A maximum likelihood method for latent class regression involving a censored dependent variable

The standard tobit or censored regression model is typically utilized for regression analysis when the dependent variable is censored. This model is generalized by developing a conditional mixture, maximum likelihood method for latent class censored regression. The proposed method simultaneously estimates separate regression functions and subject membership in K latent classes or groups given a censored dependent variable for a cross-section of subjects. Maximum likelihood estimates are obtained using an EM algorithm. The proposed method is illustrated via a consumer psychology application.     

Parental functioning and children's adjustment in families of divorce: A prospective study

This paper prospectively examined relations between marital status, predivorce parenting practices, and children's adjustment, using data from the New York Longitudinal Study (NYLS). Prospective analyses of children's predivorce adjustment indicated that neither boys nor girls showed more problematic behavior prior to parental separation, and only boys had more difficulties after divorce. However, parents of to-be-divorced families reported more difficulties in childcare practices before divorce than did parents of always-married families. Parenting difficulties in to-be-divorced families were found consistently for boys but not for girls. Results suggest that the difficulties found among boys after divorce may be linked with parenting problems that begin before divorce.The authors are indebted to Alexander Thomas and Stella Chess, the original investigators of the project. We also would like to thank Jacqueline and Richard Lerner, and the John D. and Catherine MacArthur Foundation for their efforts in preserving this data base.     

The Sum and Substance of It: The Appreciation of Mass and Count Quantifiers in Parkinson′s Disease

We performed three experiments in order to determine whether patients with Parkinson′s disease (PD) have a sentence comprehension impairment. In the first experiment, we found that nondemented PD patients were impaired at matching a short sentence containing a mass or count quantifier (e.g., "Point to the jar with many") with one of four pictures. Patients erred by pointing to the incorrect mass or count type of substance, but pointed correctly to the large or small amount of a substance in the picture. In the second experiment, we asked the same PD patients to judge short sentences containing mass or count nouns modified by mass or count adjectives (e.g., *"The glass contains many milk"). PD patients were significantly impaired at detecting errors in the agreement between a noun and a quantifying adjective and errors in the appropriate use of the plural associated with a noun. A sentence completion task was performed in order to determine whether patients impaired on both sentence-picture matching and sentence judgment tasks are also compromised in their expression of quantifiers. Some patients impaired on both tasks also had difficulty expressing quantifiers, and it is these patients who may have difficulty performing grammatical computations. Other patients were selectively impaired in their sentence-picture matching or their sentence judgments, suggesting a performance deficit concerned with a particular task. We conclude that sentence comprehension impairments in PD are multifactorial in nature.     

Child and adolescent psychopathology research: Problems and prospects for the 1990s

In November 1990 the National Institute of Mental Health (NIMH) convened a special conference of over 100 scientists and leaders to outline specific strategies and research initiatives that should be developed to implement the recently released National Plan for Research on Child and Adolescent Mental Disorders.Participants included journal editors, educators from psychology and psychiatry, representatives from private foundations, and leaders of research program areas in public funding agencies. Critical knowledge gaps were identified in five areas of child and adolescent psychopathology, including depression, attention deficit hyperactivity disorder, conduct disorder, the anxiety disorders, and the developmental disorders. For each of these areas, special emphasis was placed on developing new ideas and obtaining critical input from other areas of investigation. This report summarizes the identified research gaps and recommends research initiatives to implement the National Plan, as outlined by the conference participants.     

Hypermnesia in free recall and cued recall

In three experiments, categorized lists and both free recall and cued recall tests were used to examine hypermnesia. In Experiment 1, materials were drawn from obvious and nonobvious categories in an attempt to vary the amount of relational processing at encoding. The study materials in Experiment 2 consisted of a long word list that comprised several exemplars from each of a number of common categories. In Experiment 3, a single exemplar was drawn from each of 45 categories. In each experiment, similar magnitudes of hypermnesia were obtained on free and cued recall tests. Examination of the specific items recalled across tests indicated that similar processes underlie the hypermnesic effect for both test conditions. Implications of the results for extant accounts of the hypermnesic effect are discussed. It is concluded that the dynamics of retrieval processes change in a systematic fashion across repeated tests and the retention interval following study and that an adequate account of the nature of these changes in retrieval dynamics is essential to our understanding of hypermnesia and related phenomena.     

