Biology subjects

Molinaro, N.

Publications and source records attributed to Molinaro, N..

At least 19 recordsLinked to original sources

bioRxiv2026

The interplay between cortical tracking and functional connectivity in musicians and non-musicians listening to speech and music

Musical expertise is associated with auditory processing advantages which can extend to the speech domain. However, the origins of such domain-general benefits remain unclear. Recent frameworks propose that better rhythm processing in musicians might be at the basis of the observed advantages in processing music and speech. Auditory cortical tracking and inter-regional interactions between auditory and motor areas have been proposed as key neural mechanisms. In this study, we asked whether expertise-related increase in cortical tracking would be elicited by naturalistic stimuli in clear listening conditions, and whether such effects would be related to audiomotor functional connectivity and individual rhythmic abilities. We compared MEG data from expert musicians and controls with no musical playing experience while they listened to two-minutes long stories and excerpts of piano music. We also collected behavioral data in a rhythmic task testing speech (syllable) production. We found that musicians showed enhanced tracking and enhanced functional connectivity in both speech and music conditions, as well as better rhythmic abilities relative to non-musicians. Alpha connectivity between the right auditory cortex and inferior frontal gyrus negatively predicted cortical tracking across all participants in the speech condition, while no relation was observed for music. We suggest that stronger cortical tracking in musicians is due to domain-general differences in auditory sensory processes and is not driven by motor influences in our experiment. Moreover, a trade-off between cortical tracking and inter-regional communication might be at the basis of optimal perception of speech in both musicians and non-musicians in clear listening conditions.

neuroscience↗

bioRxiv2026

The cortex encodes speech timing as departure from expectation, not as physical measurement

Every syllable and every phoneme in natural speech has a different duration. This variability is conventionally treated as jitter, noise the brain must overcome to recover an underlying regularity. Here we show that the cortex encodes it as information. We recorded magnetoencephalography from 25 native listeners of Spanish during twenty minutes of spontaneous narrative speech in Spanish, a syllable-timed language in which durational variability is low, making it a conservative test case. We modelled cortical activity with three timing regressors defined at successively finer grains: deviation from the expected syllabic beat, from the expected phoneme onset, and from the expected duration of the phoneme just completed. Fitted jointly, and against acoustic and linguistic-surprisal baselines, each regressor explained unique activity in bilateral superior temporal cortex, with distinct response latencies spanning 70 to 250 ms. The duration regressor explained cortical activity beyond raw phoneme duration, whereas raw duration explained no additional variance once it was included. At the onset grain, by contrast, predicted and physical timing contributed jointly. The onset departure was encoded with its sign, distinguishing events that arrived early from those that arrived late. In a separate sample, removing this durational variability was costly: comprehension in noise degraded under imposed isochrony relative to natural timing. Durational variability is therefore not noise the cortex discards but information it encodes, across a hierarchy of timescales - and at the finest grain, what is encoded is not how long a speech event lasted but how far its duration departed from expectation.

neuroscience↗

bioRxiv2026

Low-frequency neural responses synchronize to distinct structural rather than lexical features during sentence comprehension

Language comprehension involves the integration of single words (lexical units) into phrases and sentences (multi-word structures). Previous frequency-tagging studies have found that low-frequency neural responses synchronize to the frequency of multi-word structures. However, it is currently unclear how exactly structural and lexical processes jointly impact these synchronization findings. The present magnetoencephalography experiment implemented the frequency-tagging paradigm in the visual modality with written words to investigate neural synchronization to multi-word sentences varying in internal structure (reversed word orders between verb-initial Spanish and verb-final Basque sentences) and in lexical content (real words and pseudo words). We find converging evidence that neural responses largely synchronize to structural rather than lexical features. This was observed as robust phase synchronization strength to the frequency of sentences containing reversed structures, with certain lexical modulations depending on language-specific structural features. Crucially, we also found shifted phase angle dynamics between the reversed structures of Spanish and Basque sentences independently of word-level lexical characteristics. Together, these findings suggest that neural synchronization to multi-word structures is largely driven by distinct structural features operating via two segregated neural dimensions: frequency coding for the coarser aspects (i.e., timescale/duration) and phase representing the finer-grained aspects (i.e., internal structure) of multi-word structures. Our findings thus advance key insights into the core components of the neural mechanisms supporting language comprehension. HighlightsO_LINeural synchronization to sentences is driven by structural (not lexical) features. C_LIO_LIRobust sentence-frequency synchronization across languages varying in structure. C_LIO_LIPhase angle is selectively sensitive to cross-linguistic structural differences. C_LIO_LILexical modulations depend on language-specific structure. C_LIO_LIStructure synchronization segregates into two dimensions: frequency and phase. C_LI

