Phonological Store Research Articles

Phonological storage and executive function deficits in children with mathematics difficulties

Children with mathematics difficulties suffer from working memory deficits. This study investigated the deficit profile of phonological storage and executive functions in working memory among children with mathematics difficulties. Based on multiple instruments and two assessment points, 68 children were screened out of 805 fifth graders. Of these 68 children, 18 were classified as children with only mathematics difficulties (MD), 20 were classified as children with mathematics and reading difficulties (MDRD), and 30 were typically developing (TD) peers matched on age and general ability. Measures for phonological storage, dual-task performance, inhibition, and updating of verbal and numerical materials were administered individually. Results showed that compared with the TD group, children with MD exhibited storage and inhibition deficits specific to numerical information and dual-task deficits of both verbal and numerical information, whereas children with MDRD showed extensive deficits on phonological storage and executive functions on both verbal and numerical tasks. Moreover, executive function deficits were not confined to phonological storage deficits. Implications of the findings for the working memory deficit profile and working memory training among children with mathematics difficulties were discussed.

Is the frontal dysexecutive syndrome due to a working memory deficit? Evidence from patients with stroke

Although frontal dysexecutive disorders are frequently considered to be due to working memory deficit, this has not been systematically examined and very little evidence is available for impairment of working memory in frontal damage. The objective of this study was to examine the components of working memory, their anatomy and the relations with executive functions in patients with stroke involving the frontal or posterior cortex. The study population consisted of 29 patients (frontal: n=17; posterior: n=12) and 29 matched controls. Phonological loop (letter and word spans, phonological store; rehearsal process), visuospatial sketchpad (visuospatial span) and the central executive (working memory span, dual task and updating process) were examined. The group comparison analysis showed impairment in the frontal group of: (i) verbal spans (P<0.03); (ii) with a deficit of the rehearsal process (P=0.006); (iii) visuospatial span (P=0.04); (iv) working memory span (P=0.001) that disappeared after controlling for verbal span and (v) running memory (P=0.05) unrelated to updating conditions. The clinical anatomical correlation study showed that impairment of the central executive depended on frontal and posterior lesion. Cognitive dysexecutive disorders were observed in 11/20 patients with central executive deficit and an inverse dissociation was observed in two patients. Receiver operating characteristic curve analysis indicated that cognitive dysexecutive disorders had the highest ability to discriminate frontal lesions (area under curve=0.844, 95% confidence interval: 0.74-0.95; P=0.0001; central executive impairment: area under curve=0.732, 95% confidence interval: 0.57-0.82; P=0.006). This study reveals that frontal lesions induce mild impairment of short-term memory associated with a deficit of the rehearsal process supporting the role of the frontal lobe in this process; the central executive depends on lesions in the frontal lobe and posterior regions accounting for its low frequency and the negative results of group studies. Finally, the frontal dysexecutive syndrome cannot be attributed to central executive impairment, although it may contribute to some dysexecutive disorders.

Functional deficits in phonological working memory in children with intellectual disabilities

Recent studies indicate that children with intellectual disabilities have functional limitations primarily in the phonological loop of working memory (Baddeley, 1986). These findings are indicative of a specific structural deficit. Building on this research, the present study examines whether it is possible to identify specific phonological subfunctions as causal factors in these qualitative deviations from typical development found in children with intellectual disabilities. In a three-group design, specific subfunctions of phonological working memory were examined in students of the same mental age (one group of 15-year-olds with mild intellectual disability [IQ 50-69], one group of 10-year-olds with borderline intellectual disability [IQ 70-84], and one group of 7-year-olds of average intelligence [IQ 85-115]). The automatic activation of the subvocal rehearsal process was operationalized by the word-length effect; the size of the phonological store, by a task involving repetition of nonwords of differing syllable length; and accuracy of processing, by both the phonological similarity effect and the quality of acoustic presentation of the nonword repetition task (distorted vs. undistorted item presentation). The results revealed impairment of the phonological store only in terms of reduced storage capacity, and showed that this deficit increased with length of the item sequences to be remembered. However, this deficit was observed only in children with mild intellectual disability; the performance of children with borderline intellectual disability corresponded with that of a control group of 7-year-olds matched for mental age. The findings are discussed in the context of the two-component model of the phonological loop. They indicate that deficits in storage capacity are associated with deficits in language development and thus seem to be one of the causes of cognitive impairment in individuals with mild intellectual disability.

