NATURAL CONDITIONED SALIVARY REFLEX OF 

 MAN ALONE AS WELL AS IN A GROUP 



Takashi Hayashi and Masao Ararei 



Department of Physiology, School of Medicine, 

 Keio University, Tokyo, Japan 



INTRODUCTION 



Kerr (1961) believes, " the commonly held belief that salivation is pro- 

 voked by stimuli to which individuals have become conditioned — for 

 example, the thought or sight of food — does not appear to be supported by 

 any objective studies reported in the literature ". He repeated attempts 

 to elicit any existing conditioned salivary reflexes by presentation of the 

 idea of food, and the sight of lemons and candy was unsuccessful. Thus 

 he was inclined to deny a natural conditioned reflex in man. On the other 

 hand, Hayashi and Suhara (1962) have shown that the artificial conditioned 

 salivary reflex can be established. The method was to measure salivary 

 secretion through a suction cup which was attached to the orifice of the 

 parotid gland of the subject (Lashley, 1916), 



When we do experiments with a suction cup, a parotid gland secretes 

 at fairly steady rates which are characteristic for the individual. This 

 saliva is called ^'resting saliva", and the established conditioned saliva, of 

 course, exceeds the resting value. 



First, a trial was made to evaluate the natural conditioned saliva by 

 the suction cup method in Japanese adults. The persons who were used 

 in the first experiment were between 18-27 and 9-10 years old. The 

 adults were all students of higher schools or universities in Tokyo and the 

 children were boys and girls at primary school. 



DRAWINGS ELICITED NO NATURAL CONDITIONED 

 REFLEX EITHER IN THE ADULT OR CHILD 



Pictures of biscuits, apples and oranges were placed before the subjects 

 while the resting saliva was measured. The saliva did not increase nor 

 decrease. In other words, pictures elicited no natural conditioned reflex 

 within these age-groups. 



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