When you multitask you do a mediocre job of each, or worse. Think of the times you were doing email while on a conference call. No one could see you so you thought no one would notice; until, the boss calls out your name with, “what do think of that?”
Oh, oh! Now you have to admit you weren’t paying attention. Now you need to ask your boss for a ‘do over.’
To keep your focus on the meeting you might try listening so hard you are paying attention to the meaning, not just the words.
Or you can mind map the subjects during the meeting.
For sure, you don’t want to be thinking about what you will say when it is your turn. That, too, will mean you won’t be able to answer the boss’s question.