To study the effect of electromagnetic fields emitted by cellular phones on the evoked neuronal activity of central nervous system relating to generation of electrodermal activity (an index of sympathetic nervous system activity) and to study the usefulness of electrodermal activity in the asseessment of cellular phone effect on the central nervous system.
Electrodermal activity is a common term for all electrical phenomena in skin and results from eccrine sweat glands activity driven by sympathetic cholinergic neurons.
Patellar tendon stimulation (left or right, to study the effect of brain asymmetry) was used to activate the central nervous system regions (EDA-2) responsible from the generation of electrodermal activity. Electrode arrangements at the palmar region of both hands were used to measure the evoked bilateral electrodermal activity.
Modulation type: pulsed
Exposure duration: continuous for 5 min
|Exposure duration||continuous for 5 min|
|Repetition frequency||217 Hz|
|Chamber||The subjects in a quiet room remained relaxed in the supine position with their eyes closed.|
|Setup||Two identical mobile phones were held close to the ear but not touching the subject's head by an adjustable support. Both phones were powered in standby mode except for planned EMF application. Alert type for the incoming calls was set to quiet mode so that the subjects were unaware whether a call was incoming or not. Common ringing call for five minutes was used.|
|Sham exposure||A sham exposure was conducted.|
|Additional info||Only one of the phones was activated in quiet call mode. There were three different exposure conditions: sham, ipsilateral, and contralateral (to the brain site primarily activated by patellar tendon stimulation) under double-blind conditions.|
No parameters are specified for this exposure.
Under sham exposure the latency of skin resistence response was significantly shorter on the right for right-handed responders. Cellular phone exposure not only affected this asymmetry, but also increased the skin resistence latency approximately 200 ms irrespective of the head site next to mobile phone used.
Because the central nervous system regions including EDA-2 are also involved in tasks of motor timing and time estimation, delayed response in this neuronal network due to cellular phone exposure may increase the response time of mobile phone users. Therefore, the data point to the potential risks of mobile phones on the function of central nervous system and consequently, possible increase in the risk of phone-related driving hazards.