Verbal Memory Load Research Articles

The neural coding of tonal working memory load: An functional magnetic resonance imaging study.

Tonal working memory load refers to the number of pitches held in working memory. It has been found that different verbal working memory loads have different neural coding (local neural activity pattern). However, whether there exists a comparable phenomenon for tonal working memory load remains unclear. In this study, we used a delayed match-to-sample paradigm to evoke tonal working memory. Neural coding of different tonal working memory loads was studied with a surface space and convolution neural network (CNN)-based multivariate pattern analysis (SC-MVPA) method. We found that first, neural coding of tonal working memory was significantly different from that of the control condition in the bilateral superior temporal gyrus (STG), supplement motor area (SMA), and precentral gyrus (PCG). Second, neural coding of nonadjacent tonal working memory loads was distinguishable in the bilateral STG and PCG. Third, neural coding is gradually enhanced as the memory load increases. Finally, neural coding of tonal working memory was encoded in the bilateral STG in the encoding phase and shored in the bilateral PCG and SMA in the maintenance phase.

Brain correlates of action word memory revealed by fMRI.

Understanding language semantically related to actions activates the motor cortex. This activation is sensitive to semantic information such as the body part used to perform the action (e.g. arm-/leg-related action words). Additionally, motor movements of the hands/feet can have a causal effect on memory maintenance of action words, suggesting that the involvement of motor systems extends to working memory. This study examined brain correlates of verbal memory load for action-related words using event-related fMRI. Seventeen participants saw either four identical or four different words from the same category (arm-/leg-related action words) then performed a nonmatching-to-sample task. Results show that verbal memory maintenance in the high-load condition produced greater activation in left premotor and supplementary motor cortex, along with posterior-parietal areas, indicating that verbal memory circuits for action-related words include the cortical action system. Somatotopic memory load effects of arm- and leg-related words were observed, but only at more anterior cortical regions than was found in earlier studies employing passive reading tasks. These findings support a neurocomputational model of distributed action-perception circuits (APCs), according to which language understanding is manifest as full ignition of APCs, whereas working memory is realized as reverberant activity receding to multimodal prefrontal and lateral temporal areas.

The role of domain-general attention and domain-specific processing in working memory in algebraic performance: An experimental approach.

We investigated the role of working memory in symbolic and spatial algebra and related tasks across five experiments. Each experiment combined a processing task (expression evaluation, arithmetic, coordinate plane, geometry, or mental rotation) with verbal and spatial memory loads in a dual-task design. Spatial memory was compromised in the presence of more difficult processing tasks, and verbal memory was only compromised in the presence of algebraic tasks. The latter was related to the demands of retaining quantities associated with variables in verbal memory. We suggest that both verbal and spatial working memory retention engage domain-general attention, but that their maintenance mechanisms differ. Verbal memory has attention-based and rehearsal-based mechanisms, and thus sustaining verbal information over a short period is less attention-demanding than holding spatial information. We suggest that effects of a memory load on processing (e.g., x = 6) depend on whether use of maintenance strategies are possible for the specific memory load while carrying out processing. In all, our results indicate that algebraic tasks use domain-general attention and include verbal processing of algebraic variables (i.e., information conveyed in x, y). We discuss the implications for algebra learning and working memory theories. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Visual and verbal working memory loads interfere with scene-viewing.

Working memory is thought to be divided into distinct visual and verbal subsystems. Studies of visual working memory frequently use verbal working memory tasks as control conditions and/or use articulatory suppression to ensure that visual load is not transferred to verbal working memory. Using these verbal tasks relies on the assumption that the verbal working memory load will not interfere with the same processes as visual working memory. In the present study, participants maintained a visual or verbal working memory load as they simultaneously viewed scenes while their eye movements were recorded. Because eye movements and visual working memory are closely linked, we anticipated the visual load would interfere with scene-viewing (and vice versa), while the verbal load would not. Surprisingly, both visual and verbal memory loads interfered with scene-viewing behavior, while eye movements during scene-viewing did not significantly interfere with performance on either memory task. These results suggest that a verbal working memory load can interfere with eye movements in a visual task.

