Biology subjects

Jaffe-Dax, S.

Publications and source records attributed to Jaffe-Dax, S..

8 recordsLinked to original sources

bioRxiv2026

Parents' neural dynamics in response to their children's speech

The development of speech in human children is a protracted process that depends on social experience. From early life, young children produce vocalizations in the presence of others, which affords unique opportunities for feedback about how to communicate successfully. However, for feedback to happen, young childrens speech needs to effect change in the brains of their caregivers. Using dual-brain functional near-infrared spectroscopy (fNIRS) to measure real-time communication between caregivers and their 2- to 3-year-old children (n = 56), we found that children's vocalizations selectively modulated caregivers' brain activity. Parents' brains showed a rapid response to children's production of speech that was communicatively advanced (multiword utterances) vs. less advanced (babble). The findings imply that if part of learning to talk is figuring out how to get your communication partner to listen, then early conversations likely present continuous opportunities for feedback that guide children toward advances in spoken language.

neuroscience↗

bioRxiv2026

Neural Evidence of Early Sensitivity to Text in Pre-reading Toddlers

Learning to read leads to widespread changes in brain organization, but it is not yet known when text first becomes a privileged stimulus. To test whether specialized neural responses to text appear prior to reading instruction, 31 monolingual toddlers in Israel (2.1-3.6 years) not yet enrolled in school were presented with displays of real, native text and visually matched non-text symbols. Using functional near-infrared spectroscopy, we found different patterns of activity in response to text vs. non-text across multiple cortical regions. Most notably, text elicited more activity in the ventrolateral prefrontal cortex, a region associated with language processing. These results challenge the view that the reading network emerges in response to gains in reading proficiency and instead suggest that through implicit sensitivity to regularities in their input, toddlers may be able to discover that text is a meaningful stimulus and begin to develop associations between language and text. Research HighlightsO_LIToddlers show different neural responses to real text vs. non-text symbols. C_LIO_LIUnfamiliar symbols evoke a novelty response in multiple cortical regions. C_LIO_LIText elicits more activity in a left ventrolateral prefrontal cortex, a region associated with processing language. C_LIO_LIBefore they know how to read, toddlers may recognize text as a frequent, familiar stimulus that is linked to language. C_LI

neuroscience↗

bioRxiv2026

The Adaptive Brain Across Development: Age Related Changes in Cortical Adaptation

How does the functionality of the cortex change from infancy to adulthood to support the developmental cognitive shift from learners to performers? Cortical adaptation is a simple neural mechanism which plays a key role in learning and memory encoding, but little is known about how it develops across the lifespan. Both infants and adults have been found to respond differently to repeating audio and visual stimuli, suggesting differences in cortical adaptation throughout development. However, studies typically approach these populations through different paradigms and interpret the results in terms of different cognitive models. To overcome these issues, we implemented an identical paradigm across all age groups to examine cortical adaptation and its developmental trajectory. We used functional near infra-red spectroscopy (fNIRS) to chart how different regions in the infant, child and adult brain respond to repeating audiovisual stimuli at varying inter-stimulus intervals (ISIs), using cortical adaptation as a proxy for implicit memory dynamics. We found faster recovery from adaptation in infants compared to children and adults. Specifically, there was an interaction between stimulus presentation rate and age in the right temporal, left parietal and occipital cortical areas. There was also a developmental progression in functional connectivity, with infants displaying significantly lower correlations between regions of interest than children and adults. Taken together, we suggest these findings may reflect the developmental trajectory of cortical adaptation from a learning system optimized for maximal information intake and minimal filtering of stimuli to a specialized integrative system that efficiently filters and adapts to information. HighlightsO_LICortical adaptation is a fundamental mechanism involved in memory and learning, but not much is known about how it develops throughout the lifespan. C_LIO_LIAn identical fNIRS paradigm across 3 different age groups reveals significant differences in cortical adaptation between infants, children and adults. C_LIO_LIFunctional connectivity revealed foundational connections present from infancy, growing stronger and into a specialized adaptation system with age. C_LI These findings suggest a developmental transition from a system optimized for maximal information intake to a specialized learning system, capable of filtering redundant information.

neuroscience↗

bioRxiv2021

Sequence learning attenuates cortical responses in both frontal and perceptual cortices in early infancy

Prior work has found that the frontal lobe is involved in higher-order sequential and statistical learning in young infants. Separate lines of work have found evidence of modulation of posterior sensory cortices during and after learning tasks. How do these processes relate? Here, we build evidence the infant frontal lobe was modulated during sequential learning and ask whether posterior perceptual cortices show corresponding modulation. First, replicating and extending past work, we found evidence of frontal lobe involvement in this task. Second, consistent with our hypotheses, we found that there is a corresponding attenuation of neural responses in the posterior perceptual cortices (temporal and occipital) to predictable compared to unpredictable audiovisual sequences. This study provides convergent evidence that the frontal lobe is crucial for higher-level learning in young infants but that it likely works as part of a large, distributed network of regions to modulate infant neural responses during learning. Overall, this work challenges the view that the infant brain is not dynamic and disconnected, lacking in long-range neural connections. Instead, this paper reveals patterns of a highly dynamic and interconnected infant brain that change rapidly as a result of new, learnable experiences.

