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65-486: Major cognitive ageing findings of the studies have concerned the stability of intelligence from childhood to old age, the influence of genetics on cognitive function and decline, and the role of the brain's white matter integrity in successful cognitive ageing. The studies have also been at the vanguard of the field of cognitive epidemiology , which explores how intelligence relates to physical and mental health outcomes. The Lothian Birth Cohort studies are led by Ian Deary ,

130-484: A SNP allele that is common in one geographical or ethnic group may be much rarer in another. However, this pattern of variation is relatively rare; in a global sample of 67.3 million SNPs, the Human Genome Diversity Project "found no such private variants that are fixed in a given continent or major region. The highest frequencies are reached by a few tens of variants present at >70% (and

195-542: A common consensus. The rs### standard is that which has been adopted by dbSNP and uses the prefix "rs", for "reference SNP", followed by a unique and arbitrary number. SNPs are frequently referred to by their dbSNP rs number, as in the examples above. The Human Genome Variation Society (HGVS) uses a standard which conveys more information about the SNP. Examples are: SNPs can be easily assayed due to only containing two possible alleles and three possible genotypes involving

260-420: A diverse range of influences on cognitive ageing, including the effects of economic, medical, psychological and social variables. For Wave 2, a specific focus was placed on finding how the white matter of the brain becomes damaged and what relationship white matter damage has with age-related cognitive decline. As well as being used to research the topics of major findings outlined below, LBC data has been used in

325-666: A diverse range of other investigations. For example, LBC1921 participants served as a control group in a study that validated of the use of the National Adult Reading Test as a measure of premorbid cognition in individuals with dementia . LBC1921 data has also been used to find that facial symmetry , as measured by fluctuating asymmetry , is linked to successful cognitive ageing. Data from both Lothian Birth Cohorts has been used to study changes over time in social class mobility and to find strong rank-order stability of personality traits in old age. Studies of

390-442: A factor in the severity of obstructive sleep apnea . The study of white matter has been advanced with the neuroimaging technique called diffusion tensor imaging where magnetic resonance imaging (MRI) brain scanners are used. As of 2007, more than 700 publications have been published on the subject. A 2009 paper by Jan Scholz and colleagues used diffusion tensor imaging (DTI) to demonstrate changes in white matter volume as

455-777: A few thousands at >50%) in Africa, the Americas, and Oceania. By contrast, the highest frequency variants private to Europe, East Asia, the Middle East, or Central and South Asia reach just 10 to 30%." Within a population, SNPs can be assigned a minor allele frequency —the lowest allele frequency at a locus that is observed in a particular population. This is simply the lesser of the two allele frequencies for single-nucleotide polymorphisms. With this knowledge scientists have developed new methods in analyzing population structures in less studied species. By using pooling techniques

520-409: A good probability of a match. This can additionally be applied to increase the accuracy of facial reconstructions by providing information that may otherwise be unknown, and this information can be used to help identify suspects even without a STR DNA profile match. Some cons to using SNPs versus STRs is that SNPs yield less information than STRs, and therefore more SNPs are needed for analysis before

585-400: A man at 80 years of age has 97,200 km and a woman 82,000 km. Most of this reduction is due to the loss of thinner fibers. However, this reduction may correlate with men having larger brains than women and with brain size reducing with age. White matter is the tissue through which messages pass between different areas of grey matter within the central nervous system. The white matter

650-545: A minority of individuals. The two possible nucleotide variations of this SNP – G or A – are called alleles . SNPs can help explain differences in susceptibility to a wide range of diseases across a population. For example, a common SNP in the CFH gene is associated with increased risk of age-related macular degeneration. Differences in the severity of an illness or response to treatments may also be manifestations of genetic variations caused by SNPs. For example, two common SNPs in

715-528: A powerful tool to map genomic regions or genes that are involved in disease pathogenesis. Recently, preliminary results reported SNPs as important components of the epigenetic program in organisms. Moreover, cosmopolitan studies in European and South Asiatic populations have revealed the influence of SNPs in the methylation of specific CpG sites. In addition, meQTL enrichment analysis using GWAS database, demonstrated that those associations are important toward

