Cerebellar damage produces selective deficits in verbal working memory

Many aspects of human performance require producing sequences of items in serial order. The current study takes a multiple-case approach to investigate whether the system responsible for serial order is shared across cognitive domains, focusing on working memory (WM) and word production. Serial order performance in three individuals with post-stroke language and verbal WM disorders (hereafter persons with aphasia, PWAs) were assessed using recognition and recall tasks for verbal and visuospatial WM, as well as error analyses in spoken and written production tasks to assess whether there was a tendency to produce the correct phonemes/letters in the wrong order. One PWA exhibited domain-specific serial order deficits in verbal and visuospatial WM. The PWA with verbal serial order WM deficit made more serial order errors than expected by chance in both repetition and writing-to-dictation tasks, whereas the other two PWAs showed no serial order deficits in verbal WM and production tasks. These findings suggest separable serial order systems for verbal and visuospatial WM and a shared system for serial order processing in verbal WM and word production. Implications for the domain-generality of WM, its connection to language production, and serial order processing across cognitive functionssc are discussed.

Verbal working memory is poorer for children with hearing loss than for peers with normal hearing (NH), even with cochlear implantation and early intervention. Poor verbal working memory can affect academic performance, especially in higher grades, making this deficit a significant problem. This study examined the stability of verbal working memory across middle childhood, tested working memory in adolescents with NH or cochlear implants (CIs), explored whether signal enhancement can improve verbal working memory, and tested two hypotheses proposed to explain the poor verbal working memory of children with hearing loss: (a) Diminished auditory experience directly affects executive functions, including working memory; (b) degraded auditory inputs inhibit children's abilities to recover the phonological structure needed for encoding verbal material into storage. Fourteen-year-olds served as subjects: 55 with NH; 52 with CIs. Immediate serial recall tasks were used to assess working memory. Stimuli consisted of nonverbal, spatial stimuli and four kinds of verbal, acoustic stimuli: nonrhyming and rhyming words, and nonrhyming words with two kinds of signal enhancement: audiovisual and indexical. Analyses examined (a) stability of verbal working memory across middle childhood, (b) differences in verbal and nonverbal working memory, (c) effects of signal enhancement on recall, (d) phonological processing abilities, and (e) source of the diminished verbal working memory in adolescents with cochlear implants. Verbal working memory remained stable across middle childhood. Adolescents across groups performed similarly for nonverbal stimuli, but those with CIs displayed poorer recall accuracy for verbal stimuli; signal enhancement did not improve recall. Poor phonological sensitivity largely accounted for the group effect. The central executive for working memory is not affected by hearing loss or cochlear implantation. Instead, the phonological deficit faced by adolescents with CIs denigrates the representation in storage and augmenting the signal does not help.

The role of verbal and visuospatial working memory in rule-based and information-integration category learning was examined. Previously, Maddox, Ashby, Ing, and Pickering found that a sequentially presented verbal working memory task did not affect information-integration learning, but disrupted rule-based learning when the rule was on the spatial frequency of a Gabor stimulus. This pattern was replicated in Experiment 1, in which the same category structures were used, but in which the verbal working memory task was replaced with a visuospatial analog. Experiment 2A examined rule-based learning on an oblique orientation and also found both verbal and visuospatial working memory tasks disrupting learning. Experiment 2B examined rule-based learning on a cardinal orientation and found a minimal effect of the verbal working memory task, but a large effect of the visuospatial working memory task. The conceptual significance of cardinal orientations and the role of visuospatial and verbal working memory in category learning are discussed.

