Re: hi pete and group; link referece

[Guest guest]

Erez,When you train using monopolar montages (using ears or mastoids as references), you are training the difference between the active site and the reference site.  You assume that earlobes or mastoid bones have no signal, so the signal is whatever it is (for example) at F3 minus zero.  The problem is that there actually IS a small signal at A1 or M1. You are measuring the field from the temporal lobes, and the temporal lobes are more likely than most other homologous sites to be quite different due to injuries, different functions, etc.  So when you are training coherence, synchrony or symmetry, or gathering data for an assessment, where the relationship between the two sites is important, different signals at the temporals can lead to different values at the references.  Imagine that F3 and F4 each have a value of 8u, but A1 is 0.5u and A2 is 1.0 because of different activities in the temporal lobes.  When the amplifier subtracts to give the differential signals, it will show F3 as (8-0.5) 7.5u and F4 as 8-1) 7u.  Obviously you are getting incorrect information--F3 appears greater than F4, when they are in fact the same.

By linking the ear references, you create a single reference value which is used for both sites, and the comparative values will be correct.When you train amplitude, you are training one variable--how much alpha (for example) is being produced.  

When you train percent amplitude, you are training two variables--how much alpha is being produced vs. how much of all frequencies are being  produced.The only way to make alpha amplitude go up is to increase the number of neurons firing in the alpha frequency or increase the synchrony among those neurons firing in alpha.

You can increase alpha percent by reducing beta or delta or theta or any combination of other frequencies--even if actual alpha levels are going down!  If alpha is 8u and the total EEG is 40, alpha percent is 20%.  If you train and overall EEG goes down to 28u and alpha goes down to 7u, alpha percent will be 25%.

The problem with training percent is that you are putting two values into one number, and it's very difficult to tell what's really happening.  Also, because the numerator and denominator may go in opposite directions, the percent value can be very unstable, bouncing around a lot.  I now train percent by inhibiting squash (2-38 Hz) and rewarding whatever band I want more of.  I can see which, if either, is going the direction I wish and adjust the thresholds to push one a little more than the other, etc.  In many cases, using the Options designs in the TLC package, I can track whatever frequency is high--even if the band changes during the session--and focus on reducing that instead of the whole band--or in addition to the whole band.

Pete-- Van Deusenpvdtlc@...http://www.brain-trainer.com

USA 678 224 5895BR 47 3346 6235The Learning Curve, Inc.

On Sun, May 20, 2012 at 12:53 PM, Erez <erez1333@...> wrote:

 

hi

i wonder what is the different between training link ears vs.say

f3a1-f4a2

2. you explain it to before but i still can grasp it

what i s the diffrent by trainig percent vs/ trainig amplitude

what are the benefit of each method

and when it eill be wise to choose one or the anther?

thx for your great answers

erez