Noonan syndrome (NS) is a clinically heterogeneous condition caused by pathogenic variants in genes of the RAS/MAPK signaling pathway, presenting as a spectrum of phenotypic features rather than a single uniform disorder. We report two unrelated female pediatric patients evaluated for LZTR1-related NS following whole-exome sequencing. The first patient presented with isolated short stature, subtle dysmorphic features, and normal neurodevelopment. The second displayed multisystem involvement including developmental delay, skeletal abnormalities, and auditory processing disorder. A heterozygous pathogenic variant in LZTR1 was confirmed in the first patient, while the second carried a heterozygous LZTR1 variant of uncertain significance, rendering her diagnosis provisional. Neither patient had congenital heart defects. These cases illustrate the marked phenotypic variability of LZTR1-related NS and underscore that, while cardiac defects may be absent in some individuals, appropriate cardiac surveillance remains necessary.

Age-related hearing loss (ARHL) is associated with difficulty understanding speech in complex listening environments, yet its neural basis remains unclear. We combined behavioral measures with functional near-infrared spectroscopy (fNIRS) to examine speech perception and neural responses during cocktail-party listening. Sixty-eight participants (Young-NH, Older-NH, ARHL) completed a spatialized speech-recognition task under different masker types and signal-to-noise ratios, together with resting-state and task-based fNIRS recordings. ARHL showed poorer speech perception and reduced self-reported hearing ability across listening conditions. At rest, ARHL exhibited increased frontotemporal connectivity and greater local network organization. During the task, cortical responses showed a group gradient, with attenuation in Older-NH and predominantly negative responses in ARHL, and diminished modulation by listening demands. In addition, brain-behavior coupling observed in Young-NH was absent in both older groups. These findings indicate that speech perception deficits in ARHL are associated with altered neural responses and reduced flexibility in adapting to listening demands, accompanied by disrupted brain-behavior relationships.

Skin conductance responses (SCRs) are a standard index of sympathetic arousal, yet a notable proportion of individuals show low or absent SCRs and are routinely excluded from analyses. Such exclusions may reduce the representativeness of psychophysiological research and obscure genuine individual differences in autonomic responsivity. In this study, we combined conventional threshold-based classification with hierarchical and Bayesian mixture modeling to examine the continuum of SCR reactivity in 269 adults completing an auditory novelty task. Using the standard 0.02 µS criterion, 16% (42 of 261 with usable data) met non-responder criteria, meaning roughly one in six participants would typically be excluded. Among responders, a Dirichlet Process Gaussian Mixture Model revealed three latent subgroups, low-, moderate-, and high-reactive, demonstrating graded variation in SCR amplitude even within the conventionally defined responder group. Hierarchical modeling further indicated that non‑responders exhibited low‑amplitude, stimulus‑indexed SCR structure recoverable within a generative modeling framework, despite amplitudes near conventional detection thresholds. Demographic predictors were minimal, with only age showing a modest negative association with responsivity, and psychological symptoms were unrelated. Together, these findings indicate that autonomic responsivity varies continuously both within and beyond responder classification, and that rigid amplitude thresholds may obscure meaningful physiological diversity. A hybrid analytic approach that integrates traditional criteria with model-based quantification can provide a more inclusive and representative view of human autonomic variability.

There is substantial support for the idea that the listening brain makes predictions about upcoming speech and that these predictions are integrated with sensory input to influence perception. For example, the early auditory encoding of words appears to vary based on how those words semantically relate to their preceding context, suggesting that top-down information might feed back to affect acoustic speech processing. However, the way in which speakers enunciate words can vary based on how well those words fit with their preceding context. This presents a potential confound to the interpretation of top-down prediction in the listener. In this study, we address this possibility by assessing the influence of probability-based predictions (word surprisal) on electroencephalographic (EEG) indices of acoustic speech processing while controlling for variations in speaker dynamics. We analyzed EEG from 14 adults who undertook a perceptual pop-out task in which prior information enhanced the comprehensibility of degraded speech while acoustic information was held constant. Behavioral results confirmed the manipulation's effectiveness and were mirrored in the neural indices of word surprisal processing. Importantly, a positive relationship between word surprisal and EEG tracking of word acoustics emerged for degraded speech when prior information rendered it intelligible, but was absent when it was unintelligible, despite identical acoustic input across conditions. The difference in neural effects between conditions also correlated with the corresponding difference in behavioral pop-out. These findings support the claim that top-down word predictability influences the acoustic encoding of natural speech, independent of variations in speaker enunciation.

