Construct Validity of Raven's Advanced Progressive Matrices for African and Non‐African Engineering Students in South Africa

We test the hypothesis that the Raven's Advanced Progressive Matrices has the same construct validity in African university students as it does in non‐African students by examining data from 306 highly select 17‐ to 23‐year olds in the Faculties of Engineering and the Built Environment at the University of the Witwatersrand (177 Africans, 57 East Indians, 72 Whites; 54 women, 252 men). Analyses were made of the Matrices scores, an English Comprehension test, the Similarities subscale from the South African Wechsler Adult Intelligence Scale, end‐of‐year university grades, and high‐school grade point average. Out of the 36 Matrices problems, the African students solved an average of 23; East Indian students, 26; and White students, 29 (p<.001), placing them at the 60th, 71st, and 86th percentiles, respectively, and yielding IQ equivalents of 103, 108, and 118 on the 1993 US norms. The same pattern of group differences was found on the Comprehension Test, the Similarities subscale, university course grades, and high‐school grade‐point average. The items on the Matrices ‘behaved’ in the same way for the African students as they did for the non‐African students, thereby indicating the test's internal validity. Item analyses, including a confirmatory factor analysis, showed that the African/non‐African difference was most pronounced on the general factor of intelligence. Concurrent validity was demonstrated by correlating the Matrices with the other measures, both individually and in composite. For the African group, the mean r=.28, p<.05, and for the non‐African group, the mean r=.27, p<.05. Although the intercepts of the regression lines for the two groups were significantly different, their slopes were not. The results imply that scores on the Raven's Matrices are as valid for Africans as they are for non‐Africans.     

Children with Specific Language Impairment are not impaired in the acquisition and retention of Pavlovian delay and trace conditioning of the eyeblink response

Three converging lines of evidence have suggested that cerebellar abnormality is implicated in developmental language and literacy problems. First, some brain imaging studies have linked abnormalities in cerebellar grey matter to dyslexia and specific language impairment (SLI). Second, theoretical accounts of both dyslexia and SLI have postulated impairments of procedural learning and automatisation of skills, functions that are known to be mediated by the cerebellum. Third, motor learning has been shown to be abnormal in some studies of both disorders. We assessed the integrity of face related regions of the cerebellum using Pavlovian eyeblink conditioning in 7–11 year-old children with SLI. We found no relationship between oral language skills or literacy skills with either delay or trace conditioning in the children. We conclude that this elementary form of associative learning is intact in children with impaired language or literacy development.     

Is auditory discrimination mature by middle childhood? A study using time‐frequency analysis of mismatch responses from 7 years to adulthood

Behavioural and electrophysiological studies give differing impressions of when auditory discrimination is mature. Ability to discriminate frequency and speech contrasts reaches adult levels only around 12 years of age, yet an electrophysiological index of auditory discrimination, the mismatch negativity (MMN), is reported to be as large in children as in adults. Auditory ERPs were measured in 30 children (7 to 12 years), 23 teenagers (13 to 16 years) and 32 adults (35 to 56 years) in an oddball paradigm with tone or syllable stimuli. For each stimulus type, a standard stimulus (1000 Hz tone or syllable [ba]) occurred on 70% of trials, and one of two deviants (1030 or 1200 Hz tone, or syllables [da] or [bi]) equiprobably on the remaining trials. For the traditional MMN interval of 100–250 ms post-onset, size of mismatch responses increased with age, whereas the opposite trend was seen for an interval from 300 to 550 ms post-onset, corresponding to the late discriminative negativity (LDN). Time-frequency analysis of single trials revealed that the MMN resulted from phase-synchronization of oscillations in the theta (4–7 Hz) range, with greater synchronization in adults than children. Furthermore, the amount of synchronization was significantly correlated with frequency discrimination threshold. These results show that neurophysiological processes underlying auditory discrimination continue to develop through childhood and adolescence. Previous reports of adult-like MMN amplitudes in children may be artefactual results of using peak measurements when comparing groups that differ in variance.     

Models for choice-reaction time

In the two-choice situation, the Wald sequential probability ratio decision procedure is applied to relate the mean and variance of the decision times, for each alternative separately, to the error rates and the ratio of the frequencies of presentation of the alternatives. For situations involving more than two choices, a fixed sample decision procedure (selection of the alternative with highest likelihood) is examined, and the relation is found between the decision time (or size of sample), the error rate, and the number of alternatives.     

Suitability of published neuropsychological test norms for urban African secondary school students in South Africa

Variations in neuropsychological test performance as a function of ethnic/cultural group membership, socioeconomic and educational status are widely documented. In South Africa, issues of cultural difference, sociopolitical disadvantage, cognitive and educational limitations, are of particular relevance. Accordingly, this study investigated the performance on a neuropsychological test battery of urban African high school students. A group of 100 Soweto students in Grades 8–12, and a second group of 152 sixth grade Soweto students aged 13–15 years, scored significantly lower on most of the measures than their American counterparts, as reflected in published norms. Results also demonstrated a significant difference in test performance as a function of educational grade. The findings confirmed the need for using norms and approaches which are appropriate to a given population when interpreting and addressing neuropsychological test performance.     

