People who are new to meditation sometimes complain that they find it too difficult to silence their thoughts. This is perfectly normal and in fact, if you are new to meditation you should not expect to achieve absolute mental silence in the next day or two. Even the most experience meditators still have their good days and bad days when it comes to meditation and a certain amount of mental activity during meditation is quite normal.
Neural oscillations are rhythmic or repetitive electrochemical activity in the brain and central nervous system. Such oscillations can be characterized by their frequency, amplitude and phase. Neural tissue can generate oscillatory activity driven by mechanisms within individual neurons, as well as by interactions between them. They may also adjust frequency to synchronize with the periodic vibration of external acoustic or visual stimuli.