When children forget to remember: Effects of reduced working memory availability on prospective memory performance

The preparatory attentional and memory processes theory (PAM) of prospective memory (PM) proposes that prospective remembering is influenced by the variation in the availability of WM resources. Consequently, PM should be impaired when WM resources are reduced either by direct WM manipulation or by individual differences associated with restricted WM performance. Our study tested this prediction in school-age children by examining the independent and interactive effects of three factors known to deplete availability of WM resources: increased processing demands of a concurrent arithmetic task, additional WM span requirements, and high trait anxiety. A sample of 10-year-old children (N = 128) performed a PM task, embedded in an ongoing arithmetic task, which progressively imposed greater WM processing demands. Half of these participants also concurrently carried out an embedded WM span task. The results supported the PAM hypothesis, showing that children’s PM was compromised by the restriction of WM resources, whether this resulted from increasing the processing demands on the ongoing task, from imposing additional WM span requirements, or from high trait anxiety. However, these WM-depleting factors exerted additive effects rather than an interactive impact, suggesting that they might each deplete different aspects of WM resource availability necessary for prospective remembering. Overall findings imply that children’s PM success is not only associated to their WM capacity but it mostly depends upon how many of those WM resources are available to be devoted to the PM requirement.     

Temporal tuning in the acquisition of cognitive skill

Thetemporal tuning hypothesis suggests that individuals adjust the timing of cognitive performances to achieve temporal coordination of mental processes and the data on which they operate, and that this adjustment becomes more precise with practice. Participants in two experiments performed self-paced multiple-step arithmetic tasks in which the information needed for each step was briefly displayed at the participants’ request. Timing constraints were manipulated by varying between subjects the delay between requests and displays of information. In Experiment 1, both operators and operands appeared step by step, and participants achieved a modest degree of temporal adjustment that did not change with practice. In Experiment 2, participants could preview operators while operands appeared step by step. In that experiment, participants achieved more precise temporal adjustment, and the amount of adjustment increased with practice. These results demonstrate the phenomenon of temporal tuning in symbolic cognitive skills and suggest some constraints on the ability to anticipate the time course of one’s mental processes.     

无关言语对汉字短时记忆系列回忆的影响*

采用视觉呈现字表和听觉呈现无关言语方式,探讨在字表项目保持期间阻止被试复述情况下,不同呈现位置的无关言语对汉字短时记忆系列回忆的影响。在字表保持期间,采用计算任务进行分心作业。实验结果发现：(1)无关言语对汉字短时记忆系列回忆成绩存在显著影响;(2)在字表保持期间阻止被试进行复述消除了字表呈现期间呈现无关言语对回忆成绩产生的干扰效应;(3)汉字短时记忆系列回忆成绩表现出系列位置效应。实验结果没有完全支持客体情节记忆模型。     

Relationship and transfer between mental and written arithmetic

In a first experiment, adults practiced single- and two-digit mental addition over a 6-day period. There was a clear training effect for both types of problems, even if two-digit additions were different from one day to another. Moreover, participants were tested on their written calculation abilities before and after the training programme. We showed that participants who entered the mental arithmetic training programme did not progress more in written arithmetic than participants who did not receive any training between the pre- and the post-tests. Conversely, in a second experiment, participants were trained in multidigit written addition and we examined the effect of such training on single- and two-digit mental addition. Again and trivially, there was a clear effect of training on written addition, but, more importantly, a transfer on mental addition. The implications of these results on the nature of the relationship between mental and written arithmetic are discussed.     

Magnitude processing and complex calculation is negatively impacted by mathematics anxiety while retrieval‐based simple calculation is not

Mathematics anxiety (MA) refers to the experience of negative affect when engaging in mathematical activity. According to Ashcraft and Kirk (2001), MA selectively affects calculation with high working memory (WM) demand. On the other hand, Maloney, Ansari, and Fugelsang (2011) claim that MA affects all mathematical activities, including even the most basic ones such as magnitude comparison. The two theories make opposing predictions on the negative effect of MA on magnitude processing and simple calculation that make minimal demands on WM. We propose that MA has a selective impact on mathematical problem solving that likely involves processing of magnitude representations. Based on our hypothesis, MA will impinge upon magnitude processing even though it makes minimal demand on WM, but will spare retrieval‐based, simple calculation, because it does not require magnitude processing. Our hypothesis can reconcile opposing predictions on the negative effect of MA on magnitude processing and simple calculation. In the present study, we observed a negative relationship between MA and performance on magnitude comparison and calculation with high but not low WM demand. These results demonstrate that MA has an impact on a wide range of mathematical performance, which depends on one's sense of magnitude, but spares over‐practiced, retrieval‐based calculation.     

