I found this on Digg.

http://www.peak.sfu.ca/the-peak/2005...ue9/ne-mj.html

"The researchers found that rats treated with HU-210 on a regular basis showed neurogenesis — the growth of new brain cells in the hippocampus."

The hippocampus - mainly known for long term memory.

They used it on rats, and state:
“That does not mean that general use in healthy people is beneficial,” said Memorial psychology professor William McKim. “We need to learn if this happens in humans, whether this is useful in healthy people, and whether THC causes it as well.”

They also state "that marijuana disrupts memory and cognition. “These effects can be long-lasting after heavy use,” he said. “This makes it difficult to succeed academically if you use it excessively.”

Then again, you have state-dependant learning...smoke weed and study, smoke weed and take the test!

What do you guys think?