Effects of electromagnetic field emitted by cellular phones on the EEG during an auditory memory task: a double blind replication study.

Bioelectromagnetics · 2004 · Mixed · Low evidence

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MixedLow evidencePaper 5241

Study snapshot

PublicationBioelectromagnetics · 2004

Study typerandomized_trial

Reported directionMixed

Evidence ratingLow

Abstract

The effects of electromagnetic fields (EMF) emitted by cellular phones on the event related desynchronization/synchronization (ERD/ERS) of the 4-6, 6-8, 8-10, and 10-12 Hz electroencephalogram (EEG) frequency bands were studied in 24 normal subjects performing an auditory memory task. This study was a systematic replication of our previous work. In the present double blind study, all subjects performed the memory task both with and without exposure to a digital 902 MHz field in a counterbalanced order. We were not able to replicate the findings from our earlier study. All eight of the significant changes in our earlier study were not significant in the present double blind replication. Also, the effect of EMF on the number of incorrect answers in the memory task was inconsistent. We previously reported no significant effect of EMF exposure on the number of incorrect answers in the memory task, but a significant increase in errors was observed in the present study. We conclude that EMF effects on the EEG and on the performance on memory tasks may be variable and not easily replicable for unknown reasons.

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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

Population24 normal subjects

Sample size24

ExposureRF · 902 MHz

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

In a double-blind, counterbalanced within-subject design comparing task performance with vs. without exposure to a digital 902 MHz field, the study did not replicate previously reported significant EEG (ERD/ERS) changes; all eight earlier significant changes were not significant here. Effects on memory task errors were inconsistent across studies, with this replication observing a significant increase in errors whereas the earlier study reported no significant effect.

Outcomes measured

EEG event related desynchronization/synchronization (ERD/ERS) in 4-6 Hz, 6-8 Hz, 8-10 Hz, and 10-12 Hz bands during an auditory memory task
Memory task performance (number of incorrect answers)

Limitations

Small sample size (24 subjects)
Replication failed for previously reported EEG effects, suggesting variability and limited reproducibility
Exposure details such as SAR and exposure duration not reported in the abstract

View raw extracted JSON

{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 902,
    "sar_wkg": null,
    "duration": null
  },
  "population": "24 normal subjects",
  "sample_size": 24,
  "outcomes": [
    "EEG event related desynchronization/synchronization (ERD/ERS) in 4-6 Hz, 6-8 Hz, 8-10 Hz, and 10-12 Hz bands during an auditory memory task",
    "Memory task performance (number of incorrect answers)"
  ],
  "main_findings": "In a double-blind, counterbalanced within-subject design comparing task performance with vs. without exposure to a digital 902 MHz field, the study did not replicate previously reported significant EEG (ERD/ERS) changes; all eight earlier significant changes were not significant here. Effects on memory task errors were inconsistent across studies, with this replication observing a significant increase in errors whereas the earlier study reported no significant effect.",
  "effect_direction": "mixed",
  "limitations": [
    "Small sample size (24 subjects)",
    "Replication failed for previously reported EEG effects, suggesting variability and limited reproducibility",
    "Exposure details such as SAR and exposure duration not reported in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "cellular phone",
    "RF EMF",
    "902 MHz",
    "EEG",
    "ERD/ERS",
    "auditory memory task",
    "double blind",
    "replication",
    "cognitive performance"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones",
      "weight": 0.9,
      "reason": "Study tests RF exposure from a cellular phone (902 MHz) and measures EEG and memory task performance."
    }
  ]
}

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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: 10.1002/bem.10143
PubMed: 14696051

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