Processing Deficits Research Articles

Low gain hearing aids use and benefit: A viable management option for those with hearing sensitivity within the normal range

Low (or mild) gain hearing aids (LGHAs) are increasingly considered for individuals with normal peripheral hearing but self-reported auditory complaints. The Tinnitus and Hearing Survey-Hearing Subscale (THS-H) offers a normative cutoff, aiding identification of significant self-reported hearing difficulties (SHD). This research assesses the benefits of LGHAs as a management option for individuals with normal hearing sensitivity and significant SHD, comparing LGHA use and benefit to individuals without SHD and those with peripheral hearing loss. 186 participants across four groups, including those with or without SHD and peripheral hearing loss were recruited. Participants completed questionnaires that addressed hearing aid usage, benefit, SHD and tinnitus. Individuals with significant SHD and hearing sensitivity within the normal range (NHT) reported higher LGHA usage and benefit than individuals with normal hearing difficulties (NHD) and NHT. Comparable use and benefit were noted between groups with significant SHD regardless of peripheral hearing loss status. The findings support LGHAs as a suitable management option for individuals with NHT and SHD, as indicated by hearing aid use and benefit. Quantifying the level of perceived auditory processing deficits (i.e., SHD), notably with the THS-H, enhances sensitivity in identifying those who may benefit from this management option.

Visual processing speed and its association with future dementia development in a population-based prospective cohort: EPIC-Norfolk

Visual processing deficits have frequently been reported when studied in individuals with dementia, which suggests their potential utility in supporting dementia screening. The study uses EPIC-Norfolk Prospective Population Cohort Study data (n = 8623) to investigate the role of visual processing speed assessed by the Visual Sensitivity Test (VST) in identifying the risk of future dementia using Cox regression analyses. Individuals with lower scores on the simple and complex VST had a higher probability of a future dementia diagnosis HR1.39 (95% CI 1.12, 1.67, P < 0.01) and HR 1.56 (95% CI 1.27, 1.90, P < 0.01), respectively. Although other more commonly used cognitive dementia screening tests were better predictors of future dementia risk (HR 3.45 for HVLT and HR 2.66, for SF-EMSE), the complex VST showed greater sensitivity to variables frequently associated with dementia risk. Reduced complex visual processing speed is significantly associated with a high likelihood of a future dementia diagnosis and risk/protective factors in this cohort. Combining visual processing tests with other neuropsychological tests could improve the identification of future dementia risk.

Focal Brain Lesions Causing Acquired Amusia Map to a Common Brain Network.

Music is a universal human attribute. The study of amusia, a neurologic music processing deficit, has increasingly elaborated our view on the neural organization of the musical brain. However, lesions causing amusia occur in multiple brain locations and often also cause aphasia, leaving the distinct neural networks for amusia unclear. Here, we utilized lesion network mapping to identify these networks. A systematic literature search was carried out to identify all published case reports of lesion-induced amusia. The reproducibility and specificity of the identified amusia network were then tested in an independent prospective cohort of 97 stroke patients (46 female and 51 male) with repeated structural brain imaging, specifically assessed for both music perception and language abilities. Lesion locations in the case reports were heterogeneous but connected to common brain regions, including bilateral temporoparietal and insular cortices, precentral gyrus, and cingulum. In the prospective cohort, lesions causing amusia mapped to a common brain network, centering on the right superior temporal cortex and clearly distinct from the network causally associated with aphasia. Lesion-induced longitudinal structural effects in the amusia circuit were confirmed as reduction of both gray and white matter volume, which correlated with the severity of amusia. We demonstrate that despite the heterogeneity of lesion locations disrupting music processing, there is a common brain network that is distinct from the language network. These results provide evidence for the distinct neural substrate of music processing, differentiating music-related functions from language, providing a testable target for noninvasive brain stimulation to treat amusia.

Aberrant dynamic functional connectivity of thalamocortical circuitry in major depressive disorder.