neuroscience↗

bioRxiv2026

Modulating Neural Tracking of Speech in Infants

Neural oscillations synchronize to the rhythmic structure of speech, a process known as cortical tracking that is thought to support speech perception and language acquisition. Individual differences in cortical tracking during infancy predict later language outcomes, yet little is known about whether this neural mechanism can be shaped by recent auditory experience early in development. Here, we tested whether brief exposure to structured musical rhythms modulates cortical tracking of speech in Spanish-Basque bilingual infants at 6 and 10 months of age. Infants listened to speech preceded by either temporally regular musical sequences that mirrored the rhythmic structure of the speech signal or rhythmically irregular musical sequences. Cortical tracking was measured using electroencephalography and quantified as speech-brain coherence in the delta and theta frequency bands. Regular musical sequences enhanced subsequent cortical tracking of speech, but the effects varied across age, language, and frequency band. In Spanish, rhythmic priming enhanced delta-band tracking at 10 months of age, whereas in Basque it enhanced theta-band tracking at both 6 and 10 months. These language-specific effects suggest that rhythmic priming interacts with the temporal properties of individual languages and infants developing linguistic experience. Together, the findings demonstrate that cortical tracking is a highly flexible neural mechanism during infancy and can be rapidly modulated by structured rhythmic input. Thus, we identify rhythmic experience as a potential pathway through which infants auditory environment shapes neural speech processing during language development.

neuroscience↗

bioRxiv2026

Bridging the neural synchronization to linguistic structures and natural speech comprehension

Speech comprehension involves the inference of abstract information from continuous acoustic signals. Prior work suggests that electrophysiological activity is synchronized with abstract linguistic structures (phrases and sentences) during the processing of isochronous syllable sequences. It is yet unclear whether this prior evidence generalizes to natural speech comprehension, which requires the flexible processing of continuous speech, where syllables and other types of linguistic units are anisochronous. Our magnetoencephalography experiment investigated neural synchronization to acoustic (syllables) and abstract units (phrases and sentences) using continuous speech ranging from artificial isochronous to more natural anisochronous. We find that neural synchronization to phrases and sentences, but not syllables, is resilient to naturalistic anisochrony. This suggests that linguistic structure processing reflects endogenous inferences that are fundamentally distinct from the exogenous processing of syllables driven by speech acoustics. Lateralization and linear regression results extend this functional dissociation as hemispheric asymmetry: stimulus-independent leftward lateralization for linguistic structure processing but stimulus-driven rightward lateralization (or bilaterality) for both syllable and acoustic processing. Our findings provide a more realistic characterization of the flexible neural mechanisms supporting the efficient comprehension of natural speech.

