Happiness increases verbal and spatial working memory capacity where sadness does not: Emotion,working memory and executive control

The effects of emotion on working memory and executive control are often studied in isolation. Positive mood enhances verbal and impairs spatial working memory, whereas negative mood enhances spatial and impairs verbal working memory. Moreover, positive mood enhances executive control, whereas negative mood has little influence. We examined how emotion influences verbal and spatial working memory capacity, which requires executive control to coordinate between holding information in working memory and completing a secondary task. We predicted that positive mood would improve both verbal and spatial working memory capacity because of its influence on executive control. Positive, negative and neutral moods were induced followed by completing a verbal (Experiment 1) or spatial (Experiment 2) working memory operation span task to assess working memory capacity. Positive mood enhanced working memory capacity irrespective of the working memory domain, whereas negative mood had no influence on performance. Thus, positive mood was more successful holding information in working memory while processing task-irrelevant information, suggesting that the influence mood has on executive control supersedes the independent effects mood has on domain-specific working memory.     

Working memory capacity and retrieval limitations from long-term memory: An examination of differences in accessibility

In two experiments, the locus of individual differences in working memory capacity and long-term memory recall was examined. Participants performed categorical cued and free recall tasks, and individual differences in the dynamics of recall were interpreted in terms of a hierarchical-search framework. The results from this study are in accordance with recent theorizing suggesting a strong relation between working memory capacity and retrieval from long-term memory. Furthermore, the results also indicate that individual differences in categorical recall are partially due to differences in accessibility. In terms of accessibility of target information, two important factors drive the difference between high- and low-working-memory-capacity participants. Low-working-memory-capacity participants fail to utilize appropriate retrieval strategies to access cues, and they also have difficulty resolving cue overload. Thus, when low-working-memory-capacity participants were given specific cues that activated a smaller set of potential targets, their recall performance was the same as that of high-working-memory-capacity participants.     

Working through the pain: Working memory capacity and differences in processing and storage under pain

It has been suggested that pain perception and attention are closely linked at both a neural and a behavioural level. If pain and attention are so linked, it is reasonable to speculate that those who vary in working memory capacity (WMC) should be affected by pain differently. This study compares the performance of individuals who differ in WMC as they perform processing and memory span tasks while under mild pain and not. While processing performance under mild pain does not interact with WMC, the ability to store information for later recall does. This suggests that pain operates much like an additional processing burden, and that the ability to overcome this physical sensation is related to differences in WMC.     

The relationship between working memory capacity and cortical activity during performance of a novel motor task

ObjectivesThis study assessed whether individual differences in working memory capacity influenced verbal-analytical processes when performing a novel motor skill.DesignParticipants performed a tennis-hitting task in two conditions: no pressure and high-pressure.MethodsEighteen young adults participated in the study. EEG coherence between the T3-F3 and T4-F4 regions in the Beta1 and Alpha2 frequencies was recorded during performance in each condition. Verbal and visuo-spatial working memory capacity were assessed using the Automated Working Memory Assessment.ResultsNo differences were found between the two conditions for hitting performance and EEG activity. However, across both conditions, verbal and visuo-spatial working memory were significant predictors of EEG coherence between the T3-F3 and T4-F4 regions in the Beta1 and Alpha2 frequencies. Larger verbal working memory capacity was associated with greater coherence while the opposite trend was observed for visuo-spatial working memory capacity.ConclusionsThese results indicate that larger verbal working memory capacity is associated with a greater tendency to use explicit processes during motor performance, whereas larger visuo-spatial working memory capacity is associated more with implicit processes. The findings are discussed with relevance to the theory of implicit motor learning.     