Thalamocortical circuitry has a substantial impact on emotion and cognition. Previous studies have demonstrated alterations in thalamocortical functional connectivity (FC), characterized by region-dependent hypo- or hyper-connectivity, among individuals with major depressive disorder (MDD). However, the dynamical reconfiguration of the thalamocortical system over time and potential abnormalities in dynamic thalamocortical connectivity associated with MDD remain unclear. Hence, we analyzed dynamic FC (dFC) between ten thalamic subregions and seven cortical subnetworks from resting-state functional magnetic resonance images of 48 patients with MDD and 57 healthy controls (HCs) to investigate time-varying changes in thalamocortical FC in patients with MDD. Moreover, dynamic laterality analysis was conducted to examine the changes in functional lateralization of the thalamocortical system over time. Correlations between the dynamic measures of thalamocortical FC and clinical assessment were also calculated. We identified four dynamic states of thalamocortical circuitry wherein patients with MDD exhibited decreased fractional time and reduced transitions within a negative connectivity state that showed strong correlations with primary cortical networks, compared with the HCs. In addition, MDD patients also exhibited increased fluctuations in functional laterality in the thalamocortical system across the scan duration. The thalamo-subnetwork analysis unveiled abnormal dFC variability involving higher-order cortical networks in the MDD cohort. Significant correlations were found between increased dFC variability with dorsal attention and default mode networks and the severity of symptoms. Our study comprehensively investigated the pattern of alteration of the thalamocortical dFC in MDD patients. The heterogeneous alterations of dFC between the thalamus and both primary and higher-order cortical networks may help characterize the deficits of sensory and cognitive processing in MDD.

Age-Related Deficits in Binaural Hearing: Contribution of Peripheral and Central Effects.

Pure-tone audiograms often poorly predict elderly humans' ability to communicate in everyday complex acoustic scenes. Binaural processing is crucial for discriminating sound sources in such complex acoustic scenes. The compromised perception of communication signals presented above hearing threshold has been linked to both peripheral and central age-related changes in the auditory system. Investigating young and old Mongolian gerbils of both sexes, an established model for human hearing, we demonstrate age-related supra-threshold deficits in binaural hearing using behavioral, electrophysiological, anatomical, and imaging methods. Binaural processing ability was measured as the binaural masking level difference (BMLD), an established measure in human psychophysics. We tested gerbils behaviorally with "virtual headphones," recorded single-unit responses in the auditory midbrain and evaluated gross midbrain and cortical responses using positron emission tomography (PET) imaging. Furthermore, we obtained additional measures of auditory function based on auditory brainstem responses, auditory-nerve synapse counts, and evidence for central inhibitory processing revealed by PET. BMLD deteriorates already in middle-aged animals having normal audiometric thresholds and is even worse in old animals with hearing loss. The magnitude of auditory brainstem response measures related to auditory-nerve function and binaural processing in the auditory brainstem also deteriorate. Furthermore, central GABAergic inhibition is affected by age. Because the number of synapses in the apical turn of the inner ear was not reduced in middle-aged animals, we conclude that peripheral synaptopathy contributes little to binaural processing deficits. Exploratory analyses suggest increased hearing thresholds, altered binaural processing in the brainstem and changed central GABAergic inhibition as potential contributors.

White matter network underlying semantic processing: evidence from stroke patients.

The hub-and-spoke theory of semantic representation fractionates the neural underpinning of semantic knowledge into two essential components: the sensorimotor modality-specific regions and a crucially important semantic hub region. Our previous study in patients with semantic dementia has found that the hub region is located in the left fusiform gyrus. However, because this region is located within the brain damage in patients with semantic dementia, it is not clear whether the semantic deficit is caused by structural damage to the hub region itself or by its disconnection from other brain regions. Stroke patients do not have any damage to the left fusiform gyrus, but exhibit amodal and modality-specific deficits in semantic processing. Therefore, in this study, we validated the semantic hub region from a brain network perspective in 79 stroke patients and explored the white matter connections associated with it. First, we collected data of diffusion-weighted imaging and behavioural performance on general semantic tasks and modality-specific semantic tasks (assessing object knowledge on form, colour, motion, sound, manipulation and function). We then used correlation and regression analyses to examine the association between the nodal degree values of brain regions in the whole-brain structural network and general semantic performance in the stroke patients. The results revealed that the connectivity of the left fusiform gyrus significantly predicted general semantic performance, indicating that this region is the semantic hub. To identify the semantic-relevant connections of the semantic hub, we then correlated the white matter integrity values of each tract connected to the left fusiform gyrus separately with performance on general and modality-specific semantic processing. We found that the hub region accomplished general semantic processing through white matter connections with the left superior temporal pole, middle temporal gyrus, inferior temporal gyrus and hippocampus. The connectivity between the hub region and the left hippocampus, superior temporal pole, middle temporal gyrus, inferior temporal gyrus and parahippocampal gyrus was differentially involved in object form, colour, motion, sound, manipulation and function processing. After statistically removing the effects of potential confounding variables (i.e. whole-brain lesion volume, lesion volume of regions of interest and performance on non-semantic control tasks), the observed effects remained significant. Together, our findings support the role of the left fusiform gyrus as a semantic hub region in stroke patients and reveal its crucial connectivity in the network. This study provides new insights and evidence for the neuroanatomical organization of semantic memory in the human brain.

