Biology subjects

Escera, C.

Publications and source records attributed to Escera, C..

6 recordsLinked to original sources

bioRxiv2025

An auditory "low road" for threat in humans sensitive to fast temporal cues

Rapid threat processing is crucial for survival. In vision, neural models of emotion propose the existence of direct pathways, or "low roads", from visual thalamus to the amygdala, which may rely on magnocellular inputs and thereby enable rapid processing of threat signals. In audition, evidence from non-human animals points to the existence of a similar fast direct pathway, but its presence in humans remains unknown. Building on animal evidence that high-rate amplitude-modulated (highAM) sounds preferentially engage magnocellular processing, we used behavioral, physiological, and neuroimaging measures to search for an auditory "low road" for threat in humans responsive to magnocellular-associated features. Specifically, we tested whether highAM threat cues elicit rapid affective responses, and whether highAM threat processing aligns with structural thalamo-amygdala connectivity. We recorded electroencephalography and pupillometry from participants while they detected voices during fear conditioning. Emotional voices presented at highAM rates, as opposed to lowAM, elicited threat-related responses during the earliest post-stimulus window. A further study combining functional and diffusion-weighted imaging revealed that selective amygdala responses to highAM threatening voices were functionally associated with individual fiber density of an auditory thalamo-amygdala pathway. These results provide convergent functional and anatomical evidence supporting a subcortical pathway for auditory threat processing, consistent with evolutionarily conserved emotional systems.

neuroscience↗

bioRxiv2025

Psychoacoustic Study of the Rock Art Sites of Cuevas de la Arana (Bicorp, Spain)

Acoustics play a crucial role in shaping our perception of sound and its emotional impact. The rock art site of Cuevas de la Arana in Bicorp, Spain, is an archaeological site where pre-historic communities gathered for social and ritual activities. Cuevas de la Arana exhibits acoustical characteristics that could have enhanced the sensory and emotional impact during ceremonies performed with music. In the present study, a listening test was conducted to assess how the acoustics of Cuevas de la Arana and other rock art sites influence modern-day listeners perception of sound. Listeners were asked to describe, using their own vocabulary, a series of auralizations created with the impulse responses collected in Cuevas de la Arana and other neighboring sites with and without rock art. The words written by participants underwent categorization through a hierarchical clustering approach. Significant results emerged indicating that listeners perceived auralizations from rock art sites as larger, wider, less direct, farther and more reverberant than the auralizations from sites lacking rock art. Notably, the most prominent disparities were observed in the categories of size, distance, and reverberation when contrasting the auralizations from Cuevas de la Arana with those of non-painted sites. These findings align with the outcomes documented in prior literature that investigated the acoustic characteristics of the sites and offer valuable insights into the auditory experiences at rock art sites, shedding light on their unique acoustic properties.

animal behavior and cognition↗

bioRxiv2024

Bilingual Exposure and Sex Shape Developmental Trajectories of Brain Responses to Speech-Sound Features in Infants

As the auditory brain becomes functional during the third trimester of pregnancy, both biological and environmental processes begin shaping its maturation, influencing how speech sounds are perceived. Biological factors, such as sex, introduce early genetic differences, while environmental experiences, like bilingualism, modulate the auditory input that infants receive. Although existing research highlights the impact of sex and bilingualism on the development of speech perception, the neural mechanisms remain unclear. In this study, we recorded frequency-following responses (FFRs) longitudinally, at birth, six months, and twelve months of age in 73 infants exposed to varying degrees of bilingual input. We modeled the developmental trajectories for neural encoding of voice pitch and speech formant structure, finding significant maturation during the first six months, followed by stabilization through the first year. Distinct developmental patterns emerged as a function of sex and bilingualism, revealing their influence on neural attunement to key speech-sound features. Bilingual exposure notably predicted lower neural pitch encoding values at six months, but higher values by twelve months. A positive effect of bilingualism on speech formant encoding was observed throughout the first year. These findings reveal how biological and environmental factors contribute to individual variability in early auditory development and speech acquisition. HighlightsO_LIBilingualism and sex impact early developmental trajectories in neural speech encoding C_LIO_LIResults suggest a female advantage in early neural encoding of speech-sound features C_LIO_LIBilingual exposure positively modulates infant neural speech encoding C_LI

developmental biology↗

bioRxiv2024

Exposure to bilingual or monolingual maternal speech during pregnancy affects the neurophysiological encoding of speech sounds in neonates differently