Working memory and fine motor skills predict early numeracy performance of children with cerebral palsy

Early numeracy is an important precursor for arithmetic performance, academic proficiency, and work success. Besides their apparent motor difficulties, children with cerebral palsy (CP) often show additional cognitive disturbances. In this study, we examine whether working memory, non-verbal intelligence, linguistic skills, counting and fine motor skills are positively related to the early numeracy performance of 6-year-old children with CP. A total of 56 children (M = 6.0, SD = 0.61, 37 boys) from Dutch special education schools participated in this cross-sectional study. Of the total group, 81% of the children have the spastic type of CP (33% unilateral and 66% bilateral), 9% have been diagnosed as having diskinetic CP, 8% have been diagnosed as having spastic and diskinetic CP and 2% have been diagnosed as having a combination of diskinetic and atactic CP. The children completed standardized tests assessing early numeracy performance, working memory, non-verbal intelligence, sentence understanding and fine motor skills. In addition, an experimental task was administered to examine their basic counting performance. Structural equation modeling showed that working memory and fine motor skills were significantly related to the early numeracy performance of the children (β = .79 and p < .001, β = .41 and p < .001, respectively). Furthermore, counting was a mediating variable between working memory and early numeracy (β = .57, p < .001). Together, these findings highlight the importance of working memory for early numeracy performance in children with CP and they warrant further research into the efficacy of intervention programs aimed at working memory training.     

Stereotype internalization and women’s math performance: The role of interference in working memory

It has long been argued that stigmatized individuals can ultimately internalize the stereotype alleging their inferiority. The present article investigated whether the internalization of the reputation of math inferiority that targets women can affect their math performance and whether this influence is caused by a disruption of working memory. A first study showed that stereotype endorsement had a significant impact on women’s statistic performance by lowering their self-evaluation of math ability even when controlling for prior achievement. A second study was designed to assess the possibility that the lower math performance displayed by women with low self-evaluation of math ability was due to interference in working memory. Using a dual task paradigm, this study showed that indeed women with low math self-evaluation displayed more errors and spent more time solving additions than women with high math self-evaluation, but mainly on difficult items of the dual task. The findings, which are congruent with an explanation in terms of a temporary disruption of working memory, are discussed.     

The role of working memory capacity in autobiographical retrieval: Individual differences in strategic search

Remembering previous experiences from one's personal past is a principal component of psychological well-being, personality, sense of self, decision making, and planning for the future. In the current study the ability to search for autobiographical information in memory was examined by having college students recall their Facebook friends. Individual differences in working memory capacity manifested itself in the search of autobiographical memory by way of the total number of friends remembered, the number of clusters of friends, size of clusters, and the speed with which participants could output their friends' names. Although working memory capacity was related to the ability to search autobiographical memory, participants did not differ in the manner in which they approached the search and used contextual cues to help query their memories. These results corroborate recent theorising, which suggests that working memory is a necessary component of self-generating contextual cues to strategically search memory for autobiographical information.     

Working memory deficits in developmental dyscalculia: The importance of serial order

Although a number of studies suggests a link between working memory (WM) storage capacity of short-term memory and calculation abilities, the nature of verbal WM deficits in children with developmental dyscalculia (DD) remains poorly understood. We explored verbal WM capacity in DD by focusing on the distinction between memory for item information (the items to be retained) and memory for order information (the order of the items within a list). We hypothesized that WM for order could be specifically related to impaired numerical abilities given that recent studies suggest close interactions between the representation of order information in WM and ordinal numerical processing. We investigated item and order WM abilities as well as basic numerical processing abilities in 16 children with DD (age: 8–11 years) and 16 typically developing children matched on age, IQ, and reading abilities. The DD group performed significantly poorer than controls in the order WM condition but not in the item WM condition. In addition, the DD group performed significantly slower than the control group on a numerical order judgment task. The present results show significantly reduced serial order WM abilities in DD coupled with less efficient numerical ordinal processing abilities, reflecting more general difficulties in explicit processing of ordinal information.     

Education does not protect against age-related decline of switching focal attention in working memory

In this experimental study, effects of age and education on switching focal attention in working memory were investigated among 44 young (20-30 years) and 40 middle-aged individuals (50-60 years). To this end, a numeric n-back task comprising two lag conditions (1- and 2-back) was administered within groups. The results revealed a comparable increase of reaction time as a function of lag across age groups, but a disproportionate decrease of accuracy in the middle-aged relative to the young group. The latter effect did not interact with education, which challenges the cognitive reserve hypothesis. Moreover, the high-educated middle-aged participants showed a greater increase of reaction time as a function of lag than their low-educated counterparts. Apparently, they were not able to sustain their relatively high response speed across conditions. These results suggest that education does not protect against age-related decline of switching focal attention in working memory.     