Atypical long-latency auditory event-related potentials in a subset of children with specific language impairment

It has been proposed that specific language impairment (SLI) is the consequence of low-level abnormalities in auditory perception. However, studies of long-latency auditory ERPs in children with SLI have generated inconsistent findings. A possible reason for this inconsistency is the heterogeneity of SLI. The intraclass correlation (ICC) has been proposed as a useful statistic for evaluating heterogeneity because it allows one to compare an individual's auditory ERP with the grand average waveform from a typically developing reference group. We used this method to reanalyse auditory ERPs from a sample previously described by Uwer, Albrecht and von Suchodoletz (2002). In a subset of children with receptive SLI, there was less correspondence (i.e. lower ICC) with the normative waveform (based on the control grand average) than for typically developing children. This poorer correspondence was seen in responses to both tone and speech stimuli for the period 100-228 ms post stimulus onset. The effect was lateralized and seen at right- but not left-sided electrodes.     

Performance on Raven's Matrices by African and White University Students in South Africa

Untimed Raven's Standard Progressive Matrices (SPM) were administered to 309 17- to 23-year-old students at the University of the Witwatersrand and the Rand Afrikaans University in Johannesburg, South Africa (173 Africans, 136 Whites; 205 women, 104 men). African students solved an average of 44 of the 60 problems whereas White students solved an average of 54 of the problems (p<.001). By the standards of the 1993 US normative sample, the African university students scored at the 14th percentile and the White university students scored at the 61st percentile (IQ equivalents of 84 and 104, respectively). The African–White differences were found to be greater on those items of the SPM with the highest item–total correlations, indicating a difference in g, or the general factor of intelligence. A small sex difference favoring males was found in both the African and the White samples, but unrelated to g.     

Back to Basics: The Psychoanalytic Conceptualization of Motivation

Reconsideration of motivation, a fundamental concept in psychoanalytic theory, engages us with basic assumptions and postulates of our field and draws us to the borders with neighboring scientific elaborations of the design, structure, and function of the mind. This paper presents a concept of motivation from a perspective in modern conflict theory and correlates this concept with current thinking in evolutionary biology. The challenges that this correlation raises for all psychoanalytic approaches to motivation are discussed. Natural selection has fundamentally organized motivation in accord with the principle of inclusive fitness. Adaptive motivations of self-interest achieved through social success are paramount. In mind sciences there is a growing appreciation of the innately modular mind with mounting evidence for domain and content-specific evolved psychological mechanisms, the modern term for instincts. In regard to motivation in modern conflict theory, evolved mechanisms and predispositions are innately linked to pleasure–unpleasure and include, importantly, motivations of self-interest. The pleasure–unpleasure principle regulates motivation throughout life. Early mother–child interactions are vital to the development and contextualization of motivation; however, these interactions themselves depend on mutually coadapted mechanisms that give vectors and impose constraints on every primary relationship. In evading innate contributions there is a danger of embarking on a new creationist paradigm.     

Effectiveness of students and parents in a psycho-educational intervention programme for children with learning problems

This study investigated the effects of involving two sources of ‘non-traditional manpower’ — namely, university students and parents — in a programme of psycho-educational intervention. It was predicted that, while intervention for children with learning problems would produce significant changes in their perceptions in relation to their families, in their scholastic skills and in their adjustment, the additional involvement of their parents would lead to even greater changes. To test this prediction, 36 children referred to a university Education Clinic were randomly divided into three equal-sized groups: youth counselling plus parent counselling (E₁), youth counselling (E₂), and a control group (C). While the hypothesised changes following intervention were not statistically demonstrated, clinical data did yield support for the effectiveness and potential value of the intervention programmes.     

Duration of auditory sensory memory in parents of children with SLI: a mismatch negativity study

In a previous behavioral study, we showed that parents of children with SLI had a subclinical deficit in phonological short-term memory. Here, we tested the hypothesis that they also have a deficit in nonverbal auditory sensory memory. We measured auditory sensory memory using a paradigm involving an electrophysiological component called the mismatch negativity (MMN). The MMN is a measure of the brain's ability to detect a difference between a frequent standard stimulus (1000 Hz tone) and a rare deviant one (1200 Hz tone). Memory effects were assessed by varying the inter-stimulus interval (ISI) between the standard and deviant. We predicted that parents of children with SLI would have a smaller MMN than parents of typically developing children at a long ISI (3000 ms), but not at a short one (800 ms). This was broadly confirmed. However, individual differences in MMN amplitude did not correlate with measures of phonological short-term memory. Attenuation of MMN amplitude at the longer ISI thus did not provide unambiguous support for the hypothesis of a reduced auditory sensory memory in parents of affected children. We conclude by reviewing possible explanations for the observed group effects.