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15~20 billion neurons are making neuronal network connections with synaptic
switches. Different emotional states correspond to different synaptic switching
configurations (SSC), hence different electric current paths in the networks.
The cross-correlation coefficients among EEG signals picked up with scalp
electrodes are influenced by the SSC. After a number of trials we have
found the optimal number of electrodes of ten, with which we obtain 45
cross-correlation coefficients in every 5 seconds because 10C2 = 45. These 45 coefficients are calculated for each of the theta (5~8
Hz), alpha (8~13 Hz) and beta (13~20 Hz) frequency bands, resulting totally
in 135 coefficients forming a 135-D EEG state vector. Then the emotion
matrix is defined so that it, when operating on the 135-D EEG state vector,
results in the 4-D emotion vector (e1, e2, e3, e4) where the four components represent levels of stress, joy, depression,
and relaxation, respectively. When one is in a purely stress state, the
4-D emotion vector will look like (e1, 0, 0, 0); if one feels joy, this vector will look like (0, e2, 0, 0), and so on. As far as we have examined we can separate at best
four orthogonal emotional components even if we introduce a larger number
of electrodes.
Fig.1 is an example of the emotion spectrum when
a young man is listening to Mozart's Eine kleine Nachtmusik which he loves and then to another music he is not interested in so much.
Remarkable difference is in stress and relaxation. The bottom trace of Fig.1 refers to the mental concentration which is
derivable from a different mathematical manipulation.
Typical examples of ESAM application are the following.
| 1) |
Optimizing a color design of automobiles for a target generation and sex. |
| 2) |
Quality of sleep after lunch is best for 15~20 min. |
| 3) |
Users' satisfaction for new products. |
| 4) |
Evaluation of city landscape. |
| 5) |
Most appropriate color conditioning of the room to a client. |
| 6) |
Communication with ALS patients in the final stage (the emotion matrix
is prepared for each patient separating two mental states referring to
"yes" and "no".). |
| 7) |
Finding the most favorite tasks given to retarded children to effectively
activate their brain activity (simultaneous appearance of strong stress and joy means existence of strong curiosity). |
| 8) |
Finding the best-fitting job among many others (principle is in finding
a task to which a subject shows strong stress accompanied by joy). |
| 9) |
The emotion vector of autistic children is found to be frozen on the joy-relaxation plane, and this freezing state is not influenced by the external mental
stimulation. After treatment of years the emotion vector makes a response
to the external mental stimulation. |
| 10) |
This technique gave evidence that our brain catches acoustic sound beyond
20 kHz.This experiment was done for confirmation of superior quality of
the one-bit audio system commercialized by Sharp to the ordinary CD-based
audio systems. In their new machine, acoustic frequency of reproduced music
sounds extend to as high as 100 kHz. When one listens to music sound reproduced
with this system, mental stress level is reduced and joy (satisfaction)
level is significantly increased statistically as compared with the corresponding
music sound reproduced by the ordinary CD-based machine. In other words,
the brain hears sounds beyond the audible frequency limitation. This experiment
gave scientific evidence to our experience that analogue LP sounds are
better than digital CD sounds of music. |
|
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| Ref: T. Musha, Y. Terasaki, H.A. Haque and G.A. Ivanitsky, "Feature extraction
from EEG associated with emotions" (Invited Paper) Art. Life Robotics
(1997) 1:15-19 |
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