Fluid Ability Research Articles

The effects of an engaged lifestyle on cognitive vitality: A field experiment.

Experimental studies on cognitive training have suggested that the effects of experience are narrow in augmenting or maintaining cognitive abilities, while correlational studies report a wide range of benefits of an engaged lifestyle, including increased longevity, resistance to dementia, and enhanced cognitive flexibility. The latter class of evidence is ambiguous because it is possible that it is simply the case that those with relatively better cognitive vitality seek out and maintain a wider range of activities. The authors report data from a field experiment in which older adults were randomly assigned to participate in a program intended to operationalize an engaged lifestyle, built on a team-based competition in ill-defined problem solving. Relative to controls, experimental participants showed positive change in a composite measure of fluid ability from pretest to posttest. This study, thus, provides experimental evidence for the proposition that engagement, in the absence of specific ability training, can mitigate age-related cognitive declines in fluid ability.

Not your parents' test scores: cohort reduces psychometric aging effects.

Increases over birth cohorts in psychometric abilities may impact effects of aging. Data from 2 cohorts of the Long Beach Longitudinal Study, matched on age but tested 16 years apart, were modeled over ages 55-87 to test the hypothesis that the more fluid abilities of reasoning, list and text recall, and space would show larger cohort differences than vocabulary. This hypothesis was confirmed. At age 74, average performance estimates for people from the more recently born cohort were equivalent to those of people from the older cohort when they were up to 15 years younger. This finding suggests that older adults may perform like much younger ones from the previous generation on fluid measures, indicating higher levels of abilities than expected. This result could have major implications for the expected productivity of an aging workforce as well as for the quality of life of future generations. However, cohort improvements did not mitigate age declines.

Broken eggs decrease pH of rainbow trout (Oncorhynchus mykiss) ovarian fluid

Low pH of ovarian fluid is attributed to its inability to activate sperm motility. In the present study we sought if broken eggs are reason for the decrease of ovarian fluid pH. We examined if 1) there is relationship between turbidity of ovarian fluid (indicator of presence of broken eggs) and pH, and 2) there is a decrease in ovarian fluid pH after addition of broken eggs. We found a negative relationship between the turbidity and ovarian fluid pH. Addition of the content of broken eggs to ovarian fluid caused a decrease of pH and a decrease in ovarian fluid ability to activate sperm motility. Therefore it can be suggested that content of broken eggs decreases or negates the ability of ovarian fluid to activate sperm motility due to a decrease of pH.

Ability EI as an intelligence? Associations of the MSCEIT with performance on emotion processing and social tasks and with cognitive ability

Associations among the MSCEIT, a broad-bandwidth measure of ability emotional intelligence (EI), self-report EI, social perception ability, psychometric intelligence and performance on inspection time (IT) tasks, which assessed the speed of processing of emotional and non-emotional information were investigated in two student samples (N=99, 199). The main findings were that MSCEIT scores were unrelated to fluid ability or speed of non-emotional information processing as assessed by IT, but evidence for associations of MSCEIT scores with crystallised ability was found. Positive associations were found between MSCEIT scores, self-report EI and some emotion/social task scores. The results suggest that EI as assessed by the MSCEIT has some properties of an intelligence and is more closely related to crystallised than to fluid ability. The relatively small MSCEIT/g c correlations suggest that the MSCEIT is not a pure ability measure, although restriction of range in the samples used may also be relevant. More work, and the development of new measures, is required to determine whether performance EI has a fluid component.

Children Becoming More Intelligent: Can the Flynn Effect be Generalized to Other Child Intelligence Tests?

