Apolipoprotein E Gene Variability and Cognitive Functions at Age 79: A Follow-Up of the Scottish Mental Survey of 1932.

Apolipoprotein E (APOE) genotype is a possible influence on nonpathological cognitive aging. The authors studied 462 community-dwelling, 79-year-old people born in 1921, whose childhood IQ had been assessed in the Scottish Mental Survey of 1932 (Scottish Council for Research in Education, 1933). Adjusting for sex, childhood IQ, and self-reported illnesses, the authors found that those with an APOE e4 allele had significantly lower Wechsler Logical Memory (D. Wechsler, 1987) scores than those without an e4 allele. Those people with APOE s2/e3 genotypes had significantly higher Wechsler Logical Memory scores than e3/s3, who were significantly higher than e3/e4. Neither nonverbal reasoning nor verbal fluency were affected. In this sample, APOE genotype contributed to verbal memory in old age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological and physical health at age 70 in the Lothian Birth Cohort 1936: Links with early life IQ, SES, and current cognitive function and neighborhood environment.

Objective: Researchers in many fields are interested in the robust observation that higher socioeconomic status (SES) is associated with better mental and physical health. Prominent explanations for the association involve effects of stress due to relative material and social adversity in lower socioeconomic environments, but early-life intelligence may also contribute directly to both later-life socioeconomic status and health. Here, we evaluated the effects of early-life IQ on mental and physical health outcomes at age 70, in the context of effects of SES. Design: The Lothian Birth Cohort of 1936 took part in the Scottish Mental Survey of 1947, providing a measure of IQ at age 11. They have been extensively surveyed at age 70. Main Outcome Measures: Body mass index, constraints on daily life activities, hospital anxiety and depression, number of diseases, level of physical activity, weekly units of alcohol consumption, and pack-years of smoking. Results and Conclusion: SES had apparently direct effects on most outcomes, but age 11 IQ was also involved in several, either directly or because it contributed to SES. Several interactions helped to integrate these associations. High age-11 IQ tended to buffer effects of adverse environments on physical and mental problems in old age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stability and change in intelligence from age 11 to ages 70, 79, and 87: The Lothian Birth Cohorts of 1921 and 1936.

Investigating the predictors of age-related cognitive change is a research priority. However, it is first necessary to discover the long-term stability of measures of cognitive ability because prior cognitive ability level might contribute to the amount of cognitive change experienced within old age. These two issues were examined in the Lothian Birth Cohorts of 1921 and 1936. Cognitive ability data were available from age 11 years when the participants completed the Moray House Test No. 12 (MHT). The Lothian Birth Cohort 1936 (LBC1936) completed the MHT a second time at age 70. The Lothian Birth Cohort 1921 (LBC1921) completed the MHT at ages 79 and 87. We examined cognitive stability and change from childhood to old age in both cohorts, and within old age in the LBC1921. Raw stability coefficients for the MHT from 11–70, 11–79, and 11–87 years were .67, .66, and .51, respectively; and larger when corrected for range restriction in the samples. Therefore, minimum estimates of the variance in later-life MHT accounted for by childhood performance on the same test ranged from 26–44%. This study also examined, in the LBC1921, whether MHT score at age 11 influenced the amount of change in MHT between ages 79 and 87. It did not. Higher intelligence from early life was apparently protective of intelligence in old age due to the stability of cognitive function across the lifespan, rather than because it slowed the decline experienced in later life. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Children's cognitive ability from 4 to 9 years old as a function of prenatal cocaine exposure, environmental risk, and maternal verbal intelligence.

