Effects of low-level RF fields reveal complex pattern of magnetic input to the avian magnetic compass

Scientific reports · 2023 · Mixed · Low evidence

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MixedLow evidencePaper 365

Study snapshot

PublicationScientific reports · 2023

Study typeother

Reported directionMixed

Evidence ratingLow

Abstract

Effects of low-level RF fields reveal complex pattern of magnetic input to the avian magnetic compass Muheim R, Phillips JB. Effects of low-level RF fields reveal complex pattern of magnetic input to the avian magnetic compass. Sci Rep. 2023 Nov 15;13(1):19970. doi: 10.1038/s41598-023-46547-5. Abstract The avian magnetic compass can be disrupted by weak narrow-band and broadband radio-frequency (RF) fields in the lower MHz range. However, it is unclear whether disruption of the magnetic compass results from the elimination of the perception pattern produced by the magnetic field or from qualitative changes that make the pattern unrecognizable. We show that zebra finches trained in a 4-arm maze to orient relative to the magnetic field are disoriented when tested in the presence of low-level (~ 10 nT) Larmor-frequency RF fields. However, they are able to orient when tested in such RF fields if trained under this condition, indicating that the RF field alters, but does not eliminate, the magnetic input. Larmor-frequency RF fields of higher intensities, with or without harmonics, dramatically alter the magnetic compass response. In contrast, exposure to broadband RF fields in training, in testing, or in both training and testing eliminates magnetic compass information. These findings demonstrate that low-level RF fields at intensities found in many laboratory and field experiments may have very different effects on the perception of the magnetic field in birds, depending on the type and intensity of the RF field, and the birds' familiarity with the RF-generated pattern. pubmed.ncbi.nlm.nih.gov

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeother

Effect directionmixed

PopulationZebra finches

Sample sizeNot supplied

ExposureRF

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Zebra finches trained to orient relative to the magnetic field were disoriented when tested in low-level (~10 nT) Larmor-frequency RF fields, but could orient in the same RF fields if trained under that condition, suggesting altered (not eliminated) magnetic input. Higher-intensity Larmor-frequency RF fields (with or without harmonics) dramatically altered compass responses, while broadband RF exposure during training and/or testing eliminated magnetic compass information.

Outcomes measured

Magnetic compass orientation performance (disorientation vs ability to orient)
Alteration vs elimination of magnetic input/perception pattern

Limitations

Sample size not reported in the abstract
Exact RF frequencies (MHz values) not specified beyond 'lower MHz range' and 'Larmor-frequency'
Exposure duration and detailed exposure characterization not provided in the abstract
Outcome measures and statistical details not described in the abstract

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": "RF",
    "source": null,
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Zebra finches",
  "sample_size": null,
  "outcomes": [
    "Magnetic compass orientation performance (disorientation vs ability to orient)",
    "Alteration vs elimination of magnetic input/perception pattern"
  ],
  "main_findings": "Zebra finches trained to orient relative to the magnetic field were disoriented when tested in low-level (~10 nT) Larmor-frequency RF fields, but could orient in the same RF fields if trained under that condition, suggesting altered (not eliminated) magnetic input. Higher-intensity Larmor-frequency RF fields (with or without harmonics) dramatically altered compass responses, while broadband RF exposure during training and/or testing eliminated magnetic compass information.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in the abstract",
    "Exact RF frequencies (MHz values) not specified beyond 'lower MHz range' and 'Larmor-frequency'",
    "Exposure duration and detailed exposure characterization not provided in the abstract",
    "Outcome measures and statistical details not described in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "radio-frequency fields",
    "low-level RF",
    "Larmor-frequency",
    "broadband RF",
    "avian magnetic compass",
    "zebra finch",
    "magnetoreception",
    "orientation",
    "harmonics"
  ],
  "suggested_hubs": [
    {
      "slug": "rf-bioeffects",
      "weight": 0.78,
      "reason": "Experimental study of low-level RF field effects on a biological sensory system (avian magnetoreception) in the MHz range."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1038/s41598-023-46547-5
PubMed: 37968316

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