In this article, time effects on intelligence test scores have been investigated. In particular, we examined whether the “Flynn effect” is manifest in children from the middle and higher IQ distribution range, measured with a child intelligence test based on information processing principles—the Leiden Diagnostic Test. The test was administered to two independent groups of children—one tested recently, another tested 25 years ago. Analyses of the test scores showed that over time, children's IQ scores increased at least 15 points for those in the higher SES group and 8 points for those in the middle SES group. In a two-factor solution, scores on the Spatial-Analytic factor increased more than scores on the Verbal factor. Inspection of the three-factor solution showed that gains on the Spatial-Analytic factor were about .9 SD, on the Memory factor .8 SD, and on the Verbal factor .6 SD. The finding that performance or fluid abilities, measuring on-the-spot problem-solving, are more susceptible to change over time than crystallized abilities, measuring the results of learning in the past, is consistent with our hypothesis. However, the finding that aspects of children's memory are also susceptible to change over time was unexpected. It is hypothesized that the working memory system may have become more efficient over time because more information has tobe absorbedatamuch younger age, and coping with a stimulating environment may require a more efficient memory system.

Effects of age and schooling on intellectual performance: Estimates obtained from analysis of continuous variation in age and length of schooling

The effects of age and schooling on different aspects of intellectual performance, taking track of study into account, are investigated. The analyses were based on military enlistment test scores, obtained by 48,269 males, measuring Fluid ability (Gf), Crystallized intelligence (Gc), and General visualization (Gv) ability. A regression method, relying on simultaneous variation in age and length of schooling at the time of the testing, was used. The results showed that both age and schooling increase performance, with the exception of the test which primarily measures Gf, for which the age effect was negative. The effects of schooling were considerably stronger than the effects of age, and there was a pattern of differential schooling effects on different tests which matched the curricular emphasis of the programs. The estimates of the strength of the schooling effect obtained with this new method were generally in good agreement with the results obtained in previous research.

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.

Is there a general task switching ability?

Participants were tested on two analogous task switching paradigms involving Shape/Size tasks and Vertical/Horizontal tasks, respectively, and three measures of psychometric intelligence, tapping fluid, crystallized and perceptual speed abilities. The paradigms produced similar patterns of group mean reaction times (RTs) and the vast majority of the participants showed switching cost (switch RT minus repeat RT), mixing cost (repeat RT minus single-task RT) and congruency effects. The shared intra-individual variance across paradigms and with psychometric intelligence served as criteria for general ability. Structural equations modeling indicated that switching cost with ample preparation (“residual cost”) and mixing cost met these criteria. However, switching cost with little preparation and congruency effects were predominantly paradigm specific.

Measuring Auditory Inspection Time in Primary School Children

This study investigated the relationship between visual inspection time (VIT) and a new measure of auditory inspection time (AIT: see Parker, Crawford, & Stephen, 1999 ). The purpose was twofold: first, to understand the generality of the mechanism underpinning performance on visual IT tasks (VIT); second, to evaluate the efficacy of this new auditory task. Participants were 80 primary school children aged 10–12 years. They each completed AIT, VIT, and a marker test for each of general speediness (Gs), fluid ability (Gf), and crystallized ability (Gc). AIT and VIT were positively correlated with each other, and they both correlated with the marker of Gs. However, the data suggest that the nature of IT tasks changes as task difficulty increases. Thus, IT appears to be a purer measure of processing speed at longer exposure durations. These findings are discussed in relation to the methodology employed in IT estimation and in light of recent comments concerning the psychological complexity of IT.

Age changes in processing speed as a leading indicator of cognitive aging.

Bivariate dual change score models were applied to longitudinal data from the Swedish Adoption/Twin Study of Aging to compare the dynamic predictions of 2-component theories of intelligence and the processing speed theory of cognitive aging. Data from up to 5 measurement occasions covering a 16-year period were available from 806 participants ranging in age from 50 to 88 years at the first measurement wave. Factors were generated to tap 4 general cognitive domains: verbal ability, spatial ability, memory, and processing speed. Model fitting indicated no dynamic relationship between verbal and spatial factors, providing no support for the hypothesis that age changes in fluid abilities drive age changes in crystallized abilities. The results suggest that, as predicted by the processing speed theory of cognitive aging, processing speed is a leading indicator of age changes in memory and spatial ability, but not verbal ability.

Are Individual Differences in Performance on Perceptual and Cognitive Optimization Problems Determined by General Intelligence?

