Is the binding of visual features in working memory resource-demanding?

The episodic buffer component of working memory is assumed to play a role in the binding of features into chunks. A series of experiments compared memory for arrays of colors or shapes with memory for bound combinations of these features. Demanding concurrent verbal tasks were used to investigate the role of general attentional processes, producing load effects that were no greater on memory for feature combinations than for the features themselves. However, the binding condition was significantly less accurate with sequential rather than simultaneous presentation, especially for items earlier in the sequence. The findings are interpreted as evidence of a relatively automatic but fragile visual feature binding mechanism in working memory. Implications for the concept of an episodic buffer are discussed.     

Is the focus of attention in working memory expanded through practice?

This article reinvestigates the claim by P. Verhaeghen, J. Cerella, and C. Basak (2004) that the focus of attention in working memory can be expanded from 1 to 4 items through practice. Using a modified version of Verhaeghen et al.'s n-back paradigm, Experiments 1 and 3 show that a signature of a one-item focus, the time cost for switching between items in working memory, persists over practice. Verhaeghen et al. reported a shift over practice from a step function to a linear slope of reaction times over set size and argued that it reflects the expansion of the focus. With an improved counterbalancing scheme, a continuously increasing slope was found even without practice in Experiment 2. The results question the hypothesis that the focus is expanded through practice. They are in line with predictions from a model that distinguishes a one-item focus from a direct-access region holding about 4 items.     

Are schemas sufficient to interpret the personalization effect? Only if long-term working memory backs up

IntroductionIn the field of education, results have shown that text personalization allows for a processing of textual information. Several researchers have explained this advantage using the concept of “schema” but have not taken into account the linguistic nature of the texts.ObjectiveIn this study, we tested the importance of texts in the personalization effect. To do so, four groups of participants were contrasted with regard to the type of material (lists vs. texts) and personalization (personalized vs. non-personalized).MethodPersonalization consisted of introducing, or not, biographical elements allowing the reader to have, or not, a very familiar material to read. Therefore, two personalized groups that read some verbal material (lists or texts) mentioning some familiar locations were compared to two non-personalized groups that read verbal material (lists or texts) featuring unfamiliar locations. For the four groups, each location was associated with two objects. After the presentation phase, participants had to recognize the objects.ResultsAs expected, the personalized group recognized the objects more rapidly than the other group. A second finding showed that when the locations were not inserted in the texts (i.e., in lists), the personalization effect disappeared.ConclusionResults suggest that an explanation just in terms of “schemas” is insufficient. We think that the long-term working memory theory (Ericsson & Kintsch, 1995) allows us to complete this explanation thanks to the concept of episodic text memory.     

Does working memory training promote the use of strategies on untrained working memory tasks?

Adaptive computerized training has been associated with significant enhancements in untrained working memory tasks, but the nature of the cognitive changes that underpin these improvements are not yet fully understood. Here, we investigate the possibility that training stimulates the use of memory-related strategies. In a randomized controlled trial, participants completed four tests of working memory before receiving adaptive working memory training, nonadaptive working memory training with low memory loads, or no training. Open-ended interviews about strategy use were conducted after the administration of untrained working memory tasks at two time points. Those in the adaptive and nonadaptive groups completed the assessments before (T1) and after (T2) 10 training sessions. The no-training group completed the same set of tasks at T1 and T2, without any training between assessment points. Adaptive training was associated with selective improvements in untrained tests of working memory, accompanied by a significant increase in the use of a grouping strategy for visuospatial short-term memory and verbal working memory tasks. These results indicate that training-related improvements in working memory may be mediated by implicit and spontaneous changes in the use of strategies to subsegment sequences of information into groups for recall when the tasks used at test overlap with those used during training.     

Is working memory necessary for implementation intentions to enhance prospective memory in older adults with cognitive problems?

Implementation intentions are an effective strategy for improving prospective memory in older adults. However, their efficacy has never been assessed in older individuals with cognitive problems (i.e., individuals with subjective memory complaints or objective memory impairments). Furthermore, although most authors consider implementation intentions to depend on automatic processes, some studies have shown the necessity of residual preserved controlled processes for implementation intentions to be efficient. We examined the efficacy of implementation intentions in prospective memory in 45 older participants consulting a memory clinic. Half of the participants were instructed to form an implementation intention, the other half receiving standard instructions. Analyses showed that working memory moderated the efficacy of implementation intentions, which were efficient only in individuals with better working memory. These results corroborate the claim that a minimal level of cognitive resources is required for the technique, although implementation intentions might depend principally on automatic processes.     

