When subjects were looking at something funny, the first thing that happen was that two regions in their left hemispheres lit up. From previous studies these regions are known to be associated with resolving ambiguity. Is there something in “getting it” that’s related to the process by which we work with unclear information until we suddenly see the pattern in it? A couple seconds later two other brain regions became active, called the insula and the amygdala. The insula is associated with emotion, so it seems likely that this is the brain feeling good when it gets the joke–the “ha-ha” response. The amygdala is associated with memory formation. As the researchers point out, while you may not be able to remember every plot detail in a Seinfeld episode, you can probably remember the jokes. Humor stays with us, forming a lasting memory.