Preece A W, Wesnes K A, Iwi G R
Department of Medical Physics and Bioengineering, Bristol Oncology Centre, UK.
Int J Radiat Biol. 1998 Oct;74(4):463-70. doi: 10.1080/095530098141339.
To examine whether the power frequency magnetic field of 0.6mT applied to humans has an effect on cognitive function as has been suggested by animal studies. These fields are less than the suggested intervention level in the UK of 1.6mT and are similar to those found close to some domestic appliances.
A randomized three-way cross-over design using a battery of computerized cognitive function tests were used in the presence or absence of a 50Hz or static magnetic field. Sixteen healthy volunteers undertook two training and three test sessions with a 50Hz or static 0.6 mT magnetic field from a set of coils centred on the head.
In response to the 50 Hz field, disruptions of accuracy were seen from an attentional task (the ability to correctly recognize words shown 20min previously and the ability to maintain a string of digits in working memory). There was no similar response to comparable levels of static magnetic field.
These tests indicated at least temporary deterioration in attention, and working and secondary memory performance while a 50 Hz field is applied. There were no adverse effects on speed from any of the tasks. It was not possible in this study to be sure if these effects were persistent.
动物研究表明，施加于人体的0.6mT工频磁场会对认知功能产生影响，本研究旨在对此进行验证。这些磁场强度低于英国建议的1.6mT干预水平，且与一些家用电器附近的磁场强度相似。
采用随机三向交叉设计，在有或无50Hz或静磁场的情况下，使用一系列计算机化认知功能测试。16名健康志愿者在头部周围放置一组线圈，接受了两次训练和三次测试，测试磁场为50Hz或0.6mT静磁场。
在50Hz磁场作用下，一项注意力任务（正确识别20分钟前显示的单词的能力以及在工作记忆中保持一串数字的能力）的准确性受到干扰。对于同等强度的静磁场，未观察到类似反应。
这些测试表明，在施加50Hz磁场时，注意力、工作记忆和次级记忆表现至少会暂时下降。所有任务的速度均未受到不利影响。在本研究中，无法确定这些影响是否持续存在。
