Auditory Comprehension Research Articles (Page 1)

Direct electrical stimulation (DES) remains the gold standard for identifying eloquent language cortex. However, most protocols rely on single-task mapping, typically visual naming, potentially overlooking modality-specific or distributed language areas. The aim of this study was to define the spatial extent of polyfunctional language cortex using multitask DES integrated with the Yale Brain Atlas (YBA) and to supplement this with population-based structural connectivity data. We retrospectively analyzed patients with drug-resistant focal epilepsy who underwent intracranial EEG monitoring and extraoperative DES language mapping at Yale (2017-2022). Six tasks were administered at each bipolar contact pair: visual naming, auditory naming, reading, repetition, auditory comprehension, and written comprehension. Responses were mapped to the YBA (∼1-cm2 resolution), normalized for amperage and sampling frequency, and aggregated across patients. Intertask correlations were assessed using Kendall rank coefficients. Structural connectivity between language-involved parcels was evaluated using deterministic tractography from diffusion data of 1,065 healthy participants. Analyses were conducted using Python 3.9.13. Fifteen patients were included (mean age, 42.8 ± 14.1 years; 53% male). Multitask mapping identified a reproducible "language core" involving the superior temporal gyrus, pars triangularis, anterior supramarginal gyrus, and a basal temporal area located 4-6 cm posterior to the temporal tip. A tiered task strategy-visual naming, auditory naming, and reading-captured over 99% of all language-positive sites. At the individual level, up to 16% (8.2%-15.9%) of parcels cleared by visual naming alone exhibited disruption with other tasks, notably reading. Intertask correlation was highest between auditory naming and visual naming (p < 0.0001, τ = 0.70, 95% CI 0.61-0.78). Structural connectivity analysis showed involvement of the arcuate fasciculus (76.9%), parietal aslant tract (85.4%), and superior longitudinal fasciculus (73.9%). The supramarginal region had the densest language connectivity (69.2%), although connectivity strength did not correlate with DES-defined language involvement (τ = -0.14, p = 0.11). Multitask DES anchored to the YBA provides an anatomically precise, reproducible platform for language mapping. A focused task set enhances efficiency without sacrificing sensitivity. Integration with structural connectivity offers network-level insights. Limitations include modest sample size, variable electrode coverage with undersampling of the anterior language areas, and patient population with epilepsy, which may affect generalizability. This multimodal framework informs surgical planning and advances our understanding of human language representation.

An exploratory study and new model of the role of implicit timing in sentence comprehension.

Repetitive transcranial magnetic stimulation (rTMS) is a promising intervention for language recovery in post-stroke aphasia, yet the efficacy of different frequency protocols remains to be fully understood. This study aims to explore the efficacy of high versus low-frequency rTMS on language recovery in post-stroke aphasia. In this retrospective cohort study, 194 patients with post-stroke aphasia who underwent rTMS treatment from December 2019 to December 2022 were analyzed. Patients were categorized into 2 groups based on the frequency of rTMS received: low frequency (≤1 Hz, n = 101) and high frequency (≥5 Hz, n = 93). National Institutes of Health Stroke Scale scores were recorded to quantify overall neurological deficits at baseline. Language outcomes were assessed using the Western Aphasia Battery-Aphasia Quotient (WAB-AQ) and the Boston Naming Test (BNT) at baseline, immediately post-treatment, and 2 months later. Adverse events were also recorded. One day post-treatment, the low-frequency rTMS group showed significantly greater improvements in WAB-AQ scores compared to the high-frequency group (P < .001), with significant enhancements in spontaneous speech, auditory comprehension, repetition, and naming (all P < .001). BNT scores also improved significantly in the low-frequency group (P = .025). At the 2-month follow-up, both groups exhibited continued improvement, but the low-frequency group maintained significantly greater gains in WAB-AQ (P < .001), BNT (P = .032), spontaneous speech (P < .001), auditory comprehension (P = .003), repetition (P = .041), and naming (P = .019). Linear mixed model analysis confirmed that low-frequency rTMS facilitated superior language recovery, with significant Time*Group interactions observed for WAB-AQ (P < .001), spontaneous speech (P < .001), auditory comprehension (P < .001), and naming (P = .034). High-frequency rTMS was associated with a higher frequency of headaches (P = .018) and scalp dysesthesia (P < .001). Serious adverse events were significantly less frequent in the low-frequency group (P < .001). Low-frequency rTMS is more effective and safer than high-frequency rTMS in improving language recovery for patients with post-stroke aphasia. These findings suggest a potential preference for low-frequency rTMS in clinical settings.

