So if faces are so important to human beings, why exclude them from videos? Because they are a powerful distraction from the concepts being discussed. What, after all, is more distracting than a pair of blinking human eyes, a nose that twitches, and a mouth that moves with every word? Put a face in the same frame as an equation, and the eye will bounce back and forth between the two. Concentration will wander. Haven’t we all had the experience of losing the thread of a conversation because we homed in on the features of the person we were talking with rather than paying steady attention to
...more