Is there brief temporal buffering of successive visual inputs?

The part-report advantage has been used to identify short-lived forms of visual storage (Sperling, 1960). We adopt the part-report paradigm to test whether visual memory can preserve, for a brief time, successive inputs and their temporal order. In our experiments, two successive arrays, each of 4 digits, were presented on each trial. The two arrays were spatially coincident, and each was followed by a random pattern-mask. In the part-report conditions, an auditory cue indicated whether the participant should report the first array or the second array. The results consistently showed a part-report advantage, which ranged in size from 16% to 37%. Delaying the cue by 500ms abolished most of this advantage, in that performance was then similar to that in whole-report conditions. Subsequent experiments confirmed that the part-report superiority we measure is not achieved by (a) making eye movements that spatially displace the second array relative to the first; (b) extracting information from a single snapshot containing an integrated representation of the targets and masks; or (c) transferring a subset of material to a phonological store. We propose instead that observers have access to a limited, rapidly decaying representation of successive visual inputs stored in temporal sequence.

Neural Correlates of Sublexical Processing in Phonological Working Memory

This study investigated links between working memory and speech processing systems. We used delayed pseudoword repetition in fMRI to investigate the neural correlates of sublexical structure in phonological working memory (pWM). We orthogonally varied the number of syllables and consonant clusters in auditory pseudowords and measured the neural responses to these manipulations under conditions of covert rehearsal (Experiment 1). A left-dominant network of temporal and motor cortex showed increased activity for longer items, with motor cortex only showing greater activity concomitant with adding consonant clusters. An individual-differences analysis revealed a significant positive relationship between activity in the angular gyrus and the hippocampus, and accuracy on pseudoword repetition. As models of pWM stipulate that its neural correlates should be activated during both perception and production/rehearsal [Buchsbaum, B. R., & D'Esposito, M. The search for the phonological store: From loop to convolution. Journal of Cognitive Neuroscience, 20, 762-778, 2008; Jacquemot, C., & Scott, S. K. What is the relationship between phonological short-term memory and speech processing? Trends in Cognitive Sciences, 10, 480-486, 2006; Baddeley, A. D., & Hitch, G. Working memory. In G. H. Bower (Ed.), The psychology of learning and motivation: Advances in research and theory (Vol. 8, pp. 47-89). New York: Academic Press, 1974], we further assessed the effects of the two factors in a separate passive listening experiment (Experiment 2). In this experiment, the effect of the number of syllables was concentrated in posterior-medial regions of the supratemporal plane bilaterally, although there was no evidence of a significant response to added clusters. Taken together, the results identify the planum temporale as a key region in pWM; within this region, representations are likely to take the form of auditory or audiomotor "templates" or "chunks" at the level of the syllable [Papoutsi, M., de Zwart, J. A., Jansma, J. M., Pickering, M. J., Bednar, J. A., & Horwitz, B. From phonemes to articulatory codes: an fMRI study of the role of Broca's area in speech production. Cerebral Cortex, 19, 2156-2165, 2009; Warren, J. E., Wise, R. J. S., & Warren, J. D. Sounds do-able: auditory-motor transformations and the posterior temporal plane. Trends in Neurosciences, 28, 636-643, 2005; Griffiths, T. D., & Warren, J. D. The planum temporale as a computational hub. Trends in Neurosciences, 25, 348-353, 2002], whereas more lateral structures on the STG may deal with phonetic analysis of the auditory input [Hickok, G. The functional neuroanatomy of language. Physics of Life Reviews, 6, 121-143, 2009].

Cross‐Linguistic Differences in Digit Memory Span

This study investigated whether the better performance of the Chinese in digit memory span tasks was due only to the shorter pronunciation duration of Chinese digit names, or to enhanced visuospatial sketchpad abilities, or to both. Results of the experiment showed that the Chinese outperformed their Malay counterparts in digit memory span tasks because Chinese digit names had shorter pronunciation durations than Malay digit names and not because the Chinese had better visuospatial sketchpad abilities than the Malays. The results thus support Baddeley's phonological loop hypothesis as an account for cross‐linguistic differences in digit memory spans. Because memory traces are subject to decay and the phonological store is temporally limited, the shorter the pronunciation duration of digit names in a language, the more digits one can rehearse within a limited time period, and therefore the larger is one's short‐term digit span in that language.

