Theories About Black-White Interracial Marriage: A Clinical Perspective

Clinicians need to expose negative biases in theories about interracial relationships and direct the attention of couples and their families toward relationship strengths.     

Differential validity by sex in employment settings

The current study meta-analyzes 59 male-female pairs of validity coefficients obtained during revalidation of the General Aptitude Test Battery (GATB) for evidence of differential validity by sex. Results suggest that general cognitive ability may be slightly more predictive of rated job performance for women than for men in our sample of studies. Moderator analyses examined the effects of occupational sex-dominance and cognitive complexity. Results of these analyses indicate that, in single sex-dominated occupations, tests of general cognitive ability and perceptual ability are more valid for members of the dominant sex, and these differences are more apparent at low-complexity levels. Explanations for the findings are offered in terms of properties of the ratings criterion.An earlier version of this paper was given at the 2nd annual convention of the Society for Industrial and Organizational Psychology, Inc., Atlanta, GA. The authors thank Dave Synk for providing the occupation codes for each study.     

Components of phonemic processing and the beginning reader

This study primarily investigated various aspects of phonemic processing and memory in relation to reading in 74 5- and 6-year-old British children. A principal components analysis revealed a major connection between reading and aspects of phonemic processing for both age groups. For the 5-year-olds the processing of the initial phoneme was important for reading, whereas for the 6-year-olds processing of initial and final phonemes appeared to be equally related on this factor. A second factor for both groups was intelligence, which was related to reading only for the 6-year-olds; but this intelligence factor was more associated with phonemic processing for the 5-year-olds. An analysis involving clustering individual readers with similar patterns across the experimental variables showed some consistent profiles for disabled readers across the two age groups. These profiles suggested potential areas for remediation according to subgroup membership.     

Parallel distributed processing and neuropsychology: A neural network model of Wisconsin card sorting and verbal fluency

Neural networks can be used as a tool in the explanation of neuropsychological data. Using the Hebbian Learning Rule and other such principles as competition and modifiable interlevel feedback, researchers have successfully modeled a widely used neuropsychological test, the Wisconsin Card Sorting Test. One of these models is reviewed here and extended to a qualitative analysis of how verbal fluency might be modeled, which demonstrates the importance of accounting for the attentional components of both tests. Difficulties remain in programming sequential cognitive processes within a parallel distributed processing (PDP) framework and integrating exceedingly complex neuropsychological tests such as Proverbs. PDP neural network methodology offers neuropsychologists co-validation procedures within narrowly defined areas of reliability and validity.     

Heart rate--QT relationships during baroreceptor stimulation with diminished autonomic influence on the ventricles. Ventricular autonomic tone and QT interval.

The shortening of the QT interval of the electrocardiogram coincident with acceleration of heart rate and vice versa has been accepted for many years as evidence that the action potential duration and hence QT are necessarily dependent on heart rate. Exceptions to this rule have been attributed to the intervention of counteracting autonomic effects. In order to test this assumption, 26 conscious dogs divided into three groups were tested during baroreceptor stimulation by a bolus injection of phenylephrine. Seventeen dogs had been used in earlier studies in which they had undergone an experimental anterior myocardial infarction with apparent full recovery. A group of those dogs underwent beta-adrenergic blockade by intravenous atenolol 30 min prior to the baroreceptor activation. To test the intactness of the baroreceptor responses in the previously infarcted dogs, a third group of nine dogs that had had no prior myocardial infarction was included. All dogs were adapted to the laboratory environment and were not sedated during experiments. Simultaneous recordings of RR, QT interval, and phasic arterial pressure were made in all dogs before and during baroreceptor stimulation. In the normal group, and the previously infarcted group that received no atenolol, baroreceptor stimulation elicited a small (8/msec), but significant prolongation of the QT associated with a nearly 50% reduction in heart rate. The QT interval of the atenolol-treated dogs, although significantly more prolonged before stimulation, remained unchanged during the reflex. The data indicate that withdrawal of ventricular sympathetic tone may prolong the QT interval, thereby confirming the role of sympathetic innervation in the control of QT.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cocaine-induced brainstem seizures and behavior.

A variety of abnormal sensory/motor behaviors associated with electrical discharges recorded from the bilateral brainstem were induced in adult WKY rats by mechanical (electrode implants) and DC electrical current stimulations and by acute and chronic administration of cocaine. The electrode implant implicated one side or the other of the reticular system of the brainstem but subjects were not incapacitated by the stimulations. Cocaine (40 mg/kg) was injected subcutaneously for an acute experiment and subsequent 20 mg/kg doses twice daily for 3 days in a chronic study. Cocaine generated more abnormal behaviors in the brainstem perturbation group, especially the electrically perturbated subjects. The abnormal behaviors were yawning, retrocollis, hyperactivity, hypersensitivity, "beating drum" behavior, squealing, head bobbing, circling, sniffing, abnormal posturing, and facial twitching. Shifts in the power frequency spectra of the discharge patterns were noted between quiet and pacing behavioral states. Hypersensitivity to various auditory, tactile, and visual stimulation was present and shifts in the brainstem ambient power spectral frequency occurred in response to tactile stimulation. These findings suggest that the brainstem generates and propagates pathological discharges that can be elicited by mechanical and DC electrical perturbation. Cocaine was found to activate the discharge system and thus induce abnormal behaviors that are generated at the discharge site and at distant sites to which the discharge propagates. Cognitive functions may also be involved since dopaminergic and serotonergic cellular elements at the brainstem level are also implicated.