Heaviness-brightness correspondence and stimulus-response compatibility

Cross-sensory correspondences can reflect crosstalk between aligned conceptual feature dimensions, though uncertainty remains regarding the identities of all the dimensions involved. It is unclear, for example, if heaviness contributes to correspondences separately from size. Taking steps to dissociate variations in heaviness from variations in size, the question was asked if a heaviness-brightness correspondence will induce a congruity effect during the speeded brightness classification of simple visual stimuli. Participants classified the stimuli according to whether they were brighter or darker than the mid-gray background against which they appeared. They registered their speeded decisions by manipulating (e.g., tapping) the object they were holding in either their left or right hand (e.g., left for bright, right for dark). With these two otherwise identical objects contrasting in their weight, stimuli were classified more quickly when the relative heaviness of the object needing to be manipulated corresponded with the brightness of the stimulus being classified (e.g., the heavier object for a darker stimulus). This novel congruity effect, in the guise of a stimulus-response (S-R) compatibility effect, was induced when heaviness was isolated as an enduring feature of the object needing to be manipulated. It was also undiminished when participants completed a concurrent verbal memory load task, countering claims that the heaviness-brightness correspondence is verbally mediated. Heaviness, alongside size, appears to contribute to cross-sensory correspondences in its own right and in a manner confirming the far-reaching influence of correspondences, extending here to the fluency with which people communicate simple ideas by manipulating a hand-held object.

The role of working memory for syntactic formulation in language production.

Four picture-description experiments investigated if syntactic formulation in language production can proceed with only minimal working memory involvement. Experiments 1-3 compared the initiation latencies, utterance durations, and errors for syntactically simpler picture descriptions (adjective-noun phrases, e.g., the red book) to those of more complex descriptions (relative clauses, e.g., the book that is red). In Experiment 4, the syntactically more complex descriptions were also lexically more complex (e.g., the book and the car vs. the book). Simpler and more complex descriptions were produced under verbal memory load consisting of 2 or 4 unrelated nouns, or under no load. Across experiments, load actually made production more efficient (as manifested in shorter latencies, shorter durations or both), and sped up the durations of relative clauses more than those of adjective-noun phrases. The only evidence for disproportional disruption of more complex descriptions by load was a greater increase of production errors for these descriptions than for simpler descriptions under load in Experiments 2 and 4. We thus conclude that syntactic formulation in production (for certain constructions or in certain situations) can proceed with minimal working memory involvement. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

When does conscious memory become dependent on the hippocampus? The role of memory load and the differential relevance of left hippocampal integrity for short- and long-term aspects of verbal memory performance.

Supraspan list learning tests are sensitive measures used to assess temporal lobe dysfunction. Most frequently employed is the Rey Auditory Verbal Learning and Memory Test (RAVLT). The test's structure is determined by a short- and long-term memory component. During the first of five learning trials, the short-term memory component is the highest and steadily decreases over the following trials, while the long-term memory component concurrently increases and reaches its maximum at the delayed recall after a retention interval of 30min. The study aimed to test the hypothesis that the functional relevance of left hippocampal integrityfor conscious memory rises along with the increasing degree of the long-term memory component. Moreover, we investigated whether classical measures of short-term and working memory are also dependent on the hippocampus. The analysis was based on 37 adult patients who had undergone surgery for left mesial temporal lobe epilepsy. Neuronal cell densities of the resected left hippocampus were correlated with the presurgical memory performance across trials of the VLMT (the German RAVLT) and with digit span and working memory capacity (WMS-R). Whereas digit span and working memory capacity were not related to hippocampal cell counts, there was a significant correlation between left hippocampal integrity and VLMT memory performance, already regarding the first supraspan learning trial. Correlations steadily increased during the learning course. The highest correlation was seen regarding the delayed free recall. The results indicate an increasing correspondence between the integrity of the left hippocampus and verbal memory with an increasing long-term memory component. Immediate recall of verbal material became already dependent on left hippocampal integrity when the verbal memory load exceeded the memory span (supraspan list learning), while classical span measures that assess verbal short-term and working memory were not affected by left hippocampal pathology.

Writing abilities and the role of working memory in children with symptoms of attention deficit and hyperactivity disorder

ABSTRACTThe writing abilities of children with ADHD symptoms were examined in a simple dictation task, and then in two conditions with concurrent verbal or visuospatial working memory (WM) loads. The children with ADHD symptoms generally made more spelling mistakes than controls, and the concurrent loads impaired their performance, but with partly different effects. The concurrent verbal WM task prompted an increase in the phonological errors, while the concurrent visuospatial WM task prompted more non-phonological errors, matching the Italian phonology, but not the Italian orthography. In the ADHD group, the children proving better able to cope with a concurrent verbal WM load had a better spelling performance too. The ADHD and control groups had a similar handwriting speed, but the former group’s writing quality was poorer. Our results suggest that WM supports writing skills, and that children with ADHD symptoms have general writing difficulties, but strength in coping with concurrent verbal information may support their spelling performance.

