Phonological Store Research Articles

The phonological store of working memory: A critique and an alternative, perceptual-motor, approach to verbal short-term memory.

A key quality of a good theory is its fruitfulness, one measure of which might be the degree to which it compels researchers to test it, refine it, or offer alternative explanations of the same empirical data. Perhaps the most fruitful element of Baddeley and Hitch's (1974) Working Memory framework has been the concept of a short-term phonological store, a discrete cognitive module dedicated to the passive storage of verbal material that is architecturally fractionated from perceptual, language, and articulatory systems. This review discusses how the phonological store construct has served as the main theoretical springboard for an alternative perceptual-motor approach in which serial-recall performance reflects the opportunistic co-opting of the articulatory-planning system and, when auditory material is involved, the products of obligatory auditory perceptual organisation. It is argued that this approach, which rejects the need to posit a distinct short-term store, provides a better account of the two putative empirical hallmarks of the phonological store-the phonological similarity effect and the irrelevant speech effect-and that it shows promise too in being able to account for nonword repetition and word-form learning, the supposed evolved function of the phonological store. The neuropsychological literature cited as strong additional support for the phonological store concept is also scrutinised through the lens of the perceptual-motor approach for the first time and a tentative articulatory-planning deficit hypothesis for the "short-term memory" patient profile is advanced. Finally, the relation of the perceptual-motor approach to other "emergent-property" accounts of short-term memory is briefly considered.

Articulatory rehearsal and phonological storage in working memory: A replication of Longoni et al. (1993)

Articulatory rehearsal and phonological storage in working memory: A replication of Longoni et al. (1993)

How Is Working Memory Related to Reading Comprehension in Italian Monolingual and Bilingual Children?

This study explored how working memory resources contributed to reading comprehension using tasks that focused on maintenance of verbal information in the phonological store, the interaction between the central executive and the phonological store (WMI), and the storage of bound semantic content in the episodic buffer (immediate narrative memory). We analysed how performance in these tasks was related to text decoding (reading speed and accuracy), listening and reading comprehension. The participants were 62 monolingual and 36 bilingual children (mean age nine years, SD = 9 months) enrolled in the same Italian primary school. Bilingual children were born to immigrant parents and had a long history of exposure to Italian as a second language. The regression analyses showed that reading accuracy and listening comprehension were associated with reading comprehension for monolingual and bilingual children. Two working memory components-WMI and immediate narrative memory-exhibited indirect effects on reading comprehension through reading accuracy and listening comprehension, respectively. Such effects occurred only for monolingual children. We discuss the implications of such findings for text reading and comprehension in monolinguals and bilinguals.

Speech processing and short term memory skills in preschoolers: Evidence from Greek-speaking children with and without speech sound disorders

ABSTRACT Cognitive mechanisms such as short-term memory (STM) are considered to relate to speech development, yet the extent of potential limitations in children with speech sound disorders (SSD) is unknown and the nature of the relationship is debatable. The present paper explores the development of speech input and output processing skills along with STM skills in Greek-speaking children with SSD and typically developing (TD) controls. Potential relationships in performance between tasks that require phonological processing are explored. Participants with SSD aged 5;1–6;2 years (n = 30) and TD controls aged 5;1–5;11 years (n = 100) were monolingual Greek-speaking children. Speech processing skills and phonological storage were assessed as follows: (1) Input processing: a nonword auditory discrimination task was used to assess phoneme discrimination skills. Stimuli comprised 24 pairs of nonwords consisting of the same number of phonemes (2–7 phonemes) and syllables (1–3 syllables). (2) Output processing: a nonword repetition task was used to assess speech production skills. Stimuli comprised 24 nonwords of varying length (2–5 syllables). (3) STM: a task of immediate verbal recall was used to assess phonological storage. Stimuli comprised a chunk of five words; each word (2–4 syllables long) was semantically unrelated to others. The results showed that TD children outperformed children with SSD in all tasks; a significant correlation between performance in nonword repetition and immediate verbal recall was found for TD children. There were no significant correlations between performance on nonword auditory discrimination with nonword repetition or with immediate verbal recall for TD children or children with SSD.

Cerebellar Transcranial Magnetic Stimulation (TMS) Impairs Visual Working Memory.

