Sign tracking in domesticated quail with one trial a day: Generality across CS and US parameters

Abstract

When the conditioned stimulus (CS) is located some distance from the unconditioned stimulus (US), pairings of the CS and US can yield either conditioned approach to the CS (sign tracking) or conditioned approach to the US (goal tracking). However, goal tracking is the more common outcome, and, because of that, goal tracking has come to serve as a 'standard' measure of associative learning in several laboratories. In contrast, in previous studies of sexual conditioning with domesticated quail, only sign tracking was observed. In the present study, quail continued to show sign tracking rather than goal tracking whether or not the US was highly localized (Experiment 1), whether food or a sexual US was used (Experiment 2), whether the CS was mobile or immobile (Experiment 3), and whether the CS was 91 or 233 cm from the US compartment (Experiment 4). The present findings encourage caution in the routine use of goal tracking as a measure of learning. The possible mechanisms of goal tracking are discussed in terms of occasion setting and behavior systems theory.