This study examined the effects of prenatal cocaine exposure, environmental risk, and maternal verbal intelligence on children's cognitive ability. Gender and age were examined as moderators of potential cocaine exposure effects. The Stanford-Binet IV intelligence test was administered to 231 children (91 cocaine exposed, 140 unexposed) at ages 4, 6, and 9 years. Neonatal medical risk and other prenatal exposures (alcohol, cigarettes, and marijuana) were also examined for their unique effects on child IQ. Mixed models analysis indicated that prenatal cocaine exposure interacted with gender, as cocaine-exposed boys had lower composite IQ scores. Age at assessment did not moderate this relation, indicating that cocaine-exposed boys had lower IQs across this age period. A stimulating home environment and high maternal verbal IQ also predicted higher composite IQ scores. Cocaine-exposed boys had lower scores on the Abstract/Visual Reasoning subscale, with trends for lower scores on the Short-Term Memory and Verbal Reasoning subscales, as exposure effects were observed across domains. The findings indicate that cocaine exposure continues to place children at risk for mild cognitive deficits into preadolescence. Possible mechanisms for the Exposure × Gender interaction are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are processing speed tasks biomarkers of cognitive aging?

We examined the association between 5 processing speed measures and general cognitive ability in a large (>900) sample of relatively healthy men and women at age 70. The processing speed tests were the Wechsler Digit Symbol-Coding and Symbol Search, simple reaction time, 4-choice reaction time, and inspection time. To inquire whether the processing speed tasks might be biomarkers of cognitive aging, we examined the attenuations in their associations with general cognitive ability after adjusting for cognitive ability measured almost 60 years earlier. With the exception of inspection time, the attenuations were substantial. Inspection time was the only processing speed measure—all of which were measured at age 70—whose correlation with cognitive ability at age 70 was significantly greater than the correlation with cognitive ability at age 11. In old age, individual differences in most commonly used measures of processing speed are largely dependent on childhood cognitive ability. For all processing speed tasks, a little variance is left that appears to be related to aging differences. Inspection time, the marker that was least dependent on childhood intelligence, should be considered further as one biomarker of cognitive aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulation seeking and intelligence: A prospective longitudinal study.

The prediction that high stimulation seeking 3-yr-olds would have higher IQs by 11 yrs old was tested in 1,795 children on whom behavioral measures of stimulation seeking were taken at 3 yrs, together with cognitive ability at 11 yrs. High 3-yr-old stimulation seekers scored 12 points higher on total IQ at age 11 compared with low stimulation seekers and also had superior scholastic and reading ability. Results replicated across independent samples and were found for all gender and ethnic groups. Effect sizes for the relationship between age 3 stimulation seeking and age 11 IQ ranged from 0.52 to 0.87. Findings appear to be the first to show a prospective link between stimulation seeking and intelligence. It is hypothesized that young stimulation seekers create for themselves an enriched environment that stimulates cognitive development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Association between sleep duration and intelligence scores in healthy children.

We examined the association between sleep behavior and cognitive functioning in 60 healthy children between 7 and 11 years of age under nonexperimental conditions. Intellectual abilities were assessed by the Wechsler Intelligence Scale for Children (4th edition) and sleep variables by questionnaires, actigraphy, and sleep diaries. Correlation analysis revealed a negative association between sleep duration on weekends and measures of intelligence (full-scale IQ, r = ?.29; fluid IQ, r = ?.36). The regression coefficient for sleep duration on weekends was ?6.11 (SE = 2.09), indicating an increase of 6.11 points on fluid IQ scores for each hour of shorter sleep duration. Attention measures did not correlate with cognitive or sleep variables. Daytime sleepiness as a potential moderator of the relationship between sleep duration and cognitive performance was not related to cognitive or sleep variables. We conclude that children with higher daytime cognitive efficiency (reflected by higher intelligence scores) show increased nighttime efficiency (reflected by shorter sleep duration). In the light of the neural efficiency hypothesis, the current results argue for an extension of the original theory—referring not only to daytime but also to nighttime behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cerebral white matter abnormalities and lifetime cognitive change: A 67-year follow-up of the Scottish Mental Survey of 1932.