An increasing body of evidence points to the involvement of the cerebellum in cognition. Specifically, previous studies have shown that the superior and inferior portions of the cerebellum are involved in different verbal working memory (WM) mechanisms as part of two separate cerebro-cerebellar loops for articulatory rehearsal and phonological storage mechanisms. In comparison, our understanding of the involvement of the cerebellum in visual WM remains limited. We have previously shown that performance in verbal WM is disrupted by single-pulse transcranial magnetic stimulation (TMS) of the right superior cerebellum. The present study aimed to expand on this notion by exploring whether the inferior cerebellum is similarly involved in visual WM. Here, we used fMRI-guided, double-pulse TMS to probe the necessity of left superior and left inferior cerebellum in visual WM. We first conducted an fMRI localizer using the Sternberg visual WM task, which yielded targets in left superior and inferior cerebellum. Subsequently, TMS stimulation of these regions at the end of the encoding phase resulted in decreased accuracy in the visual WM task. Differences in the visual WM deficits caused by stimulation of superior and inferior left cerebellum raise the possibility that these regions are involved in different stages of visual WM.

Phonological store and speechreading performance of Chinese students with hearing impairment

ABSTRACT This study presents three experiments to examine the role of the phonological store component of working memory in the speechreading performance of students with hearing impairment (HI) in China. In Experiment 1, 86 high school students with HI completed an immediate serial recall task with four lists of monosyllabic words that differed in phonological and visual similarities. In Experiment 2 and Experiment 3, 40 participants divided into high or low phonological store capacity (PS) and 40 participants divided into high or low visual phonological story capacity (VPS) completed a speechreading test at the word, phrase and sentence levels. Results revealed that (1) immediate serial recall showed effects of phonological and visual similarity and their interaction; (2) there was no significant effect of phonological store capacities on speechreading; and (3) there was a significant effect of visual phonological store capacities on accuracy but not speed of speechreading. These findings point to a general phonological store system for visual orthographic coding and phonological coding that students with HI engage in speechreading in Chinese. It provides evidence for the contention that the visual-based coding has a more direct impact on speechreading performance of Chinese students with HI than the speech-based coding.

Phonological Short-Term Memory Impairment in Children with Down Syndrome

Abstract Background: Children with Down Syndrome commonly suffer from phonological and other language disorders which have been partly attributed to underlying deficit in phonological short term memory. Its evaluation was previously confined to non word repetition and/or forward digit span tasks. Aim of Study: To assess phonological short term memory in children with Down Syndrome with mild degree of intel-lectual disability in comparison with non syndromic children with mild degree of intellectual disability to find out any possible correlation between Down Syndrome and phonolog-ical short term memory deficits through comprehensive eval-uation. Subjects and Methods: This case control study has been conducted on 40 children (20 Down Syndrome children with mild degree of intellectual disability, 20 non syndromic children with mild degree of intellectual disability with matched mental age). All of them underwent psychometric evaluation, audiological evaluation, language evaluation using Arabic version of Modified Preschool Language Scale-4th edition (PLS-4), and Arabic version of Phonological Short Term Memory Test (PSTM). Results: Down Syndrome group scored significantly lower than non syndromic children with mild degree of intellectual disability in all items of phonological short term memory test; digit span, syllable repetition, non sense word repetition, dissimilar word set recall, similar word set recall, total score (p-value 0.000, 0.001, 0.004, 0.000, 0.000, 0.000 respectively) and language test; expressive abilities was lower in Down syndrome children (p-value 0.002) but both groups were equal in their receptive abilities (p-value 0.054). Conclusion: Children with Down Syndrome scored below expected for phonological short term memory and their pho-nological store was extensively impaired.

Effects of phonological loop on inferential processing during Chinese text reading: Evidence from a dual-task paradigm.

The role of working memory (WM) components, such as phonological loop, in online inferential processing has thus far not been empirically examined with a dual-task paradigm. The current study used an online method to examine the effects of the two components of phonological loop-the articulatory rehearsal device and the phonological store device-on online causal inference generation during Chinese text reading. Eighty-five Chinese university students read three-sentence inference and control texts and responded to comprehension questions related to targeted inferences in different reading conditions. The results showed that in the articulatory suppression condition, response times (RTs) for comprehension questions of inference texts were considerably longer, and response errors were significantly higher than those in the normal reading condition, which indicated the effects of the articulatory rehearsal device on readers' online causal inference processes during Chinese text reading. Moreover, RTs for comprehension questions of inference texts in the irrelevant speech condition were significantly shorter than those in the normal reading condition, suggesting effects of the phonological store device on readers' causal inference processes during reading. Taken together, these findings indicate that the articulatory rehearsal device plays an important role in inference processes, but readers allocate more cognitive resources to facilitate the construction of causal relations during text-based inferential comprehension when function of the phonological store device is impaired.

