Serial Order Short-term Memory Research Articles

Heterogeneity of short-term memory deficits in children with dyslexia.

Many studies have highlighted short-term memory (STM) impairment in dyslexic individuals. Several studies showed deficits for both item and serial order aspects of verbal STM in dyslexic individuals. These group-based studies, however, do not inform us about the prevalence of these deficits and, importantly, their potential heterogeneity at the individual level. The present study examined both group-level and individual STM profiles in dyslexic and age-matched non-dyslexic children. While confirming previous group-based results of both item and serial order STM deficits, individual analyses indicated two distinct profiles: one profile was associated with verbal item STM and phonological impairment while another profile showed selective serial STM deficits in both verbal and visual domains. Our results highlight the need for practitioners to consider the heterogeneous nature of STM impairment in dyslexia and to adapt STM and reading treatment strategies accordingly.

Language acquisition of early sequentially bilingual children is moderated by short-term memory for order in developmental language disorder: Findings from the HelSLI study.

The role of domain-general short-term memory (STM) in language development remains controversial. A previous finding from the HelSLI study on children with developmental language disorder (DLD) suggested that not only verbal but also non-verbal STM for temporal order is related to language acquisition in monolingual children with DLD. To investigate if a similar relationship could be replicated in a sample of sequentially bilingual children with DLD. In addition to the effect of age, the effect of cumulative second language (L2) exposure was studied. Sixty-one 4-6-year-old bilingual children with DLD and 63 typically developing (TD) bilingual children participated in a cross-sectional study conducted in their L2. Children completed novel game-like tests of visual and auditory non-verbal serial STM, as well as tests of cognitive functioning and language. Interactions of STM for order with age and exposure to L2 (Finnish) were explored as explanatory variables. First, the improvement of non-verbal serial STM with age was faster in sequentially bilingual TD children than in bilingual children with DLD. A similar effect was observed for L2 exposure. However, when both age and exposure were considered simultaneously, only age was related to the differential growth of non-verbal STM for order in the groups. Second, only in children with DLD was better non-verbal serial STM capacity related to an improvement in language scores with age and exposure. The results suggest that, as previously found in Finnish monolingual children, domain-general serial STM processing is also compromised in bilingual children with DLD. Further, similar to the monolingual findings, better non-verbal serial STM was associated with greater language improvement with age and exposure, but only in children with DLD, in the age range studied here. Thus, in clinical settings, assessing non-verbal serial STM of bilingual children could improve the detection of DLD and understanding of its non-linguistic symptoms. What is already known on the subject Both phonological and non-verbal STM have been associated with DLD in monolingual and sequentially bilingual children. Monolingual children with DLD have also shown slower non-verbal serial STM development than TD children. What this study adds to existing knowledge Sequentially bilingual TD children's non-verbal serial STM improves more between ages 4 and 7 years than that of their peers with DLD, replicating a finding for monolingual children with DLD. Better non-verbal serial STM was especially associated with early receptive language development in sequentially bilingual children with DLD. L2 exposure showed largely comparable effects with age. These results support the hypothesis that a domain-general serial STM deficit is linked to DLD. What are the potential or actual clinical implications of this work? Non-verbal assessment of STM for serial order in sequentially bilingual children with DLD could benefit the development of better tailored therapeutic interventions.

Short-Term Memory for Serial Order Moderates Aspects of Language Acquisition in Children With Developmental Language Disorder: Findings From the HelSLI Study.

Previous studies of verbal short-term memory (STM) indicate that STM for serial order may be linked to language development and developmental language disorder (DLD). To clarify whether a domain-general mechanism is impaired in DLD, we studied the relations between age, non-verbal serial STM, and language competence (expressive language, receptive language, and language reasoning). We hypothesized that non-verbal serial STM differences between groups of children with DLD and typically developing (TD) children are linked to their language acquisition differences. Fifty-one children with DLD and sixty-six TD children participated as part of the HelSLI project in this cross-sectional study. The children were 4–6-year-old monolingual native Finnish speakers. They completed several tests of language and cognitive functioning, as well as new game-like tests of visual and auditory non-verbal serial STM. We used regression analyses to examine how serial STM moderates the effect of age on language. A non-verbal composite measure of serial visual and auditory STM moderated cross-sectional development of receptive language in the children with DLD. This moderation was not observed in the TD children. However, we found more rapid cross-sectional development of non-verbal serial STM in the TD children than in the children with DLD. The results suggest that children with DLD may be more likely to have compromised general serial STM processing and that superior non-verbal serial STM may be associated with better language acquisition in children with DLD.

