Biology subjects

Kanno, A.

Publications and source records attributed to Kanno, A..

6 recordsLinked to original sources

bioRxiv2026

BCCWJ-Brain: A Multi-Modal fMRI, MEG, and EEG Dataset of Naturalistic Japanese Reading

We present the BCCWJ-Brain dataset, a multi-modal neuroimaging resource comprising functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and electroencephalography (EEG) data recorded from native Japanese speakers reading newspaper articles from the Balanced Corpus of Contemporary Written Japanese (BCCWJ). Neural data were collected from 112 participants (36 fMRI, 35 MEG, and 41 EEG) as they read twenty newspaper articles presented in a Rapid Serial Visual Presentation (RSVP) paradigm. By providing three complementary neuroimaging modalities collected under identical naturalistic reading stimuli, this dataset provides a cognitive benchmark for computational models such as large language models. The dataset is publicly available on the OpenNeuro platform, offering a valuable resource for neuroscience, natural language processing, and related research fields.

neuroscience↗

bioRxiv2025

Whole-Brain Millisecond-Scale Effective Connectivity Atlas of Auditory and Visual Naming

Neurobiological models suggest that speech relies on interactions among distant cortical regions interconnected by white matter pathways. Prior studies have shown that speech-related functional coactivation--simultaneous high-gamma augmentation across distributed regions--reflects underlying neural interactions, as validated by electrical stimulation mapping. However, it remains unclear at the whole-brain level when, for how long, and in which directions cortical regions transmit information, and how dynamic information flows contribute to speech. Here, we investigated the causal roles of directional neural information flow during auditory and visual naming using intracranial EEG from 9,526 artifact-free nonepileptic sites across 127 patients. Information flow, estimated by transfer entropy-based effective connectivity, was classified as excitatory when high-gamma acceleration in one region predicted subsequent acceleration in another, and inhibitory when deceleration predicted downstream deceleration. Following stimulus onset, excitatory flows emerged from modality-specific sensory cortices and propagated to higher-order regions, later becoming bidirectional as functional coactivation developed. Each excitatory flow event was transient (<500 ms), typically followed by inhibitory flows and decreased coactivation, during which excitatory flows often emerged along new pathways. During auditory naming, faster response times were associated with stronger excitatory flows in left perisylvian regions; during visual naming, faster responses were linked to stronger flows in bilateral basal temporal cortices. Stronger excitatory flows at specific time points predicted a higher probability of stimulation-induced symptoms (Spearmans rho: 0.54-0.81; p<0.00001), whereas associations with inhibitory flows peaked later. Excitatory flows near visual naming response onset were particularly associated with stimulation-induced speech arrest and face sensorimotor symptoms, whereas functional coactivation alone failed to reveal comparable associations. These findings demonstrate that transient acceleration of directional neural interactions through white matter supports successive stages of speech processing. As activity within one pathway decelerates, excitatory flow accelerates along another, enabling functional transitions critical for naming. By establishing the causal contribution of temporally precise, anatomically specific white matter pathways, this study substantiates and extends existing neurobiological models of speech. To facilitate replication and dynamic whole-brain visualization, we provide open access to the full dataset (62.15 GB) and analysis code.

neuroscience↗

bioRxiv2025

Dynamic Causal White Matter Atlas of Auditory and Visual Speech Networks at Millisecond Resolution: Intracranial Evidence from 125 Patients

Background and ObjectivesSince the era of Penfield, invasive neurophysiology has laid a lasting foundation for functional neuroscience by elucidating brain regions necessary for speech. However, whole-brain investigations have yet to distinguish the millisecond-scale dynamics and specific white matter pathways that support rapid naming in the auditory and visual domains. MethodsIn this observational study, we constructed a whole-brain Dynamic Causal Tractography atlas using intracranial neurophysiological data from 125 neurosurgical patients. The resulting video atlas captured local cortical high-gamma activity and cortico-cortical coactivation via white matter tracts during rapid and delayed auditory and picture naming. Direct electrical stimulation was employed to assess the causal significance of the observed neural dynamics. ResultsThe atlas revealed white matter coactivation intensity patterns at specific 5-millisecond time windows that best aligned with sensorimotor and language symptoms elicited by electrical stimulation (Spearmans {rho} = 0.58-0.91; p = 4.8 x 10cc to 1.6 x 10c{superscript 2}c). Rapid auditory naming was associated with deactivation of the right rostral middle frontal gyrus and increased coactivation along the left arcuate fasciculus, linked to stimulation-induced receptive and expressive aphasia. In contrast, delayed auditory naming correlated with a late surge in bifrontal coactivation. Rapid picture naming involved early coactivation between cortices connected via the bilateral inferior longitudinal fasciculi--associated with stimulation-induced visual distortions--coinciding with transient co-inactivation of Brocas area. DiscussionThese findings delineate dissociable white matter-mediated mechanisms supporting rapid naming in the auditory and visual domains. Reduced inhibitory monitoring by the right dorsolateral prefrontal cortex may facilitate efficient lexical retrieval via left perisylvian pathways during auditory naming. In contrast, excessive bifrontal interaction may underlie delayed auditory naming. Rapid visual object recognition appears to rely on early occipitotemporal coactivation with minimal involvement of Brocas area. The resulting atlas--accompanied by a publicly available dataset (61.2 GB) and analysis code--serves as a valuable resource for students and trainees studying the network dynamics underlying speech, as well as for presurgical language mapping in patients undergoing cortical or subcortical intervention.

