Electromagnetic fields, such as those from mobile phones, alter regional cerebral blood flow and sleep and waking EEG.

Journal of sleep research · 2002 · Mixed · Low evidence

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MixedLow evidencePaper 5288

Study snapshot

PublicationJournal of sleep research · 2002

Study typerandomized_trial

Reported directionMixed

Evidence ratingLow

Abstract

Usage of mobile phones is rapidly increasing, but there is limited data on the possible effects of electromagnetic field (EMF) exposure on brain physiology. We investigated the effect of EMF vs. sham control exposure on waking regional cerebral blood flow (rCBF) and on waking and sleep electroencephalogram (EEG) in humans. In Experiment 1, positron emission tomography (PET) scans were taken after unilateral head exposure to 30-min pulse-modulated 900 MHz electromagnetic field (pm-EMF). In Experiment 2, night-time sleep was polysomnographically recorded after EMF exposure. Pulse-modulated EMF exposure increased relative rCBF in the dorsolateral prefrontal cortex ipsilateral to exposure. Also, pm-EMF exposure enhanced EEG power in the alpha frequency range prior to sleep onset and in the spindle frequency range during stage 2 sleep. Exposure to EMF without pulse modulation did not enhance power in the waking or sleep EEG. We previously observed EMF effects on the sleep EEG (A. A. Borbély, R. Huber, T. Graf, B. Fuchs, E. Gallmann and P. Achermann. Neurosci. Lett., 1999, 275: 207-210; R. Huber, T. Graf, K. A. Cote, L. Wittmann, E. Gallmann, D. Matter, J. Schuderer, N. Kuster, A. A. Borbély, and P. Achermann. Neuroreport, 2000, 11: 3321-3325), but the basis for these effects was unknown. The present results show for the first time that (1) pm-EMF alters waking rCBF and (2) pulse modulation of EMF is necessary to induce waking and sleep EEG changes. Pulse-modulated EMF exposure may provide a new, non-invasive method for modifying brain function for experimental, diagnostic and therapeutic purposes.

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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 typerandomized_trial

Effect directionmixed

Populationhumans

Sample sizeNot supplied

ExposureRF · 900 MHz · 30-min

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In Experiment 1, 30-min unilateral head exposure to pulse-modulated 900 MHz EMF (vs sham) increased relative regional cerebral blood flow in the dorsolateral prefrontal cortex ipsilateral to exposure. In Experiment 2, after EMF exposure, EEG power increased in the alpha range prior to sleep onset and in the spindle frequency range during stage 2 sleep; non-pulse-modulated EMF did not enhance waking or sleep EEG power.

Outcomes measured

regional cerebral blood flow (rCBF)
waking EEG power (alpha range)
sleep EEG power (spindle frequency range during stage 2 sleep)

Limitations

Sample size not reported in abstract.
Randomization/blinding procedures not described in abstract.
Exposure intensity (e.g., SAR) not reported in abstract.
Details of sham condition and exposure setup not provided in abstract.

View raw extracted JSON

{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": null,
    "duration": "30-min"
  },
  "population": "humans",
  "sample_size": null,
  "outcomes": [
    "regional cerebral blood flow (rCBF)",
    "waking EEG power (alpha range)",
    "sleep EEG power (spindle frequency range during stage 2 sleep)"
  ],
  "main_findings": "In Experiment 1, 30-min unilateral head exposure to pulse-modulated 900 MHz EMF (vs sham) increased relative regional cerebral blood flow in the dorsolateral prefrontal cortex ipsilateral to exposure. In Experiment 2, after EMF exposure, EEG power increased in the alpha range prior to sleep onset and in the spindle frequency range during stage 2 sleep; non-pulse-modulated EMF did not enhance waking or sleep EEG power.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in abstract.",
    "Randomization/blinding procedures not described in abstract.",
    "Exposure intensity (e.g., SAR) not reported in abstract.",
    "Details of sham condition and exposure setup not provided in abstract."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "electromagnetic field",
    "mobile phone",
    "pulse-modulated",
    "900 MHz",
    "PET",
    "regional cerebral blood flow",
    "EEG",
    "sleep",
    "alpha power",
    "spindle power",
    "stage 2 sleep",
    "sham control"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones-rf",
      "weight": 0.9,
      "reason": "Study tests 900 MHz pulse-modulated EMF exposure described as from mobile phones and measures brain physiology outcomes."
    }
  ]
}

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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: 10.1046/j.1365-2869.2002.00314.x
PubMed: 12464096

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