Training the removal of negative information from working memory: A preliminary investigation of a working memory bias modification task

Rumination in depressed adults is associated with a bias toward retaining negative information in working memory. We developed a task designed to modify this cognitive bias by having subjects repeatedly practice removing negative words from working memory, thereby enabling them to retain positive and neutral words. To assess the efficacy of this task, we recruited 60 adults who reported elevated repetitive negative thought (RNT) and randomly assigned them to receive a single administration of either the working memory bias modification (WMBM) task or a control task. Subjects in the WMBM condition exhibited greater reduction in proactive interference for negative information than did those in the control condition. These results suggest that the WMBM task reduces biased retention of negative information in working memory and, thus, may be useful in investigating the possible causal role of this cognitive bias in RNT or depression.     

Combined cognitive and parent training interventions for adolescents with ADHD and their mothers: A randomized controlled trial

This study examined the individual and combined effects of two nonpharmacological treatments for attention deficit/hyperactivity disorder (ADHD): Cogmed working memory training (CWMT) for adolescents and behavioral parent training (BPT) for mothers. Ninety-one adolescents (ages 11–15) and their mothers were randomized to one of four CWMT and BPT treatment and active control (placebo) group combinations of 5-week interventions. At pre- and posttest, mothers and teachers completed rating forms, and adolescents completed neuropsychological measures of working memory (WM). Individual intervention effects showed that treatment CWMT significantly improved WM spans, whereas there were no significant differences for treatment or control BPT on reports of parent-related outcomes. Combined treatment effects indicated an overall pattern of greatest improvements for the control CWMT/treatment BPT group, as compared to the other three groups, on adolescent WM deficit, behavioral regulation problems, and global executive deficit. Most significant effects for outcomes were main effects of improvements over time. A combination of CWMT and BPT did not result in increased treatment gains. However, potential effects of combined treatment may have been masked by greater perceived benefits arising from lack of struggle in the nonadaptive, CWMT active control condition. Future combined intervention research should focus on specific, theoretically driven WM deficits among individuals with ADHD, should include possible adaptations to the standard CWMT program, should examine effectiveness of cognitive treatments combined with contextual interventions and should utilize appropriate control groups to fully understand the unique and combined effects of interventions.     

Differences in memory functioning between children with attention-deficit/hyperactivity disorder and/or focal epilepsy

Prior research has shown that attention-deficit/hyperactivity disorder (ADHD) and epilepsy are frequently comorbid and that both disorders are associated with various attention and memory problems. Nonetheless, limited research has been conducted comparing the two disorders in one sample to determine unique versus shared deficits. Hence, we investigated differences in working memory (WM) and short-term and delayed recall between children with ADHD, focal epilepsy of mixed foci, comorbid ADHD/epilepsy and controls. Participants were compared on the Core subtests and the Picture Locations subtest of the Children’s Memory Scale (CMS). Results indicated that children with ADHD displayed intact verbal WM and long-term memory (LTM), as well as intact performance on most aspects of short-term memory (STM). They performed worse than controls on Numbers Forward and Picture Locations, suggesting problems with focused attention and simple span for visual-spatial material. Conversely, children with epilepsy displayed poor focused attention and STM regardless of the modality assessed, which affected encoding into LTM. The only loss over time was found for passages (Stories). WM was intact. Children with comorbid ADHD/epilepsy displayed focused attention and STM/LTM problems consistent with both disorders, having the lowest scores across the four groups. Hence, focused attention and visual-spatial span appear to be affected in both disorders, whereas additional STM/encoding problems are specific to epilepsy. Children with comorbid ADHD/epilepsy have deficits consistent with both disorders, with slight additive effects. This study suggests that attention and memory testing should be a regular part of the evaluation of children with epilepsy and ADHD.     

Explaining Away and the Cognitive Science of Religion

In order to evaluate the claim that theistic belief can be explained away by science, four models of the relationship between science and theism are developed and their relevance to explaining away explored. These models are then used to evaluate an argument against theistic belief based on developments in the cognitive science of religion. It is argued that even if the processes that produce theistic belief are unreliable, this is insufficient to show that explaining away takes place. Indeed, given the difficulty of showing that the conditions for explaining away are met, it is very unlikely that such an argument can succeed.     

From Gibson and Crooks to Damasio: The role of psychology in the development of driver behaviour models

This article presents a brief history and perspective of behavioural model development in traffic psychology. As one specific example of a key behavioural model, Gibson and Crooks (1938), in their classic field theoretical study, offered the first scientific attempt to deal with the issue of compensation. Two central theoretical concepts were developed: “Field of safe travel” and “Minimum stopping zone”. The interplay between the two was used to describe and explain risk compensation and illustrated by observing the impact of brakes on driver behaviour: Better brakes could make the field of safe travel – i.e. the distance to the car in front – shorter. Nearly 50 years later, the launch of Wilde’s Risk Homeostasis Theory (RHT) gave rise to a profound debate about risk homeostasis and risk compensation. The core issue in the debate was Wilde’s strict assertion that all individuals, not only car-drivers, carry an inherent target level of risk that they are seeking to maintain or restore. Gibson and Crooks fell well within psychological theories of the time, while Wilde’s RHT emerged more from control theory and economic utility theory than from psychology. In the 1990s neuroscience emerges, especially by Damasio who introduces a paradigm that has proven fruitful as a framework of more recent driver behaviour models. But neuroscience also had its forerunner in Taylor’s proposal that driver behaviour is governed by a constancy in Galvanic Skin Response (GSR) which makes driving a self-paced task aiming at keeping the GSR at a constant level. Näätänen and Summala’s integrated Taylor in their “Zero-risk model” which has persisted and still prevails as a solid and well accepted model. Psychological learning theory has, however, rarely been adequately dealt with which is quite odd given the prevalence of speeding and risk compensation which cannot escape explanations based on operant conditioning. The paper discusses the emerging role of psychology and psychological concepts that has been proposed and evolved through the development of driver behaviour models since Gibson and Crooks’ study of 1938. The views presented are subjective, they do not represent any attempt to describe the objective reality of the time.     

