Hanging on the telephone: Maintaining visuospatial bootstrapping over time in working memory.

Visuospatial bootstrapping (VSB) refers to the phenomenon in which performance on a verbal working memory task can be enhanced by presenting the verbal material within a familiar visuospatial configuration. This effect is part of a broader literature concerning how working memory is influenced by use of multimodal codes and contributions from long-term memory. The present study aimed to establish whether the VSB effect extends over a brief (5-s) delay period, and to explore the possible mechanisms operating during retention. The VSB effect, as indicated by a verbal recall advantage for digit sequences presented within a familiar visuospatial configuration (modelled on the T-9 keypad) relative to a single-location display, was observed across four experiments. The presence and size of this effect changed with the type of concurrent task activity applied during the delay. Articulatory suppression (Experiment 1) increased the visuospatial display advantage, while spatial tapping (Experiment 2) and a visuospatial judgment task (Experiment 3) both removed it. Finally, manipulation of the attentional demands placed by a verbal task also reduced (but did not abolish) this effect (Experiment 4). This pattern of findings demonstrates how provision of familiar visuospatial information at encoding can continue to support verbal working memory over time, with varying demands on modality-specific and general processing resources.

Age-related differentiation in verbal and visuospatial working memory processing in childhood.

Working memory (WM), a key feature of the cognitive system, allows for maintaining and processing information simultaneously and in a controlled manner. WM processing continuously develops across childhood, with significant increases both in verbal and visuospatial WM. Verbal and visuospatial WM may show different developmental trajectories, as verbal (but not visuospatial) WM relies on internal verbal rehearsal, which is less developed in younger children. We examined complex VWM and VSWM performance in 125 younger (age 4-6 years) and 101 older (age 8-10 years) children. Latent multi-group modeling showed that (1) older children performed better on both verbal and visuospatial WM span tasks than younger children, (2) both age groups performed better on verbal than visuospatial WM, and (3) a model with two factors representing verbal and visuospatial WM fit the data better than a one-factor model. Importantly, the correlation between the two factors was significantly higher in younger than in older children, suggesting an age-related differentiation of verbal and spatial WM processing in middle childhood. Age-related differentiation is an important characteristic of cognitive functioning and thus the findings contribute to our general understanding of WM processing.

Gaze-based rehearsal in children under 7: a developmental investigation of eye movements during a serial spatial memory task.

The emergence of strategic verbal rehearsal at around 7 years of age is widely considered a major milestone in descriptions of the development of short-term memory across childhood. Likewise, rehearsal is believed by many to be a crucial factor in explaining why memory improves with age. This apparent qualitative shift in mnemonic processes has also been characterized as a shift from passive visual to more active verbal mnemonic strategy use, but no investigation of the development of overt spatial rehearsal has informed this explanation. We measured serial spatial order reconstruction in adults and groups of children 5-7 years old and 8-11 years old, while recording their eye movements. Children, particularly the youngest children, overtly fixated late-list spatial positions longer than adults, suggesting that younger children are less likely to engage in covert rehearsal during stimulus presentation than older children and adults. However, during retention the youngest children overtly fixated more of the to-be-remembered sequences than any other group, which is inconsistent with the idea that children do nothing to try to remember. Altogether, these data are inconsistent with the notion that children under 7 do not engage in any attempts to remember. They are most consistent with proposals that children's style of remembering shifts around age 7 from reactive cue-driven methods to proactive, covert methods, which may include cumulative rehearsal.

Opportunity for verbalization does not improve visual change detection performance: A state-trace analysis.

Evidence suggests that there is a tendency to verbally recode visually-presented information, and that in some cases verbal recoding can boost memory performance. According to multi-component models of working memory, memory performance is increased because task-relevant information is simultaneously maintained in two codes. The possibility of dual encoding is problematic if the goal is to measure capacity for visual information exclusively. To counteract this possibility, articulatory suppression is frequently used with visual change detection tasks specifically to prevent verbalization of visual stimuli. But is this precaution always necessary? There is little reason to believe that concurrent articulation affects performance in typical visual change detection tasks, suggesting that verbal recoding might not be likely to occur in this paradigm, and if not, precautionary articulatory suppression would not always be necessary. We present evidence confirming that articulatory suppression has no discernible effect on performance in a typical visual change-detection task in which abstract patterns are briefly presented. A comprehensive analysis using both descriptive statistics and Bayesian state-trace analysis revealed no evidence for any complex relationship between articulatory suppression and performance that would be consistent with a verbal recoding explanation. Instead, the evidence favors the simpler explanation that verbal strategies were either not deployed in the task or, if they were, were not effective in improving performance, and thus have no influence on visual working memory as measured during visual change detection. We conclude that in visual change detection experiments in which abstract visual stimuli are briefly presented, pre-cautionary articulatory suppression is unnecessary.