Exposure to maternal speech during the prenatal period shapes speech perception and linguistic preferences, allowing neonates to recognize stories heard frequently in utero and demonstrating an enhanced preference for their mothers voice and native language. Yet, with a high prevalence of bilingualism worldwide, it remains an open question whether monolingual or bilingual maternal speech during pregnancy influence differently the fetus neural mechanisms underlying speech sound encoding. In the present study, the frequency-following response (FFR), an auditory evoked potential that reflects the complex spectrotemporal dynamics of speech sounds, was recorded to a two-vowel /oa/ stimulus in a sample of 131 healthy term neonates within the 1-3 days after birth. Newborns were divided into two groups according to maternal language usage during the last trimester of gestation (monolingual; bilingual). Spectral amplitudes and spectral signal-to-noise ratios (SNR) at the stimulus fundamental (F0) and first formant (F1) frequencies of each vowel were respectively taken as measures of pitch and formant structure neural encoding. Our results reveal that while spectral amplitudes at F0 did not differ between groups, neonates from bilingual mothers exhibited a lower spectral SNR. Additionally, monolingually exposed neonates exhibited a higher spectral amplitude and SNR at F1 frequencies. We interpret our results under the consideration that bilingual maternal speech, as compared to monolingual, is characterized by a greater complexity in the speech sound signal, rendering newborns from bilingual mothers more sensitive to a wider range of speech frequencies without generating a particularly strong response at any of them. Our results contribute to an expanding body of research indicating the influence of prenatal experiences on language acquisition and underscore the necessity of including prenatal language exposure in developmental studies on language acquisition, a variable often overlooked yet capable of influencing research outcomes.

neuroscience↗

bioRxiv2024

Assessing the relationship between neural entrainment and altered states of consciousness induced by electronic music

In electronic music events, the driving four-on-the-floor music appears pivotal for inducing altered states of consciousness (ASCs). While various physiological mechanisms link repetitive auditory stimuli to ASCs, entrainment--a brainwave synchronization through periodic external stimuli-- has garnered primary focus. However, there are no studies systematically exploring the relationship between entrainment and ASCs. In the present study, we depart from the finding that entrainment to auditory stimuli peaks for stimulation rates around 2 Hz compared to others. Twenty participants listened to six one-minute electronic music excerpts at different tempos (1.65 Hz, 2.25 Hz, and 2.85 Hz). For each excerpt, they performed cognitive tasks and reported phenomenological experiences related to ASCs through questionnaires. Brain activity was recorded with electroencephalography to assess whether a modulation in entrainment by the beat of electronic music affected objective and subjective proxies of ASCs. Our results revealed a tempo-driven entrainment modulation, peaking at 1.65 Hz. Similarly, participants experience of unity during listening to the music was higher for the excerpts at 1.65 Hz, yet no relationship with entrainment was found. Critically, a correlation was found between entrainment and participants reaction time. Further studies are granted to explore how individual traits, such as musical training, modulate the relationship.

neuroscience↗

bioRxiv2023

Longitudinal trajectories of the neural encoding mechanisms of speech-sound features during the first year of life

Infants quickly recognize the sounds of their mother language, perceiving the spectrotemporal acoustic features of speech. However, the underlying neural machinery remains unclear. We used an auditory evoked potential termed frequency-following response (FFR) to unravel the neural encoding maturation for two speech sound characteristics: voice pitch and temporal fine structure. The FFR was elicited by a two-vowel stimulus (/oa/) in a sample of 41 healthy-term neonates, tested at birth and retested at the ages of six and twelve months. Results revealed a reduction in neural phase-locking time to the stimulus envelope from birth to six months, remaining stable thereafter. While neural encoding of voice pitch remained consistent, temporal fine structure encoding matured rapidly from birth to six months, without further improvement from this age onwards. Results highlight the critical importance of the first six months in the maturation of neural encoding mechanisms, crucial for phoneme discrimination during early language acquisition.

neuroscience↗