Developmental dissociation in the neural responses to simple multiplication and subtraction problems

Mastering single‐digit arithmetic during school years is commonly thought to depend upon an increasing reliance on verbally memorized facts. An alternative model, however, posits that fluency in single‐digit arithmetic might also be achieved via the increasing use of efficient calculation procedures. To test between these hypotheses, we used a cross‐sectional design to measure the neural activity associated with single‐digit subtraction and multiplication in 34 children from 2nd to 7th grade. The neural correlates of language and numerical processing were also identified in each child via localizer scans. Although multiplication and subtraction were undistinguishable in terms of behavior, we found a striking developmental dissociation in their neural correlates. First, we observed grade‐related increases of activity for multiplication, but not for subtraction, in a language‐related region of the left temporal cortex. Second, we found grade‐related increases of activity for subtraction, but not for multiplication, in a region of the right parietal cortex involved in the procedural manipulation of numerical quantities. The present results suggest that fluency in simple arithmetic in children may be achieved by both increasing reliance on verbal retrieval and by greater use of efficient quantity‐based procedures, depending on the operation.     

Brain lateralization of phonological awareness varies by maternal education

Socioeconomic status (SES) has been shown to influence language skills, with children of lower SES backgrounds performing worse on language assessments compared to their higher SES peers. While there is abundant behavioral research on the effects of SES, whether there are differences in the neural mechanisms used to support language skill is less established. In this study, we examined the relation between maternal education (ME), a component of SES, and neural mechanisms of language. We focused on Kindergarten children, at the beginning of formal reading education, and on a pre‐reading skill, phonological awareness—the ability to distinguish or manipulate the sounds of language. We determined ME‐related differences in neural activity by examining a skill‐matched sample of typically achieving 5‐year‐old children as they performed a rhyme judgment task. We examined brain lateralization in two language processing regions, the inferior frontal gyrus (IFG) and superior temporal gyrus (STG). In the IFG, lateralization was related to ME but not skill: children with low ME showed bilateral activation compared to children with higher ME who showed leftward lateralization. In the STG, there was a skill by ME interaction on lateralization, such that children with high ME showed a positive relation between rightward lateralization and skill and children with low ME showed a positive relation between leftward lateralization and skill. Thus, we demonstrated ME is related to differences in neural recruitment during language processing, yet this difference in recruitment is not indicative of a deficit in linguistic processing in Kindergarten children.     

The Neural Bases of Strategy and Skill in Sentence–Picture Verification

This experiment used functional Magnetic Resonance Imaging to examine the relation between individual differences in cognitive skill and the amount of cortical activation engendered by two strategies (linguistic vs. visual–spatial) in a sentence–picture verification task. The verbal strategy produced more activation in language-related cortical regions (e.g., Broca's area), whereas the visual–spatial strategy produced more activation in regions that have been implicated in visual–spatial reasoning (e.g., parietal cortex). These relations were also modulated by individual differences in cognitive skill: Individuals with better verbal skills (as measured by the reading span test) had less activation in Broca's area when they used the verbal strategy. Similarly, individuals with better visual–spatial skills (as measured by the Vandenberg, 1971, mental rotation test) had less activation in the left parietal cortex when they used the visual-spatial strategy. These results indicate that language and visual–spatial processing are supported by partially separable networks of cortical regions and suggests one basis for strategy selection: the minimization of cognitive workload.     

Visuo‐spatial play experience: forerunner of visuo‐spatial achievement in preadolescent and adolescent boys and girls?

This cross‐sectional study explored whether participation, from early childhood, in play involving different cognitive abilities predicts visuo‐spatial achievement at ages 9, 12, and 15. Based on parental assessment, prior and present practice of spatial manipulation play was found to be consistently more frequent in boys than in girls; the reverse held true for verbal expression play. Whereas boys did not significantly outperform girls in three visuo‐spatial tasks, girls were superior on a contrastive vocabulary task. In general, with IQ statistically controlled, regression analyses showed that estimated past and present spatial manipulation play predicted both genders' proficiency in the water‐level task and Embedded Figures Test, as did mothers' socioeconomic status for Block Design performance. Contrastingly, a negative relation was established between spatial manipulation play and vocabulary scores. Similar to the activity‐ability association often identified among adults, the relation established here between spatial play experience and visuo‐spatial ability was only modest. Further research should aim at more definitive conclusions through augmenting both diversity in the visuo‐spatial skills measured and sophistication in play behaviour appraisal. Copyright © 2003 John Wiley & Sons, Ltd.     

