I apoligise in advance for posting another question like this. I realise it must get quite irritating. Anyhow, to get to the point, I'd like to know how to to the effect seen multiple times in the attached video, where an object of area of the video flashes. I know it's probably really obvious, but I've tried all the lighting effects in Vegas in combination with masks, and none of them look as good. if anyone could tell me how to do it properly, I would be most grateful.
http://www.youtube.com/watch?v=r029Ao-B ??? 3&index=82
Example of the effect are at 0:14, 0:25, 0:29 and 1:00
Thanks again in advance