Dissociable mechanisms underlying individual differences in visual working memory capacity.

Individuals scoring relatively high on measures of working memory tend to be more proficient at controlling attention to minimize the effect of distracting information. It is currently unknown whether such superior attention control abilities are mediated by stronger suppression of irrelevant information, enhancement of relevant information, or both. Here we used steady-state visual evoked potentials (SSVEPs) with the Eriksen flanker task to track simultaneously the attention to relevant and irrelevant information by tagging target and distractors with different frequencies. This design allowed us to dissociate attentional biasing of perceptual processing (via SSVEPs) and stimulus processing in the frontal cognitive control network (via time-frequency analyses of EEG data). We show that while preparing for the upcoming stimulus, high- and low-WMC individuals use different strategies: High-WMC individuals show attentional suppression of the irrelevant stimuli, whereas low-WMC individuals demonstrate attentional enhancement of the relevant stimuli. Moreover, behavioral performance was predicted by trial-to-trial fluctuations in strength of distractor-suppression for high-WMC participants. We found no evidence for WMC-related differences in cognitive control network functioning, as measured by midfrontal theta-band power. Taken together, these findings suggest that early suppression of irrelevant information is a key underlying neural mechanism by which superior attention control abilities are implemented.

Asymmetric binding in serial memory for verbal and spatial information.

As the number of studies showing that items can be retained as bound representations in memory increases, researchers are beginning to investigate how the different features are bound together. In the present study, we examined the relative importances of the verbal and spatial features in serial memory for visual stimuli. Participants were asked to memorize the order of series of letters presented visually in different locations on the computer screen. The results showed that manipulating the phonological similarity of the letters affected recall of their spatial locations, but that increasing the complexity of the spatial pattern had no effect on recall of the letters. This finding was observed in both order reconstruction (Exps. 1 and 2) and probe serial recall (Exps. 3 and 4), suggesting that verbal-spatial binding in serial memory for visual information is asymmetric.

The developing impact of verbal labels on visual memories in children.

The capacity limitations of visual working memory may be bypassed by verbal labeling. In adults, labeling increases estimates of both quantity and quality of visual working memory. However, we do not know when children begin to use labeling and whether labeling similarly benefits visual memories of children under and over age 7. We assessed whether children benefit from prompted and spontaneous labeling opportunities, examining how labeling affects the storage of categorical (prototypical) and continuous (fine-grained) color information. Participants memorized colored candies for a continuous reproduction test either while remaining silent, labeling the colors aloud, or saying irrelevant syllables (discouraging verbal labeling). Mixture modeling confirmed that both categorical and continuous representations increased with age. Our labeling manipulation showed that spontaneous labeling increased with age. For the youngest children, prompted labeling especially boosted categorical memory, whereas labeling benefited categorical and continuous memory similarly in the older age groups. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The effect of metacognitive executive function training on children's executive function, proactive control, and academic skills.

The current study investigated the effects of metacognitive and executive function (EF) training on childhood EF (inhibition, working memory [WM], cognitive flexibility, and proactive/reactive control) and academic skills (reading, reasoning, and math) among children from disadvantaged backgrounds. Children (N = 134, Mage = 8.70 years) were assigned randomly to the three training groups: (a) metacognitive training of basic EF processes (meta-EF), (b) training of basic EF processes (basic-EF), and (c) active controls (active control). They underwent 16 training sessions over the course of 2 months. No effects of EF and/or metacognitive training were found for academic outcomes. However, both meta-EF and basic-EF groups demonstrated greater gains than the active control group on proactive control engagement and WM, suggesting that EF training promotes a shift to more mature ways of engaging EF. Our findings suggest minimal near- and far-transfer effects of metacognitive training but highlight that proactive engagement of EF can be promoted through EF training in children. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Impact of memory load on processing diminishes rapidly during retention in a complex span paradigm.

Previous work with complex memory span tasks, in which simple choice decisions are imposed between presentations of to-be-remembered items, shows that these secondary tasks reduce memory span. It is less clear how reconfiguring and maintaining various amounts of information affects decision speeds. We introduced preliminary "lead-in" decisions and postencoding "lead-out" decisions to isolate potential influences of reconfiguration and maintenance on decision speeds. Compared with preliminary lead-in choice responses, the response associated with the first memory item slowed substantially. As the list accumulated, decision responses slowed even more. After presentation of the list was complete, decision responses sped rapidly: within a few seconds, decisions were at least as fast as when remembering a single item. These patterns appeared consistently regardless of differences in list length (4, 5, 6, or 7 to-be-remembered items) and response mode (spoken, selection via mouse). This pattern of findings is inconsistent with the idea that merely holding information in mind conflicts with attention-demanding decision tasks. Instead, it is likely that reconfiguring memory items for responding is the source of conflict between memory and processing in complex span tasks. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Storage and processing in working memory: A single, domain-general resource explains multitasking.

