Wynton,

I think it just feels like that is going on because their cards are face down and you'd like to believe something else is happening to cause this noticable trend.

If you take a game like blackjack (or flipping coins) for instance, this is very similar to acknowledging streaks in those games. The streaks aren't completely abnormal, but they aren't as normal as a back and forth breakeven stretch. It's human nature to dismiss the more normal occurrences and remember unusual ones.

When emotions are involved (as they are in poker and the way people play their hands sometimes), being a good hand reader is even more important that just being an EV statistician. There are betting patterns for every player. Tilt does reside in people and is much more evident in the weaker willed. However, there is no such thing as a cut-and-dry "rhythm" that is irrespective of a player's holdings.

I realize that there are times that you can just "know" that a player will raise you on the turn, and they do. There are also times when you are wrong and they either call or fold. It's our nature to ignore the times we are wrong and remember the times we are right. If a such rhythms existed, there would be no uncertainty and our opponents would conduct themselves according to the rhythm 100% of the time irregardless of the board and/or their hole cards.