Maps between some different kinds of contraction function: The finite case

In some recent papers, the authors and Peter Gärdenfors have defined and studied two different kinds of formal operation, conceived as possible representations of the intuitive process of contracting a theory to eliminate a proposition. These are partial meet contraction (including as limiting cases full meet contraction and maxichoice contraction) and safe contraction. It is known, via the representation theorem for the former, that every safe contraction operation over a theory is a partial meet contraction over that theory. The purpose of the present paper is to study the relationship more finely, by seeking an explicit map between the component orderings involved in each of the two kinds of contraction. It is shown that at least in the finite case a suitable map exists, with the consequence that the relational, transitively relational, and antisymmetrically relational partial meet contraction functions form identifiable subclasses of the safe contraction functions, over any theory finite modulo logical equivalence. In the process of constructing the map, as the composition of four simple transformations, mediating notions of bottom and top contraction are introduced. The study of the infinite case remains open.     

Evidence that fixation digits can contribute to visual field asymmetries in lateralized tachistoscopic tasks

Fixation point digits have been widely used in tachistoscopic laterality studies as a simple and convenient means of ensuring unihemispheric projection of stimulus materials to the hemispheres. Previous findings demonstrate that fixation digits do not influence asymmetries in recognition accuracy studies with adult Ss. Present results, comparing four conditions differing in their use of fixation digits, show that in the naming latency paradigm the requirement to remember and report fixation control digits significantly augments RVF superiority. Implications for other latency tasks are discussed.     

Psychopathology subtypes and symptom correlates among former prisoners of war

Psychopathology and symptom patterns were studied in 60 former prisoners-of-war (POWs) by administering standardized tests including the Minnesota Multiphasic Personality Inventory (MMPI), an adjustment problem checklist, and a structured clinical interview. Most POWs showed marked psychological impairment, but modal profile analysis identified two prototypic MMPI patterns, which differed in pervasiveness and type of psychopathology. Profile subtypes were defined by unique clusters of clinical symptoms and differed in confinement stress severity. The typology of symptoms argues against a homogeneous conceptualization of stress-induced disorders and suggests the need for definition of the severity and subtype of stress phenomena and individual difference factors in responding to trauma.     

Sandra Day O'Connor and the justification of abortion

The recent Supreme Court decision upholding Roe v. Wade and in particular, the dissent by Justice Sandra Day O'Connor, sheds new light on the issue of abortion. Let us consider any stage of a pregnancy when abortion is medically safe for the mother. If at that stage it is also medically viable to save the fetus, is an abortion performed at that stage of pregnancy morally justifiable? For example, if it is, or becomes, medically safe to perform abortions after first trimester of pregnancy and at the same time saving a fetus is, or becomes, medically viable or not unusual during some stage of the second trimester, can abortions during and after that stage of pregnancy be justified? With a number of qualifications I shall argue the thesis that as a general rule, but not an absolute rule, abortion in these instances is not usually justifiable. For if it is, then one will also have to grant the moral justification for a number of other highly questionable medical practices. This thesis is not to be identified with the stronger claim that abortions of viable fetuses can never be performed. There are surely exceptions such as when the life or health of the mother is in danger. But, I shall argue, the justification for making such exceptions is on different grounds than is sometimes claimed because one must weigh the health of the mother against the life of another human being.     

Mary and femininity: A psychological critique

This essay uses Freud to interpret the symbolism and theology of Mary in modern Catholicism. In her role as the mother of believers, Mary functions to place the Christian in the position of a child who receives illusory gratification from the mother. In her role as model for Christians to emulate, Mary functions to place the Christian in the position of receptivity and dependence which Freud associated with femininity. Reinterpreting Freud from a feminist perspective, I suggest that the kind of femininity Mary represents serves to perpetuate patriachal social structures and to inhibit full psychological maturity.     

Associative and serial-order information: Different modes of operation?

Two versions of a distributed-memory model, one for associative information and one for serial-order information, leave open the question of whether there are two different modes of operation or only one. An analysis of these two versions showed that differential predictions emerge when one considers the role of item information. To test these predictions, a standard item-recognition task (Sternberg, 1966) was embedded in a paired-associate probe-recognition task, a serial-order probe-recognition task, or both. The item-recognition serial-position curves were quite different in the paired-associate and the serial-order conditions, and followed the paired-associate condition when the two were combined. In general, the results were consistent with the predictions of the distributed-memory models, and supported the idea of different modes of operation rather than a single common mode of operation.     

A multivariable analysis of spatial abilities by sex

This article presents a series of studies investigating the influence of experimental factors and the personological variables of age and sex upon spatial abilities. It was hypothesized that the overall equivocal findings typical of spatial research may be partially due to the use of different factors across studies. The experimental variables of spatial factor, task demands, spatial information type, information-processing mode, and response mode were systematically manipulated across the eight studies. In each individual analysis of data collected in a specific study, no significant main effect sex differences were detected. However, when a meta-analytic review of the studies was conducted, both spatial information dimensionality and information dimensionality × spatial factor assessed proved to be influential on male and female spatial performances. Female performance was superior when the dimensionality of stimulus and response variables was invariant. Males had the advantage when dimensionality crossing was necessitated. The discrepancy between the sexes was particularly dramatic when the spatial orientation factor was tapped.     

A general structural equation model with dichotomous,ordered categorical,and continuous latent variable indicators

A structural equation model is proposed with a generalized measurement part, allowing for dichotomous and ordered categorical variables (indicators) in addition to continuous ones. A computationally feasible three-stage estimator is proposed for any combination of observed variable types. This approach provides large-sample chi-square tests of fit and standard errors of estimates for situations not previously covered. Two multiple-indicator modeling examples are given. One is a simultaneous analysis of two groups with a structural equation model underlying skewed Likert variables. The second is a longitudinal model with a structural model for multivariate probit regressions.This research was supported by Grant No. 81-IJ-CX-0015 from the National Institute of Justice, by Grant No. DA 01070 from the U.S. Public Health Service, and by Grant No. SES-8312583 from the National Science Foundation. I thank Julie Honig for drawing the figures. Requests for reprints should be sent to Bengt Muthén, Graduate School of Education, University of California, Los Angeles, California 90024.     

Depressed mood and environmental mastery as potential pathways linking family relationship quality and disease self-management for African Americans with hypertension

African Americans are at significantly greater risk of hypertension and worse cardiovascular outcomes than other racialized groups, yet hypertension intervention effects remain limited. Thus, it is necessary to understand the potential mechanisms whereby interventions may be more effectively targeted to improve health. Supported by prior research evidence and guided by the Biobehavioral Family Model, this study examined associations between family relationship quality, psychological wellbeing, and self-management behaviors for African Americans with hypertension. Data were pooled from three Midlife Development in the U.S. projects, resulting in a sample of 317 African Americans (63.4% female, M_age = 53.32) with self-reported high blood pressure in the past 12 months. We tested four cross-sectional multiple mediator models, with depressed mood and environmental mastery mediating associations between family strain and exercise, smoking, problematic alcohol use, and stress-eating. Environmental mastery mediated the association between greater family strain and decreased odds of achieving recommended exercise levels; greater odds of reporting problematic alcohol use; and greater stress-eating. Though family strain was associated with depressed mood in each model, this variable did not serve as an indirect pathway to self-management behaviors. Family strain, and the potential pathway identified via environmental mastery, may be a meaningful predictor of disease self-management for African Americans with hypertension. Longitudinal studies are needed to examine directionality and to support intervention trials for improving self-management and hypertension outcomes.