Carles Escera

University of Barcelona | UB · Institute of Neurosciences

Introduction Infants born very early preterm are at high risk of language delays. However, less is known about the consequences of late prematurity. Hence, the aim of the present study is to characterize the neural encoding of speech sounds in late preterm neonates in comparison with those born at term. Methods The speech-evoked frequency-followin...

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 mother’s voice and native language. Yet, with a high prevalence of bilingualism worldwide, it remains an open question whether...

This systematic review aims to assess the impact of sensorineural hearing loss (SNHL) on various frequency-following response (FFR) parameters. Following PRISMA guidelines, a systematic review was conducted using PubMed, Web of Science, and Scopus databases up to January 2023. Studies evaluating FFRs in patients with SNHL and normal hearing control...

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 sys...

Infants learn to recognize the sounds of their mother language very early in development, exhibiting a remarkable ability to process the fine-grained spectrotemporal characteristics of speech. However, the neural machinery underlying this ability is not yet understood. Here, we used an auditory evoked potential termed frequency-following response (...

Purpose The aim of the present study is to characterize the maturational changes during the first 6 months of life in the neural encoding of two speech sound features relevant for early language acquisition: the stimulus fundamental frequency ( f o ), related to stimulus pitch, and the vowel formant composition, particularly F 1 . The frequency-fol...

There are sounds that most people perceive as highly unpleasant, for instance, the sound of rubbing pieces of polystyrene together. Previous research showed larger physiological and neural responses for such aversive compared to neutral sounds. Hitherto, it remains unclear whether habituation, i.e., diminished responses to repeated stimulus present...

The major goal of psychoarchaeoacoustics is to understand the psychology behind motivations and emotions of past communities when selecting certain acoustic environments to set activities involving the production of paintings and carvings. Within this framework, the present study seeks to explore whether a group of archaeological rock art sites in...

Background: (Central) auditory processing disorders, (C)APDs are clinically identified using behavioral tests. However, changes in attention and motivation may easily affect true identification. Although auditory electrophysiological tests, such as Auditory Brainstem Responses (ABR), are independent of most confounding cognitive factors, there is...

Objectives: The present envelope frequency-following response (FFRENV) study aimed at characterizing the neural encoding of the fundamental frequency of speech sounds in neonates born at the higher end of the birth weight continuum (>90th percentile), known as large-for-gestational age (LGA). Design: Twenty-five LGA newborns were recruited from...

Objective: The aim of this study was to explore midbrain measurements including corpus callosum-fastigium length and tectal length assessed by neurosonography (NSG) in late-onset small fetuses subclassified into small-for-gestational-age (SGA) or fetal growth restriction (FGR). Methods: This was a case-control study with cases recruited as a coh...

Fetal hearing experiences shape the linguistic and musical preferences of neonates. From the very first moment after birth, newborns prefer their native language, recognize their mother's voice and show a greater responsiveness to lullabies presented during pregnancy. Yet, the neural underpinnings of this experience inducing plasticity have remaine...

The frequency-following response (FFR) to periodic complex sounds is a noninvasive scalp-recorded auditory evoked potential that reflects synchronous phase-locked neural activity to the spectrotemporal components of the acoustic signal along the ascending auditory hierarchy. The FFR has gained recent interest in the fields of audiology and auditory...

In western cultures, when it comes to places of worship and liturgies, music, acoustics and architecture go hand in hand. In the present study, we aimed to investigate whether the emotions evoked by music are enhanced by the acoustics of the space where the music was composed to be played on. We explored whether the emotional responses of western n...

Adaptation to the sensory environment is essential in everyday life, to anticipate future events and quickly detect and respond to changes; and to distinguish vocal variations in congeners, for communication. The aim of the current study was to explore the effects of the nature (vocal/non-vocal) of the information to be encoded, on the establishmen...

Infants born after fetal growth restriction (FGR) –an obstetric condition defined as the failure to achieve the genetic growth potential– are prone to neurodevelopmental delays, with language being one of the major affected areas. Yet, while verbal comprehension and expressive language impairments have been observed in FGR infants, children and eve...

No PDF available ABSTRACT Encoding changes of voice pitch and formant structure plays an important role in speech comprehension since birth. Thus, proper functional assessment in perinatal hospital settings is of essence, but time constraints render the evaluation unfeasible. Here we present a novel two-vowel, rising-pitch-ending stimulus (/oa/; 25...

Electrophysiological sensory deviance detection signals, such as the mismatch negativity (MMN), have been interpreted from the predictive coding framework as manifestations of prediction error (PE). From a frequentist perspective of the classic oddball paradigm, deviant stimuli are unexpected because of their low probability. However, the amount of...