Information and Spirit

Definitions that relate to each other are derived for Information and spirit. An experiment that seeks to stimu- late the phonological store is described and the responses obtained analyzed, using a unique monitoring method based on variations in electrical permittivity when neurons fire. The importance of the non-sensory inputs to the sub-vocal rehearsal system in the phonological lop is mentioned. An experiment is outlined wherein a mental stimulus is applied to the sub- ject and the electrical response is monitored and converted to audible speech. This is thus non-vocal speech and its charac- teristics are examined in relation to the original stimuli. The results revealed openings for further research.

Are multiplication facts stored only in the phonological format?

Event Abstract Back to Event Are multiplication facts stored only in the phonological format? Marta Sobanska1* 1 University of Finance and Management, Poland According to the triple-code model (Dehaene&Cohen, 1995), multiplication problems and its results are stored in the long term memory as the phonological sequences of words, eg. "three times four, twelve". The aim of the present studies is to verify the phonological storage hypothesis, which postulates that the phonological representation of numbers is the only kind of arithmetical facts of representation. Study 1: A case study of a patient MF, a 76-year-old chemistry teacher after a left hemisphere infarction. MF suffered from a mixed aphasia with moderate speaking and mild comprehension impairments. Eighty one problems (from 1x1 to 9x9) were presented to MF on two sheets of paper. Her task consisted on reading them aloud and giving the result in two ways: written and orally. Although she made 35 reading errors (43%), she gave the correct answers to 77 of 81 problems (95%) in the written modality, and to 70 of 81 problems (86%) in the spoken one. Study 2: A total of 12 healthy right-handed people (6 men, average age = 52) were tested. Each subject performed 81 multiplication problems (from 1x1 to 9x9), and 36 subtraction problems (from 2-1 to 9-8) four times, in blocks which differed in format of stimuli presentation and response (Arabic digits or spoken number words). The influence of the presentation/response format on the reaction time of multiplication and "small" multiplication (problems which resulted were not larger than 25) was different: in the case of "small" multiplication, the response latencies were similar to those of subtraction. The findings are discussed in the context of the triple-code model and other theories concerning the representations underlying arithmetic problem solving. Keywords: Neural Bases, Problem Solving Conference: XI International Conference on Cognitive Neuroscience (ICON XI), Palma, Mallorca, Spain, 25 Sep - 29 Sep, 2011. Presentation Type: Poster Presentation Topic: Poster Sessions: Neural Bases of Arithmetics and Numerosity Citation: Sobanska M (2011). Are multiplication facts stored only in the phonological format?. Conference Abstract: XI International Conference on Cognitive Neuroscience (ICON XI). doi: 10.3389/conf.fnhum.2011.207.00103 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 16 Nov 2011; Published Online: 25 Nov 2011. * Correspondence: Dr. Marta Sobanska, University of Finance and Management, Warsaw, Poland, marta_sobanska@yahoo.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Marta Sobanska Google Marta Sobanska Google Scholar Marta Sobanska PubMed Marta Sobanska Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Cognitive Functions of the Cerebellum

