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15-Year developmental study on effects of severe undernutrition during infancy on subsequent physical growth and intellectual functioning.

This third 5-year follow-up on the effects of severe undernutrition during infancy on subsequent brain growth and intellectual development confirms the level of gross retardation of intellect in the undernourished group when compared with the controls. As the subjects are now 15-18 years of age this must be permanent. All but 5 of the undernourished group are now living in conditions comparable to the controls. Improved nutrition is manifest by catch-up in height, in that the mean difference between undernourished subjects and controls has decreased by 2-73 cm. Remarkably, the difference in head circumference has increased by 0-5 cm, the mean head circumference of the undernourished now being 2-8 cm less than that of the controls. The Bender Gestalt and Human Figure Drawing tests did not correlate with the intelligence tests, indicating a separate deficit of a marked disturbance of visual-motor perception in 17 of the undernourished subjects, in 9 of whom these tests were highly significant of minimal brain dysfunction (5 of the controls). In retrospect there is much evidence to suggest the controls were also suboptimal; 8 controls had abnormal electroencephalograms as did 6 of the undernourished group.

Adolescent↗

EEG and intelligence: relations between EEG coherence, EEG phase delay and power.

OBJECTIVE: There are two inter-related categories of EEG measurement: 1, EEG currents or power and; 2, EEG network properties such as coherence and phase delays. The purpose of this study was to compare the ability of these two different categories of EEG measurement to predict performance on the Weschler Intelligence test (WISC-R). METHODS: Resting eyes closed EEG was recorded from 19 scalp locations with a linked ears reference from 442 subjects aged 5-52 years. The Weschler Intelligence test was administered to the same subjects but not while the EEG was recorded. Subjects were divided into high IQ (> or = 120) and low IQ (< or = 90) groups. EEG variables at P<.05 were entered into a factor analysis and then the single highest loading variable on each factor was entered into a discriminant analysis where groups were high IQ vs. low.Q. RESULTS: Discriminant analysis of high vs. low IQ was 92.81-97.14% accurate. Discriminant scores of intermediate IQ subjects (i.e. 90 < IQ < 120) were intermediate between the high and low IQ groups. Linear regression predictions of IQ significantly correlated with the discriminant scores (r = 0.818-0.825, P < 10(-6)). The ranking of effect size was EEG phase > EEG coherence > EEG amplitude asymmetry > absolute power > relative power and power ratios. The strongest correlations to IQ were short EEG phase delays in the frontal lobes and long phase delays in the posterior cortical regions, reduced coherence and increased absolute power. CONCLUSIONS: The findings are consistent with increased neural efficiency and increased brain complexity as positively related to intelligence, and with frontal lobe synchronization of neural resources as a significant contributing factor to EEG and intelligence correlations. SIGNIFICANCE: Quantitative EEG predictions of intelligence provide medium to strong effect size estimates of cognitive functioning while simultaneously revealing a deeper understanding of the neurophysiological substrates of intelligence.

Adolescent↗

Sentences for testing speech intelligibility in noise.

A list of ten spoken Swedish sentences was computer edited to obtain new lists with exactly the same content of sound, but with new sentences. A noise was synthesized from the speech material by the computer to produce exactly the same spectrum of speech and noise. The noise was also amplitude modulated by a low frequency noise to make it sound more natural. This material was tested monaurally on 20 normal-hearing subjects. The equality in intelligibility of some of the lists was investigated. Repeated threshold measurements in noise showed a standard deviation of 0.44 dB when the learning effect was outbalanced. Only a small part of the learning effect was due to learning of the word material. Intelligibility curves fitted to the data points in noise and without noise showed maximum steepnesses of 25 and 10%/dB respectively. At constant signal to noise ratio (S/N) the best performance was achieved at a speech level of 53 dB.

Adolescent↗

Children with congenital hypothyroidism and their siblings: do they really differ?

