicians intuitively use these different modes, they do not necessarily reflect upon them. They are instead mindful of them, and this unique multi-modal consciousness, I suggest, provides a model for integrating theory and practice.This work was supported in part by the Robert Wood Johnson Clinical Scholars Program.     

Psychological effects of prenatal diagnosis: The example of fetal echocardiography

This article presents two studies investigating the psychological effects of fetal echocar-diography (FE). The first compared the effects of FE in high risk and obstetrically normal women. High-risk women were more anxious beforehand and had more negative attitudes. Following a normal scan their attitudes and anxiety were equivalent to the controls but a large variation in postscan psychological changes was found. This variation was examined in the second study with a larger sample. Selected background variables predicted prescan anxiety and anxiety reduction following a normal scan. Quality of communication and feedback also determined postscan anxiety level and rated satisfaction in the two-week follow-up questionnaire. Some suggestions for routine medical practice are included.     

Smoking Prevention and the Concept of Risk1

Sixth-grade children in 22 schools received either a social-influences smoking-prevention program or routine health education. The social-influences program was designed to teach youth about peer, parent, and media influences affecting smoking onset and to provide them with skills in resisting these influences. Comparison schools were given no program, but were permitted to continue their usual provision of health education. Program impact was evaluated as a function of pretreatment risk of future smoking. Risk was defined with respect to both (a) the prevalence of social models who smoked and (b) previous smoking experience. Two-and-a-half-year results show program impact to vary with both kinds of risk. Smoking-experience risk interacted such that, at first, there was greater impact on children with experience, but on later follow-up the pattern reversed, with the greater treatment effects seen for those initially with limited experience. Social-models risk showed a direct relationship, with greater risk being associated with greater program impact. Implications both for evaluation research and prevention programs are discussed.     

A cross-validation of sex differences in the expression of depression

A considerable amount of evidence has accumulated indicating a greater rate of depression among females compared to males. In addition, recent investigations have revealed distinct patterns of depressive responding as a function of sex. The present study provided a cross-validational test of findings reported by Funabiki and colleagues. Male and female college students indicated the likelihood that they would engage in 79 behavioral analytically derived behaviors or cognitions if depressed. Stepwise discriminant function analyses were performed to determine maximum separation of male and female responses. This procedure yielded a 55.6% overall variable cross-validation rate. Many of the findings were consistent with Radloff and Rae's theoretical view of sex differences in learned susceptibility to depression. The data also suggest several avenues for future research and support the utility of investigating theories of depression within the context of a continuity between normal mood states and depressive phenomena.Useful comments on an earlier draft of this article were provided by Mark Hammarlund and Lorence S. Miller. The order of authorship was determined by the flip of a coin.     

Health care and the prospective Pareto principle

Issues of social justice in access to health care are examined from the standpoint of the "prospective," or "ex ante," Pareto principle, an ethical principle which holds that one policy is to be preferred over another if it betters the prospects of some persons while the alternative betters no one's prospects. It is suggested that this principle may validate a form of utilitarianism in health policy decisions, with equity demanding that everyone have access to a decent minimum of care but not necessarily to all highly expensive treatments.