Developmental language disorder (DLD) is a persistent difficulty in the acquisition and use of expressive and/or receptive language, which negatively impacts academic and social development. The present study evaluated the validity of the statistical learning model proposed to account for language difficulties in children with DLD. To this end, two auditory paradigms of varying complexity, framed within predictive coding theory, were passively presented to children diagnosed with DLD and to typically developing children without neurological impairments. The paradigms consisted of stimulus sequences with decreasing or increasing frequencies, interspersed with the sporadic occurrence of unexpected tone endings. The psychophysiological response was recorded using EEG, focusing on the P1, mismatch negativity (MMN), postimperative negative variation (PINV), and contingent negative variation (CNV) components. Results showed an absent MMN and a higher P1 response to deviant tones in children with DLD, suggesting an impaired development of frontal MMN generators, potentially compensated by activity in the primary auditory cortex. DLD participants also showed increased PINV and CNV responses during the most complex paradigm, which could imply greater cognitive effort and resource allocation for reassessment of stimulus patterns. Finally, incomplete maturation of frontal areas in children within this age range (3-11 years) was proposed as a possible explanation for the absence of differences between groups in P1 and N1/MMN responses elicited by simple and complex conditions. These findings support statistical learning as a valid model for understanding the possible neural basis of DLD and highlight this predictive EEG design as a potential protocol for early detection.

Predictive coding conceptualizes attention as a weighting of prediction error signals. However, empirical findings on how attention influences common markers of prediction error have been inconsistent, likely because these markers are typically derived from stimulus-evoked responses. To avoid stimulus-related confounds and isolate effects related purely to prediction, we investigated how attention modulates brain responses to unexpected stimulus omissions. Using visual-auditory couplings where the auditory stimulus was occasionally omitted, we recorded EEG responses that revealed a multistage omission response-from early sensory to later higher-level prediction error activity. Voluntary attention was manipulated along two dimensions: (1) toward the visual or auditory modality, and (2) toward the moment of stimulus presentation or sustained over time. Early sensory prediction error, reflected by the omission N1, was unaffected by any manipulation of attention. In contrast, later high-level prediction error processing, reflected by omission P3 responses, was strongly affected by directing attention: robust responses were elicited when attention was directed to the auditory modality-where the prediction had been violated-but these were markedly reduced or absent when attention was directed to the visual modality. These results suggest an attentional system that does not affect low-level sensory prediction error but is capable of influencing distinct stages in the processing hierarchy in service of task performance. This first investigation of how attention affects different stages of omission activity suggests that voluntary attention may modulate prediction error processing via specific neurotransmitter systems and demonstrates this approach's potential for reliably studying precision-weighting in the brain.

The presence of another human in our immediate or distant environment is a crucial factor for survival and social behavior. Our actions vary depending on the other person's relative proximity, involving integration of brain functions subserved by neural oscillations, to generate the most appropriate behavior. This study highlights the alpha EEG role and its neural generators in interpersonal space sensitivity (IPSS). To investigate this, participants stood face-to-face, gazing into each other's eyes, while wearing a mask preventing them from staring at each other. An auditory order instructed them to alternately close and open their eyes. It was observed that alpha power of the occipito-parietal region increased as the distance decreased, transitioning from extrapersonal space (4 m) to peripersonal space (< 40 cm) when the eyes were closed. Conversely, alpha power decreased for the same distances when the eyes were open. These significant event-related synchronization (ERS) and desynchronization (ERD) effects were absent when participants' heads were masked. Beta oscillations were not significantly involved in IPSS. The number of spontaneous blinks was not significantly influenced by IPSS. Source modeling identified alpha ERS and ERD in cortical and subcortical generators significantly involved in IPSS with independent components localized in: the parietal cortex bilaterally (BA7), the left limbic gyrus (BA23), the anterior cingulate cortex (ACC) (right BA31, left and right BA24, right BA32), the right premotor cortex (BA6, including the supplementary motor area [SMA]), and the right frontal eye fields (BA8). These cortical areas were accompanied by the recruitment of the thalamus and cerebellum.

ImportanceHistopathological findings are important to guide our decision between cochlear and auditory brainstem implant in inner ear malformations (IEM) with cochlear hypoplasia (CH), incomplete partition (IP), and common cavity.ObjectiveCochlear implantation (CI) has variable outcome in IEM. Histopathology of IEM is evaluated to understand the causes of this variation.DesignEvaluation of human temporal bone specimens with IEM.ParticipantsTwenty temporal bone specimens from 10 donors who had IEMs were evaluated.Main outcome measuresClassification of IEM and analysis of cochlear morphology [inner and outer hair cells, spiral ganglion cells, and cochlear nerve (CN)] to understand the functional outcome of implantation.ResultsAmong the temporal bones with IEMs, 16 were classified as CH, 2 were IPs type II, and 2 had a normal cochlear anatomy, but absent CNs. The CN was hypoplastic in 3 specimens with CH-III. The nerve was lying adjacent to the bony wall, which would be difficult to demonstrate with current magnetic resonance imaging (MRI). The mean percentage of loss of spiral ganglion cells in CH-III among our specimens was 62%. Some specimens showed asymmetric development, which will play a crucial role in the benefit from CI. Two specimens from the same donor with a fully-developed cochlea demonstrated absent CN.ConclusionBetter MRI sequences are needed to demonstrate the hypoplastic CN adjacent to the wall of the internal auditory canal. Audiological examination is of paramount importance to demonstrate the presence of neural connection between the cochlea and the brainstem. In asymmetric developments between 2 sides, more developed side should be chosen for CI. Depending on the findings cochlear or auditory brainstem implants may be chosen for the contralateral findings. If there is only one implant available, the side with the better developed CN should be picked.

