Placing inspection time, reaction time, and perceptual speed in the broader context of cognitive ability: The VPR model in the Lothian Birth Cohort 1936

The idea that information processing speed is related to cognitive ability has a long history. Much evidence has been amassed in its support, with respect to both individual differences in general intelligence and developmental trajectories. Two so-called elementary cognitive tasks, reaction time and inspection time, have been used to compile this evidence, but most studies have used either one or the other. Relations between speed and fluid intelligence have tended to be stronger than those between speed and crystallized intelligence, but studies testing this have confounded verbal abilities with crystallized intelligence and spatial/perceptual abilities with fluid intelligence. Questions have also been raised regarding whether speed contributes directly to general intelligence or to more specific cognitive abilities to which general intelligence also contributes. We used 18 ability and speed measures in the Lothian Birth Cohort 1936, assessed at approximately age 70, to construct alternative versions of the Verbal-Perceptual-Image Rotation (Johnson & Bouchard, 2005a) model of cognitive ability to test different hypotheses regarding these issues. Though differences in the extents to which our models fit the data were relatively small, they suggested that reaction and inspection time tasks were comparable indicators of information processing speed with respect to general intelligence, that verbal and spatial abilities were similarly related to information processing speed, and that spatial, verbal, and perceptual speed abilities were more directly related to information processing speed than was general intelligence. We discuss the theoretical implications of these results.     

Single tests,competing tasks and their relationship to the broad factors of intelligence

This paper presents the results of three studies in which scores obtained on single and competing tests were correlated with the composites representing fluid intelligence, crystallized intelligence, and the short-term acquisition and retrieval function. The results indicate that competing tasks have higher correlations with intelligence than single tests. Since in two studies of this paper no decrements in performance were observed on the competing as compared with the single task, the concept of limited central processing capacity cannot account for individual differences in performance of these cognitive tasks. It is suggested that the concept of efficient processing of information, perhaps efficient encoding, may be the basis for individual differences in cognitive abilities.     

工作记忆训练提升幼儿流体智力表现

目前已有许多研究证据表明, 工作记忆训练能提高成人、儿童的流体智力成绩, 然而这种训练是否能够提高幼儿的流体智力表现, 更为重要的是, 如果训练确有成效, 那么这种训练效果能否长期保持？为此, 本研究选择了幼儿园4~5岁幼儿进行工作记忆训练任务, 考察工作记忆训练对流体智力的提升及保持效应。实验中设立3个组：实验组、控制1组和控制2组。实验组采用单个空间n-back的工作记忆游戏程序进行训练, 控制1组采用“水果忍者”的游戏程序进行训练, 两组进行游戏训练的时间均为14天, 每天15 min; 控制2组不进行任何训练。结果发现, 训练后实验组幼儿被试的流体智力成绩明显优于两个控制组, 在6个月后再进行测试, 这种优势仍然保持。本研究结果表明, n-back工作记忆训练可以提高幼儿的流体智力成绩, 并且这种训练效果具有持续的稳定性。     

The Getting of Wisdom: Fluid Intelligence Does Not Drive Knowledge Acquisition

The investment hypothesis proposes that fluid intelligence drives the accumulation of crystallized intelligence, such that crystallized intelligence increases more substantially in individuals with high rather than low fluid intelligence. However, most investigations have been conducted on adolescent cohorts or in two-wave data sets. There are few longitudinal representative studies with which to observe the growth of intelligence in young adulthood. A large community representative sample of 20- to 24-year-olds was recruited in 1999 and followed in 2003 and 2007. The Spot-the-Word Test Version A, a lexical decision task, was used to assess crystallized intelligence. The Symbol–Digit Modalities Test, a test of perceptual speed, was used as a measure of fluid intelligence. Latent growth models were used to examine whether growth in fluid intelligence drives the acquisition of crystallized intelligence. Fluid and crystallized intelligence are coupled; crystallized intelligence accrues in the 20s, but the rate of increase of crystallized intelligence is not associated with the level of fluid intelligence. Although young adulthood is associated with “the getting of wisdom,” accelerated development of crystallized intelligence in those with high fluid intelligence was not observed. Hence, no support was found for the investment hypothesis.     

Can fluid intelligence be reduced to ‘simple’ short-term storage?

Much is written regarding the associations between human intelligence and cognition. However, it is unusual to find comprehensive studies. Here twenty four measures tapping eight cognitive abilities and skills are considered for assessing a sample of one hundred and eighty five young adults. The simultaneous relationships among fluid, crystallized, and spatial intelligence, along with short-term memory, working memory capacity, executive updating, attention, and processing speed are analyzed using a latent-variable approach. The key findings show that (a) short-term storage, working memory, and updating are hardly distinguishable, and (b) fluid intelligence is near-perfectly correlated with these three cognitive functions. It is concluded that this nuclear intelligence component can be largely identified with basic and general short-term storage processes, namely, encoding, maintenance, and retrieval.     

