研究のタイプ: 医学/生物学の研究 (experimental study)

[P600波形の主成分分析:RFおよび性別の効果] med./bio.

Principal component analysis of the P600 waveform: RF and gender effects

掲載誌: Neurosci Lett 2010; 478 (1): 19-23

この研究は、ボランティア実験において、携帯電話から放射されるものと同様のRFの存在下および非存在下で聴覚記憶タスク遂行中の被験者で記録された事象関連電位(ERP)を分析した。39人の健康被験者(男性20人、女性19人)のERPのP600成分の活性化パターンを、主成分分析(PCA)および反復測定ANOVAを用いて分析し、これらのパターンがRFおよび性別に関連する否かを調べた。その結果、P600成分の活性化は、後頭部領域の電極で早期に、より強く発生し、頭部中央領域の電極ではそれより弱くなることが示された;このような傾向は、PCAとANOVAで一致していた;反対に、前頭部領域の電極での活性化は遅れて生じ、強度もかなり低下した;RFがない場合、男性に比べ、女性の被験者では、前頭部電極での低い振幅、中央部電極での短い潜時が有意に示された;このような性別による差は、RF存在下では消失した、と報告している。

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研究目的(著者による)

To study the patterns of activation of the P600 waveform of the event-related potentials (EEG) during a working memory task (digit span test) and whether these patterns are radiofrequency exposure and gender dependent.

詳細情報

The P600 component is related to linguistic processes and working memory.
Two different groups took part in two separate experiments. The first group consisted of 19 healthy subjects (9 men and 10 women). In the second experiment 20 individuals participated (10 men, 10 women). One group was exposed to 900 MHz signal and the other group to 1800 MHz. The subjects performed the memory test (digit span test) 52 times and the duration of one recording was about 45 minutes. Each subject performed the test twice (with and without exposure). Each task started with a warning stimulus signal tone of either low (500 Hz) or high frequency (3000 Hz). At the end of the number sequence presentation, the same tone was repeated and the subjects had to recall the numbers in the same (500 Hz) or in the opposite order (3000 Hz tone).

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 900 MHz
ばく露時間: about 45 min.
ばく露2: 1,800 MHz
ばく露時間: about 45 min.

ばく露1

主たる特性
周波数 900 MHz
タイプ
  • electromagnetic field
ばく露時間 about 45 min.
ばく露装置
ばく露の発生源/構造
Distance between exposed object and exposure source 20 cm
チャンバの詳細 tests performed in a Faraday room
ばく露装置の詳細 dipole antenna fixed near the volunteer's right ear; warning signal and auditory tasks were presented via a non-metallic earphone
Sham exposure A sham exposure was conducted.
パラメータ
測定量 種別 Method Mass 備考
電力 64 mW mean - - -

ばく露2

主たる特性
周波数 1,800 MHz
タイプ
  • electromagnetic field
ばく露時間 about 45 min.
ばく露装置
ばく露の発生源/構造
  • E1と同じ装置
Sham exposure A sham exposure was conducted.
パラメータ
測定量 種別 Method Mass 備考
電力 128 mW mean - - -

ばく露を受けた生物:

方法 影響評価項目/測定パラメータ/方法

研究対象とした生物試料:
研究対象とした臓器系:
調査の時期:
  • ばく露中

研究の主なアウトカム(著者による)

Both principal component analysis and analysis of variance produced congruent results, showing that activation of the P600 component occurs early and more intensely in the region of the posterior EEG electrodes and in a less intense manner in the central electrodes. Conversely, the activation at the anterior electrodes arises later with a considerably reduced intensity.
In the absence of the radiofrequency electromagnetic field female subjects exhibited significantly lower amplitudes at anterior electrodes and earlier latencies at central electrodes than male subjects. These differences disappear under radiofrequency exposure. Thus, the P600 component follows distinct patterns of activation in the anterior, central and posterior brain areas and gender differences are observed simultaneously at several electrodes within these areas.

研究の種別:

研究助成

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