Biology subjects

Albouy, P.

Publications and source records attributed to Albouy, P..

10 recordsLinked to original sources

bioRxiv2026

Cortical encoding of probabilistic temporal predictions during speech perception

The temporal structure of speech has traditionally been characterized by the rhythmicity of its canonical linguistic units (phonemes, syllables, words), each summarized by a mean occurrence rate. While valid, this view overlooks whether speech carries a finer, context-dependent and probabilistic temporal structure that could support temporal predictive coding during listening. Using large French and English speech corpora, we trained models of increasing complexity to predict the onsets of linguistic units. Recurrent neural networks (RNNs) outperform mean-rate and hazard-rate models, showing that the variability around these rates is not noise but a temporal structure shaped by local context, statistically predictable across phonemes, syllables and words. Recording from 7,698 intracerebral electrodes in 53 neurosurgical patients listening to natural speech, we next show that the models' output), the continuous probability of an upcoming onset (when), explains neural activity beyond acoustic and linguistic content (what) features, with markedly stronger effects for RNNs than for mean- or hazard-rate models. This dynamic neural prediction of when an onset will occur is dissociable from the encoding of linguistic content, relying on largely distinct channel populations. Temporal predictions engage a distributed cortical network extending from bilateral temporal cortex into left frontal and sensorimotor regions. Together, these results establish temporal prediction in speech as a dynamic, context-dependent and probabilistic process in its own right.

neuroscience↗

bioRxiv2026

Cortico-Hippocampal phase-amplitude coupling is a signature of learned audiovisual associations in humans

Phase-Amplitude Coupling (PAC) has been proposed as an elegant neural mechanism for representing sequential items in memory, coordinating distant brain regions, and parsing complex sensory inputs. Yet, whether PAC carries content-specific, behaviorally meaningful information has not been demonstrated to date. Here, using human intracranial recordings before, during and after an audio-visual associative learning task, we show that PAC is an information-coding mechanism. PAC strength in cortico-hippocampal networks increased linearly during learning and remained significantly stronger post vs. pre-learning. More importantly, PAC comodulograms carried stimulus- and association-specific information: auditory items were decodable in auditory cortex before learning based on PAC features, while learned associations were classified across hippocampo-temporo-frontal networks during and after learning. Post-learning brain decoding confusion matrices closely mirrored behavioral confusion matrices, and PAC patterns were independent of low-level stimulus features. These findings suggest that PAC is an endogenously generated marker that supports perception and associative learning in the human brain. One-sentence summaryWe demonstrate that phase-amplitude coupling (PAC) in cortico-hippocampal networks serves as a specific, endogenously generated, and behaviorally meaningful neurophysiological mechanism for perceiving, learning, and maintaining audio-visual associations.

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bioRxiv2025

Sleep after Motor Sequence Learning Enhances Post-Movement Parietal Beta Synchronization

The neural substrates supporting the beneficial effect of sleep on motor memory consolidation are well described. However, less is known about the brain oscillatory dynamics underlying these processes. We characterized the oscillatory dynamics associated with motor sequence learning and their modulation by post-learning sleep using magnetoencephalography (MEG) in young healthy adults. After learning a motor sequence task while their brain activity was recorded with MEG, participants were distributed in two groups according to whether they slept or were totally sleep deprived during the first post-training night. Consolidation was assessed with a retest in the MEG three days after training. Behaviorally, performance improved over the consolidation interval irrespective of whether sleep was afforded during the first night. MEG results showed that initial motor sequence learning was characterized by a progressive decrease in beta Event Related Desynchronization (ERD, 18-25Hz) over bilateral motor areas. Interestingly, while these practice-related modulations of beta ERD were not influenced by the sleep status, post-learned-movement beta Event Related Synchronization (ERS) over bilateral parietal areas increased over the consolidation interval in the sleep, compared to the sleep deprived, group. These results extend current models of motor memory consolidation by identifying ERS as an oscillatory marker of sleep-dependent consolidation.

