Fluid Cognitive Abilities Research Articles

Four successful tests of the Cognitive Differentiation–Integration Effort hypothesis

The Cognitive Differentiation–Integration Effort (CD–IE) hypothesis predicts that the dimension of life history speed (K) regulates the strength of the correlation among cognitive abilities, such that individuals with higher K exhibit more weakly integrated abilities than those with lower K. It is predicted that this effect takes place independently of the level of g owing to the absence of an individual differences level correlation between K and g. CD–IE was examined using two student samples: (1) an all female sample (N=121), using the ALHB as a measure of K and the two SILS subtests of g; and (2) a combined male and female sample (N=346), using a shorter three-indicator (“Trifecta”) measure of K, a general creativity measure comprised of two subscales (writing and drawing “creative performance”), and the APM-18 measure of fluid cognition. A third, population-representative sample was obtained from the NLSY (N=11,907). A K-Factor was constructed from convergent measures of subjective well-being, sociability, interpersonal trust, internal locus of control, and delay of gratification, and a g-factor was constructed from the 10 subscales of the ASVAB. A fourth sample, addressing the question of ethnic differences was collected encompassing eight different ethnic groups with a combined 107 specific ability correlations with g. An aggregate K-Factor was constructed for this sample based on convergent population-level indicators of longevity, total fertility rates and infant mortality. Utilizing the Continuous Parameter Estimation Model, in student sample 1 a significant CD–IE effect was found on the SILS Abstract subtest (β=−.215), but not on the SILS Verbal subtest (β=.069). In student sample 2, CD–IE was observed on the general creativity measure (β=−.127), but not on the fluid cognitive ability measure (β=−.057). Significant effects were also observed on both the written and drawing creative output subscales (β=−.189 and −.183 respectively). In sample 3 (the NLSY), generally statistically significant but small-magnitude CD–IE effects were observed among all 10 ASVAB subtests (mean effect size β=−.032). In sample four, a near-significant CD–IE effect was detected (β=−.167). Controlling for subtest skew reduces the mean effect sizes across individual differences samples (β=−.071 in the student samples, −.027 in the NLSY), but boosted it to significance in the ethnic differences sample (β=−.179). Controlling for the skew of residuals reversed the signs of the CD–IE effects on the ASVAB Words and Comprehension subscales, and also on the SILS Verbal subscale, but amplified the magnitudes of the mean effects in the student and NLSY samples (β=−.036 and −.131), while reducing the effect size slightly in the ethnic-differences sample (β=−.172). In the individual differences samples, these effects were demonstrated to be unconfounded with sex of respondent and also unrelated to the Jensen effect. The apparent independence of the effect from both level of g and subtest g-loading suggests intriguing commonalities with the Lynn–Flynn effect.

Skill demand and the comparative advantage of age: Jobs tasks and earnings from the 1980s to the 2000s in Germany

We study the impact of rapid technological change on age and cohort variation in type of work and wages among German men for the 1986–2006 period. Using a task-based approach, we analyze the consequences that technological progress had on changes in the distribution of tasks performed by the men and the relative wages they received. Technological changes implied fewer physically demanding job tasks and a growing use of cognitive skills, particularly tasks where fluid cognitive abilities are important. A number of earlier physiological and cognitive studies suggest that younger workers have a comparative advantage in terms of physically demanding work and fluid cognitive abilities.Our findings confirm that while physical task use has generally decreased for most age groups, workers in their 50s experienced a more rapid growth not only in cognitively intense tasks than those in their 30s, but also in tasks that were intense in the use of fluid cognitive abilities. Following cohorts over time, we find that all cohorts, also when education was controlled for, experienced a rapid increase in fluid task use by the 2000s. Further, the relative earnings of those in their 50s compared to younger age groups increased – possibly as result of a shift towards cognitively based work tasks where age-earnings curves are relatively steep.

