While fully thinking?
Whales and dolphins have a quite suprising ability. We know that whales breath using lungs. They must constantly float upwards to the surface for them to breath. There arises a question as to how they sleep. They turn out to sleep using one brain while the other is fully awake!
Can you meditate while thinking? The answer is the same as the one to the question of if you can sing while playing a guitar. It is a coffee time to a beginner but a nobrainer to an expert. How can an acrobat juggle four objects all at once while at the same time riding a unicycle along a rope?
The answer is that we are realy not one in our skulls. There are many of us! Or if you like, our brains have many parts and each can meditate in turn! You can try this by meditating partially. Let us say you are thinking about your bank account while at the same time you are thinking about whales. When you stop thinking about the bank account, you have begun meditating with respect to bank accounts but you are stilly thinking with respect to whales. So you are meditating while thinking all at once!