Auditory Verbal Working Memory Research Articles

Two are better than one: Differences in cortical EEG patterns during auditory and visual verbal working memory processing between Unilateral and Bilateral Cochlear Implanted children

Despite the proven effectiveness of cochlear implant (CI) in the hearing restoration of deaf or hard-of-hearing (DHH) children, to date, extreme variability in verbal working memory (VWM) abilities is observed in both unilateral and bilateral CI user children (CIs). Although clinical experience has long observed deficits in this fundamental executive function in CIs, the cause to date is still unknown. Here, we have set out to investigate differences in brain functioning regarding the impact of monaural and binaural listening in CIs compared with normal hearing (NH) peers during a three-level difficulty n-back task undertaken in two sensory modalities (auditory and visual). The objective of this pioneering study was to identify electroencephalographic (EEG) marker pattern differences in visual and auditory VWM performances in CIs compared to NH peers and possible differences between unilateral cochlear implant (UCI) and bilateral cochlear implant (BCI) users. The main results revealed differences in theta and gamma EEG bands. Compared with hearing controls and BCIs, UCIs showed hypoactivation of theta in the frontal area during the most complex condition of the auditory task and a correlation of the same activation with VWM performance. Hypoactivation in theta was also observed, again for UCIs, in the left hemisphere when compared to BCIs and in the gamma band in UCIs compared to both BCIs and NHs. For the latter two, a correlation was found between left hemispheric gamma oscillation and performance in the audio task. These findings, discussed in the light of recent research, suggest that unilateral CI is deficient in supporting auditory VWM in DHH. At the same time, bilateral CI would allow the DHH child to approach the VWM benchmark for NH children. The present study suggests the possible effectiveness of EEG in supporting, through a targeted approach, the diagnosis and rehabilitation of VWM in DHH children.

Auditory naming is impaired in posterior cortical atrophy and early-onset Alzheimer's disease.

Visual naming ability reflects semantic memory retrieval and is a hallmark deficit of Alzheimer's disease (AD). Naming impairment is most prominently observed in the late-onset amnestic and logopenic variant Primary Progressive Aphasia (lvPPA) syndromes. However, little is known about how other patients across the atypical AD syndromic spectrum perform on tests of auditory naming, particularly those with primary visuospatial deficits (Posterior Cortical Atrophy; PCA) and early onset (EOAD) syndromes. Auditory naming tests may be of particular relevance to more accurately measuring anomia in PCA syndrome and in others with visual perceptual deficits. Forty-six patients with biomarker-confirmed AD (16 PCA, 12 lvPPA, 18 multi-domain EOAD), at the stage of mild cognitive impairment or mild dementia, were administered the Auditory Naming Test (ANT). Performance differences between groups were evaluated using one-way ANOVA and post-hoc t-tests. Correlation analyses were used to examine ANT performance in relation to measures of working memory and word retrieval to elucidate cognitive mechanisms underlying word retrieval deficits. Whole-cortex general linear models were generated to determine the relationship between ANT performance and cortical atrophy. Based on published cutoffs, out of a total possible score of 50 on the ANT, 56% of PCA patients (mean score = 45.3), 83% of EOAD patients (mean = 39.2), and 83% of lvPPA patients (mean = 29.8) were impaired. Total uncued ANT performance differed across groups, with lvPPA performing most poorly, followed by EOAD, and then PCA. ANT performance was still impaired in lvPPA and EOAD after cuing, while performance in PCA patients improved to the normal range with phonemic cues. ANT performance was also directly correlated with measures of verbal fluency and working memory, and was associated with cortical atrophy in a circumscribed semantic language network. Auditory confrontation naming is impaired across the syndromic spectrum of AD including in PCA and EOAD, and is likely related to auditory-verbal working memory and verbal fluency which represent the nexus of language and executive functions. The left-lateralized semantic language network was implicated in ANT performance. Auditory naming, in the absence of a visual perceptual demand, may be particularly sensitive to measuring naming deficits in PCA.