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bioRxiv2025

Mu suppression reveals auditory-motor predictions after short motor training in non-musicians

Auditory-motor coupling is a bidirectional neural mechanism that supports speech and music, with evidence of motor system activation during passive listening to both spoken language and learned melodies. Such activation is anticipatory, occurs in non-musicians, and can be elicited at the single-note level. These findings support the idea that motor activity guides auditory perception by relaying predictive timing information. However, the neural processes underlying this activity are not fully understood. EEG studies in musicians have linked it to mu-band suppression, but the temporal scale and the generalizability to the broader population remain unclear. We recruited 25 non-musicians who learned to play a simple melody on a piano-like keyboard. Before and after training, participants passively listened to the trained melody and control melodies. Offline, EEG data from the motor training were used to create a time-frequency mask with which to identify mu suppression occurring during passive listening. Significant mu suppression emerged before each note only during post-training exposure to the practiced melody. Results suggest that mu suppression occurs at the single-note level following short motor training and is not dependent on prior musical experience. Our findings support the notion that motor activity aids perception by anticipating the unfolding of learned auditory-motor sequences.

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bioRxiv2025

Neural coding of spectrotemporal modulations in the auditory cortex supports speech and music categorization

Auditory processing is typically described as hierarchical, culminating in neural representation of abstract categories. However, it remains unclear whether category-selective responses in auditory cortex require representational mechanisms beyond the coding of acoustic features, or whether the acoustic representations already available in the auditory cortex are sufficient to account for categorization. Here, we test whether cortical coding of spectrotemporal modulation (STM) features is sufficient to support speech-music categorization by combining human intracranial recordings with continuous behavioral judgments of a naturalistic soundtrack in which speech and music occur both separately and simultaneously. We show that temporal and spectral modulation patterns largely characterize speech and music, respectively, and that cortical auditory regions robustly track these features over time, with distinct oscillatory frequency bands preferentially encoding temporal and spectral modulations. Critically, cortical representations of STMs predicted perceptual categorical judgments gathered in an independent sample. Finally, speech- and music-related STM representations showed stronger tracking of category-specific acoustical features in left versus right cortical auditory regions, respectively. These findings indicate that the efficient neural coding of acoustical features provides a sufficient basis for the categorical distinction between speech and music, and that the temporal and spectral components of this representation are implemented through distinct oscillatory mechanisms.

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bioRxiv2025

Valence-dependent sensory-rhythmic neural entrainment modulates cortico-subcortical dynamics, attention, and memory

Sensory rhythmic stimulation enhances executive functions by entraining oscillations in higher- order cortical networks, but its effects on subcortical structures remain unclear. We propose that stimulus valence is a key feature to enable subcortical entrainment. Using intracranial EEG in epileptic patients, we first show that visual search is supported by cortico-subcortical theta (5Hz) activity. We then show that 5 Hz negative-valence visual stimulation entrains theta oscillations in a task-related network, including the ventral visual stream, hippocampus, and dorsolateral prefrontal cortex. Finally, in a behavioral experiment in healthy individuals, we show that both neutral and negative valence 5 Hz stimulation improved visual search speed, but only negative valence stimulation enhanced target image recognition as assessed through an additional memory task. These findings highlight the role of stimulus valence in modulating subcortical brain activity and behaviors through rhythmic sensory stimulation and pave the way for further applications in clinical intervention.

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bioRxiv2024

Spatiotemporal patterns of theta-band activity during rapid-eye movement sleep: a magnetoencephalography analysis

Theta oscillations (4-8 Hz) in frontal cortical regions are present to different degrees across states of consciousness. In sleep, theta is prominent in periods of rapid eye-movement (REM) sleep. Theta has been linked to processes of memory consolidation; however, its mechanistic contribution specifically during REM sleep is not well understood. Interestingly, in the wake state, frontal theta activity increases during effortful cognitive tasks involving executive functions such as working memory, hinting at similarities in circuitry, and potentially, function. The aim of the present work is to create a spatially resolved, whole-brain characterisation of REM oscillatory activity in healthy human subjects, distinguishing theta from neighbouring frequency bands, differentiating substages of REM sleep (phasic and tonic REM), and comparing REM theta to that which is evoked during a working memory task. To that end, we analysed magneto- and electroencephalography (M/EEG) data recorded during overnight sleep in 10 healthy subjects, and similar data from 17 healthy subjects who performed a working memory task, using a novel whole-brain, source-localised MEG approach. Our results show that (i) theta activity has a frontal midline topography that is distinct from those of other prominent frequency bands in REM (delta, alpha, beta), (ii) theta activity in frontal midline regions is best observed within a focused 5-7 Hz range, separating it from occipital alpha activity, (iii) REM theta is dominant over the frontal midline but is also observed in several sub-cortical areas, (iv) theta is more widespread in tonic than phasic REM sleep, and (v) the focused frontal midline theta pattern observed in REM phasic sleep is the most similar of all observed sleep substages to theta evoked by a working memory task. These results enhance our understanding of theta physiology in REM sleep and suggest future targets for research into REMs role in learning and memory.

