Biology subjects

Orf, M.

Publications and source records attributed to Orf, M..

3 recordsLinked to original sources

bioRxiv2025

Neural Tracking of the Maternal Voice in the Infant Brain

Infants preferentially process familiar social signals, but the neural mechanisms underlying continuous processing of maternal speech remain unclear. Using EEG-based neural encoding models based on temporal response functions, we investigated how 7-month-old human infants track maternal vs. unfamiliar speech and whether this affects simultaneous face processing. Infants (13 boys, 12 girls) showed stronger neural tracking of their mothers voice, independent of acoustic properties, suggesting an early neural signature of voice familiarity. Furthermore, central encoding of unfamiliar faces was diminished when infants heard their mothers voice and face-tracking accuracy at central electrodes increased with earlier occipital face tracking, suggesting heightened attentional engagement. However, we found no evidence for differential processing of happy vs. fearful faces, contrasting previous findings on early emotion discrimination. Our results reveal interactive effects of voice familiarity on multimodal processing in infancy: while maternal speech enhances neural tracking, it may also alter how other social cues, such as faces, are processed. The findings suggest that early auditory experiences shape how infants allocate cognitive resources to social stimuli, emphasizing the need to consider cross-modal influences in early development. Significance statementHow infants continuously process familiar social signals and how this familiarity shapes perception has remains unknown. Here we demonstrate that infants brains preferentially track maternal speech over unfamiliar voices, highlighting the early tuning of the auditory system to socially relevant signals. Moreover, the maternal voice modulates the neural encoding of concurrently presented faces without eliciting emotion-specific differences. These findings underscore the role of caregiver signals in shaping multisensory integration during early development.

neuroscience↗

bioRxiv2024

Does amplitude compression help or hinder attentional neural speech tracking?

Amplitude compression is an indispensable feature of contemporary audio production and especially relevant in modern hearing aids. The cortical fate of amplitude-compressed speech signals is not well-studied, however, and may yield undesired side effects: We hypothesize that compressing the amplitude envelope of continuous speech reduces neural tracking. Yet, leveraging such a compression side effect on unwanted, distracting sounds could potentially support attentive listening if effectively reducing their neural tracking. In this study, we examined 24 young normal-hearing (NH) individuals, 19 older hearing-impaired (HI) individuals, and 12 older normal-hearing individuals. Participants were instructed to focus on one of two competing talkers while ignoring the other. Envelope compression (1:8 ratio, loudness-matched) was applied to one or both streams containing short speech repeats. Electroencephalography (EEG) allowed us to quantify the cortical response function and degree of speech tracking. With compression applied to the attended target stream, HI participants showed reduced behavioural accuracy, and compressed speech yielded generally lowered metrics of neural tracking. Importantly, we found that compressing the ignored stream resulted in a stronger neural representation of the uncompressed target speech. Our results imply that intelligent compression algorithms, with variable compression ratios applied to separated sources, could help individuals with hearing loss suppress distraction in complex multi-talker environments. Significant statementAmplitude compression, integral in contemporary audio production and hearing aids, poses an underexplored cortical challenge. Compressing the amplitude envelope of continuous speech is hypothesized to diminish neural tracking. Yet, capitalizing on this compression side effect for distracting sounds might enhance attentive listening. Studying normal-hearing (NH), older hearing-impaired (HI), and older normal hearing individuals in dual-talker scenarios, we applied envelope compression to speech streams. Both NH and HI participants showed diminished neural tracking with compression on the speech streams. Despite weaker tracking of a compressed distractor, HI individuals exhibited stronger neural representation of the concurrent target. This suggests that adaptive compression algorithms, employing variable ratios for distinct sources, could aid individuals with hearing loss in suppressing distractions in complex multi-talker environments.

neuroscience↗

bioRxiv2022

Auditory neural tracking reflects target enhancementbut not distractor suppression in a psychophysically augmented continuous-speech paradigm

Selective attention modulates the neural tracking of speech in auditory cortical regions. It is unclear whether this attention modulation is dominated by enhanced target tracking, or suppression of distraction. To settle this long-standing debate, we here employed an augmented electroencephalography (EEG) speech-tracking paradigm with target, distractor, and neutral streams. Concurrent target speech and distractor (i.e., sometimes relevant) speech were juxtaposed with a third, never task-relevant speech stream serving as neutral baseline. Listeners had to detect short target repeats and committed more false alarms originating from the distractor than the neutral stream. Speech tracking revealed target enhancement but no distractor suppression below the neutral baseline. Speech tracking of the target (not distractor or neutral speech) explained single-trial accuracy in repeat detection. In sum, the enhanced neural representation of target speech is specific to processes of attentional gain for behaviourally relevant target speech rather than neural suppression of distraction.

neuroscience↗