Studies of human problem solving have traditionally used deterministic tasks that require the execution of a systematic series of steps to reach a rational and optimal solution. Most real-world problems, however, are characterized by uncertainty, the need to consider an enormous number of variables and possible courses of action at each stage in solving the problem, and the need to optimize the solution subject to multiple interacting constraints. There are reliable individual differences in people’s abilities to solve such realistic problems. It also seems likely that people’s ability to solve these difficult problems reflects, or depends on, their intelligence. We report on a study of N = 101 adults who completed a series of visual optimization problems (Traveling Salesperson, Minimum Spanning Tree, and Generalized Steiner Tree Problems), as well as a cognitive optimization problem (a version of the Secretary Problem). We also characterized these individuals along three relevant and important cognitive abilities dimensions—fluid ability, visuo-spatial ability, and cognitive processing speed. Modeling of covariance structures indicated that performance on both types of optimization problems relies on general intelligence and raises the possibility that they can be used to assess intelligence.

Bateria de habilidades cognitivas Woodcock-Johnson III: validade de construto

O objetivo da pesquisa foi investigar a validade de construto da Bateria Woodcock-Johnson III (WJ-III) para avaliar as habilidades cognitivas de brasileiros. Dois estudos foram elaborados, o primeiro com amostra de 375 participantes (220 mulheres, 155 homens), de 7 a 18 anos, e o segundo com 64 crianças (36 meninas, 28 meninos), 7 a 12 anos. Oito subtestes da WJ-III e o teste do Desenho da Figura Humana (DFH-III) foram administrados. Os resultados analisados apontaram a consistência interna dos itens da WJ-III, por meio da Correlação de Pearson, assim como diferenças significativas entre faixas etárias nos subtestes estudados, utilizando-se as Análises da Variância Multivariada e Univariada. Correlações significativas foram observadas entre a WJ-III e o DFH-III nas habilidades espacial, fluida e na rapidez de processamento. Conclui-se que a WJ-III possui validade de construto para crianças e jovens brasileiros.

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.

A temporal–contextual retrieval account of complex span: An analysis of errors

Complex working memory span tasks have been shown to predict performance on a number of measures of higher-order cognition including fluid abilities. However, exactly why performance on these tasks is related to higher-order cognition is still not known. The present study examined the patterns of errors made on two common complex span tasks. The results suggest that the patterns of errors made on these tasks are an important indicator of the processes that underlie performance and point to the importance of temporal–contextual cues. Furthermore, the individual differences data suggest that low scoring participants do not make more of each type of error at all serial positions, but rather the variability is localized to a few theoretically meaningful positions for each error type. The results suggest that low scoring participants have less precise temporal–contextual cues which leads to an inefficient search of memory.

Selective increase of cortical thickness in high-performing elderly—structural indices of optimal cognitive aging

The aim of this study was to identify cortical areas important for optimal cognitive aging. 74 participants (20–88 years) went through neuropsychological tests and two MR sessions. The sample was split into two age groups. In each, every participant was classified as “high” or “average” on fluid ability tests and on neuropsychological tests related to executive function. The groups were compared with regard to thickness on a point-by-point basis across the entire cortical mantle. The old high fluid performers had thicker cortex than the average performers in large areas of cortex, while there was minimal difference between the groups of high vs. average executive function. Furthermore, the old group with high fluid function had thicker cortex than the young participants in the posterior cingulate and adjacent areas. Further analyses showed that the latter was a result of a complex aging pattern, differing between the two performance groups, with decades of cortical thickening and subsequent thinning.

The Longitudinal Relationship between Processing Speed and Cognitive Ability: Genetic and Environmental Influences

Goals of the present study were to investigate the relationship between age changes in speed and cognition and the genetic and environmental influences on that relationship. Latent growth models and quantitative genetic methods were applied to data from the Swedish Adoption/Twin Study of Aging. The sample included 778 individuals from both complete and incomplete twin pairs who participated in at least 1 of 4 testing occasions over a 13-year-period. Four factors were constructed from 11 cognitive measures: verbal, spatial, memory, and processing speed. Results indicate that for measures of fluid abilities, the explanatory value of processing speed is paramount for both mean cognitive performance and acceleration with age. A significant proportion of the genetic influences on cognitive ability arose from genetic factors affecting processing speed. For measures of fluid abilities, it is not the linear age changes but the accelerating age changes in cognition that share genetic variance with processing speed.

