Biology subjects

Sotero Silva, N.

Publications and source records attributed to Sotero Silva, N..

4 recordsLinked to original sources

bioRxiv2026

Stability of Eye Movement-Related Eardrum Oscillations to acoustic and gravitational manipulations

Recent studies describe Eye Movement-Related Eardrum Oscillations (EMREOs), low-frequency signals recorded in the ear canal that arise from the tympanic membrane and are triggered by saccadic eye movements. Because EMREOs are thought to arise from motor elements in the peripheral auditory system, we examined how two known modulators of these elements affect the EMREO time course. First, the activity of outer hair cells (OHC) can be suppressed by the medial olivocochlear reflex (MOCR). If OHCs contribute to the generation of EMREOs, activation of this reflex should reduce EMREO amplitude. To test this, we compared EMREO amplitudes elicited by saccades performed in silence and in the presence of contralateral noise. Second, postural (i.e. vestibular and proprioceptive) cues linked to head orientation may influence EMREOs via oculomotor control circuits that possibly modulate middle ear muscles. To test this, we recorded EMREOs while participants made saccades with their head upright (0{degrees} azimuth) and with their head tilted 30{degrees} in either direction. Across both experiments our data reveal no clear modulation of the EMREO time course by these experimental manipulations. Together with other recent studies these findings advocate for a stability of the EMREO time course towards multiple experimental modulations and fuel speculations that the signal may serve as a temporal reference frame rather than a spatial coordinate transform function when combining signals across the senses.

neuroscience↗

bioRxiv2026

Investigating neural speech processing with functional near infrared spectroscopy: considerations for temporal response functions

Functional near infrared spectroscopy (fNIRS) is increasingly used in hearing and communication research, with advantages such as robustness to movement artifacts, improved spatial resolution, and flexibility of contexts in which it can be applied. At the same time, the field is progressively moving towards more continuous, naturalistic listening paradigms resulting in the widespread adoption of speech tracking analyses such as temporal response functions (TRFs) in electroencephalography (EEG) and magnetoencephalography (MEG) studies. However, it remains unclear whether these analyses can be applied to slower haemodynamic signals measured by fNIRS. In the present study, we investigated whether a TRF framework can similarly be applied to fNIRS data recorded during continuous speech perception. Eight participants listened to speech simultaneously while fNIRS signals were acquired in a hyperscanning setup. Speech features were regressed onto the haemodynamic responses to test the feasibility and interpretability of fNIRS-based TRFs. Prediction correlations between observed and modelled fNIRS signals across speech features were higher than those typically reported for EEG- and comparable to those reported for MEG-TRF studies. Moreover, these correlations did not overlap with a null distribution generated from triallJmismatched fNIRS data, confirming statistical significance and were slightly greater than those obtained from a conventional GLM approach. Our findings support that TRF estimation method can yield meaningful and statistically significant responses from fNIRS data. HighlightsO_LITRF modelling can be meaningfully applied to fNIRS data acquired during speech listening tasks. C_LIO_LIPrediction correlations between actual and modelled fNIRS signals were above chance level, with values comparable to previous EEG/MEG studies. C_LIO_LITRFs explained more fNIRS variance than a conventional GLM approach. C_LI

neuroscience↗

bioRxiv2025

Eye Movement-Related Eardrum Oscillations (EMREOs) Do Not Have a Direct Impact on Auditory Spatial Discrimination

Eye-movement-related eardrum oscillations (EMREOs) are pressure changes recorded in the ear that supposedly reflect displacements of the tympanic membrane induced by saccadic eye movements. Previous studies hypothesized that the underlying mechanisms might play a role in combining visual and acoustic spatial information. Yet, whether and how the eardrum moves during an EMREO and whether this movement affects acoustic spatial perception remains unclear. We here probed human acoustic lateralization performance for sounds presented at different times during a saccade (hence the EMREO) in two tasks, one relying on free-field sounds and one presenting sounds in-ear. Since the EMREO generation likely involves the middle ear muscles, whose tension can alter sound transmission, it is possible that judgements of sound locations may vary with the state of the ERMEO at the time of sound presentation. However, when testing two specific hypotheses of how movements of the eardrum underlying the EMREO may affect spatial hearing, we found no evidence in support of this. Still, and in line with previous studies, we found that participants lateralization responses were shaped by the spatial congruency of the saccade target direction and the sound direction. Thus, either the eardrum does not move directly as reflected by the EMREO signal, or despite its movement the underlying changes at the tympanic membrane only have minimal perceptual impact. Our results call for more refined studies to understand how the eardrum moves during a saccade and whether or how the EMREO impacts spatial perception.

neuroscience↗

bioRxiv2024

Unraveling eye movement-related eardrum oscillations (EMREOs): how saccade direction and middle ear properties shape amplitude and time course

Eye movement-related eardrum oscillations (EMREOs) reflect movements of the tympanic membrane that scale with the magnitude and direction of saccades. EMREOs have been consistently described in humans and non-human primates, yet many questions regarding this phenomenon remain unresolved. Based on bilateral in-ear recordings in human participants we here explore several properties of these EMREOs in order to improve our understanding of this signals origin and functional significance. Our data support that the EMREO time course is comparable between the left and right ears, and between paradigms guiding saccades by visual and auditory target stimuli. However, the precise amplitude time course differs significantly between ipsi-and contralateral saccades in addition to the previously known phase-inversion described for saccades in opposing directions. Finally, our data suggest that the EMREO amplitude is negatively related to the compliance of the tympanic membrane as established by tympanometry. Collectively, these results support the notion that EMREOs reflect motor-related top-down signals relayed to the ear from yet-to-be-resolved sources, and fuel the speculation that EMREOs may be generated by the middle ear muscles in a differential operation similar to the execution of ipsi-and contralateral saccades.

neuroscience↗