Cerebral white matter abnormalities relate to cognitive functioning in elders. We examine whether this association is (a) independent of mental ability in youth and (b) related to general and/or specific mental abilities. We retested 83 participants of the Scottish Mental Survey of 1932 on a battery of mental tests. Their brains were scanned by magnetic resonance imaging. Three independent ratings (Fazekas) were made of periventricular, and subcortical and deep white matter abnormalities. Structural equation models showed that, irrespective of brain location, white matter abnormalities contributed about 14% of cognitive function variance in old age. Some of this effect might be due to hypertension. This contribution is independent of mental function in early life and is associated with general cognitive ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the growth of intelligence.

Data from the Berkeley Growth Study pertaining to the development of intelligence as measured by tests, and some related material, are reviewed. The concept of IQ constancy, prediction of later intelligence scores from infancy scores, and problems encountered in constructing curves of growth in intelligence, are some of the topics discussed. An age curve of intelligence from birth to 50 years, based on data of 3 studies, is proposed and graphically represented. "This curve is offered as an alternative to previously published age-curves of intelligence." It is hoped that further research will refine, modify, and extend it into a more complete and accurate representation of intellectual changes over the entire span of life. 31 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

White matter lesions account for all age-related declines in speed but not in intelligence.

MRI scans measured white matter lesion prevalence (WMLP) in 65 people ages 65-84 years who also took 17 cognitive tests: 3 tests of general fluid intelligence, 3 of vocabulary, 2 of episodic and 3 of working memory, 2 of processing speed, and 4 of frontal and executive function. Entry of age with WMLP into regression equations as predictors of test scores showed that inferences about the functional relationships between markers of brain aging and cognitive impairments are seriously misleading if they are based on simple correlations alone. A new finding that WMLP accounts for all of the age-related variance between individuals in tests of speed and executive ability but for none of the age-related variance in intelligence revises current hypotheses that gross brain changes affect general fluid intelligence and other mental abilities solely through their effects on information-processing speed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do clever old people have earlier and richer first memories?

In a study of 377 people, from 54 to 83 years old, it was shown that the age of earliest memories was unrelated to current age but was related to intelligence. People with high IQ test scores remembered first and second memories at an earlier age than did those with lower IQ test scores. Intervals between first and second memories were briefer for those with high scores. The content of early memories was unrelated to age or intelligence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alcohol intake and cognitive abilities in old age: The Lothian Birth Cohort 1936 study.

Objective: Moderate alcohol consumption has been associated with better cognitive performance in late adulthood, possibly by improving vascular health. Few studies have examined the potentially confounding roles of prior cognitive ability and social class in this relationship. Method: Participants were 922 healthy adults about 70 years old in the Lothian Birth Cohort 1936 study, for whom there are IQ data from age 11. Alcohol consumption was obtained by self-report questionnaire. Cognitive outcome measures included general cognitive ability, speed of information processing, memory, and verbal ability. Results: Moderate to substantial drinking (>2 units/day) was associated with better performance on cognitive tests than low-level drinking (≤2 units/day) or nondrinking in men and women. After adjusting for childhood IQ and adult social class, most of these associations were removed or substantially attenuated. After full adjustment, a small, positive association remained between overall alcohol intake and memory (women and men) and verbal ability (women only). Women's overall alcohol intake was derived almost exclusively from wine. In men, effects differed according to beverage type: wine and sherry–port consumption was associated with better verbal ability, but beer was associated with a poorer verbal ability and spirits intake was associated with better memory. Conclusions: Prior intelligence and socioeconomic status influence both amount and type of alcohol intake and may partly explain the link between alcohol intake and improved cognitive performance at age 70. Alcohol consumption was found to make a small, independent contribution to memory performance and verbal ability, but these findings' clinical significance is uncertain. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Is body mass index in old age related to cognitive abilities? The Lothian Birth Cohort 1936 Study.

