Post-doctoral researcher Kathleen Quach has spent a lot of time in her Salk Institute lab watching a worm called P. pacificus, an omnivorous creature that’s only one millimeter long. She has found that with a brain made of only about 300 neurons, these tiny creatures can view a situation — and make a decision.
“Worms can do cost-benefit analyses. They can weigh costs and benefits of pursuing an action and what they get in return. And they can do this in very complex ways,” Quach said. “It’s not a very human thing. It’s not a very vertebrate thing. It’s something they can do as well. “
Quach is first author to the paper of her research about worms that appeared in the March edition of Current Biology. It’s a study that upends the assumption that very simple creatures act only on instinct.
The decisions made by P. pacificus involve its behavior toward a competing species of worm, which will be called Worm2. Neurobiologist Sreekanth Chalasani is the senior author of the research paper and a faculty member at Salk.
He said the worm they studied was put in a place where it could eat either bacteria or the larva of Worm2. It was also faced by adult Worm2 competitors that were hard to eat and that P. pacificus really wanted to frighten away.
Chalasani said their worm had a lot of questions to ponder.
“Is the juvenile going to compete with me for the same bacteria? Is the adult going to compete with me or not? Is that adult going to have a lot of babies and compete with me and my progeny? And then, based on all of this calculation, decide a course of action. And that complexity was very surprising to us,” Chalasani said.
The research isn’t just about worms. Quach said mapping the brain signals of simple creatures helps us understand how the human brain works.
And maybe it could help us understand the workings and the uses of artificial intelligence. Chalasani said driverless cars, for instance, need to make decisions about whether to speed up or shift lanes, based on its environment.
“You may not need a lot of complex calculations. You may be able to do it, using a biological system. And the biological system can teach us something about how we can re-engineer artificial networks to make complex decisions.”
So a driverless car may only need the brain of a worm?
“Maybe,” Chalasani said. “I’m being cautious here because the worm is not trying to drive a car!”
If you think studies of worms are not in the scientific big leagues, you should know that worms from the Salk study have been the subjects from previous studies that have won three Nobel Prizes.