Explaining adult age differences in decision‐making competence

ABSTRACTStudies on aging‐related changes in decision making report mixed results. Some decision‐making skills decline with age, while others remain unchanged or improve. Because fluid cognitive ability (e.g., reasoning, problem solving) deteriorates with age, older adults should perform worse on decision‐making tasks that tap fluid cognitive ability. However, performance on some decision‐making tasks may require experience, which increases with age. On those tasks, older adults should perform at least as well as younger adults. These two patterns emerged in correlations between age and component tasks of Adult Decision‐Making Competence (A‐DMC), controlling for demographic variables. First, we found negative relationships between age and performance on two tasks (Resistance to Framing, Applying Decision Rules), which were mediated by fluid cognitive ability. Second, performance on other tasks did not decrease with age (Consistency in Risk Perception, Recognizing Age‐group Social Norms) or improved (Under/Overconfidence, Resistance to Sunk Costs). In multivariate analyses, performance on these tasks showed independent positive relationships to both age and fluid cognitive ability. Because, after controlling for fluid cognitive ability, age becomes a proxy for experience, these results suggest that experience plays no role in performing the first set of tasks, and some role in performing the second set of tasks. Although not all decision‐making tasks showed age‐related declines in performance, older adults perceived themselves as worse decision makers. Self‐ratings of decision‐making competence were related to fluid cognitive ability and to decision‐making skills that decreased with age—but not to decision‐making skills that increased with age. Copyright © 2010 John Wiley & Sons, Ltd.

Validity evidence for the situational judgment test paradigm in emotional intelligence measurement

To date, various measurement approaches have been proposed to assess emotional intelligence (EI). Recently, two new EI tests have been developed based on the situational judgment test (SJT) paradigm: the Situational Test of Emotional Understanding (STEU) and the Situational Test of Emotion Management (STEM). Initial attempts have been made to examine the construct-related validity of these new tests; we extend these findings by placing the tests in a broad nomological network. To this end, 850 undergraduate students completed a personality inventory, a cognitive ability test, a self-report EI test, a performance-based EI measure, the STEU, and the STEM. The SJT-based EI tests were not strongly correlated with personality and fluid cognitive ability. Regarding their relation with existing EI measures, the tests did not capture the same construct as self-report EI measures, but corresponded rather to performance-based EI measures. Overall, these results lend support for the SJT paradigm for measuring EI as an ability.

Information search and decision making: Effects of age and complexity on strategy use.

The impact of task complexity on information search strategy and decision quality was examined in a sample of 135 young, middle-aged, and older adults. We were particularly interested in the competing roles of fluid cognitive ability and domain knowledge and experience, with the former being a negative influence and the latter being a positive influence on older adults' performance. Participants utilized 2 decision matrices, which varied in complexity, regarding a consumer purchase. Using process tracing software and an algorithm developed to assess decision strategy, we recorded search behavior, strategy selection, and final decision. Contrary to expectations, older adults were not more likely than the younger age groups to engage in information-minimizing search behaviors in response to increases in task complexity. Similarly, adults of all ages used comparable decision strategies and adapted their strategies to the demands of the task. We also examined decision outcomes in relation to participants' preferences. Overall, it seems that older adults utilize simpler sets of information primarily reflecting the most valued attributes in making their choice. The results of this study suggest that older adults are adaptive in their approach to decision making and that this ability may benefit from accrued knowledge and experience.

Childhood intelligence and brain white matter hyperintensities predict fluid intelligence age 78–81 years: a 1921 Aberdeen birth cohort study

to evaluate the role of childhood intelligence and white matter hyperintensities (WMH) in the prediction of the trajectory of fluid intelligence in healthy old people from age 78 to 81. observational follow-up study from 1999 to 2002. a university teaching hospital in Aberdeen, UK. a total of 106 volunteers born in 1921, with childhood intelligence records at 11, recruited 1997-98 to a follow-up study. participants underwent brain MRI in 1999-2000, to obtain measurements of brain WMH using Scheltens' scale and a test of fluid intelligence (Raven's Progressive Matrices) on three occasions between 1999 and 2002. in a latent growth model, we found a significant association between childhood intelligence and the intercept, but not the slope, of fluid cognitive ability in late adulthood. Similarly, baseline WMH score was associated with the intercept of late life cognitive ability, but not the slope. Age at imaging was associated with slope but not intercept. There was no significant association between sex and intercept or slope of late life cognitive ability. results suggest that brain MRI measures of WMH (attributed to cerebrovascular disease) and childhood intelligence significantly contribute to late life fluid cognitive ability but not to the trajectory of age-related change in fluid intelligence. We also show that age is associated with the cognitive trajectory from 78 to 81 years, even within our narrow age range sample. This may be a consequence of the recruitment pattern, with those having greater WMH burden, and who subsequently declined, being recruited later in the study.

