Language and the left hemisphere

Elsevier eBooks, Journal Year: 2024, Volume and Issue: unknown, P. 129 - 165

Published: Jan. 1, 2024

Language: Английский

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Hemispheric Asymmetry of Intracortical Myelin Orientation in the Mouse Auditory Cortex

European Journal of Neuroscience, Journal Year: 2025, Volume and Issue: 61(2)

Published: Jan. 1, 2025

ABSTRACT Communication sound processing in mouse AC is lateralized. Both left and right are highly specialised differ auditory stimulus representation, functional connectivity field topography. Previous studies have highlighted intracortical circuits that explain hemispheric preference. However, the underlying microstructure remains poorly understood. In this study, we examine structural lateralization of on basis immunohistochemically stained tissue‐cleared adult brains ( n = 11). We found asymmetries myelination, most prominently layer 2/3, which featured more intercolumnar connections AC. Furthermore, a larger asymmetry also investigated sex differences. male mice, myelination direction tilted to anterior side. This pattern inverted female mice. spatial distribution neuronal cell bodies along laminar axis cortex was remarkably symmetric all samples. These results suggest basic developmentally defined structures such as cortical columns remain untouched by lateral specialisation, but plastic myelinated axons show diverse asymmetries. may contribute specialisation lateralized tasks vocal communication or spectral temporal complexity stimuli.

Language: Английский

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Phenotypic analysis of multielectrode array EEG biomarkers in developing and adult male Fmr1 KO mice

Neurobiology of Disease, Journal Year: 2024, Volume and Issue: 195, P. 106496 - 106496

Published: April 4, 2024

Fragile X Syndrome (FXS) is a leading known genetic cause of intellectual disability with symptoms that include increased anxiety and social sensory processing deficits. Recent electroencephalographic (EEG) studies in humans FXS have identified neural oscillation deficits resting state gamma power, amplitude auditory evoked potentials, reduced phase locking sound-evoked oscillations. Similar EEG phenotypes are present mouse models FXS, but very little about the development such abnormal responses. In current study, we employed 30-channel multielectrode array (MEA) system to record analyze stimulus-evoked signals male P21 P91 WT Fmr1 KO mice. This led several novel findings. First, P91, not P21, mice significantly power low- high-gamma frequency bands. Second, both markedly attenuated inter-trial coherence (ITPC) spectrotemporally dynamic stimuli as well 40 Hz 80 steady-state response (ASSR) stimuli. suggests temporal from early may lead speech language function FXS. Third, found hemispheric asymmetry fast cortex Together, these findings define set young adult can serve translational targets for pharmacological manipulation phenotypic rescue studies.

Language: Английский

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Age-related neural changes underlying long-term recognition of musical sequences

Communications Biology, Journal Year: 2024, Volume and Issue: 7(1)

Published: Aug. 29, 2024

Aging is often associated with decline in brain processing power and neural predictive capabilities. To challenge this notion, we used magnetoencephalography (MEG) magnetic resonance imaging (MRI) to record the whole-brain activity of 39 older adults (over 60 years old) 37 young (aged 18-25 years) during recognition previously memorised varied musical sequences. Results reveal that when recognising sequences, compared reshapes its functional organisation. In fact, it shows increased early sensory regions such as left auditory cortex (100 ms 250 after each note), only moderate decreased (350 ms) medial temporal lobe prefrontal regions. When show a marked reduction fast-scale functionality (250 note) higher-order including hippocampus, ventromedial inferior cortices, while no differences are observed cortex. Accordingly, outperform novel behavioural regards ones. Our findings age-related changes memory processes, integrating existing theories on compensatory mechanisms non-pathological aging.

Language: Английский

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Musicianship and prominence of inter-hemispheric connectivity determine two different pathways to atypical language dominance

Journal of Neuroscience, Journal Year: 2024, Volume and Issue: 44(37), P. e2430232024 - e2430232024

Published: Aug. 19, 2024

During infancy and adolescence, language develops from a predominantly interhemispheric control—through the corpus callosum (CC)—to intrahemispheric control, mainly subserved by left arcuate fasciculus (AF). Using multimodal neuroimaging, we demonstrate that human left-handers (both male female) with an atypical lateralization show rightward participation of areas auditory cortex to inferior frontal when contrasting speech tone perception enhanced anatomical functional connectivity. Crucially, musicianship determines two different structural pathways this outcome. Nonmusicians present relation between underdevelopment across anterior AF, hinting at dysregulation ontogenetic shift brain. Musicians reveal alternative pathway related overdevelopment posterior CC cortex. We discuss heterogeneity in reaching relevance early musical training altering normal development cognitive functions.

Language: Английский

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Response strength and latencies of auditory steady-state responses from age six

International Journal of Audiology, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 10

Published: Jan. 7, 2025

Objective Auditory-steady state responses (ASSRs) to stimuli modulated by different frequencies may differ between children and adults. These differences in response characteristics or latency reflect developmental changes. This study investigates age-related strength, latencies, hemispheric laterality indices of ASSRs for modulation frequencies.

Language: Английский

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Handedness

Handbook of clinical neurology, Journal Year: 2025, Volume and Issue: unknown, P. 379 - 391

Published: Jan. 1, 2025

Language: Английский

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The arts and hemispheric specialization

Handbook of clinical neurology, Journal Year: 2025, Volume and Issue: unknown, P. 409 - 419

Published: Jan. 1, 2025

Language: Английский

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Cortical and behavioral tracking of rhythm in music: Effects of pitch predictability, enjoyment, and expertise

Annals of the New York Academy of Sciences, Journal Year: 2025, Volume and Issue: unknown

Published: March 18, 2025

Abstract The cortical tracking of stimulus features is a crucial neural requisite how we process continuous music. We here tested whether the beat, typically related to rhythm processing, modulated by pitch predictability and other top‐down factors. Participants listened tonal (high predictability) atonal (low music while undergoing electroencephalography. analyzed their acoustic envelope. Cortical envelope was stronger listening music, potentially reflecting listeners’ violated expectations increased attention allocation. Envelope also with more expertise enjoyment. Furthermore, showed surprisal (using IDyOM), which suggests that match those computed IDyOM model, higher for Behaviorally, measured participants’ ability finger‐tap beat sequences in two experiments. Finger‐tapping performance better condition, indicating positive effect on behavioral processing. predicted tapping as did pitch‐surprisal high low might impose different processing regimes. Taken together, our results show various ways factors impact musical

Language: Английский

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Predictive coding and dimension-selective attention enhance the lateralization of spoken language processing

Neuroscience & Biobehavioral Reviews, Journal Year: 2025, Volume and Issue: unknown, P. 106111 - 106111

Published: March 1, 2025

Hemispheric lateralization in speech and language processing exemplifies functional brain specialization. Seminal work patients with left hemisphere damage highlighted the left-hemispheric dominance functions. However, is not confined to hemisphere. Hence, some researchers associate auditory asymmetries: slow temporal fine spectral acoustic information preferentially processed right regions, while faster primarily handled by regions. Other scholars posit that relates more linguistic processing, particularly for speech-like stimuli. We argue these seemingly distinct accounts are interdependent. Linguistic analysis of relies on top-down processes, such as predictive coding dimension-selective attention, which enhance lateralized engaging left-lateralized sensorimotor networks. Our review highlights weaker simple sounds, stronger strongest meaningful speech. Evidence shows selective attention lateralization. illustrate processes rely networks provide insights into role processing.

Language: Английский

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