Simple and complex memory spans and their relation to fluid abilities: Evidence from list-length effects

Complex (working memory) span tasks have generally shown larger and more consistent correlations with higher-order cognition than have simple (or short-term memory) span tasks. The relation between verbal complex and simple verbal span tasks to fluid abilities as a function of list-length was examined. The results suggest that the simple span-fluid abilities correlation changes as a function of list-length, but that the complex span-fluid abilities correlation remains constant across list-lengths from lists as short as two items. Furthermore, regression and factor analytic results suggested that the longest simple span list-lengths and all of the complex span list-lengths had both unique and shared variability in predicting fluid abilities, but that estimates of primary memory did not uniquely predict fluid abilities. It is suggested that complex spans, generally, predict higher-order cognition to a greater extent than do simple spans because complex spans require retrieval of items that have been displaced from primary memory due to the processing component of these tasks. Items in simple spans will also be displaced from primary memory but only after primary memory has become overloaded.

An automated version of the operation span task

We present an easy-to-administer and automated version of a popular working memory (WM) capacity task (operation span; Ospan) that is mouse driven, scores itself, and requires little intervention on the part of the experimenter. It is shown that this version of Ospan correlates well with other measures of WM capacity and has both good internal consistency (alpha = .78) and test-retest reliability (.83). In addition, the automated version of Ospan (Aospan) was shown to load on the same factor as two other WM measures. This WM capacity factor correlated with a factor composed of fluid abilities measures. The utility of the Aospan was further demonstrated by analyzing response times (RTs) that indicated that RT measures obtained in the task accounted for additional variance in predicting fluid abilities. Our results suggest that Aospan is a reliable and valid indicator of WM capacity that can be applied to a wide array of research domains.

Gc and Gf are both valid intelligence factors: Commentary on Robinson (2005)

We examine objections raised by Robinson (2005) to arguments in Ashton, Lee, and Vernon (2001), with reference to three methods we suggested for comparing the extent to which fluid (Gf) and crystallized (Gc) abilities represent “intelligence”. We suggest that results of analyses using these methods do not support the arguments that “Gc is the true intelligence or IQ factor” ( Robinson, 1999, p. 727) or that traditional measures of Gf, such as Raven’s Matrices or Block Design, “are certainly not good measures of intelligence” ( Robinson, 1999, p. 732). Instead, these results show that measures of crystallized and fluid abilities show similar relations with various intelligence criteria. In addition, we note that the factor analyses by Robinson (1999) tended to separate IQ scores from fluid ability subtests, by using age-adjusted IQ scores in a sample in which fluid ability was strongly negatively correlated with age, and by using an IQ score based on all ability subtests except one fluid ability subtest. We discuss the issue of crystallized bias in the Wechsler test batteries, and the relations of fluid and crystallized abilities with age and with biological markers of intelligence.

Age, Ability, and the Role of Prior Knowledge on the Acquisition of New Domain Knowledge: Promising Results in a Real-World Learning Environment.

Prior knowledge, fluid intelligence (Gf), and crystallized intelligence (Gc) were investigated as predictors of learning new information about cardiovascular disease and xerography with a sample of 199 adults (19 to 68 years). The learning environment included a laboratory multimedia presentation (high-constraint-maximal effort), and a self-directed at-home study component (low-constraint-typical performance). Results indicated that prior knowledge and ability were important predictors of knowledge acquisition for learning. Gc was directly related to learning from the video for both domains. Because the trajectory of Gc stays relatively stable throughout the life span, these findings provide a more optimistic perspective on the relationship between aging and learning than that offered by theories that focus on the role of fluid abilities in learning.