Verbal working memory impairments are considered to be core deficits and potential endophenotypic markers in schizophrenia but also in other psychiatric disorders, e.g. in bipolar affective disorder and in attention-deficit/hyperactivity disorder. However, recent experimental neuropsychological studies revealed a remarkable heterogeneity within diagnostic groups regarding the presence or absence of verbal working memory deficits. In the present study, we used optimized voxel-based morphometry in order to investigate gray matter volume differences between two groups of patients with mixed diagnoses (i.e. schizophrenic, bipolar and OCD patients) that only differed from each other with regard to their verbal working memory performance. Those patients with preserved verbal working memory showed a significantly greater gray matter volume in Broca's area, a key structure for verbal working memory function, both when compared to patients with verbal working memory deficit, and when compared to healthy controls (without deficit). Among other possible interpretations, these data could provide first evidence that, in a subgroup of patients, neuroplastic changes in brain areas underlying specific working memory functions may compensate for possible disturbances of these functions due to pathophysiological processes.

Auditory warnings have been shown to interfere with verbal working memory. However, the impact of different types of auditory warnings on working memory tasks must be further researched. This study investigated how different kinds of auditory warnings interfered with verbal and spatial working memory. Experiment 1 tested the potential interference of auditory warnings with verbal working memory. Experiment 2 tested the potential interference of auditory warnings with spatial working memory. Both experiments used a 3 × 3 mixed design: auditory warning type (auditory icons, earcons, or spearcons) was between groups, and task condition (no-warning, identify-warning, or ignore-warning) was within groups. In Experiment 1, earcons and spearcons but not auditory icons worsened the performance on the verbal serial recall task in the identify-warning condition, compared with that in the no-warning or ignore-warning conditions. In Experiment 2, only identifying earcons worsened the performance on the location recall task compared with performance without auditory warnings or when auditory warnings were ignored. Results are discussed from the perspective of working memory resource interference, and their practical application in the selection and design of auditory warning signals is involved.

Event Abstract Back to Event A Common Serial Order Mechanism for Verbal Working Memory and Language Production: Evidence from Aphasia Yingxue Tian1*, Heather R. Dial2, Randi Martin1 and Simon Fischer-Baum1 1 Rice University, United States 2 University of Texas at Austin, United States Serial order information is critical in our daily life, from recalling a phone number, or producing phonemes when saying a word, or writing letters when spelling. In the domain of working memory (WM), there is clear evidence for a dissociation of item-identity and serial-order WM (Majerus, 2018). The current study tests two hypotheses about verbal serial order working memory (SOWM). First, that there is a single SOWM capacity that is involved in both verbal and nonverbal WM. Second, that there is a common order processing capacity shared between verbal WM and language production. Both hypotheses are addressed in a multiple-case study approach, looking at patterns of associations and dissociations in serial order performance in patients with memory and language impairments following stroke. Three chronic aphasic patients (M.B., E.V., and S.H.) were identified with impaired forward and backward digit span (span < 4). They were then tested on verbal WM, including item probe (IP), order probe (OP), and serial reconstruction (SRC). Evidence of SOWM impairments includes poor performance on SRC and impaired OP relative to IP (henceforth referred to as adjusted order span). Patient M.B. exhibited impaired verbal SOWM with both digits (SRC = 3.08) and letters (SRC = 2.45, p’s < .05) as well as with the probe tasks (verbal adjusted order span = 50%, p = .03) when compared to ten age- and education-matched control subjects, whereas the other two patients showed no evidence of a verbal SOWM impairment. To test the single SOWM hypothesis, patients were given the same WM battery with nonverbal materials (visuospatial locations). None of the patients showed nonverbal SOWM impairments. Most critically, M.B. exhibited SOWM deficit in the verbal domain but not the nonverbal domain (SRC = 5.33, nonverbal adjusted order span = 59%, p’s > .05). This dissociation between verbal and nonverbal SOWM systems provides clear evidence against the single SOWM hypothesis. To test the hypothesis that verbal SOWM and language production share a common order processing capacity, we next analyzed phoneme/grapheme errors in a corpus of repetition and spelling tasks. Errors in these tasks were categorized into item, order, and omission errors. M.B. produced significantly more phoneme and grapheme order errors than would be expected by chance (p’s < .001 in Monte Carlo simulation), whereas the other two patients did not have a tendency to make order errors in these tasks. The association between M.B.’s order impairment in verbal WM, spoken production and spelling, along with the fact that E.V. and S.H. do not show order impairments in any of those domains, suggests a common serial order mechanism. In sum, our multiple-case study suggests a common mechanism for serial order between verbal WM and the language production system that is distinct from the serial order mechanism used in nonverbal WM. References Majerus, S. (2018). Verbal working memory and the phonological buffer: The question of serial order. Cortex. Keywords: cognitive neuropsychology, Multiple-case, Language production, working memory, serial order Conference: Academy of Aphasia 57th Annual Meeting, Macau, Macao, SAR China, 27 Oct - 29 Oct, 2019. Presentation Type: Poster presentation Topic: Eligible for student award Citation: Tian Y, Dial HR, Martin R and Fischer-Baum S (2019). A Common Serial Order Mechanism for Verbal Working Memory and Language Production: Evidence from Aphasia. Front. Hum. Neurosci. Conference Abstract: Academy of Aphasia 57th Annual Meeting. doi: 10.3389/conf.fnhum.2019.01.00113 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: 06 May 2019; Published Online: 09 Oct 2019. * Correspondence: Mx. Yingxue Tian, Rice University, Houston, United States, yingxue.tian@rice.edu 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 Yingxue Tian Heather R Dial Randi Martin Simon Fischer-Baum Google Yingxue Tian Heather R Dial Randi Martin Simon Fischer-Baum Google Scholar Yingxue Tian Heather R Dial Randi Martin Simon Fischer-Baum PubMed Yingxue Tian Heather R Dial Randi Martin Simon Fischer-Baum 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.

