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.     

Using the process dissociation procedure to estimate recollection and familiarity in working memory: An experimental and individual differences investigation

Numerous studies have found that working memory capacity and perceptual speed predict variation in fluid intelligence. Within the cognitive ageing literature, perceptual speed accounts for substantial ageing variance in working memory capacity and fluid intelligence. However, within young adults, the interrelationships among these three abilities are less clear. The current work investigated these relationships via confirmatory factor analyses and structural equation modelling using tasks with verbal, spatial, and numerical content. The results indicate that working memory capacity and perceptual speed were not related in a large, cognitively diverse sample of young adults. However, both working memory capacity and perceptual speed accounted for unique variance in fluid intelligence. The results are discussed in relation to previous research with young and older adults.     

The structure of working memory and how it relates to intelligence in children

This study explored the structure of working memory, and its relationship with intelligence in 176 typically-developing children in the 4th and 5th grades at school. Different measures of working memory (WM), and intelligence (g) were administered. Confirmatory factor analyses showed that WM involves an attentional control system and storage aspects that rely on domain-specific verbal (STM-V) and visuospatial (STM-VS) resources. The structural equation models showed that WM predicts a large portion (66%) of the variance in g, confirming that the two constructs are separable but closely related in young children. Findings also showed that only WM and STM-VS are significantly related to g, while the contribution of STM-V is moderate. Theoretical implications for the relationship between WM and g are discussed.     

Working memory resources in young children with mathematical difficulties

Kyttälä, M., Aunio, P. & Hautamäki, J. (2010). Working memory resources in young children with mathematical difficulties. Scandinavian Journal of Psychology, 51 , 1–15.
Working memory (WM) ( Baddeley, 1986, 1997 ) is argued to be one of the most important cognitive resources underlying mathematical competence ( Geary, 2004 ). Research has established close links between WM deficits and mathematical difficulties. This study investigated the possible deficits in WM, language and fluid intelligence that seem to characterize 4- to 6-year-old children with poor early mathematical skills before formal mathematics education. Children with early mathematical difficulties showed poor performance in both verbal and visuospatial WM tasks as well as on language tests and a fluid intelligence test indicating a thoroughly lower cognitive base. Poor WM performance was not moderated by fluid intelligence, but the extent of WM deficits was related to language skills. The educational implications are discussed.     

The roles of different executive functioning skills in young children’s mental computation and applied mathematical problem-solving

This study investigated the relationships of four executive functioning skills (including verbal working memory, spatial working memory, inhibitory control, and cognitive flexibility) with young children’s mental computation and applied mathematical problem-solving. Two hundred and twenty-five Chinese kindergarteners were tested with a battery of general cognitive, executive functioning and mathematics skills. Results showed that when children’s age, gender, non-verbal intelligence, and listening comprehension skills were controlled, verbal working memory and cognitive flexibility were significant correlates of mental computation, whereas verbal working memory, spatial working memory, and cognitive flexibility were significant correlates of applied mathematical problem-solving. Inhibitory control was not significantly associated with the two domains of mathematics under investigation. The findings highlight the differential roles of different executive functioning skills in early mathematical skills and offer practical implication for helping young children in learning complex mathematical skills.     

