Short-term Memory In Individuals Research Articles

Verbal Short-Term Memory Disturbance in the Primary Progressive Aphasias: Challenges and Distinctions in a Clinical Setting.

Impaired verbal ‘phonological’ short-term memory is considered a cardinal feature of the logopenic variant of primary progressive aphasia (lv-PPA) and is assumed to underpin most of the language deficits in this syndrome. Clinically, examination of verbal short-term memory in individuals presenting with PPA is common practice and serves two objectives: (i) to help understand the possible mechanisms underlying the patient’s language profile and (ii) to help differentiate lv-PPA from other PPA variants or from other dementia syndromes. Distinction between lv-PPA and the non-fluent variant of PPA (nfv-PPA), however, can be especially challenging due to overlapping language profiles and comparable psychometric performances on verbal short-term memory tests. Here, we present case vignettes of the three PPA variants (lv-PPA, nfv-PPA, and the semantic variant (sv-PPA)) and typical Alzheimer’s disease (AD). These vignettes provide a detailed description of the short-term and working memory profiles typically found in these patients and highlight how speech output and language comprehension deficits across the PPA variants differentially interfere with verbal memory performance. We demonstrate that a combination of verbal short-term and working memory measures provides crucial information regarding the cognitive mechanisms underlying language disturbances in PPA. In addition, we propose that analogous visuospatial span tasks are essential for the assessment of PPA as they measure memory capacity without language contamination.

Clinician perspectives on the assessment of short-term memory in aphasia

ABSTRACT Background: Verbal short-term memory (STM) and the related ability, working memory (WM), are widely understood to be integral components of language production and comprehension. However, assessment of these abilities in people with aphasia is hampered by a lack of valid, standardized measures that are clinically appropriate. Focusing primarily on verbal STM, we held a series of five focus groups with speech-language pathologists (SLPs) to understand better their current clinical practices and their beliefs and attitudes regarding assessment of verbal STM in aphasia. Aims: The purpose of this study was to explore the attitudes, beliefs and preferences of clinical SLPs to determine: (1) current practices related to verbal STM assessment; (2) the extent to which practices reflect current theories of aphasia and the role of verbal STM in language processing; and (3) practical considerations regarding aphasia assessment in clinical practice. Methods & Procedures: Five focus groups were conducted using a semi-structured interview protocol with a total of 44 SLPs. Grounded theory methodology was used to collect, code and analyse the data. Codes were reviewed to identify emerging themes. Themes were compared to explore meta-themes, connections and potential theoretical frameworks. Outcomes & Results: Five main themes were identified: (1) The theoretical understanding that clinical SLPs have regarding the role of verbal STM in aphasia is not always consistent with clinical practice; (2) Clinical SLPs highly value functionally relevant assessments; (3) The intense time constraints in clinical practice affect all aspects of assessment; (4) Clinical SLPs feel that there is a lack of appropriate tests for assessment of STM in aphasia; and (5) Clinical SLPs prefer tests that are comprehensive, easy to administer and psychometrically sound. Conclusions: Clinical SLPs report a lack of standardized measures to assess STM in individuals with aphasia. Researchers are met with several challenges in the development of these tests including effective communication with clinicians regarding the benefit of verbal STM assessments, especially as it relates to functional skills, and the creation of a test that is comprehensive yet simple, quick and easy to administer.

Citicoline Improves Human Vigilance and Visual Working Memory: The Role of Neuronal Activation and Oxidative Stress.

Introduction:Psychomotor performance task is used to assess the arousal and cognitive functions of the central nervous system. Alternatively, human visual working memory reflects the capability of the individual’s short-term memory. Psycho-mental stimuli are linked to the stimulation of Malondialdehyde (MDA) formations. Citicoline is a nootropic nucleotide agent with a favorable effect on the augmentation of human memory and cognitive function. Thus, the purpose of this study was to determine the effect of citicoline on human vigilance, visual working memory, and oxidative stress using healthy volunteers.Methods:40 healthy volunteers were enrolled and divided into two groups: group A: 20 volunteers received 500mg/day starch capsule for two weeks and group B: 20 volunteers received 500mg/day citicoline capsule for two weeks. Human vigilance, visual working memory, and oxidative stress markers of each volunteer were assessed before and after citicoline and placebo intake. The obtained data were analyzed by SPSS regarding P<0.05 as statistically significant.Results:Placebo had no significant effect on human vigilance and visual working memory after two weeks of therapy (P>0.05), whereas citicoline improved most variables of psychomotor performances and working memory (P<0.01). Placebo significantly increased serum MDA levels from 19.44±2.11 to 29.66±3.28 nmol/mL (P=0.0001), while citicoline significantly decreased MDA serum levels from 19.11±2.66 to 15.63±1.33 nmol/mL (P=0.0001).Conclusion:Citicoline improves human psychomotor vigilance, arousal, and visual working memory with significant amelioration of oxidative stress compared with placebo.

