'Working Memory, Thought, and Action' is the magnum opus of one of the most influential cognitive psychologists of the past 50 years. This new volume on the model he created discusses the developments that have occurred within the model in the past twenty years, and places it within a broader context.

Working memory, an important posit in cognitive science, allows one to temporarily store and manipulate information in the service of ongoing tasks. Working memory has been traditionally classified as an explicit memory system – that is, as operating on and maintaining only consciously perceived information. Recently, however, several studies have questioned this assumption, purporting to provide evidence for unconscious working memory. In this paper, we focus on visual working memory and critically (...) examine these studies as well as studies of unconscious perception that seem to provide indirect evidence for unconscious working memory. Our analysis indicates that current evidence does not support an unconscious working memory store, though we offer independent reasons to think that working memory may operate on unconsciously perceived information. (shrink)

The capacity of visual working memory (VWM) refers to the amount of visual information that can be maintained in mind at once, readily accessible for ongoing tasks. In healthy young adults, the capacity limit of VWM corresponds to about three simple objects. While some researchers argued that VWM capacity becomes adult-like in early years of life, others claimed that the capacity of VWM continues to develop beyond middle childhood. Here we assessed whether VWM capacity reaches adult levels in (...) adolescence. Using an adaptation of the visual change detection task, we measured visual working memory capacity estimates in 13 year-olds, 16-year-olds, and young adults. We tested whether the capacity estimates observed in early or later years of adolescence were comparable to the estimates obtained from adults. Our results demonstrated that the capacity of VWM continues to develop throughout adolescence, not reaching adult levels even in 16 year-olds. These findings suggest that VWM capacity displays a prolonged development, similar to the protracted trajectories observed in various other aspects of cognition. (shrink)

High temporal resolution event-related brain potential and electroencephalographic coherence studies of the neural substrate of short-term storage in working memory indicate that the sustained coactivation of both prefrontal cortex and the posterior cortical systems that participate in the initial perception and comprehension of the retained information are involved in its storage. These studies further show that short-term storage mechanisms involve an increase in neural synchrony between prefrontal cortex and posterior cortex and the enhanced activation of long-term memory (...) representations of material held in short-term memory. This activation begins during the encoding/comprehension phase and evidently is prolonged into the retention phase by attentional drive from prefrontal cortex control systems. A parsimonious interpretation of these findings is that the long-term memory systems associated with the posterior cortical processors provide the necessary representational basis for working memory, with the property of short-term memory decay being primarily due to the posterior system. In this view, there is no reason to posit specialized neural systems whose functions are limited to those of short-term storage buffers. Prefrontal cortex provides the attentional pointer system for maintaining activation in the appropriate posterior processing systems. Short-term memory capacity and phenomena such as displacement of information in short-term memory are determined by limitations on the number of pointers that can be sustained by the prefrontal control systems. Key Words: coherence; event-related potentials; imaging; long-term memory; memory; short-term memory; working memory. (shrink)

A working memory (WM) deficit is a reliable observation in people experiencing anxiety. Whether the level of anxiety is related to the severity of WM difficulties is still an open question. In the present experiment, we investigated this aspect by testing the WM performance of people with different levels of anxiety symptoms. Participants were grouped according to self-report anxiety into a control group with low anxiety scores and an experimental group with clinically relevant anxiety. The experimental group was (...) then divided into a high anxiety group and a severe anxiety group. Participants performed a battery of WM tasks tagging different WM processes. The results showed that, compared to participants with low anxiety, participants with clinically relevant anxiety scores had reduced accuracy in all the WM tasks. Interestingly, participants with high and severe anxiety did not present any significant difference. Anxious participants showed difficulties also in cognitive domains other than WM. Hence, these results supply reliable evidence that people with clinically relevant anxiety scores present WM difficulties, irrespective of symptoms severity. The observation that anxiety compromises performance also in cognitive domains other than WM suggests that the deficit might affect fluid cognition. (shrink)