neuroscience↗

bioRxiv2024

Temporal Structure of Music Improves the Cortical Encoding of Speech

Long and short-term musical training has been proposed to improve efficiency of cortical tracking of speech, the mechanism through which brain oscillations synchronize to the acoustic temporal structure of external stimuli. Here, we study how different rhythm structures of the musical signal can guide the temporal dynamics of auditory oscillations phase-aligned to the speech envelope. For this purpose, we investigated the effects of prior exposure to rhythmically structured musical sequences on cortical tracking of speech in Basque-Spanish bilingual adults. We conducted two EEG experiments where participants were presented with sentences in Basque and Spanish preceded by musical sequences that differed in their beat structure. The beat structure of the musical sequences was created to 1) reflect and match the syllabic structure of the sentences, 2) reflect a regular rhythm but not match the syllabic structure of the sentences, and 3) follow an irregular rhythm. First, we showed that the regularity found in the rhythmic structure of music acts as a temporal guide for brain oscillations. Second, our findings suggest that not only the regularity in music is crucial but so is adjusting this regularity to optimally reflect the rhythmic characteristics of the language. Third, despite finding some differences across frequencies for each language, we still found a strong effect of rhythm regularity on cortical tracking of speech. We showed that rhythm, inherent in musical signals, guides the adaptation of brain oscillations, by adapting the temporal dynamics of the oscillatory activity to the rhythmic scaffolding of the musical signal.

neuroscience↗

bioRxiv2024

Cortical tracking of speech is reduced in adults who stutter when listening for speaking

PurposeInvestigate cortical tracking of speech (CTS) in adults who stutter (AWS) compared to typically fluent adults (TFA) to test the involvement of the speech-motor network in tracking auditory information. MethodParticipants EEG was recorded while they either had to simply listen to sentences (listening only) or complete them by naming a picture (listening-for-speaking), thus manipulating the upcoming involvement of speech production. We analyzed speech-brain coherence and brain connectivity during listening. ResultsDuring the listening-for-speaking task, AWS exhibited reduced CTS in the 3-5 Hz range (theta), corresponding to the syllabic rhythm. The effect was localized in left inferior parietal and right pre-/supplementary motor regions. Connectivity analyses revealed that TFA had stronger information transfer in the theta range in both tasks in fronto-temporo-parietal regions. When considering the whole sample of participants, increased connectivity from the right superior temporal cortex to the left sensorimotor cortex was correlated with faster naming times in the listening-for-speaking task. ConclusionsAtypical speech-motor functioning in stuttering also impacts speech perception, especially in situations requiring articulatory alertness. The involvement of frontal and (pre-) motor regions in CTS in typically fluent adults is highlighted. Speech perception in individuals with speech-motor deficits should be further investigated, especially when smooth transitioning between listening and speaking is required, such as in real-life conversational settings.

neuroscience↗

bioRxiv2023

Non-verbal skills in auditory word processing: Implications for typical and dyslexic readers

Dyslexia is characterized by poor phonological skills and atypical neural responses to text and speech stimuli, while non-verbal intelligence remains unaffected. However, the impact of non-verbal intelligence on language-evoked neural responses in dyslexia is underexplored. This study examines non-verbal intelligences effects on neural responses to auditory words in typical and dyslexic readers. Participants completed IQ tests, reading and phonological assessments, and underwent magnetoencephalography recordings while listening to words. Event-related brain field responses at different stages of auditory word processing (100ms, 200ms, 400ms) were analyzed in relation to non-verbal IQ scores and reading performance. Higher non-verbal IQ in typical readers yielded earlier right hemisphere perceptual responses (100ms). Dyslexic readers showed no IQ-related latency effects but those with lower non-verbal IQ displayed amplified left hemisphere response amplitudes at 100ms. These findings confirm the link between non-verbal cognitive abilities and early auditory word processing in adults, highlighting distinct effects in dyslexia and controls.

neuroscience↗

bioRxiv2023

The contribution of early language exposure to the cortical tracking of speech

Cortical tracking of speech is relevant for the development of speech perception skills. However, no study to date has explored whether and how cortical tracking of speech is shaped by accumulated language experience, the central question of this study. In 35 bilingual children (6 y.o.) with considerably bigger experience in one language, we collected electroencephalography data while they listened to continuous speech in their two languages. Cortical tracking of speech was assessed at acoustic-temporal and lexico-semantic levels. Children showed more robust acoustic-temporal tracking in the least experienced language, and more sensitive cortical tracking of semantic information in the most experienced language. Additionally, and only for the most experienced language, acoustic-temporal tracking was specifically linked to phonological abilities, and lexico-semantic tracking to vocabulary knowledge. Our results indicate that accumulated linguistic experience is a relevant maturational factor for the cortical tracking of speech at different levels during early language acquisition.