Impact of Spatial and Verbal Short-Term Memory Load on Auditory Spatial Attention Gradients.

Short-term memory load can impair attentional control, but prior work shows that the extent of the effect ranges from being very general to very specific. One factor for the mixed results may be reliance on point estimates of memory load effects on attention. Here we used auditory attention gradients as an analog measure to map-out the impact of short-term memory load over space. Verbal or spatial information was maintained during an auditory spatial attention task and compared to no-load. Stimuli were presented from five virtual locations in the frontal azimuth plane, and subjects focused on the midline. Reaction times progressively increased for lateral stimuli, indicating an attention gradient. Spatial load further slowed responses at lateral locations, particularly in the left hemispace, but had little effect at midline. Verbal memory load had no (Experiment 1), or a minimal (Experiment 2) influence on reaction times. Spatial and verbal load increased switch costs between memory encoding and attention tasks relative to the no load condition. The findings show that short-term memory influences the distribution of auditory attention over space; and that the specific pattern depends on the type of information in short-term memory.

Can the Mini-Mental State Examination Predict Capacity to Consent to Treatment?

This study examines the relationship between capacity to consent to treatment as measured by the MacArthur Competence Assessment Tool for Treatment (MacCAT-T) and severity of cognitive impairment as measured with the Mini-Mental State Examination (MMSE). It also looks at the role of verbal retrieval in this relationship. We hypothesized that the often-quoted correlation between the MacCAT-T and the MMSE lies mainly in the joint dependence on verbal retrieval ability. Potential subjects were recruited from memory clinics, senior citizen meeting places, and a university program for seniors. Data of 149 people over 54 years, 49 of whom had been diagnosed with Alzheimer’s disease or mixed dementia, were used. The relationship between capacity to consent to treatment, verbal retrieval, and MMSE was examined using a structural equation modeling framework. The findings suggest that verbal retrieval is a confounding method factor. In the informed consent process for people with dementia, verbal memory loads should be minimized to provide a more valid measure of their capacity to consent to treatment.

Asymmetric cross-domain interference between two working memory tasks: Implications for models of working memory

Abstract Observations of higher dual-task costs for within-domain than cross-domain task combinations constitute classic evidence for multi-component models of working memory (e.g., Baddeley, 1986 , Logie, 2011 ). However, we report an asymmetric pattern of interference between verbal and visual–spatial tasks, such that imposing a verbal memory load provokes graded decreases in visual memory performance, but imposing a visual memory load does not much affect verbal memory performance. Across multiple experiments, we verify that this pattern cannot adequately be explained as a mere byproduct of stimulus recoding or strategic preference. Current working memory models do not predict this persistent finding, thus a change in ongoing debate about relationships between attention and maintenance of verbal and visual mental representations is necessary.

Working memory loads affect location-based negative priming differently than inhibition of return

Although some experimental research suggests that location-based negative priming (L-NP; slowed responding to stimuli presented at previously ignored locations) and inhibition of return (IOR; slowed responding to stimuli presented at previously attended locations) are caused by a common underlying mechanism, there is reason to doubt this claim. Evidence for this is briefly reviewed and four experiments are reported where L-NP and IOR are examined under different memory load conditions. We found that L-NP remained intact under a visual-spatial and verbal memory load (Experiments 1, 2, and 4) in accordance with predictions, but a visual-spatial memory load eliminated IOR (Experiment 3). These data support claims that IOR is dependent on visual-spatial memory and are the first to establish that L-NP, unlike identity-based negative priming (I-NP), is not reduced with a memory load. These data bolster claims that at least one of the processes that contribute to L-NP differs from the processes that produce IOR.

Do you see what I’m singing? Visuospatial movement biases pitch perception

The nature of the connection between musical and spatial processing is controversial. While pitch may be described in spatial terms such as “high” or “low”, it is unclear whether pitch and space are associated but separate dimensions or whether they share representational and processing resources. In the present study, we asked participants to judge whether a target vocal note was the same as (or different from) a preceding cue note. Importantly, target trials were presented as video clips where a singer sometimes gestured upward or downward while singing that target note, thus providing an alternative, concurrent source of spatial information. Our results show that pitch discrimination was significantly biased by the spatial movement in gesture, such that downward gestures made notes seem lower in pitch than they really were, and upward gestures made notes seem higher in pitch. These effects were eliminated by spatial memory load but preserved under verbal memory load conditions. Together, our findings suggest that pitch and space have a shared representation such that the mental representation of pitch is audiospatial in nature.