Information acquisition strategies and the cognitive structure of arithmetic

In three experiments, we examined the sensitivity of information acquisition strategies to the underlying cognitive structure of arithmetic tasks. Previous work has shown that individuals solve arithmetic problems more quickly when they consider operators before operands. The operators establish the goal, and the operands are then assimilated into that goal. In the present experiments, participants performed arithmetic tasks in which they controlled the display of operators and operands, using separate keystrokes. The participants chose to see the operator before the operands in most conditions. This ordering was more likely when task constraints made it easier to achieve, when feedback emphasized execution time, and in a more complex multiple-step task. These results extend previous research on strategy selection and information acquisition, supporting the idea that coordination between the environment and ongoing cognition is an important feature of cognitive skill.     

EEG theta phase coupling during executive control of visual working memory investigated in individuals with schizophrenia and in healthy controls

In healthy humans, it has been shown that executive functions are associated with increased frontal-midline EEG theta activity and theta phase coupling between frontal and posterior brain regions. In individuals with schizophrenia, central executive functions are supposed to be heavily impaired. Given that theta phase coupling is causally involved in central executive functions, one would expect that patients with an executive function deficit should display abnormal EEG theta synchronization. We therefore investigated executive functioning in 21 healthy controls and 21 individuals with schizophrenia while they performed a visuospatial delayed match to sample task. The task required either high executive demands (manipulation of content in working memory [WM]) or low executive demands (retention of WM content). In addition, WM load (one vs. three items) was varied. Results indicated higher frontal theta activity for manipulation processes than for retention processes in patients with schizophrenia, as compared with healthy controls, independently of WM load. Furthermore, individuals with schizophrenia revealed a reduction in theta phase coupling during early stages of the delay period for retention, as well as for manipulation processes at high-WM loads. Deviations in theta phase coupling in individuals with schizophrenia were mainly characterized by aberrant fronto-posterior connections, but also by attenuated posterior connections during manipulation of high-WM load. To conclude, fronto-parietal theta coupling seems to be substantially involved in executive control, whereas frontal theta activity seems to reflect general task demands, such as deployment of attentional resources during WM.     

任务无关情绪刺激对工作记忆信息更新的影响:来自ERP的证据

任务无关的情绪刺激如何对工作记忆的信息更新过程产生影响还不清楚。本研究采用情绪N-back任务,结合事件相关电位技术调查情绪对工作记忆信息更新的影响。ERP结果显示,在0-back任务中,负性分心物诱发的P3显著小于中性分心物,表明其干扰了工作记忆信息更新过程;而在2-back任务中,负性分心物诱发的P3与中性分心物没有显著差异,表明其未对信息更新表现出干扰效应。该结果支持了情绪与认知加工的双竞争模型。     

The odd-even effect in Sudoku puzzles: effects of working memory, aging, and experience

The odd-even effect in numerical processing has been explained as the easier processing of even numbers compared with odd numbers. We investigated this effect in Sudoku puzzles, a reasoning problem that uses numbers but does not require arithmetic operations. Specifically, we asked whether the odd-even effect occurred with Sudoku puzzles and whether individual differences in working memory (WM), aging, and experience with Sudoku modulated this effect. We manipulated the presence of odd and even numbers in Sudoku puzzles, measured WM with the Wisconsin Card Sorting Test and backward digit span task, tested older and younger adults, and collected Sudoku experience frequency. Performance on Sudoku was more accurate for even puzzles than odd ones. Younger, experienced, and higher-WM participants were more accurate on Sudoku, but these individual difference variables did not interact with the odd-even effect. Odd numbers may impose more cognitive load than even numbers, but future research is needed to examine how age, experience, or WM may influence the odd-even effect.     

Susceptibility of spatial and verbal working memory to demands of the central executive

We used a dual-task paradigm to examine the degree to which domain-specific spatial and verbal subsystems depend on the domain-general central executive. Forty participants were asked to retain spatial or verbal information while performing a concurrent secondary task related to simple arithmetic. The secondary tasks consisted of three cognitive processes: single-digit addition, a digit-carrying operation, and digit reading. The single-digit addition and carry operation include central executive functioning, while digit reading relies solely on the phonological loop. The single-digit addition caused a performance decrement on the spatial working memory task, while the digit reading impaired performance on the verbal working memory task. The carry operation interfered with recall accuracy on both working memory tasks. The spatial working memory task was significantly correlated with the verbal working memory task only when the secondary task was more demanding on the central executive. Our results suggest that spatial working memory rather than verbal working memory is susceptible to failure of central executive functioning and that the central executive plays an important role in regulating the cognitive demands of different domains.     

