Increased Variability in Pigeons Exposed to a Peak Procedure with Gaps and Distractors with Intervals of Different Duration

Several studies have assessed the insertion of a gap or a distractor in a peak procedure. A rightward shift in the peak time has been consistently reported in both cases. The Time-Sharing Model (TSM) explains this effect as a disruption in the timing mechanism caused by the distribution of attentional resources when these events are presented concurrently with the timing task. According to the model, subjective time decays during the presence of a distractor or gap, resulting in the observed rightward shift, regardless of the distractor’s proportion within the interval. Recent research suggests that changes in performance during timing tasks may be influenced by motivational factors and alternative behaviors rather than disruptions in the timing mechanism. Motivational hypotheses propose a dissociation between certain observed behaviors and the underlying timing mechanisms, indicating that the rightward shift in peak time may be attributed to increased latency in initiating timing behaviors. Consequently, stimuli that reduce likelihood of emitting timing behaviors may have distinct effects on intervals of different durations. To assess these effects, we manipulated the duration and proportion of gaps and distractors within the same procedure, aiming to determine if alternative behaviors evoked by the stimuli or the decay memory proposed by the TSM can account for the observed effects. Our data do not fully support the assumptions of the TSM, and the results suggests the importance of an integrative timing model that considers different components of the performance of subjects in timing tasks.