Browsing by Author "Wood, A W"
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- ItemThe effect of mobile phone electromagnetic fields on the alpha rhythm of human electroencephalogram.(2007-12-24) Croft, R J; Hamblin, D L; Spong, J; Wood, A W; McKenzie, R J; Stough, CMobile phones MP emit low level electromagnetic fields that have been reported to affect neural function in humans however demonstrations of such effects have not been conclusive The purpose of the present study was to test one of the strongest findings in the literature that of increased alpha power in response to MP type radiation Healthy participants N 120 were tested using a double blind counterbalanced crossover design with each receiving a 30 min Active and a 30 min Sham Exposure 1 week apart while electroencephalogram EEG data were recorded Resting alpha power 8 12 Hz was then derived as a function of time for periods both during and following exposure Non parametric analyses were employed as data could not be normalized Previous reports of an overall alpha power enhancement during the MP exposure were confirmed relative to Sham with this effect larger at ipsilateral than contralateral sites over posterior regions No overall change to alpha power was observed following exposure cessation however there was less alpha power contralateral to the exposure source during this period relative to ipsilateral Employing a strong methodology the current findings support previous research that has reported an effect of MP exposure on EEG alpha power
- ItemHow dangerous are mobile phones, transmission masts, and electricity pylons?(2006-03-22) Wood, A WElectrical power and mobile communications deliver enormous benefit to society but there are concerns whether the electric and magnetic field EMF emissions associated with the delivery of this benefit are linked to cancer or other health hazards This article reviews the strength of the available epidemiological and laboratory evidence and notes that this falls short of what is normally required to establish a causal link However because of scientific uncertainty a cautious approach is often advocated but here too there may be a tendency to judge these risks more harshly than those in other areas with similar strength of evidence
- ItemThe sensitivity of human event-related potentials and reaction time to mobile phone emitted electromagnetic fields.(2006-04-12) Hamblin, D L; Croft, R J; Wood, A W; Stough, C; Spong, JThere is some evidence to suggest that exposure to mobile phones MPs can affect neural activity particularly in response to auditory stimuli The current investigation n 120 aimed to test recent findings in this area namely that N100 amplitude and latency would decrease and that P300 latency and reaction time RT would increase under active relative to sham exposure during an auditory task Visual measures were also explored A double blind counterbalanced crossover design was employed where subjects attended two sessions 1 week apart In both sessions participants 1 performed auditory and visual oddball tasks while electroencephalogram EEG was recorded with a MP set to sham exposure mounted over the temporal region and 2 performed the same tasks while the handset was set to active sham When active the MP transmitted for 30 min at 895 MHz average power 250 mW pulse modulated at 217 Hz average SAR 0 11 W kg Paired t tests compared difference scores from the sham sham session to those from the sham active condition The study was designed to detect differences of 1 4 of a standard deviation with a power of 0 80 There was no significant difference between exposure conditions for any auditory or visual event related potential ERP component or RT As previous positive findings were not replicated it was concluded that there is currently no evidence that acute MP exposure affects these indices of brain activity
- ItemThe use of a 'phantom scalp' to assess the possible direct pickup of mobile phone handset emissions by electroencephalogram electrode leads.(2003-08-01) Wood, A W; Hamblin, D L; Croft, R JA Phantom Scalp was constructed from a conducting foam mat to form a layer under a 62 electrode electroencephalogram cap closely approximating the electrical properties of a human scalp The mat was placed over a polystyrene manikin head to preserve a correct anatomical arrangement Electrical signals were recorded with a Global System for Mobile GSM communications mobile phone handset in place against the side of the head Amplitude spectra were compared for three phone conditions off standby and transmit At 217 Hz significant differences were obtained between transmit and the other two conditions but no significant differences were noted for the physiologically important range 0 5 30 Hz An anomalous difference was noted for one electrode in the range 30 45 Hz