The present study investigated verbal and spatial working memory (WM) functioning in individuals with the neuro-developmental disorder Williams syndrome (WS) using WM component tasks. While there is strong evidence of WM impairments in WS, previous research has focused on short-term memory and has neglected assessment of executive components of WM. There is a particular lack of consensus concerning the profile of verbal WM functioning in WS. Here, WS participants were compared to typically developing participants matched for (1) verbal ability and (2) spatial ability ( N = 14 in each of the 3 groups). Individuals with WS were impaired on verbal WM tasks, both those involving short-term maintenance of information and executive manipulation, in comparison to verbal-matched controls. Surprisingly, individuals with WS were not impaired on a spatial task assessing short-term maintenance of information in memory (remembering spatial locations) compared to spatial-matched controls. They were, however, impaired on a spatial executive WM task requiring the manipulation of spatial information in memory. The present study suggests that individuals with WS show WM impairments that extend to both verbal and spatial domains, although spatial deficits are selective to executive aspects of WM function.

Verbal working memory and executive deficits have been observed in ecstasy users. The present study sought to establish whether these also extended to visuo-spatial working memory. Thirty-six current ecstasy users, 12 former users (abstinent for at least 6 months) and 31 individuals that had never used ecstasy were tested on a maintenance plus type visuo-spatial working memory task. The task required participants to recall a sequence of specially marked cells in a four-by-four matrix display while at the same time performing a concurrent visual judgement task. Both the current and former user groups registered impairments relative to nonusers. These remained significant following statistical controls for a range of potentially confounding variables including the use of various other drugs during the 3 months prior to testing. Users were unimpaired on a simple spatial span measure suggesting that the deficits observed reflected the executive aspects of the spatial working memory task. Also consistent with executive involvement, statistical controls for measures of verbal working memory performance (computation span) removed half of the ecstasy-related variance in spatial working memory. The possibility that the pattern of results obtained might reflect some general impairment in information processing efficiency is discussed.