Brain hyper‐connectivity and operation‐specific deficits during arithmetic problem solving in children with developmental dyscalculia

Developmental dyscalculia (DD) is marked by specific deficits in processing numerical and mathematical information despite normal intelligence (IQ) and reading ability. We examined how brain circuits used by young children with DD to solve simple addition and subtraction problems differ from those used by typically developing (TD) children who were matched on age, IQ, reading ability, and working memory. Children with DD were slower and less accurate during problem solving than TD children, and were especially impaired on their ability to solve subtraction problems. Children with DD showed significantly greater activity in multiple parietal, occipito‐temporal and prefrontal cortex regions while solving addition and subtraction problems. Despite poorer performance during subtraction, children with DD showed greater activity in multiple intra‐parietal sulcus (IPS) and superior parietal lobule subdivisions in the dorsal posterior parietal cortex as well as fusiform gyrus in the ventral occipito‐temporal cortex. Critically, effective connectivity analyses revealed hyper‐connectivity, rather than reduced connectivity, between the IPS and multiple brain systems including the lateral fronto‐parietal and default mode networks in children with DD during both addition and subtraction. These findings suggest the IPS and its functional circuits are a major locus of dysfunction during both addition and subtraction problem solving in DD, and that inappropriate task modulation and hyper‐connectivity, rather than under‐engagement and under‐connectivity, are the neural mechanisms underlying problem solving difficulties in children with DD. We discuss our findings in the broader context of multiple levels of analysis and performance issues inherent in neuroimaging studies of typical and atypical development.     

Procedural Multimedia Presentations: The Effects of Working Memory and Task Complexity on Instruction Time and Assembly Accuracy

Procedural text conveys information of a series of steps to be performed. This study examined the role of verbal and visuo‐spatial WM in comprehension and execution of assembly instructions, as a function of format (text, images, multimedia) and task complexity (three or five steps). One hundred and eight participants read and executed 27 instructions to assemble a LEGO^TM object, in single and dual task conditions. Study times and errors during assembly were measured. Participants processed faster pictorial and multimedia instructions than text instructions, and made fewer errors in the execution of multimedia instructions. Dual task affected more text or picture‐only, than multimedia presentation. A verbal secondary task caused more errors in text or picture‐only presentations, and spatial secondary task also caused interference in text‐only instructions. Overall, these results support the multimedia advantage, and the role of both verbal and visuo‐spatial WM, when understanding instructions. Copyright © 2016 John Wiley & Sons, Ltd.     

The neural bases of strategy and skill in sentence-picture verification

This experiment used functional Magnetic Resonance Imaging to examine the relation between individual differences in cognitive skill and the amount of cortical activation engendered by two strategies (linguistic vs. visual-spatial) in a sentence-picture verification task. The verbal strategy produced more activation in language-related cortical regions (e.g., Broca's area), whereas the visual-spatial strategy produced more activation in regions that have been implicated in visual-spatial reasoning (e.g., parietal cortex). These relations were also modulated by individual differences in cognitive skill: Individuals with better verbal skills (as measured by the reading span test) had less activation in Broca's area when they used the verbal strategy. Similarly, individuals with better visual-spatial skills (as measured by the Vandenberg, 1971, mental rotation test) had less activation in the left parietal cortex when they used the visual-spatial strategy. These results indicate that language and visual-spatial processing are supported by partially separable networks of cortical regions and suggests one basis for strategy selection: the minimization of cognitive workload.     

Cognition and affective style: Individual differences in brain electrical activity during spatial and verbal tasks

Relations between brain electrical activity and performance on two cognitive tasks were examined in a normal population selected to be high on self-reported measures of Positive or Negative Affectivity. Twenty-five right-handed women, from an original pool of 308 college undergraduates, were the participants. EEG was recorded during baseline and during psychometrically matched spatial and verbal tasks. As predicted, participants who were high in Positive Affectivity performed equally well on the verbal and spatial tasks, while participants who were high in Negative Affectivity had spatial scores that were lower than their verbal scores. There were no group differences in baseline EEG. Both groups exhibited left central activation (i.e., alpha suppression) during the verbal and spatial tasks. When EEG data were analyzed separately for the group high in Positive Affectivity, there was evidence of parietal activation for the spatial task relative to the verbal task. The EEG data for the group high in Negative Affectivity had comparable EEG power values during verbal and spatial tasks at parietal scalp locations. These data suggest that, within a selected normal population, differences in affective style may interact with cognitive performance and with the brain electrical activity associated with that performance.     