We tested the hypothesis that the previously reported association between a higher body mass index (BMI) and poorer cognition in later adulthood is an artifact of confounding by previous cognitive ability and socioeconomic status. Participants were 1,079 adults aged about 70 years in the Lothian Birth Cohort 1936 Study, on whom there are IQ data from age 11. Cognitive outcome measures included: IQ at age 70 using the same test that was administered at age 11; composite measures of general cognitive ability (g factor), speed of information processing, and memory; and two tests of verbal ability. People classified as overweight or obese in later adulthood had significantly lower scores on tests of childhood IQ, age 70 IQ, g factor, and verbal ability. There was no significant association with processing speed or memory performance. After adjusting for childhood IQ and social class in general linear models, associations with age 70 IQ and g factor were nonsignificant or attenuated. However, throughout the models, there was a persistent (inverse) relationship between BMI and performance on the National Adult Reading Test (NART) and Wechsler Test of Adult Reading (WTAR), which remained significant after full adjustment for all sociodemographic and health covariates (for the NART, p = .025; for the WTAR, p = .011). The findings suggest that the previously reported BMI–cognition associations in later adulthood could be largely accounted for by prior ability and socioeconomic status, and by the possible influence of these factors on the adoption of health behaviors in adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive ability at age 11 and 70 years, information processing speed, and APOE variation: The Lothian Birth Cohort 1936 study.

The e4 allele of the apolipoprotein E (APOE) gene confers risk of Alzheimer's disease and, in some studies, relates to cognitive ability and decline in older people without Alzheimer's disease. Its relationship with processing speed, a contributor to cognitive decline with age, is largely unknown. This study tests the association of APOE with cognition and speed, with and without covarying childhood mental ability. The 1,013 participants were tested on cognitive ability at age 11 as part of the Scottish Mental Survey of 1947 and, at age 70, were tested on reasoning, working memory, information processing speed, and executive function. The results showed that APOE was associated with the general cognitive factor, 2 nonverbal tests, and choice reaction time (RT) variability; as expected, the e4 allele was the risk allele. RT measures and a general speed factor were nonlinearly related to APOE when factoring childhood ability (p     

Losses in gross brain volume and cerebral blood flow account for age-related differences in speed but not in fluid intelligence.

Age-related gross head size; adjusted age-related change in brain volume and carotid and basilar blood flow; as well as scores on 3 tests of fluid intelligence (gf), 2 tests of information-processing speed, 2 memory tests, and 3 tests of executive function were obtained from 69 volunteers aged from 62 to 84 years. Brain volume negatively predicted scores on all 10 cognitive tasks, accounting for up to 78% of age-related variance in scores on the speed tasks and on 1 executive task. Cerebral blood flow (CBF) negatively predicted scores on 8 cognitive tasks, accounting for up to 36% of age-related variance in speed scores. However, neither brain volume nor CBF accounted for significant age-related variance between individuals on any of 3 gf tests. We conclude that speed, but not gf, is an exceptionally sensitive behavioral index of the progress of gross brain changes that affect cognition in old age and that speed and gf do not reflect integrity of the same functional systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chronic inhibition of NO synthase enhances the production of prostacyclin in coronary arteries through upregulation of the cyclooxygenase type 1 isoform

The relationships of medical, developmental, social, and familial variables to intellectual performances (IQ scores) were assessed in a sample of 242 adult patients with intractable lateralized temporal lobe epilepsy. Lower IQ scores were associated with low patient and parent education. In addition to the significant contributions of nonneurological social and familial factors to IQ, early age at onset of regular seizures and presence of primary neurological dysfunction in the left cerebral hemisphere were also both independently related to lower IQ. The obtained results suggest that the occurrence of regular seizures during a critical period in early childhood neural maturation poses the greatest risk to cognitive development in the epilepsy population. Total duration of seizures, history of severe convulsive episodes, and the occurrence of another nonepileptic neurological problem in early childhood do not contribute significantly to delayed cognitive development.     