neuroscience↗

bioRxiv2020

STORM-Net: Simple and Timely Optode Registration Method for Functional Near-Infrared Spectroscopy (fNIRS)

We introduce a robust video-based method for estimating the positions of fNIRS optodes on the scalp. The method is fast, requires no special hardware, and is intuitive to use with developmental populations. Co-registration is a crucial step for reliable analysis of FNIRS data, yet it still remains an open problem when considering these populations. Existing methods pose motion constraints, require expert annotation, or are only applicable in laboratory conditions. Using novel computer-vision technologies, we implement a fully-automatic appearance-based method that estimates the registration parameters of a mounted cap to the scalp from a raw video of the subject. We validate our method on 10 adult subjects and demonstrate its usability with infants. We compare our method to the standard 3D digitizer, and to other photogrammetry based approaches. We show our method achieves comparable accuracy to current appearance-based methods, while being orders of magnitude faster. Our fast registration facilitates more spatially precise fNIRS analysis with developmental populations even in unconventional environments. The method is implemented as a open-source toolbox at https://github.com/yoterel/STORM-Net.

neuroscience↗

bioRxiv2019

Video-based motion-resilient reconstruction of 3D position for fNIRS/EEG head mounted probes

SignificanceWe propose a novel video-based, motion-resilient, and fast method for estimating the position of optodes on the scalp. AimMeasuring the exact placement of probes (e.g., electrodes, optodes) on a participants head is a notoriously difficult step in acquiring neuroimaging data from methods which rely on scalp recordings (e.g., EEG and fNIRS), and is particularly difficult for any clinical or developmental population. Existing methods of head measurements require the participant to remain still for a lengthy period of time, are laborious, and require extensive training. Therefore, a fast and motion-resilient method is required for estimating the scalp location of probes. ApproachWe propose an innovative video-based method for estimating the probes positions relative to the participants head, which is fast, motion-resilient, and automatic. Our method builds on capitalizing the advantages, and understanding the limitations, of cutting-edge computer vision and machine learning tool. We validate our method on 10 adult subjects and provide proof of feasibility with infant subjects. ResultsWe show that our method is both reliable and valid compared to existing state-of-the-art methods by estimating probe positions in a single measurement, and by tracking their translation and consistency across sessions. Finally, we show that our automatic method is able to estimate the position of probes on an infant head without lengthy offline procedures, a task which is considered challenging until now. ConclusionsOur proposed method allows, for the first time, the use of automated spatial co-registration methods on developmental and clinical populations, where lengthy, motion-sensitive measurement methods routinely fail.

neuroscience↗

bioRxiv2017

Widespread shorter cortical adaptation in dyslexia

Studies of dyslexics performance on perceptual tasks suggest that their implicit inference of sound statistics is impaired. In a previous paper (Jaffe-Dax, Frenkel, & Ahissar, 2017), using 2-tone frequency discrimination, we found that the effect of previous trial frequencies on dyslexics judgments decayed faster than the effect on controls judgments, and that the adaptation of their ERP responses to tones recovered faster. Here, we show the cortical distribution of this abnormal dynamics of adaptation using fast acquisition fMRI. We find that dyslexics faster decay of adaptation is widespread, though the most significant effects are found in the left superior temporal lobe, including the auditory cortex. This broad distribution suggests that dyslexics faster decay of implicit memory is a general characteristic of their cortical dynamics, which also encompasses the sensory cortices.

neuroscience↗

bioRxiv2016

Shorter neural adaptation to sounds accounts for dyslexics’ abnormal perceptual and reading dynamics

Dyslexia is a prevalent reading disability whose underlying mechanisms are still disputed. We studied the neural mechanisms underlying dyslexia using a simple frequency-discrimination task. Though participants were asked to compare the 2-tones in each trial, implicit memory of previous trials affected their responses. We hypothesized that implicit memory decays faster among dyslexics. We tested this by increasing the temporal intervals between consecutive trials, and measuring the behavioral impact and ERP responses from the auditory cortex. Dyslexics showed a faster decay of implicit memory effects on both measures, with similar time constants. Finally, faster decay also characterized dyslexics benefits in oral reading rate. It decreased faster as a function of the time interval from the previous reading of the same non-word. We propose that dyslexics shorter neural adaptation paradoxically accounts for their longer reading times, since it induces noisier and less reliable predictions for both simple and complex stimuli.

neuroscience↗