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780-751: A profile of a suspect is able to be created. Additionally, SNPs heavily rely on the presence of a database for comparative analysis of samples. However, in instances with degraded or small volume samples, SNP techniques are an excellent alternative to STR methods. SNPs (as opposed to STRs) have an abundance of potential markers, can be fully automated, and a possible reduction of required fragment length to less than 100bp.[26] Pharmacogenetics focuses on identifying genetic variations including SNPs associated with differential responses to treatment. Many drug metabolizing enzymes, drug targets, or target pathways can be influenced by SNPs. The SNPs involved in drug metabolizing enzyme activities can change drug pharmacokinetics, while

845-407: A result of learning a new motor task (e.g. juggling). The study is important as the first paper to correlate motor learning with white matter changes. Previously, many researchers had considered this type of learning to be exclusively mediated by dendrites, which are not present in white matter. The authors suggest that electrical activity in axons may regulate myelination in axons. Or, gross changes in

910-449: A similar manner as the cerebrum, with a superficial mantle of cerebellar cortex, deep cerebellar white matter (called the " arbor vitae ") and aggregates of grey matter surrounded by deep cerebellar white matter ( dentate nucleus , globose nucleus , emboliform nucleus , and fastigial nucleus ). The fluid-filled cerebral ventricles (lateral ventricles, third ventricle , cerebral aqueduct , fourth ventricle ) are also located deep within

975-802: A variety of sources, including but not limited to the Biotechnology and Biological Sciences Research Council , the Medical Research Council , the Scottish Government's Chief Scientist Office , Age UK and Research into Ageing . LBC1921 participant recruitment began in 1999. Participants were mainly recruited by tracing SMS1932 participants in the Edinburgh area using the Community Health Index (CHI), and then asking general practitioners to contact

1040-410: Is a germline substitution of a single nucleotide at a specific position in the genome . Although certain definitions require the substitution to be present in a sufficiently large fraction of the population (e.g. 1% or more), many publications do not apply such a frequency threshold. For example, a G nucleotide present at a specific location in a reference genome may be replaced by an A in

1105-426: Is a hypothesis driven approach. Since only a limited number of SNPs are tested, a relatively small sample size is sufficient to detect the association. Candidate gene association approach is also commonly used to confirm findings from GWAS in independent samples. Genome-wide SNP data can be used for homozygosity mapping. Homozygosity mapping is a method used to identify homozygous autosomal recessive loci, which can be

1170-625: Is a possibility in combining the advantages of SNPs with micro satellite markers. However, there are information lost in the process such as linkage disequilibrium and zygosity information. Variations in the DNA sequences of humans can affect how humans develop diseases and respond to pathogens , chemicals , drugs , vaccines , and other agents. SNPs are also critical for personalized medicine . Examples include biomedical research, forensics, pharmacogenetics, and disease causation, as outlined below. One of main contributions of SNPs in clinical research

1235-479: Is continuous throughout one's lifetime due to neuroplasticity , and is a contributing factor rather than determinant factor of certain functional deficits due to compensating effects in other brain regions. The integrity of white matter declines due to aging. Nonetheless, regular aerobic exercise appears to either postpone the aging effect or in turn enhance the white matter integrity in the long run. Changes in white matter volume due to inflammation or injury may be

1300-523: Is genome-wide association study (GWAS). Genome-wide genetic data can be generated by multiple technologies, including SNP array and whole genome sequencing. GWAS has been commonly used in identifying SNPs associated with diseases or clinical phenotypes or traits. Since GWAS is a genome-wide assessment, a large sample site is required to obtain sufficient statistical power to detect all possible associations. Some SNPs have relatively small effect on diseases or clinical phenotypes or traits. To estimate study power,

1365-551: Is implied if a contemporaneous association in old age is attenuated or eliminated after childhood intelligence is controlled for, which would suggest that the association existed partially or wholly due to the effects of earlier intelligence. Reverse causation has been separately reported for relationships in the LBC1936 between intelligence and each of caffeine consumption, body mass index , alcohol consumption and inflammation . White matter White matter refers to areas of

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1430-679: Is not homogenous; SNPs occur in non-coding regions more frequently than in coding regions or, in general, where natural selection is acting and "fixing" the allele (eliminating other variants) of the SNP that constitutes the most favorable genetic adaptation. Other factors, like genetic recombination and mutation rate, can also determine SNP density. SNP density can be predicted by the presence of microsatellites : AT microsatellites in particular are potent predictors of SNP density, with long (AT)(n) repeat tracts tending to be found in regions of significantly reduced SNP density and low GC content . There are variations between human populations, so