What cognitive abilities are involved in trail-making performance?

The cognitive abilities involved in the Connections (Salthouse, et al., 2000) version of the trail making test were investigated by administering the test, along with a battery of cognitive tests and tests of complex span and updating conceptualizations of working memory, to a sample of over 3600 adults. The results indicate that this variant of the trail making test largely reflects individual differences in speed and fluid cognitive abilities, with the relative contributions of the two abilities varying according to particular measure of performance considered (e.g., difference, ratio, or residual). Relations of age on trail making performance were also examined. Although strong age differences were evident in the Connections and working memory measures, with both sets of variables there was nearly complete overlap of the age differences with individual differences in speed and fluid cognitive abilities.

Cognitive correlates of cross-sectional differences and longitudinal changes in trail making performance

A total of 1,576 adults between 18 and 95 years of age performed a battery of cognitive tests and the Connections version of the Trail Making Test twice, with an average interval between assessments of 2.5 years. Consistent with previous results, speed ability and fluid cognitive ability were strongly correlated with trail making performance. Neither speed nor fluid cognitive ability at the first occasion predicted longitudinal changes in trail making performance, but there were significant correlations between the changes in these abilities and the changes in trail making performance. These results indicate that individual differences in speed and fluid cognitive abilities are associated with individual differences in trail making performance both at a single point in time (cross-sectional differences) and in the changes over time (longitudinal changes).

Fluid cognitive ability is associated with greater exposure and smaller reactions to daily stressors.

The authors of this study investigated whether fluid cognitive ability predicts exposure and emotional reactivity to daily stressors. A national sample of adults from the Midlife in the United States study and the National Study of Daily Experiences (N = 1,202) who had a mean age of 57 years (SD = 12; 56% women, 44% men) completed positive and negative mood reports as well as a stressor diary on 8 consecutive evenings via telephone. Participants also completed a telephone-based battery of tests measuring fluid cognitive ability. Higher levels of fluid cognitive ability were associated with greater exposure to work- and home-related overload stressors. Possessing higher levels of fluid cognitive ability was associated with smaller stressor-related increases in negative mood, primarily for interpersonal tensions and network stressors, and smaller stressor-related decreases in positive mood for interpersonal tensions. Furthermore, fluid cognitive ability was unrelated to subjective severity ratings of the stressors reported. Discussion focuses on the role of fluid cognitive ability in daily stress processes.

Cognition and Illness Experience are Associated with Illness Knowledge Among Older Adults with Hypertension

We investigated how cognitive abilities and illness experience relate to illness knowledge. One hundred and forty-eight community-dwelling older adults including hypertensive patients and healthy adults completed a battery that measured illness knowledge, fluid cognitive abilities, crystallized abilities, and health history. Results suggested that hypertension knowledge was primarily associated with illness duration (despite a negative relationship between illness duration and fluid ability) and crystallized ability. Also, greater illness knowledge was associated with an illness perception that may be more consistent with self-care (e.g., greater sense of control). Implications for patient education and training are discussed.

Cognition and Illness Experience are Associated with Illness Knowledge among Older Adults with Hypertension

We investigated how cognitive abilities and illness experience relate to illness knowledge. One hundred and forty-eight community-dwelling older adults including hypertensive patients and healthy adults completed a battery that measured illness knowledge, fluid cognitive abilities, crystallized abilities, and health history. Results suggested that hypertension knowledge was primarily associated with illness duration (despite a negative relationship between illness duration and fluid ability) and crystallized ability. Also, greater illness knowledge was associated with an illness perception that may be more consistent with self-care (e.g., greater sense of control). Implications for patient education and training are discussed.