There is a wealth of evidence showing that increasing the distance between an argument and its head leads to more processing effort, namely, locality effects; these are usually associated with constraints in working memory (DLT: Gibson, 2000 ; activation-based model: Lewis and Vasishth, 2005 ). In SOV languages, however, the opposite effect has been found: antilocality (see discussion in Levy et al., 2013 ). Antilocality effects can be explained by the expectation-based approach as proposed by Levy ( 2008 (...) ) or by the activation-based model of sentence processing as proposed by Lewis and Vasishth ( 2005 ). We report an eye-tracking and a self-paced reading study with sentences in Spanish together with measures of individual differences to examine the distinction between expectation- and memory-based accounts, and within memory-based accounts the further distinction between DLT and the activation-based model. The experiments show that (i) antilocality effects as predicted by the expectation account appear only for high-capacity readers; (ii) increasing dependency length by interposing material that modifies the head of the dependency (the verb) produces stronger facilitation than increasing dependency length with material that does not modify the head; this is in agreement with the activation-based model but not with the expectation account; and (iii) a possible outcome of memory load on low-capacity readers is the increase in regressive saccades (locality effects as predicted by memory-based accounts) or, surprisingly, a speedup in the self-paced reading task; the latter consistent with good-enough parsing (Ferreira et al., 2002 ). In sum, the study suggests that individual differences in working memory capacity play a role in dependency resolution, and that some of the aspects of dependency resolution can be best explained with the activation-based model together with a prediction component. (shrink)

Working Memory (WM) skills of individuals with Down’s syndrome DS tend to be very poor compared to typically developing children of similar mental age. In particular, research has found that in individuals with DS visuo-spatial WM is better preserved than verbal WM. This study investigated whether is possible to train Short-Term Memory (STM) and WM abilities in individuals with DS. The cases of two teenage children are reported: E.H., 17 years and 3 months, and A.S., 15 years (...) and 11 months. A school-based treatment targeting visuo-spatial WM was given to E.H. and A.S. for six weeks. Both prior to and after the treatment, they completed a set of assessments to measure WM abilities and their performance was compared with younger typically developing nonverbal mental age controls. The results showed that the trained participants improved their performance in some of the trained and non-trained WM tasks proposed, especially with regard to the tasks assessing visuo-spatial WM abilities. These findings are discussed on the basis of their theoretical, educational and clinical implications. (shrink)

This target article discusses the verbal working memory system used in sentence comprehension. We review the concept of working memory as a short-duration system in which small amounts of information are simultaneously stored and manipulated in the service of accomplishing a task. We summarize the argument that syntactic processing in sentence comprehension requires such a storage and computational system. We then ask whether the working memory system used in syntactic processing is the same as (...) that used in verbally mediated tasks that involve conscious controlled processing. Evidence is brought to bear from various sources: the relationship between individual differences in working memory and individual differences in the efficiency of syntactic processing; the effect of concurrent verbal memory load on syntactic processing; and syntactic processing in patients with poor short-term memory, patients with poor working memory, and patients with aphasia. Experimental results from these normal subjects and patients with various brain lesions converge on the conclusion that there is a specialization in the verbal working memory system for assigning the syntactic structure of a sentence and using that structure in determining sentence meaning that is separate from the working memory system underlying the use of sentence meaning to accomplish other functions. We present a theory of the divisions of the verbal working memory system and suggestions regarding its neural basis. (shrink)

Working memory is a foundational construct of cognitive psychology, where it is thought to be a capacity that enables us to keep information in mind and to use that information to support goal directed behavior. Philosophers have recently employed working memory to explain central cognitive processes, from consciousness to reasoning. In this paper, I show that working memory cannot meet even a minimal account of natural kindhood, as the functions of maintenance and manipulation of (...) information that tie working memory models and theories together do not have a coherent or univocal realizer in the brain. As such, working memory cannot explain central cognition. Rather, I argue that working memory merely redescribes its target phenomenon, and in doing so it obfuscates relevant distinctions amongst the many ways that brains like ours retain and transform information in the service of cognition. While this project ultimately erodes the explanatory role that working memory has played in our understanding of cognition, it simultaneously prompts us to evaluate the function of natural kinds within cognitive science, and signals the need for a productive pessimism to frame our future study of cognitive categories. (shrink)

