Date of Award:


Document Type:


Degree Name:

Master of Science (MS)




Amy L Odum


There are differences within the timing literature regarding the effects of distracter stimulus presentation within timing tasks. Whereas some researchers have found underestimation (changes in the degree of temporal stimulus control), others have found generalized disruption of timing responses. The purpose of this thesis was to determine the importance of food availability on responses within a time estimation task, using pigeons as subjects. Specifically, it was hypothesized that presenting food access following timing responses after a distracter task would produce underestimation of the target interval, relative to control conditions. Using a 2-parameter function fit to "proportion long" data from the interval bisection task, data revealed a generalized disruption effect of the distracter on timing behavior. Further analysis revealed that presentation of the food following timing responses after the distracter task reduced stimulus control within the timing task, revealing underestimation of the target interval. These findings suggest that the causes of the differences within the timing literature may be based upon differences in procedure.