Working Memory Capacities Neurally Dissociate: Evidence from Acute Stroke.

Substantial behavioral evidence implies the existence of separable working memory (WM) components for maintaining phonological and semantic information. In contrast, only a few studies have addressed the neural basis of phonological versus semantic WM using functional neuroimaging and none has used a lesion-symptom mapping (LSM) approach. Here, we address this gap, reporting a multivariate LSM study of phonological and semantic WM for 94 individuals at the acute stage of left hemisphere stroke. Testing at the acute stage avoids issues of brain reorganization and the adoption of patient strategies for task performance. The LSM analyses for each WM component controlled for the other WM component and semantic and phonological knowledge at the single word level. For phonological WM, the regions uncovered included the supramarginal gyrus, argued to be the site of phonological storage, and several cortical and subcortical regions plausibly related to inner rehearsal. For semantic WM, inferior frontal regions and the angular gyrus were uncovered. The findings thus provide converging evidence for separable systems for phonological and semantic WM that are distinguished from the systems supporting long-term knowledge representations in those domains.

Prevocalic t-glottaling across word boundaries in Midland American English

Rates of t-glottaling across word boundaries in both preconsonantal and prevocalic contexts have recently been claimed to be positively correlated with the frequency of occurrence of a given word in preconsonantal contexts (Eddington & Channer, 2010). Words typically followed by consonants have been argued to have their final /t/s glottaled more often than words less frequently followed by consonants. This paper includes a number of ‘internal’ and ‘external’ predictors in a mixed-effects logistic regression model and has two goals: (1) to replicate the positive correlation of the frequency of occurrence of a word in preconsonantal contexts (its ‘contextual frequency’) with its rates of t-glottaling in both preconsonantal and prevocalic contexts postulated by Eddington and Channer (2010), and (2) to quantify the factors influencing the likelihood of t-glottaling across word boundaries in Midland American English. The effect of contextual frequency has been confirmed. This result is argued to support a hybrid view of phonological storage and processing, one including both abstract and exemplar representations. T-glottaling has also been found to be negatively correlated with bigram frequency and speech rate deviation, while positively correlated with young age in female speakers.

The phonological loop: is speech special?

It has been proposed that the maintenance of phonological information in verbal working memory (vWM) is carried by a domain-specific short-term storage center-the phonological loop-which is composed of a phonological store and an articulatory rehearsal system. Several brain regions including the left posterior inferior frontal gyrus (pIFG) and anterior supramarginal gyri (aSMG) are thought to support these processes. However, recent behavioral evidence suggests that verbal and non-verbal auditory information may be processed as part of a unique domain general short-term storage center instead of through specialized subsystems such as the phonological loop. In the current study, we used a single-pulse transcranial magnetic stimulation (TMS)-delayed priming paradigm with speech (syllables) and acoustically complex non-speech sounds (bird songs) to examine whether the pIFG and aSMG are involved in the processing of verbal information or, alternatively, in the processing of any complex auditory information. Our results demonstrate that TMS delivered to both regions had an effect on performance for speech and non-speech stimuli, but the nature of the effect was different. That is, priming was reduced for the speech sounds because TMS facilitated the detection of different but not identical stimuli, and accuracy was decreased for non-speech sounds. Since TMS interfered with both speech and non-speech sounds, these findings support the existence of an auditory short-term storage center located within the dorsal auditory stream.

A cognitive architecture for inner speech

A cognitive architecture for inner speech is presented. It is based on the Standard Model of Mind, integrated with modules for self-talking. Briefly, the working memory of the proposed architecture includes the phonological loop as a component which manages the exchanging information between the phonological store and the articulatory control system. The inner dialogue is modeled as a loop where the phonological store hears the inner voice produced by the hidden articulator process. A central executive module drives the whole system, and contributes to the generation of conscious thoughts by retrieving information from long-term memory. The surface form of thoughts thus emerges by the phonological loop. Once a conscious thought is elicited by inner speech, the perception of new context takes place and then repeating the cognitive loop. A preliminary formalization of some of the described processes by event calculus, and early results of their implementation on the humanoid robot Pepper by SoftBank Robotics are discussed.

Reciprocal relationships between nonword repetition and vocabulary during the preschool years.