OBJECTIVE: Although favorable outcome is typically described in follow-up studies of children with congenital hypothyroidism (CH) identified by newborn screening, IQ reductions and persistent cognitive deficits are still reported. These findings are accounted for by disease and treatment variables as well as methodologic factors including choice of comparison group. Although siblings are ideal because they control for genetic and environmental influences, by definition they have different ages when tested, which can also introduce bias. Because we followed children with CH and their siblings over an extended period of time, there were a number of occasions when both groups were tested at the same age. The purpose of this study was to compare the results of children with CH and their unaffected siblings at the same age and with the same test. METHODS: The sample consisted of 42 children with CH detected between 1975 and 1985 and their 42 siblings, all of whom were tested with the McCarthy or Wechsler Intelligence Scale for Children-Revised (WISC-R) intelligence tests. Nineteen pairs of children were evaluated at 6 years with the McCarthy, and 30 pairs of children were evaluated at 7 or 9 years with the WISC-R. Recorded for children with CH were disease etiology, bone age and thyroxine levels at diagnosis, age at onset of treatment, and starting dosage of levothyroxine. RESULTS: Paired t tests revealed that the CH group scored lower than siblings by 8.1 IQ points on the McCarthy and 6.2 points on the WISC-R. Factors contributing to the size of the CH-sibling IQ difference were (1) the etiology of hypothyroidism, reflecting the larger differences by those with athyreosis or an ectopic gland than dyshormonogenesis, and (2) the starting dosage of levothyroxine, with those initially treated with >or=8.2 microg/kg per day having smaller CH-sibling differences than those given lower starting doses. There were no effects of bone age, thyroxine levels at diagnosis, or age at treatment onset. CONCLUSION: Children with CH treated early in life due to newborn screening may have reduced IQ relative to siblings.

Case-Control Studies↗

Inadequacy of brief IQ measures in the classification of mentally retarded prisoners.

This study was designed to evaluate the use of the Slosson Intelligence Test (SIT) and a Wechsler Adult Intelligence Scale (WAIS) short form in determining the intellectual capacity and educational/treatment needs of mentally retarded offenders. The subjects were 52 male prisoners with borderline or retarded intellectual functioning. Their WAIS full-scale IQs were found to be significantly different from their WAIS short-form and SIT IQs. These results suggest that we must continue to use the full WAIS in evaluating mentally retarded offenders.

Adolescent↗

Issues in defining mental retardation.

Responses were made to MacMillan, Gresham, and Siperstein's (1993) criticisms of the new AAMR definition. The new AAMR definition does not raise the IQ limit and is not intended to increase the number of people considered to have mental retardation. There is no intent to change who is and who is not considered to have mental retardation. Instead, the intent is to change how people think about mental retardation: The old deficiency model is replaced with a new support model. MacMillan et al.'s criticisms are based on unfortunate misstatements of both the 1983 and the 1992 AAMR definitions of mental retardation and on misunderstandings of psychometric science. On the one hand, they argued that intelligence tests are culturally biased. On the other hand, they criticized the AAMR for not making greater use of inflexible IQ cutoffs in defining mental retardation. They misunderstood that cultural bias is an argument for, not against, flexibility in the interpretation of intelligence tests.

Attitude↗

Emotional adaptation of children undergoing bone marrow transplantation.

OBJECTIVE: To examine stress reactions and psychic adaptation of children aged 8-12 years in single-room treatment under isolation conditions after bone marrow transplantation (BMT). METHODS: The prospective longitudinal study included free diagnostic interviews and a large test battery. We used a mixture of projective tests questionnaires and an intelligence test (the German version of the revised Wechsler Intelligence Scale for Children) to evaluate different adaptation processes. RESULTS: The questionnaires clearly showed children's strong tendencies to adapt to the situation and to normalize their behaviour under isolation conditions. In contrast, the psychoanalytic interview and the projective tests demonstrated a very differentiated emotional adjustment: Before transplantation, coming to terms with the life-threatening situation was deferred. After transplantation, very intensive emotional examination of the situation and superficial adaptation (protective denial) were observed. CONCLUSIONS: It is very important to intensify the child's and the family's psychosocial support before admitting the child for hospital treatment. Family conflicts and neurotic developments should be regarded as risk factors for marked and potentially dangerous stress reactions.

Adaptation, Psychological↗

[Does intelligence make a difference? Spelling and phonological readiness in specific and nonspecific reading/spelling disabilities].