Speech comprehension deficits constitute a major issue for an increasingly aged population, as they may lead older individuals to social isolation. Since conversation requires constant monitoring, updating and selecting information, auditory working memory decline, rather than impoverished hearing acuity, has been suggested a core factor. However,...

Purpose The purpose of this study is to characterize parameters used for frequency-following response (FFR) acquisition in children up to 24 months of age through a systematic review. Method The study was registered in PROSPERO and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses' recommendations. Search was performe...

Does language categorization influence face identification? The present study addressed this question by means of two experiments. First, to establish language categorization of faces, the memory confusion paradigm was used to create two language categories of faces, Spanish and English. Subsequently, participants underwent an oddball paradigm, in...

Detailed neural encoding of voice pitch and formant structure plays a crucial role in speech perception, and is of key importance for an appropriate acquisition of the phonetic repertoire in infants since birth. However, the extent to what newborns are capable of extracting pitch and formant structure information from the temporal envelope and the...

The frequency-following response (FFR) to periodic complex sounds has gained recent interest in auditory cognitive neuroscience as it captures with great fidelity the tracking accuracy of the periodic sound features in the ascending auditory system. Seminal studies suggested the FFR as a correlate of subcortical sound encoding, yet recent studies a...

How important is the influence of spatial acoustics on our mental processes related to sound perception and cognition? There is a large body of research in fields encompassing architecture, musicology, and psychology that analyzes human response, both subjective and objective, to different soundscapes. But what if we want to understand how acoustic...

Introduction The global COVID-19 pandemic has affected the economy, daily life, and mental/physical health. The latter includes the use of electroencephalography (EEG) in clinical practice and research. We report a survey of the impact of COVID-19 on the use of clinical EEG in practice and research in several countries, and the recommendations of a...

The frequency-following response (FFR) is an auditory evoked potential (AEP) that follows the periodic characteristics of a sound. Despite being a widely studied biosignal in auditory neuroscience, the neural underpinnings of the FFR are still unclear. Traditionally, FFR was associated with subcortical activity, but recent evidence suggested cortic...

Auditory prediction errors have been extensively associated with the mismatch negativity (MMN), a cortical auditory evoked potential that denotes deviance detection. Yet, many studies lacked the appropriate controls to disentangle sensory adaptation from prediction error. Furthermore, subcortical deviance detection has been shown in humans through...

Recent research has highlighted atypical reactivity to sensory stimulation as a core symptom in children with autism spectrum disorder (ASD). However, little is known about the dysfunctional neurological mechanisms underlying these aberrant sensitivities. Here we tested the hypothesis that the ability to filter out auditory repeated information is...

Entry on the Encyclopedia of Computational Neuroscience about the Auditory Frequency Following Responses. It includes the following parts: Definition, Introduction to the FFR, Recording the FFR: Technical Considerations, Neural Generators, Developmental Issues: The FFR from Birth to Adulthood, Effects of Experience-Dependent Plasticity on the FFR,...

Entry on the Encylopedia of Computational Neuroscience about the Auditory Brainstem Responses

In electroencephalography (EEG) measurements, processing of periodic sounds in the ascending auditory pathway generates the frequency-following response (FFR) phase-locked to the fundamental frequency (F0) and its harmonics of a sound. We measured FFRs to the steady-state (vowel) part of syllables /ba/ and /aw/ occurring in binaural rapid streams o...

The Oxford Handbook of the Auditory Brainstem provides an in-depth reference to the organization and function of ascending and descending auditory pathways in the mammalian brainstem. Individual chapters are organized along the auditory pathway, beginning with the cochlea and ending with the auditory midbrain. Each chapter provides an introduction...

Perception is a highly active process relying on the continuous formulation of predictive inferences using short-term sensory memory templates, which are recursively adjusted based on new input. According to this idea, earlier studies have shown that novel stimuli preceded by a higher number of repetitions yield greater novelty responses, indexed b...

The Frequency-Following Response (FFR) is a neurophonic auditory evoked potential that reflects the efficient encoding of speech sounds and is disrupted in a range of speech and language disorders. This raises the possibility to use it as a potential biomarker for literacy impairment. However, reference values for comparison with the normal populat...

We present a single-case study on the potential clinical relevance of a new altered auditory feedback (AAF) device (Forbrain®) in stuttering. One adult who stutter was tested in an appropriately-controlled single-case time-series (A-B-A) study. On each of six consecutive working days, the stuttering adult was instructed to read aloud during three d...

Objective: The aging effects on auditory change detection have been studied using the Mismatch Negativity (MMN) potential. However, recent studies have found earlier correlates of deviance detection at the level of the middle-latency response (MLR) and the effects of aging on this deviant-related response have not yet been clarified. The purpose of...

