First, you have to realize that what Julian was talking about was only a small part of the AI of the ghosts in PacMan. In fact, it was the "chase" section of code. Each ghost also had an "Idle" or "Search" section of code that was unique to only he/she.

A pretty good overview of how the ghosts "think" is posted at:
http://www.webpacman.com/ghosts.html

For information overload on the topic, check out:
http://home.comcast.net/~jpittman2/p...andossier.html

The scent by the way is VERY limited and "evaporates" quickly, thus even in the case of the 90 deg corners it is virtually imposable to get a scent trail confusion. Of course, there are ways to do it, and these are "break zones" in the game that many advanced players will make use of simply to get a break (if you go to them under the right circumstances the ghosts will NEVER come find you).

- Jeremy