The influence of non-temporal distractor stimuli on interval timing under conditions expected to elicit covert shifts of attention was examined using seconds range stimuli and the duration bisection task. Distractor stimuli appeared in positions peripheral to the timing signal on half of the trials, but participants were instructed to maintain fixation on the timing stimulus while their eye positions were monitored using an eye-tracker. In Experiment 1, participants ignored the distractors, whereas in Experiment 2 participants counted the distractors. In both experiments, trials with distractors were judged as longer than equivalent duration trials without distractors. Presenting a cue that indicated whether or not the subsequent trial would include distractors (Experiment 3) eliminated this lengthening effect. Taken together, these results suggest that when the presence of distractor stimuli during a trial is uncertain, distractor expectation captures attention that would otherwise be allocated to timing, with the result that perceived duration is shorter on trials in which distractors are absent.
Droit-VoletS.DelgadoM. de L.RattatA. C. (2005).
The development of the ability to judge time in children. In
MarrowJ. R. (Ed.),
Focus on child psychology research (pp.
Hauppauge, NY: Nova Science Publishers, Inc.
PenneyT. B. (2003).
Modality differences in interval timing: Attention, clock speed, and memory. In
MeckW. H. (Ed.),
Functional and neural mechanisms of interval timing (pp.
Boca Raton, FL: CRC Press.
PenneyT. B.AllanL. G.MeckW. H.GibbonJ. (1998).
Memory mixing in duration bisection. In
RosenbaumD. A.CollyerC. E. (Eds.),
Timing of behavior: neural, computational, and psychological perspectives (pp.
Cambridge, MA: MIT Press.
TreismanM.FaulknerA.NaishP. L. N.BroganD. (1990).
The internal clock: Evidence for a temporal oscillator underlying time perception with some estimates of its characteristic frequency.