The dynamics of auditory working memory impairment in logopenic aphasia and Alzheimer’s disease

AbstractBackgroundImpaired auditory verbal working memory is a diagnostic hallmark and integral driver of the clinical phenotype in logopenic aphasia. However, the physiology of the working memory buffer in this syndrome is poorly characterised. Here we addressed the temporal dynamics of auditory verbal working memory in patients with logopenic aphasia and typical Alzheimer’s disease.MethodIn a cohort of patients with logopenic aphasia and typical Alzheimer’s disease and in healthy age‐matched controls, we assessed how temporal manipulations of standard auditory verbal working memory tasks (forward and reverse digit span and phrasal repetition) affected performance. We varied tempo of delivery and inter‐trial gap and performed a detailed analysis of error types. Participants also had pure tone audiometry to assess peripheral hearing function and a comprehensive general neuropsychological assessment.ResultCompared with healthy controls, patients with logopenic aphasia and Alzheimer’s disease showed increased sensitivity to temporal manipulation of auditory verbal working memory tasks and error profiles suggesting a dynamic physiological lesion of the working memory buffer. These effects were particularly marked in the logopenic group.ConclusionOur findings open a novel physiological window on working memory dynamics in Alzheimer’s disease syndromes. Further work is warranted to assess how this dynamic deficit impacts communication in patients’ daily lives, how it can best inform management interventions and its potential as a novel, rapid read‐out of neural function in the era of disease‐modifying therapies.

73 Examining the Associations Between Sentence Repetition and Other Cognitive Abilities in a Clinical Sample of School-Aged Children

Objective:Sentence repetition (SR) task performance is related to various cognitive abilities and not just learning and memory, as is commonly considered (e.g., Baron, 2018). Bartlett (2018) was the first to examine the associations among SR performance and other cognitive abilities within a single study, using a normative sample. Bartlett (2018) found that SR performance was predicted by language, auditory verbal working memory, processing speed, and nonverbal cognitive ability of which only language abilities and auditory verbal memory significantly added to the prediction. However, no study to date has examined the associations between SR and other cognitive abilities in a clinical sample of school-aged children. The present study sought to determine the extent to which language, working memory, nonverbal abilities (visuospatial processing and fluid reasoning), and processing speed predict children’s SR in a clinical sample.Participants and Methods:Children 6 to 14 years of age (N = 191; 65% males) were included in the present study. Participants were drawn from two separate archival data populations of children referred for neuropsychological assessment in southwestern Ontario. SR scores were obtained from performance on Benton’s (1965) sentence repetition task. Language, working memory, fluid reasoning, visual perception, and processing speed were measured with Index scores from the Wechsler Intelligence Scale for Children (5th edition). The association of each of these cognitive domains with SR was determined by multiple linear regression. The effects of age and sex on SR were also examined (N = 226; 64% males).Results:A multiple linear regression model including the five independent variables significantly predicted SR performance, F(5, 185) = 30.306, p < .001., adj. R2 = .435. Only language and working memory added significantly to the prediction, p < .05. A mediation analysis demonstrated that processing speed indirectly predicted SR performance through working memory, b=.0241, [95% BCa [CI .0132, .0355]. A moderate positive correlation was found between age and SR performance, r(226) = .416, p < .001. Sex was unrelated to SR performance.Conclusions:The findings from this study are consistent with other studies indicating that SR taps multiple cognitive abilities. In a large and representative clinical sample of children referred for assessment due to academic or other learning difficulties, language plays as significant a role in SR performance as does auditory verbal attention and working memory. An advantage of the present study was the use of clinically relevant summary measures of cognitive domains associated with intelligence testing.

Assessment of the relationship between bilingualism indicators and indicators of cognitive and emotional development of children of senior preschool age

This article is devoted to assessing the relationship between indicators of bilingualism and indicators of cognitive and emotional development in preschool children. Various measures were used to assess the level of bilingualism, including active language proficiency, comprehension, and switching between languages. During the study, it was found that the level of auditory-verbal intelligence remained at an average level, although the level of visual working memory turned out to be higher in children studying in the Yakut language. Children who study in the Yakut language showed higher visual working memory scores. However, the levels of development of auditory-verbal working memory were at an average level. In children who study in the Yakut language, the auditory-verbal memory turned out to be lower compared to visual memory. In children studying in Russian, the auditory-verbal working memory was more highly developed, while the level of cognitive control associated with restraining momentary manifestations and reactions corresponded to the age norms. Physical control was at a fairly high level. Also, during the diagnostic process, data were obtained on the emotional development of children. Children who master the Russian language during the learning process showed better results.

