Rat Roadsters Taught Researchers to Relish the Journey

Move over NASCAR! The University of Richmond debuted a new type of racecar. This custom carrier, referred to as an ROV (for “rat-operated vehicles) was designed with rodents in mind, The Conversation reports. 

Kelly Lambert, a professor of behavioral neuroscience, led research that consisted of a series of experiments that placed rats in the driver’s seat. Her observations of how these whiskered chauffeurs behaved behind the wheel may provide key insights into how joy and anticipation benefit our brains.

The Ratmobile
The BBC reports that the researchers originally built a simple vehicle made from a plastic jar, stuck on top of an aluminum plate, with wheels attached. They used a copper wire to close a circuit and make the car move. Rats were given three bars to press – one to make the vehicle move forward, one to make it turn right, and one to make it turn left. To motivate the rats to learn to drive they were given little bits of cereal.

In The Conversation, Lambert clarified that her initial goal in studying the rat racers was to gain insight into how rodents learn new skills. She used an approach called operant conditioning that applies incentives to reinforce behaviors in order to train the rats “step-by-step in their driver’s ed programs,” Lambert wrote. 

It turned out that the rats made relatively good drivers and were fast learners.“Initially, they learned basic movements, such as climbing into the car and pressing a lever. But with practice, these simple actions evolved into more complex behaviors, such as steering the car toward a specific destination,” Lambert added.

Over time the rats’ driving skills improved as did the vehicle they were operating. A robotics professor at the University of Richmond, John McManus, devised a high-tech, specialized car that he called an ROV — rat-operated vehicle. 

Enrichment aids learning
The study’s rats were divided into two environments. Some of them lived in typical rat cages, whereas others enjoyed an enriched space filled with toys and companions. While all the rats eventually learned to drive, Lambert found that those who lived in the enriched environment were faster learners than those in standard cages. 

“This finding supported the idea that complex environments enhance neuroplasticity: the brain’s ability to change across the lifespan in response to environmental demands,” Lambert wrote.

Rats loved driving
The study initially demonstrated that rats are natural racers or at the very least natural learners. Lambert wrote that, “As a neuroscientist who advocates for housing and testing laboratory animals in natural habitats, I’ve found it amusing to see how far we’ve strayed from my lab practices with this project. Rats typically prefer dirt, sticks and rocks over plastic objects. Now, we had them driving cars.” 

The rats, BBC reports, seemed to enjoy not just driving, but also the process of learning a new skill. The rats attending driver’s ed had higher levels of dehydroepiandrosterone, a hormone that counteracts stress, in their droppings. Researchers theorized that this may have been linked to rat’s satisfaction at learning something new. The rats also appeared more at ease while learning to drive.

Lambert designed a control experiment to determine if rats were enjoying the ride or the cereal reward more. According to The Conversation, she gave rats two paths to a Froot Loop Tree. The footpath was shorter and more direct, whereas the driving path took longer. Lambert found that two-thirds of her rat participants turned away from the cereal tree and towards their cars in order to drive there, suggesting that for the rats the journey was as enjoyable as the reward.

Exploring joy and anticipation
Lambert shifted her study’s focus from stress hormones in rat drivers to the link between joy, anticipation, and neural functions, after making a surprising observation. 

“It was the summer of 2020,” Lambert recalled, “A period marked by emotional isolation for almost everyone on the planet, even laboratory rats. When I walked into the lab, I noticed something unusual: The three driving-trained rats eagerly ran to the side of the cage, jumping up like my dog does when asked if he wants to take a walk.”

Lambert observed other signs of joy and anticipation in the rats. For example, they would start revving their engines and pushing the car’s levers even before being placed on the ground.

Lambert designed a series of studies to explore the neural impact of anticipation. She, and fellow researcher Kitty Hartvigsen, debuted the Wait For It research program, exploring the behavioral and cognitive differences between rats that were given rewards right away versus those who had to wait up to 15 minutes for a reward or positive experience. 

Although the study is still ongoing, early results suggest that waiting for a reward makes rats more optimistic. Rodents in the anticipation group also did better on cognitive tasks and problem solving. It seems that good things are worth waiting for and that the wait itself may make people and not just rats happier, less stressed and better at problem solving.