The aim of this longitudinal study is to evaluate 3 views on the relationship between nonword repetition and vocabulary: (i) the storage-based view that considers nonword repetition, a measure of phonological storage, as the driving force behind vocabulary development, (ii) the lexical restructuring view that considers improvements in nonword repetition as the result of vocabulary growth, and (iii) the "combined" view that assumes that both storage-based learning and lexical restructuring play a role, resulting in reciprocal relationships between nonword repetition and vocabulary during language development. Data are analyzed from 471 monolingual Dutch children who performed tasks assessing nonword repetition and vocabulary at yearly intervals, from ages 2 to 5. Latent Change Score (LCS) modeling of Item Response Theory-scaled scores was used to investigate the relationships between nonword repetition and vocabulary growth over time. Additionally, the statistical techniques used in earlier work-cross-lagged and latent growth modeling-were applied to see whether the results changed as a function of the analytical technique used. Results from a bivariate LCS model showed positive reciprocal influences from nonword repetition on vocabulary between 2 and 5 years. Such positive cross-influences also emerged from the cross-lagged and latent growth models. Predictive relationships from vocabulary to nonword repetition were stronger than vice versa. These results indicate that both storage-based learning and lexical restructuring play a role in vocabulary learning, at least in early stages of language development, with the clearest support found for lexical restructuring. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Maintaining task set against distraction: The role of working memory in multitasking.

Multitasking, a common feature of everyday life, requires simultaneous maintenance and operation of a range of action-controlling task sets. We attempt to investigate the role of working memory in multitasking by means of the embedded task paradigm. This involves setting up a primary task with a variable task set, which then has to be maintained throughout the performance of a second embedded task with a fixed task set before it can be completed. We test the hypothesis that the capacity to maintain the two task sets so as to avoid mutual interference will depend on working memory. We use Baddeley and Hitch’s multicomponent working memory approach to investigate this. Experiment 1 uses articulatory suppression to examine the potential role of subvocal rehearsal, finding no impact on performance. Experiment 2 uses backward counting to impose an additional executive load, finding a major impact on performance even with the simple task of counting back in ones. This took the form of more pervasive effects of stimulus overlap that could be interpreted in terms of a change in the way the two tasks were managed. The differential impacts of the concurrent tasks indicated that multi-tasking is dependent on working memory, where it draws on limited capacity executive resources, but not on the capacity for temporary phonological storage.

Cerebellar contributions to sequence prediction in verbal working memory

Verbal working memory is one of the most studied non-motor functions with robust cerebellar involvement. While the superior cerebellum (lobule VI) has been associated with articulatory control, the inferior cerebellum (lobule VIIIa) has been linked to phonological storage. The present study was aimed to elucidate the differential roles of these regions by investigating whether the cerebellum might contribute to verbal working memory via predictions based on sequence learning/detection. 19 healthy adult subjects completed an fMRI-based Sternberg task which included repeating and novel letter sequences that were phonologically similar or dissimilar. It was hypothesized that learning a repeating sequence of study letters would reduce phonological storage demand and associated right inferior cerebellar activations and that this effect would be modulated by phonological similarity of the study letters. Specifically, while increased phonological storage demand due to high phonological similarity was expected to be reflected in increased right inferior cerebellar activations for similar relative to dissimilar study letters, the reduction in activation for repeating relative to novel sequences was expected to be more profound for phonologically similar than for dissimilar study letters, especially at higher memory load. Results confirmed the typical effects of cognitive load (5 vs. 2 study letters) and phonological similarity in several cerebellar and neocortical brain regions as well as in behavioral data (accuracy and response time). Importantly, activations in superior and inferior cerebellar regions were differentially modulated as a function of similarity and sequence novelty, indicating that particularly lobule VIIIa may contribute to verbal working memory by generating predictions of letter sequences that reduce the likelihood of phonological loop failure before stored items need to be retrieved. The present study is consistent with other investigations that support prediction, which can be based on sequence learning or detection, as an overarching cerebellar function.

Does the structure of working memory in EL children vary across age and two language systems?

ABSTRACTThis study examined the cross-sectional structure of working memory (WM) among elementary school English learners (ELs). A battery of WM tasks was administered in Spanish (L1) and English (L2) within five age groups (ages 6, 7, 8, 9, & 10). Confirmatory factor analysis showed a three-factor structure of WM emerged in both L1 and L2 administrations for each age group. The important findings, however, were: (1) the separation between the executive component and storage component (phonological loop) structure of WM increased as a function of age within both language systems, (2) the structure of WM supported a domain general phonological storage component and a domain general executive system across both language systems, and (3) the visual-spatial WM system shared minimal variance with the executive system. Taken together, the findings support Baddeley’s multicomponent model (e.g., Baddeley & Logie, 1999. The multiple-component model. In A. Miyake & P. Shah (Eds.), Models of working memory: Mechanisms of active maintenance and executive control (pp. 28–61). Cambridge: Cambridge University Press) as a good fit to the structure of WM in EL children’s English and Spanish language system.