The cerebellum, the often forgotten “little brain” at the back the cerebrum, has gained significant attention in the last two decades (Desmond, 2010). Although traditionally considered limited in function to component processes of motor control, astute clinicians and researchers posited that such a highly organized brain structure composed of approximately as many neurons as in the cerebrum must have some cognitive function or at least exert some influence on cognitive processes. Despite carefully conducted studies yielding convincing data, papers imputing cognitive function to the cerebellum had been banished to the carousel of rejection. As noted in the paper by Henrietta Leiner, “One peer reviewer actually wrote, ‘This couldn’t possibly be true or we would have discovered it long ago.’” Even current neurology handbooks tend to limit discussion on the outcome of cerebellar pathology to specific motor signs and symptoms. A change in the course of tradition has required a strong theoretical basis, creative neuroanatomy, perceptive clinical observation, rigorous neuropsychological testing, all complemented by human brain imaging. Forward-thinking scientists in each of these areas contributed to this special issue of Neuropsychology Review on cognitive functions of the cerebellum. The five papers are written from different perspectives on the cerebellum, its far-reaching yet systematic connections with supratentorial brain structures, its functions, and the challenges faced in presenting discoveries inconsistent with traditional beliefs. Henrietta Leiner, a mathematician, physicist, computer scientist turned neuroscientist, pioneered new horizons in all areas into which she delved. New voices from dogged thinkers formed a critical impetus for rigorous study to challenge cerebellar doctrine about its functions and also its evolutionary purpose. As noted in the current piece, the Leiners (Henrietta and her late husband, Alan) had put forth the proposition that enlargement of the cerebellum in humans, complemented with development of the massive connections with the supratentorium, occurred in step with the emergence of language. Thus, the cerebellum may have enabled rapid language-based thinking and working memory abilities to support speech perception and production. Jeremy Schmahmann relates his scientific pursuit of cerebellar function through anatomy, neurology, and neuropsychology. His story echoes those of other innovators of new concepts about cerebellar functions, indicating resistance from peers in their ability to break set from the indoctrination of the position that the functions of the cerebellum are solely in the motor domain and cannot contribute to higher-order cognition. Dr. Schmahmann’s systematic analysis of the cerebellum’s functions has led him to delineate a set of general principles of its functions. Included is what he has identified as the Cerebellar Cognitive Affective Syndrome, which has been a cornerstone for current theories about autism and other neurological disorders with an affective component. Andreea Bostan and Peter Strick present an anatomically-based argument that structural interactions between cerebellar and supratentorial structures, including the basal ganglia, provide the communication means for the cerebellum to influence higher-order functions. They review their exquisite tracing studies using rabies virus, which enables identification of multi-synaptic connections traversing extensively across brain systems. The success of these studies has been pivotal in providing incontrovertible evidence for a complex system of closed loop bidirectional communication between selective cerebellar and cortical sites and between selective cerebellar and basal ganglial sites in primates. Cherie Marvel and John Desmond provide replicable support from functional imaging studies on the role of selective regions of the cerebellum in verbal working memory performance in humans. Given the role of the cerebellum as contributing to phonological storage (possibly unique to spoken language) and perhaps even extending working memory capacity, these studies are in keeping with the proposition of the Leiners that the cerebellum, with its great size and high-speed connectivity, with selective regions of the supratentorial brain was essential for human language to evolve. Natalie Zahr, Anne-Lise Pitel, Sandra Chanraud, and I present a focused review on how human neuroimaging studies of chronic alcoholism have furthered our understanding of cerebellar function. The review includes studies using a variety of magnetic resonance imaging (MRI) methods, including structural MRI, diffusion tensor imaging (DTI), fMRI, and MR spectroscopy in conjunction with neuropsychological study. The central tenet is that disruption of an executive frontocerebellar network is a major contributor to characteristic behaviors of alcoholics that, on the one hand, sustain alcohol use disorders possibly through cerebellar conditioning mechanisms, and on the other hand, lead to compensation for frontally-based dysfunctions in alcoholism. As imaging methods improve, we may be in the position to visualize and quantify the integrity of structures in vivo currently hidden within the cerebellum, such as the dentate nucleus (cover figure), in addition to assessing their associated functions. Figure 1 Cover image

Functional topography of the cerebellum in verbal working memory.

Speech-both overt and covert-facilitates working memory by creating and refreshing motor memory traces, allowing new information to be received and processed. Neuroimaging studies suggest a functional topography within the sub-regions of the cerebellum that subserve verbal working memory. Medial regions of the anterior cerebellum support overt speech, consistent with other forms of motor execution such as finger tapping, whereas lateral portions of the superior cerebellum support speech planning and preparation (e.g., covert speech). The inferior cerebellum is active when information is maintained across a delay, but activation appears to be independent of speech, lateralized by modality of stimulus presentation, and possibly related to phonological storage processes. Motor (dorsal) and cognitive (ventral) channels of cerebellar output nuclei can be distinguished in working memory. Clinical investigations suggest that hyper-activity of cerebellum and disrupted control of inner speech may contribute to certain psychiatric symptoms.

