Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “intelligence”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37Linked to original sources

The structure and measurement of intelligence.

One of psychology's outstanding successes has been the measurement of intelligence, and the demonstration that differences in intelligence, so measured, were due in large part of genetic factors. In recent years much work has been done to clarify the problem of the biological basis of these inherited differences, and work on the evoked potential in the EEG has generated important new findings in this field. We now know far more about intelligence, its inheritance, and its biological basis than we did even a few years ago.

Electroencephalography↗

The use of artificial neural networks to estimate speech intelligibility from acoustic variables: a preliminary analysis.

Previous research has used regression analysis to attempt to predict the intelligibility of hearing-impaired speakers from acoustic speech parameters. Improvement of prediction may be achieved by the use of computerized artificial neural networks to process mathematically the acoustic input variables as part of the intelligibility process. A preliminary scheme for estimating speech intelligibility from acoustic parameters using a neural network is outlined and preliminary data illustrate its use.

Adult↗

Intelligence related upper alpha desynchronization in a semantic memory task.

Recent evidence shows that event-related (upper) alpha desynchronization (ERD) is related to cognitive performance. Several studies observed a positive, some a negative relationship. The latter finding, interpreted in terms of the neural efficiency hypothesis, suggests that good performance is associated with a more 'efficient', smaller extent of cortical activation. Other studies found that ERD increases with semantic processing demands and that this increase is larger for good performers. Studies supporting the neural efficiency hypothesis used tasks that do not specifically require semantic processing. Thus, we assume that the lack of semantic processing demands may at least in part be responsible for the reduced ERD. In the present study we measured ERD during a difficult verbal-semantic task. The findings demonstrate that during semantic processing, more intelligent (as compared to less intelligent) subjects exhibited a significantly larger upper alpha ERD over the left hemisphere. We conclude that more intelligent subjects exhibit a more extensive activation in a semantic processing system and suggest that divergent findings regarding the neural efficiency hypotheses are due to task specific differences in semantic processing demands.

Adolescent↗

Reaction times and intelligence: a comparison of Chinese-American and Anglo-American children.

Chinese-American and Anglo-American school children were compared on a nonverbal test of intelligence (Raven's Progressive Matrices) and on twelve chronometric variables which measure the speed with which basic information processes (e.g. stimulus apprehension, decision, and discrimination) can be carried out. All of these tasks are correlated with psychometric intelligence. The two groups differed significantly on most of the variables, but the differences appear to be multidimensional and are not simply due to a group difference in psychometric intelligence, equivalent to about 5 IQ points in favour of the Chinese-Americans. The results are compared with those of Lynn and his colleagues on Bristish, Japanese, and Hong Kong children, and both consistencies and inconsistencies are found.

Asian↗

High "intelligence," low "IQ"? Speed of processing and measured IQ in children with autism.

The uneven profile of performance on standard assessments of intelligence and the high incidence of savant skills have prompted interest in the nature of intelligence in autism. The present paper reports the first group study of speed of processing in children with autism (IQ 1 SD below average) using an inspection time task. The children with autism showed inspection times as fast as an age-matched group of young normally developing children (IQ 1 SD above average). They were also significantly faster than mentally handicapped children without autism of the same age, even when these groups were pairwise matched on Wechsler IQ. To the extent that IT tasks tap individual differences in basic processing efficiency, children with autism in this study appear to have preserved information processing capacity despite poor measured IQ. These findings have implications for the role of general and specific cognitive systems in knowledge and skill acquisition: far from showing that children with autism are unimpaired, we suggest that our data may demonstrate the vital role of social insight in the development of manifest "intelligence."

Adolescent↗

Understanding the nature of the general factor of intelligence: the role of individual differences in neural plasticity as an explanatory mechanism.

The nature of the general factor of intelligence, or g, is examined. This article begins by observing that the finding of a general factor of intelligence appears to be inconsistent with current findings in neuroscience and cognitive science, where specific connections are argued to be critical for different intellectual abilities and the brain is argued to develop these connections in response to environmental stimuli. However, it is then observed that if people differed in neural plasticity, or the ability to adapt their connections to the environment, then those highly developed in one intellectual ability would be highly developed in other intellectual abilities as well. Simulations are then used to confirm that such a pattern would be obtained. Such a model is also shown to account for many other findings in the field of intelligence that are currently unexplained. A critical period for intellectual development is then emphasized.

Adolescent↗

Cortical evoked potential, personality, and intelligence.