Birth Parameters and Cognitive Ability in Older Age: A Follow-Up Study of People Born 1921–1926

Background: Birth weight throughout the normal range correlates with cognitive ability in childhood. Some studies suggest this may persist into adulthood, but it is unclear whether this continues into old age. Objective: To investigate the relationship between birth parameters (birth weight, birth length, placental weight and social class) and cognitive ability in old age. Methods: 128 community-dwelling volunteers born in one hospital in Edinburgh, UK, between 1921 and 1926 had birth details extracted from the records. All aged 75–81 underwent cognitive tests. The National Adult Reading Test (NART) was used to estimate prior ability. Tests of fluid cognitive ability showed positive intercorrelations, and therefore a general cognitive factor (g) was extracted using principal components analysis. Results: Estimated prior ability (NART) correlated with birth length (r = 0.25, p = 0.02), and non-significantly with birth weight (r = 0.15, p = 0.19). There were no statistically significant correlations between birth parameters and cognitive ability aged around 80 (birth weight r = 0.12, p = 0.27; length r = 0.19, p = 0.08). Placental weight was not associated with cognitive ability. There was a trend towards an association between social class at birth and prior cognitive ability (more deprivation predicting poorer performance) (rho = –0.17, p = 0.06). Social class was not significantly associated with cognitive ability in old age (rho = 0.07, p = 0.47), or with estimated cognitive change (rho = –0.03, p = 0.73). Conclusion: In a small sample of community-dwelling older people, an influence was detected from birth to earlier cognitive ability using a test of crystallized intelligence. However, this effect was not significant into old age. In this sample, social class at birth did not affect later cognitive ability. The effect size of early life influences on cognition is small, with birth parameters explaining about 1% of the variance. Research with larger samples should consider influences operating across the whole life course, and their relative importance over time.

Increases in the verbal and fluid cognitive abilities of disadvantaged children attending preschool in the Netherlands

Abstract The current longitudinal study examined the development of general cognitive abilities of 4–6-year-old children of low-income, ethnic-minority families in preschool over two and a half years by determining the changes in general, and in verbal and fluid cognitive abilities, relative to age norms, using an intelligence test. The results revealed significant increases over time, relative to age norms, in full scale and in both verbal and fluid intelligence test scores of disadvantaged children, with medium effect sizes. These gains in measured intelligence were moderated by children's home language and age. Children who gained most also profited most from their increased abilities with respect to emergent school skills. Gains in verbal intelligence predicted emergent school vocabulary, but gains in fluid intelligence did not. Overall, gains in fluid intelligence predicted emergent math skills, and gains in verbal intelligence predicted emergent math skills only among older children.

O4-03-05: The potential role of copper in Alzheimer‘s disease

Alzheimer's disease (AD) is a devastating brain disorder clinically characterized by progressive loss of characteristic cognitive abilities. Increasing evidence suggests a disturbed copper (Cu) homeostasis to be associated with the pathological processes. In this analysis we present baseline results of an ongoing double–blind placebo–controlled randomized trial on the efficacy of copper in patients with mild to moderate AD. The relationship between plasma Cu levels cerebrospinal fluid (CSF) markers (Aβ42, Tau and Phospho–Tau) and cognitive abilities using the Alzheimer's disease Assessment Scale–cognitive subscale (ADAS–cog) was investigated in the first 33 patients. Statistical analysis revealed a negative correlation between plasma Cu levels and cognitive decline (r=−0.49; p<0.01). Patients with low plasma Cu (mean 82 ± SD 9) had significantly higher ADAS–cog values (mean 23 ± SD 7), than patients with medium plasma Cu (mean 110 ± SD 7), who exhibited lower ADAS–cog scores (mean 16 ± SD 4; ANOVA, p<0.0001). Despite the fact that all patients had plasma Cu levels within the physiological range between 65 μg and 165 μg/dL, 87.5% of the patients revealed a significant negative correlation between plasma Cu and ADAS–cog. Univariate tests revealed significantly reduced plasma Cu (–12.7%; F = 7.05; df = 1, 25; p = 0.014) and ceruloplasmin (–14.1%; F = 9.44; df = 1, 24; p = 0.005) levels in patients with aberrant CSF biomarker concentrations. These findings support the hypothesis of a mild Cu deficiency in most AD patients.

Toward a revised theory of general intelligence: Further examination of fluid cognitive abilities as unique aspects of human cognition

Primary issues raised by the commentaries on the target article relate to (1) the need to differentiate distinct but overlapping aspects of fluid cognition, and (2) the implications that this differentiation may hold for conceptions of general intelligence. In response, I outline several issues facing researchers concerned with differentiation of human cognitive abilities and suggest that a revised and expanded theory of intelligence is needed to accommodate an increasingly diverse and varied empirical base.

