BRIEF EXPOSURE TO A NOVEL STIMULUS DURING IMPRINTING IN CHICKS AND ITS INFLUENCE ON SUBSEQUENT PREFERENCES

In the course of imprinting, chicks were regularly tested by brief exposure to a novel stimulus in successive choice tests. Their approach towards the novel stimulus relative to their approach towards the familiar was used as a measure of preference. The repeated tests with the novel stimulus were started at four different times after the beginning of imprinting: 21, 43, 65, and 87 min. The first test of each group showed the longer that chicks had been imprinted beforehand, the greater the preference for the familiar. However, chicks trained for 21 min before testing were influenced by the first test and continued to show a preference for the more novel stimulus throughout subsequent testing. By contrast, the other three groups showed a stable preference for the familiar stimulus. © 1979 Psychonomic Society, Inc.