Evidence map›Paper›PMID 42755981›Full record

ArticleFrontiers in physiology2026

Critical flicker fusion frequency assessment: robustness across photopic illumination in experienced divers.

Jochen D Schipke, Thomas Muth, Anne-Kathrin Brebeck, Dominik von Hertlein, Fabian N Möller

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Article in Frontiers in physiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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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

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

5 authors.

Jochen D SchipkeResearch Group Experimental Surgery, University Hospital Duesseldorf, Duesseldorf, Germany.
Thomas MuthInstitute of Occupational, Social and Environmental Medicine, Heinrich-Heine-University Düsseldorf, Medical Faculty and University Hospital Düsseldorf, Frankfurt/Main, Germany.
Anne-Kathrin BrebeckArtemis Medizinisches Versorgungszentrum (MVZ) Frankfurt, Frankfurt/Main, Germany.
Dominik von HertleinDepartment of Psychology, German Sport University Cologne, Cologne, Germany.
Fabian N MöllerDepartment of Exercise Physiology, German Sport University Cologne, Cologne, Germany.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Introduction: Critical flicker fusion frequency (cFFF) is a rapid, noninvasive index of cortical arousal and visual-cognitive performance that has gained renewed interest in diving and other extreme environments. However, the extent to which ambient illumination and water submersion affect cFFF remains insufficiently characterized. Methods: Nineteen experienced divers (10 females; 24 ± 3 years) completed cFFF testing on land and at 5 m water depth under bright (land: 138 ± 2.4 lx; water: 75 ± 14.8 lx) and dark (0 lx) conditions using a manually operated flicker device. Heart rate (HR) and heart rate variability (HRV) were recorded continuously. Results: For cFFF, mixed-effects ANOVAs revealed a significant main effect of submersion (p=0.0485) but not illumination (p=0.0754), with higher values in submersion compared to land (+1.4 Hz). Heart rate variability showed a main effect for submersion (p=0.004, +30 ms in submersion) and posthoc differences in dark illumination (p=0.004, +41 ms in submersion). No effects were observed for heart rate or respiration rate. Age showed a low negative correlation with cFFF (r = -0.22 to -0.40) but not with heart rate or heart rate variability. Sex effects were negligible (|r|<0.32). Discussion: Based on the current 10-minute exposure time, cFFF is robust between the applied illuminations, but small absolute effects were observed from submersion. For human performance and diving research, these findings highlight the importance of baseline measures under comparable environmental conditions to prevent obscuring genuine changes in alertness or cognitive performance. Exposure time and ambient illumination should be standardized or reported to improve comparability across studies and operational environments.

Indexed as

arousalassessmentcritical flicker fusion frequencyenvironmenthyperbarismillumination

Identifiers

PMID42755981
PMCPMC13581964

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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.