Surgically Restoring Portal Blood Flow to the Liver in Children With Primary Extrahepatic Portal Vein Thrombosis Improves Fluid Neurocognitive Ability

Children with primary extrahepatic portal vein thrombosis (EHPVT) have portal-systemic shunting, which may lead to disturbed neurocognitive function similar to portal-systemic encephalopathy (PSE) seen with chronic liver disease and cirrhosis. The functions most affected are those involving fluid cognitive ability, which comprise neurocognitive domains such as attention, processing speed, and short-term memory, that are particularly vulnerable to systemic illness or diffuse neurologic insult. We determined the fluid cognitive ability of children with EHPVT and whether surgically restoring portal blood flow by mesenteric left portal vein bypass (MLPVB) improved it. Twelve children with EHPVT and no overt PSE underwent comprehensive neurocognitive testing before and 1 year after undergoing surgery with intent to perform MLPVB. The evaluations sampled 4 functional domains at both time points: (1) neurobehavioral (behavior, emotional, executive functioning); (2) broad cognitive (intelligence, achievement); (3) fluid ability (attention, mental speed, working memory, memory encoding); and (4) visual motor (drawing, fine motor). Tasks in the fluid-ability and visual-motor domains were expected to be especially sensitive to adverse effects of EHPVT and to be most likely to show improvement with MLPVB. The test group consisted of 8 subjects who underwent successful MLPVB, and the comparison group was composed of 3 patients who received distal splenorenal shunts and one whose MLPVB failed. Both groups demonstrated similar fluid cognitive ability at initial evaluation. Successful MLPVB resulted in significantly improved fluid cognitive function: in the fluid cognitive domain, significant improvements were seen for the hit reaction time variability in the Conner's Continuous Performance Test, the attention scale of the Cognitive Assessment System, and immediate verbal memory in the Children's Memory Scale. In the visual-motor domain, z scores on the Grooved Pegboard Test improved. No improvement was observed in the comparison group. The results show that surgically restoring portal flow to the liver in children with primary EHPVT results in improved fluid cognitive ability. Subjects showed some neurocognitive abnormalities involving mainly fluid cognitive ability consistent with minimal PSE seen in adults with chronic liver disease. Cognitive defects in patients with minimal PSE seem to relate primarily to attention and fine motor skill, and although affected patients can function in everyday life, they are at risk for performance deficits in educational and vocational situations requiring the ability to pay close attention and react quickly (eg, driving, employment in manufacturing). The tests we administered in these domains are pediatric equivalents to measures used to detect minimal PSE in adults and should detect abnormalities in the same functional domains. Our results suggest that a narrow battery of tests could be used to detect minimal PSE in children in a manner similar to the 5-test battery used in adults, eliminating the need for the comprehensive and broad testing we performed. Our findings suggest that shunting of portal blood from the liver in primary EHPVT can result in PSE and question whether it is as benign a disease as previously thought. The importance of our findings is twofold. For understanding the pathophysiology of PSE, we have shown that restoring blood flow to the liver improves cognitive function in children with EHPVT. For therapy for EHPVT, it becomes clear that MLPVB is an excellent treatment option. It is effective for treating the complications of portal hypertension and provides effective portal blood flow that other medical and surgical therapies do not. The findings provide additional evidence that primary EHPVT should be considered curable by MLPVB. However, comparison of overall risks and benefits of MLPVB with those of other therapeutic options and longer-term outcome studies must be completed before MLPVB can be fully endorsed as the best treatment for EHPVT in children. Surgical restoration of portal venous flow to the liver in children with primary EHPVT by MLPVB improves fluid cognitive ability. MLPVB should be considered in treating primary EHPVT, because it corrects portal blood flow and could optimize learning potential.