Differences in auditory verbal working memory between adults who do and do not stutter on an N-back task

PurposeThe purpose of this study was to investigate auditory verbal working memory in adults who do (AWS) and do not (AWNS) stutter using a highly demanding linguistic N-back task. MethodsFifteen AWS and 15 AWNS matched in age, gender and educational level were asked to hear series of words and respond by pressing a “yes” button if the word they just heard was the same as the word one, two, or three trials back. Words were either phonologically similar (i.e., Phonological Linguistic Condition) or phonologically dissimilar (i.e., Neutral Linguistic Condition). Accuracy and false alarms rates as well as reaction time on correct target trials, missed target trials and false alarms were collected and analyzed. ResultsDifferences were not found between AWS and AWNS in accuracy. Both groups were more accurate and significantly faster in 1- followed by 2- followed by 3-back trials. However, AWS were significantly slower than AWNS in the 2-back level, regardless of linguistic condition. Furthermore, AWS demonstrated more false alarms compared to AWNS. ConclusionResults revealed differences in auditory verbal working memory and interference control between AWS and AWNS when processing highly linguistically demanding stimuli.

The effect of working memory load on inattentional deafness during aeronautical decision-making

Operating an aircraft requires pilots to handle a significant amount of multi-modal information, which creates a high working memory load. Detecting auditory alarms in this high-load scenario is crucial for aviation safety. According to cognitive control load theory, an increase in working memory load may enhance distractor interference, resulting in improved detection sensitivity for task-irrelevant stimuli. Therefore, understanding the effect of working memory load on auditory alarm detection is of particular interest in aviation safety research. The studies were designed to investigate the effect of storage load and executive function load of working memory on auditory alarm detection during aeronautical decision-making through three experiments. In Experiment 1 and 2, participants performed an aeronautical decision-making task while also detecting an auditory alarm during the retention interval of a working memory task (visual-spatial, visual-verbal and auditory-verbal). In Experiment 3, participants were required to detect an auditory alarm while performing the 2-back and 3-back aeronautical decision-making tasks. Experiment 1 found that the auditory alarm sensitivity was higher in conditions of low visual-spatial working memory storage load compare to high load conditions. Experiment 2 found that a high storage load of visual-verbal working memory reduced auditory alarm sensitivity but auditory-verbal working memory load did not. Experiment 3 found that, unlike storage load, auditory alarm sensitivity was stronger under high executive function load relative to low executive function load. These findings show that working memory storage load and executive function load have different effects on auditory alarm sensitivity. The relationship between executive function and auditory alarm sensitivity supports cognitive control load theory, while the impact of the storage function on auditory alarm sensitivity does not adhere to this theory.

Attention and working memory in patients with prolactinomas: a case–control study

Prolactinomas (prolactin-secreting adenomas) are the most common type of hormone-secreting pituitary tumor. Mounting evidence indicates that excess prolactin impairs cognitive function, but specific assessments of attention in patients with prolactinomas are lacking. Case–control study gathered 54 participants—27 patients with prolactinoma and 27 healthy controls. Neuropsychological assessment included a comprehensive set of diagnostic methods for the evaluation of attention and working memory. Patients showed slower information processing, expressed as a longer working time on the d2 Test of Attention and Color Trails Test (CTT-2), and lower attention-switching shown in the CTT-2 and in two subtests of the Tests of Everyday Attention (Visual Elevator), and Telephone Search While Counting. Working memory disturbances were observed in Digit Span and Symbol Span tests. A level of prolactin correlated negatively with scores in some of the neuropsychological tests measuring attentional switching (Visual Elevator), spatial screening and working memory (CTT-2), spatial working memory (Symbol Span) and auditory-verbal working memory (Digit Span backwards). There were no significant correlations between cognitive performance and tumor size. In conclusion, patients with prolactinoma suffer from impaired cognitive functions, including attention and working memory. Comprehensive neuropsychological assessment should be a permanent element of the diagnostics of this group of patients.