Visuospatial and verbal working memory load: effects on visuospatial vigilance

In this study, we examined the impact of concurrent verbal and visuospatial working memory demands on performance of a visuospatial successive target detection task. Three hundred and four participants performed a visuospatial vigilance task while simultaneously performing either a spatial or verbal working memory task that either required a memory load during the vigil or did not require a memory load during the vigil. Perceptual sensitivity A' to vigilance target stimuli was reduced by concurrent memory load, both verbal and visuospatial. The decline in perceptual sensitivity to vigilance targets, the vigilance decrement, was steeper for a visuospatial memory task than a verbal memory task, regardless of concurrent memory load. Memory performance after vigilance detection trials was much lower for visuospatial than verbal items, even though memory performance before vigilance detection trials was higher for visuospatial than verbal items. Together, this indicates increased interference when a visuospatial vigilance task is paired with a visuospatial memory task, than when paired with a verbal memory task. Overall, the visuospatial and verbal working memory loads both impacted vigilance target detection, suggesting utilization of common executive resources. There may, however, be domain specific interference, and this may be exacerbated for two visuospatial tasks.

A dual task priming investigation of right hemisphere inhibition for people with left hemisphere lesions

BackgroundDuring normal semantic processing, the left hemisphere (LH) is suggested to restrict right hemisphere (RH) performance via interhemispheric suppression. However, a lesion in the LH or the use of concurrent tasks to overload the LH's attentional resource balance has been reported to result in RH disinhibition with subsequent improvements in RH performance. The current study examines variations in RH semantic processing in the context of unilateral LH lesions and the manipulation of the interhemispheric processing resource balance, in order to explore the relevance of RH disinhibition to hemispheric contributions to semantic processing following a unilateral LH lesion.MethodsRH disinhibition was examined for nine participants with a single LH lesion and 13 matched controls using the dual task paradigm. Hemispheric performance on a divided visual field lexical decision semantic priming task was compared over three verbal memory load conditions, of zero-, two- and six-words. Related stimuli consisted of categorically related, associatively related, and categorically and associatively related prime-target pairs. Response time and accuracy data were recorded and analyzed using linear mixed model analysis, and planned contrasts were performed to compare priming effects in both visual fields, for each of the memory load conditions.ResultsControl participants exhibited significant bilateral visual field priming for all related conditions (p < .05), and a LH advantage over all three memory load conditions. Participants with LH lesions exhibited an improvement in RH priming performance as memory load increased, with priming for the categorically related condition occurring only in the 2- and 6-word memory conditions. RH disinhibition was also reflected for the LH damage (LHD) group by the removal of the LH performance advantage following the introduction of the memory load conditions.ConclusionsThe results from the control group are consistent with suggestions of an age related hemispheric asymmetry reduction and indicate that in healthy aging compensatory bilateral activation may reduce the impact of inhibition. In comparison, the results for the LHD group indicate that following a LH lesion RH semantic processing can be manipulated and enhanced by the introduction of a verbal memory task designed to engage LH resources and allow disinhibition of RH processing.

Working memory load and the vigilance decrement

In this study, we examined the impact of concurrent verbal and spatial working memory demands on performance on an alpha-numeric successive target detection task. Seven hundred and forty-five participants performed a target detection task while simultaneously performing either a spatial or a verbal working memory task or they performed matched no-memory control tasks. The vigilance decrement, both an increase in target detection response times and a decrease in perceptual sensitivity A' to target stimuli over time, was exacerbated by concurrent working memory load. The spatial and verbal working memory loads both impacted vigilance performance suggesting utilization of common executive resources. Overall, these results support the view that the vigilance decrement results from high cognitive resource demands (e.g., hard work), not from cognitive under-load (e.g., boredom or mindlessness).