Use of IQ-Adjusted Norms to Predict Progressive Cognitive Decline in Highly Intelligent Older Individuals.

Identifying high-functioning older individuals in preclinical phases of Alzheimer's disease (AD) may require more sensitive methods than the standard approach. The authors explored the utility of adjusting for premorbid intelligence to predict progressive cognitive decline or Mild Cognitive Impairment (MCI) in 42 highly intelligent older individuals. When scores were adjusted for baseline IQ, 9 participants had executive impairments, 11 had memory impairments, and 22 scored in the normal range. None were impaired according to standard age norms. Three and a half years later, 9 participants with IQ-adjusted memory impairment declined in naming, visuospatial functioning, and memory; 6 convened to MCI. Three participants with normal memory declined. Implications for using IQ-adjusted norms to predict preclinical AD are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An exploratory analysis of American Indian children's cultural engagement, fluid cognitive skills, and standardized verbal IQ scores.

This exploratory cross-sectional study examined fluid cognitive skills and standardized verbal IQ scores in relation to cultural engagement amongst Tohono O'odham children (N = 99; ages 7 to 12 years). Guardians with higher socioeconomic status engaged their children in more cultural activities, and participation in more cultural activities contributed to higher standardized verbal IQ scores. Mean cognitive skill scores varied as a function of age and Tohono O'odham language knowledge. Children who understood and/or spoke Tohono O'odham started out with lower average scores than did children with no language knowledge, but mean scores generally increased in the older age groups such that they were equal to or higher than those of nonspeakers by age 9. Children with higher fluid cognitive skill scores had higher standardized verbal IQ scores than did children with lower scores. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Declining blood lead levels and changes in cognitive function during childhood: the Port Pirie Cohort Study

CONTEXT: Many studies have found a significant inverse association between early exposure to environmental lead and cognitive function in childhood. Whether these effects are reversible when exposure is reduced is not clear. OBJECTIVE: To assess the reversibility of the apparent effects of lead on cognitive abilities in early childhood by testing whether declines in blood lead concentrations beyond the age of 2 years are associated with improvements in cognition. SETTING: Urban and rural communities surrounding a large lead smelter in Port Pirie, South Australia. PARTICIPANTS: A total of 375 children followed up from birth to the age of 11 to 13 years. DESIGN: Long-term prospective cohort study. MAIN OUTCOME MEASURES: The Bayley Mental Development Index at age 2 years, the McCarthy General Cognitive Index at age 4 years, and IQs from the Wechsler Intelligence Scale (revised version) at ages 7 and 11 to 13 years. RESULTS: Mean blood lead concentrations in the children decreased from 1.02 pmol/L (21 .2 microg/dL) at age 2 years to 0.38 micromol/L (7.9 microg/dL) at age 1 1 to 13 years, but cognitive scores in children whose blood lead concentration declined most were generally not improved relative to the scores of children whose blood lead levels declined least. Changes in IQ and declines in blood lead levels that occurred between the ages of 7 and 11 to 13 years (r= 0.12, P= .09) suggested slightly better cognition among children whose blood lead levels declined most. CONCLUSION: The cognitive deficits associated with exposure to environmental lead in early childhood appear to be only partially reversed by a subsequent decline in blood lead level.     

Cognitive style and defenses: A longitudinal study of intellectualization and field independence.

Investigated the long-range stability of the defense style of intellectualization (assessed by ratings of Rorschach protocols), and its relation to an analytic field-independent cognitive style (assessed by scores on the Rod and Frame, RFT, test). 28 male Ss had been administered the Rorschach and the RFT at age 14, 17, and 24 (1/2 of the sample was tested at age 10) and the Wechsler-Bellevue at age 17, as part of a broader longitudinal study. Results indicate that individual differences in Rorschach ratings of intellectualization tend to remain stable from childhood to young adulthood. Intellectualization ratings were also positively related to field independence and IQ. (PsycINFO Database Record (c) 2010 APA, all rights reserved)