The effect of anxiety on working memory and language abilities in elementary schoolchildren with and without Additional Health and Developmental Needs.

Although excessive childhood anxiety is recognised as a significant public health, education and socioeconomic concern, the specific effects of such anxiety on language development and working memory, particularly visual working memory, are relatively unknown. Thus, this study aimed to examine parent-reported trait anxiety, parent-reported functional language (daily communication skills) and clinical measures of non-verbal intelligence, receptive and expressive vocabulary, phonological awareness, and visual and auditory-verbal short-term and working memory in elementary schoolchildren. The final sample included 41 children categorised as Additional Health and Developmental Needs (AHDN) due to medical, neurodevelopmental or educational concerns and 41 age- and IQ-matched neurotypical (NT) children, aged 5- to 9-years. Results showed that 26% of all children in our entire sample (AHDN and NT) experienced moderate, sub-clinical anxiety (as reported by parents), and that AHDN children were 10.5 times more likely to experience high anxiety than the NT group (odds ratio). Parents of AHDN children reported lower functional language in their children than parents of NT children. Cognitive testing indicated that the AHDN group also had poorer visual and auditory-verbal working memory than the NT group. Further, High Anxiety children (drawn from both AHDN and NT groups) showed poorer parent-reported functional language skills, and lower visual and auditory-verbal working memory capacities. Our findings are amongst the first to confirm that the presence of high parent-rated trait anxiety is associated with reduced visual working memory in children, which is consistent with biological and theoretical expectations of the impact of anxiety on visually driven, goal-directed attention and working memory. Our results regarding the high prevalence of sub-clinical anxiety in both ADHD and neurotypical children highlight the need for early assessment of anxiety in all schoolchildren, especially those classified as AHDN.

Gamma-Band Modulation in Parietal Area as the Electroencephalographic Signature for Performance in Auditory-Verbal Working Memory: An Exploratory Pilot Study in Hearing and Unilateral Cochlear Implant Children.

This pilot study investigates the neurophysiological patterns of visual and auditory verbal working memory (VWM) in unilateral cochlear implant users (UCIs). We compared the task-related electroencephalogram (EEG) power spectral density of 7- to 13-year-old UCIs (n = 7) with a hearing control group (HC, n = 10) during the execution of a three-level n-back task with auditory and visual verbal (letters) stimuli. Performances improved as memory load decreased regardless of sensory modality (SM) and group factors. Theta EEG activation over the frontal area was proportionally influenced by task level; the left hemisphere (LH) showed greater activation in the gamma band, suggesting lateralization of VWM function regardless of SM. However, HCs showed stronger activation patterns in the LH than UCIs regardless of SM and in the parietal area (PA) during the most challenging audio condition. Linear regressions for gamma activation in the PA suggest the presence of a pattern-supporting auditory VWM only in HCs. Our findings seem to recognize gamma activation in the PA as the signature of effective auditory VWM. These results, although preliminary, highlight this EEG pattern as a possible cause of the variability found in VWM outcomes in deaf children, opening up new possibilities for interdisciplinary research and rehabilitation intervention.

Age-Related Differences of Mandarin Tone and Consonant Aspiration Perception in Babble Noise.

This study investigated the categorical perception of Mandarin tones and consonant aspiration contrasts in babble noise among adults and adolescents aged 12-14 years, and explored the association between working memory and categorical perception. Twenty-four adults and 20 adolescents with Mandarin as their native language were recruited. Their performances of phonemic identification and discrimination in babble noise and quiet conditions, digit span tasks, and nonword repetition were assessed. Results indicated that, firstly, in the noise condition, both adults and adolescents showed wider boundary widths and lower between-category accuracies when perceiving aspiration of consonants than in the quiet condition, and the categorical boundary of tone perception in adolescents showed a transitional tendency toward Tone 1. Secondly, discrimination of consonant aspiration in adolescents needed to be further developed. Lastly, the accuracy of nonword repetition in adolescents was lower than that in adults, and adults with better auditory verbal working memory had better performance on tone perception. Our results provided evidence that tone perception is acquired easier than consonant aspiration perception, and tone perception is more robust and less susceptible to noise interference. Categorical perception performance relates to the capacity and utilization of auditory verbal working memory in some ways.