The Gaze of Schizophrenia Patients Captured by Bottom-up Saliency

Schizophrenia (SCHZ) notably impacts various human perceptual modalities, including vision. Prior research has identified marked abnormalities in perceptual organization in SCHZ, predominantly attributed to deficits in bottom-up processing. Our study introduces a novel paradigm to differentiate the roles of top-down and bottom-up processes in visual perception in SCHZ. We analysed eye-tracking fixation ground truth maps from 28 SCHZ patients and 25 healthy controls (HC), comparing these with two mathematical models of visual saliency: one bottom-up, based on the physical attributes of images, and the other top-down, incorporating machine learning. While the bottom-up (GBVS) model revealed no significant overall differences between groups (beta = 0.01, p = 0.281, with a marginal increase in SCHZ patients), it did show enhanced performance by SCHZ patients with highly salient images. Conversely, the top-down (EML-Net) model indicated no general group difference (beta = −0.03, p = 0.206, lower in SCHZ patients) but highlighted significantly reduced performance in SCHZ patients for images depicting social interactions (beta = −0.06, p < 0.001). Over time, the disparity between the groups diminished for both models. The previously reported bottom-up bias in SCHZ patients was apparent only during the initial stages of visual exploration and corresponded with progressively shorter fixation durations in this group. Our research proposes an innovative approach to understanding early visual information processing in SCHZ patients, shedding light on the interplay between bottom-up perception and top-down cognition.

Asymmetry in Cortical Thickness of the Heschl's Gyrus in Unilateral Ear Canal Atresia.

Unilateral congenital conductive hearing impairment in ear canal atresia leads to atrophy of the gray matter of the contralateral primary auditory cortex or changes in asymmetry pattern if left untreated in childhood. Unilateral ear canal atresia with associated severe conductive hearing loss results in deteriorated sound localization and difficulties in understanding of speech in a noisy environment. Cortical atrophy in the Heschl's gyrus has been reported in acquired sensorineural hearing loss but has not been studied in unilateral conductive hearing loss. We obtained T1w and T2w FLAIR MRI data from 17 subjects with unilateral congenital ear canal atresia and 17 matched controls. Gray matter volume and thickness were measured in the Heschl's gyrus using Freesurfer. In unilateral congenital ear canal atresia, Heschl's gyrus exhibited cortical thickness asymmetry (right thicker than left, corrected p = 0.0012, mean difference 0.25 mm), while controls had symmetric findings. Gray matter volume and total thickness did not differ from controls with normal hearing. We observed cortical thickness asymmetry in congenital unilateral ear canal atresia but no evidence of contralateral cortex atrophy. Further research is needed to understand the implications of this asymmetry on central auditory processing deficits.

Profiles of mathematical deficits in children with dyslexia

Despite a high rate of concurrent mathematical difficulties among children with dyslexia, we still have limited information regarding the prevalence and severity of mathematical deficits in this population. To address this gap, we developed a comprehensive battery of cognitive tests, known as the UCSF Mathematical Cognition Battery (MCB), with the aim of identifying deficits in four distinct mathematical domains: number processing, arithmetical procedures, arithmetic facts retrieval, and geometrical abilities. The mathematical abilities of a cohort of 75 children referred to the UCSF Dyslexia Center with a diagnosis of dyslexia, along with 18 typically developing controls aged 7 to 16, were initially evaluated using a behavioral neurology approach. A team of professional clinicians classified the 75 children with dyslexia into five groups, based on parents’ and teachers’ reported symptoms and clinical history. These groups included children with no mathematical deficits and children with mathematical deficits in number processing, arithmetical procedures, arithmetic facts retrieval, or geometrical abilities. Subsequently, the children underwent evaluation using the MCB to determine concordance with the clinicians’ impressions. Additionally, neuropsychological and cognitive standardized tests were administered. Our study reveals that within a cohort of children with dyslexia, 66% exhibit mathematical deficits, and among those with mathematical deficits, there is heterogeneity in the nature of these deficits. If these findings are confirmed in larger samples, they can potentially pave the way for new diagnostic approaches, consistent subtype classification, and, ultimately personalized interventions.