OBJECTIVES: In an investigation involving, 1800 second-to-fourth graders, the children were divided into three groups according to their reading and spelling achievement and the results of a nonverbal intelligence test: children with average achievement in oral reading and spelling, and those with poor achievements in both which were either discrepant or non-discrepant to their good-to-average scores on the intelligence test. METHODS: Results for all three groups on a number of spelling tests were compiled to assess two component spelling skills: phonological recoding and application of orthographical knowledge. RESULTS: Children with either specific or nonspecific reading and spelling disabilities performed at the same level of phonological recoding, while both groups were worse than younger children of average ability at the same spelling level. Children with IQ-discrepant reading and spelling disabilities hat, on the other hand, a certain advantage over children with the same number of difficulties in spelling but a lower IQ on tasks requiring a knowledge of orthography. Though particularly evident in the lower grades, this advantage declined with advancing grade level. Additional comparison of the three groups in tests of phonological awareness and other phonological skills revealed a similar pattern of great differences between the two groups of poor readers and spellers and the average children, but slight non-significant differences between children with IQ-discrepant and non-discrepant reading and spelling disabilities.

Age Factors↗

Evidence for the importance of openness to experience on performance of a fluid intelligence task by physically active and inactive participants.

The cross-sectional relationship between exercise training history and performance on a fluid intelligence test was examined. In addition, openness to experience was included as a potential trait-based contributor to predicting cognitive performance. Results supported past literature demonstrating that aerobically trained or active participants performed significantly better on the fluid intelligence task than aerobically untrained or inactive participants. Hierarchical regression analysis results revealed, as predicted, that openness to experience was a significant predictor of fluid intellectual performance. When entered into the hierarchical regression equation, openness to experience accounted for 16.0% of unique variance in Culture Fair Intelligence Test performance. By contrast, participants' exercise training history, which initially and significantly (p < .05) accounted for approximately 12.0% of the variance in cognitive performance, accounted for 5.0% (p > .05) after openness was entered. Participants were, on average, more open than inactive participants. Results are discussed in terms of the possible mechanisms aerobic exercise training and openness to experience share in regard to brain functioning and performance of fluid intelligence tasks. Future research is suggested that examines biological factors known to influence cognitive performance in exercise settings.

Adult↗

Rapid assessment of severe cognitive impairment in individuals with developmental disabilities.

BACKGROUND: Most standardized intelligence tests require more than 1 hour for administration, which is problematic when evaluating individuals with intellectual disabilities and developmental disabilities (IDDD), because a significant proportion of these individuals can not tolerate lengthy evaluations. Furthermore, most standardized intelligence tests are of limited usefulness for individuals with severe cognitive deficits because of floor effects. METHODS: A number of low-difficulty items were selected from standardized tests. A total of 271 participants with profound, severe, moderate and mild levels of cognitive impairment took part in this study. In the formative phase, 68 participants were evaluated with the selected items, and those items that differentiated between levels of cognitive impairment were retained in the battery. The instrument was then modified and standardized with an additional 203 participants. RESULTS: The instrument, referred to as the Rapid Assessment for Developmental Disabilities (RADD), required 10-25 min for administration. Internal reliability estimates from the RADD total score and from individual subtests satisfied conventional and rigorous statistical criteria (median alpha r = 0.93). The RADD total score was strongly correlated with the level of cognitive impairment (rho = 0.86). The RADD total score and individual subtests differentiated between all levels of cognitive impairment ( Wilks Lambda = 0.135, F(42,525.832) = 12.075, P < 0.001). Receiver operating characteristic curves indicated the instrument was particularly sensitive to the cognitive abilities of the most seriously impaired participants. CONCLUSIONS: The RADD, composed of low-difficulty items from published tests, is rapidly administered, assesses a wide range of cognitive skills and differentiates among all levels of cognitive impairment. The battery has clinical utility with populations exhibiting short attention spans because of its ability to quickly assess a wide range of cognitive abilities. The RADD also has research potential for the documentation of cognitive function in studies of individuals with IDDD.

Adolescent↗

On the neurobiology of creativity. Differences in frontal activity between high and low creative subjects.

The aim was to investigate the relationship between creativity and hemispheric asymmetry, as measured by regional cerebral blood flow (rCBF). Two groups, each consisting of 12 healthy male subjects, who got either very high or low scores on a creativity test, were pre-selected for the rCBF investigation. rCBF was measured during rest and three verbal tasks: automatic speech (Auto), word fluency (FAS) and uses of objects (Brick). State and trait anxiety inventories were answered after the rCBF measurements. Intelligence tests were also administered. It was predicted that highly creative subjects would show a bilateral frontal activation on the divergent thinking task (Brick), while low creative subjects were expected to have a unilateral increase. Calculations were made of differences in blood flow levels between the FAS and the Brick measurements in the anterior prefrontal, frontotemporal and superior frontal regions. In accordance with our prediction, repeated measure-ANOVAs showed that the creativity groups differed significantly in all three regions. The highly creative group had increases, or unchanged activity, while the low creative group had mainly decreases. The highly creative group had higher trait anxiety than the low creative group. On the intelligence tests the low creative group was superior both on logical-inductive ability and on perceptual speed, while the groups were equal on verbal and spatial tests. The results are discussed in terms of complementary functions of the hemispheres.