Åldrande och kognition

Hassing, L.B. & Johansson, B. (2005). Aging and cognition. Nordisk Psykologi, 57, 1, 4–20. This article provides an overview of cognitive aging research with focus on normal aging. Results from longitudinal studies have revealed that cognitive abilities are more stable than early findings from cross-sectional studies indicated. It is also clear that crystallized abilities, such as knowledge, vocabulary, and verbal abilities are mostly stable or even may show an improvement across the adult life-span, whereas fluid abilities such as speed, executive function, working memory, and episodic memory are negatively affected in aging. Although fluid cognitive abilities tend to decline with age crystallized abilities can provide cognitive support and in this respect compensate deficits in everyday problem solving. Much research has been conducted in the last decades to identify factors that contribute to cognitive aging. It is well established that genetic, health-related (e.g., hypertension, diabetes, homocysteine, and vitamin status), as well as lifestyle factors (e.g., education, substance use, physical- and social activities) are of importance for cognitive functioning. Some of the age-related variations in cognitive performance is also mediated by changes in other cognitive processes such as speed. There is, however, still age-related variation that has not been accounted for which emphasize the need for further research and suggest that multiple aging processes affect our central nervous system and thereby various mechanisms involved in cognitive functioning.

P3a and Neuropsychological ‘Frontal’ Tests in Aging

The purpose of this study was to investigate the relationship between the auditory P3a and neuropsychological tests related to frontal or prefrontal function in aging. Two hypotheses were tested: (1) P3a correlates more strongly with neuropsychological tests of frontal/prefrontal function than P3b does. (2) P3a correlates more strongly with neuropsychological tests of frontal/prefrontal function than with tests of general mental abilities. Twenty-seven adults (22-92 years, mean age 58 years) completed four neuropsychological tests assumed related to frontal or prefrontal function (Stroop, TMT, CTT, COWAT), two tests of general fluid cognitive ability (matrices and block design subtests from WASI; Wechsler, 1999), and one ERP task. The data gave support to the assumption that P3a measures frontal cognitive functioning of the same sort that is indexed by different Stroop measures. For most other tests of prefrontal function, the correlations with P3a and P3b are not very different, and so P3a can only to a modest extent be said to index these neuropsychological functions better than the traditional P3b.

Working memory assessments at school entry as longitudinal predictors of National Curriculum attainment levels

AbstractA longitudinal study of 54 children aged between 4 and 7 years of age investigated whether measures of working memory skills taken shortly after school entry served as useful predictors of children’s attainment levels in National Curriculum assessments at Key Stage 1. Early working memory scores were found to be highly significant predictors of children’s subsequent levels of attainment in literacy, but not in mathematics. Compared with the local education authority baseline assessments also administered at 4 years of age that are designed in large part to predict later attainments, working memory scores accounted for unique variance in children’s spelling and writing scores at 7 years. These findings point to the utility of combining knowledge-based assessments with measures of fluid cognitive ability in order to obtain the best estimates of a child’s chances of future academic success.

Dual Voxel Proton Magnetic Resonance Spectroscopy in the Healthy Elderly: Subcortical-Frontal Axonal N-Acetylaspartate Levels Are Correlated with Fluid Cognitive Abilities Independent of Structural Brain Changes

The published literature suggests that degeneration of the subcorticofrontal networks may underlie cognitive ageing, but appropriate methods to examine this in vivo have been lacking. Proton Magnetic Resonance Spectroscopy (1H-MRS) has now been used in a number of clinical studies to assess cerebral pathophysicochemistry and recently has been utilized to examine the relationship between neurochemical markers and cognitive functioning in normal individuals. Results have been somewhat conflicting and difficult to interpret. To further clarify the role of the cognitive spectroscopy technique, we measured N-acetylaspartate (NAA) levels in the frontal subcortical white matter and the occipitoparietal grey matter and correlated them with performance in different cognitive domains in a group of twenty healthy elderly individuals. Subjects underwent whole brain T1- and T2-weighted magnetic resonance imaging (MRI), dual voxel short echo-time 1H-MRS, and a comprehensive neuropsychological assessment. Individual tests of executive and attentional abilities, and a principal components composite score reflecting these skills, but not measures of memory or verbal abilities, were correlated with NAA concentration in the frontal white matter only. These relationships were independent of other neurocognitive predictors of executive impairment such as age, midventricular dilation, frontal white matter disease, and presenescent verbal proficiency. This study suggests the ability of 1H-MRS to differentiate anatomically distinct neurochemical markers related to specific cognitive abilities. In particular, neurometabolic fitness of the frontal subcortical-cortical axonal fibers may be important in mediating fluid intellectual processing. Longitudinal MRS studies are required to determine if the present results reflect different rates of neurocellular degeneration or preexisting individual differences in neuronal density.