Spatial and Selective Attention in the Cerebral Hemispheres in Depression, Mania, and Schizophrenia

Two tachistoscopic tests examining distinct aspects of attention were administered to normal subjects and patients with depression, mania, and schizophrenia. The first examined spatial attentional bias using happy-sad chimeric faces, known to elicit a perceptual bias to the left side of space in normal right-handers provided the right cerebral hemisphere is intact. The second used a lateralized version of the Stroop task, a traditional test of selective attention. Normals showed the expected leftward perceptual bias but showed equivalent susceptibility to the Stroop effect in both visual fields. As previously demonstrated with chimeric faces viewed in free vision, depression and mania were associated with weak and strong biases respectively with schizophrenics showing no bias to either side of space. The relationship between perceptual bias, as assessed by reaction time and absolute performance and the Stroop effect, showed differences according to diagnosis. This may be interpreted as evidence for the dissociability of attentional processes as well as lateralized differences in the pattern of cerebral activation in affective disorders and schizophrenia. The independence of performance variables on these tests in the schizophrenic group points to severe neuropsychological dysfunction.     

Women in advertisements in medical journals

To determine the images of women in picture advertisements, a stratified random sample of 32 medical journals, representing approximately 12% of medical journals published in the United States that are directed toward physicians in clinical practice, was subjected to content analysis. The sample consists of 209 different ads. The subjects of the ads included men, women, and children representing a variety of ethnic, racial, and socioeconomic groups. Notable, however, was the preponderance of Caucasian males pictured as physicians and the absence of women and people of color in this role. Women are pictured as 68.1% of consumers and men as 31.9%, a significant difference. Statistically significant differences also occur in the images of men and women as consumers. Most of the workers are men (68.2%), another significant difference. When women depicted are workers, they are secretaries and waitresses. Portrayals of women in medical advertisements continue to be stereotyped and outdated.     

Essentialism, Constructionism, and Feminist Psychology

This article attempts to clarify two alternative understandings of gender—the essentialist and the constructionist—and to discuss the implications of each for feminist psychology. Essentialist construals of gender, represented by recent "cultural feminist" positions, are critiqued for the theoretical, empirical, and political concerns they raise. A constructionist position is offered as ameliorative, and lingering questions raised by this analysis are discussed.     

The relationship of alcohol, tobacco, marijuana, and other illegal drug use to delinquency among Mexican-American, black, and white adolescent males

This study examined the relationship between drug use and delinquent behavior among 348 high school males (154 whites, 172 Mexican-Americans, and 22 blacks) and 89 adjudicated delinquent males confined to a maximum-security facility for violent and repeat offenders (37 whites, 25 Mexican-Americans, and 27 blacks). Data were collected in the spring of 1986 using self-administered questionnaires. Analyses were performed separately for each racial subgroup. Simple correlations revealed that self-reported alcohol, tobacco, marijuana, and other illegal drug use were all significantly related to both minor and violent delinquency for all three racial groups. Multiple regression analysis revealed that the use of these substances accounted for 40% to 47% of the variance in minor delinquency and for 59% of the variance in violent delinquency among blacks, 53% of the variance in violent delinquency among Mexican-Americans, and 34% of the variance in violent delinquency among whites. The best predictors of violent delinquency were the frequent use of illegal drugs other than marijuana and use of tobacco, in that order, among Mexican-Americans; the frequent use of other illegal drugs, marijuana, and tobacco, in that order, for whites; and the frequent use of illegal drugs, followed by marijuana, for blacks.