Difficulties in solving algebra story problems with secondary pupils

This literature review aims to analyze the role of individual differences in working memory capacity in following instructions based on theoretical perspectives and empirical evidence. Individual differences in working memory capacity have an impact on the encoding, and retrieval stage. In general, the output from the review stated that the performance difference between individuals relates to the experimental design and treatment, which include delivery of the instructions, presentation of objects, the length of instructions, involvement of dual tasks, and retrieval methods. In addition, the contents of instructions can be transferred into working memory space if the individuals can give a high level of attention and control the attention to suppress the distractors. Therefore, the ability to follow instructions depends on the individual's understanding of the instructions' meaning and matching them with the available space of their working memory (capacity). This review also adds value and suggestions to the need to conduct more research on the role of working memory capacity in following instructions.

The nature of parietal contributions to working memory (WM) remain poorly understood but of considerable interest. We previously reported that posterior parietal damage selectively impaired WM probed by recognition (Berryhill and Olson, 2008a). Recent studies provided support using a neuromodulatory technique, transcranial direct current stimulation (tDCS) applied to the right parietal cortex (P4). These studies confirmed parietal involvement in WM because parietal tDCS altered WM performance: anodal current tDCS improved performance in a change detection task, and cathodal current tDCS impaired performance on a sequential presentation task. Here, we tested whether these complementary results were due to different degrees of parietal involvement as a function of WM task demands, WM task difficulty, and/or participants’ WM capacity. In Experiment 1, we applied cathodal and anodal tDCS to the right parietal cortex and tested participants on both previously used WM tasks. We observed an interaction between tDCS (anodal, cathodal), WM task difficulty, and participants’ WM capacity. When the WM task was difficult, parietal stimulation (anodal or cathodal) improved WM performance selectively in participants with high WM capacity. In the low WM capacity group, parietal stimulation (anodal or cathodal) impaired WM performance. These nearly equal and opposite effects were only observed when the WM task was challenging, as in the change detection task. Experiment 2 probed the interplay of WM task difficulty and WM capacity in a parametric manner by varying set size in the WM change detection task. Here, the effect of parietal stimulation (anodal or cathodal) on the high WM capacity group followed a linear function as WM task difficulty increased with set size. The low WM capacity participants were largely unaffected by tDCS. These findings provide evidence that parietal involvement in WM performance depends on both WM capacity and WM task demands. We discuss these findings in terms of alternative WM strategies employed by low and high WM capacity individuals. We speculate that low WM capacity individuals do not recruit the posterior parietal lobe for WM tasks as efficiently as high WM capacity individuals. Consequently, tDCS provides greater benefit to individuals with high WM capacity.

The effects of working memory (WM) capacity on mathematical ability are well known. This relationship is seen mainly for the capacity of visuospatial WM, while the capacity of the phonological loop of WM, which is associated with processing sound and speech information, has been suggested to have a minor effect on mathematical ability in adults. Nonetheless, involvement of the language neural networks in mathematical thought remains controversial. We have studied the effects of the capacity of the phonological loop of WM on the rate and correctness of solution of mathematical and verbal tasks in young, healthy, right-handed volunteers who either had higher education or were students at institutions teaching mathematics and humanities. Subjects in the mathematics group (N = 10) solved all tasks with measures of solution correctness (CA) and response time (RT) which were significantly better than values for subjects of the humanities group (N = 10). The capacity of the phonological loop of WM showed no difference between the two groups but had different effects on CA and RT values for tasks in mathematicians and humanities specialists. Spearman correlation analysis for each group separately showed that the capacity of WM had positive effects on CA for all mathematical tasks only in the mathematicians group, where it had no effect on RT, while the reverse tendency was seen in the humanities group. The capacity of WM in the mathematicians group correlated inversely with RT for logical tasks on arithmetic sequences. Our results provide indirect evidence that WM in the verbal domain can influence mathematical ability, especially when tasks require the involvement of logical thought.

The study of working memory capacity is of outmost importance in cognitive psychology as working memory is at the basis of general cognitive function. Although the working memory capacity limit has been thoroughly studied, its origin still remains a matter of strong debate. Only recently has the role of visual saliency in modulating working memory storage capacity been assessed experimentally and proved to provide valuable insights into working memory function. In the computational arena, attractor networks have successfully accounted for psychophysical and neurophysiological data in numerous working memory tasks given their ability to produce a sustained elevated firing rate during a delay period. Here we investigate the mechanisms underlying working memory capacity by means of a biophysically-realistic attractor network with spiking neurons while accounting for two recent experimental observations: 1) the presence of a visually salient item reduces the number of items that can be held in working memory, and 2) visually salient items are commonly kept in memory at the cost of not keeping as many non-salient items.Our model suggests that working memory capacity is determined by two fundamental processes: encoding of visual items into working memory and maintenance of the encoded items upon their removal from the visual display. While maintenance critically depends on the constraints that lateral inhibition imposes to the mnemonic activity, encoding is limited by the ability of the stimulated neural assemblies to reach a sufficiently high level of excitation, a process governed by the dynamics of competition and cooperation among neuronal pools. Encoding is therefore contingent upon the visual working memory task and has led us to introduce the concept of effective working memory capacity (eWMC) in contrast to the maximal upper capacity limit only reached under ideal conditions.

