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.

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.