Enabling brief assessments of alexithymia: psychometric properties of the Russian version of the Perth Alexithymia Questionnaire-Short Form (PAQ-S) and its correlates with ill-being and well-being

Alexithymia is a trait involving deficits in emotion processing. As an important risk factor for a wide range of psychopathologies, its assessment is important in both research and clinical practice. Originally developed in English, the Perth Alexithymia Questionnaire-Short Form (PAQ-S) is a 6-item self-report measure of alexithymia, with its brevity designed to enable alexithymia assessments in a wide range of settings. In the present research, we aimed to introduce the first Russian version of the PAQ-S and examine its psychometric properties. Our sample consisted of 203 Russian-speaking adults aged 18–74 years, recruited from the general community in Russia. The PAQ-S’s factor structure was verified with confirmatory factor analysis. Convergent and divergent validity was assessed via relationships with psychopathology symptoms and well-being. Internal consistency reliability was evaluated. The Russian version of the PAQ-S demonstrated strong factorial validity, with support for the intended 1-factor structure as an overall marker of alexithymia. The PAQ-S total scale score showed good internal consistency reliability. As expected, its convergent and divergent validity was also supported. PAQ-S scores were significant predictors of higher ill-being (anxiety, depression, and stress) and lower well-being, thus demonstrating the high clinical relevance of the alexithymia construct as measured by the PAQ-S. There were no gender differences in PAQ-S scores, and alexithymia was higher in younger people and those with less education. Overall, the Russian PAQ-S therefore demonstrated strong psychometric properties as a brief and robust measure of overall alexithymia, performing similarly to other language versions.

Design and methodology for a proof of mechanism study of individualized neuronavigated continuous Theta burst stimulation for auditory processing in adolescents with autism spectrum disorder.

It has been suggested that aberrant excitation/inhibition (E/I) balance and dysfunctional structure and function of relevant brain networks may underlie the symptoms of autism spectrum disorder (ASD). However, the nomological network linking these constructs to quantifiable measures and mechanistically relating these constructs to behavioral symptoms of ASD is lacking. Herein we describe a within-subject, controlled, proof-of-mechanism study investigating the pathophysiology of auditory/language processing in adolescents with ASD. We utilize neurophysiological and neuroimaging techniques including magnetic resonance spectroscopy (MRS), diffusion-weighted imaging (DWI), functional magnetic resonance imaging (fMRI), and magnetoencephalography (MEG) metrics of language network structure and function. Additionally, we apply a single, individually targeted session of continuous theta burst stimulation (cTBS) as an experimental probe of the impact of perturbation of the system on these neurophysiological and neuroimaging outcomes. MRS, fMRI, and MEG measures are evaluated at baseline and immediately prior to and following cTBS over the posterior superior temporal cortex (pSTC), a region involved in auditory and language processing deficits in ASD. Also, behavioral measures of ASD and language processing and DWI measures of auditory/language network structures are obtained at baseline to characterize the relationship between the neuroimaging and neurophysiological measures and baseline symptom presentation. We hypothesize that local gamma-aminobutyric acid (GABA) and glutamate concentrations (measured with MRS), and structural and functional activity and network connectivity (measured with DWI and fMRI), will significantly predict MEG indices of auditory/language processing and behavioral deficits in ASD. Furthermore, a single session of cTBS over left pSTC is hypothesized to lead to significant, acute changes in local glutamate and GABA concentration, functional activity and network connectivity, and MEG indices of auditory/language processing. We have completed the pilot phase of the study (n=20 Healthy Volunteer adults) and have begun enrollment for the main phase with adolescents with ASD (n=86; age 14-17). If successful, this study will establish a nomological network linking local E/I balance measures to functional and structural connectivity within relevant brain networks, ultimately connecting them to ASD symptoms. Furthermore, this study will inform future therapeutic trials using cTBS to treat the symptoms of ASD.