Visual working memory is a construct hypothesized to store a small amount of accurate perceptual information that can be brought to bear on a task. Much research concerns the construct's capacity and the precision of the information stored. Two prominent theories of VWM representation have emerged: slot-based and continuous-resource mechanisms. Prior modeling work suggests that a continuous resource that varies over trials with variable capacity and a potential to make localization errors best accounts for the empirical data. Questions (...) remain regarding the variability in VWM capacity and precision. Using a novel eye-tracking paradigm, we demonstrate that VWM facilitates search and exhibits effects of fixation frequency and recency, particularly for prior targets. Whereas slot-based memory models cannot account for the human data, a novel continuous-resource model does capture the behavioral and eye tracking data, and identifies the relevant resource as item activation. (shrink)

Preschool children have been proven to possess nonsymbolic approximate arithmetic skills before learning how to manipulate symbolic math and thus before any formal math instruction. It has been assumed that nonsymbolic approximate math tasks necessitate the allocation of Working Memory (WM) resources. WM has been consistently shown to be an important predictor of children's math development and achievement. The aim of our study was to uncover the specific role of WM in nonsymbolic approximate math. For this purpose, we (...) conducted a dual-task study with preschoolers with active phonological, visual, spatial, and central executive interference during the completion of a nonsymbolic approximate addition dot task. With regard to the role of WM, we found a clear performance breakdown in the central executive interference condition. Our findings provide insight into the underlying cognitive processes involved in storing and manipulating nonsymbolic approximate numerosities during early arithmetic. (shrink)

We examined whether positive and negative affect motivates verbal and spatial working memory processes, respectively, which have implications for the expenditure of mental effort. We argue that when emotion promotes cognitive tendencies that are goal incompatible with task demands, greater cognitive effort is required to perform well. We sought to investigate whether this increase in cognitive effort impairs behavioural control over a broad domain of self-control tasks. Moreover, we predicted that individuals with higher behavioural inhibition system (BIS) sensitivities (...) would report more negative affect within the goal incompatible conditions because such individuals report higher negative affect during cognitive challenge. Positive or negative affective states were induced followed by completing a verbal or spatial 2-back working memory task. All participants then completed one of three self-control tasks. Overall, we observed that conditions of emotion and working memory incompatibility (positive/spatial and negative/verbal) performed worse on the self-control tasks, and within the incompatible conditions individuals with higher BIS sensitivities reported more negative affect at the end of the study. The combination of findings suggests that emotion and working memory compatibility reduces cognitive effort and impairs behavioural control. (shrink)

Although working memory and information processing speed impairments in multiple sclerosis have been widely investigated, several questions, regarding the nature of these impairments and their relationship, remain unclear. The aim of this short communication article is to present an overview of our recent research findings regarding the characteristics of WM impairment in MS patients and, more precisely, the degree of impairment observed in each WM’s component, i.e., phonological loop, visuospatial sketchpad, central executive, and episodic buffer and the relationship (...) between IPS and each of the four WM components, in an attempt to expand the existing rather narrow understanding of the interconnection between reduced IPS and WM impairment. Two studies of our research team are presented here and their findings are briefly discussed, highlighting the importance of further research on a specific component, namely the episodic buffer component among MS patients. (shrink)

Working Memory plays a crucial role in many high-level cognitive processes . The prevalent view holds that active components of WM are predominantly intentional and conscious. This conception is oftentimes expressed explicitly, but it is best reflected in the nature of major WM tasks: All of them are blatantly explicit. We developed two new WM paradigms that allow for an examination of the role of conscious awareness in WM. Results from five studies show that WM can operate unintentionally (...) and outside of conscious awareness, thus suggesting that the current view should be expanded to include implicit WM. (shrink)

Angry faces have been shown to be detected more efficiently in a crowd of distractors compared to happy faces, known as the anger superiority effect (ASE). The present study investigated whether the ASE could be modified by top-down manipulation of working memory (WM), in central and peripheral visual fields. In central vision, participants held a colour in WM for a final memory test while simultaneously performing a visual search task that required them to determine whether a face (...) showed a different expression from other coloured faces. The colour held in WM matched either the colour of the target face (target-matching), the colour of a distractor face (distractor-matching), or neither (non-matching). Results showed that the ASE was observed when the probability of target-matching trials was low. However, when the top-down WM effect was strengthened by raising the probability of target-matching trials, the ASE in the target-matching condition was completely eliminated. Intriguingly, when the visual search task was substituted by a peripheral crowding task, similar results to central vision were found in the target-matching condition. Taken together, our findings indicate that the ASE is subject to the top-down WM effect, regardless of the visual field. (shrink)

