Knowledge is not everything: analysis of children's performance on a haptic comparison task

The relative effects of developmental level and domain-specific knowledge on children's ability to identify and make similarity decisions about object concepts based only on haptic (touch) information were investigated. Children aged 4-9 years with varying levels of dinosaur knowledge completed a cross-comparison task in which they haptically explored pairs of familiar (dinosaur) and unfamiliar (sea creature) models that varied in terms of their degree of differentiability. Older children explored models more exhaustively, found more differentiating features and consequently made fewer errors than younger children did. High knowledge enabled children to identify models correctly, but was also associated with the use of a hypothesis testing strategy, which led children to make greater numbers of "miss" errors on the cross-comparison task. Performance in the control domain illustrated that the hypothesis testing strategy was specific to the high knowledge domain. Potential explanations for the role of knowledge and development in haptic exploration are considered.     

Effects of mand-tact versus tact-only training on the acquisition of tacts

We sought to replicate and extend Carroll and Hesse's (1987) study of the acquisition of tacts by including participants with and without developmental disabilities. As in Carroll and Hesse, the present results showed that mand-tact training, rather than tact-only training, led to more rapid acquisition of tacts. Tacting on follow-up tests did not differ. In addition, our results show that mand-tact training established both verbal operants involved about as rapidly as tact-only training established only one verbal operant. DESCRIPTORS: verbal behavior, tact acquisition, mand-tact training, tact-only training, follow-up     

Towards an understanding of unique and shared pathways in the psychopathophysiology of ADHD

Most attention deficit hyperactivity disorder (ADHD) research has compared cases with unaffected controls. This has led to many associations, but uncertainties about their specificity to ADHD in contrast with other disorders. We present a selective review of research, comparing ADHD with other disorders in neuropsychological, neurobiological and genetic correlates. So far, a specific pathophysiological pathway has not been identified. ADHD is probably not specifically associated with executive function deficits. It is possible, but not yet established, that ADHD symptoms may be more specifically associated with motivational abnormalities, motor organization and time perception. Recent findings indicating common genetic liabilities of ADHD and other conditions raise questions about diagnostic boundaries. In future research, the delineation of the pathophysiological mechanisms of ADHD needs to match cognitive, imaging and genetic techniques to the challenge of defining more homogenous clinical groups; multi-site collaborative projects are needed.     

Characterizing the ADHD phenotype for genetic studies

The genetic study of ADHD has made considerable progress. Further developments in the field will be reliant in part on identifying the most appropriate phenotypes for genetic analysis. The use of both categorical and dimensional measures of symptoms related to ADHD has been productive. The use of multiple reporters is a valuable feature of the characterization of psychopathology in children. It is argued that the use of aggregated measures to characterize the ADHD phenotype, particularly to establish its pervasiveness, is desirable. The recognition of the multiple comorbidities of ADHD can help to isolate more specific genetic influences. In relation to both reading disability and conduct disorder there is evidence that genes may be involved in the comorbid condition that are different from pure ADHD. To date, progress with the investigation of endophenotypes for ADHD has been disappointing. It is suggested that extending such studies beyond cognitive underpinnings to include physiological and metabolic markers might facilitate progress.     

Neural correlates of evaluation associated with promotion and prevention regulatory focus

Higgins (1997, 1998) proposed two self-regulatory or motivational systems—one sensitive to gains (promotion) and one sensitive to losses (prevention). To examine the interaction of motivation and cognition, participants made good/bad or abstract/concrete judgments about concepts during fMRI scanning. After scanning, participants rated the extent to which each stimulus was good and bad and completed a questionnaire that measured promotion/prevention orientation. For each participant, contrast maps were generated representing the association between neural processing and stimulus valence (good/bad), and these factors were then regressed against participants’ promotion and prevention focus scores. For the good/bad but not for the abstract/concrete task, promotion focus was associated with greater activity in the amygdala, anterior cingulate, and extrastriate cortex for positive stimuli, and prevention focus was associated with activity in the same regions for negative stimuli; these results are consistent with the hypothesis that the way in which evaluative information is processed is influenced by individual differences in self-regulatory focus.     

The relative importance of task and contextual performance dimensions to supervisor judgments of overall performance

Although evidence supports the unique contribution of task performance and contextual performance to overall evaluations, little is known about the relative contribution that specific dimensions of contextual performance make to overall performance judgments. This study evaluated the extent to which supervisors consider task and contextual performance by using relative weights (J. W. Johnson, 2000) to statistically describe the relative importance of specific dimensions of each type of performance to overall performance ratings. Within each of 8 job families in a large organization, each of 4 dimensions of contextual performance made not only a unique contribution but a relatively important contribution to the overall evaluation. Evidence also supports the adaptive performance dimension of handling work stress as an aspect of contextual performance and job-task conscientiousness as an aspect of both task and contextual performance.     

A synthetic validity approach to testing differential prediction hypotheses

A new method is presented for conducting differential prediction analyses that makes it possible to test differential prediction hypotheses with adequate statistical power even when the sample size within a job or a job family is very small. This method, called synthetic differential prediction analysis, represents an application of the logic of synthetic validation to differential prediction analyses. The authors explain this new method and describe its application in a selection-system validation study conducted in a large organization.     

Equivalencies regarding the measurement and constructs of self-esteem and major life events in an Asian/Pacific islander sample

Construct, scalar, and functional measurement equivalencies of the Rosenberg Self-Esteem Scale (RSES) and Major Life Events checklist (MLE) and the constructs assessed were investigated across groups differentiated on Hawaiian/part-Hawaiian and non-Hawaiian (e.g., Caucasian, Filipino, Hispanic, Japanese, and mixed/2 or more) ethnicity and gender. Initial results from maximum likelihood factoring with promax rotation showed that RSES negatively worded Item 5 loaded with the positively worded Items 1, 2, 4, 6, and 7 on 1 of 2 factors for Hawaiian/part-Hawaiian female participants. Similarly, negatively worded Item 8 and the same positively worded items comprised 1 of 2 factors for non-Hawaiian male participants. For the other 2 Ethnicity x Gender groups, factors were respectively comprised of the 5 positively and 5 negatively worded RSES items. Construct equivalence or simple (2-factor) structure underlying the RSES was indicated across the 4 groups after Items 5 and 8 were excluded from a subsequent factoring procedure. Simple structure showed that Factor 1 comprised the positively worded Items 1, 2, 4, 6, and 7, and the remaining negatively worded Items 3, 9, and 10 loaded on Factor 2. Scalar equivalence of the self-esteem and major life events measures was supported by the statistical nonsignificance of the Major Life Events x Ethnicity x Gender interaction effect in multiple regression models. The consistency in the absolute size and direction of the intercorrelations between overall self-esteem, self-esteem Factors 1 and 2, and major life events variables indicated the functional equivalence of respective measures and constructs assessed. Measurement equivalency findings concerning the RSES and MLE, the constructs measured, and their utility versus caution against their use in multiethnic studies were discussed.