*1.3.6 The flow of EEG Waves*

The amplitude of EEG signals is very closely related to the level of consciousness of a person [9]. An example of these waves is shown below in **Figure 6**.

From **Figure 6**, the conclusion is drawn that the slow waves Theta and Delta occur in the third and fourth stages of human sleep. The awake condition presents a high level of consciousness with Beta waves. This 90 minutes of the cycle is repeated the whole night with repeated EEG wave activity.
