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.     

Interactions between area and numerosity

Summary The concept of filled area, i.e. the impressionistic ensemble of parts of a stimulus field occupied by dots, is used to account for various kinds of numerosity illusions due to perceptual interaction between a number of dots and their spatial arrangement. A measure of filled area is derived from a model for the perceptual clustering of dots on the basis of relative proximity. It is shown that the quantified concept of filled area successfully predicts illusion data from earlier studies. Subsequently, a two-alternatives forced-choice numerosity experiment is reported, the data of which gave further evidence of the predictive power of the filled-area hypothesis. Our approach is discussed with respect to spatial features of dot stimuli that might be in rivalry with the filled-area factor in numerosity-estimation tasks.     

Effects of facial attractiveness and gender on causal attributions of managerial performance

The present study examined the effect of facial attractiveness and gender on raters' evaluations of and explanations for managerial performance. Results showed attractiveness to be a potential liability for both males and females. Good performance of attractive females was more likely than that of others to be attributed to luck or bias, while that of attractive males was viewed as occurring with little effort. In addition, the poor performance of attractive individuals was blamed on lack of effort (females) or lack of ability (males). Implications of these findings are discussed.An earlier version of this paper was published in the 1986 Proceedings of the Southern Management Association.     

Marriage Guidance Training and the Trainee's Own Marriage: A Prospective Study

Twenty trainees and 18 partners took part in a study of the effects of a marriage guidance training programme on their own marriage. Changes were assessed in two ways: retrospectively ('perceived' changes as assessed following training) and prospectively (changes calculated by comparing scores obtained before training and those obtained after training). For most dimensions there was little correspondence between 'perceived' change and 'calculated' change. This has important methodological implications, which are discussed. The 'calculated' change indicated poorer marital adjustment following training. The trainees' scores suggested that they had become less 'abasing' and less 'nurturant' towards their partners; also that they had more disagreements about 'philosophy of life' and 'dealing with in-laws'. Their comments suggested that a number of the trainees had become more analytical of their own marriages, and that training had heightened their awareness of their own needs and individuality.     

Emotional sequelae of abortion: implications for clinical practice

For women in therapy who have had abortions, an exploration of the context and aftermath of each abortion has been suggested. This inquiry should include: characteristics of the woman herself before and at the time of the abortion, the nature of the interpersonal and cultural milieu at the time, characteristics of the medical environment and procedure, and any events subsequent to the abortion that may evoke regrets about the earlier decision.
Whether or not such an inquiry results in the identification of unresolved issues surrounding the abortion, it is likely to enhance one's general understanding of the client. Exploring a woman's decision to have an abortion can bring into relief developmental and family issues, relationship conflicts, and her aspirations for education, work, and family. A woman's approach to establishing and asserting her priorities and values in making difficult personal decisions becomes clear as does her ability to tolerate and resolve the ambivalence inherent in making difficult decisions.
In psychotherapy, it is important to understand and address those aspects of experience that women have difficulty resolving. Hence, the emphasis on categories of experience that may have a negative impact on a woman's emotional well-being after abortion. Nevertheless, the clinician should remember that even women who report negative post-abortion sequelae overwhelmingly report that they feel that the decision was the right one for them. Having ambivalent feelings to resolve does not necessarily mean that one has made a wrong choice, only that one has made an emotionally significant choice with far-reaching personal implications, in a sociocultural environment that reinforces the ambivalence inherent in such decisions.     

An evaluation of the Garren-Edwards diet and behavior modification program

This study evaluated the efficacy of the Garren-Edwards Behavior Modification Program, which uses the Garren-Edwards Gastric Bubble as an adjunct to treatment. Group therapy sessions were conducted with 23 morbidly obese subjects for 6 months on a biweekly basis. Each therapy session used a five-stage problem-solving sequence designed to facilitate adaptive behavioral alternatives. In evaluating weight change, a multivariate analysis of variance was conducted along with two preplanned orthogonal comparisons. Patients lost significant amounts of weight between initial to 3-month (p<.0001) and 3- to 6-month intervals (p<0001). A similar treatment effect was noted in an additional sample of 24 morbidly obese subjects following 3 months of treatment (p<0005). The findings support the value of longer goal-oriented programs in promoting continued weight loss. Implications for treatment process and therapist interventions prompted by this new format are discussed.     