1495-534: Is related to old age intelligence, it has been reported to be unrelated to change in intelligence between ages 79 and 87 in the LBC1921. This finding suggested that childhood intelligence is related to old age intelligence because of the stability of intelligence rather than because it protects against decline in old age. The LBC1936 also re-sat the Moray House Test in old age. In this larger cohort, there

1560-463: Is the most common of the inflammatory demyelinating diseases of the central nervous system which affect white matter. In MS lesions, the myelin sheath around the axons is deteriorated by inflammation . Alcohol use disorders are associated with a decrease in white matter volume. Amyloid plaques in white matter may be associated with Alzheimer's disease and other neurodegenerative diseases . Other changes that commonly occur with age include

1625-433: Is white because of the fatty substance (myelin) that surrounds the nerve fibers (axons). This myelin is found in almost all long nerve fibers, and acts as an electrical insulation. This is important because it allows the messages to pass quickly from place to place. Unlike grey matter, which peaks in development in a person's twenties, the white matter continues to develop, and peaks in middle age. Multiple sclerosis (MS)

1690-797: The APOE gene, rs429358 and rs7412, lead to three major APO-E alleles with different associated risks for development of Alzheimer's disease and age at onset of the disease. Single nucleotide substitutions with an allele frequency of less than 1% are sometimes called single-nucleotide variants (SNVs) . "Variant" may also be used as a general term for any single nucleotide change in a DNA sequence, encompassing both common SNPs and rare mutations , whether germline or somatic . The term SNV has therefore been used to refer to point mutations found in cancer cells. DNA variants must also commonly be taken into consideration in molecular diagnostics applications such as designing PCR primers to detect viruses, in which

1755-507: The HMGN1 gene, 13 SNPs and four candidate genes, including APOE , were statistically significant predictors of general cognitive function. Data from both cohorts was also used, in combination with other data, to establish that intelligence is highly polygenic . In addition, LBC1921 and LBC1936 data was used in calculating the first estimate of the genetic correlation between childhood and old age intelligence in unrelated individuals, which

1820-587: The APOE E4 allele's association with worse cognitive decline and function. A GWA study of longitudinal cohorts, including the LBC1921 and the LBC1936, found that the APOE E4 allele was associated with deleterious cognitive change. Furthermore, a 2015 meta-analysis of GWA studies in 31 cohorts, including the two Lothian Birth Cohorts, found that the APOE gene as well as SNPs on the APOE / TOMM40 genomic region were associated with general cognitive ability. Altogether,

1885-402: The brain to each other, and carry nerve impulses between neurons. Myelin acts as an insulator, which allows electrical signals to jump , rather than coursing through the axon, increasing the speed of transmission of all nerve signals. The total number of long range fibers within a cerebral hemisphere is 2% of the total number of cortico-cortical fibers (across cortical areas) and is roughly

1950-406: The central nervous system (CNS) that are mainly made up of myelinated axons , also called tracts . Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distribution of action potentials , acting as a relay and coordinating communication between different brain regions. White matter is named for its relatively light appearance resulting from

2015-559: The intergenic regions (regions between genes). SNPs within a coding sequence do not necessarily change the amino acid sequence of the protein that is produced, due to degeneracy of the genetic code . SNPs in the coding region are of two types: synonymous SNPs and nonsynonymous SNPs. Synonymous SNPs do not affect the protein sequence, while nonsynonymous SNPs change the amino acid sequence of protein. SNPs that are not in protein-coding regions may still affect gene splicing , transcription factor binding, messenger RNA degradation, or

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2080-406: The lipid content of myelin . However, the tissue of the freshly cut brain appears pinkish-white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries . Its white color in prepared specimens is due to its usual preservation in formaldehyde . White matter is composed of bundles, which connect various grey matter areas (the locations of nerve cell bodies) of

2145-546: The splenium of the corpus callosum has been found to be a marker of healthy cognitive ageing. Lower white matter hyperintensity load has also been considered a sign of successful cognitive ageing, because it was associated with higher general cognitive ability and faster processing speed at age 73 after age 11 intelligence was controlled for . Additionally, white matter integrity in some brain areas has been found to be weaker in APOE E4 allele carriers, and weaker white matter integrity has been shown to partially mediate some of

