A comparable effect was shown by Herrman and colleagues  for alpha activity: alpha activity was only increased by stimulation with the individual alpha frequency
(IAF) of the subject, when the IAF power had been low beforehand.
Different from the standard alpha band (8-12 Hz), the IAB was between 5.8 and 10.8 Hz and the peak alpha frequency
was 9.5 Hz.
Of note, early stages of AD (even preclinical) are typically associated with slowing down resting occipital alpha rhythms, namely, a decrease of the individual alpha frequency
(IAF) peak in power density .
Early on, when the subjects were just beginning to lose consciousness, the researchers detected an oscillation of brain activity in the low frequency (0.1 to 1 hertz) and alpha frequency
(8 to 12 hertz) bands, in the frontal cortex.
The EEG showed that as patients became less responsive, there was a fluctuation of brain activity in the low frequency and alpha frequency
of the brain - Alpha oscillations peaked when the low-frequency waves were at the lowest point.
Dielectric measurements were carried out using Novocontrol system composed from an Alpha frequency
response analyzer and Quattro temperature controller.
Pulse-modulated EMF exposure enhanced EEG power in the alpha frequency
The highest level of coherence between brain cortical sites--found in the alpha frequency
bands of EEG readings from the posterior occipital lobe--was significantly positively correlated with a larger total size in the corpus callosum, said Dr.
Alpha power depends on the voltage of the EEG signal and in a physiological sense reflects the number of neurons that oscillate synchronously within the alpha frequency
At the left during exposure to the 9.41 Hz signal we see a normal [micro]V (micro volt) amplitude alpha frequency
of 9.45 Hz.
Analysis of the alpha frequency
band for the visual imagery task compared to baseline
Based on the EEG findings of reduced power in middle-range (alpha) frequencies in individuals with autism [23-25, 35], we reasoned that one possible mechanism of tDCS is that it results in an increase in alpha frequency
in the area under the anode, which may reflect an increase in synaptic connectivity, and that this tDCS-related increase in alpha frequency
would be associated with symptom improvement in those who receive tDCS.