Neural network models of memory are notorious for catastrophic interference: Old items are forgotten as new items are memorized (French, 1999; McCloskey & Cohen, 1989). While working memory (WM) in human adults shows severe capacity limitations, these capacity limitations do not reflect neural network style catastrophic interference. However, our ability to quickly apprehend the numerosity of small sets of objects (i.e., subitizing) does show catastrophic capacity limitations, and this subitizing capacity and WM might reflect a common capacity. (...) Accordingly, computational investigations (Knops, Piazza, Sengupta, Eger & Melcher, 2014; Sengupta, Surampudi & Melcher, 2014) suggest that mutual inhibition among neurons can explain both kinds of capacity limitations as well as why our ability to estimate the numerosity of larger sets is limited according to a Weber ratio signature. Based on simulations with a saliency map‐like network and mathematical proofs, we provide three results. First, mutual inhibition among neurons leads to catastrophic interference when items are presented simultaneously. The network can remember a limited number of items, but when more items are presented, the network forgets all of them. Second, if memory items are presented sequentially rather than simultaneously, the network remembers the most recent items rather than forgetting all of them. Hence, the tendency in WM tasks to sequentially attend even to simultaneously presented items might not only reflect attentional limitations, but also an adaptive strategy to avoid catastrophic interference. Third, the mean activation level in the network can be used to estimate the number of items in small sets, but it does not accurately reflect the number of items in larger sets. Rather, we suggest that the Weber ratio signature of large number discrimination emerges naturally from the interaction between the limited precision of a numeric estimation system and a multiplicative gain control mechanism. (shrink)

Recent advances in philosophical thinking about consciousness, such as cognitive phenomenology and mereological analysis, provide a framework that facilitates using computational models to explore issues surrounding the nature of consciousness. Here we suggest that, in particular, studying the computational mechanisms of working memory and its cognitive control is highly likely to identify computational correlates of consciousness and thereby lead to a deeper understanding of the nature of consciousness. We describe our recent computational models of human working (...) class='Hi'>memory and propose that three computational correlates of consciousness follow from the results of this work: itinerant attractor sequences, top-down gating, and very fast weight changes. Our current investigation is focused on evaluating whether these three correlates are sufficient to create more complex working memory models that encompass compositionality and basic causal inference. We conclude that computational models of working memory are likely to be a fruitful approach to advancing our understanding of consciousness in general and in determining the long-term potential for development of an artificial consciousness specifically. (shrink)

ObjectivesWorking memory is essential for daily life skills like reading comprehension, reasoning, and problem-solving. Healthy aging of the brain goes along with working memory decline that can affect older people’s independence in everyday life. Interventions in the form of cognitive training are a promising tool for delaying age-related working memory decline, yet the underlying structural plasticity of white matter is hardly studied.MethodsWe conducted a longitudinal diffusion tensor imaging study to investigate the effects of an intensive (...) four-week adaptive working memory training on white matter integrity quantified by global and tract-wise mean diffusivity. We compared diffusivity measures of fiber tracts that are associated with working memory of 32 young and 20 older participants that were randomly assigned to a working memory training group or an active control group.ResultsThe behavioral analysis showed an increase in working memory performance after the four-week adaptive working memory training. The neuroanatomical analysis revealed a decrease in mean diffusivity in the working memory training group after the training intervention in the right inferior longitudinal fasciculus for the older adults. There was also a decrease in mean diffusivity in the working memory training group in the right superior longitudinal fasciculus for the older and young participants after the intervention.ConclusionThis study shows that older people can benefit from working memory training by improving their working memory performance that is also reflected in terms of improved white matter integrity in the superior longitudinal fasciculus and the inferior longitudinal fasciculus, where the first is an essential component of the frontoparietal network known to be essential in working memory. (shrink)

