Fluid intelligence as a predictor of learning: A longitudinal multilevel approach applied to math

The association between fluid intelligence and inter-individual differences was investigated using multilevel growth curve modeling applied to data measuring intra-individual improvement on math achievement tests. A sample of 166 students (88 boys and 78 girls), ranging in age from 11 to 14 (M = 12.3, SD = 0.64), was tested. These individuals took four math achievement tests, which were vertically equated via Item Response Theory, at the beginning and end of the seventh and eighth grade. The cognitive abilities studied were Numerical Reasoning, Abstract Reasoning, Verbal Reasoning, and Spatial Reasoning (as measured by the Differential Reasoning Test). The general cognitive factor was significantly associated with the parameters of initial level (intercept) and rate of change (slope). A high level of intelligence was associated with higher initial scores, as well as a steeper rise in math scores across the two years.     

Decay of iconic memory traces is related to psychometric intelligence: A fixed-links modeling approach

Several memory processes have been examined regarding their relation to psychometric intelligence with the exception of sensory memory. This study examined the relation between decay of iconic memory traces, measured with a partial-report task, and psychometric intelligence, assessed with the Berlin Intelligence Structure test, in 111 participants. Using a fixed-links modeling approach, the exponential decay of iconic memory traces was quantified and separated from the effects of (systematic variance due to) subsidiary processes unrelated to this decay. Higher psychometric intelligence was associated with slower decay of iconic memory traces even when the influence of selective and divided attention was controlled for. These findings provide first experimental evidence for a functional relationship between information processing in sensory memory and individual levels of psychometric intelligence. The use of fixed-links models is discussed with regard to delineating processes in a repeated-measures design.     

Training and changes in fluid and crystallized intelligence

In this study, the same battery of tests was administered three times: at the beginning of the experiment, at the end of training, and 1 year after the end of training. The control group was taught in the traditional way. The experimental group was given extensive training in creative problem solving over a 3-year period. The invariant factor structure model for multimode data (R. P. McDonald, 1984, in Research methods of multimode data analysis, New York: Praeger Scientific) was fitted, with LISREL, to both groups simultaneously. At the last testing session, the experimental group performed better than the control group on a majority of variables. Fluid intellectual abilities were somewhat more affected by training in creative problem solving than were crystallized abilities.     

Individual differences in spatial text processing: High spatial ability can compensate for spatial working memory interference

The present study investigates the relation between spatial ability and visuo-spatial and verbal working memory in spatial text processing. In two experiments, participants listened to a spatial text (Experiments 1 and 2) and a non-spatial text (Experiment 1), at the same time performing a spatial or a verbal concurrent task, or no secondary task. To understand how individuals who differ in spatial ability process spatial text during dual task performance, spatial individual differences were analyzed. The tasks administered were the Vandenberg and Kuse [Vandenberg, S. G., & Kuse, A. R. (1978). Mental rotation, a group test of three-dimensional spatial visualization. Perceptual and Motor Skills, 47, 599-604.] mental rotation test (MRT) and a reading comprehension task (RCT). Individuals with high (HMR) and low (LMR) mental rotation differed in MRT scores but had similar RCT performance. Results showed that the HMR group, in contrast with LMR counterparts, preserved good spatial text recall even when a spatial concurrent task was performed; however, Experiment 2 revealed a modification of spatial concurrent task performance in LMR as well in HMR group. Overall, results suggest that HMR individuals have more spatial resources than LMR individuals, allowing them to compensate for spatial working memory interference, but only to a limited extent, given that the processing of spatial information is still mediated by VSWM.     

Developmental trends for object and spatial working memory: a psychophysiological analysis

This study examined developmental trends in object and spatial working memory (WM) using heart rate (HR) to provide an index of covert cognitive processes. Participants in 4 age groups (6-7, 9-10, 11-12, 18-26, n=20 each) performed object and spatial WM tasks, in which each trial was followed by feedback. Spatial WM task performance reached adult levels before object WM task performance. The differential developmental trends for object and spatial WM found in this study are taken to suggest that these WM components are separable. Negative performance feedback elicited HR slowing that was more pronounced for adults than for children. The development of performance monitoring as indexed by covert HR slowing following performance feedback contributes to WM performance.     

Specific impairment in developmental reading disabilities: a working memory approach

Children with developmental reading disabilities (RD) frequently display impaired working memory functioning. However, research has been divergent regarding the characteristics of the deficit. Our investigation addressed this controversy by assessing Baddeley's working memory model as a whole rather than focusing on particular aspects of it, as has been done by much of the research to date. Participants included 20 children with RD and 20 typical readers between the ages of 9 and 13. The phonological loop, visual-spatial sketchpad, and central executive were assessed according to Baddeley's model. The results demonstrated that children with RD have an impaired phonological loop but intact visual-spatial sketchpad and central executive functioning as compared to controls. In terms of the phonological loop, the deficit appears to be specific to the phonological store. Furthermore, our research supports a relationship between phonological processing and phonological loop functioning.     

