Epidemiology of Down syndrome

Down syndrome (DS) is the most commonly identified genetic form of mental retardation and the leading cause of specific birth defects and medical conditions. Traditional epidemiological studies to determine the prevalence, cause, and clinical significance of the syndrome have been conducted over the last 100 years. DS has been estimated to occur in approximately 1 in 732 infants in the United States, although there is some evidence that variability in prevalence of estimates exist among racial/ethnic groups. Progress has been made in characterizing the specific types of chromosome errors that lead to DS and in identifying associated factors that increase the risk of chromosome 21 malsegregation, i.e., advanced maternal age and recombination. Studies to examine the variability of the presence of specific DS-associated birth defects and medical conditions provide evidence for genetic and environmental modifiers. Here, we provide a brief survey of studies that address the current state of the field and suggest gaps in research that can soon be filled with new multidisciplinary approaches and technological advances.     

Processing of biological motion point-light displays by baboons (Papio papio)

Humans apply complex conceptual judgments to point-light displays (PLDs) representing biological motion (BM), but how animals process this kind of display remains uncertain. Four baboons (Papio papio) were trained to discriminate BM from nonbiological motion PLDs using an operant computerized test system. Transfer tests were given after training with novel BM stimuli representing humans or baboons (Experiment 1), with inverted PLDs (Experiment 2), and with BM stimuli in which body parts had been spatially disorganized (Experiment 3). Very limited transfer was obtained with the novel and inverted displays in Experiments 1 and 2, but transfer was much higher after spatial disorganization in Experiment 3. It is suggested that the baboons did not retrieve and interpret the articulated shape of the human or monkey body from the BM PLD stimuli, but rather focused their attention on the configural properties of subparts of the stimuli. Limits in perceptual grouping and restricted abilities in picture-object equivalence might explain why the baboons did not map BM PLD displays onto what they represent.     

Concordance among readers of self-help books about important ideas

Amount of agreement among readers about the relevant information in a self-help psychology book was measured to assess whether readers' choices are unique or overlapping. 15 men and 14 women attended two 1-hr. sessions in which they read and marked relevant information in the first 60 pages of a self-help psychology book. Comparison of the amount and pattern of marking across pages and lines on five specific pages showed that there was a statistically significant amount of agreement on which pages contained relevant ideas and which lines contained important concepts. There were no differences between men and women.     

The influence of unilateral and bilateral arm flexion versus extension on judgments: an exploratory case of motor congruence

Two experiments were conducted to examine how activation of the motivational systems of approach and withdrawal (arm flexion vs. extension) through 2 different bodily mechanisms (right arm vs. left arm) influenced participants' evaluations of neutral Chinese ideographs. Study 1 found that unilateral flexion on the right side and unilateral extension on the left side led to more positive evaluations than unilateral flexion on the left side and unilateral extension on the right side. Using bilateral movements, Study 2 found that simultaneous performance of a right-arm flexion and a left-arm extension led to more positive evaluations than a left-arm flexion and a right-arm extension. A motor congruence hypothesis was offered to account for these findings.     

Understanding print: early reading development and the contributions of home literacy experiences

This study explored the development of children's early understanding of visual and orthographic aspects of print and how this is related to early reading acquisition. A total of 474 children, ages 48 to 83 months, completed standardized measures of phonological awareness and early reading skills. They also completed experimental tasks that tapped their understanding of what constitutes "readable" print. The parents of participants completed a questionnaire regarding their children's home literacy experiences. The data showed systematic development in children's understanding of print conventions and English orthography and spelling. Regression analyses indicated that print knowledge was related to early reading skill, even after accounting for variance due to age and phonological awareness. Furthermore, parents' ratings of the extent of their children's involvement in activities that led to practice in reading and writing most consistently predicted the development of emerging literacy skills, including understanding of the conventions of the English writing system. Little relation between print knowledge and the frequency of storybook reading by adults was observed.     

An estimate of the Flynn Effect: changes in IQ and subtest gains of 10-yr-old French children between 1965 and 1988

The significant increase in IQ in the industrialised countries during recent decades, known as the eponymous Flynn Effect, tends to be given numerous explanations (progress in schooling, television, nutrition, etc.). One way of studying this effect consists of assessing in which subtests the change in IQ takes place. Using the comparison among 120,000 French children on an intelligence test in 1965 and the results of 8640 children on the same test in 1988, Greenfield's hypothesis is discussed: that television and other media using graphical representations have induced an improvement in spatial and visual capacities to the detriment of capacities relating to vocabulary. The results are compatible with Greenfield's hypothesis, although other explanations are still possible.     

Effect of grammatical gender on visual word recognition: evidence from lexical decision and eye movement experiments

Lexical decision times and eye movements were recorded to determine whether grammatical gender can influence the visual recognition of isolated French nouns. This issue was investigated by assessing the use of two types of regularities between a noun's form and its gender--namely ending-to-gender regularities (e.g., the final letter sequence -at appears only in masculine nouns and, thus, is predictive of masculine gender) and gender-to-ending regularities (e.g., feminine gender would predict the final letter e, whereas masculine gender would not). Previous studies have shown that noun endings are used by readers when they have to identify gender. However, the influence of ending-to-gender predictiveness has never been investigated in a lexical decision task, and the effect of gender-to-ending regularities has never been evaluated at all. The results suggest that gender information can influence both the activation stage (Experiments 1 and 3) and the selection stage (Experiments 2 and 3) of the word recognition process.     

Science and Human Behavior translated into Portuguese: Ciência e Comportamento Humano

Science and Human Behavior was translated to Portuguese as part of the effort to begin a psychology course at the University of Brasília 40 years ago; one of the many results of the first visit of Fred S. Keller to Brazil. The book has been used continuously in undergraduate courses in Brazil since 1967.     

The BPQ: a scale for the assessment of borderline personality based on DSM-IV criteria

The aim of the study was to develop a self-report measure that assesses borderline personality traits as defined by DSM-IV criteria, including separate subscales for each criterion. A sample of normal subjects from community colleges in the midwestern region of the United States was used to develop the scale. The psychometric properties of the scale were examined using an additional United States sample and student samples from England and Australia. The scale was compared with existing measures of borderline and schizotypal personality. Evidence for the internal consistency and convergent and divergent validity of the new scale is presented. The results of several analyses of variance comparing males and females in the three national groups are reported. A Principal Components Analysis of the subscales suggested either a single factor or two correlated factors. Oblique rotation yielded a structure that distinguished identity/interpersonal and impulsivity borderline personality traits. It is concluded that the new scale provides a useful tool for clinicians and researchers interested in screening for borderline personality traits in both general and clinical populations. Suggestions for further research are indicated.