ObjectivesWhite matter hyperintensities (WMH) have been associated with the severity of post-stroke aphasia (PSA), but the contribution of overall brain health remains unclear. Brain age is a neurobiological indicator of aging that is based on whole-brain structural neuroimaging. This study investigated the impact of brain age on language function after stroke.MethodsFifty-seven patients with PSA and left-hemisphere lesions were included. The Fazekas scale was used to evaluate WMH burden, including periventricular WMH (PWMH) and deep WMH (DWMH). Brain age was estimated using structural 3D T1-weighted imaging, and the Brain-Predicted Age Difference (brain-PAD) was calculated. Multivariate linear regression and mediation analysis were conducted to examine associations among WMH burden, brain-PAD, and aphasia severity. The interaction between WMH burden and brain-PAD was also assessed.ResultsHigher levels of PWMH and DWMH were associated with increased brain-PAD in PSA patients (PWMH: p = 0.024; DWMH: p < 0.001). Mediation analysis indicated that WMH had an indirect effect on auditory comprehension via brain-PAD (PWMH: β = −9.360, p = 0.028, q = 0.042) and a direct effect on naming impairment (PWMH: β = −15.812, p = 0.030, q = 0.042; DWMH: β = −19.217, p = 0.030, q = 0.042). A significant interactive effect of PWMH burden and brain-PAD on auditory comprehension was also observed (β = −4.040, p = 0.004, q = 0.033).ConclusionOur findings highlight the influence of neuroanatomical aging and WMH burden on post-stroke language deficits, supporting the consideration of both brain-PAD and WMH severity when assessing aphasia severity to inform clinical assessment and treatment planning.

Background/Objectives: This study examines the impact of long-term institutionalization on the linguistic and communicative abilities of people diagnosed with schizophrenia, focusing on the influence of educational background. Schizophrenia is characterized by cognitive and social deficits, including disruptions to language use and communicative engagement. Prolonged institutionalization can exacerbate these impairments by depriving individuals of essential social interactions and cognitive stimulation. Methods: A case series approach was employed with 18 participants, and validated assessment tools such as the Montreal Evaluation of Communication and the Boston Diagnostic Aphasia Test were used to measure communicative performance. Results: Participants with higher educational attainment (nine or more years of schooling) who had been institutionalized for ten years or more exhibited significantly better performance than their less-educated counterparts across various communication domains, including comprehension of linguistic prosody, lexical fluency, and auditory comprehension. This implies that completing a higher degree may mitigate the cognitive decline impact of prolonged stays in an institution. However, the study design does not allow us to ascertain whether education functions as a mitigating factor. Conclusions: The results highlight the importance of incorporating educational considerations into therapeutic strategies for individuals with schizophrenia, especially those experiencing long-term institutionalization. Providing enhanced educational opportunities within institutional settings could mitigate the adverse effects of prolonged confinement and foster improved communication and social skills. These findings are consistent with research on cognitive reserve, which suggests that education fosters adaptive strategies and the utilization of alternative neural pathways. This enables individuals to maintain communication skills despite the cognitive impairment associated with schizophrenia.

Recovery from aphasia is a complex process involving restoring language ability to a level comparable to an individual’s pre-aphasia state. This recovery extends beyond linguistic functions such as improved quality of life and functional communication. Understanding language recovery in PWAs is a key area in aphasia research. Thus, the current study aimed to understand the pattern of language recovery in the acute and sub-acute stages of persons with aphasia (PWAs). A total of 11 PWAs aged between 40 and 80 were recruited. The study was conducted in two phases. In the acute stage (within one week post-stroke), participants were assessed using the Western Aphasia Battery-Kannada (WAB-K). In the sub-acute stage (between seven and fifteen days post-stroke), a similar test battery was repeated. The findings of the study showed auditory verbal comprehension scores were pronounced in the acute and sub-acute stages of recovery. Further, language quotient (LQ) scores were higher in the sub-acute stage compared to the acute stage, though these differences failed to evince statistical differences. Correlation analysis revealed strong positive correlations between LQ and spontaneous speech, repetition, and naming, with moderate correlations for auditory verbal comprehension. The study’s findings highlight the importance of targeted therapeutic interventions for PWAs, emphasizing an early focus on auditory verbal comprehension to enhance overall language recovery.

