Imprinting: Reversal of a Preference established during the Critical Period

Abstract

Two distinctive features of “imprinting” originally emphasized by Lorenz¹ were that there was a critical period in which the preference for a particular species was established and that the preference established during this period was permanent and could not be changed by subsequent experience. These two features have been reiterated by Hess², who has added a primacy-recency feature, claiming that the first imprinting experience has priority over a subsequent one. These features of imprinting have been questioned by Sluckin and Salzen³, who treated imprinting as a perceptual learning phenomenon in which the sensitive period is experience dependent and the stability of an imprinted preference is dependent on the amount of experience. More recent reviews by Sluckin³ and Bateson³ have supported this view. In particular the perceptual learning view of imprinting has been developed into a neuronal model hypothesis of imprinting by Salzen⁴ and it predicts that object preferences established by the imprinting process should be subject to reversal given sufficient exclusive and enforced experience of new objects after the end of the so-called critical period. The present experiment demonstrates a reversal of this kind.