Ability factors and cognitive processes

Several measures of the speed of information processing were related to ability factors derived from the Cattell-Horn theory of fluid and crystallized intelligence. Ninety-one college students took a battery of paper and pencil tests designed to measure four ability factors: fluid intelligence (Gf), crystallized intelligence (Gc), spatial visualization (Gv), and clerical perceptual speed (CPS). They also performed paper and pencil and computerized versions of three information processing tasks: mental rotations, letter matching, and sentence verification. Correlations among the ability measures, among the information processing measures, and between the two domains were analyzed using confirmatory factor analysis. The four ability factors were found to be largely independent in this college population. Speed of letter-matching and sentence verification were highly correlated, but neither was related to speed of mental rotation. Mental rotation speed was strongly correlated with Gv; letter matching speed was correlated with CPS; and sentence verification speed was correlated with both Gc and CPS.     

Superior fluid intelligence in children with Asperger's disorder

Asperger's disorder is one of autistic spectrum disorders; sharing clinical features with autism, but without developmental delay in language acquisition. There have been some studies of intellectual functioning in autism so far, but very few in Asperger's disorder. In the present study, we investigated abstract reasoning ability, whose form of intelligence has been labeled fluid intelligence in the theory of Cattell [Cattell, R. B. (1963). Theory of fluid and crystallized intelligence: A critical experiment. Journal of Educational Psychology, 54, 1-22.], in children with Asperger's disorder. A test of fluid intelligence, the Raven's Standard Progressive Matrices Test, was administered to 17 children with Asperger's disorder and 17 age-, gender-, and FIQ-matched normal children. The results showed that children with Asperger's disorder outperformed on the test of fluid reasoning than typically developing children. We suggest that individuals with Asperger's disorder have higher fluid reasoning ability than normal individuals, highlighting superior fluid intelligence.     

Intellectual growth in children as a function of domain specific and domain general working memory subgroups

This study examined whether children's growth on measures of fluid (Raven Colored Progressive Matrices) and crystallized (reading and math achievement) intelligence was attributable to domain-specific or domain-general functions of working memory (WM). A sample of 290 elementary school children was tested on measures of intelligence across three testing waves. Two methods, a hierarchical factor model predicting latent growth and a double dissociation design comparing children divided into high and low performers, tested whether general and/or specific components accounted for performance on intelligence measures. A general domain model for the total sample provided the best fit for latent growth on all measures. Further, the lack of a significant WM subgroup × domain interaction suggested that a general WM system underlies the individual differences on measures of fluid and crystallized intelligence. Overall, the findings support a domain-general view of WM capacity on intelligence measures in children, but also suggest that domain specific storage systems may come into play on isolated measures.     

Do Smarter People Employ Better Decision Strategies? The Influence of Intelligence on Adaptive Use of the Recognition Heuristic

Within the adaptive toolbox approach, it has repeatedly been shown that, on average, people tend to adapt their decision strategies to the decision context. Building upon these results, we investigated whether individuals systematically differ in their ability to successfully adapt to the situation when applying the fast‐and‐frugal recognition heuristic (RH). In decisions between recognized and unrecognized choice objects, individuals can base their choices solely on recognition, as predicted by the RH, or they can use further knowledge retrieved from memory. Since intelligence has been conceived as the ability to successfully adapt to different situations, we expected intelligence to influence the degree of adaptive use of the RH. To test this hypothesis, we first re‐analyzed data that referred to a decision domain for which RH‐use is known to perform well. As expected, individual RH‐use increased with general intelligence. Next, we designed an experiment addressing individual RH‐use in two new decision domains, one domain for which RH‐use was less effective than knowledge‐use and another domain for which both strategies were about equally effective. In addition, we tested whether fluid or crystallized intelligence best predicts adaptive use of the RH. RH‐use was found to decrease with fluid but not crystallized intelligence when RH‐use was less effective than use of further knowledge. In contrast, there was no significant association between either type of intelligence and RH‐use when none of the two strategies was optimal. We conclude that adaptive use versus non‐use of the RH is moderated by fluid intelligence. Copyright © 2017 John Wiley & Sons, Ltd.     

Aging, attention, and intelligence

The aims of this study were (a) to find out if attentional ability factors that are separate from the well-established ability factors (e.g., fluid intelligence, crystallized intelligence, and short-term acquisition and retrieval function) can be identified, and (b) to establish, through the use of part correlations, whether attentional abilities play a role in the changes in fluid and crystallized intelligence that occur with increasing age. A battery of 36 tests (19 psychometric tests and 17 measures of attentional processes) were given to 100 people. 20 of whom were in each age decade between 20 and 70. Results indicated that three attentional factors--Search, Concentration, and Attentional Flexibility--exist at the primary-ability level and that all three define fluid intelligence at the second-order level. Results also indicate that the decline in fluid intelligence with increasing age disappears if attentional factors are parted-out. Similarly, the increase in crystallized intelligence with increasing age becomes even greater if one controls for attentional processes. I conclude that changes in attentional processes play an important part in changes in human intelligence with age.     

