posted on 2014-09-03, 10:20authored byChing-Sui Hung
This study employed multiple .assessments, including sleep/resting waking EEG
(visual scoring and power spectral analysis) and psychomotor vigilance task, to
access effects of varying pulse-modulated microwaves (such as: 'talk', 'listen' and
'standby' mode signals) emitted from a standard mobile phone. The idea was
prompted by a finding that the pulse modulation frequencies of mobile phone signals
correspond to the frequencies of brain delta and alpha waves. Thereby it is possible
the brain is able to recognize and respond to the low-frequency components of the
mobile phone signals. Supporting evidence comes from repetitively reported EEG
alpha and spindle effects of the 2, 8 and 217-Hz pulsed microwave exposure.
Furthermore, brain imaging (EEG and PET) stUdies reveal 'Iow-frequency pulsemodulated
waves' rather than the 'microwave frequency carrier waves' is the sine qua
non for inducing these brain physiological effects [Huber et al., 2002, 2005; Regel et
aI., 2007a]. On the other hand, recent converging evidence, from molecular,
behavioural and electrophysiological level, have shown that brain plasticity is a
continuous process from waking to sleep and, sleep, a well-defined physiological
condition, is 'shaped' by the waking experiences. The latter findings suggest certain
sleep EEG features may characterize levels of cortical plasticity during wakefulness.
The work presented in this thesis was inspired by these studies and aimed to
understand how the real mobile phone Signals with different low-frequency pulsing
components [such as 'talk' (8, 217 Hz pulsed), 'listen' (2, 8, 217 Hz pulsed) and
'stand by' mode « 2 Hz pulsed)] change human brain electrical activities from waking
to sleep. We approached this question based on EEG analysis in two domains: (1)
EEG visual scoring; (2) EEG spectral analysis from relaxed waking to the deeper
stages of non-NREM sleep. We also looked at the effects on the psychomotor
vigilance performance. Results suggest 'talk' and 'Iisten/standby' modes have inverse
effects on the distinctive thalamo-cortical oscillation modes and may thus impart
inverse effects on their sleep structures. The implications of this study are of practical
importance as it suggests the thalamo-cortical oscillations can be modulated by
synchronizing rTMS/tDCS/DBS and sleeplwaking EEG. This concept may be applied
to modulate the brain oscillation modes for enhancing sleep-dependent brain plastiCity
or information processing.
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Publication date
2008
Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.