Working memory (WM) is a cognitive system that allows us to select, organise, and integrate perceptual information with memories and current goal-directed intentions. As such, this system is central to day-to-day functioning and would be expected to be especially important in decision making and problem solving. We hypothesised that to the extent that individuals differ in WM capacity they would also be differentially vulnerable to the experience of depression and anxiety. Undergraduate students completed a computerised change detection task (...) in which storage capacity and filtering efficiency measures were obtained. It was found that low WM storage and poor filtering efficiency interacted to predict higher levels of emotional distress as measured by self-reported depressive symptoms, ruminative coping, and state anxiety. It was suggested that low capacity and a poor ability to ignore task-irrelevant information may lead to poorer problem solving, more extreme judgements of oneself and circumstances, increased rumination, and poorer emotional regulation. (shrink)

Previous work suggests that threat-related stimuli are stored to a greater degree in working memory compared to neutral stimuli. However, most of this research has focused on stimuli with physically salient threat attributes, failing to account for how a “neutral” stimulus that has acquired threat-related associations through differential aversive conditioning influences working memory. The current study examined how differentially conditioned safe and threat stimuli are stored in working memory relative to a novel, non-associated stimuli. (...) Participants completed a differential fear conditioning task followed by a change detection task consisting of three conditions across two loads. Results revealed individuals successfully learned to distinguishing CS+ from CS– conditions during the differential aversive conditioning task. Our working memory outcomes indicated successful load manipulation effects, but no statistically significant differences in accuracy, response time, or Pashler’s K measures of working memory capacity between CS+, CS–, or N conditions. However, we observed significantly reduced RT difference scores for the CS+ compared to CS– condition, indicating greater RT differences between the CS+ and N condition vs. the CS– and N condition. These findings suggest that differentially conditioned stimuli have little impact on behavioral outcomes of working memory compared to novel stimuli that had not been associated with previous safe of aversive outcomes, at least in healthy populations. (shrink)

The neural basis of phonological working memory was investigated through an examination of the effects of irrelevant speech distractors and disruptive neural stimulation from transcranial magnetic stimulation. Embedded processes models argue that the same regions involved in speech perception are used to support phonological WM whereas buffer models assume that a region separate from speech perception regions is used to support WM. Thus, according to the embedded processes approach but not the buffer approach, irrelevant speech and TMS to (...) the speech perception region should disrupt the decoding of phonological WM representations. According to the buffer account, decoding of WM items should be possible in the buffer region despite distraction and should be disrupted with TMS to this region. Experiment 1 used fMRI and representational similarity analyses with a delayed recognition memory paradigm using nonword stimuli. Results showed that decoding of memory items in the speech perception regions was possible in the absence of distractors. However, the decoding evidence in the left STG was susceptible to interference from distractors presented during the delay period whereas decoding in the proposed buffer region persisted. Experiment 2 examined the causal roles of the speech processing region and the buffer region in phonological WM performance using TMS. TMS to the SMG during the early delay period caused a disruption in recognition performance for the memory nonwords, whereas stimulations at the STG and an occipital control region did not affect WM performance. Taken together, results from the two experiments are consistent with predictions of a buffer model of phonological WM, pointing to a critical role of the left SMG in maintaining phonological representations. (shrink)

We agree with Caplan & Waters that there are problems with the single-resource theory of sentence comprehension. However, we challenge their dual-resource alternative on theoretical and empirical grounds and point to a more coherent solution that abandons the notion of working memory resources.

Working memory is a cognitive process that involves maintaining and manipulating information for a short period of time. WM is central to many cognitive processes and declines rapidly with age. Deficits in WM are seen in older adults and in patients with dementia, schizophrenia, major depression, mild cognitive impairment, Alzheimer’s disease, etc. The frontal, parietal, and occipital cortices are significantly involved in WM processing and all brain oscillations are implicated in tackling WM tasks, particularly theta and gamma bands. (...) The theta/gamma neural code hypothesis assumes that retained memory items are recorded via theta-nested gamma cycles. Neuronal oscillations can be manipulated by sensory, invasive- and non-invasive brain stimulations. Transcranial alternating-current stimulation and repetitive transcranial magnetic stimulation are frequency-tuned non-invasive brain stimulation techniques that have been used to entrain endogenous oscillations in a frequency-specific manner. Compared to rTMS, tACS demonstrates superior cost, tolerability, portability, and safety profile, making it an attractive potential tool for improving cognitive performance. Although cognitive research with tACS is still in its infancy compared to rTMS, a number of studies have shown a promising WM enhancement effect, especially in the elderly and patients with cognitive deficits. This review focuses on the various methods and outcomes of tACS on WM in healthy and unhealthy human adults and highlights the established findings, unknowns, challenges, and perspectives important for translating laboratory tACS into realistic clinical settings. This will allow researchers to identify gaps in the literature and develop frequency-tuned tACS protocols with promising safety and efficacy outcomes. Therefore, research efforts in this direction should help to consider frequency-tuned tACS as a non-pharmacological tool of cognitive rehabilitation in physiological aging and patients with cognitive deficits. (shrink)

