A neural activity interpretation of luminance effects on infant pattern preferences

Visual pattern preferences were established for 9- and 13-week-old infants (N = 96) using stimuli varying in contour density presented either at a low, moderate, or high luminance level. Age differences in the maximally preferred patterns across stimuli and luminance levels indicated that luminance interacts with contour density in determining stimulus preference functions for a given age. A neural activation model based on synchronous neural activity was advanced to describe these results.     

A psychoanalytic reinterpretation of the effectiveness of systematic desensitization: Fact or fiction?

Silverman, Frank and Dachinger (1974) found support for their hypothesis that the effectiveness of systematic desensitization (SD) resides in its activation of unconscious, merging fantasies. Their subjects were subjected to a variant of SD. in which a procedure aimed at stimulating a fantasy of ‘merging with mother’ was substituted for muscle relaxation. This pro- cedure consisted of the tachistoscopic subliminal exposure of the symbiotic gratification stimulus mommy and i are one(experimental) or neutral stimulus people walking (control). The aim of the present study was to replicate their work with special reference to demand characteristics. using as subjects snake phobics. SD with a symbiotic gratification stimulus was not more effective than SD with a neutral stimulus, which may be explained by the fact that the neutral stimulus in the present study snake and I are one was more relevant than the neutral stimulus in the Silverman et al. study. Moreover, subjects with a therapy-set improved significantly more than subjects with a research-set.     

The effects of aversive conditioned stimuli on the timing of unsignalled avoidance responding in rats

Rats received unsignalled avoidance training in a shuttlebox. After acquisition, classical conditioning sessions were administered. The Excitatory Group received signals paired with shock, the Inhibitory Group received signals explicitly unpaired with shock, while the Random Control Group received signals and shocks randomly in time. When subsequently superimposed on the avoidance baseline, the excitatory signal increased response rate, the inhibitory signal decreased rate and the random signal had no effect compared to signal-only control data. Unsignalled avoidance generates temporal gradients of responding; the major purpose of this study was to determine how these rate changes were reflected in the baseline temporal behavior. Very clear and simple summation rules emerged: In the presence of the excitatory signal, rats acted as if they were ahead of their actual location in the response-shock interval regardless of where the signal occurred; the inhibitory signal had the opposite effect while the random signal did not change the temporal behavior relative to signal-only control data. These results were interpreted within a motivational framework.     

Evaluating socioeconomic status bias in the WISC-R

The use of intelligence tests in making special education placement decisions for children has come under repeated scrutiny in recent years. Arguments for and against the use of IQs have centered around the issue of test bias. In California a permanent moratorium on the use of intelligence tests in placing minority group children into classes for the educable retarded has been handed down by the court. One defense proposed by advocates of mental testing has been that the tests are biased against socially and economically disadvantaged groups irrespective of race. According to Clarizio (1978), if a test predicts equally well for two groups it can not legitimately be described as biased. The purpose of this investigation was to evaluate the test bias of the Verbal IQ as measured by the Wechsler Intelligence Scale for Children-Revised in relation to predictions of academic achievement in two different socioeconomic status groups. The results indicated that Verbal IQs are not biased with respect to socioeconomic status. Derived regression equations are presented along with an analysis to inspect the statistical power of the original tests.     

Sex differences in the structure of intelligence: A confirmatory factor analysis

The LISREL model of Jöreskog and Sörbom was used to perform a comparative factor analysis on intelligence data from four sex by generation groups. The covariance matrices for 10 psychometric ability measures were used to isolate Spatial and Verbal Intelligence factors. Results from a series of factor analysis models indicated substantial invariance in the factor pattern and factor covariance matrices, although the hypothesis of complete invariance in factor pattern was rejected. The groups did differ in observed and unique variances. The results were basically consistent with the hypothesis that males and females have similar intellectual structure, which would have been obscured had standardized factor analysis been employed. There were also sex and generation differences in the Spatial and Verbal factor means.     

Cognitive correlates of map-reading ability

The performance of ROTC students on the Relief Format Assessment Test (RFAT) was regressed on psychometric variables and a measure of hemisphericity. Contrary to expectation, it was found that measures of visual-spatial ability and hemisphericity were not good predictors of map-reading ability, whereas the Extended Range Vocabulary and Mathematical Aptitude Tests were significant predictors. Factor analysis of the RFAT indicated the existence of two factors, one tentatively associated with terrain analysis and the other with altitude estimation. Mathematical Aptitude along with Form Board predicted performance on the altitude estimation factor, whereas Extended Range Vocabulary along with Similarities and Institution predicted performance on the terrain analysis factor. These results suggest that at least for our subjects, the solution of map-reading problems is primarily dependent upon verbal-analytic and to a lesser extent upon visual-spatial ability.     

Vibrotactual choice reaction time,tactile receptor systems and ideomotor compatibility

In most of the literature on human performance the results of an experiment by Leonard (1959) are quoted as the most outstanding example of perfect S-R-compatibility. In that experiment the fingertips were stimulated by a 50 Hz vibration; the vibrating armature had to be depressed and the reaction times of the right index finger were recorded. The reaction time was found not to increase with an increasing number of tactual choices. In experiment 1 of the present study, also applying 50 Hz vibrations, the reaction times of other fingers were also reported. In addition the response stimulus interval (RSI) was varied. Leonard's results were not replicated: reaction time increased with the number of tactual choices at all levels of RSI. In experiment 2 the frequency and amplitude of vibration were systematically varied and it turned out that these variables could account for the differences between the results found. An increase in reaction time with the number of tactual choices was found with weak vibrations, but not with strong vibrations. The differences in reaction time patterns appeared to be caused by differences in tactile receptor systems (i.e. the non-Pacini versus the Pacinian system). It was concluded that the concept of S-R-compatibility did not cover the pattern of results but that the concept of ideomotor compatibility did.     

Secondary school curriculum and career behavior in young adults

As part of a larger longitudinal study of the effects of secondary school characteristics on career behavior in young adulthood, this paper presents findings obtained from 1007 males and females who graduated from high school in academic or vocational curricula 6 or 8 years ago. Criterion behavior included the completion of career development tasks in the exploration and establishment life stages as measured by the Adult Form of the Career Development Inventory, certainty about immediate occupational plans, and satisfaction with occupational goals and progress toward meeting them. Significant differences were found in the pattern of career development by curriculum but not by sex, in certainty by curriculum and sex, and in satisfaction by neither curriculum nor sex. The implications for a stage theory of career development are discussed.     

Operating principles in repetitive babbling: A cognitive continuity approach

A case study of the period of repetitive babbling in one child (Dutch) is reported. A cognitive continuity theory is presented, which views repetitive babbling as a systematic, continuous and largely self-directed process of exploration, during which the child uses certain operating principles in the construction of his own ‘springboard’ to speech.Two operating principles identified are: a combination principle, consisting of the combining of articulatory acts which previously have been exercised separately, and a variation principle, consisting of the trying out of the same type of articulatory act in different articulatory contexts.Four stages are distinguished in the development of repetitive babbling. In the first stage no combinations occur, in the second stage combination mainly takes the form of repetition and in the third stage it takes the form of concatenating different babbling types as well. In the fourth stage the concatenations grow more varied and less repetitive in character. The subsequent stages of jargon babbling and first words are discussed shortly and their continuity with repetitive babbling is pointed out.