加工速度、工作记忆与液态智力发展的关系

有关儿童液态智力 (fluid intelligence) 发展的年龄特征早已有了较明确的一致性结论。然而,儿童液态智力发展的机制问题到现在仍知之甚少。早期零星的研究观察到,随着儿童年龄的增长,其信息加工速度变快,工作记忆能力和液态智力亦提高。由此可推测,对儿童液态智力与加工速度、工作记忆能力关系的考察有助于阐明儿童液态智力发展的机制问题。 近10多年已有不少研究分别探讨了液态智力与加工速度、液态智力与工作记忆的关系,并已开始同时探讨液态智力与加工速度和工作记忆的关系。但令人惊讶的是,有关儿童液态智力发展与加工速度、工作记忆关系问题的综合探讨几成空白,到目前为止,仅有极少量的研究 (Fry 和Hale, 1996; Miller和Vernon, 1996) 探讨了这一问题,其中Fry 和Hale (1996) 还提出了一个模型 (the developmental cascade model) 试图解释儿童液态智力发展的机制,随后Fry 和Hale (2000)进一步阐明并坚持了这一观点。Fry 和Hale的观点是,儿童液态智力的发展取决于儿童工作记忆能力的发展,而工作记忆能力的发展又进一步取决于儿童信息加工速度能力的发展。这就是说,加工速度和工作记忆是儿童液态智力发展的两个关键因素,其中加工速度又是第一作用因素。Fry 和Hale (1996, 2000) 提出了她们的观点后,后续研究在国际上仍十分少见。但来自于发展领域之外的研究似乎不支持Fry 和Hale (1996, 2000)的观点。研究发现(Conway et al., 2002),仅工作记忆能很好预测液态智力的变化,而加工速度不能很好预测液态智力的变化。 该研究从南京市中小学随机选取了243名10到18岁的健康儿童（男生127名,女生116名）。所有被试共完成7项任务,包括2项液态智力任务测试（瑞文标准推理测验和卡特尔文化公平智力测验,以原始分作为数据分析指标）、3项加工速度任务测试（数字抄写、字母串比较和符号串比较）、2项工作记忆任务（数字工作记忆和视空间工作记忆）。验证性因素分析发现这7项任务所测量的正是液态智力、加工速度和工作记忆这3个因子,且这3个因子间存在显著的相关。但随后的结构方程模型分析表明,从工作记忆到液态智力间存在显著路径,但从加工速度到液态智力并不存在显著路径,工作记忆几乎可完全解释儿童液态智力的发展变化（85.4%）,且可以解释81.6%的加工速度的发展变化量。仅当不考虑工作记忆这一因素时,加工速度才能解释50%的液态智力的发展变化。这表明,工作记忆是儿童液态智力发展的基础,而加工速度则不是。这一结果在以三个变量的平均标准分数为基础所进行的层级回归分析 (hierarchical regression analyses)中亦得到了证实。 总体上,该研究并不支持Fry 和Hale (1996, 2000)的观点。工作记忆是儿童液态智力发展的关键因素,而加工速度则不是。加工速度与液态智力存在显著相关,其原因可能在于,加工速度反映的是儿童液态智力的同一年龄内个体差异而不是年龄间差异（即发展性变化）。本研究同时对工作记忆之所以是儿童液态智力发展的基础的可能原因进行了讨论。     

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 role of working memory and updating in Coloured Raven Matrices performance in typically developing children

A large body of evidence indicates that working memory correlates with performance on fluid intelligence tasks such as Raven's tests. However, light still needs to be shed on which particular aspects of working memory might be most critically related to fluid intelligence, and whether working memory updating—which appears crucial to intellectual functioning—has a prominent role. To address these issues more closely, our study presented participants (aged 5–11 years) with the Raven's Coloured Progressive Matrices, an updating task, and a battery of working memory tasks. Our findings confirm that working memory indeed plays an important part in explaining fluid intelligence, in particular that updating information in working memory is critical to fluid intelligence in the context of development.     

Memory span and general intelligence: A latent-variable approach

There are several studies showing that working memory and intelligence are strongly related. However, working memory tasks require simultaneous processing and storage, so the causes of their relationship with intelligence are currently a matter of discussion. The present study examined the simultaneous relationships among short-term memory (STM), working memory (WM), and general intelligence (g). Two hundred and eight participants performed six verbal, quantitative, and spatial STM tasks, six verbal, quantitative, and spatial WM tasks, and eight tests measuring fluid, crystallized, spatial, and quantitative intelligence. Especial care is taken to avoid misrepresenting the relations among the constructs being studied because of specific task variance. Structural equation modelling (SEM) results revealed that (a) WM and g are (almost) isomorphic constructs, (b) the isomorphism vanishes when the storage component of WM is partialed out, and (c) STM and WM (with its storage component partialed out) predict g.     