Concurrent working memory task reduces available attentional control resources to perform the flanker task. However, controversy exists as to whether concurrent WM task increases or decreases flanker-related N2 amplitude. In a flanker task experiment, individuals were confronted with a low, middle, or high WM load task, while electroencephalography data were recorded. The ERP results showed a larger flanker-related N2 amplitude while completing a middle or high WM load task compared to a low one. However, completing an additional high (...) WM load task could not increase flanker-related N2 amplitude versus completing an additional middle WM load task. In sum, these results suggest that WM load can impair top-down cognitive control processes, thereby hampering flanker task performance. Importantly, the present study supports the account of flanker-related N2 processes linked to top-down attentional control resource allocation, but challenges the account of flanker-related N2 reflecting response conflict processes. (shrink)

Individuals with social anxiety disorder 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 and healthy control participants either maintained or reversed 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 stimuli in working memory. (shrink)

As interest in working memory is increasing at a rapid pace, an open discussion of the central issues involved is both useful and timely. This new volume compares and contrasts conceptions of working memory, with contributions from proponents of different views.

The paper investigates relationship between working memory efficiency, defined as the result of its’ processing & storage capacity and the tendency to create assosiative memory distortions ; yield under the influence of external, suggesting factors. Both issues were examined using extended version of Deese-Roediger-McDermott procedure, modified in order to meet the study demands. Suggestion was contained in an ostentatious feedback information the participants received during the DRM procedure. Working memory was measured by standardized tasks. Study (...) included 3 conditions, differing in the quality of suggestion. Participants were assigned into 3 groups, depending on results they achieved completing the WM tasks. Obtained results alongside the previously set hypothesis, revealed that WM impacts individuals’ tendency to create false memories in DRM and that the individuals showing higher rates in WM tasks are less willing to yield to suggestion compared to those with lesser ones. It also showed that the greater amount to shift, emerges under the negative suggestion condition. Notwithstanding that the interaction effect did not achieve saliency, both analyzed factors are considered as meaningful to explain memory suggestion susceptibility in presented study. Although, obtained results emphasize the crucial role of WM efficiency, that is believed to decide the magnitude of feedback that is influential in every subject. Therefore, issue demands further exploration. (shrink)

Researchers have postulated that deficits in cognitive control are associated with, and thus may underlie, the perseverative thinking that characterises generalised anxiety disorder. We examined associations between cognitive control and levels of spontaneous state rumination following a stressor in a sample of healthy control participants and participants with GAD. We assessed cognitive control by measuring working memory capacity, defined as the ability to maintain task-relevant information by ignoring task-irrelevant information. To this end, we used an affective version of (...) the reading span task with valenced distractors. Lower WMC in the presence of negative distractors was associated with greater state rumination in the GAD group, but not in the CTL group. These findings suggest that difficulty maintaining task-relevant information due to interference from negative distractors contributes to perseverative thinking in GAD. (shrink)

Working-memory retention as activated long-term memory fails to capture orchestrated processing and storage, the hallmark of the concept of working memory. The event-related potential (ERP) data are compatible with working memory as a mental workspace that holds and manipulates information on line, which is distinct from long-term memory, and deals with the products of activated traces from stored knowledge.

