Some people are aware of physical sensations in their brain when they meditate, others are not. Don’t worry about what you feel or don’t feel. Many times, what you expect to happen, will happen - it’s a proven fact that scientists can influence the results of an experiment with the energy of their own expectations!
If you do feel a physical sensation or even a shift in your emotions, it’s because of heightened awareness.
When you’re awake, your brain constantly cycles in and out of the four brainwave states, sometimes for microseconds, sometimes for longer. When you’re busy doing things, you are usually not aware of any physical sensations in the brain as its activity levels fluctuate.
But when you meditate, you have less distractions, and it’s easier to become aware of any subtle sensations in your brain and body. This is why many people believe that these sensations only happen during meditation, when in fact they’re happening all the time - you’re just not aware of them when you’re busy.
Meditation has a funny way of distorting your perception of time and space, of relaxing you so deeply that you lose awareness of your physical body. This is a very interesting experience!
You may ‘feel’ an inter-connectedness with everything. You may perceive yourself as nothing but energy. Or, you may be very aware of the your leg having gone to sleep... what’s important is that you’re developing your awareness.