2210-673: The LBC1921 have provided the longest-term estimates of the stability of intelligence. They have found that intelligence in childhood is strongly correlated with intelligence in old age, and that this correlation exists because intelligence is highly stable trait, rather than because childhood intelligence is linked to rates of cognitive change during adulthood. The LBC1921 took the Moray House Test at ages 11, 79, 87 and 90, and results at all four sittings were strongly correlated. The raw correlations between test scores at age 11 and at ages 79, 87 and 90 were .66, .51 and .55 respectively, and they rose to .73, .61 and .67 respectively after correction for

2275-502: The SNPs involved in drug target or its pathway can change drug pharmacodynamics. Therefore, SNPs are potential genetic markers that can be used to predict drug exposure or effectiveness of the treatment. Genome-wide pharmacogenetic study is called pharmacogenomics . Pharmacogenetics and pharmacogenomics are important in the development of precision medicine, especially for life-threatening diseases such as cancers. Only small amount of SNPs in

2340-468: The SNPs with relatively small effect on diseases. For common and complex diseases, such as type-2 diabetes, rheumatoid arthritis, and Alzheimer's disease, multiple genetic factors are involved in disease etiology. In addition, gene-gene interaction and gene-environment interaction also play an important role in disease initiation and progression. As there are for genes, bioinformatics databases exist for SNPs. The International SNP Map working group mapped

2405-792: The Scottish Mental Surveys, the Aberdeen Birth Cohorts of 1921 and 1936, began in 1997 and 1999 respectively. A core aim of the LBC studies is to explore causes of different cognitive ageing outcomes. They have also been used to facilitate a variety of psychosocial, medical and genetic investigations. Each wave of data collection typically includes: cognitive tests; socio-demographic information; health behaviours and health status; fitness measures; and physical measures. Metabolic and inflammatory biomarkers have also been taken in both cohorts. The studies have been funded by

2470-525: The allele is a risk factor for cognitive decline. Later LBC1921 research found that possession of the E4 allele was associated with greater decline in abstract reasoning and verbal memory, but not verbal fluency, between age 79 and age 87. Additionally, in the LBC1936, the E4 allele has been associated with worse general cognitive ability at age 70, as well as with worse performance on some specific cognitive tests. Genome-wide association (GWA) studies have confirmed

2535-573: The brain is grey matter (actually pinkish tan due to blood capillaries), which is composed of neurons . The substantia nigra is a third colored component found in the brain that appears darker due to higher levels of melanin in dopaminergic neurons than its nearby areas. Note that white matter can sometimes appear darker than grey matter on a microscope slide because of the type of stain used. Cerebral and spinal white matter do not contain dendrites , neural cell bodies , or shorter axons, which can only be found in grey matter. White matter forms

2600-399: The bulk of the deep parts of the brain and the superficial parts of the spinal cord . Aggregates of grey matter such as the basal ganglia ( caudate nucleus , putamen , globus pallidus , substantia nigra , subthalamic nucleus , nucleus accumbens ) and brainstem nuclei ( red nucleus , cranial nerve nuclei) are spread within the cerebral white matter. The cerebellum is structured in

2665-436: The cerebral white matter. One small study found that men have more white matter than women both in volume and in length of myelinated axons, and that volume and length reduced with age. (This study only included 36 participants. ) At the age of 20, the total length of myelinated fibers in men is 176,000 km while that of a woman is 149,000 km. There is a decline in total length with age of about 10% each decade such that

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2730-410: The cost of the analysis is significantly lowered. These techniques are based on sequencing a population in a pooled sample instead of sequencing every individual within the population by itself. With new bioinformatics tools there is a possibility of investigating population structure, gene flow and gene migration by observing the allele frequencies within the entire population. With these protocols there

2795-955: The development of leukoaraiosis , which is a rarefaction of the white matter that can be correlated with a variety of conditions, including loss of myelin pallor, axonal loss, and diminished restrictive function of the blood–brain barrier . There is also evidence that substance abuse may damage white matter microstructure, though prolonged abstinence may in certain cases reverse such white matter changes. White matter lesions on magnetic resonance imaging are linked to several adverse outcomes, such as cognitive impairment and depression . White matter hyperintensities are often found in patients with vascular dementia , particularly with small vessel/subcortical subtypes of vascular dementia. Smaller volumes (in terms of group averages) of white matter might be associated with larger deficits in attention , declarative memory , executive functions , intelligence , and academic achievement . However, volume change