An ongoing major debate centers around whether multitasking in working memory, that is, performing several mental activities at once, is supported by multiple specialized domain-specific or by a single-purpose domain-general cognitive resources. Working memory theories differ in their explanations and predictions about when performing two mental tasks causes performance failures, versus when two processes can be carried out concurrently with negligible cognitive costs. In particular, the predictions of domain-specific and domain-general views on working memory are in conflict with one another when it comes to the cognitive cost associated with concurrent verbal and visuospatial processing and storage tasks. Previous tests of these predictions using traditional methods have led to ambiguous and inconsistent conclusions, however. To make critical progress in this theoretical debate, we used a radically different approach combining Bayesian state-trace analysis with an experimental design fully crossing processing and storage tasks differing only in the domain of representation (verbal vs. visuospatial). Across two experiments, we show unambiguously that a single, domain-general factor can account for briefly maintaining verbal and visuospatial information in a multitasking scenario. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Encode a Letter and Get Its Location for Free? Assessing Incidental Binding of Verbal and Spatial Features.

Previous studies have demonstrated that when presented with a display of spatially arranged letters, participants seem to remember the letters' locations when letters are the focus of a recognition test, but do not remember letters' identity when locations are tested. This strong binding asymmetry suggests that encoding location may be obligatory when remembering letters, which requires explanation within theories of working memory. We report two studies in which participants focused either on remembering letters or locations for a short interval. At test, positive probes were either intact letter-location combinations or recombinations of an observed letter and another previously occupied location. Incidental binding is observed when intact probes are recognized more accurately or faster than recombined probes. Here, however, we observed no evidence of incidental binding of location to letter in either experiment, neither under conditions where participants focused on one feature exclusively for a block, nor where the to-be-remembered feature was revealed prior to encoding with a changing pre-cue, nor where the to-be-remembered feature was retro-cued and therefore unknown during encoding. Our results call into question the robustness of a strong, consistent binding asymmetry. They suggest that while incidental location-to-letter binding may sometimes occur, it is not obligatory.

Lexical access speed and the development of phonological recoding during immediate serial recall.

A recent Registered Replication Report (RRR) of the development of verbal rehearsal during serial recall (Elliott et al., 2021) revealed that children verbalized at younger ages than previously thought (Flavell et al., 1966), but did not identify sources of individual differences. Here we use mediation analysis to reanalyze data from the 934 children ranging from 5 to 10 years old from the RRR for that purpose. From ages 5 to 7, the time taken for a child to label pictures (i.e. isolated naming speed) predicted the child's spontaneous use of labels during a visually-presented serial reconstruction task, despite no need for spoken responses. For 6- and 7-year-olds, isolated naming speed also predicted recall. The degree to which verbalization mediated the relation between isolated naming speed and recall changed across development. All relations dissipated by age 10. The same general pattern was observed in an exploratory analysis of delayed recall for which greater demands are placed on rehearsal for item maintenance. Overall, our findings suggest that spontaneous phonological recoding during a standard short-term memory task emerges around age 5, increases in efficiency during the early elementary school years, and is sufficiently automatic by age 10 to support immediate serial recall in most children. Moreover, the findings highlight the need to distinguish between phonological recoding and rehearsal in developmental studies of short-term memory.

Maintaining binding in working memory: comparing the effects of intentional goals and incidental affordances.

Much research on memory for binding depends on incidental measures. However, if encoding associations benefits from conscious attention, then incidental measures of binding memory might not yield a sufficient understanding of how binding is accomplished. Memory for letters and spatial locations was compared in three within-participants tasks, one in which binding was not afforded by stimulus presentation, one in which incidental binding was possible, and one in which binding was explicitly to be remembered. Some evidence for incidental binding was observed, but unique benefits of explicit binding instructions included preserved discrimination as set size increased and drastic reduction in false alarms to lures that included a new spatial location and an old letter. This suggests that substantial cognitive benefits, including enhanced memory for features themselves, might occur through intentional binding, and that incidental measures of binding might not reflect these advantages.

An assessment of fixed-capacity models of visual working memory.

Visual working memory is often modeled as having a fixed number of slots. We test this model by assessing the receiver operating characteristics (ROC) of participants in a visual-working-memory change-detection task. ROC plots yielded straight lines with a slope of 1.0, a tell-tale characteristic of all-or-none mnemonic representations. Formal model assessment yielded evidence highly consistent with a discrete fixed-capacity model of working memory for this task.

WoMMBAT: A user interface for hierarchical Bayesian estimation of working memory capacity.