The Role of Working Memory in the Language-Learning Process of Children with Cochlear Implants

In some cases, language acquisition of children with a cochlear implant is observed as being suboptimal. Recent models of cognitive psychology assume that a crucial factor involved may be a functional impairment of the working memory. The best-known model of working memory is that by Baddeley et al. (1998). It incorporates two modality-specific subsystems for phonological and visual information processing as well as what is called an episodic buffer for information processing that transcends different modalities, all controlled by the central executive, which chiefly serves to facilitate attention control. We were interested in only one of these subsystems — the phonological loop, as this is most important for hearing. The idea is that speech input enters the phonological store where it is retained for around two seconds for analysis and processing before it is then, as a phonological representation of the new word, converted into a ‘new entry’, so to speak, that is registered in the memory. Where auditory input occurs over a lengthier period of time, the analysis of its phonological characteristics may be extended by a process of internal speech and repetition, thus also resulting in processing and retention. This mechanism is also referred to as subvocal rehearsal. There is a new explanatory approach that departs from what are termed ‘demographic factors’ and seeks causes in non-sensory aspects, i.e. not in ‘hearing earlier’, ‘hearing better’, or ‘hearing for longer’, but in the processing — and processing quality — of linguistic input by the child as they learn language.

Analysis of naming errors during cortical stimulation mapping: Implications for models of language representation

This study reports on the characteristics and distribution of naming errors of patients undergoing cortical stimulation mapping (CSM). During the procedure, electrical stimulation is used to induce temporary functional lesions and locate ‘essential’ language areas for preservation. Under stimulation, patients are shown slides of common objects and asked to name them. Cortical stimulation can lead to a variety of naming errors. In the present study, we aggregate errors across patients to examine the neuroanatomical correlates and linguistic characteristics of six common errors: semantic paraphasias, circumlocutions, phonological paraphasias, neologisms, performance errors, and no-response errors. Aiding analysis, we relied on a suite of web-based querying and imaging tools that enabled the summative mapping of normalized stimulation sites. Errors were visualized and analyzed by type and location. We provide descriptive statistics to characterize the commonality of errors across patients and location. The errors observed suggest a widely distributed and heterogeneous cortical network that gives rise to differential patterning of paraphasic errors. Data are discussed in relation to emerging models of language representation that honor distinctions between frontal, parietal, and posterior temporal dorsal implementation systems and ventral-temporal lexical semantic and phonological storage and assembly regions; the latter of which may participate both in language comprehension and production.

Working memory functions in children with different degrees of intellectual disability

In recent years, there has been increased research interest in the functioning of working memory in people with intellectual disabilities. Although studies have repeatedly found these individuals to have weak working memory skills, few investigations have distinguished between different degrees of intellectual disability. This study aims to help close this research gap and, in so doing, to examine whether the deficits observed reflect a developmental lag or a qualitative deviation from normal development. In a 5-group design, the working memory performance of a group of 15-year-olds with mild intellectual disability (IQ 50-69) was compared with that of two groups of children (aged 10 and 15 years) with borderline intellectual disability (IQ 70-84) and with that of two groups of children with average intellectual abilities (IQ 90-115) matched for mental and chronological age (aged 7 and 15 years). All children were administered a comprehensive battery of tests assessing the central executive, the visual-spatial sketchpad, and the phonological loop. The results showed deficits in all three components of working memory, and revealed that these deficits increased with the degree of intellectual disability. The findings indicate that, relative to their mental age peers, children with learning difficulties show structural abnormalities in the phonological store of the phonological loop, but developmental lags in the other two subsystems. Similar patterns of results emerged for both subgroups of children with intellectual disability, indicating that problems with phonological information processing seem to be one of the causes of cognitive impairment in individuals with intellectual disability.

Does Greater Phonological Storage Capacity Correlate with Levels of Intentionality and Theory of Mind?