Working memory in social anxiety disorder: better manipulation of emotional versus neutral material in working memory

Individuals with social anxiety disorder (SAD) engage in post-event processing, a form of perseverative thinking. Given that deficits in working memory might underlie perseverative thinking, we examined working memory in SAD with a particular focus on the effects of stimulus valence. SAD (n?=?31) and healthy control (n?=?20) participants either maintained (forward trials) or reversed (backward trials) in working memory the order of four emotional or four neutral pictures, and we examined sorting costs, which reflect the extent to which performance deteriorated on the backward trials compared to the forward trials. Emotionality of stimuli affected performance of the two groups differently. Whereas control participants exhibited higher sorting costs for emotional stimuli compared to neutral stimuli, SAD participants exhibited the opposite pattern. Greater attention to emotional stimuli in SAD might facilitate the processing of emotional (vs. neutral) stimuli in working memory.     

The role of attention during retrieval in working-memory span: A dual-task study

We tested the hypothesis that retrieving target words in operation span (OSpan) involves attention-demanding processes. Participants completed the standard OSpan task and a modified version in which all equations preceded all target words. Recall took place under either full attention or easy versus hard divided-attention conditions. Recall suffered under divided attention with the recall decrement being greater for the hard secondary task. Moreover, secondary-task performance was disrupted more by the standard OSpan task than by the modified version with the hard secondary task showing the larger decrement. Finally, the time taken to start recalling the first word was considerably longer for the standard version than for the modified version. These results are consistent with the proposal that successful OSpan task performance in part involves the attention-demanding retrieval of targets from long-term memory.     

High working memory capacity does not always attenuate distraction: Bayesian evidence in support of the null hypothesis

Individual differences in working memory capacity (WMC) predict individual differences in basically all tasks that demand some form of cognitive labor, especially if the persons conducting the task are exposed to distraction. As such, tasks that measure WMC are very useful tools in individual-differences research. However, the predictive power of those tasks, combined with conventional statistical tools that cannot support the null hypothesis, also makes it difficult to study the limits of that power. In this article, we review studies that have failed to find a relationship between WMC and effects of auditory distraction on visual–verbal cognitive performance, and use meta-analytic Bayesian statistics to test the null hypothesis. The results favor the assumption that individual differences in WMC are, in fact, not (always) related to the magnitude of distraction. Implications for the nature of WMC are discussed.     

Differences between probability and frequency judgments: The role of individual differences in working memory capacity

Most theories of probability judgment assume that judgments are made by comparing the strength of a focal hypothesis relative to the strength of alternative hypotheses. In contrast, research suggests that frequency judgments are assessed using a non-comparative process; the strength of the focal hypothesis is assessed without comparing it to the strength of alternative hypotheses. We tested this distinction between probability and frequency judgments using the alternative outcomes paradigm (Windschitl, Young, & Jenson, 2002). Assuming that judgments of probability (but not judgments of frequency) entail comparing the focal hypothesis with alternative hypotheses, we hypothesized that probability judgments would be sensitive to the distribution of the alternative hypotheses and would be negatively correlated with individual differences in working memory (WM) capacity. In contrast, frequency judgments should be unrelated to the distribution of the alternatives and uncorrelated with WM-capacity. Results supported the hypotheses.     

The role of working memory capacity and interference resolution mechanisms in task switching

Theories of task switching have emphasized a number of control mechanisms that may support the ability to flexibly switch between tasks. The present study examined the extent to which individual differences in working memory (WM) capacity and two measures of interference resolution, response–distractor inhibition and resistance to proactive interference (PI), account for variability in task switching, including global costs, local costs, and N-2 repetition costs. A total of 102 young and 60 older adults were tested on a battery of tasks. Composite scores were created for WM capacity, response–distractor inhibition, and resistance to PI; shifting was indexed by rate residual scores, which combine response time and accuracy and account for individual differences in processing speed. Composite scores served as predictors of task switching. WM was significantly related to global switch costs. While resistance to PI and WM explained some variance in local costs, these effects did not reach significance. In contrast, none of the control measures explained variance in N-2 repetition costs. Furthermore, age effects were only evident for N-2 repetition costs, with older adults demonstrating larger costs than young adults. Results are discussed within the context of theoretical models of task switching.     

