“Lumosity” or “Luminosity?”

It’s apparently “Lumosity,” a service offering computer-games to supposedly improve brain-function.
I Googled “Luminosity” and it directed to the measure of brightness.
I’ve heard both pronunciations.
Garrison Keillor says “Lumosity” — which is correct —  not “Luminosity.” (“Lumosity” is one of the legitimate sponsors of his radio-program, “Prairie Home Companion,” Another advertiser is Ford.)
As opposed to made-up sponsors, like “American Duct-Tape Council,” or “Ketchup Advisory Board.”
Or “Association of Associations,” or “Professional Organization of English-Majors” (P.O.E.M.).
Garrison may be right, but we all know he’s one a’ them despicable fancy-dan liberals. Such people are always WRONG.
Unless you’re a bellicose, tub-thumping Conservative, for whom spelling errors don’t matter.
It’s the old Rush Limbaugh waazoo. Factuality and truth don’t matter as much as whether it sticks.
The supermarket tabloids tried mightily to make it look like Laura was gonna leave Dubya. But it never stuck.
I get occasional video-ads for “Lumosity.”
In one a chipper cutie bubbles about how it keeps her brain in top shape.
As if she needed it. She looks about 30. —She pronounces it “Luminosity,”or so it seems.
In another ad an actor posing as a retiree pronounces it “Lumosity.” —Or maybe “Luminosity.” Maybe the girl pronounced it “Lumosity;” it’s hard to tell.
This retiree wannabee looks about 40. His hair isn’t even gray yet.
Ever notice how the silver-haired actors hired by AARP, etc. always have a full head of hair?
Never are these actors fat balding geezers.
Makes you wonder if John Kerry wears a toupee?
That would-be retiree pronounces it “Lumosity.”
I get both pronunciations in Lumosity’s advertising.
So maybe Lumosity is run by Conservatives, in which case erroneous pronunciation doesn’t matter.
Our language is becoming stupendously imprecise. In the text world “to” becomes “2.”