neuroscience↗

bioRxiv2025

Millisecond-Scale White Matter Dynamics Underlying Visuomotor Integration

In the conventional neuropsychological model, nonverbal visuospatial processing is predominantly handled by the right hemisphere, whereas verbal processing occurs in the left, with right-hand responses governed by the left motor cortex. Using intracranial EEG and MRI tractography, we investigated the timing and white matter networks involved in processing nonverbal visuospatial stimuli, forming response decisions, and generating motor outputs. Within 200 ms of stimulus onset, we observed widespread increases in functional connectivity and bidirectional neural flows from visual to association cortices, predominantly in the right hemisphere. Engagement of the right anterior middle frontal gyrus improved response accuracy; however, the accompanying enhancement in intra-hemispheric connectivity delayed response times. In the final 100 ms before right-hand response, functional connectivity and bidirectional communication via the corpus callosum between the right and left motor cortices became prominent. These findings provide millisecond-level support for the established model of hemispheric specialization, while highlighting a trade-off between accuracy and speed governed by the right dorsolateral prefrontal network. They also underscore the critical timing of callosal transmission of response decisions formed in right-hemispheric networks to the left-hemispheric motor system. HighlightsNeural information propagates through fasciculi during a visuomotor task. Non-verbal visuospatial analysis is mediated with right-hemispheric dominance. The right middle frontal gyrus improves response accuracy but delays responses. Interhemispheric information transfer occurs immediately before motor responses. This transfer between motor cortices is mediated by the corpus callosum.

neuroscience↗

bioRxiv2025

Dynamic Causal Tractography Analysis of Auditory Descriptive Naming:An Intracranial Study of 106 Patients

Humans understand and respond to spoken questions through coordinated activity across distributed cortical networks. However, the causal roles of connectivity engagements alternating across multiple white matter bundles remain understudied at the whole-brain scale. Using intracranial high-gamma activity recorded from 7,792 non-epileptic electrode sites in 106 epilepsy patients who underwent direct cortical stimulation mapping, we constructed an atlas visualizing the millisecond-scale dynamics of functional connectivity during a naming task in response to auditory questions. This atlas, the Dynamic Causal Tractography Atlas, identified functional connectivity patterns at specific time windows most strongly associated with stimulation-induced language- and speech-related manifestations (p-value range: 2.5 x 10-5 to 6.6 x 10-14; rho range: +0.54 to +0.82). The atlas revealed that no single intra-hemispheric fasciculus was consistently engaged in all naming stages; instead, each fasciculus supported specific stages, with multiple distinct major fasciculi simultaneously contributing to each stage. Additionally, this atlas identified the specific linguistic stages and fasciculi where handedness effects became evident. Our findings clarify the dynamics and causal roles of alternating, coordinated neural activity through specific fasciculi during auditory descriptive naming, advancing current neurobiological models of speech network organization. Additionally, we have made our white matter streamline template and intracranial EEG data available as open-source material, enabling investigators to construct personalized dynamic tractography atlases.

neuroscience↗

bioRxiv2021

Chromosome-scale haplotype-phased genome assemblies of the male and female lines of wild asparagus (Asparagus kiusianus), a dioecious plant species

Asparagus kiusianus is a disease-resistant dioecious plant species and a wild relative of garden asparagus (A. officinalis). To enhance A. kiusianus genomic resources, advance plant science, and facilitate asparagus breeding, we determined the genome sequences of the male and female lines of A. kiusianus. Genome sequence reads obtained with a linked-read technology were assembled into four haplotype-phased contig sequences (~1.6 Gb each) for the male and female lines. The contig sequences were aligned onto the chromosome sequences of garden asparagus to construct pseudomolecule sequences. Approximately 55,000 potential protein-encoding genes were predicted in each genome assembly, and ~70% of the genome sequence was annotated as repetitive. Comparative analysis of the genomes of the two species revealed structural and sequence variants between the two species as well as between the male and female lines of each species. Genes with high sequence similarity with the male-specific sex determinant gene in A. officinalis, MSE1/AoMYB35/AspTDF1, were presented in the genomes of the male line but absent from the female genome assemblies. Overall, the genome sequence assemblies, gene sequences, and structural and sequence variants determined in this study will reveal the genetic mechanisms underlying sexual differentiation in plants, and will accelerate disease-resistance breeding in garden asparagus.

genomics↗