Do serial order short-term memory and long-term learning abilities predict spelling skills in school-age children?

Compared to most human language abilities, the cognitive mechanisms underlying spelling have not been as intensively investigated as reading and therefore remain to this day less well understood. The current study aims to address this shortcoming by investigating the contribution of serial order short-term memory (STM) and long-term learning (LTL) abilities to emerging spelling skills. Indeed, although there are several reasons to assume associations between serial order memory and spelling abilities, this relationship has hardly been investigated empirically. In this study, we hypothesized that serial order STM plays an important role in spelling novel words, for which children are supposed to rely on a sequential nonlexical spelling procedure. Serial order LTL was hypothesized to be involved in the creation of more stable orthographic representations allowing children to spell (regular and irregular) words by using a lexical spelling strategy based on the direct access to orthographic representations stored in long-term memory. To assess these hypotheses, we conducted a longitudinal study in which we tested a sample of 116 French-speaking children at first grade and two years later at third grade of primary school. At first grade, we administered tasks that were specifically designed to maximize STM and LTL abilities for serial order information. At third grade, we assessed spelling abilities using irregular word, regular word, and pseudoword writing-to-dictation tasks. Bayesian regression analyses showed that pseudoword, but also irregular word spelling was best predicted by serial order STM, while regular word spelling was similarly predicted by both serial order STM and LTL.

A Dynamic Method, Analysis, and Model of Short-Term Memory for Serial Order with Clinical Applications

This study examined the robustness of a traditional memory task when moved out of controlled traditional settings. A letter recall task was designed to be self-administered via a smart-device which assessed recall by participants’ writing their responses on the device. This enabled collection of both the letter recalled and the timing of this recall such that the temporal dynamics could be examined. Participants were patients with mental illness (n=71) and healthy volunteers (n=103). Temporal dynamics were examined using a new mechanism that measured memory retrieval time precisely. Data were analyzed for accuracy, time and their relationships. The classic memory phenomena and associated effects were replicated. In terms of temporal dynamics, this is the first demonstration of primacy and recency effects in time domain variables, as well as phonological similarity effects as evident by the inverted U-shaped curves in time. The speed of short-term memory processes affects accuracy, error types and timing. The robustness of these memory effects and new approach to temporal dynamics suggest this framework may be suitable for clinical applications, notably for the long-term monitoring of cognition in patients with mental illness.

The contribution of serial order short-term memory and long-term learning to reading acquisition: A longitudinal study.

There is increasing evidence for an association between both serial order short-term memory (STM) and the long-term learning (LTL) of serial order information and reading abilities. In this developmental study, we examined the hypothesis that STM for serial order supports online grapheme-to-phoneme conversion processes during the initial stages of reading acquisition, whereas the LTL of serial order serves reading abilities at later stages, when reading starts to rely on more stable, long-term orthographic representations. We followed a sample of 116 French-speaking children from first (Time 1 [T1]) grade of primary school through second (Time 2 [T2]) and third (Time 3 [T3]) grade. Their serial order STM and LTL abilities as well as their reading abilities were assessed. Overall, we observed that early reading abilities were only predicted by serial order STM performance, while more advanced reading abilities were predicted by both serial order STM and LTL performance. These results point toward a predictive role of serial order memory performance in reading acquisition and suggest that serial order STM and LTL support reading at different stages of acquisition. We further discuss our findings in the light of advancing knowledge about the relationship between memory and reading. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The influence of rhythm on short-term memory for serial order.