Language uncovers visuospatial dysfunction in posterior cortical atrophy: a natural language processing approach.

Posterior Cortical Atrophy (PCA) is a syndrome characterized by a progressive decline in higher-order visuospatial processing, leading to symptoms such as space perception deficit, simultanagnosia, and object perception impairment. While PCA is primarily known for its impact on visuospatial abilities, recent studies have documented language abnormalities in PCA patients. This study aims to delineate the nature and origin of language impairments in PCA, hypothesizing that language deficits reflect the visuospatial processing impairments of the disease. We compared the language samples of 25 patients with PCA with age-matched cognitively normal (CN) individuals across two distinct tasks: a visually-dependent picture description and a visually-independent job description task. We extracted word frequency, word utterance latency, and spatial relational words for this comparison. We then conducted an in-depth analysis of the language used in the picture description task to identify specific linguistic indicators that reflect the visuospatial processing deficits of PCA. Patients with PCA showed significant language deficits in the visually-dependent task, characterized by higher word frequency, prolonged utterance latency, and fewer spatial relational words, but not in the visually-independent task. An in-depth analysis of the picture description task further showed that PCA patients struggled to identify certain visual elements as well as the overall theme of the picture. A predictive model based on these language features distinguished PCA patients from CN individuals with high classification accuracy. The findings indicate that language is a sensitive behavioral construct to detect visuospatial processing abnormalities of PCA. These insights offer theoretical and clinical avenues for understanding and managing PCA, underscoring language as a crucial marker for the visuospatial deficits of this atypical variant of Alzheimer's disease.

Visual search patterns during exploration of naturalistic scenes are driven by saliency cues in individuals with cerebral visual impairment

We investigated the relative influence of image salience and image semantics during the visual search of naturalistic scenes, comparing performance in individuals with cerebral visual impairment (CVI) and controls with neurotypical development. Participants searched for a prompted target presented as either an image or text cue. Success rate and reaction time were collected, and gaze behavior was recorded with an eye tracker. A receiver operating characteristic (ROC) analysis compared the distribution of individual gaze landings based on predictions of image salience (using Graph-Based Visual Saliency) and image semantics (using Global Vectors for Word Representations combined with Linguistic Analysis of Semantic Salience) models. CVI participants were less likely and were slower in finding the target. Their visual search behavior was also associated with a larger visual search area and greater number of fixations. ROC scores were also lower in CVI compared to controls for both model predictions. Furthermore, search strategies in the CVI group were not affected by cue type, although search times and accuracy showed a significant correlation with verbal IQ scores for text-cued searches. These results suggest that visual search patterns in CVI are driven mainly by image salience and provide further characterization of higher-order processing deficits observed in this population.

Remote digital cognitive assessment reveals cognitive deficits related to hippocampal atrophy in autoimmune limbic encephalitis: a cross-sectional validation study

Autoimmune limbic encephalitis (ALE) is a neurological disease characterised by inflammation of the limbic regions of the brain, mediated by pathogenic autoantibodies. Because cognitive deficits persist following acute treatment of ALE, the accurate assessment of long-term cognitive outcomes is important for clinical assessments and trials. However, evaluating cognition is costly and an unmet need exists for validated digital methods. In this cross-sectional validation study, we investigated whether a remote digital platform could identify previously characterised cognitive impairments in patients with chronic ALE and whether digital metrics would correlate with standard neuropsychological assessment and hippocampal volume. Patients with ALE who had a chronic and stable presentation and received a clinical diagnosis of ALE were recruited for this study. The cognitive performance of 21 patients with ALE and 54 age-matched healthy controls - enrolled via the University of Oxford (UK) Cognitive Neurology Lab testing programme - was assessed with a battery of 12 cognitive tasks from the Cognitron online platform. The platform was optimised with National Institute for Health and Care Research (NIHR) support to be deliverable remotely to elderly and patient groups. The primary outcome measure was behavioural performance and corresponding neuroimaging and neuropsychological assessment metrics. Between February 15, 2021, and April 21, 2022, 21 patients with ALE (mean age 63.01 years, 14 males) and 54 healthy controls (mean age 65.56 years, 23 males) completed the digital cognitive assessment. Patients with ALE performed significantly worse in memory, visuospatial abilities, executive function, and language. No impairments in digit & spatial span, target detection (attention) and emotion discrimination were observed. The global score on the online cognitive tasks correlated significantly with the established Addenbrooke's Cognitive Examination III (ACE) pen-and-paper test. Deficits in visuospatial processing and language were identified in ALE compared to controls using remote digital testing but not using the ACE, highlighting higher sensitivity of computerised testing to residual cognitive impairment. Finally, the hippocampal volumes of patients with ALE and healthy controls correlated with online cognitive scores. These findings demonstrate that subtle cognitive deficits in patients with chronic ALE, who often show full recovery in measures of disability and dependence on daily activities, are detectable using a remote online platform, which also relates to hippocampal atrophy. Such methods may facilitate the characterisation of cognitive profiles in complex neurological diseases. Future longitudinal studies designed to assess the utility of such digital methods for further clinical characterisation are needed. The Wellcome Trust, Medical Research Council, National Institute for Health Research, Rhodes Scholarship, and the Berrow Foundation Scholarship.

