PRACTICE MODULATES THE EFFECT OF EXPECTING A GAP IN TIMING
In previous studies on time production with gaps, participants were asked to interrupt and then to resume timing during a time interval production. Produced intervals consistently lengthened as the gap occurred later, revealing temporal underestimation related to pregap duration. This effect was explained by referring to two main mechanisms: 1) attention sharing between timing and monitoring for the gap signal, and 2) preparation to interrupt timing while the gap is expected. In the present study, two participants were tested in a 2.5-s time production task with gaps in 20 experimental sessions. Produced intervals lengthened with increasing value of gap location as in previous studies, but this effect was clearly modulated by practice: the slopes of functions relating produced intervals to gap location generally increased during the first 10 experimental sessions, and then stabilized. In contrast, the intercepts of these functions were unaffected by practice. These results suggest that practice specifically influences processes related to gap expectancy, namely, attention sharing and/or preparation to interrupt timing.