A Test of Weber's Law with Dogs

Abstract

This study investigated Weber’s Law through a temporal bisection procedure using domestic dogs as subjects, a previously untested species in temporal bisections. Six dogs were trained to response to the blue lever when the short signal duration was presented, and response to the red lever when the long signal duration was presented. The four conditions were 0.5 – 2.0 s, 1.0 – 4.0 s, 2.0 – 8.0 s and 4.0 – 16.0 s. The intermediate durations presented were logarithmic intervals of the two original signal durations. On each trial there were 7 possible durations for the green light, the two trained durations and the 5 intermediate logarithmic durations between them. Reinforcement was provided for correct responses to trained durations through out training and testing, no reinforcement was given for intermediate durations. This study demonstrated the PSE was close to the geometric mean and a failure of Weber’s Law. Weber fractions were not constant and instead produced a U-shaped function. Starting large for the shortest condition, (0.5 – 2.0 s), getting smaller for the middle two conditions (1.0 – 4.0 s & 2.0 – 8.0 s) and increased again for the longest condition (4.0 – 16.0 s). Results demonstrated that subjects found discriminating between durations within the 0.5 – 2.0 s condition the hardest. These results replicate the findings of Church and Deluty (1977) where the PSE was also close to the geometric mean, as well as Bizo et al. (2006) and Zeiler (1991) who were both able to demonstrate a failure of Weber’s Law.