The averaged cortical evoked potential (CEP) was measured from 296 male subjects in two studies and was correlated with scores on intelligence and personality tests. For both studies, auditory stimuli were used with bipolar electrode placement to the Cz and T3 scalp positions. In the first study, with 84 subjects, stimulus intensity was 95 dB (all dB readings re 20 muN/m2). Intelligence was measured with the Mill Hill Vocabulary Scale and personality with H. J. Eysenck's PEN questionnaire. The second study, with 212 subjects, used additional stimuli at 75 dB and 55 dB. Intelligence was measured with the Ravens Progressive Matrices. State anxiety and other state measures at the time of testing were also taken. Neither study found any relation between the CEP and IQ or personality. However, more bored subjects showed larger CEP amplitudes. The results are discussed in terms of Ertl's neural efficiency hypothesis and Eysenck's arousal theory of personality.

Acoustic Stimulation↗

Genetics of intelligence.

This article provides an overview of the biometric and molecular genetic studies of human psychometric intelligence. In the biometric research, special attention is given to the environmental and genetic contributions to specific and general cognitive ability differences, and how these differ from early childhood to old age. Special mention is also made of multivariate studies that examine the genetic correlation between intelligence test scores and their correlates such as processing speed, birth weight and brain size. After an overview of candidate gene associations with intelligence test scores, there is a discussion of whole-genome linkage and association studies, the first of which have only recently appeared.

Age Factors↗

[Language development disorders in childhood: nonverbal intelligence and language comprehension].

33 children with Specific Language Impairment (F 80, ICD 10) were randomly selected and their results regarding nonverbal intelligence, passive vocabulary and sentence comprehension were compared with data of 33 control children matched by age and sex. Although cognitive performance is average in both groups, significant differences regarding nonverbal intelligence are found. Whereas nonverbal intelligence is predictable from sentence comprehension to a high degree in den SLI-group, it is not predictable in the control group.

Austria↗

Does HOME add to the prediction of child intelligence over and above SES?

The most frequently used measure of the educational stimulation provided by the child's home environment is socioeconomic status (SES). Because SES is a global measure, researchers have developed measures that provide more detailed information. One of these is the Home Observation for Measurement of the Environment (HOME), (Caldwell & Bradley, 1984). Our research examined whether HOME adds to the predictability of child intelligence beyond that provided by SES. Subjects were 121 3-year-olds, Black and White, who were administered the fourth edition of the Stanford-Binet and the Peabody Picture Vocabulary Test-Revised. HOME and Hollingshead SES scores were obtained at age 2. HOME added to the predictability of intelligence over and above that provided by SES for the total group of children and for White children but not for Black children. The predictive utility of HOME also depended on the type of intelligence test being used.

Black or African American↗

Intelligence and left hemisphere disease. The role of aphasia, apraxia and size of lesion.

The Raven Progressive Matrices and four subtests of the Wechsler-Bellevue Performance Scale were given to 173 left hemisphere patients subdivided according to presence/absence, type (fluent/non-fluent) and severity (moderate/severe) of aphasia. Constructive and ideomotor apraxia scores and CT scan data of each subject entered the statistical analysis. Factors significant in producing a low score on Progressive Matrices and Wechsler-Bellevue were presence of aphasia and constructive apraxia. Site and size of lesion per se failed to account for the intelligence scores. The relationship between aphasia, apraxia, intelligence test scores, and CT scan data were discussed in an attempt to clarify the meaning of these low intelligence test scores in aphasics and to assess the underlying roles of the brain lesions in this deficit. It appears that there are a number of methodological difficulties complicating interpretation of the intellectual deficit based on the Progressive Matrices and Wechsler-Bellevue scores, since performance on these tests is adversely affected by both aphasia and apraxia.

Aphasia↗

Intelligence and information processing during a visual search task in children: an event-related potential study.

To investigate the differences in event-related potential parameters related to children's intelligence, we selected 15 individuals from an experimental class of intellectually gifted children and 13 intellectually average children as control to finish three types of visual search tasks (Chinese words, English letters and Arabic numbers). We recorded the electroencephalogram and calculated the peak latencies and amplitudes. Our results suggest comparatively increased P3 amplitudes and shorter P3 latencies in brighter individuals than in less intelligent individuals, but this expected neural efficiency effect interacted with task content. The differences were explained by a more spatially and temporally coordinated neural network for more intelligent children.

Brain Mapping↗

Fluctuating asymmetry and psychometric intelligence.

Little is known about the genetic nature of human psychometric intelligence (IQ), but it is widely assumed that IQ's heritability is at loci for intelligence per se. We present evidence consistent with a hypothesis that interindividual IQ differences are partly due to heritable vulnerabilities to environmental sources of developmental stress, an indirect genetic mechanism for the heritability of IQ. Using fluctuating asymmetry (FA) of the body (the asymmetry resulting from errors in the development of normally symmetrical bilateral traits under stressful conditions), we estimated the relative developmental instability of 112 undergraduates and administered to them Cattell's culture fair intelligence test (CFIT). A subsequent replication on 128 students was performed. In both samples, FA correlated negatively and significantly with CFIT scores. We propose two non-mutually exclusive physiological explanations for this correlation. First, external body FA may correlate negatively with the developmental integrity of the brain. Second, individual energy budget allocations and/or low metabolic efficiency in high-FA individuals may lower IQ scores. We review the data on IQ in light of our findings and conclude that improving developmental quality may increase average IQ in future generations.

