Evidence map›Paper›PMID 41876658›Full record

ArticleScientific reports2026

Chaotic fluctuations mark the sign of mental activity in task-based heart rate variability.

Tomoyuki Mao, Hidetoshi Okutomi, Ken Umeno

Erratum issuedAbstract read
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Article in Scientific reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

3 authors.

Tomoyuki Mao *Department of Applied Mathematics and Physics, Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan. tomoyuki.mao.f28@mail.toshiba.
Hidetoshi Okutomi *Technology Management Division, Toshiba Information Systems (Japan) Corporation, Kawasaki-ku, Kawasaki, Kanagawa, 210-8540, Japan.
Ken Umeno *Department of Applied Mathematics and Physics, Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan. umeno.ken.8z@kyoto-u.ac.jp.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Heart rate variability (HRV), regulated by the autonomic nervous system, is typically assessed using standard time-domain and frequency-domain methods to evaluate autonomic function. However, conventional linear analyses capture only a limited aspect of HRV, as the human body, including the cardiovascular system, is intrinsically nonlinear. In light of this, there has been growing interest in nonlinear analyses grounded in chaos theory and complexity science. In this study, we conducted a comprehensive comparison of time-domain, frequency-domain, and chaos/complexity indices derived from R-R interval (RRI) analysis during both physical and mental tasks. The results clearly demonstrate a significant increase in chaos/complexity indices during mental tasks, while conventional indices remain unchanged-underscoring the unique sensitivity of nonlinear measures to cognitive processes. These findings highlight the relevance of chaotic dynamics and complexity in HRV as a valuable perspective for understanding brain-heart interactions. Furthermore, based on the experimental findings, we propose a new hypothesis, consistent with previous research, regarding the emergence of chaotic features in HRV during cognitive activity.

Indexed as

CognitionHeart RateAutonomic Nervous SystemElectrocardiographyHumansMaleNonlinear Dynamics

Identifiers

PMID41876658
PMCPMC13013681

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.