Long-lasting, dissociable improvements in working memory and long-term memory in older adults with repetitive neuromodulation.

The development of technologies to protect or enhance memory in older people is an enduring goal of translational medicine. Here we describe repetitive (4-day) transcranial alternating current stimulation (tACS) protocols for the selective, sustainable enhancement of auditory-verbal working memory and long-term memory in 65-88-year-old people. Modulation of synchronous low-frequency, but not high-frequency, activity in parietal cortex preferentially improved working memory on day 3 and day 4 and 1 month after intervention, whereas modulation of synchronous high-frequency, but not low-frequency, activity in prefrontal cortex preferentially improved long-term memory on days 2-4 and 1 month after intervention. The rate of memory improvements over 4 days predicted the size of memory benefits 1 month later. Individuals with lower baseline cognitive function experienced larger, more enduring memory improvements. Our findings demonstrate that the plasticity of the aging brain can be selectively and sustainably exploited using repetitive and highly focalized neuromodulation grounded in spatiospectral parameters of memory-specific cortical circuitry.

120  Impaired phonemic discrimination in logopenic variant primary progressive aphasia

BackgroundWhilst current diagnostic criteria for primary progressive aphasia syndromes (PPA) emphasise impaired language output and linguistic processing, deficits of auditory analysis are increasingly rec- ognised in PPA syndromes. We assessed phonemic discrimination and its neuroanatomical correlates in patients representing all major PPA variants, compared with typical Alzheimer’s disease (tAD) and healthy age-matched individuals.Methods81 patients with PPA or typical Alzheimer’s disease, and 73 controls performed a phonemic minimal pair discrimination task. Neuroanatomical associations of phonemic discrimination performance across the PPA cohort were assessed using voxel-based morphometry.ResultsPatients with logopoenic variant primary progressive aphasia (lvPPA) as a group performed sig- nificantly worse than both the healthy control group and other PPA variants, after adjusting for auditory verbal working memory. Patients with typical Alzheimer’s disease showed a similar pattern of performance to the lvPPA group. Voxel-based morphometry revealed a significant association of regional grey matter in left angular gyrus with phonemic discrimination performance.ConclusionsImpaired phonemic discrimination is a component of lvPPA and may help differentiate this syndrome from other forms of PPA. These findings speak to the emerging theme of auditory perceptual dysfunction in the progressive aphasias, with implications both for refining diagnostic criteria and developing new clinical biomarkers.jeremy.johnson@doctors.org.uk

Features of the Construction of Children Narratives in a Bilingual Environment

The article examines such an indicator of the development of language and culture as a childs elicited narrative. A narrative is a story created by a child based on a picture story or a series of pictures. The narrative allows to evaluate the childs coherent monologue speech. Narratives as primary forms of cultural texts reflect a certain national and cultural specifics. In the narrative, one can distinguish a macrostructure that determines its semantic completeness and adequacy, as well as a microstructure that assess lexical and grammatical accuracy. In our work, we studied the narratives of children from Moscow, the Republic of Sakha - Yakutia (Yakutsk and uluses) and the Republic of Tatarstan (Kazan). In addition, children performed a number of psychological tests, which made it possible to assess their level of development of executive functions and non-verbal intelligence. The main objective of the study was to identify how the factor of bilingualism influences the construction of the narrative and what other factors also influence. The study involved 765 children, including 327 boys and 438 girls ( M = 77.89 months, SD = 5.22). All children attended senior groups of kindergartens in Moscow ( n = 495), Kazan ( n = 115), the Republic of Sakha-Yakutia (Yakutsk and uluses) ( n = 155). As a result of a survey of educators and a short language test, the sample was divided into two groups: bilinguals ( n = 179 people) who communicate equally in Russian and national languages; and monolinguals (586 people) who communicate mainly or only in Russian. The results of statistical processing of the material showed that bilingualism is an important factor affecting the microstructure of narratives, however, to the greatest extent, both micro and macrostructure depend on auditory-verbal working memory. This is supported by both correlations and general linear models.