Background/Objectives: Auditory sentence comprehension often remains impaired in individuals with post-stroke aphasia despite recovery in word-level comprehension. Neuroimaging studies have identified a left perisylvian network, especially temporal regions, as central to sentence comprehension, while the role of left frontal areas and specific white matter tracts remains debated. This study uses advanced fixel-based analysis (FBA) of diffusion MRI to precisely map white matter alterations related to complex sentence comprehension deficits in subacute Mandarin-speaking aphasic patients, addressing gaps from prior voxel-based and English-specific research. Methods: Twenty-three right-handed native Mandarin speakers with subacute (1–6 months post-onset) single left-hemisphere strokes underwent diffusion MRI. Standard preprocessing and FBA were conducted. Whole-brain linear regression assessed associations between fiber density and cross-section (FDC) and non-canonical sentence comprehension, controlling for age, education, time post-stroke, and verb comprehension. Mean FDC was calculated for each tract containing at least one significant fixel identified by FBA. Partial Spearman’s correlations examined relationships between mean FDC values within these tracts and comprehension accuracy for each sentence type, controlling for the same covariates. Results: Canonical sentences were comprehended significantly better than non-canonical sentences. FBA identified significant positive correlations between FDC and non-canonical sentence comprehension in the left superior longitudinal fasciculus (SLF II and SLF III), arcuate fasciculus (AF), middle longitudinal fasciculus, inferior fronto-occipital fasciculus, and the isthmus and splenium of the corpus callosum. Fiber density reduction primarily drove reductions in FDC, whereas reductions in fiber cross-section were limited to dorsal tracts (SLF III and AF). Conclusions: This study highlights a distributed left perisylvian white matter network critical for complex sentence comprehension in Mandarin speakers, refining neurocognitive models by identifying specific white matter substrates and demonstrating FBA’s utility in aphasia research.

Stroke is a leading cause of disability and one of the primary causes of death worldwide. Stroke survivors often experience a range of symptoms, including impaired motor function, speech and language abnormalities, swallowing difficulties, cognitive deficits, visual disturbances, and sensory impairments. This meta-analysis was conducted to assess and compare the relative effectiveness of telerehabilitation compared to traditional in-person speech and language therapy for individuals with aphasia. A comprehensive literature search was conducted up to October 2024, reviewing 1,185 identified studies. Ultimately, 6 studies were selected that included a total of 168 participants with aphasia at baseline. The meta-analysis examined the relative effectiveness of telerehabilitation compared to traditional in-person speech and language therapy using continuous outcomes, with mean differences (MD) and 95% confidence intervals (95% CIs) calculated. Analyses were performed using either fixed-effect or random-effects models, depending on heterogeneity. In individuals with aphasia, telerehabilitation demonstrated significantly greater improvements in generalization post-intervention compared to face-to-face treatment (MD = 11.53; 95% CI: 3.64-19.43; p = 0.004). However, no significant differences were found between telerehabilitation and face-to-face treatment in naming accuracy post-intervention (MD = 3.09; 95% CI: 1.98-8.16; p = 0.23), Western Aphasia Battery (WAB) aphasia quotient (MD = -0.54; 95% CI: -9.96-8.88; p = 0.91), auditory comprehension post-intervention (MD = 0.66; 95% CI: -8.83-10.14; p = 0.89), or functional communication post-intervention (MD = -0.95; 95% CI: -10.19-8.29; p = 0.84). In individuals with aphasia, telerehabilitation showed significantly greater improvements in generalization post-intervention compared to face-to-face treatment. However, no significant differences were observed between the 2 approaches in naming accuracy, WAB aphasia quotient, auditory comprehension, or functional communication post-intervention. To validate these findings, further research is needed, and caution should be exercised when interpreting the current results due to the limited number of included studies.

