Processing of empty and filled time intervals in pigeons

Abstract

Pigeons were trained initially with 2-and 8-sec empty or filled intervals as sample stimuli. Interval onset and termination was signaled by 1-sec start and stop markers. Following retention and psychophysical testing, both groups were trained with the alternative type of interval, and the tests were repeated. Group empty-first demonstrated a choose-long effect with both empty and filled intervals. Group filled-first demonstrated a weak (and nonsignificant) choose-short effect with filled intervals and a robust choose-long effect with empty intervals. Both groups tended to time the markers and to add that duration to the sample duration only on filled-interval trials. Initial training with empty intervals alters the way pigeons process temporal information on filled-interval trials, whereas initial training with filled intervals has little effect on the processing of temporal information on empty-interval trials.

The role of keypecking during filled intervals on the judgment of time for empty and filled intervals by pigeons

“…also conducted psychophysical tests with different marker durations on empty-interval trials, and they did not find an increase in the percentage of long responding as marker duration d was increased. This finding replicated a result reported previously by Grant and Talarico (2004). Santi et al went on to test an attention-sharing explanation of the emptyfilled timing difference.…”

Unraveling sources of stimulus control in a temporal discrimination task

“…This alternative account is also consistent with the results obtained in studies on the timing of empty intervals, that is, intervals signalled by brief start and stop markers (Grant, 2001;Grant & Talarico, 2004;Santi, Hornyak, & Miki, 2003;Santi, Ross, Coppa, & Coyle, 1999). In these studies, the subjects seem to add the retention interval to the sample stimulus, leading to a "long"-key bias.…”

Subjective shortening with filled and unfilled auditory and visual intervals in humans?

“…In general, responses after unfilled intervals seemed better described by a "choose long" effect than by a "choose short" one. Other apparent differences in memory for filled and unfilled intervals in pigeons were obtained by Grant and Talarico (2004).…”