The change detection paradigm has become an important tool for researchers studying working memory. Change detection is especially useful for studying visual working memory, because recall paradigms are difficult to employ in the visual modality. Pashler (Perception & Psychophysics, 44, 369-378, 1988) and Cowan (Behavioral and Brain Sciences, 24, 87-114, 2001) suggested formulas for estimating working memory capacity from change detection data. Although these formulas have become widely used, Morey (Journal of Mathematical Psychology, 55, 8-24, 2011) showed that the formulas suffer from a number of issues, including inefficient use of information, bias, volatility, uninterpretable parameter estimates, and violation of ANOVA assumptions. Morey presented a hierarchical Bayesian extension of Pashler's and Cowan's basic models that mitigates these issues. Here, we present WoMMBAT (Working Memory Modeling using Bayesian Analysis Techniques) software for fitting Morey's model to data. WoMMBAT has a graphical user interface, is freely available, and is cross-platform, running on Windows, Linux, and Mac operating systems.

Seven-year-olds allocate attention like adults unless working memory is overloaded.

Previous studies have indicated that visual working memory performance increases with age in childhood, but it is not clear why. One main hypothesis has been that younger children are less efficient in their attention; specifically, they are less able to exclude irrelevant items from working memory to make room for relevant items. We examined this hypothesis by measuring visual working memory capacity under a continuum of five attention conditions. A recognition advantage was found for items to be attended as opposed to ignored. The size of this attention-related effect was adult-like in young children with small arrays, suggesting that their attention processes are efficient even though their working memory capacity is smaller than that of older children and adults. With a larger working memory load, this efficiency in young children was compromised. The efficiency of attention cannot be the sole explanation for the capacity difference.

Consistent use of proactive control and relation with academic achievement in childhood.

As children become older, they better maintain task-relevant information in preparation of upcoming cognitive demands. This is referred to as proactive control, which is a key component of cognitive control development. However, it is still uncertain whether children engage in proactive control consistently across different contexts and how proactive control relates to academic abilities. This study used two common tasks-the AX Continuous Performance Task (AX-CPT) and the Cued Task-Switching Paradigm (CTS)-to examine whether proactive control engagement in 102 children (age range: 6.91-10.91 years) converges between the two tasks and predicts academic abilities. Proactive control indices modestly correlated between tasks in higher but not lower working-memory children, suggesting that consistency in proactive control engagement across contexts is relatively low during childhood but increases with working memory capacity. Further, working memory (but not verbal speed) predicted proactive control engagement in both tasks. While proactive control as measured by each task predicted math and reading performance, only proactive control measured by CTS additionally predicted reasoning, suggesting that proactive control can be used as a proxy for academic achievements.

Author Correction: A consensus-based transparency checklist.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Perceptual grouping boosts visual working memory capacity and reduces effort during retention.

Consistent, robust boosts to visual working memory capacity are observed when colour-location arrays contain duplicate colours. The prevailing explanation suggests that duplicated colours are encoded as one perceptual group. If so, then we should observe not only higher working memory capacity overall for displays containing duplicates, but specifically an improved ability to remember unique colours from displays including duplicates compared with displays comprising all uniquely coloured items. Furthermore, less effort should be required to retain displays as colour redundancy increases. I recorded gaze position and pupil sizes during a visual change detection task including displays of 4-6 items with either all unique colours, two items with a common colour, or three items with a common colour in samples of young and healthy elderly adults. Increased redundancy was indeed associated with higher estimated working memory capacity, both for tests of duplicates and uniquely coloured items. Redundancy was also associated with decreased pupil size during retention, especially in young adults. While elderly adults also benefited from colour redundancy, spillover to unique items was less obvious with low redundancy than in young adults. This experiment confirms previous findings and presents complementary novel evidence linking perceptual grouping via colour redundancy with decreased mental effort.

Sensory-motor integration and brain lesions: Progress toward explaining domain-specific phenomena within domain-general working memory.

Reports of rare patients who seem to lack the ability to retain certain types of information across brief delays have long sustained the popular idea that newly-perceived verbal, visual, and spatial information is initially recorded in separate, specialized short-term memory buffers. However, evidence from these same cases includes puzzling details that question explanations based on isolated deficits to a specialized storage system. We highlight consistent findings from patients with deficient auditory short-term memory that warrant further investigation and may challenge the specialized store account, including that short-term recognition memory performance appears to be much stronger than recall, and not so obviously impaired. We also describe the substantial problems for the broader memory system caused by assuming that the patients' deficits are focused in a specialized module. We suggest that a sensory-motor integration account of the patient cases may adequately explain these patterns, and therefore presents a path toward incorporating into the embedded processes framework greater clarity about how domain-specific phenomena in immediate memory tasks arise. We further contend that applying ideas about sensory-motor recruitment could improve working memory theory.