Biology subjects

Skeide, M. A.

Publications and source records attributed to Skeide, M. A..

9 recordsLinked to original sources

bioRxiv2026

Multisensory integration while learning to read: A longitudinal functional and structural MRI study

Literacy development involves the recognition and integration of auditory and visual signals and as such offers a unique opportunity to track the development of an eventually efficient multisensory processing network. To shed light on this topic we conducted a 12-month longitudinal 3 Tesla functional and structural MRI study in children beginning to receive formal literacy instruction. Twenty-three six-year-old German-speaking participants completed four fMRI sessions during which they were presented with letters, speech sounds, or their audiovisual combinations in congruent and incongruent formats. Longitudinal changes in BOLD response amplitude were assessed using linear mixed-effects models. Over the course of learning to read, we observed significant changes in modulations of BOLD activity for the congruent - incongruent contrast within a left-lateralised network encompassing the central opercular cortex, anterior supramarginal gyrus, inferior frontal gyrus (pars triangularis) and frontal pole. These effects were primarily driven by a gradual increase of response amplitude across sessions, consistent with the refinement of audiovisual integration mechanisms. Structural analyses revealed longitudinal anatomical variation within temporal, occipital, and sensorimotor regions, predominantly involving the right middle and inferior temporal gyri and bilateral temporal regions. However, changes in regional anatomy and functional activation were not significantly associated with behavioural measures of grapheme-phoneme association. Together, these findings demonstrate reorganisation within established regions known to be related to language processing and multisensory integration during early literacy development, highlighting the utility of longitudinal MRI for tracking experience-dependent neuroplastic changes in brain function and structure.

neuroscience↗

bioRxiv2026

Development of Audiovisual Integration in Beginning Readers: A Longitudinal fMRI Study

Acquiring reading proficiency, unlike spoken language, requires the brain to engage several specialized neural systems to map visual symbols (letters) to their corresponding phonological sounds (audiovisual integration), laying the foundation for fluent reading. This study investigates the neural and behavioral trajectory of developing audiovisual (AV) integration during the first year of learning to read. Thirty-two healthy Hebrew-speaking first-grade children were assessed at 3 time points across the school year: beginning, middle, and end of first grade. Participants underwent behavioral testing and brain fMRI scans while performing a block-design fMRI task involving AV matching or non-matching letters and sounds. Together with improvement in behavioral test scores related to general abilities, working memory, cognitive flexibility, and phonemic abilities, a Drift Diffusion Modeling (DDM) analysis of the accuracy and reaction time across sessions suggested faster and more efficient responses as the year progressed. fMRI results showed a significant increase in activation, from the beginning to the end of the first grade, in the left superior temporal gyrus (STG), frontal cortices and parietotemporal cortices, with a shift towards left-lateralization in the fusiform gyrus at the end of the year. These findings point towards the second half of the first grade as the time window for neural specialization and lateralization to phonological and orthographic information. A significant positive correlation between the fusiform gyrus activation and naming objects and colors scores across all sessions links this neural specialization to cognitive flexibility behavioral skills. Key pointsO_LISignificant increase, predominantly between the middle and end of the first grade, in activation in fusiform, left superior temporal, frontal, and parietotemporal cortices across the first grade. C_LIO_LISignificant left lateralization in the fusiform gyrus at the end of first grade. C_LIO_LIPositive correlation between naming skills and a bilateral fusiform gyrus activation throughout the first grade. C_LI

animal behavior and cognition↗

bioRxiv2026

Disambiguation of two-tone images reveals semantic contributions to object recognition in the EEG

Electrophysiological responses to visual objects carry information about stimulus identity and semantic category, but it remains difficult to know whether such information represents semantic knowledge or merely regularities in physical image features. Here, we presented two-tone images while recording EEG to dissociate the learned semantic concept from physical stimulus properties in the electrophysiological signal. Seventeen healthy participants completed a semantic disambiguation experiment with three phases: ambiguous two-tone images before disambiguation, their corresponding grayscale photographs, and the same two-tone images after disambiguation. We quantified representational change using Mahalanobis distances between EEG response patterns. After disambiguation, EEG responses to learned two-tone images became more similar to the response of their photo counterparts, indicating semantic enrichment of stimulus-specific representations. This effect emerged approximately 100 ms after stimulus onset and persisted across an extended time window. However, we found no evidence for an increase in semantic category-level responses after disambiguation. Furthermore, responses to spontaneously recognized two-tone images did not already show stronger alignment with the responses to their corresponding photo images before explicit visual disambiguation was performed. Together, these findings show that EEG can capture learned semantic modulations of responses to visually degraded stimuli, while also indicating that low-level visual properties dominate the representational structure. Two-tone images can therefore serve as a useful paradigm for probing semantic learning in the EEG, and may guide future research in children and patient populations whose ability to behaviorally confirm learning is limited.

neuroscience↗

bioRxiv2026

Representational similarity of hemodynamic brain responses to written and spoken words increases when learning to read