What clocks tell us about the neural correlates of spatial imagery

We review a series of experimental studies aimed at answering some critical questions about the neural basis of spatial imagery. Our group used functional magnetic resonance imaging (fMRI) to explore the neural correlates of an online behaviourally controlled spatial imagery task without need for visual presentation—the mental clock task. Subjects are asked to imagine pairs of times that are presented acoustically and to judge at which of the two times the clock hands form the greater angle. The cortical activation elicited by this task was contrasted with that obtained during other visual, perceptual, verbal, and spatial imagery tasks in several block design studies. Moreover, our group performed an event‐related fMRI study on the clock task to investigate the representation of component cognitive processes in spatial imagery. The bulk of our findings demonstrates that cortical areas in the posterior parietal cortex (PPC), along the intraparietal sulcus, are robustly involved in spatial mental imagery and in other tasks requiring spatial transformations. PPC is bilaterally involved in different kinds of spatial judgement. Yet the degree to which right and left PPC are activated in different tasks is a function of task requirements. From event‐related fMRI data we obtained evidence that left and right PPC are activated asynchronously during the clock task and this could reflect their different functional role in subserving cognitive components of visuospatial imagery.     

The development of creative cognition across adolescence: distinct trajectories for insight and divergent thinking

We examined developmental trajectories of creative cognition across adolescence. Participants (N = 98), divided into four age groups (12/13 yrs, 15/16 yrs, 18/19 yrs, and 25–30 yrs), were subjected to a battery of tasks gauging creative insight (visual; verbal) and divergent thinking (verbal; visuo‐spatial). The two older age groups outperformed the two younger age groups on insight tasks. The 25–30‐year‐olds outperformed the two youngest age groups on the originality measure of verbal divergent thinking. No age‐group differences were observed for verbal divergent thinking fluency and flexibility. On divergent thinking in the visuo‐spatial domain, however, only 15/16‐year‐olds outperformed 12/13‐year‐olds; a model with peak performance for 15/16‐years‐old showed the best fit. The results for the different creativity processes are discussed in relation to cognitive and related neurobiological models. We conclude that mid‐adolescence is a period of not only immaturities but also of creative potentials in the visuo‐spatial domain, possibly related to developing control functions and explorative behavior.     

An fMRI study of sex differences in regional activation to a verbal and a spatial task

Sex differences in cognitive performance have been documented, women performing better on some phonological tasks and men on spatial tasks. An earlier fMRI study suggested sex differences in distributed brain activation during phonological processing, with bilateral activation seen in women while men showed primarily left-lateralized activation. This blood oxygen level-dependent fMRI study examined sex differences (14 men, 13 women) in activation for a spatial task (judgment of line orientation) compared to a verbal-reasoning task (analogies) that does not typically show sex differences. Task difficulty was manipulated. Hypothesized ROI-based analysis documented the expected left-lateralized changes for the verbal task in the inferior parietal and planum temporal regions in both men and women, but only men showed right-lateralized increase for the spatial task in these regions. Image-based analysis revealed a distributed network of cortical regions activated by the tasks, which consisted of the lateral frontal, medial frontal, mid-temporal, occipitoparietal, and occipital regions. The activation was more left lateralized for the verbal and more right for the spatial tasks, but men also showed some left activation for the spatial task, which was not seen in women. Increased task difficulty produced more distributed activation for the verbal and more circumscribed activation for the spatial task. The results suggest that failure to activate the appropriate hemisphere in regions directly involved in task performance may explain certain sex differences in performance. They also extend, for a spatial task, the principle that bilateral activation in a distributed cognitive system underlies sex differences in performance.     

The effects of age and professional expertise on working memory performance

Differences in professional choice and experience may explain age differences in working memory performance of elderly people. The aim of this study was to examine whether expertise and prolonged practice in verbal and visuo‐spatial abilities reduce age differences in laboratory working memory tasks. The effects of age and expertise on working memory performance were examined in three age groups in two different experiments. Firstly, the role of visuo‐spatial expertise was analysed by examining age differences in architects. Secondly, people with extensive experience in verbal abilities (literary people) were tested in order to evaluate the effect of professional verbal experience. Architects and literary people outperformed a group of unselected age peers on tasks related to professional expertise only, but not on general working memory tests. There was no interaction between age and experience, suggesting that professional experience does not increase differences between experts and non experts and cannot modulate age‐related effects. Copyright © 2008 John Wiley & Sons, Ltd.     

Neurocognitive Contributions to Motor Skill Learning: The Role of Working Memory

ABSTRACT

Researchers have begun to delineate the precise nature and neural correlates of the cognitive processes that contribute to motor skill learning. The authors review recent work from their laboratory designed to further understand the neurocognitive mechanisms of skill acquisition. The authors have demonstrated an important role for spatial working memory in 2 different types of motor skill learning, sensorimotor adaptation and motor sequence learning. They have shown that individual differences in spatial working memory capacity predict the rate of motor learning for sensorimotor adaptation and motor sequence learning, and have also reported neural overlap between a spatial working memory task and the early, but not late, stages of adaptation, particularly in the right dorsolateral prefrontal cortex and bilateral inferior parietal lobules. The authors propose that spatial working memory is relied on for processing motor error information to update motor control for subsequent actions. Further, they suggest that working memory is relied on during learning new action sequences for chunking individual action elements together.     