Differences in Mental Rotation Strategies for Native Speakers of Chinese and English and How They Vary As a Function of Sex and College Major

In this study we examine how native language, sex, and college major interact to influence accuracy and preferred strategy when performing mental rotation (MR). Native monolingual Chinese and English speakers rotated 3-D shapes while maintaining a concurrent verbal or spatial memory load. For English speakers, male physical science majors were more accurate than social science majors and employed a spatial/holistic strategy; male social science majors used a verbal/analytic strategy. Regardless of college major, English-speaking females were not consistent in MR strategy. A small overall advantage in accuracy was found for Chinese speakers, and both male and female Chinese-speaking physical science majors relied on a combined spatial/holistic and verbal/analytic strategy; Chinese-speaking social science majors did not show a strategy preference. Our results suggest that acquiring a logographic language like Chinese may heighten spatial ability and bias one toward a spatial/holistic MR strategy.

How verbal memory loads consume attention

According to a traditional assumption about working memory, participants retain a series of verbal items for immediate recall using covert verbal rehearsal, without much need for attention. We reassessed this assumption by imposing a speeded, nonverbal choice reaction time (CRT) task following the presentation of each digit in a list to be recalled. When the memory load surpassed a few items, performance on the speeded CRT task became increasingly impaired. This CRT task impairment depended only on attention-related components of working memory; it was not alleviated by the presence of an auditory memory trace that automatically helped the recall of items at the ends of spoken lists. We suggest that attention-demanding refreshing of verbal stimuli occurs along with any covert rehearsal.

Stronger inference with direct manipulation of brain function

At an early stage in our educations we have all learned that statistical significance need not imply functional significance, and, relatedly, that correlation does not imply causation. Despite these caveats, it is indisputable that cognitive neuroscience has learned a great deal about the neural bases of behaviour via the fundamentally correlative methods of functional neuroimaging. This is particularly true in cases when a carefully controlled neuroimaging study can illustrate functional properties of a brain region whose necessity for a particular aspect of behaviour has been established with lesion data. There can arise, however, situations in which two different neuroimaging studies (and indeed, as we will review here, two different analyses of the same data set) produce mutually incompatible results, thereby leaving ambiguous the nature of the structure-function mapping that the experiments were designed to address. This is a situation in which the ability to locally alter brain function in a prospective manner can be particularly useful. The aspect of cognition that is at issue in this commentary is the short-term retention (STR, a.k.a. “storage” or “maintenance”) of information that is required by tests of short-term and working memory. One way to operationalise this construct is to vary the number of items that must be retained on different trials. Prompted by a review of studies that manipulated verbal memory load in this way, we applied two different analyses to the data from a sample of 24 subjects retaining 2 vs. 5 letters in a (7 sec) delayed-recognition task during functional magnetic resonance imaging (fMRI): a spatially normalized group-average (SNGA) analysis; and singlesubject (SS) analyses that treated each subject’s data as an individual case (Feredoes and Postle, 2007). The SNGA analysis revealed a region in left posterior middle frontal gyrus (MFG) of the prefrontal cortex (PFC), near the border of Brodmann Areas 9 and 6, that was reliably sensitive to the manipulation of load, and, therefore, a candidate locus for the STR of verbal information. (This also replicated the findings of previous studies that had also used SNGA analyses (e.g., Narayanan et al., 2005).) The SS analyses, in contrast, produced results that were topographically highly variable across subjects and, notably, did not include the left posterior MFG in any subject. Instead, the regions demonstrating load effects were best summarized as occurring in left posterior perisylvian cortex in the majority of subjects. These results prompted us to address the obvious question of which brain regions, those identified by the SNGA or the SS analyses, contributed more importantly to the STR of information in our task? (Although it was empirically plausible that the two sets of regions could make functionally comparable contributions, the two sets of results were difficult to reconcile theoretically (Postle, 2006).) To address this question, we performed a second study that would

Familiarity enhances visual working memory for faces.

Although it is intuitive that familiarity with complex visual objects should aid their preservation in visual working memory (WM), empirical evidence for this is lacking. This study used a conventional change-detection procedure to assess visual WM for unfamiliar and famous faces in healthy adults. Across experiments, faces were upright or inverted and a low- or high-load concurrent verbal WM task was administered to suppress contribution from verbal WM. Even with a high verbal memory load, visual WM performance was significantly better and capacity estimated as significantly greater for famous versus unfamiliar faces. Face inversion abolished this effect. Thus, neither strategic, explicit support from verbal WM nor low-level feature processing easily accounts for the observed benefit of high familiarity for visual WM. These results demonstrate that storage of items in visual WM can be enhanced if robust visual representations of them already exist in long-term memory.