Background: Transcranial direct current stimulation (tDCS) has emerged as a promising neuromodulatory tool for language rehabilitation in chronic aphasia. However, the effects of bi-hemispheric, multisite stimulation remain largely unexplored, especially in people with chronic and treatment-resistant language impairments. The goal of this study is to look at the effects on behavior and brain activity of an individualized language training program that combines bi-hemispheric multisite anodal tDCS with personalized language training for Albert, a patient with long-standing, treatment-resistant non-fluent aphasia. Methods: Albert, a right-handed retired physician, had transcortical motor aphasia (TCMA) subsequent to a left-hemispheric ischemic stroke occurring more than six years before the operation. Even after years of traditional treatment, his expressive and receptive language deficits remained severe and persistent despite multiple rounds of traditional therapy. He had 15 sessions of bi-hemispheric multisite anodal tDCS aimed at bilateral dorsal language streams, administered simultaneously with language training customized to address his particular phonological and syntactic deficiencies. Psycholinguistic evaluations were performed at baseline, immediately following the intervention, and at 1, 2, 3, and 6 months post-intervention. Resting-state fMRI was conducted at baseline and following the intervention to evaluate alterations in functional connectivity (FC). Results: We noted statistically significant enhancements in auditory sentence comprehension and oral reading, particularly at the 1- and 3-month follow-ups. Neuroimaging showed decreased functional connectivity (FC) in the left inferior frontal and precentral regions (dorsal stream) and in maladaptive right superior temporal regions, alongside increased FC in left superior temporal areas (ventral stream). This pattern suggests that language networks may be reorganizing in a more efficient way. There was no significant improvement in phonological processing, which may indicate reduced connectivity in the left inferior frontal areas. Conclusions: This case underscores the potential of combining individualized, network-targeted language training with bi-hemispheric multisite tDCS to enhance recovery in chronic, treatment-resistant aphasia. The convergence of behavioral gains and neuroplasticity highlights the importance of precision neuromodulation approaches. However, findings are preliminary and warrant further validation through controlled studies to establish broader efficacy and sustainability of outcomes.

This study investigated the effectiveness of the "Simon Says" game in improving students' listening skills, specifically focusing on their auditory comprehension abilities. Employing a pre-experimental design with pretest and posttest, the research involved first-year students at SMP Negeri 1 Tirawuta. Data were collected using listening tests administered before and after implementing the "Simon Says" game as a teaching intervention over eight meetings. The results demonstrated a significant improvement in students' listening skills. The mean score increased from 6.43 to 7.93 for comprehension of spoken statements and from 3.8 to 6.5 for comprehension of dialogues. Statistical analysis using a t-test confirmed the significance of these improvements (t-test values of 5.884 and 6.825 for spoken statements and dialogues, respectively, both exceeding the t-tabel value of 2.045 at df=29 and p&lt;0.05). These findings indicated that the "Simon Says" game is an effective gamification strategy for enhancing students' auditory skills in English language learning, making the learning process more engaging and less stressful. It is recommended that English teachers incorporate this game into their listening lessons.

The pre-supplementary motor area (preSMA) is a critical region within domain-general networks involved in speech production. However, the impact of post-stroke aphasia (PSA) on functional reorganization in this area remains unclear. This study aimed to investigate alterations in functional connectivity (FC) of the preSMA in patients with PSA and their relationships with neurotransmitters and speech production recovery. We conducted language assessments using the Western Aphasia Battery (WAB) on 31 patients with left hemisphere strokes at approximately 28 days and 3 months post-stroke. Functional magnetic resonance imaging (fMRI) was performed on all PSA patients and 22 normal controls (NCs) at baseline. We compared the FC of the bilateral preSMA between the two groups. Compared to NCs, PSA patients exhibited decreased FC between the ipsilesional preSMA and the prefrontal-cingulate cortex, insula, and caudate, as well as between the contralesional preSMA and the prefrontal cortex and caudate. These FC changes were significantly associated with various neurotransmitters, particularly metabotropic glutamate, kappa opioid receptor, and cannabinoid receptor. Moreover, FC between the preSMA and the prefrontal-cingulate cortex showed negative correlation trends with changes in WAB-AQ and WAB subtests (naming, auditory comprehension, and repetition) at the three-month assessment. These findings were partially validated in an independent dataset (patients: N = 17; controls: N = 22). Our results suggest that functional connections of the preSMA are disrupted in PSA patients, which may be associated with neurotransmitter activity.