A dissociation between the sense of familiarity and access to semantic information concerning familiar people

In the current study we examined the relationship between working memory capacity, inhibition/susceptibility to interference and fluid intelligence, measured by the Raven's Progressive Matrices (PM38), comparing groups of young (aged 18–35), young-old (aged 65–74), and old-old (aged 75–86) participants. Groups were administered two working memory tasks tapping into different mechanisms involved in working memory. The ability to control for irrelevant information was measured both considering memory errors (intrusion errors) in a working memory task and an index of susceptibility to interference obtained with a variant of the Brown-Peterson task. Regression analyses showed that the classical working memory measure was the most potent predictors of the Raven's score. Susceptibility to interference and intrusions errors contributed, but to a lower extent, to the Raven explained variance. These results confirm that working memory shares cognitive aspects with the fluid intelligence measure considered, whereas the role of inhibition to Raven scores is still in need of better evidence.     

Working memory in multilingual children: Is there a bilingual effect?

This research investigates whether early childhood bilingualism affects working memory performance in 6- to 8-year-olds, followed over a longitudinal period of 3 years. The study tests the hypothesis that bilinguals might exhibit more efficient working memory abilities than monolinguals, potentially via the opportunity a bilingual environment provides to train cognitive control by combating interference and intrusions from the non-target language. A total of 44 bilingual and monolingual children, matched on age, sex, and socioeconomic status, completed assessments of working memory (simple span and complex span tasks), fluid intelligence, and language (vocabulary and syntax). The data showed that the monolinguals performed significantly better on the language measures across the years, whereas no language group effect emerged on the working memory and fluid intelligence tasks after verbal abilities were considered. The study suggests that the need to manage several language systems in the bilingual mind has an impact on children's language skills while having little effects on the development of working memory.     

The broad factor of working memory is virtually isomorphic to fluid intelligence tested under time pressure

How much overall variance in fluid intelligence (Gf) can be predicted by four working memory (WM) functions: storage capacity, attention control, relational integration, and updating was investigated under time pressured Gf testing. Confirmatory factor analysis indicated that the broad WM factor, which was subsumed by these four WM functions, shared 83.4% of variance with Gf tested under pressure, whereas a reanalysis of previous data with the same model showed that only 58.2% variance was shared with virtually untimed Gf tests. Moreover, in timed Gf tests, only the easiest, early items contributed to the WM-Gf correlation, whereas in untimed tests also the hardest, late items were linked with Gf. These results suggest that the measurement of “fast” intelligence primarily taps the functions of WM, whereas “slow(er)” intelligence depends also on some other cognitive processes beyond WM.     

Children's working memory: Its structure and relationship to fluid intelligence

Working memory (WM) has been predominantly studied in adults. The insights provided by these studies have led to the development of competing theories on the structure of WM and conflicting conclusions on how strongly WM components are related to higher order thinking skills such as fluid intelligence. However, it remains unclear whether and to what extent the theories and findings derived from adult data generalize to children. The purpose of the present study is therefore to investigate children's WM (N = 161), who attended classes at the end of kindergarten in Luxembourg. Specifically, we examine different structural models of WM and how its components, as defined in these models, are related to fluid intelligence. Our results indicate that short-term storage capacity primarily explains the relationship between WM and fluid intelligence. Based on these observations we discuss the theoretical and methodological issues that arise when children's WM is investigated.     

A structural analysis of working memory and related cognitive skills in young children

The aim of this study was to investigate the functional organisation of working memory and related cognitive abilities in young children. A sample of 633 children aged between 4 and 6 years were tested on measures of verbal short-term memory, complex memory span, sentence repetition, phonological awareness, and nonverbal ability. The measurement model that provided the best fit of the data incorporates constructs that correspond to the central executive, phonological loop, and episodic buffer subcomponents of working memory, plus distinct but associated constructs associated with phonological awareness and nonverbal ability.     