Patients with schizophrenia exhibit impairments in working memory that often appear in attenuated form in persons at high risk for the illness. The authors hypothesized that deviations in task-related brain activation and deactivation would occur in persons with an at-risk mental state performing a working memory task that entailed the maintenance and manipulation of letters. Participants at ultra high risk for developing psychosis (N=60), identified using the Comprehensive Assessment of At-Risk Mental States, and healthy comparison subjects (N=38) 14 to 29 years of age underwent functional MRI while performing a verbal working memory task. Group differences in brain activation were identified using analysis of covariance. The two groups did not show significant differences in speed or accuracy of performance, even after accounting for differences in education. Irrespective of task condition, at-risk participants exhibited significantly less activation than healthy comparison subjects in the left anterior insula. During letter manipulation, at-risk persons exhibited greater task-related deactivation within the default-mode network than comparison subjects. Region-of-interest analysis in the at-risk group revealed significantly greater right dorsolateral prefrontal cortex activation during manipulation of letters. Despite comparable behavioral performance, at-risk participants performing a verbal working memory task exhibited altered brain activation compared with healthy subjects. These findings demonstrate an altered pattern of brain activation in at-risk persons that contains elements of reduced function as well as compensation.

Auditory mismatch negativity (MMN) is a biomarker for schizophrenia thought to reflect glutamatergic N-methyl-d-aspartate receptor function and excitatory-inhibitory neurotransmission balance. However, the association of glutamate level with MMN has not been directly examined in patients with schizophrenia, to our knowledge. To investigate the contributions of glutamate and γ-aminobutyric acid (GABA) to MMN and digit sequencing task (DST) performance, an assessment of verbal working memory, in schizophrenia. Fifty-three control participants from the community and 45 persons with schizophrenia from outpatient clinics completed an electroencephalographic session for MMN, magnetic resonance spectroscopy for glutamate and GABA, and a DST. The study dates were July 2011 to May 2014, and the dates of our analysis were May 2014 to August 2015. Glutamate, GABA, the ratio of glutamine to glutamate, MMN amplitude, and DST. Structural equation modeling was used to test the effects of neurochemistry and MMN amplitude on DST performance. The 45 persons with schizophrenia were a mean (SD) of 37.7 (12.8) years and the control participants were 37.1 (13.1) years. The schizophrenia group had a mean (SD) of 14.7 (12.1) years of illness. Mismatch negativity amplitude (F = 4.39, P = .04) and glutamate (F = 9.69, P = .002) were reduced in the schizophrenia group. Smaller MMN amplitude was significantly associated with lower GABA level (P = .008), lower glutamate level (P = .05), and higher ratio of glutamine to glutamate (P = .003). Reduced MMN amplitude was linked to poor verbal working memory in schizophrenia (P = .002). Modeling revealed that a proxy of glutamatergic function, indexed by the ratio of glutamine to glutamate, influenced a path from the ratio of glutamine to glutamate to MMN to verbal working memory (P = .38 [root-mean-square error of approximation, P < .001] by χ2 test), supporting the contention that MMN serves as an intermediate biomarker linking glutamatergic function to DST performance in schizophrenia. The role of glutamate and GABA in MMN and verbal working memory deficits in schizophrenia has been frequently debated. These data provide in vivo evidence that support glutamatergic and GABAergic regulation of MMN and verbal working memory function in schizophrenia.

Working memory is made up of three components, the central executive, the phonological loop, the visuo - spatial scratch - pad. Working memory can be strengthened by working on any of these individually or in coherence. This longitudinal study was conducted to access the impact of visuospatial stimulation through the use of jigsaw puzzle on verbal working memory as reflected by digit span.32 adults with minimum ability to recognise numbers, cleaved in two groups, 20 - 25 years as young adults in group I and above 60 years older adults in group II. Digit forward span and backward span was examined pre and post visuo - spatial stimulation in each group, and the results revealed that practice of visuo - spatial stimulation has improvement in verbal working memory. There was significant difference between pre - evaluation and post evaluation after some amount of visuo - spatial stimulation practice in digit forward and backward verbal working memory span in both groups. As people with Downs syndrome have a specific impairment in short - term memory for verbal information the study propose that this domain can be improved by working on the visuo - spatial domain which is already a stronger suit for people with Downs syndrome.