Aphasia is a language network disorder caused by organic brain lesions, which severely affects patients' daily communication and interaction. The therapeutic effect of conventional rehabilitation training alone is limited. Currently, Theta Burst Stimulation (TBS) is a novel therapeutic modality of repetitive Transcranial Magnetic Stimulation (rTMS) and is a commonly used patterned rTMS. It appears in the form of burst waves and mimics the natural firing pattern of hippocampal neurons under Theta rhythm. Based on rTMS, TBS embeds a pattern in which three 50 Hz pulse bursts are inserted into a 5 Hz pulse train. This stimulation pattern can induce cortical plasticity in a shorter period of time and is gradually being applied in the treatment of aphasia. Auditory comprehension, as the initial component of language input, involves the reception and storage of linguistic signals, as well as the analysis and integration of lexical semantics. The recovery of this ability plays a prerequisite role in the functional improvement of patients with post-stroke aphasia (PSA). In recent years, research on aphasia has mainly focused on speaking, reading, and writing abilities, with relatively less attention paid to auditory comprehension. Therefore, this article reviews the research progress related to the use of TBS in treating auditory comprehension in aphasia, aiming to provide new ideas and references for the clinical selection of TBS stimulation protocols.

Universal screening for developmental language delay (DLD) is of vital importance, as early identification and intervention can significantly reduce the risk of long-term adverse outcomes, including diminished cognitive functioning, impaired communication skills, and literacy difficulties. This study aimed to determine the prevalence and risk factors associated with DLD in children. Using a community-based approach, a cross-sectional survey was conducted among residents of the Aseer region in Saudi Arabia. The study population included children aged ≤6 years. Face-to-face interviews were carried out in community settings, including nurseries and schools, where children were screened using the Arabic-translated version of the Preschool Language Scale, Fourth Edition. A total of 410 children were included; their median (interquartile range) age was 46.0 (22.0–65.0) months, 53.2% were females, 82.7% resided in urban areas, 38.5% of the studied parents reported a consanguineous relationship, and 8.5% of families reported a history of speech or language disorders. For auditory comprehension, infants exhibited the highest mean score, while kindergarten-aged children recorded the lowest mean score (105.1 ± 23.6 vs 80.7 ± 24.0; P < .001). Regarding expressive communication, infants had the highest performance, while preschoolers aged 37 to 48 months had the lowest score (101.2 ± 22.0 vs 79.4 ± 20.8; P < .001). Infants had the highest total score, while preschoolers had the lowest (113.7 ± 27.3 vs 80.9 ± 23.8; P < .001). The overall prevalence of DLD was 35.9% among all the studied children. Maternal education levels revealed a significant association, with a higher percentage of mothers in the DLD group having lower education levels compared with the non-DLD group (P = .035). A significant difference was related to the child’s nutrition, as 25.3% of children in the DLD group were breastfed compared with 45.4% who were bottle-fed (P = .001). DLD affects nearly one-third of the studied sample in the Aseer region, Saudi Arabia, and it was linked to maternal education and feeding practices. Implementaion of ommunity-based screening and intervention programs are necessary to reduce the burden of DLD.

Subcortical aphasia, caused by lesions in deep brain structures such as the basal ganglia, thalamus, and periventricular white matter, remains poorly understood due to its heterogeneous clinical presentations and disputed neural mechanisms. Unlike classical cortical aphasia syndromes, subcortical aphasia often involves subtle deficits in lexical, semantic, and phonological processing, which may be underestimated by standard assessments. This study aimed to comprehensively characterize the language profiles of patients with subcortical aphasia using a multidimensional assessment approach, and to explore the underlying components of language impairment and their relationship to aphasia severity. Thirty-four right-handed, native Chinese-speaking patients with first-ever, MRI-confirmed subcortical stroke and aphasia were enrolled within 4 weeks post-stroke. Standardized assessments included the Chinese version of the Western Aphasia Battery (WAB), the Aphasia Severity Rating Scale (ASRS), the Chinese Aphasia Fluency Characteristic Scale, and the naming battery of Chinese Aphasia Language Battery (CALB-nb). Principal component analysis (PCA) and correlation analyses were used to identify key dimensions of language impairment, with correlation coefficients calculated to quantify patient performance across linguistic domains. A one-year follow-up assessment was conducted using the ASRS to evaluate prognostic outcomes of the enrolled patients. Most patients exhibited mild to moderate aphasia, with anomic aphasia being the most prevalent subtype (47.1%). CALB naming battery results revealed high accuracy in tone decoding but lower performance in low-frequency word performance and semantic association. Strong correlations were found between phonological output and both auditory perception and phonemic decoding, as well as between auditory lexical comprehension and multiple semantic tasks. PCA identified two components-lexical-semantic and phonological-auditory, which together explained 77.3% of the variance. A composite PCA score significantly predicted aphasia severity (R 2 = 0.31, p < 0.001). At one-year follow-up, 73.6% of patients achieved functional language recovery (ASRS 4-5), and five patients resumed their pre-stroke occupations. Multidimensional assessments reveal distinct but interrelated components of lexical-semantic and phonological processing, which are closely linked to functional recovery. These findings underscore the necessity for sensitive and domain-specific language evaluations to inform prognosis and guide individualized rehabilitation strategies for subcortical aphasia.

