As the researchers suspected, rats raised in an enriched environment "demonstrated more robust learning in driving performance", and their interest in the auto persisted even in the absence of food rewards, suggesting that the "enriched animals may have developed a more engaged reward system throughout training". Check out this footage, courtesy of the University of Richmond.
Lambert has apparently done previous work that found that rats experience a reduction in stress after they master hard tasks, like digging up buried food, suggesting they may experience the same kind of satisfaction people feel after perfecting a new skill. The research findings have been published in the journal Behavioral Brain Research.
Led by senior author Kelly Lambert (University of Richmond), the team took a robot auto kit, added a clear plastic food container as the driver's compartment, and fixed an aluminum plate under that.
When it came time to drive, the rats who played with ladders, balls and toys were more adept at operating and steering the ROV, thanks to the neuroplasticity (their brains' ability to change over time) triggered by their environment. The three bars, upon being pressed individually, could also be used for turning the vehicle left, right, or staying in the center lane.
What gave the rats incentive to actually drive in the right direction?
Scientist knew the rats were more chill and less anxious when they got to drive the cars by testing their excrement for stress hormones.
All in all, the team reports that rats kept in more natural ('enriched') environments performed better than their lab-kept counterparts. A chemical analysis of the animals' poop after four months of training sessions showed lower levels of the stress hormone corticosterone and higher levels of the stress-busting hormone dehydroepiandrosterone (DHEA).
All of the rats in the trial had higher levels of dehydroepiandrosterone, indicating a more relaxed state.
According to the study, the team taught 17 rats how to drive the vehicle, and those who succeeded in reaching the end destination were given Froot Loops as a treat.
In the driving rats, the researchers found that the ratio of DHEA to CS increased, which the researchers said, "suggest [s] that driving training, regardless of housing group [enriched or lab cage], enhanced markers of emotional resilience".
"There's no cure for schizophrenia or depression", Lambert said to AFP. I do believe that rats are smarter than most people perceive them to be and that most animals are smarter in unique ways than we think'.