In electrophysiological research, automatic auditory deviance detection has traditionally been associated with mismatch negativity (MMN), a component of the auditory evoked potential (AEP), peaking at 100–250 ms from stimulus onset. However, a series of recent studies have revealed that MMN may no longer represent the earliest electrophysiological...

Purpose: The purpose of this study was to run a proof of concept on a new commercially available device, Forbrain® (Sound For Life Ltd/Soundev, Luxemburg, model UN38.3), to test whether it can modulate the speech of its users. Method: Participants were instructed to read aloud a text of their choice during 3 experimental phases: baseline, test,...

Steroid hormones are important regulators of brain development, physiological function, and behavior. Among them, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS) also do modulate emotional processing and may have mood enhancement effects. This chapter reviews the studies that bear relation to DHEA and DHEAS [DHEA(S)] and br...

Perception is characterized by a reciprocal exchange of predictions and prediction error signals between neural regions. However, the relationship between such sensory mismatch responses and hierarchical predictive processing has not yet been demonstrated at the neuronal level in the auditory pathway. We recorded single-neuron activity from differe...

When two pure tones of slightly different frequencies are delivered simultaneously to the two ears, is generated a beat whose frequency corresponds to the frequency difference between them. That beat is known as acoustic beat. If these two tones are presented one to each ear, they still produce the sensation of the same beat, although no physical c...

Attention capture by potentially relevant environmental stimuli is critical for human survival, yet it varies considerably among individuals. A large series of studies has suggested that attention capture may depend on the cognitive balance between maintenance and manipulation of mental representations and the flexible switch between goal-directed...

Schematic of the task. (TIF)

Phase-Locking Factor (PLF) results. (XLSX)

Topographic plots of the distribution of PLF values across the scalp. PLF values in the eighteen channels analyzed (F3, Fz, F4, FC3, FCz, FC4, C3, Cz, C4, CP3, CPz, CP4, P3, Pz, P4, PO3, POz and PO4) were averaged across individuals in the same genotype group for the Novel and Standard stimulus conditions. (PDF)

Performance results. (XLSX)

How does a listener perceive the auditory world and make sense from the myriad of concurrent sounds in the noisy and complex soundscape impinging our ears as a continuous flow? A major emerging view in cognitive auditory neuroscience is that the auditory system implements a pervasive mechanism by which dynamic auditory input is modeled into neural...

The encoding of temporal regularities is a critical property of the auditory system, as short-term neural representations of environmental statistics serve to auditory object formation and detection of potentially relevant novel stimuli. A putative neural mechanism underlying regularity encoding is repetition suppression, the reduction of neural ac...

Significance statement: The accurate encoding of speech sounds in the subcortical auditory nervous system is of paramount relevance for human communication, and it has been shown to be altered in different disorders of speech and auditory processing. Importantly, this encoding is plastic and can therefore be enhanced by language and music experien...

Several studies have suggested that dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS) may enhance working memory and attention, yet current evidence is still inconclusive. The balance between both forms of the hormone might be crucial regarding the effects that DHEA and DHEAS exert on the central nervous system. To test the h...

Deviance detection is a key functional property of the auditory system that allows pre-attentive discrimination of incoming stimuli not conforming to a rule extracted from the ongoing constant stimulation, thereby proving that regularities in the auditory scene have been encoded in the auditory system. Using simple-feature stimulus deviations, regu...

It is well known that human auditory brain can extract acoustic regularities and detect any deviation from those regularities in the dynamically changing acoustic environment. The mechanism under which the brain can detect deviating stimuli has been a matter of research since the discovery of the Mismatch Negativity (MMN) component of the event-rel...

Detecting unexpected stimuli in the environment is a critical function of the auditory system. Responses to unexpected "deviant" sounds are enhanced compared to responses to expected stimuli. At the human scalp, deviance detection is reflected in the mismatch negativity (MMN) and in an enhancement of the middle-latency response (MLR). Single neuron...

The mismatch negativity (MMN) provides a correlate of automatic auditory discrimination in human auditory cortex that is elicited in response to violation of any acoustic regularity. Recently, deviance-related responses were found at much earlier cortical processing stages as reflected by the middle latency response (MLR) of the auditory evoked pot...

People differ in their ability to perceive second language (L2) sounds. In early bilinguals the variability in learning L2 phonemes stems from speech-specific capabilities (Díaz, Baus, Escera, Costa & Sebastián-Gallés, 2008). The present study addresses whether speech-specific capabilities similarly explain variability in late bilinguals. Event-rel...