neuroscience↗

bioRxiv2023

Language experience shapes predictive coding of rhythmic sound sequences

Perceptual systems heavily rely on prior knowledge and predictions to make sense of the environment. Predictions can originate from multiple sources of information, including contextual short-term priors, based on isolated temporal situations, and context-independent long-term priors, arising from extended exposure to statistical regularities. While the effects of short-term predictions on auditory perception have been well-documented, how long-term predictions shape early auditory processing is poorly understood. To address this, we recorded magnetoencephalography data from native speakers of two languages with different word orders (Spanish: functor-initial versus Basque: functor-final) listening to simple sequences of binary sounds alternating in duration with occasional omissions. We hypothesized that, together with contextual transition probabilities, the auditory system uses the characteristic prosodic cues (duration) associated with the native languages word order as an internal model to generate long-term predictions about incoming non-linguistic sounds. Consistent with our hypothesis, we found that the amplitude of the mismatch negativity elicited by sound omissions varied orthogonally depending on the speakers linguistic background and was most pronounced in the left auditory cortex. Importantly, listening to binary sounds alternating in pitch instead of duration did not yield group differences, confirming that the above results were driven by the hypothesized long-term "duration" prior. These findings show that experience with a given language can shape a fundamental aspect of human perception - the neural processing of rhythmic sounds - and provides direct evidence for a long-term predictive coding system in the auditory cortex that uses auditory schemes learned over a lifetime to process incoming sound sequences.

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bioRxiv2023

Early language dissociation in the bilingual mind: Sensor-level MEG evidence

Is language selection in balanced bilinguals decodable from neural activity? Previous research employing various neuroimaging methods has not yielded a conclusive answer to this issue. However, direct brain stimulation studies in bilinguals have detected different brain regions related to language production in separate languages. In the present MEG study, we addressed this question in a group of proficient Spanish-Basque bilinguals (N=45), who performed two tasks (picture naming and word reading). They were asked to name the line drawing or read the word out loud, either in Basque or Spanish, if the ink turned from black to green after one second (randomly, in 10% of trials). Sensor-level evoked activity was similar and could not be differentiated for the two languages in either task. Crucially however, decoding analyses classified the language used in both tasks, starting [~]100 ms after stimulus onset. Searchlight analyses revealed that activity detected in the right occipital-temporal sensors contributed the most to language decoding in the picture naming task, while the left occipital-temporal sensors contributed the most to decoding in word reading. The cross-task decoding analysis highlighted robust generalization effects from the picture naming to the word reading task in a later time interval. The present findings bridge the gap between non-invasive and invasive experimental evidence on bilingual lexical processing and provide novel evidence about the role of the two hemispheres in activating each language for picture naming and word reading.

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bioRxiv2022

Decoding Numeracy and Literacy in the Human Brain: Insights from MEG and MVPA

Numbers and letters are the fundamental building blocks of our everyday social interactions. Previous studies have focused on determining the cortical networks shaped by numeracy and literacy in the human brain, partially supporting the hypothesis of distinct neural circuits involved the processing of the two categories. In this study, we aim to investigate the temporal dynamics for number and letter processing. We present MEG data from two experiments (N=20 each). In the first experiment, single numbers, letter, and their respective false fonts (false numbers and false letters) were presented, whereas, in the second experiment, numbers, letters, and their respective false fonts were presented as a string of characters. We used multivariate pattern analysis techniques (time-resolved decoding and temporal generalization) testing the strong hypothesis that the neural mechanisms supporting letter and number processing can be logistically classified as categorically separate. Our results show a very early dissociation ([~]100 ms) between numbers, and letters when compared to false fonts. Number processing can be dissociated with similar accuracy when presented as isolated items or strings of characters, while letter processing shows dissociable classification accuracy for single items compared to strings. These findings reinforce the evidence indicating that early visual processing can be differently shaped by the experience with numbers and letters; this dissociation is stronger for strings compared to single items, thus showing that combinatorial mechanisms for numbers and letters could be categorically distinguished and influence early brain activity.

