Accuracy and speed of orthographic processing in persons with developmental dyslexia

A group of 39 persons (20 male and 19 female, 11.0 to 32.5 yr.) with developmental dyslexia and 42 controls (21 male and 21 female, 11.2 to 32.3 years) were compared on computerized tests of sight word reading, nonword decoding, and spelling recognition. The subjects with developmental dyslexia performed significantly slower and less accurately than controls on all tasks. Further, the effect size of the group differences was larger for the older group. Within-group analyses showed a significant difference by age group on accuracy. Only the control group showed a significant age difference between groups on response time. Mean accuracy and response times for the reading-disabled subjects resembled shifted versions of the control group means. These results agree with previous reports that phonological deficits persist for reading-disabled adults and suggest a test of whether the discrepancy between reading-disabled and typically achieving readers may actually increase across age groups.     

Test of the definition of learning disability based on the difference between IQ and achievement

A learning disability is commonly defined as a discrepancy between IQ and achievement. This has been criticized for identifying too many children as having a learning disability who have high IQs and average academic achievement. Such overidentification as actually occurred was assessed in 473 referred children (8-16 years, M= 10, SD=2) with normal intelligence. Learning disability was defined as a significant discrepancy (p<.05) between predicted and obtained achievement in reading, mathematics, or written expression on the Wechsler Individual Achievement Test. Predicted achievement was based on the child's WISC-III Full Scale IQ. Overidentification was considered to occur when a child scored at or above age level in reading, mathematics, and writing but still had a significant discrepancy between predicted and obtained achievement by virtue of a high IQ. Learning disability was diagnosed in 312 (66%) of the children. There was no overidentification because all children had one or more WIAT scores below the normative level for their age, i.e., < 100. Further, only 7% of the children were identified with a learning disability based on a WIAT score in the 90s. These children had a mean IQ of 123 and were rated by their teachers and parents as having learning problems.     

Linguistic cues enhance the learning of perceptual cues

When language is correlated with regularities in the world, does it enhance the learning of these regularities? This question lies at the core of both notions of linguistic bootstrapping in children and the Whorfian hypothesis. Support for an affirmative answer is provided in an artificial-noun-learning task in which 2-year-old children were taught to distinguish categories of solid and nonsolid things with and without supporting correlated linguistic cues.     

Differential relationships between intergroup contact and affective and cognitive dimensions of prejudice

Research on affective dimensions of intergroup relationships suggests that positive effects of intergroup contact can generalize through establishing affective ties with outgroup members. However, research on cognitive dimensions emphasizes that it is often difficult to generalize positive contact outcomes. In this research, the authors examine whether affective and cognitive dimensions of prejudice bear different relationships to intergroup contact. Using data from a larger meta-analysis of contact effects, Study 1 demonstrates that affective indicators of prejudice typically yield stronger, inverse contact-prejudice relationships than such cognitive indicators as stereotypes. Study 2 replicates these trends in a survey study using multiple indicators of affective and cognitive dimensions of prejudice. Study 2 also shows significant, inverse relationships between contact and affective prejudice when contact is assessed either as number of outgroup friends or intergroup closeness. Together, these results suggest that affective dimensions of intergroup relationships are especially critical for understanding the nature of contact-prejudice effects.     

IQ decline following early unilateral brain injury: a longitudinal study

We examine whether children with early unilateral brain injury show an IQ decline over the course of development. Fifteen brain injured children were administered an IQ test once before age 7 and again several years later. Post-7 IQ scores were significantly lower than pre-7 IQ scores. In addition, pre-7 IQ scores were lower for children with larger lesions, but children with smaller lesions and higher pre-7 IQ scores showed a greater IQ decline over time. These findings suggest that the cognitive outcomes of children with early lesions, particularly those with relatively small lesions, change over the course of development.     

Understanding of the concept of numerically "less" by bottlenose dolphins (Tursiops truncatus)

In 2 experiments, bottlenose dolphins (Tursiops truncatus) judged the ordinal relationship between novel numerosities. The dolphins were first trained to choose the exemplar with the fewer number of items when presented with just a few specific comparisons (e.g., 2 vs. 6, 1 vs. 3, and 3 vs. 7). Generalization of this rule was then tested by presenting the dolphins with all possible pairwise comparisons between 1 and 8. The dolphins chose the exemplar with the fewer number of items at levels far above chance, showing that they could recognize and represent numerosities on an ordinal scale. Their pattern of errors was consistent with the idea of an underlying analog magnitude representation.     

A Meta-Analysis of Cognitive Deficits in Adults with a Diagnosis of Schizophrenia

This review identified 1275 studies examining cognitive deficits in people with schizophrenia, published between 1990 and 2003. Data from 113 studies (4365 patients and 3429 controls) were combined in a meta-analysis carried out on the five cognitive domains of IQ, memory, language, executive function, and attention. Studies were excluded where they lacked a suitable control group or failed to present complete information. In all five cognitive domains, analysis indicated a consistent trend for patients to perform more poorly than healthy controls, with significant heterogeneity across studies. Sources of heterogeneity were analyzed and a need to ensure more appropriate composition of patient and control groups and to adopt a more refined and methodologically correct, hypothesis-driven approach was identified.     

Using data augmentation to obtain standard errors and conduct hypothesis tests in latent class and latent transition analysis

Latent class analysis (LCA) provides a means of identifying a mixture of subgroups in a population measured by multiple categorical indicators. Latent transition analysis (LTA) is a type of LCA that facilitates addressing research questions concerning stage-sequential change over time in longitudinal data. Both approaches have been used with increasing frequency in the social sciences. The objective of this article is to illustrate data augmentation (DA), a Markov chain Monte Carlo procedure that can be used to obtain parameter estimates and standard errors for LCA and LTA models. By use of DA it is possible to construct hypothesis tests concerning not only standard model parameters but also combinations of parameters, affording tremendous flexibility. DA is demonstrated with an example involving tests of ethnic differences, gender differences, and an Ethnicity x Gender interaction in the development of adolescent problem behavior.     

Extending neuropsychological assessments into the primary mental ability space

A battery of 17 neuropsychological tests (including the CERAD battery) and 17 psychometric ability tests were administered to a sample of 499 participants of the Seattle Longitudinal study who had been given the psychometric ability tests seven and 14 years earlier. The neuropsychological tests were projected into a 5-factor psychometric ability space by means of extension analysis. The concurrent regressions of the neuropsychology tests on the psychometric ability tests were then used to estimate neuropsychology test scores from the psychometric ability tests administered in 1984, 1991 and 1998. Neuropsychologists then rated the study participants as either normal, suspect or cognitively impaired in 1998. Changes in estimated test scores were computed over seven and fourteen years. Significant odds ratios between normal and cognitively impaired groups were found for all neuropsychological tests over the proximal period and for most tests over the 14-year period. Similar findings occurred for the odds ratios between the normal and suspect groups for the most proximal 7-year changes.     

A comparative study of values and attitudes of inner-city and middle-class postpartum women

This study compared postpartum women from the inner city (n = 94) and postpartum women from the urban middle class (n = 80) on values and goals for themselves and their newborn children. Terminal values of inner-city women for themselves related more to social and religious goals in contrast to the more intrapersonal and personal goals of middle-class women. Instrumental values of inner-city women for their newborn children demonstrated concern with conformity and control, whereas for the middle class there was more concern with competence. Goals for the near future of the inner-city mothers were based on a desire for jobs and education.