Learning to read requires binding auditory and visual information together, yet how the developing brain maps information across sensory modalities remains poorly understood. To shed light on this topic we employed functional magnetic resonance imaging to investigate hemodynamic brain responses during spoken and written word or pseudoword recognition in primary school children with different levels of reading experience. Audiovisual representational similarity of activation patterns in the inferior frontal gyrus, inferior parietal lobule, superior temporal gyrus, and temporo-occipital cortex, increased with school grade and this similarity was largest in the left posterior superior temporal gyrus. Our results suggest that learning to read is related to increasing neurophysiological similarity of auditory and visual word representations within canonical language areas.

neuroscience↗

bioRxiv2025

Replay of episodic experience in human infants

Sequentially structured and temporally compressed reactivation of memory contents plays a key role for learning in the mature mammalian brain. This type of neural coding, known as replay, could also drive the enormous progress in sequential learning seen in human early life. Rodent models, however, suggest that replay emerges slowly and refines gradually in childhood. To test whether this prediction holds in humans, we introduced a novel fast event-related stimulation paradigm for infants undergoing non-invasive electroencephalography. Leveraging time-resolved decoding techniques we discovered multimodal replay already in infants as young as 10 months. Reactivation responses revealed a forward sequential structure and temporal compression of the learnt sequence by a factor of 6 to 7. These results demonstrate cued replay activity at the macroscopic level in the first year of life, an age at which it has not been found in rodent place cells. Our insights stimulate future research exploring how replay contributes to the development of fundamental human cognitive capacities including language processing and action planning.

neuroscience↗

bioRxiv2025

High-field fMRI at 7 Tesla reveals topographic responses tuned to number in the developing human brain

In the adult brain, hemodynamic responses to visually presented numerosities reveal receptive field-like tuning curves in topographically organized maps across association cortices. It is currently unknown whether such tuned topographic responses to numerosities can also be detected in the developing brain. Here we conducted a 7 Tesla fMRI experiment in which we presented a large set of visual dot displays to 11-12-year-old children and adults. We found that developing hemodynamic responses indeed revealed logarithmic Gaussian tuning to quantitative information. Tuning models explained comparable amounts of variance in children and adults. In most subjects, six bilateral cortical maps consistently exhibited topographic responses to numerosities. The present study goes beyond previous work by uncovering a population code for quantity detection in individual developing human brains. Our work lays a foundation for a model-based neuroimaging approach to individual cognitive differences in the context of developmental dyscalculia and mathematical giftedness.

neuroscience↗

bioRxiv2024

Electrophysiological decoding captures the temporal trajectory of face categorization in infants

The adult human brain rapidly distinguishes between faces at around 170 milliseconds after stimulus onset. In the developing brain, however, the time course of face discrimination is poorly understood. To shed light on this issue, we presented human and nonhuman primate faces to five to thirteen-month-old infants in an event-related electroencephalography experiment. Using time-resolved decoding based on logistic regression we detected above-chance discrimination of human faces from nonhuman faces in a time window starting at around 200 milliseconds, originating from occipito-temporal electrodes. There was no evidence, however, for above-chance discrimination of individual human or individual nonhuman faces. Moreover, using neural network-based decoding, we delivered the proof of principle that face categorization but not individuation can be detected even at the level of single participants. These results indicate that rapid face categorization emerges already in preverbal infants.

neuroscience↗

bioRxiv2024

Population connective field modeling reveals retinotopic visual cortex organization in the prenatal human brain

The visual space is sampled by cortical field maps in which nearby neuronal populations encode nearby locations of images received from the retina. Whether retinotopic cortical organization already emerges in the neonatal or even prenatal human brain is currently unknown. To answer this question in vivo, we applied population connective field modeling to 871 resting-state functional magnetic resonance imaging datasets ranging from prenatal to young adult age. We found topographically organized eccentricity and polar angle connectivity maps in V2 and V3 of the visual cortex as early as the 21st week of gestation. These results highlight that human proto-retinotopic cortical maps develop in the second trimester of pregnancy, predating visual experience.

neuroscience↗

bioRxiv2021

A Meta-Analysis of fMRI Studies of Semantic Cognition in Children

Our capacity to derive meaning from things that we see and words that we hear is unparalleled in other animal species and current AI systems. Despite a wealth of functional magnetic resonance imaging (fMRI) studies on where different semantic features are processed in the adult brain, the development of these systems in children is poorly understood. Here we conducted an extensive database search and identified 50 fMRI experiments investigating semantic world knowledge, semantic relatedness judgments, and the differentiation of visual semantic object categories in children (total N = 1,018, mean age = 10.1 years, range 4-15 years). Synthesizing the results of these experiments, we found consistent activation in the bilateral inferior frontal gyri (IFG), fusiform gyri (FG), and supplementary motor areas (SMA), as well as in the left middle and superior temporal gyri (MTG/STG). Within this system, we found little evidence for age-related changes across childhood and high overlap with the adult semantic system. In sum, the identification of these cortical areas provides the starting point for further research on the mechanisms by which the developing brain learns to make sense of its environment.

neuroscience↗