Younger and older adults who were either monolingual or bilingual were tested with verbal and spatial working memory (WM) span tasks. Aging was associated with a greater decline in spatial WM than in verbal WM, but the age-related declines were equivalent in both language groups. The bilingual participants outperformed the monolinguals in spatial WM, but achieved lower levels of performance than monolinguals in verbal WM. This interaction between bilingualism and WM domain was also consistent across the adult life span. These results are discussed in terms of the interactions between a domain-general executive processing advantage for bilinguals and the domain-specific content of particular WM tasks.

Neuropsychological findings together with recent advances in neuroanatomical and neuroimaging techniques have spurred the investigation of cerebellar contributions to cognition. One cognitive process that has been the focus of much research is working memory, in particular its verbal component. Influenced by Baddeley's cognitive theory of working memory, cerebellar activation during verbal working memory tasks has been predominantly attributed to the cerebellum's involvement in an articulatory rehearsal network. Recent neuroimaging and neuropsychological findings are inconsistent with a simple motor view of the cerebellum's function in verbal working memory. The present article examines these findings and their implications for an articulatory rehearsal proposal of cerebellar function. Moving beyond cognitive theory, we propose two alternative explanations for cerebellar involvement in verbal working memory: Error-driven adjustment and internal timing. These general theories of cerebellar function have been successfully adapted from the motor literature to explain cognitive functions of the cerebellum. We argue that these theories may also provide a useful framework to understand the non-motor contributions of the cerebellum to verbal working memory.

Individuals with public speaking phobia experience fear and avoidance that can cause extreme distress, impaired speaking performance, and associated problems in psychosocial functioning. Most extant interventions for public speaking phobia focus on the reduction of anxiety and avoidance, but neglect performance. Additionally, very little is known about the relationship between verbal working memory and social performance under conditions of high anxiety. The current study compared the efficacy of two cognitive behavioral treatments, traditional Cognitive Behavioral Therapy (tCBT) and acceptance-based behavior therapy (ABBT), in enhancing public speaking performance via coping with anxiety. Verbal working memory performance, as measured by the backwards digit span (BDS), was measured to explore the relationships between treatment type, anxiety, performance, and verbal working memory. We randomized 30 individuals with high public speaking anxiety to a 90-minute ABBT or tCBT intervention. As this pilot study was underpowered, results are examined in terms of effect sizes as well as statistical significance. Assessments took place at pre and post-intervention and included self-rated and objective anxiety measurements, a behavioral assessment, ABBT and tCBT process measures, and backwards digit span verbal working memory tests. In order to examine verbal working memory during different levels of anxiety and performance pressure, we gave each participant a backwards digit span task three times during each assessment: once under calm conditions, then again while experiencing anticipatory anxiety, and finally under conditions of acute social performance anxiety in front of an audience. Participants were asked to give a video-recorded speech in front of the audience at pre- and post-intervention to examine speech performance. Results indicated that all participants experienced a very large and statistically significant decrease in anxiety (both during the speech and BDS), as well as an improvement in speech performance vii regardless of intervention received. While not statistically significant, participants who received an acceptance-based intervention exhibited larger improvements in observer-rated speech performance at post-treatment in comparison to tCBT (F (1,21) = 1.91, p =.18, [eta][p]2 = .08) such that individuals in the ABBT condition exhibited a considerably greater improvement in observer-rated speech performance than those in the tCBT condition. There was no differential impact of treatment condition on subjective speech anxiety or working memory task performance. Potential mediators and moderators of treatment were also examined. Results provide support for a brief 90-minute intervention for public speaking anxiety, but more research is needed in a study with a larger sample to fully understand the relationship between ABBT strategies and improvements in behavioral performance.

Characterization of a normal control group: Are they healthy?