Body movements like walking can synchronize with auditory and visual inputs presented within a periodic frequency range, peaking around 2 Hz. Some evidence has shown that the spontaneous tempo of human locomotion is around 2 Hz. The EEG frequency-tagging approach allows us to capture the coupling of beat perception with neural brain oscillations at beat frequency. This study used EEG frequency tagging to explore brain dynamics during the perception of walking-related sensory information in the auditory (footstep sounds) and visual (point-light figure) modalities. Sensory inputs were delivered at different rates (1, 2, and 3.6 Hz) in rhythmic or random sequences while recording EEG activity. The experiment included three conditions: (i) auditory, (ii) visual, and (iii) audiovisual, including data from 22 participants. Results showed a main effect of rhythmic sequences compared with random sequences across all frequencies in all three auditory, visual, or audiovisual conditions. Specifically, at 2 Hz, rhythmic sequences enhanced neural entrainment in the sensorimotor cortex for auditory and audiovisual conditions. This effect was absent in the visual condition alone. Notably, 2 Hz rhythmic sequences in the audiovisual condition led to coupling with temporal, sensorimotor, and occipital regions. The study suggests that sensory auditory input related to walking movement presented at 2 Hz can mediate neural entrainment with sensorimotor areas. The findings of this study can have an impact on the spontaneous rhythmic integration of body movements using sensory inputs for walking rehabilitation.

Differentiating self-generated from externally induced sounds is crucial for survival. Predictions can be generated based on action-outcome contingency and suppress neural responses to sensory reafference for distinguishing the origin of stimuli. The action-outcome contingency can be flexible or relatively fixed (e.g., keypress could trigger various sounds vs. articulatory gestures generate corresponding speech sounds) and can be available during the entire course of action (including stages of intention, preparation and execution). Are motor-based predictions created equally based on different types of action-outcome contingency and during distinct stages of action? We conducted three EEG experiments to determine how motor preparation modulates auditory processing using a delayed keypress paradigm in which participants prepared to press a key to trigger a sound without knowing what key to press. In Experiment 1, keypress preparation showed overall enhanced N1 responses (∼100 ms), largest for syllables, but did not reveal any suppression effects. Experiment 2 replicated N1 enhancement and showed significant P2 suppression (∼200 ms) in response to auditory syllables, when participants were pianists who had extensive keypress-sound mapping experience. Experiment 3, when pianists were in their unfamiliar pairing of lab keys and familiar piano tones, again showed N1 enhancement, but the P2 suppression was absent. Together, these results suggest that preparatory motor prediction in an optional mapping can influence auditory processing in multiple directions and motivate a two-stage gain-to-attenuation hypothesis that may depend on the precision (reliability) of action-outcome associations.

Ramsay Hunt syndrome (herpes zoster oticus) is an uncommon neurological complication of varicella-zoster virus (VZV) reactivation caused by inflammation of the geniculate ganglion of cranial nerve VII. While Ramsay Hunt syndrome classically affects cranial nerve VII, concomitant involvement of cranial nerve VIII is well described. The classic triad includes unilateral lower motor neuron facial paralysis, otalgia, and vesicular rash in the auricle or auditory canal. Atypical presentations without these features are recognized and may delay diagnosis. We report an 82-year-old man with recent herpes zoster oticus who developed acute vestibular syndrome with gait instability, left-beating nystagmus, and vertical diplopia. He had left ear and temporal pain but no facial weakness. Contrast-enhanced MRI showed enhancement of cranial nerves VII and VIII in the cerebellopontine angle without clinical facial motor deficit. Following sequential antiviral therapy (intravenous acyclovir followed by oral valacyclovir) and corticosteroids, diplopia and nystagmus resolved within one week with substantial gait improvement by four weeks. This case highlights Ramsay Hunt syndrome presenting with predominant vestibulocochlear dysfunction despite radiographic facial nerve involvement. Prompt antiviral and corticosteroid therapy can prevent permanent sequelae such as sensorineural hearing loss or neurotrophic keratitis. Clinicians should maintain a high index of suspicion for VZV-related cranial polyneuropathy in older adults with acute vestibular syndrome after recent zoster, even in the complete absence of facial palsy.

Vogt-Koyanagi-Harada (VKH) disease is a T cell-mediated autoimmune attack on melanocytes in the eyes, ears, skin, and central nervous system. It is characterized by granulomatous panuveitis and often results in significant visual loss. We report a 60-year-old woman referred for suspected chorioretinal inflammation following one month of treatment for anterior uveitis. Remarkably, visual acuity was preserved at 6/6 in both eyes. There was no history of ocular surgery or trauma. Examination revealed trace anterior chamber cells and mild anisocoria. Choroidal folds were present without serous retinal detachment, and the inflammation resolved with topical corticosteroids. At five months, progressive choroidal hypopigmentation resulted in a sunset glow fundus. As no neurological or auditory features were present, the diagnosis initially suggested probable VKH. However, the later development of a single forehead vitiligo patch led to the diagnosis of incomplete VKH. During the acute uveitic stage, a benign liver mass was identified alongside elevated liver enzymes and CA 19-9 tumor marker, which subsequently normalized. Ophthalmologists should be aware of atypical presentations of VKH, particularly in older adults, where systemic symptoms may be mild, absent, or delayed. Vision can remain preserved in the absence of serous retinal detachment. Although the precise triggers of VKH remain unclear, immunological activation has been associated with factors such as immune checkpoint inhibitors, vaccinations, viral infections, and coexisting autoimmune diseases. In this case, a coincidental liver mass was observed, with a transient elevation in tumor marker and liver enzymes. Further case reports are needed to clarify whether such immunoinflammatory changes play a role in initiating autoimmune VKH or represent incidental findings.