The Centered Mind offers a new view of the nature and causal determinants of both reflective thinking and, more generally, the stream of consciousness. Peter Carruthers argues that conscious thought is always sensory-based, relying on the resources of the working-memory system. This system enables sensory images to be sustained and manipulated through attentional signals directed at midlevel sensory areas of the brain. When abstract conceptual representations are bound into these images, we consciously experience ourselves as making judgments or (...) arriving at decisions. However, our amodal propositional attitudes are never actually among the contents of this stream of conscious reflection. Our beliefs, goals, and decisions are only ever active in the background of consciousness, working behind the scenes. They are never themselves conscious.Drawing on extensive knowledge of the scientific literature on working memory and related topics, Carruthers challenges the central assumptions of many philosophers. In addition to arguing that non-sensory propositional attitudes are never conscious, he also shows that they are never under direct intentional control. Written with his usual clarity and directness, The Centered Mind will be essential reading for all philosophers and cognitive scientists interested in the nature of human thought processes. (shrink)

Four experiments assessed the relative involvement of different working memory components in two types of reasoning tasks: propositional and spatial reasoning. Using the secondary-task methodology, visual, central-executive, and phonological loads were realised. Although the involvement of visuospatial resources in propositional reasoning has traditionally been considered to be small, an overall analysis of the present data suggests an alternative account. A theoretical analysis of the pattern of results in terms of Evans' (1984, 1989) twostage theory of reasoning is proposed (...) and tested in Experiments 3 and 4, in which direct evidence for the alternative account was obtained: significant disruption of propositional reasoning by a concurrent spatial load. (shrink)

Number facts are commonly assumed to be verbally stored in an associative multiplication fact retrieval network. Prominent evidence for this assumption comes from so-called operand-related errors (e.g. 4 × 6 = 28). However, little is known about the development of this network in children and its relation to verbal and non-verbal memories. In a longitudinal design, we explored elementary school children from grades 3 and 4 in a multiplication verification task with the operand-related and -unrelated distractors. We examined the contribution (...) of multiplicative fact retrieval by verbal and visuo-spatial short-term and working memory. Children in grade 4 showed smaller reaction times in all conditions. However, there was no significant difference in errors between grades. Contribution of verbal and visuo-spatial working memory also changed with grade. Multiplication correlated with verbal working memory and performance in grade 3 but with visuo-spatial working memory and performance in grade 4. We suggest that the relation to verbal working memory in grade 3 indicates primary linguistic learning of and access to multiplication in grade 3 which is probably based on verbal repetition of the multiplication table heavily practiced in grades 2 and 3. However, the relation to visuo-spatial semantic working memory in grade 4 suggests that there is a shift from verbal to visual and semantic learning in grade 4. This shifting may be induced because later in elementary school, multiplication problems are rather carried out via more written, i.e., visual tasks, which also involve executive functions. More generally, the current data indicates that mathematical development is not generally characterized by a steady progress in performance; rather verbal and non-verbal memory contributions of performance shift over time, probably due to different learning contents. (shrink)

Algorithms for approximate Bayesian inference, such as those based on sampling (i.e., Monte Carlo methods), provide a natural source of models of how people may deal with uncertainty with limited cognitive resources. Here, we consider the idea that individual differences in working memory capacity (WMC) may be usefully modeled in terms of the number of samples, or “particles,” available to perform inference. To test this idea, we focus on two recent experiments that report positive associations between WMC and (...) two distinct aspects of categorization performance: the ability to learn novel categories, and the ability to switch between different categorization strategies (“knowledge restructuring”). In favor of the idea of modeling WMC as a number of particles, we show that a single model can reproduce both experimental results by varying the number of particles—increasing the number of particles leads to both faster category learning and improved strategy‐switching. Furthermore, when we fit the model to individual participants, we found a positive association between WMC and best‐fit number of particles for strategy switching. However, no association between WMC and best‐fit number of particles was found for category learning. These results are discussed in the context of the general challenge of disentangling the contributions of different potential sources of behavioral variability. (shrink)

