You may have read not long ago about birds that can plan for the future. The occasion was a paper that came out in the journal Nature detailing some experiments on scrub jays. I found the paper fascinating, not just for the results themselves, but for the many other studies on mental time travel that are going on these days dealing with other animals–rats, pigeons, monkeys, and us. Instead of simply reporting on one experiment, I took some extra time and took a survey of the past and future of mental time travel. It appears in tomorrow’s New York Times.

For those who crave more, here are some key papers behind the story:

**Scrub jays and foresight

**Rats and episodic memories

**Monkeys and foresight

**Episodic memory in humans

**The evolution of foresight in humans (pdf, in review)

**Brain scans linking past and future (pdf

Originally published April 2, 2007. Copyright 2007 Carl Zimmer.