Two experiments were conducted to specify the effects of the preexposure of a taste or an odor stimulus upon the compound (taste-odor) aversion conditioning, in which the preexposed stimulus forms a part (T1 ·O1) or in which it forms no part (T2 ·O2). In two-bottle testings, the comparisons were made between following pairs : T1 vs, T2, T1 · 1 vs, T2 ·O2 and O1 vs. O2. In Experiment 1, a preexposure of the taste component (T1) tended to restrain aversion formation to the stimulus (T1), whereas it did not restrain that to the compound one (T1 · O1) as well as that to the odor component (O1) (Figs 1&2). On the other hand, in Experiment 2, a preexposure of the odor component (O1) tended to restrain aversion formation not only to the stimulus (O1) but also restrains that to the compound CS (T1 ·O1), and also to the taste component (T1) (Figs. 3&4).
Contact behaviors in mother-infant relationships was investigated in this study. Eight pairs of infant (four males and four females) and mother were observed for the first three months of infant age. Behaviors monitored included contact, proximity, infant's locomotion, clinging, nipple contact, embrace, and grooming. Contact, proximity, and most of infant's behaviors decreased with the passage of time (Table 1). But other behaviors, particularly mother's locomotion and grooming did not the tendency (Table 1). Contact, clinging, and embrace decreased rapidly between 1 week and 1 month of infant life (Figs.1, 2b, and 3b), but nipple contact and grooming did not show this tendency (Figs. 2b and 3b). It suggests that mother and infant relationship in early stage of development is a process to change very gradually.