Biology subjects

Shoura, M.

Publications and source records attributed to Shoura, M..

5 recordsLinked to original sources

bioRxiv2026

Face ensembles reshape the neural other-race effect

The other-race effect (ORE), poorer recognition of other-race (OR) than same-race (SR) faces, is established for individual faces, but its neural expression during group viewing remains unclear. Twenty-two East Asian adults viewed East Asian and White faces in different formats: individually and in six-face ensembles during EEG recording. Behavioral testing confirmed an SR advantage. Decoding and generative reconstruction characterized neural discriminability, geometry, dynamics, sensor-level information, and recoverable content. Single SR faces were more discriminable, more dispersed in face space, and reconstructed more accurately. Ensembles preserved racial-composition information but reduced the cumulative SR-OR decoding difference and showed instead an early OR advantage. Reconstructions supported identification of individual faces and ensemble summaries, with an overall SR advantage but no reliable race-by-format interaction. Independent judgments revealed race- and format-dependent shifts in reconstructed age, valence, and arousal. These findings reveal a neural ORE whose expression depends on viewing context and representational measure.

neuroscience↗

bioRxiv2025

Decoding the dynamics of cognitive control: Insights from reach movements and electroencephalography

The congruency sequence effect (CSE) refers to improved performance in conflict tasks, such as the Eriksen flanker task, when the congruency of the current trial matches that of the preceding one. Although widely attributed to dynamic adjustments in cognitive control, the neural mechanisms and temporal dynamics underlying this effect remain poorly understood. Here, we combined a release-and-press flanker task with EEG decoding to examine how trial congruency and response type shape behavior and brain activity in healthy adults. Behaviorally, the CSE emerged only when responses repeated, highlighting the dominant role of stimulus-response binding over abstract control mechanisms. Neural decoding mirrored the CSE: current-trial congruency was more reliably decoded on repeated-response trials following congruent versus incongruent trials. This neural CSE was stimulus-locked, occurred between 450-550ms post-stimulus onset, and was driven by theta-band activity. More broadly, congruency decoding was particularly robust over frontal channels while cross-temporal generalization indicated transient, sequential neural representations underlying control signals. Together, these findings demonstrate that both behavioral and neural signatures of the CSE are tightly constrained by response repetition and emerge within a narrow temporal window. By integrating reach-based measures with multivariate EEG analyses, this study provides a fine-grained account of when, where, and under what conditions control-related signals unfold after conflict.

neuroscience↗

bioRxiv2025

Nucleosome-mediated conformational switches in micro-eccDNAs

Extrachromosomal-circular DNA (eccDNA) are circular-DNA elements that are implicated in cellular processes such as genomic diversification and instability, along with other genomic mechanisms. However, their structure and chromatinization state is poorly understood. Here we identified a 358-bp circular micro-eccDNA molecule derived from the human Titin gene, which was selected for this study based on its size and sequence characteristics, and used atomistic molecular dynamics simulations to study its interaction with nucleosomes and corresponding topological state. We show the presence or absence of bound nucleosomes provides a topological switch between intact and denatured DNA.

biophysics↗

bioRxiv2024

Revealing the neural representations underlying other-race face perception

The other-race effect, a disadvantage at recognizing faces of other races than ones own, has received considerable attention, especially regarding its wide scope and underlying mechanisms. Here, we aim to elucidate its neural and representational basis by relating behavioral performance in East Asian and White individuals to neural decoding and image reconstruction relying on electroencephalography data. Our investigation uncovers a reliable neural counterpart of the other-race effect (i.e., a decoding disadvantage for other-race faces) along with its extended dynamics and prominence across individuals. Further, it retrieves, via neural-based image reconstruction, visual representations underlying other-race face perception and their intrinsic biases. Notably, our data-driven approach reveals that other-race faces are perceived not just as more typical but, also, as younger and more expressive. These findings, pointing to multiple visual biases surrounding the other-race effect, speak to the complexity of its neural mechanisms and its social implications.

neuroscience↗

bioRxiv2017

Beyond The Linear Genome: Comprehensive Determination Of The Endogenous Circular Elements In C. elegans And Human Genomes Via An Unbiased Genomic-Biophysical Method

Investigations aimed at defining the 3-D configuration of eukaryotic chromosomes have consistently encountered an endogenous population of chromosome-derived circular genomic DNA, referred to as extrachromosomal circular DNA (eccDNA). While the production, distribution, and activities of eccDNAs remain understudied, eccDNA formation from specific regions of the linear genome has profound consequences on the regulatory and coding capabilities for these regions. High-throughput sequencing has only recently made extensive genomic mapping of eccDNA sequences possible and had yet to be applied using a rigorous approach that distinguishes ascertainment bias from true enrichment. Here, we define eccDNA distribution, utilizing a set of unbiased topology-dependent approaches for enrichment and characterization. We use parallel biophysical, enzymatic, and informatic approaches to obtain a comprehensive profiling of eccDNA in C. elegans and in three human cell types, where eccDNAs were previously uncharacterized. We also provide quantitative analysis of the eccDNA loci at both unique and repetitive regions. Our studies converge on and support a consistent picture in which endogenous genomic DNA circles are present in normal physiological DNA metabolism, and in which the circles come from both coding and noncoding genomic regions. Prominent among the coding regions generating DNA circles are several genes known to produce a diversity of protein isoforms, with mucin proteins and titin as specific examples.

genomics↗