In the field of verbal short-term memory (STM), numerous theoretical models have been proposed to explain how serial order information is processed and represented. Evidence suggests that serial order is represented through associations between items and a varying contextual signal coding the position of each item in a sequence, but the nature of this contextual signal is still a matter of debate (i.e., event-based vs. time-based varying signal). According to event-based models of serial order, the contextual signal coding serial order is not sensitive to temporal manipulations, as it is the case in irregularly timed sequences. Up to now, the study of the temporal factors influencing serial order STM has been limited to temporal grouping and temporal isolation effects. The goal of the present study is to specify in more detail the role played by temporal factors in serial order STM tasks. To accomplish this, we compared recall performance and error patterns for sequences presenting items at a regular or an irregular and unpredictable timing in three experiments. The results showed that irregular timing does not affect serial recall nor the pattern of errors. These data clearly favour the view that serial order in verbal STM is represented with event-based rather than time-based codes.

The influence of age, schooling, literacy, and socioeconomic status on serial-order memory

We aimed at investigating whether formal schooling and literacy favor progress in verbal serial-order short-term memory (STM). In Experiment 1, we presented children varying on age, school level, and socioeconomic background with a serial-order reconstruction task and observed differences related to both age and school level. Two subsequent experiments aimed at separating schooling- and literacy-related effects from age-related ones. In Experiment 2 we compared, on the one hand, performance of children of similar age but different school levels and, on the other hand, performance of children of same school level but different ages. We observed a schooling effect but no age effect on serial-order reconstruction: the youngest first-graders outperformed age-matched kindergartners but performed similarly as older first-graders of the same literacy level. Furthermore, children’s literacy abilities were strongly correlated to their serial-order reconstruction performance, even after controlling for the effects of non-verbal reasoning and vocabulary. In Experiment 3 we examined low socio-economic background adults presenting varying (correlated) levels of schooling and literacy: some had attended school in childhood for only a few years and were either illiterate or very poor readers, whereas others had attended school for at least 12 years. In addition to serial-order memory, item STM was assessed by a delayed single nonword repetition task. The groups differed on both STM tasks, which both correlated with their literacy abilities. Thus, literacy and schooling do not impact only order memory, but more generally verbal STM. Moreover, comparison between the adults’ and children’s data strongly suggests that it is schooling and/or literacy rather than age per se that matters for serial-order memory.

The relationship of domain-general serial order memory and reading ability in school children with and without dyslexia

Recent evidence suggests that reading development when learning alphabetic languages is related to the underlying cognitive ability to maintain the serial order of information in short-term memory (STM). However, it remains unclear at which time point in reading development serial order STM is most important. Here, we established a crucial link between the reading development of primary school children and their serial order STM performance for both verbal and nonverbal materials. In a large cohort study of 113 Italian-speaking elementary school children in Grades 1–4, we investigated this relationship by implementing a novel double-probe design. In Experiment 1, we found that serial order STM performance was related to children’s reading abilities, especially in Grades 2 and 3, corresponding to the training phase of grapheme–phoneme decoding skills. In Experiment 2, we assessed children with developmental dyslexia (DD) and found that their serial order STM performance was significantly lower than that of chronological age-matched controls (CA). It also differed from that of reading age-matched controls when accounting for individual reading performance. Furthermore, the CA group displayed an implicit serial order facilitation for item memory, whereas this implicit recruitment of serial order abilities was completely absent in children with DD. Our results suggest that the domain-general cognitive ability to maintain the serial order of information interacts with the development of reading competency, especially during a middle training phase of word reading, and this particular relationship is markedly impaired in children with DD.

Supplemental Material for The Contribution of Serial Order Short-Term Memory and Long-Term Learning to Reading Acquisition: A Longitudinal Study

Supplemental Material for The Contribution of Serial Order Short-Term Memory and Long-Term Learning to Reading Acquisition: A Longitudinal Study

Short-and long-term memory determinants of novel word form learning

It is widely assumed that a strong positive link exists between memory and vocabulary development. Nevertheless, the exact involvement of short-term memory (STM) and long-term memory (LTM) is poorly understood. STM for serial order information is argued to play a crucial role in temporarily maintaining and refreshing the order of phonemes representing novel word forms. LTM for serial order information, in contrast, is involved in the consolidation of phoneme sequences into unitary word form representations. Here, we tested 131 6-year-old children on tasks that targeted STM for serial order versus item information, on a Hebb repetition task targeting long-term serial order learning, and on a paired-associate novel word learning task. Bayesian analyses revealed a strong correlation between STM for serial order information, and both the initial and final stages of word form learning. LTM was associated with the final stages of word form learning. These findings are discussed in light of existing theories about the role of memory in language.