Differences in mathematical reasoning between typically achieving and gifted children

Mathematical giftedness refers to mastery in a specific mathematical domain at an earlier than expected age. The present study examined which cognitive processes accounted for differences in mathematical reasoning between gifted children (MRG) and their typically achieving peers (TA). Naming speed, phonological awareness, short-term memory, executive functioning, and working memory were examined in 51 children aged approximately 7 years. A series of stepwise regression models, using a contrast variable to capture differences in mathematical reasoning between MRG and TA children, were created to examine which cognitive domains accounted for differences in mathematical reasoning. Short-term memory (r²?=?.08) and visual-spatial working memory (r²?=?.39) emerged as the only cognitive predictors within a model that included gender, age, and fluid intelligence. This model captured all of the variance distinguishing mathematics reasoning between MRG and TA children, explaining an overall contribution of 70% of the variance in mathematical reasoning.     

幼儿复述能力的发展及其与言语工作记忆的关系

采用语音呈现、无图片辅助的复述任务，探查5～6岁幼儿故事复述能力的发展特点及其与工作记忆的关系。结果发现，幼儿复述能力在学前期存在明显的发展变化，6岁幼儿宏观结构的得分及微观结构中的叙事总词汇数、复句占T单元比率、连词使用总数等均显著好于5岁幼儿；幼儿的复述能力表现出性别差异；工作记忆与复述的宏观结构和微观结构的不同指标之间均表现出显著相关，并对幼儿复述能力的发展具有独立贡献。结果表明，言语工作记忆是与幼儿复述能力相关的重要认知因素。     

How similar are fluid cognition and general intelligence? A developmental neuroscience perspective on fluid cognition as an aspect of human cognitive ability

This target article considers the relation of fluid cognitive functioning to general intelligence. A neurobiological model differentiating working memory/executive function cognitive processes of the prefrontal cortex from aspects of psychometrically defined general intelligence is presented. Work examining the rise in mean intelligence-test performance between normative cohorts, the neuropsychology and neuroscience of cognitive function in typically and atypically developing human populations, and stress, brain development, and corticolimbic connectivity in human and nonhuman animal models is reviewed and found to provide evidence of mechanisms through which early experience affects the development of an aspect of cognition closely related to, but distinct from, general intelligence. Particular emphasis is placed on the role of emotion in fluid cognition and on research indicating fluid cognitive deficits associated with early hippocampal pathology and with dysregulation of the hypothalamic-pituitary-adrenal axis stress-response system. Findings are seen to be consistent with the idea of an independent fluid cognitive construct and to assist with the interpretation of findings from the study of early compensatory education for children facing psychosocial adversity and from behavior genetic research on intelligence. It is concluded that ongoing development of neurobiologically grounded measures of fluid cognitive skills appropriate for young children will play a key role in understanding early mental development and the adaptive success to which it is related, particularly for young children facing social and economic disadvantage. Specifically, in the evaluation of the efficacy of compensatory education efforts such as Head Start and the readiness for school of children from diverse backgrounds, it is important to distinguish fluid cognition from psychometrically defined general 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。     

抑制控制与高级认知功能的关系

近年来抑制控制与高级认知功能关系的研究受到了越来越多的重视。大量实证研究表明, 抑制控制是解释工作记忆、阅读理解、液态智力等高级认知功能个体差异的一个重要机制。脑成像研究表明, 抑制控制与工作记忆和液态智力等高级认知功能都激活了前额叶和顶叶等共同脑区。同时, 认知发展和认知老化, 以及认知干预领域的研究都一致表明, 抑制控制与高级认知功能关系密切。未来研究应注意抑制控制的定义和测量问题, 以及脑机制和训练干预等方面的问题。     

Working Memory Capacity as Executive Attention

Performance on measures of working memory (WM) capacity predicts performance on a wide range of real-world cognitive tasks. I review the idea that WM capacity (a) is separable from short-term memory, (b) is an important component of general fluid intelligence, and (c) represents a domain-free limitation in ability to control attention. Studies show that individual differences in WM capacity are reflected in performance on antisaccade, Stroop, and dichotic-listening tasks. WM capacity, or executive attention, is most important under conditions in which interference leads to retrieval of response tendencies that conflict with the current task.