2860-401: The diameter or packing density of the axon might cause the change. A more recent DTI study by Sampaio-Baptista and colleagues reported changes in white matter with motor learning along with increases in myelination. Single-nucleotide polymorphisms In genetics and bioinformatics , a single-nucleotide polymorphism ( SNP / s n ɪ p / ; plural SNPs / s n ɪ p s / )

2925-649: The director of the Centre for Cognitive Ageing and Cognitive Epidemiology at the University of Edinburgh . The Lothian Birth Cohort (LBC) studies of 1921 (LBC1921) and 1936 (LBC1936) are follow-up studies of, respectively, the Scottish Mental Surveys (SMSs) of 1932 (SMS1932) and 1947 (SMS1947). The Scottish Mental Surveys, which were undertaken by the Scottish Council for Research in Education (SCRE), are

2990-533: The entire distribution of intelligence in Scottish pupils. It was conducted on 1 June 1932, and tested the intelligence of almost all of Scotland's 1921-born population, 87,498 children in all. The SMS1947 was commissioned to test the theory that average intelligence in the United Kingdom was lower in the new generation due to a negative correlation between family size and the intelligence of children. It

3055-483: The genetic model for disease needs to be considered, such as dominant, recessive, or additive effects. Due to genetic heterogeneity, GWAS analysis must be adjusted for race. Candidate gene association study is commonly used in genetic study before the invention of high throughput genotyping or sequencing technologies. Candidate gene association study is to investigate limited number of pre-specified SNPs for association with diseases or clinical phenotypes or traits. So this

3120-412: The harmful effects of the E4 allele on cognitive change. In the LBC1921, smoking was linked to greater cognitive decline at age 80. The mean IQ of current smokers was 6.0 points lower than the mean IQ of ex-smokers and 6.5 points lower than the mean IQ of those who had never smoked. Physical fitness, indexed by a general component extracted from measures of lung function, grip strength and walk time,

3185-529: The human genome may have impact on human diseases. Large scale GWAS has been done for the most important human diseases, including heart diseases, metabolic diseases, autoimmune diseases, and neurodegenerative and psychiatric disorders. Most of the SNPs with relatively large effects on these diseases have been identified. These findings have significantly improved understanding of disease pathogenesis and molecular pathways, and facilitated development of better treatment. Further GWAS with larger samples size will reveal

3250-769: The integrity of white matter tracts in the brain is linked to cognitive functioning and successful cognitive ageing. In one study, three general factors of white matter tract integrity, a global trait of the brain, combined to explain 10% of the variance in general intelligence, and this effect was fully mediated through processing speed. Later investigation of the associations of specific white matter tracts with g and specific cognitive abilities found that most specific tract associations were with g rather than specific abilities, though some associations with specific abilities remained after accounting for associations with g . White matter integrity has also been shown to relate to cognitive change. Specifically, white matter integrity in

3315-546: The main objective of testing the common cause hypothesis of cognitive ageing, which puts forward that age-related declines in physical and cognitive functioning share a common cause. LBC1936 participant recruitment started in 2004. Potential participants were identified using the CHI and then sent a letter about the study from the Lothian Health Board. The LBC1936 study began with the wider objective of investigating

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3380-412: The only attempts to date of any country to measure the intelligence of a complete year-of-birth in its population. By following up SMS participants in old age, the LBC studies have been able to effectively investigate long-term cognitive ageing and cognitive epidemiology due to the availability of a measure of participants' childhood intelligence. The Moray House Test No. 12, designed by Godfrey Thomson ,

3445-411: The prediction of biological traits.   SNPs have historically been used to match a forensic DNA sample to a suspect but has been made obsolete due to advancing STR -based DNA fingerprinting techniques. However, the development of next-generation-sequencing (NGS) technology may allow for more opportunities for the use of SNPs in phenotypic clues such as ethnicity, hair color, and eye color with

3510-444: The restriction of range in the LBC1921 sample. The range restriction-corrected correlation coefficients represent the best estimate of the stability of intelligence across the entire population of SMS1932 participants, and indicate that intelligence is a very stable trait. Even the corrected coefficients may underestimate the strength of the correlation, as the reliability of the test is likely below 1.0. Although age 11 intelligence

3575-402: The same number as those that communicate between the two hemispheres in the brain's largest white tissue structure, the corpus callosum . Schüz and Braitenberg note "As a rough rule, the number of fibres of a certain range of lengths is inversely proportional to their length." The proportion of blood vessels in the white matter in nonelderly adults is 1.7–3.6%. The other main component of

