A rudimentary form of time-dependent awareness in mice.

Abstract

Keeping track of event times and the uncertainty in the resultant representation time intervals is pivotal for adaptive decision-making and action planning. To this end, earlier experiments showed that humans and rodents can generate adaptive biases in decision-making considering their representational timing uncertainty. More recent studies showed that humans and rats can also track whether and how much one has underestimated or overestimated the duration of an event (resulting from timing uncertainty). These studies overlooked a more rudimentary form of time-dependent awareness-that is, knowing whether or not a response is emitted under temporal control. This type of dual-system control is a common feature of responses in tasks requiring animals to wait. We tested this hypothesis in C57BL/6 male mice (N = 16) that were trained to depress a lever for a minimum target duration to receive a reward. No reward was given when mice under-produced the minimum required target interval. During test trials, the rate of nose-pokes into the food hopper during a variable response window following time production was recorded. Mice nose-poked more vigorously (reflecting higher reward expectancy) following temporal productions around the target duration compared with when they underproduced the minimum target interval. This result suggests that mice can monitor whether their responses resulted from temporal control versus its failure. Our findings point to a rudimentary form of time-dependent awareness in mice.