The precursors of mathematics learning: Working memory,phonological ability and numerical competence

This research aims at identifying the precursors of mathematics learning at the beginning of primary school. There are few experimental studies on this topic and existing ones use between-subjects designs and correlation analysis. This paper analyses longitudinal data to investigate whether the relationship between basic abilities and mathematics learning is causally interpretable, rather than one where cognitive abilities are correlated to early mathematics learning in a cross-section design.     

The effects of study order and backward associative strength on illusory recollection: A source-strength effect does not always occur

We investigated illusory recollection by dividing lists of associated words into three subsets (high, medium and low) based on their backward associative strength (BAS) to an unstudied theme. Participants studied these subsets at different visual locations on a computer screen and afterwards were given a source memory test. In Experiment 1, we varied the order in which high- and medium-BAS subsets were studied. In Experiment 2, we again manipulated study order as well as the associative strength of the medium-BAS subsets (strong or weak). Across both experiments, illusory recollection was constrained by both study order and BAS. Source attributions to the high-BAS location were more likely (a source-strength effect) when high-BAS items were studied first or studied following items of relatively low associative strength. However, attributions to the strong medium-BAS studied location were more likely when these items were studied before high-BAS items. These findings are interpreted as resulting from misbinding of source details at encoding which can be explained by the activation-monitoring theory of illusory recollection.     

The role of working memory capacity in multiple-cue probability learning

Multiple-cue probability learning (MCPL) involves learning to predict a criterion when outcome feedback is provided for multiple cues. A great deal of research suggests that working memory capacity (WMC) is involved in a wide range of tasks that draw on higher level cognitive processes. In three experiments, we examined the role of WMC in MCPL by introducing measures of working memory capacity, as well as other task manipulations. While individual differences in WMC positively predicted performance in some kinds of multiple-cue tasks, performance on other tasks was entirely unrelated to these differences. Performance on tasks that contained negative cues was correlated with working memory capacity, as well as measures of explicit knowledge obtained in the learning process. When the relevant cues predicted positively, however, WMC became irrelevant. The results are discussed in terms of controlled and automatic processes in learning and judgement.     

Misleading cues improve developmental assessment of working memory capacity: The color matching tasks

The theory of constructive operators was used as a framework to design two versions of a paradigm (color matching task, CMT) in which items are parametrically ordered in difficulty, and differ only contextually. Items in CMT-Balloon are facilitating, whereas items in CMT-Clown contain misleading cues. Participants of ages 7–14 years and adults (N = 149) were studied. We found significant model-predicted graded differences in performance between the facilitating and misleading tasks, across and within age groups, expressing age versus items’ demand interactions. Younger children were differentially affected by contextual cues. Even though both task versions were highly correlated with a well-established developmental measure of attentional capacity, CMT-Clown, which contained misleading cues, was a better measure of working memory capacity. These results show a need to estimate degree of misleadingness whenever performance levels in working memory or mental attention tasks are compared and interpreted. Developmental profiles of both tasks are discussed in terms of contextual differences and neoPiagetian stages of development.     

The effect of working memory load on semantic illusions: What the phonological loop and central executive have to contribute

When asked how many animals of each kind Moses took on the Ark, most people respond with “two” despite the substituted name (Moses for Noah) in the question. Possible explanations for semantic illusions appear to be related to processing limitations such as those of working memory. Indeed, individual working memory capacity has an impact upon how sentences containing substitutions are processed. This experiment examined further the role of working memory in the occurrence of semantic illusions using a dual-task working memory load approach. Participants verified statements while engaging in either articulatory suppression or random number generation. Secondary task type had a significant effect on semantic illusion rate, but only when comparing the control condition to the two dual-task conditions. Furthermore, secondary task performance in the random number generation condition declined, suggesting a tradeoff between tasks. Response time analyses also showed a different pattern of processing across the conditions. The findings suggest that the phonological loop plays a role in representing semantic illusion sentences coherently and in monitoring for details, while the role of the central executive is to assist gist-processing of sentences. This usually efficient strategy leads to error in the case of semantic illusions.     

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.