Temporal grouping effects in musical short-term memory

ABSTRACTRecent theoretical accounts of verbal and visuo-spatial short-term memory (STM) have proposed the existence of domain-general mechanisms for the maintenance of serial order information. These accounts are based on the observation of similar behavioural effects across several modalities, such as temporal grouping effects. Across two experiments, the present study aimed at extending these findings, by exploring a STM modality that has received little interest so far, STM for musical information. Given its inherent rhythmic, temporal and serial organisation, the musical domain is of interest for investigating serial order STM processes such as temporal grouping. In Experiment 1, the data did not allow to determine the presence or the absence of temporal grouping effects. In Experiment 2, we observed that temporal grouping of tone sequences during encoding improves short-term recognition for serially presented probe tones. Furthermore, the serial position curves included micro-primacy and micro-recency effects, which are the hallmark characteristic of temporal grouping. Our results suggest that the encoding of serial order information in musical STM may be supported by temporal positional coding mechanisms similar to those reported in the verbal domain.

Separate Serial Order Short-term Memory Systems: A Case Series Approach

Separate Serial Order Short-term Memory Systems: A Case Series Approach

Domain-Generality of Timing-Based Serial Order Processes in Short-Term Memory: New Insights from Musical and Verbal Domains.

Several models in the verbal domain of short-term memory (STM) consider a dissociation between item and order processing. This view is supported by data demonstrating that different types of time-based interference have a greater effect on memory for the order of to-be-remembered items than on memory for the items themselves. The present study investigated the domain-generality of the item versus serial order dissociation by comparing the differential effects of time-based interfering tasks, such as rhythmic interference and articulatory suppression, on item and order processing in verbal and musical STM domains. In Experiment 1, participants had to maintain sequences of verbal or musical information in STM, followed by a probe sequence, this under different conditions of interference (no-interference, rhythmic interference, articulatory suppression). They were required to decide whether all items of the probe list matched those of the memory list (item condition) or whether the order of the items in the probe sequence matched the order in the memory list (order condition). In Experiment 2, participants performed a serial order probe recognition task for verbal and musical sequences ensuring sequential maintenance processes, under no-interference or rhythmic interference conditions. For Experiment 1, serial order recognition was not significantly more impacted by interfering tasks than was item recognition, this for both verbal and musical domains. For Experiment 2, we observed selective interference of the rhythmic interference condition on both musical and verbal order STM tasks. Overall, the results suggest a similar and selective sensitivity to time-based interference for serial order STM in verbal and musical domains, but only when the STM tasks ensure sequential maintenance processes.

Functional Alterations in Order Short-Term Memory Networks in Adults With Dyslexia

Dyslexia is characterized not only by reading impairment but also by short-term memory (STM) deficits, and this particularly for the retention of serial order information. Here, we explored the functional neural correlates associated with serial order STM performance of adults with dyslexia for verbal and visual STM tasks. Relative to a group of age-matched controls, the dyslexic group showed abnormal activation in a network associated with order STM encompassing the right intraparietal and superior frontal sulcus, and this for both verbal and visual order STM conditions. This study highlights long-lasting alterations in non-language neural substrates and processes in dyslexia.

The heterogeneity of verbal short-term memory impairment in aphasia

Verbal short-term memory (STM) impairment represents a frequent and long-lasting deficit in aphasia, and it will prevent patients from recovering fully functional language abilities. The aim of this study was to obtain a more precise understanding of the nature of verbal STM impairment in aphasia, by determining whether verbal STM impairment is merely a consequence of underlying language impairment, as suggested by linguistic accounts of verbal STM, or whether verbal STM impairment reflects an additional, specific deficit. We investigated this question by contrasting item-based STM measures, supposed to depend strongly upon language activation, and order-based STM measures, supposed to reflect the operation of specific, serial order maintenance mechanisms, in a sample of patients with single-word processing deficits at the phonological and/or lexical level. A group-level analysis showed robust impairment for both item and serial order STM aspects in the aphasic group relative to an age-matched control group. An analysis of individual profiles revealed an important heterogeneity of verbal STM profiles, with patients presenting either selective item STM deficits, selective order STM deficits, generalized item and serial order STM deficits or no significant STM impairment. Item but not serial order STM impairment correlated with the severity of phonological impairment. These results disconfirm a strong version of the linguistic account of verbal STM impairment in aphasia, by showing variable impairment to both item and serial order processing aspects of verbal STM.

