COST B27 ENOC Joint WGs
Meeting
Swansea UK, 16-18 September
2006
Bazanova Olga M.
Aftanas Lubomir I.
Analysis individual EEG alpha activity
peculiarities for enhancement
Neurofeedback efficiency
State-Research Inst. Molecular Biology & Biophysics, State-Research Inst. Physiology,
Siberian Branch, Russian Academy of Medical Sciences
1
Neurofeedback efficiency runs up to no more
than 75 % (Monastra et al., 2005)
 Possible reasons for NFT inefficiency:
 the objective assessment of the neural
organization in a given patient was not
used
 the neurotherapy protocols were not
individualized
(Thatcher et al, 1983; Kaiser, 2001; Monastra et al 2005; John ER&
Prichep, 2006 )
2
4-8 Hz may be theta for some and
alpha for others. (Kaiser D.,2001)
Θ α?
α-1? α-2?
3
…only the alpha “atom” had a
significant temporal correlation
with the fMRI signal
Martı´nez-Montes Eduardo, Valde´s-Sosa Pedro A, Miwakeichi, Fumikazu,
Goldman Robin I., and Cohen Mark S. (2004). Concurrent EEG/fMRI analysis by
multiway Partial Least Squares. NeuroImage, 22, 1023–1034
4
Alpha rhythm

The oscillations in electric potential within the
8- to 12-Hz range, normally recorded as
sinusoidal waves with larger
amplitudes over posterior regions

during eyes-closed rest.
The rhythm that diminishes when eyes are
opened or during mental activity.
(Berger, 1929; Cooper et al., 1965; Pfurtscheller et al., 1996;
5
Nunez et al., 2001;).
IAPF – individual alpha peak frequency - predictor of
cognitive capacities
<10 Hz – poorer
academic performance
>10 Hz – better
academic performance
6
(Jausovec (1996); Basar et al., 1997a; Giannitrapini (1969);
Klimesch et al. (e.g. 1996, 1999) Klimesh and Doppelmayr (1998),
IAPF depends on age
Clarck, 2001
(Mankovskiy and Belonog,1971; Roubicek, 1977 Epstein 1980; Li et al., 1996; Osaka
7
et al., 1999),
IAPF depends on menstrual cycle stage
Individual
Alpha peak
frequency
8
( Creiutzfield et al.,1980,1982,1988; Bazanova et al.,2004)
What is alpha frequency range?
Kaplan, 2001,2003; Ray & Cole, 1985.
Jensen et al 2002; Kilner, 2005;
Martinez et al2004; de Toffel & Autret,
1991;
P.Etevenon et al, 1990; Moretti et al
2004
9
Alpha- α, theta- Θ, beta- β
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Alpha rhythm
1.
The oscillations in electric potential within the 8- to 12Hz range, normally recorded as sinusoidal waves with
larger amplitudes over posterior regions during eyesclosed rest.
2. The rhythm that diminishes when
eyes are opened or during mental
activity.
(Berger, 1929; Cooper et al., 1965; Pfurtscheller et al., 1996;
11
Nunez et al., 2001;).
Alpha-1 may be theta for some and alpha
for others.
Eyes open
Eyes closed
alpha activity
12
Alpha-2 may be beta for some and
alpha for others.
Eyes
open
Θ
Eyes closed
α
β
alpha activity
8-12 Hz
13
Alpha- α, theta- Θ, beta- β
Eyes open
Θ
α
Eyes closed
α
β
alpha activity
14
INDIVIDUAL ALPHA BAND WIDTH
Eyes open
Eyes closed
alpha activity
rhythm that diminishes when eyes are opened
or during mental activity = “Berger Effect”.
15
IAAS - Individual amount of alpha
suppression
(Koukkou 1980, 1982; Koukkou et al. 1982, 1991; Koukkou and Lehmann 1987;
Schmelkina,1998; Kolev et al. 2002)
16
IAAS - Individual amount of alpha
suppression
children,
old people
adults
(Smelkina R1998; Larkina and Kirenskaya 2005).
17
IAAS - Individual amount of alpha
suppression
normals
remitted
schizophrenics
Acute
schizophrenics
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(Koukkou 1980, 1982; Koukkou et al. 1982, 1991; Koukkou and Lehmann 1987)
Alpha peculiarities
Eyes open
Eyes closed
alpha activity
19
The main objective
to demonstrate efficiency of
Neurofeedback when individual EEG
alpha activity parameters are in use
20
Methods.
Patients
patient C.- 7 year
patient A. - 50 year
schoolboy
ADHD
professional musician
functional contracture
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Methods.
Procedure
22
Methods.
Reducing Θ/β - neurofeedback
Cz
Controlled parameter
23
Methods.
Alpha-EEG/EMG-Biofeedback
24
Methods.
EEG recording
F3
C3
P3
O1
F4
θ/β
C4
Cz
P4
α
O2
25
Methods.
Alpha activity EEG analysis
eyes closed condition
for IAPF
eyes open vs eyes
closed condition
for IABW and IAAS
26
Methods. Alpha activity EEG analysis
individual alpha band width (IABW)
oe- open eyes
ce- closed eyes
 Poweroe -Powerce 

%
Powerce


Cut-off criteria = 20%
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Methods. Alpha activity EEG analysis.
Individual alpha band width (IABW)
Eyes
open
Eyes closed
alpha activity
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Methods. Alpha activity EEG analysis:
individual amount of alpha suppression (IAAS)
 Poweroe -Powerce 

%
Powerce


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Results.
Baseline individual alpha activity peculiarities
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Results.
Standard ranges Alpha-EEG/EMG Biofeedback
SNFB
Baseline condition
EMG
Post SNFB
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.Results
Individual ranges Alpha-EEG/EMG Biofeedback
INFB
EMG
Baseline condition
Post INFB
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Results.
Standard ranges θ/β reducing Neurofeedback
SNFB
SNFB
- ST performance
duration
-Reading words per
minute
33
Results.
Individual ranges θ/β reducing Neurofeedback
INFB
INFB
- ST performance
duration
-Reading words/
minute
34
Similarities
1. The SNFB training had aggravated patients conditions along
both electrophysiological (depression of alpha power, narrow
IABW, weak IAAS, increased EMG), and behavioral domains.
2. The INFB training had increased alpha activity indices and
was associated with subjective feelings of relaxation,
emotional calm and centeredness
35
In the present research, due to the
individual frequency EEG analysis, the
necessity of an individualization of the
approaches for Neurofeedback
technology is convincingly shown
36
Thank you kindly
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