Abstract Aim: This study evaluated the clinical utility of the Scales of Cognitive and Communicative Ability for Neurorehabilitation (SCCAN) upon assessing Bulgarian in-patients who present with either ischemic stroke or Alzheimer's disease (AD). The aim was to determine whether this tool could detect cognitive-communicative problems that may be missed by customary screening tools. Methods: We conducted two independent pilot studies: one with 14 AD patients, and a second with 19 stroke patients and 31 healthy controls. All participants completed the Bulgarian SCCAN, which assesses eight domains including oral expression, orientation, memory, auditory and reading comprehension, writing, attention, and problem-solving. Stroke and control participants also underwent the Mini-Mental State Examination (MMSE). Descriptive statistics were used so group performance and correlations could be examined. Tests that are non-parametric were also used. Results: SCCAN revealed domain-specific deficits in clinical cohorts. In the AD group, memory and orientation were the most impaired domains. Stroke patients, on the other hand, showed significant impairments, particularly in memory, oral expression, and auditory comprehension, while orientation and attention were relatively preserved. Overall, stroke patients performed significantly better on the SCCAN than the AD group. These findings reveal distinct cognitive–communicative profiles in AD versus stroke populations. Conclusion: SCCAN's Bulgarian version identified cognitive-communicative deficits with clinical sensitivity in patients with AD as well as with those with ischemic stroke. The tool may guide individualized neurorehabilitation and complement standard screening methods. Additional verification is advised.

Objective Limited studies have examined the prevalence of hearing loss among Syrian refugees living in Turkey, where it is anticipated to be higher compared to the general population. 430,148 Syrian refugees live in Gaziantep province, where this study was conducted. This study aimed to examine the auditory perception, word and sentence comprehension, and speech recognition outcomes of Syrian refugee children who underwent cochlear implantation (CI). Design Among 960 individuals who underwent CI surgery between August 2015 and April 2023, 135 (14.6%) were Syrian refugee children. The Arabic version of the Evaluation of Auditory Responses to Speech (EARS) test battery was used to assess language development and auditory perception levels of the Syrian refugees. Studysample Data on auditory perception and speech recognition from 30 Syrian refugee children with CI were analyzed. Results CI was performed in Syrian refugee children at an average age of 39.57 ± 17.56 months. Findings of the study showed that the socioeconomic conditions of the Syrian refugee group were quite limited, with 93.33% of participants not receiving regular special education. It was observed that the age of access to CI was delayed for Syrian refugee children. EARS test scores for Syrian refugee CI users were significantly lower than normative values (p < 0.05). Conclusion Despite using CIs, many Syrian refugee children demonstrated lower-than-expected performance in auditory and language development, likely owing to socioeconomic disadvantages, lack of access to special education, and delayed implantation. These findings highlight the need for early diagnosis, timely implantation, and effective rehabilitation programs for refugee children.

The objective of the present study was to investigate the linguistic profile of patients with multiple sclerosis and to establish a connection between the corresponding linguistic deficits and specific brain regions. Specifically, for the purposes of this research, 12 adults diagnosed with secondary progressive multiple sclerosis were examined and compared with healthy participants. The Boston Aphasia Naming Test, a standardized linguistic tool, was administered, focusing on the subtests for auditory comprehension, repetition, and reading comprehension. The results demonstrated that the group of participants with multiple sclerosis exhibited significantly lower performance in the comprehension subtest compared to the control group. The findings are discussed.