Childhood emotion dysregulation mediates the relationship between preschool emotion labeling and adolescent depressive symptoms.

Deficits in emotion processing (e.g., emotion labeling and regulation) are widely implicated in depression risk. While prior literature documents these deficits in concurrence with depression, more research is needed to investigate emotion processing pathways of depression risk across development. The purpose of this study was to investigate if emotion processes (i.e., emotion labeling and emotion regulation/dysregulation) in early and middle childhood predict adolescent depressive symptom severity in a prospective sample. Data were analyzed from a longitudinal study of diverse preschoolers oversampled for depressive symptoms using measures of preschool emotion labeling of faces (i.e., Facial Affect Comprehension Evaluation), middle childhood emotion regulation and dysregulation (i.e., emotion regulation checklist), and adolescent depressive symptoms (i.e., PAPA, CAPA, and KSADS-PL diagnostic interviews). Multilevel models indicated that preschoolers with depression had similar development of emotion labeling in early childhood as peers. Mediation analyses revealed that deficits in preschool-aged anger and surprise labeling ability indirectly predicted higher adolescent depressive symptom severity through increased middle childhood emotion lability/negativity, not decreased emotion regulation. Adolescent depression may be predicted by an emotion processing pathway that spans from early childhood to adolescence, and findings may generalize to high risk for depression youth samples. Specifically, poor emotion labeling in early childhood may lead to increased childhood emotion lability/negativity, which increases the risk for adolescent depressive symptom severity. Findings may help identify specific emotion processing relations in childhood that increase the risk for depression and inform intervention aimed at improving preschoolers' anger and surprise labeling. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Facilitation of sensorimotor temporal recalibration mechanisms by cerebellar tDCS in patients with schizophrenia spectrum disorders and healthy individuals

Core symptoms in patients with schizophrenia spectrum disorders (SSD), like hallucinations or ego-disturbances, have been associated with a failure of internal forward models to predict the sensory outcomes of self-generated actions. Importantly, forward model predictions must also be able to flexibly recalibrate to changing environmental conditions, for example to account for additional delays between action and outcome. We investigated whether transcranial direct current stimulation (tDCS) can be used to improve these sensorimotor temporal recalibration mechanisms in patients and healthy individuals. While receiving tDCS on the cerebellum, temporo-parietal junction, supplementary motor area, or sham stimulation, patients with SSD and healthy control participants were repeatedly exposed to delays between actively or passively elicited button presses and auditory outcomes. Effects of this procedure on temporal perception were assessed with a delay detection task. Similar recalibration outcomes and faciliatory effects of cerebellar tDCS on recalibration were observed in SSD and healthy individuals. Our findings indicate that sensorimotor recalibration mechanisms may be preserved in SSD and highlight the importance of the cerebellum in both patients and healthy individuals for this process. They further suggest that cerebellar tDCS could be a promising tool for addressing deficits in action-outcome monitoring and related adaptive sensorimotor processes in SSD.