BackgroundNeuropsychological profile of Indian Duchenne muscular dystrophy subjects remains unidentified and needs to be evaluated.MethodsA total of 69 DMD and 66 controls were subjected to detailed intelligence and neuropsychological assessment. The factor indexes were derived from various components of Malin’s Intelligence Scale for Indian Children and Rey Auditory Verbal Learning Test.ResultsPoor verbal and visual memory profiles were demonstrated by DMDs, which include RAVLT-immediate recall, RAVLT-delayed recall, Rey–Osterrieth complex figure test -IR, and RCFT-DR. RAVLT-memory efficiency index demonstrated poor verbal (...) memory efficiency. Significant differences in the functioning of working memory axis [RAVLT T1, recency T1, Digit Span Backward ] were observed along with reduced performance in visuomotor coordination, visuospatial, and visual recognition abilities. Block designing efficiency index and attention fraction showed a normal performance in DMD kids.ConclusionWorking memory deficits were found to be the crucial element of cognitive functioning in DMD cases. Working memory interventions may be beneficial to improve the neuropsychological profile in DMD. (shrink)

This study aimed to explore the influence of the visuospatial active working memory sub-components on early math skills in young children, followed longitudinally along the first two years of primary school. We administered tests investigating visual active working memory (jigsaw puzzle), spatial active working memory (backward Corsi), and math tasks to 43 children at the beginning of first grade (T1), at the end of first grade (T2), and at the end of second grade (T3). (...) Math tasks were select according to the children’s age and their levels of formal education: the “Battery for the evaluation of numerical intelligence from 4 to 6 years of age” (BIN 4–6) at T1 to test early numerical competence and the “Test for the evaluation of calculating and problem-solving abilities” (AC-MT 6–11) to test math skills at T2 and T3. Three regression models, in which the predictors were identified through a forward selection based on the use of the Bayesian information criterion (BIC) index, were performed to study the relationship between visual and spatial working memory and math ability at the three points in time. The results show that spatial working memory influences early numerical performance at T1, while early numerical performance is the unique predic-tor of math performance at T2. At the end of the second grade, the regression model reveals a relationship between math performance and both visual and spatial working memory and the attenuation of the importance of domain-specific predictors. The study depicts the dif-ferent implications of visual and spatial working memory predictors over the children’s de-velopment periods and brings additional evidence to the debate on the relationship between visuospatial working memory and math ability in young children. (shrink)

Caplan & Waters argue that the processing resources used for sentence comprehension are not drawn from an undifferentiated verbal working memory resource. This commentary cites data from normal aging to support this position. Still lacking in theory development is a specification of the transient memory representations necessary for interpretive and post-interpretive operations.

The purpose of this study was to compare working memory (WM), executive function, academic ability and problem classroom behaviors in children aged 8 to 11 years who were either identified via routine screening as having low WM, or had been diagnosed with ADHD. Standardised assessments of WM, executive function and reading and mathematics were administered to 83 children with ADHD, 50 children with low WM and 50 typically developing children. Teachers rated problem behaviors on checklists measuring attention, hyperactivity/impulsivity, (...) oppositional behavior, and difficulties associated with executive function in the classroom. The ADHD and low WM groups had highly similar WM and executive function profiles, but were distinguished in two key respects: children with ADHD had higher levels of rated and observed impulsive behavior, and children low WM had slower response times. Possible mechanisms for these common and distinct deficits are discussed. (shrink)

The current conceptualization of working memory highlights its pivotal role in the cognitive control of goal-directed behaviour, for example, by keeping task-priorities and relevant information ‘online’. Evidence has accumulated, however, that working memory contents can automatically misdirect attention and observers can only exert little intentional control to overcome irrelevant contents held in memory that are known to be misleading for behaviour. The authors discuss extant evidence on this topic and argue that obligatory functional coupling between (...) working memory and attentional selection reflects a default property of the brain which is hardwired in overlapping substrates for memory and perception. They further argue that the neuroanatomical substrates for working memory biases in vision are distinct from the classical fronto-parietal networks involved in attentional control and distinct from the mechanisms that mediate attention biases from long-term memory. Finally the authors present emerging evidence that working memory ‘guiding’ processes may operate outside conscious awareness. (shrink)

Various kinds of observations show that the ability of human beings to both consciously relive past events – episodic memory – and conceive future events, entails an active process of construction. This construction process also underpins many other important aspects of conscious human life, such as perceptions, language and conscious thinking. This article provides an explanation of what makes the constructive process possible and how it works. The process mainly relies on attentional activity, which has a discrete and periodic (...) nature, and working memory, which allows for the combination of discrete attentional operations. An explanation is also provided of how past and future events are constructed. (shrink)