Comparison of Resting-State Brain Activation between Healthy Normal and Low Auditory-Verbal Working Memory Capacity Participants

Working memory (WM) capacity is the ability to maintain attention and store information briefly in the mind. However, each individual has a limited WM capacity that varies from one person to another. An individual can be categorized as having either normal or low WM capacity. This study aimed to evaluate and compare brain activations of healthy individuals with low and normal auditory-verbal WM capacity. A total of 39 healthy male young adults were recruited from local universities for this study. They were categorized into the normal and low auditory-verbal WM capacity group based on their score in the Malay Version of Auditory Verbal Learning Test (MVAVLT). All participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans. The functional data were analyzed using Statistical Parametric Mapping (SPM) and Wake Forest University (WFU) Pickatlas softwares. Brain activations and resting-state amplitude fluctuation (rsAF) were contrasted between groups to determine whether there were any significant differences caused by the different auditory-verbal WM capacity. The findings indicated that the low auditory-verbal WM capacity group showed significantly higher cortical activations in the left lingual gyrus, bilateral middle temporal gyrus, left calcarine, left superior frontal gyrus, and left precuneus as compared to normal auditory-verbal WM capacity group. It is suggested that the higher activation of these brain areas in low verbal-auditory WM capacity participants was attributed to the lower neural adaptability of the brain at rest.

Auditory-verbal memory function of women during the menstruation and ovulation periods

Background and Aim: Auditory-verbal mem­ory (AVM) is the ability to learn, retain, and recall syllables and words. Memory has a strong relationship with the nervous and endocrine systems in humans. Changes in estrogen levels occur naturally at short (menstrual period) and long (pregnancy, menopause, and maturity) peri­ods. Changes in estrogen levels are likely to affect memory function. This study aimed to evaluate the effects of hormone fluctuations on the AVM of women.
 Methods: This cross-sectional study with a pretest/posttest design was conducted on 25 women aged 40−49 years with normal hearing and normal menstrual cycles of 28 ± 4 days, who were selected using a convenience sampling method. They were evaluated using two Persian versions of Rey Auditory-Verbal Learning Test (RAVLT). This test was performed twice and at two different menstrual periods (2-5 and 14−16 days).
 Results: A significant correlation was observed between the mean of total recall score, recall score after interference, and delayed recall score at two different periods (p < 0.01). The scores of women in three areas on days 14−16 of the menstrual cycle were higher than on days 2−5.
 Conclusion: Women’s RAVLT scores on days 14−16 of the menstrual cycle are higher than on days 2−5, indicating the effect of hormonal fluc­tuations on their AVM function. Therefore, it is necessary to consider the changes in women’s AVM in different days of the menstrual cycle.
 Keywords: Auditory-verbal working memory; Rey learning test; menstrual cycle
  

Obstacle Avoidance and Dual-Tasking During Reaching While Standing in Patients With Mild Chronic Stroke

Background. Poststroke individuals use their paretic arms less often than expected in daily life situations, even when motor recovery is scored highly in clinical tests. Real-world environments are often unpredictable and require the ability to multitask and make decisions about rapid and accurate arm movement adjustments. Objective. To identify whether and to what extent cognitive–motor deficits in well-recovered individuals with stroke affect the ability to rapidly adapt reaching movements in changing cognitive and environmental conditions. Methods. Thirteen individuals with mild stroke and 11 healthy controls performed an obstacle avoidance task in a virtual environment while standing. Subjects reached for a virtual juice bottle with their hemiparetic arm as quickly as possible under single- and dual-task conditions. In the single-task condition, a sliding glass door partially obstructed the reaching path of the paretic arm. A successful trial was counted when the subject touched the bottle without the hand colliding with the door. In the dual-task condition, subjects repeated the same task while performing an auditory–verbal working memory task. Results. Individuals with stroke had significantly lower success rates than controls in avoiding the moving door in single-task (stroke: 51.8 ± 21.2%, control: 70.6 ± 12.7%; P = .018) and dual-task conditions (stroke: 40.0 ± 27.6%, control: 65.3 ± 20.0%; P = .015). Endpoint speed was lower in stroke subjects for successful trials in both conditions. Obstacle avoidance deficits were exacerbated by increased cognitive demands in both groups. Individuals reporting greater confidence using their hemiparetic arm had higher success rates. Conclusion. Clinically well-recovered individuals with stroke may have persistent deficits performing a complex reaching task.