Abstract TMP11: Cerebral Visual Impairment in Pediatric Stroke Patients Assessed by Virtual Reality Testing

Introduction: Pediatric stroke is one of the leading causes of disability in children, many of whom incur brain injury affecting critical visual anatomical networks. Dedicated ophthalmologic examinations that detect cerebral visual impairment (CVI) - the leading cause of congenital visual impairment in developed countries - are not standard of care and can delay diagnosis and interventions. There is limited CVI data in pediatric stroke patients, and in this work we present data defining visual processing deficits in pediatric stroke patients. Hypothesis: We hypothesize that pediatric stroke patients will (1) demonstrate greater visual-spatial processing impairments than controls and (2) demonstrate increasing performance impairment as a function of increasing visual task demands. Methods: Using a virtual reality (VR) based visual search task system, we characterized significant deficits in higher-order visual processing of pediatric stroke patients (n = 17) as compared to healthy controls (n = 13). Stroke patients suffered from a perinatal (n = 8) or pediatric (n = 9) stroke - confirmed with brain MRI - affecting various vascular territories of the anterior and posterior circulations. The task required searching for on-screen targets with increasing visual complexity. Metrics such as reaction time, gaze error, shifted ellipse area, success rate, and pursuit saccade ratio were analyzed using unpaired group-level t-tests and considered significant if p &lt; 0.05. Results: Stroke patients took longer to identify the target (p = 0.001), were less accurate in finding it (p = 0.007), and exhibited greater impairment in performance with an increasing number of distractors compared to healthy children. Groups had comparable task compliance, as indexed by an off-screen count metric. Conclusion: This original work demonstrates that pediatric stroke patients, particularly those with strokes affecting the middle cerebral artery and posterior circulation vascular territories, exhibit impaired higher-order visual processing. This highlights the urgent need for standardized clinical testing to provide quantitative performance measures of cortical visual processing. This will allow timely detection and implementation of interventional therapies.

Abstract WP223: Cerebral Visual Impairment in ACTA2 Patients Assessed by Virtual Reality Testing

Introduction: Heterozygous missense mutations disrupting arginine 179 (Arg179) in the ACTA2 gene which codes for the smooth muscle-specific isoform of α-actin, cause Multisystemic Smooth Muscle Dysfunction Syndrome (MSMDS). The clinical manifestations of this genetic condition include congenital mydriasis, patent ductus arteriosus, stroke, and/or aortic aneurysms or dissections among many others. White matter injury, impaired autoregulation, and neurovascular coupling (due to the cerebral vasculopathy affecting cerebral perfusion) are known factors that alter neural network performance and processing speed. The lack of a standardized ophthalmologic examination that detects cerebral visual impairment (CVI), precludes an early diagnosis and creates missed opportunities for intervention. There is a paucity of data regarding CVI in MSMDS patients, and through this novel work, we present data defining their visual processing deficits. Hypothesis: We hypothesize that: 1) individuals with MSMDS will exhibit more pronounced deficits in visual-spatial processing compared to the control group, and 2) their performance will deteriorate as the complexity of visual tasks increases. Methods: Using a virtual reality (VR) based visual search task system, we characterized the impairment of higher-order visual processing in MSMDS patients (n = 4) as compared to healthy controls (n = 13). The VR-based task required searching for targets on a screen among varying levels of visual complexity. Reaction time, gaze error, shifted ellipse area, success rate, and pursuit saccade ratio were statistically analyzed with unpaired group t-tests, with significance being defined as p &lt; 0.05. Results: Compared to controls, MSMDS patients took longer to identify the correct target, were less accurate in finding the target, and exhibited greater impairment in performance with an increasing number of distractors. Both groups showed similar task compliance, measured using an off-screen count metric. Conclusion: This novel work demonstrates that MSMDS patients exhibit impaired higher-order visual processing. This highlights the need for clinical tools that can assess these difficulties with quantitative methods to guide therapies and improve functional outcomes.

Exploring vowel errors produced in nonword repetition in children with speech and language disorders.

