Nonsuicidal physically self-damaging acts in adolescents

To determine the frequency and correlates of nonsuicidal physically self-damaging acts in 12–14 year olds, a two stage epidemiologic survey with a self-administered questionnaire (N=3283) followed by a psychiatric interview of a subsample of the adolescents and their parents (N=444) was used. Prevalence estimates of interview validated nonsuicidal physically self-damaging acts were 2.46% in males and 2.79% in females. Significant relationships were found between nonsuicidal physically self-damaging acts and suicidal ideation, major depression and undesirable life events. Data suggest that physically self-damaging acts occur at substantial rates during early adolescence. The strong correlation between nonsuicidal self-destructive acts and both suicidal ideation and major depression clarifies prior conflicting reports in the literature and suggests that a history of self-damaging acts should be taken into consideration when evaluating for possible depression and suicide risk.     

MacLaboratory for Psychology: Successes,failures, economics,and outcomes over its decade of development

The history of the development of MacLaboratory for Psychology offers insights into both problems and solutions in academic software creation and implementation. Superficially, MacLaboratory for Psychology has been very successful, having garnered numerous acclamations, including two EDUCOM awards. It is used on thousands of Macintoshes at universities, hospitals, schools, and other institutions worldwide. However, there have also been some shortcomings to its use. In a candid discussion, successes, failures, the economics of software development, and student outcomes are addressed. Specific examples from the software as it has been used by over 10,000 undergraduates at Drexel University provide guidelines for future academic software in such domains as multimedia use, psychological and scientific education, classroom implementation, faculty research, and software support and maintenance.     

Lotus 1-2-3 simulation of frequency encoding on the basilar membrane

A spreadsheet simulation was designed to describe frequency encoding on the basilar membrane according to the place theory (Greenwood, 1961). For any given frequency, the simulation displayed the location of maximum amplitude on the basilar membrane and the relevant critical bandwidth. The authors found a very high correlation between data given by the simulation and data from empirical research. The high correlation indicates the validity of the place theory of frequency encoding and the usefulness of this simulation for future research purposes.     

Practices and representations of child care and motor development among West Africans in Paris

Massage techniques and postural manipulation used by West African women immigrants in Paris were studied, with the aim of demonstrating that culturally regulated caretaking practices have an influence on infant motor development. Twenty-five infants were observed between the ages of 3 and 12 months and 9 and 15 months. Frequency of massage and its accompanying set of physical exercises were found to be related to age at onset of independent walking. The findings show that infants receiving daily massage walk significantly earlier than infants who do not receive massage, thus confirming other reports that vestibular and postural stimulation have a positive effect on motor development. These results are discussed in relation to the observed frequencey of contact and of physical games with the caregiver for a smaller sample of three infants, and to parental expectations about the age of acquisition of certain cognitive and motor abilities. African immigrant mothers expect their infants to sit and to walk earlier than French mothers. The conclusion emphasizes the contribution of social anthropology, which shows that in all cultures, physical development and body changes elicit symbolic practices and a search for explanation.     

An X Windows tool for synthesizing face images from eigenvectors

An X Windows software tool for the construction of faces with a weighted combination of eigenvectors is described. The eigenvectors were extracted from an autoassociative matrix that comprised 100 face images. The program input consists of eigenvectors and sets of weights that describe individual faces and combines these to create face images. The tool creates a panel of buttons that permits the display of individual eigenvectors and the display of an average face as well. Facilities for on-line changes to the intensity of individual eigenvectors can be used to change the appearance of a face. Previously, O’Toole, Abdi, Deffenbacher, and Bartlett (1991) have shown that the intensity of certain individual eigenvectors contains reliable information for determining the sex and race of the face.     

Evaluating student achievement with a relational database

Commercial database programs such as dBase and Paradox, although developed originally for business applications, are versatile and powerful tools that can be used for an academic purpose such as evaluating student performance. They can be used to write and store test questions, assemble and print classroom or on-line laboratory tests, and calculate grades, test statistics, and so forth. Databases are flexible, unlike textbook “ancillary” test bank programs that are inextricably bound to the strictly linear format and brief shelf life of specific textbook editions. A prototypical relational database program is described, with which an instructor can produce tests based on generic terms adapted from Boneau’s (1990) study of psychological literacy, as well as on behavioral learning objectives adapted from Bloom’s (1956) taxonomy of educational objectives. As a relational database, the program integrates terms, objectives, questions, tests, and test scores, and avoids unnecessary data duplication and waste of computer storage space.     

Shape from stereo: A systematic approach using quadratic surfaces

We used quadratic shapes in several psychophysical shape-from-stereo tasks. The shapes were elegantly represented in a 2-D parameter space by the scale-independentshape index and the scale-dependentcurvedness. Using random-dot stereograms to depict the surfaces, we found that the shape of hyperbolic surfaces is slightly more difficult to recognize than the shape of elliptic surfaces. We found that curvedness (and indirectly, scale) has little or no influence on shape recognition.     

Hemispheric differences in the interference among components of compound gratings

The relationship between local/global and high/low spatial-frequency processing in hemispheric asymmetries was explored. Subjects were required to judge the orientation of a high- or low-spatial-frequency component of a compound grating presented in the left visual field (LVF) or right visual field (RVF). In Experiment 1, attention was focused on one or the other component. A signal detection analysis indicated that sensitivity (d′) to the high-spatial-frequency target was reduced more by the presence of the low-spatial-frequency component when both were presented in the LVF rather than in the RVF. In Experiment 2, subjects determined whether a target orientation was present, independent of spatial frequency at only a single level (i.e., at the high- or low-spatial-frequency level), as opposed to both or neither level. An RVF/LH (left hemisphere) advantage was found when the decision was based on the orientation of the high-frequency component. The asymmetrical influence of visual field of presentation and spatial frequency upon sensitivity is discussed in terms of hemispheric differences in the magnitude of inhibition between spatial-frequency channels and in the role of transient channel activity to capture and direct higher order attentional processes.