Developmental differences in prefrontal activation during working memory maintenance and manipulation for different memory loads

The ability to keep information active in working memory is one of the cornerstones of cognitive development. Prior studies have demonstrated that regions which are important for working memory performance in adults, such as dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC), and superior parietal cortex, become increasingly engaged across school-aged development. The primary goal of the present functional MRI study was to investigate the involvement of these regions in the development of working memory manipulation relative to maintenance functions under different loads. We measured activation in DLPFC, VLPFC, and superior parietal cortex during the delay period of a verbal working memory task in 11-13-year-old children and young adults. We found evidence for age-related behavioral improvements in working memory and functional changes within DLPFC and VLPFC activation patterns. Although activation profiles of DLPFC and VLPFC were similar, group differences were most pronounced for right DLPFC. Consistent with prior studies, right DLPFC showed an interaction between age and condition (i.e. manipulation versus maintenance), specifically at the lower loads. This interaction was characterized by increased activation for manipulation relative to maintenance trials in adults compared to children. In contrast, we did not observe a significant age-dependent load sensitivity. These results suggest that age-related differences in the right DLPFC are specific to working memory manipulation and are not related to task difficulty and/or differences in short-term memory capacity.     

Neural correlates of rumination in adolescents with remitted major depressive disorder and healthy controls

The aim of the present study was to use fMRI to examine the neural correlates of engaging in rumination among a sample of remitted depressed adolescents, a population at high risk for future depressive relapse. A rumination induction task was used to assess differences in the patterns of neural activation during rumination versus a distraction condition among 26 adolescents in remission from major depressive disorder (rMDD) and in 15 healthy control adolescents. Self-report depression and rumination, as well as clinician-rated depression, were also assessed among all participants. All of the participants recruited regions in the default mode network (DMN), including the posterior cingulate cortex, medial prefrontal cortex, inferior parietal lobe, and medial temporal gyrus, during rumination. Increased activation in these regions during rumination was correlated with increased self-report rumination and symptoms of depression across all participants. Adolescents with rMDD also exhibited greater activation in regions involved in visual, somatosensory, and emotion processing than did healthy peers. The present findings suggest that during ruminative thought, adolescents with rMDD are characterized by increased recruitment of regions within the DMN and in areas involved in visual, somatosensory, and emotion processing.     

Brain activation during spatial updating and attentive tracking of moving targets

Keeping aware of the locations of objects while one is moving requires the updating of spatial representations. As long as the objects are visible, attentional tracking is sufficient, but knowing where objects out of view went in relation to one's own body involves an updating of spatial working memory. Here, multiple object tracking was employed to study spatial updating and its neural correlates. In a dynamic 3D-scene, targets moved among visually indistinguishable distractors. The targets and distractors either stayed visible during continuous viewpoint changes or they turned invisible. The parametric variation of tracking load revealed load-dependent activations of the intraparietal sulcus, the superior parietal lobule, and the lateral occipital cortex in response to the attentive tracking task. Viewpoint changes with invisible objects that demanded retention and updating produced load-dependent activation only in the precuneus in line with its presumed involvement in updating spatial working memory.     

Socioeconomic status modifies the sex difference in spatial skill

We examined whether the male spatial advantage varies across children from different socioeconomic (SES) groups. In a longitudinal study, children were administered two spatial tasks requiring mental transformations and a syntax comprehension task in the fall and spring of second and third grades. Boys from middle- and high-SES backgrounds outperformed their female counterparts on both spatial tasks, whereas boys and girls from a low-SES group did not differ in their performance level on these tasks. As expected, no sex differences were found on the verbal comprehension task. Prior studies have generally been based on the assumption that the male spatial advantage reflects ability differences in the population as a whole. Our finding that the advantage is sensitive to variations in SES provides a challenge to this assumption, and has implications for a successful explanation of the sex-related difference in spatial skill.     

Age-Related Changes in Neural Activation During Working Memory Performance

Changes in frontal lobe functions are a typical part of aging of the brain. There are age-related declines in working memory performance, a skill requiring frontal lobe activation. This study examined neural activation, using [15 O] water positron emission tomography (PET) methodology, during performance on two verbal working memory tasks in younger and older participants. The results demonstrated the typical areas of activation associated with working memory performance (e.g., dorsolateral prefrontal cortex and inferior parietal cortex) in both groups. However, the younger participants utilized the right dorsolateral prefrontal cortex and anterior cingulate gyrus significantly more than the older participants. In turn, the older participants used the left dorsolateral prefrontal cortex significantly more than the younger participants and maintained material-specific lateralization in their pattern of activation. These findings are consistent with a previous report of different age-related patterns of frontal activation during working memory.