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bioRxiv2024

Information-based rhythmic transcranial magnetic stimulation accelerates learning during auditory working memory training.

Rhythmic transcranial magnetic stimulation (rhTMS) has been shown to enhance auditory working memory manipulation, specifically by boosting theta oscillatory power in the dorsal auditory pathway during task performance. It remains unclear whether these enhancements i) persist beyond the period of stimulation, ii) if they can accelerate learning and iii) if they would accumulate over several days of stimulation. In the present study, we investigated the lasting behavioural and electrophysiological effects of applying rhTMS over the left intraparietal sulcus (IPS) throughout the course of seven sessions of cognitive training on an auditory working memory task. Fourteen neurologically healthy participants took part in the training protocol with an auditory working memory task while being stimulated with either theta (5Hz) rhTMS or sham TMS. Electroencephalography (EEG) was recorded before, throughout five training sessions and after the end of training to assess to effects of rhTMS on behavioural performance and on oscillatory entrainment of the dorsal auditory network. We show that this combined approach enhances theta oscillatory activity within the fronto-parietal network and causes improvements in auditory working memory performance. We show that compared to individuals who received sham stimulation, cognitive training can be accelerated when combined with optimized rhTMS, and that task performance benefits can outlast the training period by up to 3 days. Furthermore, we show that there is increased theta oscillatory power within the recruited dorsal auditory network during training, and that sustained EEG changes can be observed up to 3 days following stimulation. The present study improves our understanding of the causal dynamic interactions supporting auditory working memory. Our results constitute an important proof of concept for the potential translational impact of non-invasive brain stimulation protocols and provide preliminary data for developing optimized rhTMS and training protocols that could be implemented in clinical populations.

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bioRxiv2023

Spectro-temporal acoustical markers differentiate speech from song across cultures

Humans produce two forms of cognitively complex vocalizations: speech and song. It is debated whether these differ based primarily on culturally specific, learned features, or if acoustical features can reliably distinguish them. We study the spectro-temporal modulation patterns of vocalizations produced by 369 people living in 21 urban, rural, and small-scale societies across six continents. Specific ranges of spectral and temporal modulations, overlapping within categories and across societies, significantly differentiate speech from song. Machine-learning classification shows that this effect is cross-culturally robust, vocalizations being reliably classified solely from their spectro-temporal features across all 21 societies. Listeners unfamiliar with the cultures classify these vocalizations using similar spectro-temporal cues as the machine learning algorithm. Finally, spectro-temporal features are better able to discriminate song from speech than a broad range of other acoustical variables, suggesting that spectro-temporal modulation--a key feature of auditory neuronal tuning--accounts for a fundamental difference between these categories. Two-Sentence SummaryWhat distinguishes singing from speaking? The authors show that consistent acoustical spectro-temporal features are sufficient to distinguish speech and song reliably across different societies throughout the world.

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bioRxiv2020

Neurophysiological network dynamics of pitch change detection.

The detection of pitch changes is crucial to sound localization, music appreciation and speech comprehension, yet the brain network oscillatory dynamics involved remain unclear. We used time-resolved cortical imaging in a pitch change detection task. Tone sequences were presented to both typical listeners and participants affected with congenital amusia, as a model of altered pitch change perception. Our data show that tone sequences entrained slow (2-4 Hz) oscillations in the auditory cortex and inferior frontal gyrus, at the pace of tone presentations. Inter-regional signaling at this slow pace was directed from auditory cortex towards the inferior frontal gyrus and motor cortex. Bursts of faster (15-35Hz) oscillations were also generated in these regions, with directed influence from the motor cortex. These faster components occurred precisely at the expected latencies of each tone in a sequence, yielding a form of local phase-amplitude coupling with slower concurrent activity. The intensity of this coupling peaked dynamically at the moment of anticipated pitch changes. We clarify the mechanistic relevance of these observations in relation to behavior as, by task design, typical listeners outperformed amusic participants. Compared to typical listeners, inter-regional slow signaling toward motor and inferior frontal cortices was depressed in amusia. Also, the auditory cortex of amusic participants over-expressed tonic, fast-slow phase-amplitude coupling, pointing at a possible misalignment between stimulus encoding and internal predictive signaling. Our study provides novel insight into the functional architecture of polyrhythmic brain activity in auditory perception and emphasizes active, network processes involving the motor system in sensory integration.

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