Adolescent↗

The relationship between blood lead concentrations, intelligence and attainment in a school population: a pilot study.

One-hundred-and-sixty-six children whose blood lead levels had previously been determined were assessed on a battery of psychometric tests. Blood lead levels ranged from 7 to 33 micrograms/100 ml, and the group performed within the average range on all tests of attainment and intelligence. There were significant associations between blood lead levels and attainment scores on tests of reading, spelling and intelligence, but not on mathematics. These differences in performances largely remained after social class was partialled out. Partial correlation and multiple regression analyses suggest that while only a small proportion of the variance in intelligence is explained by blood lead levels, this relationship is independent of social class. Caution is necessary in interpreting these findings, in view of the crude measure of social factors available.

Achievement↗

Development of intelligence and neuropsychological impairment scales for the Washington Psychosocial Seizure Inventory.

The Washington Psychosocial Seizure Inventory (WPSI) was used to evaluate the relative extent of psychosocial problems in 379 adults with epilepsy, having differing levels of intelligence and neuropsychological impairment. In general, there were more psychosocial problems when abilities were decreased. Two new scales for the WPSI were developed, one of which provides an index of intelligence and the other an index of neuropsychological impairment. When groups of patients are considered, these scales correlate well with the Wechsler Adult Intelligence Scale and with the Neuropsychological Battery for Epilepsy, respectively, but less well when there is consideration of individual cases. The uses and limitations of the new scales in research and clinical contexts are discussed.

Adolescent↗

The effects of chronological age on the relationship of intelligence and academic achievement with extraversion and neuroticism.

This study examines the possibility that the relationships of intelligence and academic achievement with both extraversion and neuroticism may vary with chronological age. A sample of 741 students in the 15-19 age group worked through a battery of four tests, two of which were tests of intelligence and two tests of achievement in chemistry. The nature of the relationships between performance on these tests and measures of extraversion, neuroticism and chronological age were then expressed as multiple regression equations. The results whoed a consistently different pattern of significant relationships for both extraversion and neuroticism with the achievement tests on the one hand and with the intelligence tests on the other. Only the performance on the two achievement tests depended upon an interaction between extraversion and chronological age. There were no such interactions involving neuroticism and chronological age.

Achievement↗

Effect of genotype on changes in intelligence quotient after dietary relaxation in phenylketonuria and hyperphenylalaninaemia.

BACKGROUND: Associations between genotype and intellectual outcome in patients with phenylketonuria are complicated because intelligence is influenced by many variables, including environmental factors and other genetic determinants. Intellectual changes with age, both on and after relaxation of diet, vary within the patient population. This study aims to determine whether a significant association exists between genotype and change in intelligence after relaxation of diet. METHODS: 125 patients with hyperphenylalaninaemia and phenylketonuria whose diet was relaxed after 8 years of age. Verbal, performance, and full scale intelligence quotients at 8, 14, and 18 years were expressed as standard deviation scores (IQ-SDS), and genotype as predicted residual enzyme activity (PRA) of phenylalanine hydroxylase. RESULTS: IQ-SDS at 8, 14, and 18 years were significantly below normal; no association was found between PRA and IQ-SDS. Significant reductions in verbal and full scale IQ-SDS occurred between 8 and 14 years and 8 and 18 years. There was a significant association between PRA and the reduction in verbal, performance, and full scale IQ between these years. Multiple regression analysis of 18 year results, using 8 year results as covariates, supported the association between PRA and IQ-SDS; after adjustment for phenylalanine control, both up to and after the age of 8 years, the full scale IQ-SDS at 14 and 18 years was 0.15 higher for each 10% increase in PRA. CONCLUSIONS: Genotype might be useful in predicting the likelihood of intellectual change in patients with hyperphenylalaninaemia and phenylketonuria whose diet is relaxed after the age of 8 years.

Adolescent↗

Relationship between childhood infections and measured intelligence.

The possibility that some of the common childhood infections lead to unrecognized impairments of neurological function was examined in 43 820 Birmingham children whose intelligence was assessed in the 11-plus examination. Mean verbal reasoning scores were lower for children who had had measles or pertussis than for those who had had neither of these diseases. However, since attack rates and measured intelligence are related inversely to social class, the lower scores of children with measles and pertussis may be due to class differences which are not eliminated completely by standardization for maternal age and birth order. Mean scores were a little higher for children who had had rubella than for those who had not, and it is suggested that this difference may be due to more frequent reporting of the disease by the more intelligent mothers.

Birth Order↗