Kidney Stone Size and Hounsfield Units Predict Successful Shockwave Lithotripsy in Children

of Employees with ADHD, 6 • Research Findings, 8 Working memory has been a highly important theoretical construct in cognitive psychology and has been defined as “a brain system that provides temporary storage and manipulation of the information necessary for... complex cognitive tasks” (Baddeley, 1992, p. 556). Recently, much interest has been created by claims that cognitive training can enhance working memory capacity (e.g., Diamond & Lee, 2011; Klingberg, 2010). On this basis, it has been suggested that working memory training programs can ameliorate a range of different learning disorders, such as ADHD, reading and language disorders, and mathematics disorder. It has also been claimed that working memory training can enhance cognitive abilities and scholastic attainment in typically developing children and adults. Theoretically, a range of different models has been suggested to explain the nature of the relationship between working memory and cognitive functioning (see Case, 1985). A model that has been highly cited in the literature on working memory training is based on the view that working memory capacity puts constraints on executive attentional capacity in general (Engle, 2002). In this sense, working memory capacity is seen as isomorphic with executive attention. Therefore, researchers have suggested that such constraints on working memory capacity will have important repercussions for cognitive development (see Case, 1985). Thus, an impairment in working memory has been put forward as a possible explanation for such learning disorders as reading disorders (Swanson, 2006), mathematics disorders (Passolunghi, 2006), autism spectrum disorder (Kenworthy, Yerys, Anthony, & Wallace, 2008), and specific language impairment (Archibald & Gathercole, 2006). For ADHD, numerous of studies have demonstrated that children with this disorder typically have poor performance on working memory tests compared with children without such problems, and impaired working memory has often been considered a core feature of ADHD (see Barkley, 2005; Martinussen et al., 2005). A dominant account in the field of ADHD has been that working memory problems not only lead to problems related to attention and keeping stimuli in mind but also in guiding goal-directed behavior, effective self-regulation, and

Working memory (WM) is a core executive function that allows individuals to hold, process and manipulate information. WM capacity has been repeatedly nominated as a key factor in human cognitive evolution; nevertheless, little is known about the WM abilities of our closest primate relatives. In this study, we examined signatures of WM ability in chimpanzees (Pan troglodytes). Standard WM tasks for humans (Homo sapiens) often require participants to continuously update their WM. In Experiment 1, we implemented this updating requirement in a foraging situation: zoo-housed chimpanzees (n = 13) searched for food in an array of containers. To avoid redundant searches, they needed to continuously update which containers they had already visited (similar to WM paradigms for human children) with 15 s retention intervals in between each choice. We examined chimpanzees' WM capacity and to what extent they used spatial cues and object features to memorize their previous choices. In Experiment 2, we investigated how susceptible their WM was to attentional interference, an important signature, setting WM in humans apart from long-term memory. We found large individual differences with some individuals remembering at least their last four choices. Chimpanzees used a combination of spatial cues and object features to remember which boxes they had chosen already. Moreover, their performance decreased specifically when competing memory information was introduced. Finally, we found that individual differences in task performance were highly reliable over time. Together, these findings show remarkable similarities between human and chimpanzee WM abilities despite evolutionary and life-history differences.

<p class="a"><span lang="EN-US">In this research, authors examine how individual differences in working memory capacity and Working Memory updating influence differences in impulsivity in risky decision making and behaviors. This study makes attempt to address extension of related works on the relationship between working memory, impulsivity and risky decision making and behaviors in adolescents. A large sample (420) of boy secondary grade students involved in this research; this study indicated that working memory capacity and updating Working Memory moderate some of impulsivity and high risk behaviors and decision making. Individuals with low working memory capacity and high impulsivity compared to individuals with high working memory capacity and high impulsivity are more likely subjected to risky decision making. Further, high risk behaviors are more salient in individuals with low updating Working Memory and high impulsivity. </span></p>

Speed and capacity of working memory and executive function in schizophrenia compared to unipolar depression

