Do our brains pay a price for GPS?

Technically speaking, you need to go back to skool and get your initialisms right.

GPS, pronounced Gee Pee Ess, is an initialism, not an acronym. GPS, pronounced Jips, as was suggested in a previous thread, would be an acronym.

NATO (Nay-Toe) is an acronym.
IRS (Eye-Are-Ess) is an initialism.

Although, to be fair, in common usage, the distinction is seldom made.