Comparing verbal working memory load in auditory and visual modalities using functional near-infrared spectroscopy

The verbal identity n-back task is commonly used to assess verbal working memory (VWM) capacity. Only three studies have compared brain activation during the n-back when using auditory and visual stimuli. The earliest study, a positron emission tomography study of the 3-back, found no differences in VWM-related brain activation between n-back modalities. In contrast, two subsequent functional magnetic resonance imaging (fMRI) studies of the 2-back found that auditory VWM was associated with greater left dorsolateral prefrontal cortex (DL-PFC) activation than visual VWM, perhaps suggesting that auditory VWM requires more cognitive effort than its visual counterpart. The current study aimed to assess whether DL-PFC activation (i.e., cognitive effort) differs by VWM modality. To do this, 16 younger adults completed an auditory and visual n-back, both at four levels of VWM load. Concurrently, activation of the PFC was measured using functional near-infrared spectroscopy (fNIRS), a silent neuroimaging method. We found that DL-PFC activation increased with VWM load, but it was not affected by VWM modality or the interaction between load and modality. This supports the view that both VWM modalities require similar cognitive effort, and perhaps that previous fMRI results were an artefact of scanner noise. We also found that, across conditions, DL-PFC activation was positively correlated with reaction time. This may further support DL-PFC activation as an index of cognitive effort, and fNIRS as a method to measure it.

The Girl Was Watered by the Flower: Effects of Working Memory Loads on Syntactic Production in Young Children

ABSTRACT Working memory is necessary for a wide variety of cognitive abilities. Developmental work has shown that as working memory capacities increase, so does the ability to successfully perform other cognitive tasks, including language processing. The present work demonstrates the effects of working memory availability on children’s language production. Whereas most of the previous research linking working memory to language development has been correlational, we experimentally varied the working memory load during concurrent language production in children 4–5 years old. Participants were asked to describe simple picture scenes that had recently been described for them in the relatively unfamiliar, passive voice (e.g., the flower was watered by the girl). Children frequently produced the passive voice, a form of syntactic priming. These responses were performed while children sometimes retained a visual-spatial or auditory-verbal working memory load to be recalled after sentence production but there was no effect of the load on syntactic priming. In a second experiment, after hearing passive-voice descriptions of pictures, instead of relying on priming, the children were directly asked to describe the same pictures by speaking in the same “special way.” Surprisingly, under a load, children more often used the passive voice as they were instructed to do, but at the expense of producing additional semantic and grammatical errors (including some nonsensical renditions such as the girl was watered by the flower). We propose that working memory, when available, is used to impose a quality-control process whereby the semantic fidelity of the response to the stimulus picture is preserved, here at the expense of disregarding the experimental instruction to reproduce the passive voice.

Modality effects in verbal working memory updating: Transcranial direct current stimulation over human inferior frontal gyrus and posterior parietal cortex

Verbal working memory (VWM) involves visual and auditory verbal information. Neuroimaging studies have shown significant modality effects for VWM in the left posterior parietal cortex (PPC). The left inferior frontal gyrus (IFG) is more sensitive to auditory and phonological information. However, much less is known about the effects of transcranial direct current stimulation (tDCS) over the left PPC and IFG on different sensory modalities of VWM (auditory vs. visual). Therefore, the present study aimed to examine whether tDCS over the left PPC and IFG affects visual and auditory VWM updating performance using a single-blind design. Fifty-one healthy participants were randomly assigned to three tDCS groups (left PPC/left IFG/sham) and were asked to complete both the visual and auditory letter 3-back tasks. Results showed that stimulating the left PPC enhanced the response efficiency of visual, but not auditory, VWM compared with the sham condition. Anodal stimulation to the left IFG improved the response efficiency of both tasks. The present study revealed a modality effect of VWM in the left PPC, while the left IFG had a causal role in VWM updating of different sensory modalities.