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| Up: BioMedia CogniVideo Settings Next Topic: CogniVideo Video Mode |
Values changed in this pane are updated immediately in the device. You will need to exit the
field to get the device to update.
The video can gradually change from completely clear (unmodified) to completely black, gradually changing from clear to black. This is different from the FMP device which fully pauses the DVD.
Each video frame occurs at a rate of 60 per second, or about 17ms per frame. This is beyond what the human eye can perceive, making television appear to be continuous movement. However, using the CogniVideo device, we can affect each frame if we want to. The High Freq. Delta is the amount of change at this highest rate.
The low frequency settings determine slower changes in the Control Value based on the subject's adherence to the desired state.
To fully explain how these parameters interact, they will first be described. Then some examples will be presented.
In operation, if sound is heard or switch is on for at least the Reward Level Percentage of the time during the last Window, then the Control Value will be reduced (screen is clearer). If sound is heard or switch is on for less than the Penalty Level Percentage of the time during the last Window, then the Control Value will be increased (screen is less clear). Otherwise, the low frequency control value will remain the same.Window Size (x 1/60s)
This sets the size of the window that is used to determine the Low-frequency changes. The default is 60, or one second. The maximum setting is 255, or about 4.25 seconds.Reward Level %
If Sound or Switch is detected for at least this percentage of the time, then the Control Value will decrease by 1, making the screen slightly clearer. The default is 80%. The Reward Level Percentage cannot be less than the Penalty Level Percentage.Penalty Level %
If Sound or Switch is detected for at no more than this percentage of the time, then the Control Value will increase by 1, making the screen slightly darker. The default is 20%. The Reward Level Percentage cannot be less than the Penalty Level Percentage.
If you wish to disable the high-frequency setting and the windowing changes, simply set the High Freq. Delta to zero and set the Reward Level and Penalty Level to 50%.
Then, over the last second, the CogniVideo device measures how much sound or switch was detected. If it was detected at least 80% of the time, then the High, Freq. Delta would be subtracted from the currnt Control value. If it was detexted no more than 20% of the time, then the Control Value is decreased, (i.e. clearer) for then next period. Let's assume sound was detected 90% of that second. This is over the Reward Level and therefore, the internal Control value is decreased. During the next second, the Control Value will be 7 flickering to 8.
If you wish to take advantage of the extremely fast response of the CogniVideo system, you need to eliminate all windowing within your Biofeedback analysis software. Whenever the subject meets your criteria, signal immediately. As soon as the subject does not meet the criteria, then signal the other way. Do not wait for say, 0.5 second and then signal. It is best if we can hear the blow-by-blow response.
| Up: BioMedia CogniVideo Settings Next Topic: CogniVideo Video Mode |
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