Scientists teach rats to drive tiny cars. No, really

In a captivating series of experiments, Kelly Lambert, a professor of behavioral neuroscience at the University of Richmond, has been teaching rats to drive tiny cars, revealing surprising insights into their emotional states and cognitive abilities. The rats not only learned to drive but also appeared to enjoy the experience, exhibiting behaviors indicative of excitement and anticipation.

CNN, The Washington Post, and Live Science reported on the experiments, among others.

Lambert and her colleagues designed custom rat-operated vehicles (ROVs) to study how rodents acquire new skills and how anticipation of positive events affects behavior and neural functions. "Although cars made for rats are far from anything they would encounter in the wild, we believed that driving represented an interesting way to study how rodents acquire new skills," Lambert explained.

The experiments began with the rats learning basic movements, such as climbing into the car and pressing a lever. Over time, these simple actions evolved into more complex behaviors, like steering the car toward a specific destination. The first rodent car was crafted from a plastic cereal container, and as the project progressed, the team created upgraded electrical ROVs featuring rat-proof wiring, indestructible tires, and ergonomic driving levers.

The rats displayed enthusiastic behavior when approaching the vehicles. Lambert noted, "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," demonstrating their excitement at the mere idea of being able to drive a vehicle. Some rats even showed intense motivation by jumping into the car and revving the "lever engine" before their vehicle hit the road.

The research showed that rats housed in enriched environments—complete with toys, space, and companions—learned to drive faster than those in standard cages. This finding supports the idea that complex environments enhance neuroplasticity, the brain's ability to change across the lifespan in response to environmental demands. Rats from enriched environments not only acquired driving skills more quickly but also displayed greater signs of anticipatory pleasure.

Lambert hypothesized that anticipation could be as positive an experience as the prize itself, leading to a deeper understanding of how anticipation of positive events affects behavior and neural functions. "I taught rats to drive, but they taught me to enjoy the ride," Lambert stated, suggesting that the rats enjoy both the journey and the rewarding destination.

Further observations revealed that some rats raised their tails in a characteristic gesture identified as "Straub tail." This body posture is indicative of an increase in dopamine release, a neurotransmitter key in the experience of pleasure. The researchers found that natural forms of opiates and dopamine, key players in brain pathways that diminish pain and enhance reward, seemed to be telltale ingredients of the elevated tails in the anticipation training program. This gesture awakened the team's interest, as it suggests that, like in humans, events that anticipate a reward can stimulate significant changes in the brain.

Lambert and her team designed protocols that included brief waits before delivering rewards, observing that rats showed a more optimistic attitude. After about a month of training, the rats were exposed to different tests to determine how waiting for positive experiences affects how they learn and behave. Those trained to wait for rewards performed better on cognitive tasks and were bolder in their problem-solving strategies. Preliminary results suggest that rats required to wait for their rewards show signs of shifting from a pessimistic cognitive style to an optimistic one in tests designed to measure rodent optimism.

In one experiment, instead of only giving rats the option of driving to the Froot Loop treat, they could also make a shorter journey on foot. Surprisingly, two of the three rats chose to take the less efficient path of turning away from the reward and running to the car to drive to their Froot Loop destination. This response suggests that the rats enjoyed both the journey and the rewarding destination.

These findings provide further support for how anticipation can reinforce behavior and influence neural functions. Neuroscience research is increasingly suggesting that joy and positive emotions play a critical role in the health of both human and nonhuman animals. The rats' behavior underscores how positive experiences and enriched environments can shape the brain in significant ways.

Lambert concluded that there's a lesson in these experiments for humans: waiting for positive and pleasurable experiences may be as gratifying as the experience itself. "Rather than pushing buttons for instant rewards, the rats remind us that planning, anticipating, and enjoying the ride may be key to a healthy brain," she said. Observing tail posture in rats adds a new layer to understanding emotional expression, reminding us that emotions are expressed throughout the entire body.

As animals navigate the unpredictability of life, anticipating positive experiences helps drive a persistence to keep searching for life's rewards. In a world of immediate gratification, these rats offer insights into the neural principles guiding everyday behavior. The researchers concluded that this is a lesson we could learn from these laboratory rats.

The driving rats project has opened new and unexpected doors in Lambert's behavioral neuroscience research lab, continuing with new, improved ROVs designed by Randolph-Macon College robotics professor John McManus and his students. This ongoing research provides further support for how anticipation and positive experiences can influence behavior and neural functions, offering valuable insights into the connections between environment, emotion, and cognition.

This article was written in collaboration with generative AI company Alchemiq