Order short-term memory is not impaired in dyslexia and does not affect orthographic learning.

This article reports two studies that investigate short-term memory (STM) deficits in dyslexic children and explores the relationship between STM and reading acquisition. In the first experiment, 36 dyslexic children and 61 control children performed an item STM task and a serial order STM task. The results of this experiment show that dyslexic children do not suffer from a specific serial order STM deficit. In addition, the results demonstrate that phonological processing skills are as closely related to both item STM and serial order STM. However, non-verbal intelligence was more strongly involved in serial order STM than in item STM. In the second experiment, the same two STM tasks were administered and reading acquisition was assessed by measuring orthographic learning in a group of 188 children. The results of this study show that orthographic learning is exclusively related to item STM and not to order STM. It is concluded that serial order STM is not the right place to look for a causal explanation of reading disability, nor for differences in word reading acquisition.

Short-term memory development: Differences in serial position curves between age groups and latent classes

In studies on the development of cognitive processes, children are often grouped based on their ages before analyzing the data. After the analysis, the differences between age groups are interpreted as developmental differences. We argue that this approach is problematic because the variance in cognitive performance within an age group is considered to be measurement error. However, if a part of this variance is systematic, it can provide very useful information about the cognitive processes used by some children of a certain age but not others. In the current study, we presented 210 children aged 5 to 12years with serial order short-term memory tasks. First we analyze our data according to the approach using age groups, and then we apply latent class analysis to form latent classes of children based on their performance instead of their ages. We display the results of the age groups and the latent classes in terms of serial position curves, and we discuss the differences in results. Our findings show that there are considerable differences in performance between the age groups and the latent classes. We interpret our findings as indicating that the latent class analysis yielded a much more meaningful way of grouping children in terms of cognitive processes than the a priori grouping of children based on their ages.

Common Neural Substrates for Ordinal Representation in Short-Term Memory, Numerical and Alphabetical Cognition

The representation and maintenance of serial order information is one of the main functions of verbal short-term memory (STM) but its neural correlates remain poorly understood. We show here that the neural substrates allowing for coding of order information in STM are shared with those supporting ordinal processing in the numerical and alphabetical domains. We designed an fMRI experiment determining the neural substrates sensitive to ordinal distance effects in numerical judgment, alphabetical judgment and serial order STM tasks. Null conjunction analyses for parametric ordinal distance effects showed a common involvement of the horizontal segment of the left intraparietal sulcus over the three tasks; in addition, right intraparietal sulcus involvement was also observed for ordinal distance effects in the STM and numerical judgment tasks. These findings demonstrate that shared neural correlates in the intraparietal cortex support processing of order information in verbal STM, number and alphabetical domains, and suggest the existence of domain general, potentially ordinal, comparison processes supported by the left intraparietal sulcus.

Short-term memory for order but not for item information is impaired in developmental dyslexia

Recent findings suggest that people with dyslexia experience difficulties with the learning of serial order information during the transition from short- to long-term memory (Szmalec et al. Journal of Experimental Psychology: Learning, Memory, & Cognition 37(5): 1270-1279, 2011). At the same time, models of short-term memory increasingly incorporate a distinction of order and item processing (Majerus et al. Cognition 107: 395-419, 2008). The current study is aimed to investigate whether serial order processing deficiencies in dyslexia can be traced back to a selective impairment of short-term memory for serial order and whether this impairment also affects processing beyond the verbal domain. A sample of 26 adults with dyslexia and a group of age and IQ-matched controls participated in a 2 × 2 × 2 experiment in which we assessed short-term recognition performance for order and item information, using both verbal and nonverbal material. Our findings indicate that, irrespective of the type of material, participants with dyslexia recalled the individual items with the same accuracy as the matched control group, whereas the ability to recognize the serial order in which those items were presented appeared to be affected in the dyslexia group. We conclude that dyslexia is characterized by a selective impairment of short-term memory for serial order, but not for item information, and discuss the integration of these findings into current theoretical views on dyslexia and its associated dysfunctions.