Titrating‐delay Matching‐to‐sample in the Pigeon

Abstract

The titrating-delay matching-to-sample (TDMTS) procedure offers researchers an additional behavioral task thought to capture some important features of remembering. In this procedure, the delay between sample offset and comparison onset adjusts as a function of the subject's performance. Specifically, correct matches increase the delay and incorrect matches decrease the delay, and steady-state titrated delays serve as the primary dependent measure. The present series of experiments investigated the effects of several procedural variables on performance in TDMTS procedures in an effort to elucidate better its features to allow for more precision in future use. Experiment 1 reports results from a parametric analysis of fixed-ratio response requirements on the sample key that indicated improved remembering in the form of higher daily titrated delay values as the requirement was increased. Experiment 2 investigated the extent to which the initial delay value in each session affected session-wide delay values. Results indicated that regardless of value of the initial delay, the subjects' performances adjusted the delay values in the direction of the known baseline delay-value levels. Experiment 3 manipulated the step size by which delay values were adjusted and the results indicated that larger step sizes increased both session-to-session variability and within-session range of titrated delay values, although the average values remained approximately the same. These results suggest that the TDMTS task serves as a promising procedure to study what many refer to as memory.

Impulsive Choice Predicts Poor Working Memory in Male Rats

“…Indeed, the terminal retention intervals in our study are substantially longer than those produced by comparable procedures in animals given fewer sessions [41], [46], [47]. Thus, the TDMTP procedure used here might be a good choice for future studies evaluating the effects of working-memory training on subsequent delay discounting in rats.…”

Olfactory stimulus control and the behavioral pharmacology of remembering.

“…A complete review of this literature is beyond the scope of the present review, but it is worth noting that the delay-independent drug effects often found with DMTS procedures may reflect limitations of the procedure rather than an absence of drug effects on forgetting. For example, the nature of the forgetting function and related sensitivity to drug effects may depend on selection of a sufficient range of delay values (Kangas, Vaidya, & Branch, 2010; Sargisson & White, 2003). Additionally, ceiling effects are often observed in DMTS that may limit detection of enhancement of remembering.…”

Functional MRI and functional connectivity of the visual system of awake pigeons

“…Pigeons are used to study mechanisms of learning and memory, i.e. reinforcement [18], matching [19], interval timing [20], sequence acquisition [21] and equivalence learning [22]. Also, pigeons have traditionally served as a model organism to study perception and its neurobiological and anatomical basis in birds, with a similar wealth of literature as for learning and cognition.…”