3640-580: The sequence flanking each SNP by alignment to the genomic sequence of large-insert clones in Genebank. These alignments were converted to chromosomal coordinates that is shown in Table 1. This list has greatly increased since, with, for instance, the Kaviar database now listing 162 million single nucleotide variants (SNVs). The nomenclature for SNPs include several variations for an individual SNP, while lacking

3705-455: The sequence of noncoding RNA. Gene expression affected by this type of SNP is referred to as an eSNP (expression SNP) and may be upstream or downstream from the gene. More than 600 million SNPs have been identified across the human genome in the world's population. A typical genome differs from the reference human genome at 4 to 5 million sites, most of which (more than 99.9%) consist of SNPs and short indels . The genomic distribution of SNPs

3770-624: The traced potential LBC participants. The LBC1921 study's main initial aim was to find molecular genetic markers of healthy cognitive ageing. This included the investigation of the influence of the E4 allele on the Apolipoprotein E ( APOE ) gene on cognitive ageing as well as testing the effects of other candidate genes for cognitive ageing. A later research focus was examining relationships involving single-nucleotide polymorphisms (SNPs) from genes linked to oxidative stress . The third and fourth waves of data collection were conducted with

3835-1089: The two alleles: homozygous A, homozygous B and heterozygous AB, leading to many possible techniques for analysis. Some include: DNA sequencing ; capillary electrophoresis ; mass spectrometry ; single-strand conformation polymorphism (SSCP); single base extension ; electrochemical analysis; denaturating HPLC and gel electrophoresis ; restriction fragment length polymorphism ; and hybridization analysis. An important group of SNPs are those that corresponds to missense mutations causing amino acid change on protein level. Point mutation of particular residue can have different effect on protein function (from no effect to complete disruption its function). Usually, change in amino acids with similar size and physico-chemical properties (e.g. substitution from leucine to valine) has mild effect, and opposite. Similarly, if SNP disrupts secondary structure elements (e.g. substitution to proline in alpha helix region) such mutation usually may affect whole protein structure and function. Using those simple and many other machine learning derived rules

3900-495: The viral RNA or DNA sample may contain SNVs. However, this nomenclature uses arbitrary distinctions (such as an allele frequency of 1%) and is not used consistently across all fields; the resulting disagreement has prompted calls for a more consistent framework for naming differences in DNA sequences between two samples. Single-nucleotide polymorphisms may fall within coding sequences of genes , non-coding regions of genes , or in

3965-435: Was .62 and therefore indicated that most of the stable variance in intelligence throughout life is attributable to genes rather than environment. Lothian Birth Cohort data has also been a part of GWA studies for various medical outcomes including cancer, stroke, lung function, arterial pressure and platelet formation. Structural magnetic resonance imaging brain scans from LBC1936 participants have been used to observe that

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4030-536: Was a strong correlation between scores at ages 11 and 70 of .67. The most consistent genetic finding from the LBC studies has been that the E4 allele on the APOE gene, which had previously been known to be a risk factor for late-onset Alzheimer's disease , is also adversely linked to non-pathological cognitive function and change. In an early LBC1921 study, E4 allele status was unrelated to Moray House Test scores at age 11, but at age 80 those with an E4 allele scored lower than those without an E4 allele, indicating that

4095-469: Was associated with successful cognitive ageing at age 79 in the LBC1921. Physical activity has also been associated with successful cognitive ageing in the LBC1936, as it remained associated with age 70 general cognitive ability and processing speed after controlling for intelligence at age 11. One of the strengths of the LBC study designs is that they enable tests of reverse causation in associations between intelligence and other variables. Reverse causation

4160-731: Was carried out on 4 June 1947, and tested the intelligence of 70,805 children, nearly all of Scotland's 1936-born population. The SMS data was rediscovered by Ian Deary and Lawrence Whalley in the late 1990s. The data had been in the Charteris Land building of the Moray House School of Education at the University of Edinburgh, which was being rented by the SCRE. Recruitment for the Aberdeen area-based follow-up studies of

4225-669: Was used in both Scottish Mental Surveys. It is a valid intelligence test that consists of 75 items of a variety of types including: following directions; word classification; analogies; practical items; reasoning; arithmetic; and spatial items. The SMS1932 was funded by the Carnegie Corporation as part of the International Examination Inquiry. It aimed to find out how many children in Scotland were "mentally deficient" and gather information on

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