According to a new study, rats can detect time by touching a button every 3.2 seconds to obtain a reward. The goal of the experiment, aside from allowing the rats to watch a rat-themed game show, was to see if rats’ behavior was just based on recent rewards, or if they could also rely on more complicated representations of their actions.
The tasks in this experiment centered on pressing a lever. The rats were given the option of pushing a lever twice with the maximum reward with an interval of 3.2 seconds or constantly pushing the lever for 3.2 seconds, according to the study published in the journal PNAS. The rats experimented with pushing the lever and watching what came crashing through a reward port in response to their actions across hundreds of attempts. They were rewarded for getting the right time, and if they pushed for the right interval or length of time again, they’d get another.
The researchers were able to learn more about the rats’ accuracy by rewarding them more for attempts that were closest to 3.2 seconds. Surprisingly, all of the rats understood the concept of it — and their attempts came closer and closer to the goal time as time went on. “When we initially got the data, we couldn’t believe what we were seeing. “We even wondered if the rats were playing a joke on us,” lead scientist Tadeusz Wadysaw Kononowicz told New Scientist. “Our findings add a whole new layer of complexity to rats’ mental representations of time.”
This suggested that the rats were evaluating how their degree of reward matched up to their behavior and adjusting their timing accordingly in order to maximize their reward. The ability is similar to an internal stopwatch, allowing the animals to time actions and repeat the duration of activity with accuracy. The authors of the research note that “evaluating the depth of representations reflecting animals’ perception of time and place is a major problem in neuroscience.”
The researchers were able to determine whether the rats were keeping time or simply reacting to rewards, and “the results show that rats track their own timing errors, deepening our understanding of rodent error-monitoring abilities and the richness of their representation of elapsed time,” according to the researchers. So it appears that keeping time with an internal stopwatch may be added to the extensive list of skills that rats possess, alongside driving vehicles, returning favors, and playing hide and seek.