Couples at the Tokyo Game Show can try a new app for the iPad that checks if their brain waves are compatible. Brain Kiss uses a headset made by U.S. firm NeuroSky, which has a sensor that sits on the forehead and another that clips on the ear.

(Click to see a video of an actual Brain Kiss.)

The premise is simple. You and your partner put on a Bluetooth headset that reads your brain waves, activate your iPad, then look deep into each other's eyes. After a few seconds, the results come in -- and they don't necessarily match.

In one demonstration, a male spokesman came up as deeply attracted to one of the female attendants at his booth, while her iPad showed "no interest."

New hardware is becoming scarce at the Tokyo Game Show, which features only one of the big three console makers, Sony. Nintendo and Microsoft have focused more on E3, the large game show that runs in California during the summer.