High energy in low frequencies on awake users.

[lsegura003]

Hello,

first of all i am not sure if the term "energy" is the most correct here, so i will clarify that it refers to a normal lecture ^2 at each sample.


in the data i am about to show i was trying to analyse the cerebral activity of a subject in different frequency ranges.

The way i did this, was getting the raw signal (with no filters), and apply 3 different filters to isolate 3 different frequency ranges.

These ranges are : 1-4 Hz, 4-7Hz, 7-50 Hz. The full frequency range considered is 1-50Hz.

To see the precision of the frequencies isolation, i first obtained a graphic with the frequency response (which seemed fairly OK).

Afterwards, i analysed which of this frequency ranges had more energy.

The experiment was made in an awake user.

To my surprise, most of the energy was isolated in 1-4Hz range. I am pretty much doubtful about why this happens, as theorically energy in this frequencies (delta waves) should be low when a subject is awake, or that is what i understood.

Could someone help me with this?

This is the data i can observ:

https://drive.google.com/file/d/0B_zAJF ... sp=sharing