Biology subjects

Dalski, A.

Publications and source records attributed to Dalski, A..

6 recordsLinked to original sources

bioRxiv2026

Preliterate symbolic language processing sets the neural stage for learning to read

Formal writing is evolutionarily recent, yet the brains of literate adults contain regions - the OTS-words subregions - that respond more strongly to written text than other stimuli. We tested a novel solution to this multi-disciplinary paradox: Does symbolic language processing, which emerged early in human history, lay the neural foundation for reading? In a longitudinal fMRI study, we followed 17 children through their first year of literacy training and related neural responses to text, symbolic language processing, and emerging reading skills over time. We found that middle OTS-words is engaged in symbolic language processing before children learn to read, and that this early engagement predicts later text selectivity and reading ability. These findings suggest that literacy builds on a pre-existing neural scaffold linking vision and language.

neuroscience↗

bioRxiv2025

A fast and child-friendly localizer for the identification of ITG-math based on its preference for mathematical processing

The visual number form areas (here referred to as ITG-math) have gained recent attention as a neural substrate of mathematical cognition. Yet, the function of these regions remains debated with some research suggesting selectivity for digits and others suggesting a visual stimulus-independent role in mathematical processing. Here we addressed this debate by exploring the impact of different tasks and stimuli on neural responses in ITG-math. Participants were presented with digits and UFOs, while performing a 1-back task either on stimulus numerosity or on stimulus color. We collected two sessions of this experiment from 17 healthy adults and could identify voxels with higher responses in the numerosity than the color task in 92% of the participants, whereas contrasting digits with UFOs lead to selective responses in only 35% of the participants. Accordingly, in independent data, ITG-math showed a task preference, but no stimulus preference. Multivariate analyses further revealed task encoding, and a combination of task and stimulus encoding, in the left and right ITG-math, respectively. Our work hence supports the notion that the role of ITG-math in mathematical cognition goes beyond the encoding of digits.

neuroscience↗

bioRxiv2023

Both mOTS-words and pOTS-words prefer emoji stimuli over text stimuli during a reading task

The visual word form area in the occipitotemporal sulcus (OTS), here referred to as OTS-words, responds more strongly to text than other visual stimuli and is crucial for reading. We hypothesized, that this text preference may be driven by a preference for reading tasks, as in most prior fMRI studies only the text stimuli were readable. Hence, we performed three fMRI experiments (N=15) and systematically varied the participant s task and the stimulus, investigating mOTS-words and pOTS-words subregions. In experiment 1, we contrasted text stimuli with non-readable visual stimuli (faces, limbs, houses, objects). Experiment 2 utilized an fMRI adaptation paradigm, presenting compound words in text or emoji formats. In experiment 3, participants performed a reading or a color task on compound words in text or emoji format. Using experiment 1 data, we identified mOTS-words and pOTS-words by contrasting texts with non-readable stimuli. In experiment 2, pOTS-words, but not mOTS-words, showed fMRI adaptation for compound words in both text and emoji formats. In experiment 3, surprisingly, both subregions showed higher responses to compound words in emoji than text format. Moreover, mOTS-words showed higher responses during the reading than the color task and a task-stimulus interaction. Multivariate analyses revealed that distributed responses in pOTS-words encode the visual stimulus, while responses in mOTS-words encode both stimulus and task. Together, our findings suggest that the function of the OTS-words subregions goes beyond the specific visual processing of text and that these regions are flexibly recruited whenever semantic meaning needs to be assigned to visual input. Significance StatementReading skills are essential in modern society and supported by a brain region in the occipitotemporal sulcus (OTS-words) that is critical for fluent reading. Here we evaluated if responses in OTS-words are driven by the activity of reading or simply by seeing text or other readable symbols (emojis). We found that OTS-words can be divided into two sub-regions which both prefer readable emojis over text, whereas the anterior sub-region also prefers reading over other tasks. These results suggest that OTS-words is flexibly recruited to encode any readable visual stimulus, not just text. By demonstrating OTS-words flexibility, this work reconciles previous contradictory findings on this regions functional properties and inspires future research on OTS-words, including its emergence during literacy acquisition.

