The John paper 2 | Neuro-patch
This is the second part of a look at an old paper: E. Roy John; The neurophysics of consciousness; Brain Research Reviews, 39, 2002 pp 1-28. It is about brain waves. Some background is needed to understand his model. EEG measures the voltage potentials on the scalp and from these are inferred the voltage potentials on/in the the cortex outer layers. From the changes in these potentials it is possible to look at the underlying waves. The trace is mathematically separated into component waves and these are graphed in separate bands of frequency. The amount of energy in each band is calculated. This is the power spectrum. The conventional bands are: gamma (25-50 cycles per second or Hz), beta (12.5-20), alpha (7.5-12.5), theta (3.5-7.5), delta (1.5-3.5). These fluctuations in potential affect the activity of neurons. The potential across the neuron's membrane has a threshold which allows initiation of an electrical signal to be propagated along the neuron cell and axon. The