Role of the area postrema in three putative measures of motion sickness in the rat

After thermal cauterization of the area postrema in rats the absence of conditioned taste aversion to sucrose paired with lithium chloride (0.15 M, 3.3 ml/kg) was used as a pharmacologic/behavioral index of area postrema damage. In a subsequent experiment the effects of area postrema lesions on three measures proposed as species-relevant measures of motion sickness were studied, using off-vertical rotation at 150 degrees/s for either 30 or 90 min. Lesions of area postrema did not alter postrotational suppression of drinking or amount of defecation during motion. The initial acquisition of conditioned taste aversion to a novel cider vinegar solution paired with motion was not affected by lesioning of the area postrema, but these taste aversions extinguished more slowly in lesioned rats than in sham-operates or intact controls. Results are discussed in terms of proposed humoral factors which may induce motion sickness and in light of recent data on the role of the area postrema in similar measures in species possessing the complete emetic reflex.     

Developmental psychology in the real world: A paradigm of parent education

Twenty years ago, William Kessen, Greta Fein and I developed and tested a model of parent education, a model which involved variation in curricular content, didactic approaches, and child outcomes–experimentally contrasted. Our experience yielded some valuable lessons about the extent to which researchers can influence parents' behaviour, and parents their children's development. In the present article I suggest that these lessons might be useful for researchers now as they were for us then. I present some observations about the research that developmental psychologists have done in the intervening two decades and suggest that we could learn much by using such a model of parent education to answer questions about the effets of parents' behaviour on children's development. Carefully done, parent education studies can yield valuable information about many of the questions raised in recent correlational research. Parent training research can suggest hypotheses that can be tested with data collected non-interventively and analysed in causal model analyses–and vice versa. What is more, because one reason for studying parent effects is so that we can offer guidance to parents about rearing their children, this design has a particular advantage; it is both the medium and the message.     

Cross-sex comparisons: A word of caution

A cross-sex difference on one variable is often hypothesized to be related to a gender difference on a second variable. However, caution should be exercised in making such comparative hypotheses. We gathered the expected and actual examination grades for 168 female and 163 male college students. As in prior research, males had higher expectancies than females (p<.05). But analysis of the intrasex regression equations indicated that the relationship of expectancies to performance was different for women than it was for men. Thus, a cross-sex difference in expectancies did not correspond to a parallel difference in grades. This finding highlights the potential hazards of making certain cross-sex comparisons, and we argue for more caution in their application.     

Understanding Seat-Belt Intentions and Behavior: A Decision-Making Approach1

In an experimental study designed to investigate a decision-making model of seat-belt use, 227 employees of an agrochemical company participated in a health information program in which they watched either a videotape on seat belts or a control videotape and completed questionnaires immediately afterward and at 3 months and 1 year after exposure. In terms of total effects, the seat-belt videotape influenced beliefs, fear, and intentions assessed immediately after exposure, but had no effect on self-reported frequency of belt use at 3 months or 1 year. A full path analysis indicated some support for the decision-making model. In particular, probability difference (the perceived reduction in risk of death or serious injury due to wearing a belt) had a large influence on intentions to wear a belt and partly mediated the effect of the videotape on intentions. Reported frequency of belt use at 3 months was influenced both by post-test intentions and by initial frequency of belt use. Similarly, belt use at 1 year was affected by belt use at 3 months and by initial belt use. The findings are discussed in terms of the role of subjective probabilities and habitual factors in seat-belt use.     

The Effectiveness of Encounter Groups: Implications of Research for Counselling Practice

In the past decade, encounter groups have become a widely recognised technique of intervention for counsellors. Empirical research on encounter groups is confusing. Trends in research are obscured by a diversity of definitions, methodologies and subjects. This review considers the most significant research on the effectiveness of encounter groups, focusing on positive and negative effects, leader behaviour, group characteristics, participant characteristics, and the maintenance of change. Conclusions are drawn relating the research to practice, with some suggested guidelines for use of encounter groups in counselling interventions.     

A preliminary study of Hare's “Research Scale for the Assessment of Psychopathy” in mentally-abnormal offenders

The abbreviated (15-item) version of Hare's Research Scale for the Assessment of Psychopathy (RSAP) was investigated in a sample of male admissions to Broadmoor Special Hospital (N = 50), along with five MMPI measures relevant to psychopathy (Impulsivity, Sociability, Psychopathic Deviate, Anxiety and Sociopathy). Patients were assigned to one of four clinical diagnostic groups: Personality Disorder, Mixed (personality disorder with schizophrenia), Schizophrenia and Affective Disorder. Results indicated that while both psychopathic groups (Mixed and Personality Disorder) showed high scores on almost all RSAP items, the Affective Disorder group showed low scores on almost all items. Results of a discriminant function analysis indicated that Hare's RSAP was superior to the MMPI measures at discriminating between psychopaths and non-psychopaths. Use of the discriminant function to re-allocate patients to criterion groups showed a high hit rate (94%) for psychopathic patients but a hit rate of only 61% for non-psychopathic patients. Half of the schizophrenic patients were mis-allocated to the psychopathic group. The results support the idea of an affective deficit common to psychopaths and schizophrenics, but suggest that psychopaths additionally show a deficit which may be characterized by a lack of goal-directed behaviour.     

Anxiety and the spelling and use in sentences of threat/neutral homophones

The disambiguation of threat/neutral homophones was investigated in high- and low-trait anxiety subjects who had been exposed to either a positive or a negative mood manipulation procedure. Subjects were required first to spell each auditorily presented word and second, to generate and speak a sentence using the word. Difference indices were calculated for the spelling and the sentence usage data, i.e. the number of threat minus neutral interpretations. Examination of these indices revealed that subjects exposed to the negative mood manipulation procedure produced relatively more threat than neutral interpretations (for both spelling and sentence usage) than did subjects exposed to the positive mood manipulation procedure. Multiple regression analyses revealed that both the trait anxiety and mood manipulation variables contributed significantly to the prediction of the difference index on the spelling task. In the analysis of the use of homophones in sentences, only the mood manipulation variable contributed significantly to the prediction of the difference index on the sentence usage task.     

Regendering the U.S. Abortion Debate

This paper originated in a conference presentation with my colleague Michael Tooley, at which we were both asked to re-evaluate articles about abortion that each of us had written over twenty years earlier. While Tooley and I both contended that abortion should be legally unrestricted, there were striking differences in the style and content of our respective arguments. Contemplating these differences has reinforced my own belief in the importance of emphasizing the centrality of gender when discussing abortion. Since gender as we know it is a system of dominance as well as difference (MacKinnon 1987), I take this to mean that contemporary discussions of abortion must address the relationship between abortion access and the social status of women. My early article addressed this relationship to some extent, but the present paper will raise a number of additional gender issues that the early article did not mention.