Developmental change of sucking response to taste in infants.
Seventy-one full-term normal newborns were studied at the age of 5-7 days. A 0.1% tartrate or a 0.25% saline solution was given to each infant after 1-2 min of breast or bottle feeding and then the same solutions were once more given to the same subjects. Sucking rhythm was recorded and the infants' behavioral reactions were observed by examiners and analyzed on videotape. There were individual differences in the newborn's response to taste. Infants showed a similar response tendency to tartaric acid and saline solution, when given on two different occasions, respectively. But generally they reacted more strongly to saline than to tartrate. Next, sucking response to taste was studied in 20 infants once a month from birth until 5 months old. Five of them had severe brain damage and the other 15 infants were normal. The methods used were the same as those described in part 1. All 5 infants with severe brain damage initially showed a strong reaction and then a decrease of reaction. Fourteen normal infants were followed until 5 months of age: 12 of them showed a decrease of reaction between 1 and 5 months. Most of them showed decrement between 3 and 5 months. From our results, sucking response to taste in the newborns is assumed to be a subcortical reflex and not a cortically recognizable one. It might be called a primitive sucking response, which gradually decreases like any other primitive reflex does.
Maekawa
K
K
Department of Pediatrics, Jikei University School of Medicine, Tokyo, Japan.
Sano
M
M
Nakae
Y
Y
D002657:Child Development; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology* / Q000523:psychology; D008297:Male; D011930:Reaction Time; D012965:Sodium Chloride; D013391:Sucking Behavior; D011795:Surveys and Questionnaires; D013644:Tartrates; D013649:Taste; D013694:Temperament
D013644:Tartrates; D012965:Sodium Chloride; C029768:tartaric acid