The working memory rating scale: A classroom-based behavioral assessment of working memory

The aim of the present study was to investigate the potential of the Working Memory Rating Scale (WMRS), an observer-based rating scale that reflects behavioral difficulties of children with poor working memory. The findings indicate good internal reliability and adequate psychometric properties for use as a screening tool by teachers. Higher (i.e., more problematic) teacher ratings on the WMRS were associated with lower memory scores on direct assessments of working memory skills, as measured by the Automated Working Memory Assessment (AWMA) and the WISC-IV Working Memory Index. The use of the WMRS will allow educators to draw on their expertise in the classroom for early detection of children with working memory failures.     

The existence and extent of spatial working memory ability in honeybees

Honeybees foraged from six locations, each of which was baited with sugar solution prior to each experimental trial. Under a variety of conditions, bees exhibited a small but reliable tendency to avoid revisits to locations that they had visited earlier during the experimental trial. These results replicate those of Brown and Demas (1994), who concluded that bees use working memory to discriminate previously visited locations from those not yet visited. The present experiments included procedures that allowed alternatives to this explanation to be more completely ruled out. The extent of spatial working memory performance exhibited by honeybees in these experiments appears to be limited by a process other than working memory capacity, perhaps the ability of bees to discriminate among several locations in close proximity to one another.     

Search behavior in cats and dogs: Interspecific differences in working memory and spatial cognition

Cats’ and dogs’ search behavior was compared in different problems where an object was visibly moved behind a screen that was then visibly moved to a new position. In Experiments 1 (cats) and 2 (dogs), one group was tested with identical screens and the other group was tested with dissimilar screens. Results showed that in both species, search behavior was based on processing of spatial information rather than on recognition of the visual features of the target screen. Cats and dogs were unable to find the object by inferring its invisible movement. They reached a high level of success only if there was direct perceptual evidence that the object could not be at its initial position. When the position change was indicated by an indirect cue, cats searched more at the object’s initial than final position, whereas dogs searched equally at both positions. Interspecific similarities and differences are interpreted in terms of the requirements for resetting working memory.     

Some factors underlying mathematical performance: The role of visuospatial working memory and non-verbal intelligence

Passive and active visuospatial working memory (VSWM) were investigated in relation to maths performance. The mental rotation task was employed as a measure of active VSWM whereas passive VSWM was investigated using a modified Corsi Blocks task and a matrix pattern task. The Raven Progressive Matrices Test measured fluid intelligence. A total of 128 students, aged 15–16, served as participants. Fluid intelligence and passive VSWM accounted for variance in overall maths performance. Active VSWM exhibited significant correlations with maths measures, but in a series of regression analyses most of its effect was observed to be mediated by fluid intelligence. Different subscores of mathematical skills (geometry, word problems, and mental arithmetic) were accounted for by fluid intelligence and different measures of VSWM. The educational implications of the results are discussed.     

Characteristics of pigeons’ spatial working memory in an open-field task

Although pigeons seem to require special training before they will display accurate spatial working memory in radial-arm mazes, they readily show accurate working memory for recently visited feeder locations in an open-field analog of the radial maze. In this task, pigeons forage among sites located on the floor of an open room, with no constraints on the path they take between sites. Experiment 1 suggested that pigeons’ working memory for recently visited sites is facilitated if they are permitted to develop a stable reference memory “map” of the location of the sites with respect to landmarks in the room: Pigeons for which the landmarks remained constant from day to day displayed more accurate working memory than did pigeons for which the landmarks were rearranged between daily trials. The second experiment investigated the durability of pigeons’ working memory, using a forced-choice procedure. Accuracy remained high for retention intervals of up to 32 min, but dropped significantly with a 2-h delay.     

Constructing domain-specific knowledge in kindergarten: Relations among knowledge,intelligence, and strategic performance

Thirty kindergarten children from two classrooms participated in a 3-week curricular unit on dinosaurs designed to teach taxonomic relations and distinguishing features aligned with 15 dinosaur species. Both domain-specific learning and strategic performance on a Twenty Questions game were assessed twice throughout the curriculum, as well as during a postcurriculum assessment involving the comparison domain of birds. Performance on all knowledge measures improved significantly across the 3 weeks, with more substantial knowledge gains for higher-aptitude children. Ninety percent of children asked strategic questions that eliminated multiple items while playing Twenty Questions: Domain-specific knowledge was related to strategic questions focused on the features or behaviors taught during the curriculum, while IQ scores were related to strategic questions that did not pertain to curricular content. Because children did not demonstrate metacognitive awareness of their strategic questioning, we suggest that the curricular content prompted implicit changes in strategy use.     