Accurate nonword repetition (NWR) is contingent on many underlying skills, including encoding, memory and motor planning and programming. Though vowel errors are frequently associated with childhood apraxia of speech (CAS), several recent studies have found that children with developmental language disorder (DLD) produce high rates of vowel errors in NWR tasks. This retrospective analysis explored whether the overall frequency and types of vowel errors produced in NWR distinguish children with DLD, children with CAS, children with speech sound disorder (SSD) and children with typical development (TD). We present data for 24 children (six per DLD, CAS, SSD and TD groups), ranging in age from 50-92 months. Children with DLD, CAS and SSD showed similar articulation scores and children with DLD and children with CAS showed similar expressive language scores. Total vowel errors, total monophthong errors, monophthong substitutions, diphthongization errors, total diphthong errors, diphthong substitutions and diphthong reduction errors were calculated by syllable length and group. Repeated measures analyses of variance were used to examine group differences. Children with DLD and children with CAS produced a higher frequency of total vowel errors compared to children with TD. Children with DLD produced more total monophthong errors than children with TD. Children with DLD and children with CAS produced more total diphthong errors than children with TD. For children with DLD, these were characterised by diphthong substitutions. For children with CAS, these were characterised by diphthong substitutions and diphthong reduction errors. For all measures, error rates in children with SSD did not significantly differ from any of the other three groups. Preliminary evidence indicates that children with DLD and children with CAS both show high rates of vowel errors in NWR tasks and weaknesses in encoding and memory. For children with CAS, additional motor planning difficulties are associated with an increased likelihood to reduce diphthongs. Children with SSD show more mild processing difficulties than children with DLD and children with CAS, though they do not perform as well as TD peers. Future work should replicate and further specify the processing weaknesses that affect vowel accuracy in NWR tasks in a larger sample. What is already known on the subject Nonword repetition (NWR) tasks are often included in diagnostic batteries to identify children with developmental language disorder (DLD). Poor performance on these tasks have historically been attributed to phonological working memory deficits in children with DLD. However, repeating nonwords relies on a number of underlying processing skills and many of these skills are affected to varying degrees in children with speech and language disorders. An in-depth analysis of vowel errors has the potential to reveal the shared as well as specific underlying processing weaknesses in children with DLD, children with childhood apraxia of speech (CAS) and children with speech sound disorder (SSD). What this paper adds to existing knowledge We found that children with DLD and children with CAS show low vowel competence compared to children with typical development. A nuanced examination of vowel error types further revealed that children with DLD and children with CAS show weaknesses in encoding and memory. Motor planning and programming weaknesses were unique to CAS. Children with SSD show more mild processing deficits and their performance did not significantly differ from any of the other three groups. What are the clinical implications of this work? Examining the types of vowel errors produced by children with DLD, children with CAS and children with SSD in NWR allows us to further specify the underlying processing weaknesses that differentiate these three groups. This research informs theoretical accounts of language processing in children with different types of speech and language disorders and has the potential to improve the diagnostic utility of NWR tasks.

Dissociating the impact of alexithymia and impaired self-awareness on emotional distress and aggression after traumatic brain injury.

Alexithymia, a deficit in identifying and describing feelings, is prevalent in traumatic brain injury (TBI). Sometimes referred to as "emotional unawareness," we sought to investigate whether alexithymia after TBI was related to, or distinct from, impaired self-awareness (ISA) and whether the two predicted differentiable emotional and aggression profiles. Further, the mediating role of frontal system behaviors (disinhibition, dysexecutive function, apathy) was explored. Participants with TBI (N = 40) from diverse backgrounds completed self-report measures of alexithymia, emotional distress, aggression, and frontal system behaviors. For the assessment of ISA, significant other ratings were obtained to identify discrepancies from self-ratings. Data were analyzed quantitatively using independent samples t tests, correlations, partial correlations, and simple mediation. There was a negative correlation between alexithymia and ISA. Alexithymia, but not ISA, was associated with higher expressions of emotional distress and aggression even after controlling for the effects of ISA via partial correlations. Exploratory analyses found that frontal system behaviors mediated the relationships between alexithymia and aggression and alexithymia and emotional distress. Alexithymia is more accurately conceptualized as an emotional processing deficit than an awareness deficit. Indeed, self-awareness may be a prerequisite for the ability to identify alexithymic tendencies. Negative psychological effects of alexithymia are compounded by poorer executive function and disinhibition and call for the development of TBI-specific alexithymia screening tools and interventions. Alexithymia interventions are best delivered in conjunction with rehabilitation of emotion regulation and executive function. (PsycInfo Database Record (c) 2024 APA, all rights reserved).