Cognitive tactics of Bengalese finch (Lonchura striata var. domestica) for song discrimination in a go/no-go operant task

Twelve Bengalese finches (Lonchura striata var. domestica) were trained to discriminate between a conspecific and a heterospecific song in a go/no-go operant task. Training the birds to go for the conspecifics song or to go for the heterospecific song required the same number of training sessions. Nine possible cognitive tactics could be used to solve this task, but probe tests revealed that the birds used only four. Six birds memorized only the “no-go” stimulus and responded to the rest of the stimuli (no-go memory), two birds classified songs according to the species category (open-ended categorization), one bird memorized both of the training stimuli but responded by chance to the probe stimuli (rote categorization), and two birds combined open-ended and rote categorization tactics (combined categorization). These tactics were related to the number of sessions needed to reach the species-discrimination criterion. Our results suggest that investigators should consider individual cognitive tactics and the pitfalls of go/no-go discrimination when interpreting the results of operant discrimination tasks.