Adult↗

The effect od differential reinforcement of cautiousness in intellectual performance among the elderly.

The effects of differential reinforcement of cautiousness upon intellectual performance in the elderly were investigated employing 56 females and 32 males with a mean age of 73 years. Cautiousness was manipulated by systematically varying pre-test instruction conditions involving the reinforcement of two levels of risk and of response omission when taking the Primary Mental Abilities Test (PMA). Results suggest that performance in intelligence tests is much influenced by situational variables involving motivational components. Subjects exposed to low-risk conditions performed significantly better on cognitive tasks than those exposed to high-risk conditions only when they were able to exercise the option of responding or not responding to individual task items. Implications for a reconstruction of conventional intelligence measures are discussed.

Aged↗

Prognostic factors for life expectancy after penetrating head injury.

Survival curves were made for 190 World War II veterans with penetrating head injuries, and for 106 WW II veterans with peripheral nerve injuries who matched the subjects with head injuries with respect to age at injury, years of formal education, and preinjury intelligence-test score. The results indicated that penetrating head injury coupled with posttraumatic epilepsy shortened life expectancy in subjects who survived the early postinjury period, but that head injury alone did not. Educational level was also a significant variable independent of seizures: subjects with more education survived longer than those with less education. Age at injury and the difference between preinjury and postinjury intelligence-test scores did not predict survival status.

Adolescent↗

Generational changes on the draw-a-man test: a comparison of Brazilian urban and rural children tested in 1930, 2002 and 2004.

Although gains in generational intelligence test scores have been widely demonstrated around the world, researchers still do not know what has caused them. The cognitive stimulation and nutritional hypotheses summarize the several diverse potential causes that have been considered. This article analyses data for a sample of 499 children tested in 1930 and one equivalent sample of 710 children tested 72 years later, the largest gap ever considered. Both samples comprised children aged between 7 and 11 who were assessed by the Draw-a-Man test in the city of Belo Horizonte, Brazil. Further, one additional sample of 132 children was assessed in 2004 in a rural area very similar in several diverse factors to the 1930 urban sample. The results are consistent with both the cognitive stimulation and the nutritional hypotheses.

Age Factors↗

Assessment of blood donor privacy during health history interviews.

BACKGROUND: Given the personal nature of health history interviews, it is important to provide donors with both visual and auditory privacy. Privacy is affected by variables such as background noise, the use of visual screens, and the loudness of the donor's voice. STUDY DESIGN AND METHODS: In Phase I of this study, an interview station and waiting area were simulated. To measure auditory privacy, a speech intelligibility test was given to subjects with and without the use of a free-standing privacy screen and masking noise device. Phase II was a field trial designed to evaluate screens and masking noise. Background noise was measured during each blood collection operation, and donors completed a survey. RESULTS: In Phase I, speech intelligibility test scores ranged from 78 to 5.1 percent, depending on the type of visual screen and the number of masking noise devices used. In Phase II, with the use of screens, 94 percent of donors rated visual privacy as "good to excellent," compared with 74 percent who did so when no screens were used. At many blood drives, the background noise level exceeded the level of the masking noise. CONCLUSION: The use of visual screens increases donors' perception of visual privacy. The use of masking noise is effective only when the health history interview is conducted under conditions of low background noise levels.

Blood Donors↗

Intellectual differences of adult men related to age and physical fitness before and after an exercise program.

Fluid and crystalized intelligence differences among high-fit, young; high-fit, old; low-fit, young, and low-fit, old groups were investigated before and after an exercise program. The high-fit group had higher fluid intelligence than the low-fit group. Likewise, the young group scored higher than the old group. The four groups scored higher at the posttest on two of the fluid intelligence subtests of the Cattell Culture. Fair Intelligence Test. No differences were observed on crystallized intelligence. It is uncertain how biological factors and psychological changes, either individually or in combination, produce differences in cognitive functioning due to physical fitness.

Adult↗