Conditioned suppression of distress calls in imprinted ducklings.

Abstract

Newly hatched ducklings were exposed to imprinting procedures and their subsequent filial reactions were studied using a classical conditioning paradigm. The first experiment revealed that a previously neutral stimulus can become a conditioned suppressor of distress calling as a consequence of pairing it with the imprinted stimulus. If the presentation of the imprinted stimulus was, however, omitted or delayed, or if it preceded rather than followed the presentation of the neutral stimulus, the effect was not obtained. The second experiment utilized a differential conditioning procedure to investigate the capacity of imprinted ducklings to come under discriminative control. Two differently colored lights were used as stimuli; one was consistently followed by presentation of the imprinted stimulus, the other was never followed by its presentation. Only the former stimulus came to suppress distress calling. The importance of the apparent interaction between classical conditioning and imprinting is noted.

A reinforcement model of imprinting: Implications for socialization in monkeys and men.

“…It is noteworthy that similar operant responses have been taught to infant monkeys utilizing exposure to the mother surrogate as the reinforcing event (Harlow, 1958). In addition, Hoffman, Barrett, Ratner, and Singer (1972) have shown that the ability of an imprinting stimulus to suppress a duckling's distress calls can be classically conditioned to initially neutral environmental stimuli.…”

Rates of distress vocalizations in naive domestic chicks as an index of approach tendency to an imprinting stimulus

“…Zajonc familiar stimulus, reduces distress calling (Zajonc,Markus,& Wilson 2) even when the prior exposure to the stimulus occurred prenatally (Rajecki, 1972). In a series of studies, Hoffman (Hoffman, Barrett, Ratner,& Singer, 1972;Hoffman, Eiserer, & Singer, 1972;Hoffman, Ratner,& Eiserer, 1972) employed the distress calling of ducklings to investigate, among other things, the changes in behavioral control exerted by different stimuli and differing amounts of experience with those stimuli. In all these studies, vocalization behaviors are taken as an index of attachment to the familiar.…”