Reversal of genetic homeostasis in laboratory populations of Drosophila melanogaster under long-term selection for geotaxis and estimates of gene correlates: evolution of behavior-genetic systems

Among Drosophila melanogaster, divergently selected for geotaxis intermittently over 600 generations (28 years), about 80,000 animals have been analyzed behavior-genetically. Each major chromosome pair from two lines was isogenized on an unselected isogenic background. Measurement of their behavioral effects revealed the relative magnitudes II greater than III greater than X for the negatively geotactic (high) line and X greater than III greater than II for the positively geotactic (low) line. When reversing selection for the now phenotypically stable high and low lines and then repeatedly relaxing the reversals, a new genetic homeostasis in the low line was indicated by the return of the reversed-line average scores towards the low extreme; that is, the low line has attained a stable equilibrium for positive geotaxis, an uncharacteristic behavior and an effect not seen before 1979. This change suggests the recent evolution of a new coadaptation among genes. Although not as conclusive, a similar genetic interpretation is suggested for the high line.     

Two forms of minority-group test bias as psychometric artifacts with an animal model (Rattus norvegicus)

Controversy abounds over attributing group differences on tests to nature, nurture, or test bias. Limitations of correlational sampling from natural populations necessitate experimental methods to resolve underlying issues. In classical psychometrics test items are selected from a larger item pool through analysis of item responses in a sample of subjects. Rats of six inbred strains (n = 366) were tested in multiple mazes to provide a large item pool. Six populations were created, each with differing proportions of each strain. Items selected through independent item analyses within each population yielded six tests. An independent cross-validation sample (n = 146) provided scores on all six tests. This sample was also tested in another set of maze problems defined as the criterion to be predicted. Strain means and intrastrain predictive validities for the six tests varied with strain representation in the population used for item selection (p less than .001). Conventional item-selection procedures clearly produced two forms of minority test bias.     

Confidence in judgments based on incomplete information: An investigation using both hypothetical and real gambles

This study assessed how confidence in judgments is affected by the need to make inferences about missing information. Subjects indicated their likelihood of taking each of a series of gambles based on both probability and payoff information or only one of these sources of information. They also rated their confidence in each likelihood judgment. Subjects in the Explicit Inference condition were asked to explicitly estimate the values of missing information before making their responses while subjects in the Implicit Inference condition were not. The manner in which probability information was framed was also manipulated. Experiment 1 employed hypothetical gambles and Experiment 2 employed gambles with real money. Expressed likelihood of taking gambles was higher when probability was phrased in terms of '% chance of winning' rather than '% chance of losing', but this difference was somewhat less with real gambles than with hypothetical gambles. Confidence ratings in each experiment were actually higher on incomplete information trials than on complete information trials in the Explicit Inference condition. Results were related to the general issue of confidence in judgments.     

Individual differences in reverse Hindsight bias: I never thought something like chernobyl would happen. Did I?

Hindsight bias was studied in the context of the accident in the Chernobyl nuclear power plant, which took place on April 26th 1986. An individual difference factor which relates to the motivation to process information, need for cognition, was expected to moderate the occurrence of hindsight bias. Probability estimates of many casualties due to the use of nuclear power in The Netherlands were obtained from 212 individuals two months before the accident in Chernobyl. These estimates were compared with similar estimates made in hindsight by the same individuals five months after the accident. Loglinear Analyses reveal a systematic hindsight bias. However, the direction of the bias was contrary to expectations. In hindsight, individuals gave lower probabilities than they actually did two months before the Chernobyl accident. These results reveal a reverse hindsight bias. As hypothesized, need for cognition moderates hindsight bias: individuals low and medium in need for cognition express a systematic reverse hindsight bias, while individuals high in need for cognition do not. High need for cognition individuals also show higher literal consistency between the two measurements, which supports a memory explanation of the moderating effect of need for cognition.