Demonstration of the scalar property of timing with possums (Trichosurus vulpecula).

Abstract

Many diverse species have demonstrated interval timing, the ability to respond appropriately to time in the range of seconds to minutes, suggesting that an ability to time is adaptive. The peak procedure is a common method of studying interval time perception. In the peak procedure, animals experience a mix of fixed-interval (FI) and extinction (EXT) trials. On EXT trials, responding typically increases to a peak at the time the FI schedule would normally deliver reinforcers before decreasing. Responding on different FI schedules within the peak procedure has been found to conform to Weber's law, whereby response variability is proportional to the length of the fixed interval. We conducted possibly the first investigation of the timing abilities of a marsupial common to Australia and New Zealand, the brushtail possum (Trichosurus vulpecula), using FI 15-, 30-, and 60-s schedules of reinforcement in the peak procedure. Response rates on EXT trials peaked at the time of usual reinforcer delivery, decreasing at longer time intervals, and were well fit by 3-parameter Gaussian curves, demonstrating the ability of possums to respond to time-based stimuli. Coefficients of variation suggested that the ability of possums to time was less accurate than that of mammals, but similar to that of birds, invertebrates, and reptiles. Coefficients of variation did not differ consistently over increasing FI intervals, showing that timing responses of possums likely conforms to the scalar property of timing also shown by other species. (PsycINFO Database Record

The face of animal cognition

“…An increasing number of animals have been found to have some kind of number skill, whether numerosity, counting, sequencing or something similar (Bar-Shai et al 2011;Garland & Low 2014;Petrazzini et al 2015Petrazzini et al , 2017Tello Ramos et al 2015), and while most investigation into timing ability is still undertaken in pigeons and rats (e.g. Smith et al 2017), possums Trichosurus vulpecula and long-tailed bats, Glossophaga soricina, are now included in the list of species that are able to time intervals (Toelch & Winter 2013;Sargisson et al 2016).…”

Translating Behavior Analysis: a Spectrum Rather than a Road Map

“…Russell and Burke (2016) conducted five experiments that demonstrated conditional samedifferent learning in a short-beaked echidna. Sargisson, Lockhart, McEwan, and Bizo (2016) reported that the scalar property-a psychophysical feature of respondingoccurred in brushtail possums' lever pressing for food in a peak-interval procedure. Each of these reports is an example of T0 behavior analysis because the studies used experimentally controlled settings, abstract or unfamiliar stimuli, and convenient reinforcers.…”

Weber’s Law and the Scalar Property of Timing: A Test of Canine Timing

“…Time perception is a fundamental cognitive ability and has been demonstrated in a variety of species, including rats (e.g., [4,5]), pigeons (e.g., [6,7,8]), fish (e.g., [9,10]), mice, (e.g., [11]) and possums [12]. The ability to time events and adapt to temporal change in one’s environment has considerable value to the survivability of an individual [13,14], and it has been argued that timing is critical to multiple aspects of sensation, perception, and behavior, and that different neurological structures are implicated in different aspects of timing [15].…”

“…They demonstrated that dogs were able to perform the task and produce timing performance when tested with durations intermediate the training stimuli. The dogs performed similarly to rats [5], monkeys [33], and other animals [12,26].…”