title: Using the nonlinear control of anaesthesia-induced hypersensitivity of EEG at burst suppression level to test the effects of radiofrequency radiation on brain function.
abstract: BACKGROUND
  In this study, investigating the effects of mobile phone radiation on test animals, eleven pigs were anaesthetised to the level where burst-suppression pattern appears in the electroencephalogram (EEG). At this level of anaesthesia both human subjects and animals show high sensitivity to external stimuli which produce EEG bursts during suppression. The burst-suppression phenomenon represents a nonlinear control system, where low-amplitude EEG abruptly switches to very high amplitude bursts. This switching can be triggered by very minor stimuli and the phenomenon has been described as hypersensitivity. To test if also radio frequency (RF) stimulation can trigger this nonlinear control, the animals were exposed to pulse modulated signal of a GSM mobile phone at 890 MHz. In the first phase of the experiment electromagnetic field (EMF) stimulation was randomly switched on and off and the relation between EEG bursts and EMF stimulation onsets and endpoints were studied. In the second phase a continuous RF stimulation at 31 W/kg was applied for 10 minutes. The ECG, the EEG, and the subcutaneous temperature were recorded.
  
  
  RESULTS
  No correlation between the exposure and the EEG burst occurrences was observed in phase I measurements. No significant changes were observed in the EEG activity of the pigs during phase II measurements although several EEG signal analysis methods were applied. The temperature measured subcutaneously from the pigs' head increased by 1.6 degrees C and the heart rate by 14.2 bpm on the average during the 10 min exposure periods.
  
  
  CONCLUSIONS
  The hypothesis that RF radiation would produce sensory stimulation of somatosensory, auditory or visual system or directly affect the brain so as to produce EEG bursts during suppression was not confirmed.
authors.affiliation: Tampere University of Technology, Pori, Finland. tarmo.lipping@tut.fi.
authors.forename: Tarmo
authors.initials: T
authors.lastname: Lipping
authors.forename: Michael
authors.initials: M
authors.lastname: Rorarius
authors.forename: Ville
authors.initials: V
authors.lastname: Jäntti
authors.forename: Kari
authors.initials: K
authors.lastname: Annala
authors.forename: Ari
authors.initials: A
authors.lastname: Mennander
authors.forename: Rain
authors.initials: R
authors.lastname: Ferenets
authors.forename: Tommi
authors.initials: T
authors.lastname: Toivonen
authors.forename: Tim
authors.initials: T
authors.lastname: Toivo
authors.forename: Alpo
authors.initials: A
authors.lastname: Värri
authors.forename: Leena
authors.initials: L
authors.lastname: Korpinen