Pigeons were monocularly trained on single stimulus training (S^D : 135° tilted line), interdimensional discrimination (S^D : 135°, S^Δ : blank key), intradimensional discrimination (S^D : 135° S^Δ : vertical line) or mirror image discrimination (S^D : 135°, S^Δ : 45°). Following these training, they were subjected to a stimulus control test with 135° line and 45° line. Subjects in the discrimination groups indicated the mirror image reversal effect, that is, they emitted more responses to the 45° line than to the 135° line in the test with the untrained eye. Whereas, pigeons trained on the single stimulus training responded equally both to the 135° and to the 45°. Stimulus control tests with radius stimuli clarified that subjects which showed the reversal effect discriminated the tilted line on the basis of the eye being used.

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Many studies have been reported on the development of mother-infant relations in nonhuman primates which indicate the importance of early mother-infant relations on the development of the infant. The present study was designed to clarify the development of filial cling and maternal embrace and grooming in the first six months of the infant's life. In the past, we have mainly studied relations between the infant's age of maternal isolation and the patterns of stereotyped behavior induced by the isolation. But this should be based on the study of the development of the mother-infant relations under the normative condition. This is the major reason why the present study was conducted.
The subjects used in the present investigation were three multiparous adult females and their male infants. The adult females were trapped in a freeranging group of Japanese Monkeys at Katsuyama, Okayama Prefecture and were raised at Osaka University Laboratory where they were fertilized (Table 1). Each of the pregnant females was housed in a 60×93×125 cm cage. The observation started at their parturition. All infants were males. Mother-infant interaction was observed for 15 minutes, once or twice a week.
Results were as follows.
1) The infant's locomotion tended to increase and filial cling was inclined to decrease in the first three months of the infant's life (Fig. 1 and Fig. 2).
2) Maternal embrace tended to decrease as same as filial cling did in the first three months (Fig. 3). Maternal grooming, however, did not show this tendency (Fig. 4).
3) The infant's locomotion and filial cling was affected by maternal embrace in the first three months of the infant's life, and by both maternal embrace and grooming after that time.
4) This suggests that the behavioral development of the infant is affected by maternal behavior even in the early months of the infant's life.

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The Ss were 10 male albino rats. After being trained to eat grains of rice from a food cup on the grid floor, the Ss which stepped onto the grid floor received electric shocks, and were tested alone or with a demonstrator which approached and ate the grains of rice. These results, unlike other studies, indicated that pairing with only one demonstrator could induce eating behavior in the Ss.

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[in Japanese]

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