Tuesday, April 10, 2007

Do animals experience past and future?

Carl Zimmer writes a nice piece in the 4/3 NYTimes on "Time in the Animal Mind" (PDF HERE).

Legend: Scrub jays, left, seem able to plan for the future in experiments, hiding today’s pine nuts for tomorrow’s breakfast. Squirrel monkeys also seem to think about future consequences, while hummingbirds seem to recall time and location of visits to flowers, and rats to remember where they encountered food in a maze. (Credits: from left, Adam Jones/Photo Researchers; Luke MacGregor/Reuters; Esteban Felix/Associated Press; Will & Deni McIntyre/Photo Researchers)

The animals shown in the figure have been shown to have impressive powers of memory, but this doesn't have to imply having a sense of memory or self, i.e. 'thinking about' past or future.

Some argue that mental time travel is distinctive to hominids. Humans can remember events long past and envision the future, and recent experiments by Schacter's lab at Harvard have shown that brain areas involved in episodic memory become active also when people think of themselves in the future.

What about animal's sense of the future? Can they plan ahead? Nicola, Univ. of Cambridge, has done interesting experiments showing sophisticated memory in scrub jays, and she

"recently tested her scrub jays for foresight. She and her colleagues put the birds in three adjoining compartments for six days. Each morning the birds were shut for two hours in one of two rooms. In one room they got nothing to eat. In the other room, they got powdered pine nuts (the scrub jays can eat the powder, but they cannot cache it). For the rest of the day, each bird could move around all three rooms and enjoy more powdered nuts.

On the seventh day, the scientists switched the powdered pine nuts with real ones. If the birds were so inclined, they could cache the pine nuts in ice cube trays the scientists put in the two morning rooms. “If I’m a bird, what I could do is take some of the provisions and hide it in there so that if I do wake up there in the morning, I can get my own breakfast,” Dr. Clayton said.

Dr. Clayton found that the birds put over three times more pine nuts in the no-breakfast room than in the breakfast room. She argues that the results mean that birds can take action for their future needs, knowing what they’ll need and where they’ll need it."
This and similar experiments in other animals may over the next few years provide more compelling evidence that animals do plan ahead, and thus take away yet another feature that many have thought distinctive to humans.

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