PERSISTENCE OF ACQUIRED BEHAVIORAL CONTROL IN THE CONTEXT OF IMPRINTING¹

Abstract

Newly hatched Khaki Campbell ducklings (Anas platyrhynchos domesticus) were exposed to a moving object that immediately suppressed distress vocalizations occurring in a novel environment. The static visual and auditory features of this object acquired the ability to suppress distress vocalizations after eight 20-min sessions of exposure to the object in motion. The acquired suppressive properties of these features were found to persist throughout thirty 20-min sessions given over 10 days. During these sessions, the ducklings were continually exposed to the static features in the absence of visual movement. In a second experiment, the ability of these features to serve as reinforcement for a pecking response was shown to persist for up to 56 hr. In one duckling, presentations of the static visual features did not maintain pecking behavior. However, it was shown that pecking responses could be re-instated in this duckling by introducing novel stimuli to the environment.

Behavioral control by stimulus components of an imprinting object

“…Among these similarities are the facts that both types of features are initially neutral in their effects upon ongoing distress vocalization (Eiserer & Hoffman, 1974;Hoffman et al, 1972), both types acquire suppressive properties only when they are paired with visual movement (Eiserer & Hoffman, 1974;Hoffman et al, 1972), and, after such acquisition, both types subsequently retain those suppressive properties throughout prolonged periods in which they are no Ionger accompanied by visual movement (Eiserer, Hoffman, & Klein, 1975). The present experiment adds still another Results Figure 2 shows the mean number of seconds of distress vocalization emitted during, and in the 10 sec immediately following, presentations of the moving object and its visual and auditory features, relative to parallel baseline periods.…”

“…Previous work (Eiserer & Hoffman, 1973) has suggested that the same mechanisms underlie priming of both responses, since certain variables (e.g., prime duration and priming with the visual features) affect both behaviors in comparable ways. Measurement of the pecking response, however, offered an advantage over measurement of distress calls in that peking can be maintained over a large number of days (e.g., see Hoffman & Kozma, 1967), whereas ducklings frequently cease emitting baseline distress vocalization once they have habituated to the experimental apparatus-a process that may take but a few hours of exposure to the apparatus (Eiserer et al , 1975). Thus more trials were potentially possible with polepecking than with distress vocalization, and more trials would permit more sensitive assessment of any priming effects that might occur.…”

“…Although the static visual features and the auditory features of a laboratory imprinting object may not innately elicit filial behavior, these features can gradually acquire strong suppressive properties if the ducklings receive prolonged exposure to the object in motion (Eiserer & Hoffman, 1974;Eiserer, Hoffman, & Klein, 1975;Hoffman, Eiserer, & Singer, 1972). Thus, in ducklings that periodically see the imprinting object in motion, the static visual features and the auditory features gradually acquire the ability to suppress distress calls by themselves (i.e., without the accompaniment of visual motion).…”

Acquisition of behavioral control by static visual features of an imprinting object: Species generality

“…It has been documented with several different types of imprinting objects (Eiserer, 1980;Hoffman et al, 1972); it applies to the initially neutral auditory as well as static visual features of an imprinting object (Eiserer & Hoffman, 1974;Hoffman et al, 1972); it can be assessed through a variety of filial behaviors, including suppression of distress calls (Hoffman et al, 1972), approach responses (Eiserer, 1980), operant responses (Eiserer et al, 1975), and-if Klopfer's (1965) findings are accepted as relevant-choice behavior; it can be seen in imprinting that occurs after as well as during the sensitive period (Gaioni et al, 1978); and, as indicated by the present work, it occurs in a wide variety of precocial birds. Given the empirical inconsistencies that often plague the imprinting literature and given the realization that seemingly important behavioral effects sometimes tum out to be highly dependent upon peculiar experimental parameters (Eiserer, 1978a), the contextual independence of the acquisition phenomenon is reassuring to those who would ponder its underlying processes.…”

“…As noted elsewhere (Eiserer, 1978b(Eiserer, , 1980, the acquisition of behavioral control by initially neutral features of an imprinting object seems to represent the very essence of infantile attachments to specific surrogate objects. Moreover, the acquisition phenomenon is of great theoretical interest as well, particularly in connection with classical conditioning vs. perceptual learning theories of imprinting (Eiserer, 1978b(Eiserer, , 1980 however, apparently the only precocial bird in which the effect has been specifically studied is the duck (Eiserer, 1977(Eiserer, , 1980Eiserer & Hoffman, 1973, 1974Eiserer, Hoffman, & Klein, 1975;Gaioni, Hoffman, DePaulo, & Stratton, 1978;Hoffman et al, 1972). Klopfer (1965) reported a similar effect in chicks; subjects exposed to a moving object subsequently preferred that object even when it was stationary.…”