Time is a subjective experience

Time, like space, is one of the fundamental dimensions of all our experiences. However, organisms do not work like clocks, and our judgment about the passage of time is variable, depending on circumstances. Soares et al. systematically investigated midbrain dopaminergic neurons during timing behavior in mice (see the Perspective by Simen and Matell). When measuring and manipulating mouse activity, the authors observed that dopaminergic neurons controlled temporal judgments on a time scale of seconds.

Science, this issue p. 1273; see also p. 1231