Memory coding in individuals with Down syndrome

Previous research has identified a deficit in phonological short-term memory in individuals with Down syndrome.The present work aimed to analyze how a group of 30 individuals with Down syndrome performed in a picture span task compared with 30 typically developing children of the same mental age. The task involved four conditions (i.e., dissimilar, phonologically similar, visually similar, and long-name items) chosen to analyze the strategy used by individuals with Down syndrome to code visually presented nameable items.Individuals with Down syndrome performed less well than typically developing children. Both groups showed the visual similarity effect.Taken together, our results confirm that individuals with Down syndrome have a verbal working memory deficit, even when nameable items are presented visually. Mental age appears to be an important determinant of memory coding stage in individuals with Down syndrome.

Visuospatial support for verbal short-term memory in individuals with Down syndrome

Individuals with Down syndrome (DS) tend to have impaired verbal short-term memory (STM), which persists even when visual support is provided for carrying out verbal tasks. Objective: The current study aims to investigate whether visuospatial support, rather than just visual, can compensate for verbal STM deficits in these individuals. The performance of 25 children and adolescents with DS (mean age = 12.5, SD = 3.8) on five word span tasks was compared with that of two groups of typically developing children, matched for mental age ( N = 25; mean age = 6.0, SD = .2) and for receptive vocabulary ( N = 25; mean age = 4.0, SD = .8). Four of the five tasks varied in terms of input and output – verbal and/or visual – and the fifth task included a spatial component in addition to visual input and output. DS individuals performed equally bad in the pure verbal task and in those with visual components; however, there was a significant improvement when the spatial component was included in the task. The mental age matched group outperformed DS individuals in all tasks except for that with the spatial component; the receptive vocabulary matched group, outperformed DS individuals only in the pure verbal task. We found that visuospatial support improves verbal STM in individuals with DS. This result may have implications for intervention purposes.

Verbal Short-Term Memory in Individuals With Chromosome 22q11.2 Deletion: Specific Deficit in Serial Order Retention Capacities?

Many researchers have recently explored the cognitive profile of velocardiofacial syndrome (VCFS), a neurodevelopmental disorder linked to a 22q11.2 deletion. However, verbal short-term memory has not yet been systematically investigated. We explored verbal short-term memory abilities in a group of 11 children and adults presenting with VCFS and two control groups, matched on either CA or vocabulary knowledge, by distinguishing short-term memory for serial order and item information. The VCFS group showed impaired performance on the serial order short-term memory tasks compared to both control groups. Relative to the vocabulary-matched control group, item short-term memory was preserved. The implication of serial order short-term memory deficits on other aspects of cognitive development in VCFS (e.g., language development, numerical cognition) is discussed.

Word-length effect in verbal short-term memory in individuals with Down's syndrome.

Many studies have indicated that individuals with Down's syndrome (DS) show a specific deficit in short-term memory for verbal information. The aim of the present study was to investigate the influence of the length of words on verbal short-term memory in individuals with DS. Twenty-eight children with DS and 10 control participants matched for memory span were tested on verbal serial recall and speech rate, which are thought to involve rehearsal and output speed. Although a significant word-length effect was observed in both groups for the recall of a larger number of items with a shorter spoken duration than for those with a longer spoken duration, the number of correct recalls in the group with DS was reduced compared to the control subjects. The results demonstrating poor short-term memory in children with DS were irrelevant to speech rate. In addition, the proportion of repetition-gained errors in serial recall was higher in children with DS than in control subjects. The present findings suggest that poor access to long-term lexical knowledge, rather than overt articulation speed, constrains verbal short-term memory functions in individuals with DS.

Language, cognition, and short-term memory in individuals with Down syndrome.

The developmentally emerging phenotype of language and cognition in individuals with Down syndrome is summarized on the basis of the project's prior work. Identified are a) the emerging divergence of expressive and receptive language, b) the emerging divergence of lexical and syntactic knowledge in each process, and c) the emerging divergence within cognitive skills of auditory short-term memory and visuospatial short-term memory from other visuospatial skills. Expressive syntax and auditory short-term memory are identified as areas of particular difficulty. Evidence for the continued acquisition of language skills in adolescence is presented. The role of the two components of working memory, auditory and visual, in language development is investigated in studies of narrative and longitudinal change in language skills. Predictors of individual differences during six years of language development are evaluated through hierarchical linear modelling. Chronological age, visuospatial short-term memory, and auditory-short term memory are identified as key predictors of performance at study entry, but not individual change over time, for expressive syntax. The same predictors account for variation in comprehension skill at study outset; and change over the six years can be predicted by chronological age and the change in visuospatial short-term memory skills.