Graph-theoretic representations for proximity matrices through strongly-anti-Robinson or circular strongly-anti-Robinson matrices

There are various optimization strategies for approximating, through the minimization of a least-squares loss function, a given symmetric proximity matrix by a sum of matrices each subject to some collection of order constraints on its entries. We extend these approaches to include components in the approximating sum that satisfy what are called the strongly-anti-Robinson (SAR) or circular strongly-anti-Robinson (CSAR) restrictions. A matrix that is SAR or CSAR is representable by a particular graph-theoretic structure, where each matrix entry is reproducible from certain minimum path lengths in the graph. One published proximity matrix is used extensively to illustrate the types of approximation that ensue when the SAR or CSAR constraints are imposed.The authors are indebted to Boris Mirkin who first noted in a personal communication to one of us (LH, April 22, 1996) that the optimization method for fitting anti-Robinson matrices in Hubert and Arabie (1994) should be extendable to the fitting of strongly anti-Robinson matrices as well.     

Gender stereotypes of parents with two-year-olds and beliefs about gender differences in behavior

A sample of British parents of two-year-olds was asked about gender-related adult roles, beliefs about gender differences in children's behavior, and whether they perceived their own child in terms of gender-specific behaviors. The majority of the children were perceived as conforming to gender stereotypes, and in particular, boys were seen this way by fathers. Parents cited as evidence behavior that corresponds closely to the content of adult sex role inventories. The parents were not positive about changes in the traditional gender-related work/child care division of labor.     

A rule-based expert system for music perception

We describe an expert system written in Pascal to simulate part of Lerdahl and Jackendoff’s (1983) theory of music perception. This program, a production system based on a Hearsay II architecture (Nii, 1986), illustrates a number of techniques, including program modularity, complex data structures, and simulated parallelism using operating system concepts.     

Ethnicity,culture, and social resources

Assessed social integration (existence or quantity of relationships) and social (specifically, emotional) support in Mexican Americans (MAs) and non-Hispanic whites (NHWs). Ethnic differences were seen as arising from (a) demographic differences between ethnic groups that account for ethnic differences; (b) demographic attributes that have different associations with social resources for each ethnic group; (c) ethnic differences independent of these explanations. Study participants were 538 U.S.-born MA, 706 Mexico-born MA, and 1,149 NHW randomly selected community residents. Immigrants were more often married, and MAs and immigrants reported fewer friends and less emotional support, regardless of demographic attributes. Ethnic differences in demographic attributes accounted for MAs' and immigrants' smaller kin networks. Ethnic differences in demographic correlates of working accounted for MAs' lower employment rates.     

DISCRIMINATION OF LATERALLY DISPLAYED HANDWRITING AND HANDWRITTEN WORDS*

Four highly discriminable words each written in four highly discriminable natural kinds of handwriting were paired and laterally displayed for 180 msec. Thirty-two normal females made same/different judgments for the words and for handwriting; there were 136 trials in each condition. Accuracy and manual reaction times of correct responses were recorded. The usual right-field (left cerebral hemisphere) superiority was observed for word comparisons, but no clear asymmetry emerged for handwriting comparisons. An interference of the words in the comparisons of handwriting was observed mainly in the right field, and interference of the handwriting in the judgments on words occurred equally in both fields.     

Teaching ethics on rounds: The ethicist as teacher,consultant, and decision-maker

This paper explores the relationship between teaching and consulting in clinical ethics teaching and the role of the ethics teacher in clinical decision-making. Three roles of the clinical ethics teacher are discussed and illustrated with examples from the authors' experience. Two models of the ethics consultant are contrasted, with an argument presented for the ethics consultant as decision facilitator. A concluding section points to some of the challenges of clinical ethics teaching.     

The relationship between attributions and depression varies across attributional dimensions and across samples

Two hypotheses implicit in the use of composite measures of attributions in tests of learned helplessness theory (but not implicit in the theory itself) were tested: the hypotheses that relationships between depression and the three types of attributions are equal in magnitude and are linear. To test these hypotheses, data from three published studies of the reformulated learned helplessness theory (Abramson, Seligman, & Teasdale, 1978) were reanalyzed. The hypothesis that internal, stable, and global attributions are equally related to depression was tested and rejected. Increases in internal attributions were related to depression in one sample; increases in global attributions for negative events were related to depression in two samples; stability attributions for negative events were unrelated to depression. The relationship between attributions and depression was nonlinear in one of the three populations studied. Finally, a third hypothesis was tested: the hypothesis that the relationship between attributions and depression is equal across samples. The hypothesis was rejected: attributions for negative events were more highly related to depression in a psychiatric sample than in normal populations. Implications of these findings for learned helplessness theory and for the use of composite measures of attributional style are discussed.     

Frontal deficits differentiate progressive supranuclear palsy from Parkinson's disease

The clinical differentiation of progressive supranuclear palsy from Parkinson's disease can be challenging, due to overlapping clinical features and a lack of diagnostic markers. Abnormalities in cognitive function form part of the clinical spectrums of these diseases and distinctive cognitive profiles may be helpful in differentiating these diseases in the diagnostic period. A comprehensive neuropsychological test battery was administered to 12 patients with clinically diagnosed progressive supranuclear palsy and 12 patients with Parkinson's disease matched for age and disease duration. Effect size (Cohen's d) was calculated for cognitive tests that were significantly different between groups. Patients with progressive supranuclear palsy performed significantly worse than those with Parkinson's disease on measures of processing speed, verbal fluency, planning, verbal abstract reasoning, verbal memory, and made more perseverative responses on a set shifting task. Measures of executive function, manual dexterity and processing speed were most diagnostically useful (Cohen's d > 2.0) in differentiating between progressive supranuclear palsy and Parkinson's disease. These findings suggest that more severe and prominent ‘frontal’ cognitive deficits in patients with progressive parkinsonism would be helpful in predicting progressive supranuclear palsy rather than Parkinson's disease and these findings may contribute to the development of diagnostic criteria.