Greater phonological storage capacity may be associated with levels of intentionality, and therefore by assumption, Theory of Mind. The participants were 34 high school students in the Midwest (15 girls, 19 boys; age range= 15 to 17 years). The measures were digits forward and digits backward from the Digit Span subtest of the Wechsler Adult Intelligence Scale-III and a measure purporting to assess Theory of Mind and Levels of Intentionality (Kinderman, Dunbar, & Bentall, 1998). There was found to be a weak nonsignificant correlation between digits forward and Levels of Intentionality, and a moderate and significant correlation between digits backward and Levels of Intentionality. The latter correlation was significantly larger. The digits backward test requires not only greater phonological storage capacity but also appears to tap working memory resources. Findings suggest that greater phonological storage capacity is associated with higher intentionality, and by implication, perhaps more elaborate Theory of Mind, but only when the phonological task requires working memory functions.

There are Multiple Contributors to the Verbal Short-Term Memory Deficit in Children with Developmental Reading Disabilities

Prior research has put forth at least four possible contributors to the verbal short-term memory (VSTM) deficit in children with developmental reading disabilities (RD): poor phonological awareness that affects phonological coding into VSTM, a less effective phonological store, slow articulation rate, and fewer/poorer quality long-term memory (LTM) representations. This project is among the first to test the four suppositions in one study. Participants included 18 children with RD and 18 controls. VSTM was assessed using Baddeley's model of the phonological loop. Findings suggest all four suppositions are correct, depending upon the type of material utilized. Children with RD performed comparably to controls in VSTM for common words but worse for less frequent words and nonwords. Furthermore, only articulation rate predicted VSTM for common words, whereas Verbal IQ and articulation rate predicted VSTM for less frequent words, and phonological awareness and articulation rate predicted VSTM for nonwords. Overall, findings suggest that the mechanism(s) used to code and store items by their meaning is intact in RD, and the deficit in VSTM for less frequent words may be a result of fewer/poorer quality LTM representations for these words. In contrast, phonological awareness and the phonological store are impaired, affecting VSTM for items that are coded phonetically. Slow articulation rate likely affects VSTM for most material when present. When assessing reading performance, VSTM predicted decoding skill but not word identification after controlling Verbal IQ and phonological awareness. Thus, VSTM likely contributes to reading ability when words are novel and must be decoded.

Mismatch Response to Polysyllabic Nonwords: A Neurophysiological Signature of Language Learning Capacity

BackgroundThe ability to repeat polysyllabic nonwords such as “blonterstaping” has frequently been shown to correlate with language learning ability but it is not clear why such a correlation should exist. Three alternative explanations have been offered, stated in terms of differences in: (a) perceptual ability; (b) efficiency of phonological loop functioning; (c) pre-existing vocabulary knowledge and/or articulatory skills. In the present study, we used event-related potentials to assess the contributions from these three factors to explaining individual variation in nonword repetition ability.Methodology/Principal Findings59 adults who were subdivided according to whether they were good or poor nonword-repeaters participated. Electrophysiologically measured mismatch responses were recorded to changes in consonants as participants passively listened to a repeating four syllable CV-string. The consonant change could occur in one of four positions along the CV-string and we predicted that: (a) if nonword repetition depended purely on auditory discrimination ability, then reduced mismatch responses to all four consonant changes would be observed in the poor nonword-repeaters, (b) if it depended on encoding or decay of information in a capacity-limited phonological store, then a position specific decrease in mismatch response would be observed, (c) if neither cognitive capacity was involved, then the two groups of participants would provide equivalent mismatch responses. Consistent with our second hypothesis, a position specific difference located on the third syllable was observed in the late discriminative negativity (LDN) window (230–630 ms post-syllable onset).Conclusions/SignificanceOur data thus confirm that people who are poorer at nonword repetition are less efficient in early processing of polysyllabic speech materials, but this impairment is not attributable to deficits in low level auditory discrimination. We conclude by discussing the significance of the observed relationship between LDN amplitude and nonword repetition ability and describe how this relatively little understood ERP component provides a biological window onto processes required for successful language learning.