ABSTRACT The debate remains unresolved regarding whether identical language control mechanisms underlie production and comprehension in individuals who use two or more languages. Most previous research focused solely on switching costs aggregated at the group level, potentially overlooking a broader set of indices and individual variabilities. To address this, we integrated the n-2 repetition paradigm, language-switching paradigm, and single-language tasks to examine two modalities in Cantonese–Mandarin–English trilinguals: spoken word production (Experiment 1) and auditory word comprehension (Experiment 2). We evaluated a wider range of language control indices, including n-2 repetition, switching, and mixing costs. Group-level analyses revealed significant effects for all indices in production, whereas only mixing costs reached significance in comprehension. Individual differences analyses showed no significant correlations between production and comprehension across three types of costs, with Bayesian statistics providing supporting evidence for the absence of such relationships in most cases. Radar and permutation analyses further showed that language control in production was quantitatively greater than comprehension, and qualitatively distinct in pattern from comprehension. These findings show that language control in production is not only stronger, but also qualitatively distinct from that in comprehension, underscoring the importance of distinguishing between modalities in models of language control.

Lesion-symptom mapping techniques are essential to determine brain regions critical for language functions. However, high collinearity in neuroimaging and behavioural data remains a challenge for distinguishing neural substrates supporting multiple language domains (shared variance) and those subserving specific language functions (unique variance). Here, we employed a novel approach to multimodal lesion-symptom mapping using multivariate partial least squares regression to delineate the latent structure of lesion-behavioural mapping in aphasia and decompose the shared and unique neural determinants of language impairments. A total of 86 participants with chronic (>12-month post-stroke) aphasia after left hemisphere strokes were examined. Language impairment was assessed with the Western Aphasia Battery-Revised, and brain damage was defined by multimodal neuroimaging (including lesion characteristics, structural and functional connectivity, volumetric measures and functional activity). Neuroimaging modality-specific models were constructed to evaluate the shared versus unique lesion anatomy associated with performance across Western Aphasia Battery-Revised subtests: auditory comprehension, naming, repetition and spontaneous speech. Model accuracy was validated using leave-one-out cross-validation. Latent decomposition revealed that 50% of the covariance between neuroimaging data and language performance was explained by two to six latent variables across models. The spontaneous speech subtest emerged as the most influential language measure across all models, with damage to regions surrounding the perisylvian fissure accounting for the largest amount of shared variance across Western Aphasia Battery-Revised subtests. Critically, the highest-ranking features represented in the latent variable models yielded moderately accurate simultaneous prediction for all language measures (highest r: auditory comprehension = 0.45; naming = 0.39; repetition = 0.38; spontaneous speech = 0.42), suggesting that clinically salient language impairments largely reflect damage to shared anatomical networks. Projection of subtest scores onto latent variables revealed that integrity of distributed left and right cortical and subcortical regions uniquely accounted for 5.0–27.9% of residual variance across subtests, with auditory comprehension involving the most extensive network of unique brain regions. These results highlight that dissociating shared versus unique lesion-symptom associations is important for understanding the neural basis of aphasia. Shared lesion anatomy involving perisylvian regions broadly impacts multiple language domains, while distributed regions uniquely explain deficits in specific language domains (e.g. auditory comprehension). These insights improve our understanding of post-stroke aphasia and facilitate future development of more precise, personalized treatment strategies based on each individual’s neuroanatomy.

Most studies documenting the longitudinal recovery of auditory comprehension in poststroke aphasia begin in the subacute phase. The present study aimed to address this gap by exploring the longitudinal changes in auditory comprehension from the acute to the chronic phase and their neural correlates. Twenty-one Laurentian French persons with aphasia (PWA) following a first left middle cerebral artery stroke underwent three language assessments (acute: 0-72 hr, subacute: 7-14 days, chronic: 6-12 months postonset). Auditory comprehension was assessed at each time point using two tasks, sentence-picture matching and sequential commands. From the sentence-picture matching task, four measures were extracted (single-word, subject-verb, canonical subject-verb-object, and noncanonical subject-verb-object comprehension), while one measure was derived from the sequential commands task, totaling five measures. Lesion-symptom mapping (LSM) was used to identify the brain regions associated with comprehension impairments. All five auditory comprehension measures showed significant positive changes between acute and chronic phases. Persistent comprehension impairments with canonical sentences and sequential commands were more likely to occur in the chronic phase. LSM analyses revealed that comprehension of noncanonical sentences was associated with lesions in the supramarginal gyrus and extended to the superior temporal gyrus (STG) and middle temporal gyrus (MTG). Similarly, the comprehension of sequential commands was associated with lesions in the MTG, extending to the STG and insula. The current findings suggest that PWA with more severe impairments in the acute phase reach a similar performance in the chronic phase than people with milder aphasia and suggest a critical role for the left MTG in the recovery of auditory comprehension, especially with complex stimuli. https://doi.org/10.23641/asha.29202788.