Further studies of pigeons’ spatial working memory in the open-field task

In Experiments 1 and 2, pigeons’ spatial working memory in an open-field setting was examined under conditions that differed in terms of working-memory load (number of sites visited prior to a retention test) at various delays between initial choices and the retention test. In Experiment 1, pigeons were tested under two conditions of memory load (three or five sites visited prior to the delay) and two delay intervals (15 and 60 min). Accuracy declined as a function of delay but was not affected significantly by memory load. In Experiment 2A, pigeons were tested under three conditions of memory load (two, four, or six sites visited prior to the delay). In separate phases, the delay was 2, 15, and 60 min. Accuracy was not affected by memory load in any of these phases. In Experiment 2B, three conditions of memory load (two, four, or six sites visited prior to the delay) were tested at two delays (2 and 60 min) within a test phase. Accuracy declined with increasing delay, but memory load again had no significant effects. These results are inconsistent with previous suggestions that pigeons’ retention of spatial information may decline as working-memory load is increased. In Experiment 3, cue-manipulation tests confirmed that pigeons’ choice behavior in the open-field task is controlled by memory for previously visitad room locations.     

Explorations of crystallized intelligence: Completion tests,cloze tests,and knowledge

An attempt is made to reconcile two historically important tools for the assessment of intelligence and the prediction of academic achievement with extant theories of verbal–crystallized–knowledge aspects of adult abilities. A study of 167 adults ranging in age from 18 to 69 reasserts the importance of individual differences in completion test and cloze test performance in accounting for both measures of crystallized intelligence (Gc) and four scales of knowledge (biology, U.S. history, U.S. literature, and technology). The completion tests were found to account for all of the variance in Gc and knowledge that the cloze tests accounted for, and resulted in incremental predictive validity for both domains. In addition, completion and cloze tests were found to have a suppressor effect on the relationship between Gc and Age. We note that C. Spearman's [The nature of “Intelligence” and the principles of cognition. New York: MacMillan (1927).] assertion, namely that the completion test had higher correlations with intelligence than any other measure. Our results suggest that abstract reasoning may be far less useful in predicting learning and performance than the completion test is.     

Modality of language shapes working memory: evidence from digit span and spatial span in ASL signers

Deaf children who are native users of American Sign Language (ASL) and hearing children who are native English speakers performed three working memory tasks. Results indicate that language modality shapes the architecture of working memory. Digit span with forward and backward report, performed by each group in their native language, suggests that the language rehearsal mechanisms for spoken language and for sign language differ in their processing constraints. Unlike hearing children, deaf children who are native signers of ASL were as good at backward recall of digits as at forward recall, suggesting that serial order information for ASL is stored in a form that does not have a preferred directionality. Data from a group of deaf children who were not native signers of ASL rule out explanations in terms of a floor effect or a nonlinguistic visual strategy. Further, deaf children who were native signers outperformed hearing children on a nonlinguistic spatial memory task, suggesting that language expertise in a particular modality exerts an influence on nonlinguistic working memory within that modality. Thus, language modality has consequences for the structure of working memory, both within and outside the linguistic domain.     

Fluid reasoning,working memory and planning ability in assessment of risk for mathematical difficulties

ABSTRACT

The demands on mathematical problem-solving have increased in almost all school systems internationally and may constitute a barrier for children with special educational needs (SEN). This study explored the role of fluid reasoning (FR), working memory (WM) and complex executive function of planning (EF) in children (N = 62) referred for assessment of SEN, and specifically of risk for mathematical difficulties (MD). Performances on FR, WM and complex EF of planning were used to predict risk for MD. Results showed that planning ability predicted children at risk for MD, beyond FR or WM ability, when comparing with children not at risk for MD. It was concluded that assessing the complex EF of planning in addition to FR and WM ability is crucial in identifying children at risk for MD. The importance of understanding how planning ability affects children’s mathematical problem-solving is discussed, in relation to assessment and teaching practices.     

Cognitive preconditions of early reading and spelling: a latent-variable approach with longitudinal data

The aim of the present study was to empirically disentangle the interdependencies of the impact of nonverbal intelligence, working memory capacities, and phonological processing skills on early reading decoding and spelling within a latent variable approach. In a sample of 127 children, these cognitive preconditions were assessed before the onset of formal education, whereas reading as well as spelling achievement was measured at the end of grade 1. The findings indicate that working memory does contribute to the prediction of early reading and spelling, and that this contribution outperforms that of general intelligence and phonological recoding from long-term memory during the early steps of reading and spelling acquisition. Moreover, the results show that phonological awareness mediates the effects of working memory capacities on early literacy outcomes. The role of working memory and phonological awareness as key cognitive preconditions of early reading and spelling are discussed.     

Comparing the contribution of two tests of working memory to reading in relation to phonological awareness and rapid naming speed

The purpose of this study was to compare the contribution of two different versions of working memory to word reading and reading comprehension in relation to phonological awareness and rapid naming speed. Fifty children were administered two measures of working memory, namely an adaptation of the Daneman and Carpenter sentence span task and Sentence Question, tests of phonological awareness, rapid naming speed, word reading and reading comprehension. The results indicated that Sentence Question accounted for unique variance over and beyond the effects of Daneman and Carpenter's sentence span task, whereas the latter did not when the effects of Sentence Question were partialled out. In addition, both phonological awareness and rapid naming were accounting for unique variance beyond the effects of working memory in predicting reading. The role of working memory on reading is discussed, and future directions for research are suggested.