Is working memory capacity a causal factor in fluid intelligence?

Psychonomic Bulletin & Review - It is well established that measures of reasoning ability and of working memory capacity (WMC) correlate positively. However, the question of what explains this...     

Is cognition the secret to working dog success?

Animal Cognition - Dogs’ special relationship with humans not only makes them ubiquitous in our lives, but working dogs specifically perform essential functions for us such as sniffing out...     

Nonverbal working memory of humans and monkeys: Rehearsal in the sketchpad?

Investigations of working memory tend to focus on the retention of verbal information. The present experiments were designed to characterize the active maintenance rehearsal process used in the retention of visuospatial information. Rhesus monkeys (Macaca mulatta;N=6) were tested as well as humans (totalN=90) because these nonhuman primates have excellent visual working memory but, unlike humans, cannot verbally recode the stimuli to employ verbal rehearsal mechanisms. A series of experiments was conducted using a distractor-task paradigm, a directed forgetting procedure, and a dual-task paradigm. No evidence was found for an active maintenance process for either species. Rather, it appears that information is maintained in the visuospatial sketchpad without active rehearsal.     

Is light in pictures presumed to come from the left side?

For good ecological reasons humans assume that the illumination in pictures comes from overhead rather than from below. Recent work has also raised the possibility that the preferred angle of illumination is between 20 degrees and 30 degrees to the left of vertical, although the ecological basis for that is obscure. We describe two studies of this question. In study 1, twenty subjects looked in free, unrestricted vision, at a picture of a single 'bubble' which appeared either convex if the illumination was from above, or concave if the illumination was from below. There was no evidence in study 1 that illumination from the left produced a different appearance from illumination from the right, the preferred angle of illumination being 0.5 degrees to the right of vertical. In study 2, on forty subjects, there was fast presentation (200 ms) of an array of 16 bubbles, one of which, the target, was illuminated from the opposite direction to the others, and hence 'popped out' from the display, appearing concave if the others were convex, or vice-versa. The preferred angle of illumination for detection of the target was about 14 degrees to the left of vertical in study 2. The estimates from studies 1 and 2 did not differ significantly, and when combined gave a preferred angle of 9 degrees to the left of vertical. The reasons for the seeming discrepancy between studies 1 and 2, or the smaller overall effect than that found in previous studies are not clear since the methodologies seem equivalent. In both studies 1 and 2 there was a highly significant association between the direction of spontaneous head tilt and preferred direction of illumination, and this factor has not previously been taken into account in studies of the phenomenon. Contrary to the study of Sun and Perona (1998, Nature Neuroscience 1 183-184), there was no association with handedness or other measures of functional lateralisation.     

Is verbal–spatial binding in working memory impaired by a concurrent memory load?

Binding processes play a critical role in memory. We investigated whether the binding of (visually presented) verbal and spatial (locations) information involves general attentional resources, as stipulated in the revised working memory model, by comparing measures of binding in the presence and absence of a concurrent memory load. Using an adaptation of a probe recognition task contrasting performance between intact and recombined conditions, we found that the concurrent retention of a sequence of three pure tones eliminated verbal–spatial binding. The present study constitutes the first to directly measure the impact of a concurrent memory load on verbal–spatial binding and suggests that such binding may indeed recruit attentional resources, consistent with some recent findings in the visual–spatial binding literature.     

Is the life-world reduction sufficient in quantum physics?

Continental Philosophy Review - According to Husserl, the epochè (or suspension of judgment) must be left incomplete. It is to be performed step by step, thus defining various layers of...     

Does working memory training lead to generalized improvements in children with low working memory? A randomized controlled trial

Children with low working memory typically make poor educational progress, and it has been speculated that difficulties in meeting the heavy working memory demands of the classroom may be a contributory factor. Intensive working memory training has been shown to boost performance on untrained memory tasks in a variety of populations. This first randomized controlled trial with low working memory children investigated whether the benefits of training extend beyond standard working memory tasks to other more complex activities typical of the classroom in which working memory plays a role, as well as to other cognitive skills and developing academic abilities. Children aged 7–9 years received either adaptive working memory training, non‐adaptive working memory training with low memory loads, or no training. Adaptive training was associated with selective improvements in multiple untrained tests of working memory, with no evidence of changes in classroom analogues of activities that tax working memory, or any other cognitive assessments. Gains in verbal working memory were sustained one year after training. Thus the benefits of working memory training delivered in this way may not extend beyond structured working memory tasks.     

Is the contribution of the amygdala to the sex- and enhancement-related effects of emotional memory time-dependent?

