That's closer to the truth. "MOST" performance wheels are designed to offer at least some air circulation at speed. Traditionally, most wheels funnel air from under the car and out of the wheel. That's why so much dust lands on the outside of the wheels, but the inside stays comparatively clean. This also helps add a "little" to down force. As the wheels spin and pull air across the brakes from under the car, it creates a low pressure area. Less air, less pressure, more air flow equals less "lift" at high speeds.

Next time you are watching a Formula 1 or American LeMans race, look at the cars. After a while the cars will be streaked down the side with black brake dust. Sometimes, when they get on the brakes HARD, you can even see the cloud of dust emit from the wheel.

This was all told to me by my Fluid Dynamics Professor at Virginia Tech, so I would assume it to be an accurate description...