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bioRxiv2022

Neurodevelopmental oscillatory basis of speech processing in noise

Humans extraordinary ability to understand speech in noise relies on multiple processes that develop with age. Using magnetoencephalography (MEG), we characterize the underlying neuromaturational basis by quantifying how cortical oscillations in 144 participants (aged 5 to 27 years) track phrasal and syllabic structures in connected speech mixed with different types of noise. While the extraction of prosodic cues from clear speech was stable during development, its maintenance in a multi-talker background matured rapidly up to age 9 and was associated with speech comprehension. Furthermore, while the extraction of subtler information provided by syllables matured at age 9, its maintenance in noisy backgrounds progressively matured until adulthood. Altogether, these results highlight distinct behaviorally relevant maturational trajectories for the neuronal signatures of speech perception. In accordance with grain-size proposals, neuromaturational milestones are reached increasingly late for linguistic units of decreasing size, with further delays incurred by noise. TeaserThe neural signature of speech processing in silence and noise features multiple behaviorally relevant developmental milestones

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bioRxiv2021

Alpha and beta rhythms differentially support the effect of symbols on visual object recognition

Hearing spoken words can enhance visual object recognition, detection and discrimination. Yet, the mechanisms that underpin this facilitation are incompletely understood. On one account, words do not bias early visual processing, but rather affect later semantic or decision-making stages. However, recent proposals suggest that words can alter early visual processes by activating category-specific priors in sensory regions. A prediction of this account is that top-down priors evoke changes in occipital areas in anticipation of visual stimuli. Here, we tested the hypothesis that neural oscillations serve as a mechanism to activate language-generated visual priors. Participants performed a cue-picture matching task where cues were either spoken words, in their native or second language, or natural sounds, while their EEG and reaction times were recorded. Behaviorally, we replicated the previously reported label-advantage effect, with images cued by words being recognized faster than those cued by natural sounds. A time-frequency analysis of cue-target intervals revealed that this behavioral label-advantage was associated with enhanced power in posterior alpha (9-11 Hz) and beta oscillations (17-19 Hz), both of which were larger when the image was preceded by a word compared to a natural sound. Importantly, object recognition performance improved with high alpha power but slowed down with enhancement of beta synchronization. These results suggest that alpha and beta rhythms play distinct functional roles to support language-mediated visual object recognition: alpha might function to amplify sensory priors in posterior regions, while beta may (re)activate the network states elicited by the auditory cue.

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bioRxiv2021

Reading-related brain changes in audiovisual processing: cross-sectional and longitudinal MEG evidence

The ability to establish associations between visual objects and speech sounds is essential for human reading. Understanding the neural adjustments required for acquisition of these arbitrary audiovisual associations can shed light on fundamental reading mechanisms and help reveal how literacy builds on pre-existing brain circuits. To address these questions, the present longitudinal and cross-sectional MEG studies characterize the temporal and spatial neural correlates of audiovisual syllable congruency in children (4-9 years old, 22 males and 20 females) learning to read. Both studies showed that during the first years of reading instruction children gradually set up audiovisual correspondences between letters and speech sounds, which can be detected within the first 400 ms of a bimodal presentation and recruit the superior portions of the left temporal cortex. These findings suggest that children progressively change the way they treat audiovisual syllables as a function of their reading experience. This reading-specific brain plasticity implies (partial) recruitment of pre-existing brain circuits for audiovisual analysis. Significance StatementLinking visual and auditory linguistic representations is the basis for the development of efficient reading, while dysfunctional audiovisual letter processing predicts future reading disorders. Our developmental MEG project included a longitudinal and a cross-sectional study; both studies showed that childrens audiovisual brain circuits progressively change as a function of reading experience. They also revealed an exceptional degree of neuroplasticity in audiovisual neural networks, showing that as children develop literacy, the brain progressively adapts so as to better detect new correspondences between letters and speech sounds.