Closed captions, originally for hearing-impaired audiences, are now increasingly used, adding an additional visual element to the multisensory experience of movie viewing. This study examines how gaze behavior adapts to the absence of auditory information by testing whether increased caption engagement reflects more frequent switching between closed captions and the visual scene, longer uninterrupted reading intervals, or both. Using eye-tracking, we analyzed saccades and fixations in designated areas of interest as participants viewed a 20-minute movie with alternating presence and absence of audio. Viewers integrated the two visual input streams by frequently shifting their gaze between the captions and the scene. The balance between reading captions and watching visuals shifts in the absence of sound by adjusting transition probabilities (i.e., increasing gaze switching between captions and scene, rather than changing the duration of reading intervals). This suggests that increased caption engagement in the absence of sound reflects more frequent sampling of captions, rather than longer uninterrupted reading. Modeling the probabilistic characteristics of fixations and saccades revealed more consistent and focused eye movement patterns on the caption text compared to the visual scene, highlighting distinct reading and gazing behaviours. Notably, these differences remained stable regardless of the presence or absence of sound. In addition to the availability of audio, we observed the presence of dialogue and the emotional content also influence caption engagement. These findings highlight how viewers adapt to missing audio through more frequent switching between text and scene while maintaining low-level properties of eye movements.

This case report presents successful bilateral cochlear implantation (CI) in a pediatric patient with neurobrucellosis complicated by bilateral profound sensorineural hearing loss (SNHL) and irreversible bilateral vision loss. The report highlights the positive impact of CI on auditory perception and speech development in this complex clinical context. A 14-year-old girl developed acute bilateral blindness and subsequently experienced rapidly progressive bilateral SNHL despite appropriate antibiotic therapy for neurobrucellosis. In the 12th month following the onset of neurobrucellosis symptoms, she developed bilateral profound SNHL. Comprehensive preoperative audiological evaluation-including pure-tone audiometry, otoacoustic emissions, and auditory brainstem response testing-revealed absent otoacoustic emissions and cochlear microphonics, with no wave V responses at 100 dB nHL bilaterally. These findings functionally excluded auditory neuropathy spectrum disorder and indicated cochlear hair cell involvement rather than retrocochlear or central auditory pathway dysfunction, supporting the potential for favorable CI outcomes. Bilateral CI was performed via the transmastoid facial recess approach within one month after the diagnosis of bilateral profound SNHL. Postoperative outcomes were excellent, with a Categories of Auditory Performance score of 7 and 100% sentence recognition at 22 months postoperatively. Vision loss remained unchanged. This case underscores that, although neurobrucellosis-related SNHL may theoretically affect any part of the auditory pathway, timely diagnosis and appropriate patient selection can provide satisfactory hearing and speech outcomes through CI in pediatric neurobrucellosis.

Background High-risk pregnancies increase the likelihood of neonatal hearing impairment, yet early signs are often subtle or absent, delaying diagnosis. Early identification through newborn hearing screening is critical to prevent long-term auditory and developmental deficits. Objective To evaluate neonatal hearing screening outcomes using Automated Auditory Brainstem Response (AABR) in neonates born through high-risk pregnancies at Dhulikhel Hospital. Method In this prospective study, neonates born between 15th March 2023 and 15th September 2024 through high-risk pregnancies were screened using Automated auditory brainstem response within 24 hours of birth. Neonates failing the initial screening were re-tested at six weeks. Maternal risk factors including hypothyroidism, diabetes, hypertension, pre-eclampsia, renal disorders, STDs, psychiatric disorders, heart disease, smoking, and extreme maternal age were recorded. Neonates failing the second screening were referred and tested with diagnostic automated auditory brainstem response . Result Ninety neonates (41 males, 49 females) were included. Thirty-two neonates failed the initial automated auditory brainstem response , and nine failed the second screening, yielding a referral rate of 10%. Maternal hypothyroidism was the most common risk factor among referred cases. Other maternal factors associated with referrals included diabetes, maternal age ≥ 35 years, pre-eclampsia, smoking, and STDs. The overall diagnostic automated auditory brainstem response failure rate was 3.3%, highlighting the low but significant prevalence of hearing impairment among high-risk pregnancies. Conclusion Maternal health conditions, particularly hypothyroidism, diabetes, and advanced maternal age, are associated with increased risk of neonatal hearing impairment. automated auditory brainstem response is an effective screening tool in high-risk populations, and early detection with timely intervention is essential to optimize auditory and developmental outcomes.

