Human brain can process more information than
their five senses.
Case 1:
When one is sitting in a room listening to a speech/talk, sometimes your mind can wonder to some distant places. Or you can critically asked your self questions and anticipate every sentences that the speaker going to say. Being a critical listener.
Your ear, one of human sense, is operating slower than your brain.
Case 2:
If the speech become too mundane, one finds no need to focus 100% to listen to the speech. Hence, he let his brain wonders further. In the end, nothing get to your brain because u r not paying attention.
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Just like the speech analogy, oem nav is designed in such way not to be able to be operated during vehicle operation i.e only when the car is at stop. The argument is: for a normal person with normal IQ, spliting the focus between observing the road and observing the nav screen is still consider safe (within their human brain and senses processing power). There was lots of study on this ergonomics design circa 1990s. I got a friend who got a phd in nav and vehicle console design.
Now, if you do beyond that, to operate the nav + drive simult or even to watch a dvd + drive, it goes beyond the normal human brain and therefore goes beyond oem intended-design.
It is still safe for some drivers, but maybe not for most drivers.
Some people got a better hand-eye coordinations.
Some people dont. Admit it,
Why donald trump get to marry a sexy model?
Because not eveyone is created equal. Yes, life is unfair
