The choose-short effect and trace models of timing

The tuned-trace multiple-time-scale (MTS) theory of timing can account both for the puzzling choose-short effect in time-discrimination experiments an d for the complementary choose-long effect But it cannot easily explain why the choose-short effect seems to disappear when the intertrial and recall intervals are signaled by different stimuli. Do differential stimuli actual ly abolish the effect, or merely improve memory? If the latter, there are w ays in which an expanded MTS theory might explain differential-context effe cts in terms of reduced interference. If the former, there are observationa l and experimental ways to determine whether differential context favors pr ospective encoding or some other nontemporal discrimination.