Effect of working memory training on working memory,arithmetic and following instructions

Mathematical ability is dependent on specific mathematical training but also associated with a range of cognitive factors, including working memory (WM) capacity. Previous studies have shown that WM training leads to improvement in non-trained WM tasks, but the results regarding transfer to mathematics are inconclusive. In the present study, 176 children with WM deficits, aged 7–15 years performed 5 weeks of WM training. During the training period, they were assessed five times with a test of complex WM (the Odd One Out), a test of remembering and following instructions and a test of arithmetic. The improvements were compared to the performance of a control group of 304 typically developing children aged 7–15 years who performed the same transfer tasks at the same time intervals, but without training. The training group improved significantly more than the control group on all three transfer tests (all p < 0.0001), after correction for baseline performance, age and sex. The effect size for mathematics was small and the effect sizes for the WM tasks were moderate to large. The transfer increased linearly with the amount of training time and correlated with the amount of improvement on the trained tasks. These results confirm previous findings of training-induced improvements in non-trained WM tasks including the ability to follow instructions, but extend previous findings by showing improvements also for arithmetic. This is encouraging regarding the potential role of cognitive training for education, but it is desirable to find paradigms that would enhance the effect of the training on mathematics. One of the future challenges for studying training effects is combining large sample sizes with high quality and compliance, to detect relevant but smaller effects of cognitive training.     

Are Exact Calculation and Computational Estimation Categorically Different?

This study examined, through the problem‐size effect, whether exact calculation and computational estimation are categorically different. In Experiment 1, 26 teacher candidates, most of whom were female, Caucasian, and in their early 20s, estimated 27 randomly generated double‐digit multiplication problems. In Experiment 2, 44 similar participants estimated and calculated a common set of double‐digit multiplication problems. Analysis of reaction times and error rates indicates that the problem‐size effect holds true for exact calculation but not for estimation. In estimation, as problem size increases, reaction times do not increase, nor does the rate of unreasonable estimates. Instead, the difference between a factor's unit digit and the nearest ten to be rounded to was a primary contributor to the variance of reaction times. It is concluded that exact calculation and computational estimation are computationally, cognitively, and structurally different processes. Furthermore, it is suggested that estimation skills be given separate, dedicated attention in schools. Copyright © 2013 John Wiley & Sons, Ltd.     

About why there is a shift from cardinal to ordinal processing in the association with arithmetic between first and second grade

Digit comparison is strongly related to individual differences in children's arithmetic ability. Why this is the case, however, remains unclear to date. Therefore, we investigated the relative contribution of three possible cognitive mechanisms in first and second graders’ digit comparison performance: digit identification, digit–number word matching and digit ordering ability. Furthermore, we examined whether these components could account for the well‐established relation between digit comparison performance and arithmetic. As expected, all candidate predictors were related to digit comparison in both age groups. Moreover, in first graders, digit ordering and in second graders both digit identification and digit ordering explained unique variance in digit comparison performance. However, when entering these unique predictors of digit comparison into a mediation model with digit comparison as predictor and arithmetic as outcome, we observed that whereas in second graders digit ordering was a full mediator, in first graders this was not the case. For them, the reverse was true and digit comparison fully mediated the relation between digit ordering and arithmetic. These results suggest that between first and second grade, there is a shift in the predictive value for arithmetic from cardinal processing and procedural knowledge to ordinal processing and retrieving declarative knowledge from memory; a process which is possibly due to a change in arithmetic strategies at that age. A video abstract of this article can be viewed at: https://youtu.be/dDB0IGi2Hf8     

Effect of cognitive demand during training on acquisition, retention and transfer of a postural skill

The study examined whether attentional demands of a concurrent cognitive task during balance training affect the acquisition, retention and transfer of a postural control skill. Single-leg balance was evaluated in 64 volunteers (mean age 24.0 years, SD 3.10 years) while performing either a cognitive task requiring little attention (forward counting) or a highly demanding cognitive task (arithmetic manipulation) following three days of training. Skill retention was evaluated two days following the cessation of training, and transfer was determined by changes in the untrained extremity. Three training sessions induced decreases in mean sway velocity and amplitude variability. Skill retention was enhanced in the group trained under conditions with greater attentional demands, suggesting that diverting attention away from the postural task and allowing learning to involve more automatic processes may enhance the learning of such tasks. Practice induced similar changes in the trained and untrained extremities following both training protocols.     