Is speed of information processing related to fluid or to crystallized intelligence?

Speed of information processing was examined in relation to the theory of fluid and crystallized intelligence. Sixty sixth grade children completed the Standard Progressive Matrices test and the Mill Hill Vocabulary scale, both untimed, as measures of fluid and crystallized intelligence, and three RT tasks: Memory Scanning, Picture Identification, and Sentence-Picture Comparison. As predicted, RT parameters, with the exception of slope on two tasks, were negatively correlated with scores on both tests. There were no consistent differences between the two tests in the size of correlations with RT, and partial correlations, eliminating the effects of fluid and crystallized intelligence respectively, failed to support any causal relationship between fluid and crystallized intelligence in either direction. Some limitations of the research, specifically in the possible effect of error rates on the speed-intelligence relationship, and in the application to individuals of task parameters derived from group performance, are noted.     

Sensory Discrimination,Working Memory and Intelligence in 9‐Year‐Old and 11‐Year‐Old Children

More than a century ago, Galton and Spearman suggested that there was a functional relationship between sensory discrimination ability and intelligence. Studies have since been able to confirm a close relationship between general discrimination ability (GDA) and IQ. The aim of the present study was to assess whether this strong relationship between GDA and IQ could be due to working memory (WM) demands of GDA tasks. A sample of 140 children (seventy 9‐year‐olds and seventy 11‐year‐olds) was studied. Results showed that there was a significant overlap between WM, GDA and fluid intelligence. Furthermore, results also revealed that WM could not explain the relationship between GDA and fluid intelligence as such, but that it acted as a bottleneck of information processing, limiting the influence of GDA on the prediction of fluid intelligence. Specifically, GDA's influence on the prediction of intelligence was only visible when WM capacity was above a certain level. Copyright © 2013 John Wiley & Sons, Ltd.     

On intelligence II: A neo-Spearman model to replace Cattell's theory of fluid and crystallized intelligence

While many empirical studies now support second-order simple structure factor analytic distinctions consistent with Cattell's theory of fluid and crystallized intelligence, the hierarchical order analyses carried out in the present study show that these factors are structured so as to suggest a neo-Spearman hierarchical model where fluid intelligence is equivalent to a general intelligence factor and broad group factors of verbal-educational knowledge, speediness, and visualization appear. The two models have different implications regarding the status of the fluid and crystallized "intelligence" factors and the relationship between them.     

Adaptive n-back training does not improve fluid intelligence at the construct level: Gains on individual tests suggest that training may enhance visuospatial processing

Short-term adaptive cognitive training based on the n-back task is reported to increase scores on individual ability tests, but the key question of whether such increases generalize to the intelligence construct is not clear. Here we evaluate fluid/abstract intelligence (Gf), crystallized/verbal intelligence (Gc), working memory capacity (WMC), and attention control (ATT) using diverse measures, with equivalent versions, for estimating any changes at the construct level after training. Beginning with a sample of 169 participants, two groups of twenty-eight women each were selected and matched for their general cognitive ability scores and demographic variables. Under strict supervision in the laboratory, the training group completed an intensive adaptive training program based on the n-back task (visual, auditory, and dual versions) across twenty-four sessions distributed over twelve weeks. Results showed that this group had the expected systematic improvements in n-back performance over time; this performance systematically correlated across sessions with Gf, Gc, and WMC, but not with ATT. However, the main finding showed no significant changes in the assessed psychological constructs for the training group as compared with the control group. Nevertheless, post-hoc analyses suggested that specific tests and tasks tapping visuospatial processing might be sensitive to training.     

Which is the real intelligence? A reply to Robinson (1999)

Robinson's ([Robinson, D.L. (1999). The ‘IQ’ factor: implications for intelligence theory and measurement. Personality and Individual Differences, 27, 715–735]) arguments that crystallized intelligence represents the “one valid intelligence factor” are disputed. It is argued that Robinson seriously underestimated the relevance of fluid abilities to “intelligence”, by using an inappropriate criterion for assessing the intelligence-saturation of cognitive ability variables. The relevance of fluid and crystallized abilities to popular, psychometric, and biological conceptions of intelligence is discussed, and the issue of age-related changes in fluid and crystallized intelligence is also addressed.     