neuroscience↗

bioRxiv2022

Characterizing the shared signals of face familiarity: long-term acquaintance, voluntary control, and concealed knowledge

Using cross-experiment multivariate classification of EEG patterns, in a recent study we found evidence for a shared familiarity signal for faces, patterns of neural activity that successfully separate trials for familiar and unfamiliar faces across participants and modes of familiarization. Here, our aim was to expand upon this research to further characterize the spatio-temporal properties of this signal. By utilizing the information content present for incidental exposure to personally familiar and unfamiliar faces, we tested how the information content in the neural signal unfolds over time under different task demands - giving truthful or deceptive responses to photographs of genuinely familiar and unfamiliar individuals. For this goal, we re-analyzed data from two previously published experiments using within-experiment leave-one-subject-out and cross-experiment classification of face familiarity. We observed that the general face familiarity signal, consistent with its previously described spatio-temporal properties, is present for long-term personally familiar faces under passive viewing, as well as for acknowledged and concealed familiarity responses. Also, central-posterior regions contain information related to deception. We propose that signals in the 200-400 ms window are modulated by top-down task-related anticipation, while the patterns in the 400-600 ms window are influenced by conscious effort to deceive. To our knowledge, this is the first report describing the representational dynamics of concealed knowledge for faces. HighlightsO_LIPrevious studies found a robust EEG effect for face-familiarity in the 200-600 ms post-stimulus range. C_LIO_LIThis neural pattern was found to be shared across participants and modes of familiarization. C_LIO_LIWe used incidental exposure as a template to probe information content for acknowledged and concealed familiarity C_LIO_LIThe shared familiarity signal is modulated differentially in early (200-400 ms) and late (post-400 ms) windows C_LIO_LICross-experiment classification is a promising tool to investigate how cognitive processes unfold under different conditions C_LI

neuroscience↗

bioRxiv2022

No Semantic Information is Necessary to Evoke General Neural Signatures of Face Familiarity - Evidence from Cross-Experiment Classification

Recent theories on the neural correlates of face identification stressed the importance of the available identity-specific semantic and affective information. However, whether such information is essential for the emergence of neural signal of familiarity has not yet been studied in detail. Here, we explored the shared representation of face familiarity between perceptually and personally familiarized identities. We applied a cross-experiment multivariate pattern classification analysis (MVPA), to test if EEG patterns for passive viewing of personally familiar and unfamiliar faces are useful in decoding familiarity in a matching task where familiarity was attained thorough a short perceptual task. Importantly, no additional semantic, contextual, or affective information was provided for the familiarized identities during perceptual familiarization. Although the two datasets originate from different sets of participants who were engaged in two different tasks, familiarity was still decodable in the sorted, same identity matching trials. This finding indicates that the visual processing of the faces of personally familiar and purely perceptually familiarized identities involve similar mechanisms, leading to cross-classifiable neural patterns.

neuroscience↗

bioRxiv2021

Evidence for a general neural signature of face familiarity

We explored the neural signatures of face familiarity using cross-participant and cross-experiment decoding of event-related potentials, evoked by unknown and experimentally familiarized faces from a set of experiments with different participants, stimuli, and familiarization-types. Participants were either familiarized perceptually, via media exposure, or by personal interaction. We observed significant cross-experiment familiarity decoding involving all three experiments, predominantly over posterior and central regions of the right hemisphere in the 270 - 630 ms time window. This shared face familiarity effect was most prominent between the Media and Personal, as well as between the Perceptual and Personal experiments. Cross-experiment decodability makes this signal a strong candidate for a general neural indicator of face familiarity, independent of familiarization methods and stimuli. Furthermore, the sustained pattern of temporal generalization suggests that it reflects a single automatic processing cascade that is maintained over time. HighlightsO_LIWe investigated if a general neural signature of face familiarity exist C_LIO_LIA cross-experiment decoding analysis of EEG data was used C_LIO_LIThe analysis involved perceptual, media and personal familiarization methods C_LIO_LIWe found a preserved pattern of familiarity decoding across experiments between 270 and 630 ms post-stimulus C_LIO_LIThis signature is consistent with previous reports on face familiarity effects C_LI

neuroscience↗