Background/Objectives: Auditory neuropathy is a form of hearing loss marked by preserved outer hair cell function and abnormal or absent auditory brainstem responses. Monogenic causes play a significant role in its aetiology. This systematic review aims to identify the genetic causes of auditory neuropathy reported in the literature and to determine the diagnostic yield of genetic testing in affected individuals. Methods: A systematic search of MEDLINE, Embase, and PubMed was conducted. Studies were included if participants had a diagnosis of auditory neuropathy and if genetic testing results were reported with variant interpretation based on American College of Medical Genetics and Genomics criteria. Results/Discussion: Twenty-nine studies involving 441 children and adults with auditory neuropathy were included. Overall, 21 different genes and 136 pathogenic and likely pathogenic variants were found to be causative of auditory neuropathy, with both syndromic and non-syndromic presentations. Variants in OTOF were the most common cause, responsible for 59% of all genetic diagnoses found. A genetic diagnosis was confirmed in 195 of 362 individuals who underwent genetic testing, resulting in a diagnostic yield of 54%. After adjusting for study bias and new gene associations with AN, the diagnostic yield was 31%. Conclusions: This review identifies gene and variant-level associations with auditory neuropathy that enhance our understanding of the condition. It highlights the high diagnostic yield of genetic testing in auditory neuropathy which supports consideration of genetic testing early in the diagnostic pathway. A genetic diagnosis may support precision-based approaches to treatment, including cochlear implants and participation in gene therapy trials.

Monitoring how attention is distributed across concurrent task demands is fundamental in daily life contexts such as mobility, education and industrial control. However, existing neurophysiological measures, typically based on univariate EEG markers, are sensitive to generic cognitive load, visual complexity, or motor activity, and therefore lack specificity for attentional splitting. Here, we introduce the Attentional Split Index (ASI), a novel EEG-based metric that employ Mutual Information (MI) theory, designed to quantify the coordinated modulation of multiple neurometrics that emerges when attention is divided across tasks. Twenty-five participants completed a realistic driving protocol combining a main driving task in two different environments (Urban, Highway) with four types of attentional-split demands, i.e., Focused, Auditory Continuous Performance Test (ACPT), Matrix, Surrogate Reference Task (SURT). Traditional neurometrics (parietal alpha, inverse frontal beta, frontal theta/beta ratio) exhibited partial sensitivity to task demands but failed to selectively reflect attentional splitting. In contrast, the ASI showed a robust and systematic increase across conditions, distinguishing not only explicit multitasking segments but also subtler differences between Urban and Highway focused driving. Eye-tracking and subjective distraction rating showed a strong and significant correlation with the ASI (Urban: rET = 0.515 and rSUB = 0.744; Highway: rET = 0.357 and rSUB = 0.673; all p < 10-2), confirming high behavioural and phenomenological coherence. Surrogate analyses demonstrated that ASI effects were absent when temporal coordination across neurometrics was artificially disrupted, and that real ASI exceeded surrogate values in the vast majority of participants during multitasking but not during eyes-open baseline. Together, these findings establish the ASI as a specific, robust, and ecologically coherent neural marker of attentional splitting, with promising implications for neuroergonomics and next-generation adaptive human-machine systems.

Morquio A syndrome (mucopolysaccharidosis IVA) is a lysosomal storage disorder characterized by systemic skeletal dysplasia and multisystem involvement. Hearing loss is frequently reported but remains insufficiently characterized, with few studies incorporating comprehensive behavioral and electrophysiologic assessments. In this prospective study, the largest Morquio A auditory cohort to date, participants underwent detailed audiologic and imaging testing at Nemours Children's Health as part of the National Institutes of Health-sponsored natural history program. Assessments included pure-tone thresholds, speech-recognition thresholds, speech perception in quiet and noise, tympanometry, distortion-product otoacoustic emissions, auditory brainstem responses, and cortical auditory evoked potentials. Outcomes included the prevalence, type, and severity of hearing loss, as well as associations with age and clinical disease severity. Hearing loss was identified in 50.9% of 56 patients, with sensorineural loss more frequent than conductive or mixed types. Prevalence of hearing loss was significantly correlated with clinical severity (height percentile), whereas no significant correlation was observed between hearing loss severity and diagnostic age. Reduced or absent otoacoustic emissions with preserved brainstem and cortical responses indicate predominant cochlear involvement with potential secondary central contributions. Comprehensive imaging of the middle and inner ear showed no significant structural differences between patients with and without hearing loss. Hearing loss is common in Morquio A and is primarily sensorineural. The absence of associations with age or disease severity underscores the heterogeneity of auditory involvement. These findings emphasize the need for routine, comprehensive audiologic monitoring to support early detection and mitigate long-term impacts on communication and quality of life.