High intelligence prevents the negative impact of anxiety on working memory

Using a large sample and the confirmatory factor analysis, the study investigated the relationships between anxiety, working memory (WM) and (fluid) intelligence. The study showed that the negative impact of anxiety on WM functioning diminishes with increasing intelligence, and that anxiety can significantly affect WM only in people below average intelligence. This effect could not be fully explained by the sheer differences in WM capacity (WMC), suggesting the importance of higher-level cognition in coping with anxiety. Although intelligence moderated the impact of anxiety on WM, it was only weakly related to anxiety. In contrast to previous studies, anxiety explained the substantial amount of WMC variance (17.8%) in less intelligent participants, but none of the variance in more intelligent ones. These results can be explained in terms of either increased motivation of intelligent but anxious people to cope with a WM task, or their ability to compensate decrements in WM.     

Modeling differentiation of cognitive abilities within the higher-order factor model using moderated factor analysis

Receptive foreign language proficiency is usually measured with reading and listening comprehension tasks. A novel approach to assess such proficiencies – viewing comprehension – is based on the presentation of short instructional videos followed by one or more comprehension questions concerning the preceding video stimulus. In order to evaluate a newly developed viewing comprehension test 485 German high school students completed reading, listening, and viewing comprehension tests, all measuring the receptive proficiency in English as a foreign language. Fluid and crystallized intelligence were measured as predictors of performance. Relative to traditional comprehension tasks, the viewing comprehension task has similar psychometric qualities. The three comprehension tests are very highly but not perfectly correlated with each other. Relations with fluid and crystallized intelligence show systematic differences between the three comprehension tasks. The high overlap between foreign language comprehension measures and between crystallized intelligence and language comprehension ability can be taken as support for a uni-dimensional interpretation. Implications for the assessment of language proficiency are discussed.     

The Neural Architecture of General Knowledge

Cognitive performance varies widely between individuals and is highly influenced by structural and functional properties of the brain. In the past, neuroscientific research was principally concerned with fluid intelligence, while neglecting its equally important counterpart crystallized intelligence. Crystallized intelligence is defined as the depth and breadth of knowledge and skills that are valued by one's culture. The accumulation of crystallized intelligence is guided by information storage capacities and is likely to be reflected in an individual's level of general knowledge. In spite of the significant role general knowledge plays for everyday life, its neural foundation largely remains unknown. In a large sample of 324 healthy individuals, we used standard magnetic resonance imaging along with functional magnetic resonance imaging and diffusion tensor imaging to examine different estimates of brain volume and brain network connectivity and assessed their predictive power with regard to both general knowledge and fluid intelligence. Our results demonstrate that an individual's level of general knowledge is associated with structural brain network connectivity beyond any confounding effects exerted by age or sex. Moreover, we found fluid intelligence to be best predicted by cortex volume in male subjects and functional network connectivity in female subjects. Combined, these findings potentially indicate different neural architectures for information storage and information processing. © 2019 European Association of Personality Psychology     

Racial differences in intelligence: The importance of the executive system

The race-IQ controversy arose at a time when psychometric views of intelligence dominated. Little attention was paid to more process-oriented models in spite of the fact they provide alternative perspectives on the causes of individual differences in problem-solving. We hypothesized that much of the IQ spread commonly observed between black and white children can be attributed to differences in components of their executive systems, including the knowledge base, control processes, and metacognitive states. To test this possibility, black and white children who differed significantly on fluid and crystallized intelligence were tested on multiple tasks reflecting components of the executive systems as well as on perceptual efficiency tasks. Striking group differences were observed in metamemory, stragegy use, and general knowledge, but few reliable differences were found in perceptual efficiency. Regression analyses showed that different factors predicted fluid and crystallized intelligence, with metamemory predicting the latter but not the former. An implication of these findings has potential educational significance: training directed at executive skills, introduce at an early age, might elevate learning and problem-solving skills in black children, thereby reducing racial differences in crystallized intelligence.     

个体差异对工作记忆训练迁移效果的调节

本研究考察了流体智力基线水平对工作记忆训练迁移效果的影响。采用前后测设计,以视觉和听觉双任务n-back作为工作记忆训练任务,对训练组进行为期一个月的训练;积极对照组采用阅读任务进行训练。结果发现积极控制组的流体智力水平在基线与后测之间无显著变化;而训练组流体智力水平在后测时与基线相比有显著提高,且工作记忆训练提升量越大的个体其流体智力改善越大。说明认知训练有效迁移到了流体智力水平的改善上。我们还发现流体智力基线水平调节了工作记忆训练对流体智力水平的迁移,即工作记忆训练提升量越大,流体智力改善值越大,对于那些流体智力基线水平较高的人来说,工作记忆训练对流体智力改善的效果更大。流体智力基线水平、工作记忆训练提升量及两者的乘积共同影响了流体智力改善值。这一结果表明个体差异如流体智力基线水平可以调节工作记忆训练对流体智力水平的迁移。