Evidence is accumulating that the classic two-stage model of visual STM (VSTM), comprising iconic memory (IM) and visual working memory (WM), is incomplete. A third memory stage, termed fragile VSTM (FM), seems to exist in between IM and WM [Vandenbroucke, A. R. E., Sligte, I. G., & Lamme, V. A. F. Manipulations of attention dissociate fragile visual STM from visual working memory. Neuropsychologia, 49, 1559-1568, 2011; Sligte, I. G., Scholte, H. S., & Lamme, V. A. F. Are there multiple visual STM stores? PLoS One, 3, e1699, 2008]. Although FM can be distinguished from IM using behavioral and fMRI methods, the question remains whether FM is a weak expression of WM or a separate form of memory with its own neural signature. Here, we tested whether FM and WM in humans are supported by dissociable time-frequency features of EEG recordings. Participants performed a partial-report change detection task, from which individual differences in FM and WM capacity were estimated. These individual FM and WM capacities were correlated with time-frequency characteristics of the EEG signal before and during encoding and maintenance of the memory display. FM capacity showed negative alpha correlations over peri-occipital electrodes, whereas WM capacity was positively related, suggesting increased visual processing (lower alpha) to be related to FM capacity. Furthermore, FM capacity correlated with an increase in theta power over central electrodes during preparation and processing of the memory display, whereas WM did not. In addition to a difference in visual processing characteristics, a positive relation between gamma power and FM capacity was observed during both preparation and maintenance periods of the task. On the other hand, we observed that theta-gamma coupling was negatively correlated with FM capacity, whereas it was slightly positively correlated with WM. These data show clear differences in the neural substrates of FM versus WM and suggest that FM depends more on visual processing mechanisms compared with WM. This study thus provides novel evidence for a dissociation between different stages in VSTM.

Previous studies found that episodic long-term memory (eLTM) enhances working memory (WM) performance when both novel and previously learnt word pairs must be retained on a short-term basis. However, there is uncertainty regarding how and when WM draws on eLTM. Three possibilities are (a) that people draw on eLTM only if WM capacity is exceeded; (b) that there is always a contribution of eLTM to WM performance, irrespective of whether prior knowledge is helpful or not; or (c) benefits of prior knowledge are specific to comparisons between conditions which are similarly ambiguous concerning whether LTM may be useful. We built on the assumption that under conditions of a contribution from LTM, these LTM traces of memoranda could benefit or hamper performance in WM tasks depending on the match between the traces stored in LTM and the ones to-be stored in WM in the current trial, yielding proactive facilitation (PF) and proactive interference (PI), respectively. Across four experiments, we familiarized participants with some items before they completed a separate WM task. In accordance with possibility (a) we show that there are indeed conditions in which only WM contributes to performance. Performance deteriorated with the addition of stimuli from eLTM when WM load was low, but not when it was high; and an exchange of information between LTM and WM occurred only when WM capacity was exceeded, with PI and PF effects affecting immediate memory performance in verbal and visual tasks only at higher set sizes.

Dissociation of working memory impairments and attention-deficit/hyperactivity disorder in the brain

Predicting distracted driving: The role of individual differences in working memory

Cochlear implants (CIs) provide significant benefits for profoundly deaf children in their language and cognitive development. However, it remains unclear whether Mandarin-speaking young children with early implantation can develop age-equivalent phonological awareness (PA) skill and working memory (WM) capacity as their normal hearing (NH) peers. The aim of this study was to investigate PA and WM in preschool-aged children with or without hearing loss and to examine the relationship between the two basic skills. The data were collected from 16 Mandarin-speaking preschoolers with CIs and 16 age-matched children with NH. All preschool participants were instructed to complete four phonological detection tasks and four digit span tasks. Linear mixed-effects modeling was performed to evaluate PA and WM performances between two groups across different tasks. CI preschoolers showed comparable performances on par with NH controls in phonological detections and visual digit spans. In addition, Pearson correlation analysis revealed a positive relationship between phonological detections and auditory digit spans in preschool-aged children with CIs. With early implantation, the congenitally deaf children were capable of developing age-appropriate PA skill and WM capacity, which have practical implications for aural rehabilitation in this special pediatric population.

Introduction: Working memory is assumed to play a major part in hearing and communication in everyday listening situations. Our working memory stores information, but in suboptimal listening conditions, interfering stimuli can lead to information only being partially stored, or even missed. Research suggests that a high working memory capacity (WMC) might not just be a result of a large store, but in addition good inhibitory control can facilitate working memory, and therefore aid in situations where focus on a target stimulus while ignoring distractors is needed.Objective: The aim of the present study was to investigate how individual WMC, cognitive inhibition, and lexical decision relate to listening to speech under adverse conditions in two separate groups: 46 young normally hearing (NH) and 40 elderly hearing-impaired (HI) individuals.Results: It showed that lexical access was of little importance for young NH individuals in a speech-in-noise test, but that high lexical decision-making was associated with lower signal-to-noise ratios for the elderly HI individuals. The results also showed that WMC was of importance for word recognition in a speech-in-noise test for elderly participants, when the 80% word recognition criterion was targeted, but not for the young NH individuals. Finally, results suggest that cognitive inhibition, as measured with the Hayling task, was important for young NH individuals when listening conditions are suboptimal.Conclusion: In conclusion, hearing loss is a strong contributing factor to declines in the ability to recognize speech in noise, and in order to assess speech-recognition-in-noise performance, individual differences in WMC and cognitive inhibition should be taken into consideration. Future research should include various age groups, with and without hearing loss, as well as measures of WMC, cognitive inhibition, and lexical access when assessing the ability to listen to speech under adverse conditions.