Scaling sporting equipment for children promotes implicit processes during performance

This study investigated whether children who used scaled equipment compared to full size equipment during a motor task demonstrated reduced conscious involvement in performance. Children (9–11 years) performed a tennis hitting task in two attention conditions (single-task and dual-task) using two types of equipment (scaled and full size). A more skilled group and a less skilled group were formed using hitting performance scores. The more skilled group displayed greater working memory capacity than the less skilled group. For both groups, hitting performance and technique were better when scaled equipment was used. Hitting performance when using scaled equipment was not disrupted in either group by a cognitively demanding secondary task; however, performance was disrupted in the less skilled group when using full size equipment. We conclude that equipment scaling may reduce working memory engagement in motor performance and discuss the findings in the context of implicit motor learning theory.     

Verbal working memory predicts co-speech gesture: Evidence from individual differences

Gesture facilitates language production, but there is debate surrounding its exact role. It has been argued that gestures lighten the load on verbal working memory (VWM; Goldin-Meadow, Nusbaum, Kelly, & Wagner, 2001), but gestures have also been argued to aid in lexical retrieval (Krauss, 1998). In the current study, 50 speakers completed an individual differences battery that included measures of VWM and lexical retrieval. To elicit gesture, each speaker described short cartoon clips immediately after viewing. Measures of lexical retrieval did not predict spontaneous gesture rates, but lower VWM was associated with higher gesture rates, suggesting that gestures can facilitate language production by supporting VWM when resources are taxed. These data also suggest that individual variability in the propensity to gesture is partly linked to cognitive capacities.     

Working memory predicts semantic comprehension in dichotic listening in older adults

Older adults have difficulty understanding spoken language in the presence of competing voices. Everyday social situations involving multiple simultaneous talkers may become increasingly challenging in later life due to changes in the ability to focus attention. This study examined whether individual differences in cognitive function predict older adults’ ability to access sentence-level meanings in competing speech using a dichotic priming paradigm. Older listeners showed faster responses to words that matched the meaning of spoken sentences presented to the left or right ear, relative to a neutral baseline. However, older adults were more vulnerable than younger adults to interference from competing speech when the competing signal was presented to the right ear. This pattern of performance was strongly correlated with a non-auditory working memory measure, suggesting that cognitive factors play a key role in semantic comprehension in competing speech in healthy aging.     

Goal neglect and knowledge chunking in the construction of novel behaviour

Task complexity is critical in cognitive efficiency and fluid intelligence. To examine functional limits in task complexity, we examine the phenomenon of goal neglect, where participants with low fluid intelligence fail to follow task rules that they otherwise understand. Though neglect is known to increase with task complexity, here we show that – in contrast to previous accounts – the critical factor is not the total complexity of all task rules. Instead, when the space of task requirements can be divided into separate sub-parts, neglect is controlled by the complexity of each component part. The data also show that neglect develops and stabilizes over the first few performance trials, i.e. as instructions are first used to generate behaviour. In all complex behaviour, a critical process is combination of task events with retrieved task requirements to create focused attentional episodes dealing with each decision in turn. In large part, we suggest, fluid intelligence may reflect this process of converting complex requirements into effective attentional episodes.     

Working memory improvement with non-invasive brain stimulation of the dorsolateral prefrontal cortex: A systematic review and meta-analysis

Recent studies have used non-invasive brain stimulation (NIBS) techniques, such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), to increase dorsolateral prefrontal cortex (DLPFC) activity and, consequently, working memory (WM) performance. However, such experiments have yielded mixed results, possibly due to small sample sizes and heterogeneity of outcomes. Therefore, our aim was to perform a systematic review and meta-analyses on NIBS studies assessing the n-back task, which is a reliable index for WM. From the first data available to February 2013, we looked for sham-controlled, randomized studies that used NIBS over the DLPFC using the n-back task in PubMed/MEDLINE and other databases. Twelve studies (describing 33 experiments) matched our eligibility criteria. Active vs. sham NIBS was significantly associated with faster response times (RTs), higher percentage of correct responses and lower percentage of error responses. However, meta-regressions showed that tDCS (vs. rTMS) presented only an improvement in RT, and not in accuracy. This could have occurred in part because almost all tDCS studies employed a crossover design, possibly due to the reliable tDCS blinding. Study design was also associated with no improvement in correct responses in the active vs. sham groups. To conclude, rTMS of the DLPFC significantly improved all measures of WM performance whereas tDCS significantly improved RT, but not the percentage of correct and error responses. Mechanistic insights on the role of DLPFC in WM are further discussed, as well as how NIBS techniques could be used in neuropsychiatric samples presenting WM deficits, such as major depression, dementia and schizophrenia.