Executive dysfunction in patients with spinocerebellar ataxia type 3.

The aim of this study was to assess the cognitive functions of patients with spinocerebellar ataxia type 3(SCA3). We examined 15 patients with genetically confirmed SCA3 and 15 healthy control subjects matched for age, years of education, and intellectual ability. We administered verbal memory (word recall and word recognition) and executive function tasks (word fluency test, forward and backward digit and visual span tests, Kana Pick-out Test, Trail Making Test, and conflicting instructions and a Go/NoGo task from the Frontal Assessment Battery). We found that patients with SCA3 had significantly lower scores than the healthy control subjects on the word recall, semantic, and letter fluency, and backward digit span tests, while word recognition was well preserved. The other executive function tests showed preserved functions in the SCA3 group, indicating that visual working memory, and attention and inhibition control were not affected. The patients with SCA3 showed impaired word recall and intact word recognition, and accordingly, episodic memory encoding and storage processes in short-term memory were preserved. In category and letter-fluency tests, impairment was attributable to word-retrieval from semantic memory. Impaired verbal working memory may be involved in the retrieval of verbal information from phonological storage by means of continuous subvocal rehearsal, rather than a deficit in initial phonological encoding. Essential executive dysfunction in patients with SCA3 may be due to damage in the cerebellar cortex-ventral dentate nucleus-thalamus-prefrontal cortex circuits, which are involved in strategic retrieval of verbal information from different modes of memory storage.

Similarities between the irrelevant sound effect and the suffix effect

Although articulatory suppression abolishes the effect of irrelevant sound (ISE) on serial recall when sequences are presented visually, the effect persists with auditory presentation of list items. Two experiments were designed to test the claim that, when articulation is suppressed, the effect of irrelevant sound on the retention of auditory lists resembles a suffix effect. A suffix is a spoken word that immediately follows the final item in a list. Even though participants are told to ignore it, the suffix impairs serial recall of auditory lists. In Experiment 1, the irrelevant sound consisted of instrumental music. The music generated a significant ISE that was abolished by articulatory suppression. It therefore appears that, when articulation is suppressed, irrelevant sound must contain speech for it to have any effect on recall. This is consistent with what is known about the suffix effect. In Experiment 2, the effect of irrelevant sound under articulatory suppression was greater when the irrelevant sound was spoken by the same voice that presented the list items. This outcome is again consistent with the known characteristics of the suffix effect. It therefore appears that, when rehearsal is suppressed, irrelevant sound disrupts the acoustic-perceptual encoding of auditorily presented list items. There is no evidence that the persistence of the ISE under suppression is a result of interference to the representation of list items in a postcategorical phonological store.

Anatomical Modularity of Verbal Working Memory? Functional Anatomical Evidence from a Famous Patient with Short-Term Memory Deficits

Cognitive skills are the emergent property of distributed neural networks. The distributed nature of these networks does not necessarily imply a lack of specialization of the individual brain structures involved. However, it remains questionable whether discrete aspects of high-level behavior might be the result of localized brain activity of individual nodes within such networks. The phonological loop of working memory, with its simplicity, seems ideally suited for testing this possibility. Central to the development of the phonological loop model has been the description of patients with focal lesions and specific deficits. As much as the detailed description of their behavior has served to refine the phonological loop model, a classical anatomoclinical correlation approach with such cases falls short in telling whether the observed behavior is based on the functions of a neural system resembling that seen in normal subjects challenged with phonological loop tasks or whether different systems have taken over. This is a crucial issue for the cross correlation of normal cognition, normal physiology, and cognitive neuropsychology. Here we describe the functional anatomical patterns of JB, a historical patient originally described by Warrington et al. (1971), a patient with a left temporo-parietal lesion and selective short phonological store deficit. JB was studied with the H215O PET activation technique during a rhyming task, which primarily depends on the rehearsal system of the phonological loop. No residual function was observed in the left temporo-parietal junction, a region previously associated with the phonological buffer of working memory. However, Broca's area, the major counterpart of the rehearsal system, was the major site of activation during the rhyming task. Specific and autonomous activation of Broca's area in the absence of afferent inputs from the other major anatomical component of the phonological loop shows that a certain degree of functional independence or modularity exists in this distributed anatomical-cognitive system.

Role of Left Hemisphere Language Areas in Visuospatial Working Memory

Role of Left Hemisphere Language Areas in Visuospatial Working Memory