neuroscience↗

bioRxiv2021

Temporal Dynamics of Neural Processing of Facial Expressions and Emotions

Emotion processing has been a focus of research in psychology and neuroscience for some decades. While the evoked neural markers in human brain activations in response to different emotions have been reported, the temporal dynamics of emotion processing has received less attention. Differences in processing speeds, that depend on emotion type, have not been determined. Furthermore, behavioral studies have found that the right side of the human face expresses emotions more accurately than the left side. Therefore, accounting for both the content of the emotion and the visual angle of presentation from the perspective of the viewer, here we have investigated variability in the discrimination of happy and sad faces when the visual angle of presentation was Positive (right side of the face) compared to Negative (left side of the face). Furthermore, the temporal dynamics involved in processing happy and sad emotions have been compared. Regardless of visual angle, happy emotions were processed faster than sad emotions. However, the evoked response to sad emotions significantly increased in amplitude compared to that for happy emotions, when faces were presented at Positive visual angles only. Source reconstruction from sensor-level ERFs show localized activities in ventral and dorsal stream, including fusiform gyrus, lingual gyrus, putamen and Pre and Post central gyrus. Multivariate pattern analysis (MVPA) confirmed these findings - demonstrating successful decoding of happy and sad emotions only occurred when the facial expression was viewed from a positive visual angle, and that happy emotions were processed faster than sad emotions.

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bioRxiv2021

Real-Time EEG Neurofeedback as a Tool to Improve Neural Entrainment to Speech

Neurofeedback represents a particular type of biofeedback whose aim is to teach self-control of brain function by measuring brain activity and presenting a feedback signal in real-time. Traditionally, neurofeedback has been used to complement interventions for various neuropsychological disorders through techniques like frequency training, which attempts to change the power ratio of certain EEG frequency bands. However, to date, there are no neurofeedback approaches that look directly into modulating the neural entrainment to speech. Speech-brain entrainment, which stands for the alignment of the neural activity to the envelope of the speech input, has been shown to be key to speech comprehension. In fact, atypical neural entrainment to speech seems to be consistently found in language development disorders such as dyslexia. Thus, making speech entrainment neurofeedback a promising technique to obtain behavioral improvements. In this work, we present the first open-source brain-computer interface system that can be reliably used to provide speech entrainment neurofeedback while still being flexible enough to deliver more traditional coherence-based neurofeedback. In addition, it has the potential of being an open-source alternative to deliver other types of neurofeedback if configured to do so.

bioengineering↗

bioRxiv2020

Temporal uncertainty affects the visual processing of predicted stimulus properties

Predictive processing has been proposed as a fundamental cognitive mechanism to account for how the brain interacts with the external environment via its sensory systems. In vision, contextual information triggers predictions about the content ("what") of environmental stimuli to update an internal generative model of the surrounding world. However, visual information dynamically changes across time, and temporal predictability ("when") may influence the impact of internal predictions on visual processing. In this magnetoencephalography (MEG) study, we investigated how processing feature specific information ("what") is affected by temporal predictability ("when"). In line with previous findings, we observed suppression of evoked neural responses in the visual cortex for predictable stimuli. Interestingly, we found that temporal uncertainty increased expectation suppression. This suggests that in temporally uncertain scenarios the neurocognitive system invests less resources in integrating bottom-up information. Multivariate pattern analysis showed that predictable visual features could be decoded from neural responses. Temporal uncertainty did not affect decoding accuracy for early visual responses, with the feature specificity of early visual neural activity preserved across conditions. However, decoding accuracy was less sustained over time for temporally jittered than for isochronous predictable visual stimuli. These findings converge to suggest that the cognitive system processes visual features of temporally predictable stimuli in higher detail, while processing temporally uncertain stimuli may rely more heavily on abstract internal expectations.

neuroscience↗