A new focus in the field of emotional memory is the study of sex-related differences. Whether the sex-related lateralization of amygdala function (i.e., the female-left/male-right effect) in the emotional enhancement of memory (EEM) is time-dependent remains unclear. To evaluate this phenomenon, we conducted a two time-point study (20 min vs. 24 h) using fMRI and behavioral paradigms. We found that the right amygdala predicted 20-min EEM, while the left amygdala predicted 24-h EEM. The sex-related lateralization of amygdala function was not detected in either the 20-min or the 24-h EEM. Our results further confirm and extend the idea that the amygdala exhibits a lateralized and time-dependent dissociation, occurring even in the 24-h EEM relative to the 20-min EEM. The present and previous studies indicate that sex-related lateralization of amygdala function occurs in the 2- to 3-week EEM, but it does not occur in the 1-week, 24-h, or less than 30-min EEM, suggesting that this effect on emotional memory may also be time-dependent.     

Do gains in working memory capacity explain the written self-disclosure effect?

Klein and Boals (2001) concluded that expressive writing about negative life events improves health by reducing intrusive thoughts, as measured by the Impact of Events Scale (IES), and thus freeing working memory (WM) capacity. We replicated their WM gain and rejected the possibility that it reflected task practice alone. We extended their work by showing that such WM effects and reductions in self-reported health symptoms can be observed within a short time frame of a week in a normal population of college students and can occur without reductions in IES scores. Two alternative explanations are discussed of how WM gains can be observed in the written self-disclosure effect without reductions in the frequency of intrusive thoughts and avoidance attempts.     

Does strategic memory training improve the working memory performance of younger and older adults?

The paper examines the effect of strategic training on the performance of younger and older adults in an immediate list-recall and a working memory task. The experimental groups of younger and older adults received three sessions of memory training, teaching the use of mental images to improve the memorization of word lists. In contrast, the control groups were not instructed to use any particular strategy, but they were requested to carry out the memory exercises. The results showed that strategic training improved performance of both the younger and older experimental groups in the immediate list recall and in the working memory task. Of particular interest, the improvement in working memory performance of the older experimental group was comparable to that of the younger experimental group.     

What is the best strategy for retaining gestures in working memory?

This study aimed to determine whether the recall of gestures in working memory could be enhanced by verbal or gestural strategies. We also attempted to examine whether these strategies could help resist verbal or gestural interference. Fifty-four participants were divided into three groups according to the content of the training session. This included a control group, a verbal strategy group (where gestures were associated with labels) and a gestural strategy group (where participants repeated gestures and were told to imagine reproducing the movements). During the experiment, the participants had to reproduce a series of gestures under three conditions: “no interference”, gestural interference (gestural suppression) and verbal interference (articulatory suppression). The results showed that task performance was enhanced in the verbal strategy group, but there was no significant difference between the gestural strategy and control groups. Moreover, compared to the “no interference” condition, performance decreased in the presence of gestural interference, except within the verbal strategy group. Finally, verbal interference hindered performance in all groups. The discussion focuses on the use of labels to recall gestures and differentiates the induced strategies from self-initiated strategies.     

The importance of working memory updating in the Prisoner’s dilemma

Successful cooperation requires that humans can flexibly adjust choices to their partner’s behaviour. This, in turn, presupposes a representation of a partner’s past decisions in working memory. The aim of the current study was to investigate the role of working memory processes in cooperation. For that purpose, we tested the effects of working memory updating (Experiment 1) and working memory maintenance demands (Experiments 2 and 3) on cooperative behaviour in the Prisoner’s dilemma game. We found that demands on updating, but not maintenance, of working memory contents impaired strategy use in the Prisoner’s dilemma. Thus, our data show that updating a partner’s past behaviour in working memory represents an important precondition for strategy use in cooperation.     

On the costs of refocusing items in working memory: a matter of inhibition or decay?

The present study investigates the mental processes that are applied to previously attended items of working memory. In an object-switching task, participants counted the number of sequentially presented objects. In Experiment 1 the processing time increased when the object category switched from the prior trial compared to a repetition. More importantly, the further in the past the last instance of a current category was presented, the more processing time was necessary - an observation suggesting passive decay rather than inhibition of previously attended items. However, results differed when only two object categories were employed. Experiment 2 suggests that the lack of a clear indication of decay with small numbers of categories was due to participants' expectancy of category switches rather than repetitions. Taken together, the results suggest that working memory items become less accessible the longer they have not been attended to, when strategic processes are controlled.