Working memory deficits in personality disorder traits: A preliminary investigation in a nonclinical sample

The purpose of the present study was to explore cognitive symptoms of personality disorder traits by means of Baddeley’s working memory model. Forty-nine college students were tested for personality disorder traits with the Coolidge Axis II Inventory, and they were given measures assessing executive control, working memory, including general working memory capacity (Operation-Word Span), phonological storage capacity (digits forwards and digits backwards), and three other Wechsler Adult Intelligence Scale subtests. The results indicated that the 14 personality disorder scales had strong positive correlations with a measure of executive function deficits. Among measures of working memory capacity, the Digits Backwards subtest appeared to be the strongest predictor (negatively) of personality disorders according to multiple regressions. It was concluded that personality disorders may express themselves in cognitive ways that are reflected in measures of executive control, working memory capacity, and phonological storage capacity. Directions for further research are offered.

Dyslexic Children Show Short-Term Memory Deficits in Phonological Storage and Serial Rehearsal: An fMRI Study

Dyslexia is primarily associated with a phonological processing deficit. However, the clinical manifestation also includes a reduced verbal working memory (WM) span. It is unclear whether this WM impairment is caused by the phonological deficit or a distinct WM deficit. The main aim of this study was to investigate neuronal activation related to phonological storage and rehearsal of serial order in WM in a sample of 13-year-old dyslexic children compared with age-matched nondyslexic children. A sequential verbal WM task with two tasks was used. In the Letter Probe task, the probe consisted of a single letter and the judgment was for the presence or absence of that letter in the prior sequence of six letters. In the Sequence Probe (SP) task, the probe consisted of all six letters and the judgment was for a match of their serial order with the temporal order in the prior sequence. Group analyses as well as single-subject analysis were performed with the statistical parametric mapping software SPM2. In the Letter Probe task, the dyslexic readers showed reduced activation in the left precentral gyrus (BA6) compared to control group. In the Sequence Probe task, the dyslexic readers showed reduced activation in the prefrontal cortex and the superior parietal cortex (BA7) compared to the control subjects. Our findings suggest that a verbal WM impairment in dyslexia involves an extended neural network including the prefrontal cortex and the superior parietal cortex. Reduced activation in the left BA6 in both the Letter Probe and Sequence Probe tasks may be caused by a deficit in phonological processing. However, reduced bilateral activation in the BA7 in the Sequence Probe task only could indicate a distinct working memory deficit in dyslexia associated with temporal order processing.

The deployment of attention in short-term memory tasks: Trade-offs between immediate and delayed deployment

Memory at times depends on attention, as when attention is used to encode incoming, serial verbal information. When encoding and rehearsal are difficult or when attention is divided during list presentation, more attention is needed in the time following the presentation and just preceding the response. Across 12 experimental conditions observed in several experiments, we demonstrated this by introducing a nonverbal task with three levels of effort (no task, a natural nonverbal task, or an unnatural version of the task) during a brief retention interval in a short-term digit recall task. Interference from the task during the retention interval was greater when resources were drawn away from the encoding of the stimuli by other factors, including unpredictability of the end point of the list, rapid presentation, and a secondary task during list presentation. When those conditions complicate encoding of the list, we argue, attention is needed after the list so that the contents of passive memory (i.e., postcategorical phonological storage and/or precategorical sensory memory) may be retrieved and become the focus of attention for recall.

The Search for the Phonological Store: From Loop to Convolution

The phonological loop system of Baddeley and colleagues' Working Memory model is a major accomplishment of the modern era of cognitive psychology. It was one of the first information processing models to make an explicit attempt to accommodate both traditional behavioral data and the results of neuropsychological case studies in an integrated theoretical framework. In the early and middle 1990s, the purview of the phonological loop was expanded to include the emerging field of functional brain imaging. The modular and componential structure of the phonological loop seemed to disclose a structure that might well be transcribed, intact, onto the convolutions of the brain. It was the phonological store component, however, with its simple and modular quality, that most appealed to the neuroimaging field as the psychological "box" that might most plausibly be located in the brain. Functional neuroimaging studies initially designated regions in the parietal cortex as constituting the "neural correlate" of the phonological store, whereas later studies pointed to regions in the posterior temporal cortex. In this review, however, we argue the phonological store as a theoretical construct does not precisely correspond to a single, functionally discrete, brain region. Rather, converging evidence from neurology, cognitive psychology, and functional neuroimaging argue for a reconceptualization of phonological short-term memory as emerging from the integrated action of the neural processes that underlie the perception and production of speech.