Imprinting and Perceptual Learning

Abstract

Filial responses are first considered by reference to the initial stimulus situations. Findings on variability in responsiveness of chicks are reported and discussed. Facilitated responsiveness subsequent to visual stimulation is reported. The concept of critical period is examined in the light of other workers’ and our own findings; it is concluded that imprinting ends as a result of its own action rather than through the effects of fear. Following responses are further considered by reference to the influences of early experiences and the act of following upon the occurrence and strength of subsequent responses. The degree of attachment to a moving object tends to be proportional to the amount of experience. Individual chicks were allowed to spend several hours following a box in a runway and their ability to discriminate between familiar and unfamiliar moving objects and static environments was studied. Strong evidence for imprintability to environment has been found. Imprinting phenomena are discussed in terms of perceptual learning.

Effects of group rearing on the control exerted by an imprinting stimulus

“…Thus, during the initial imprinting session, already establishedattachment behaviors directed toward siblings may interfere with the emissionof filial behavior. Consistent with this account, both Guiton (1959) and Sluckin and Salzen (1961) observed that isolating group-reared birds for several hours prior to imprinting resulted in an increase in their subsequent following of the imprinting stimulus. Similarly, Hoffman (1968) found that ducklings confronted as a group with an imprinting stimulus appeared to ignore the stimulus.…”

“…One factor may be the choice of an imprinting stimulus. Most of the studies that have failed to demonstrate strong imprinting have used silent-moving mechanical stimuli (Graves & Siegel, 1968;Guiton, 1959;James, 1960;Sluckin & Salzen, 1961), while studies that have succeeded in demonstrating imprinting generally have employed more complex stimuli (Polt & Hess, 1964;Smith & Bird, 1964; the present research; but see Hoffman, 1968).…”

“…Those studies in which young birds are allowed to interact in a group prior to exposure to an imprinting stimulus usually have reported that the bonds between the members of the group preclude or greatly attenuate attachment to the imprinting stimulus (Graves & Siegel, 1968; Guiton, 1959; James, 1960;Polt & Hess, 1964; Reese, Schotte, Bechtold, & Cowley, 1972;Sluckin & Salzen, 1961). Thus, when group-reared birds were confronted as a group with an imprinting stimulus, they either ran from the stimulus or ignored it (Guiton, 1959;Sluckin & Salzen, 1961). Furthermore, when group-reared birds were confronted individually with an imprinting stimulus, they also tended to ignore it.…”

Imprinting: Transfer of the following response after initial attachment

“…There are thus "inhibitory effects of socialization on the following response to unfamiliar objects." A similar conclusion was presented by Sluckin & Salzen (1961) who stated that with increased imprinting "the bird becomes less likely to respond to stimuli other than the experienced one or ones." In accordance with the above conclusions, it has been shown that the "critical period" during which stimulus exposure can elicit following behavior can be significantly lenghtened if the bird is deprived of visual and/or social experience after hatching (Moltz & Stettner, 1961;Sluckin, 1962).…”

Distress calling induced by reductions in group size in ducklings reared with conspecifics or imprinting stimuli

“…This, in turn, raises a final and related issue. Investigators employing an imprinting stimulus commonly assume that this stimulus is serving as a mother surrogate (e.g., Hess, 1973;Hinde, 1974;Hoffman & Ratner, 1973;Sluckin, 1965;Sluckin & Salzen, 1961). The present research, however, emphasizes the need to critically examine the relationship between imprinting stimuli and natural social companions in a young bird's environment-mother, siblings, potential mate, or whatever.…”