Working memory demands modulate cognitive control in the Stroop paradigm

One important task of cognitive control is to regulate behavior by resolving information processing conflicts. In the Stroop task, e.g., incongruent trials lead to conflict-related enhancements of cognitive control and to improved behavioral performance in subsequent trials. Several studies suggested that these cognitive control processes are functionally and anatomically related to working memory (WM) functions. The present study investigated this suggestion and tested whether these control processes are modulated by concurrent WM demands. For this purpose, we performed three experiments in which we combined different WM tasks with the Stroop paradigm and measured their effects on cognitive control. We found that high WM demands led to a suppression of conflict-triggered cognitive control, whereas our findings suggest that this suppression effect is rather due to WM updating than to maintenance demands. We explain our findings by assuming that WM processes interfere with conflict-triggered cognitive control, harming the efficiency of these control processes.     

Mechanisms underlying corruption of working memory in Parkinson's disease

Working memory (WM) impairments are reported to occur in patients with Parkinson's disease (PD). However, the mechanisms are unclear. Here, we investigate several putative factors that might drive poor performance, by examining the precision of recall, the order in which items are recalled and whether memories are corrupted by random guessing (attentional lapses). We used two separate tasks that examined the quality of WM recall under different loads and retention periods, as well as a traditional digit span test. Firstly, on a simple measure of WM recall, where patients were asked to reproduce the orientation of a centrally presented arrow, overall recall was not significantly impaired. However, there was some evidence for increased guessing (attentional lapses). On a new analogue version of the Corsi-span task, where participants had to reproduce on a touchscreen the exact spatial pattern of presented stimuli in the order and locations in which they appeared, there was a reduction in the precision of spatial WM at higher loads. This deficit was due to misremembering item order. At the highest load, there was reduced recall precision, whereas increased guessing was only observed at intermediate set sizes. Finally, PD patients had impaired backward, but not forward, digit spans. Overall, these results reveal the task- and load-dependent nature of WM deficits in PD. On simple low-load tasks, attentional lapses predominate, whereas at higher loads, in the spatial domain, the corruption of mnemonic information—both order item and precision—emerge as the main driver of impairment.     

Place‐value understanding in number line estimation predicts future arithmetic performance

In multi‐digit numbers, the value of each digit is determined by its position within the digit string. Children's understanding of this place‐value structure constitutes a building block for later arithmetic skills. We investigated whether a number line estimation task can provide an assessment of place‐value understanding in first grade. We hypothesized that estimating the position of two‐digit numbers requires place‐value understanding. Therefore, we fitted a linear function to children's estimates of two‐digit numbers and considered the resulting slope as a measure of children's place‐value understanding. We observed a significant correlation between this slope and children's performance in a transcoding task known to require place‐value understanding. Additionally, the slope for two‐digit numbers assessed at the beginning of grade 1 predicted children's arithmetic performance at the end of grade 1. These results indicate that the number line estimation task may indeed constitute a valid measure for first‐graders' place‐value understanding. Moreover, these findings are hard to reconcile with the view that number line estimation directly assesses a spatial representation of numbers. Instead, our results suggest that numerical processes involved in performing the task (such as place‐value understanding) may drive the association between number line estimation and arithmetic performance.     

The influence of problem features and individual differences on strategic performance in simple arithmetic

The present study examined the influence of features differing across problems (problem size and operation) and across individuals (gender, amount of daily arithmetic practice, calculator use, and arithmetic skill) on simple arithmetic performance. Regression analyses were used to investigate the role of these variables in both strategy selection and strategy efficiency. Results show that more skilled and highly practiced students used memory retrieval more often and executed their strategies more efficiently than did less skilled and practiced students. Furthermore, calculator use correlated with both retrieval and procedural strategy efficiency but not with strategy selection. Only very small associations with gender were observed, with boys retrieving slightly faster than girls. Implications of the present findings for models of mental arithmetic are discussed.     

What makes working memory spans so predictive of high-level cognition?

Working memory (WM) span tasks involving a complex activity performed concurrently with item retention have proven to be good predictors of high-level cognitive performance. The present study demonstrates that replacing these complex self-paced activities with simpler but computer-paced processes, such as reading successive letters, yields more predictive WM span measures. This finding suggests that strategic factors do not contribute to be relationship between WM spans and high-level cognition.     

Conscious and effortful or effortless and automatic: a practice/performance paradox in motor learning

High cognitive effort has been frequently related to better indices of motor learning through the study of many different paradigms. However, automaticity presumably invokes minimal cognitive processing but has often been related to high-level motor performance, which suggests a paradox. The objective of this study was to approach this paradox by examining the viability of the use of different cognitive strategies during practice and performance which promote the benefits of high cognitive effort and automaticity. Members of the university community (14 men and 15 women) divided into 3 groups practiced a discrete precision task. All participants completed four sessions totaling 320 trials and were tested on retention and transfer seven days later. Findings suggest that it is indeed possible to benefit from both effortful and minimal cognitive processing strategies and that they should be used complementarily.