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulphate (DHEAS) may have mood enhancement effects: higher DHEAS concentrations and DHEA/cortisol ratio have been related to lower depression scores and controlled trials of DHEA administration have reported significant antidepressant effects. The balance between DHEAS and DHEA has been sugge...

This study aimed to test single and double deviance-related modulations of the middle latency response (MLR) and the applicability of the optimum-2 multi-feature paradigm. The MLR and the MMN to frequency, intensity and double-feature deviants of an optimum-2 multi-feature paradigm and the MMN to double-feature deviants of an oddball paradigm were...

By encoding acoustic regularities present in the environment, the human brain can generate predictions of what is likely to occur next. Recent studies suggest that deviations from encoded regularities are detected within 10 to 50ms after stimulus onset, as indicated by electrophysiological effects in the middle latency response (MLR) range. This is...

Prompt detection of unexpected changes in the sensory environment is critical for survival. In the auditory domain, the occurrence of a rare stimulus triggers a cascade of neurophysiological events spanning over multiple time-scales. Besides the role of the mismatch negativity (MMN), whose cortical generators are located in supratemporal areas, cum...

Los conflictos individuales y grupales alteran las propiedades biológicas, químicas y físicas dando lugar a diferentes circuitos neuronales de normalidad o patología. El entorno en el que vivimos incide en nuestra persona y esta, a su vez, influye en nuestra sociedad. Por lo tanto, en el estudio de la conflictología consideramos muy importante tene...

Neurons within the inferior colliculus are known to reproduce the envelope and frequency contents of sounds with their oscillatory patterns. Interestingly, the fidelity of this representation depends on various factors such as musical training (Parbery-Clark, Strait, Hittner, & Kraus, 2013), the socioeconomic status of the person (Skoe, Krizman, &...

Children with Autism Spectrum Disorders (ASDs) often show atypical sensitivity to auditory stimulation and exhibit difficulties in the processing of auditory information. Regularity encoding is a basic property of the auditory system and any disruption in the low level encoding of acoustic regularities might underlie processing deficits, as observe...

Our auditory system is able to encode acoustic regularity of growing levels of complexity to model and predict incoming events. Recent evidence suggests that early indices of deviance detection in the time range of the middle-latency responses (MLR) precede the mismatch negativity (MMN), a well-established error response associated with deviance de...

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulphate (DHEAS) have been reported to have memory enhancement effects in humans. A neuro-stimulatory action and an anti-cortisol mechanism of action may contribute to that relation. In order to study DHEA, DHEAS and cortisol relations to working memory and distraction, we recorded the electr...

The ability to detect unexpected stimuli in the acoustic environment and determine their behavioral relevance to plan an appropriate reaction is critical for survival. This perspective article brings together several viewpoints and discusses current advances in understanding the mechanisms the auditory system implements to extract relevant informat...

Auditory deviance detection has been related to the mismatch negativity (MMN), a component of the human event-related potentials (ERPs), peaking when an infrequent sound, referred as deviant (DEV) is embedded with repeatedly presented sounds, referred as standards (STD) [1]. MMN represents an indirect marker of auditory sensory memory, as its ampli...

Delta oscillations contribute to the human P300 event-related potential evoked by oddball targets, although it is unclear whether they index contextual novelty (event oddballness, novelty P3, nP3), or target-related processes (event targetness, target P3b). To examine this question, the electroencephalogram (EEG) was recorded during a cued task-swi...

In this account, we attempt to integrate two parallel, but thus far, separate lines of research on auditory novelty detection: (1) human studies of EEG recordings of the mismatch negativity (MMN), and (2) animal studies of single-neuron recordings of stimulus-specific adaptation (SSA). The studies demonstrating the existence of novelty neurons show...

Detection of changes in the acoustic environment is critical for survival, as it prevents missing potentially relevant events outside the focus of attention. In humans, deviance detection based on acoustic regularity encoding has been associated with a brain response derived from the human EEG, the mismatch negativity (MMN) auditory evoked potentia...

This study asks whether early bilingual speakers who have already developed a language control mechanism to handle two languages control a dominant and a late acquired language in the same way as late bilingual speakers. We therefore, compared event-related potentials in a language switching task in two groups of participants switching between a do...

There is recognition that biomedical research into the causes of mental disorders and their treatment needs to adopt new approaches to research. Novel biomedical techniques have advanced our understanding of how the brain develops and is shaped by behaviour and environment. This has led to the advent of stratified medicine, which translates advance...

Auditory deviance detection has been related to the mismatch negativity (MMN), a component of the human event-related potentials (ERPs), peaking when an infrequent sound, referred as deviant (DEV) is embedded with repeatedly presented sounds, referred as standards (STD) [1]. MMN represents an indirect marker of auditory sensory memory, as its ampli...