The discrete elicited lateral tongue movement of the human newborn first described under this project continues to be used in psychophysical studies of oral sensation. The transverse tongue reflex described previously can be elicited by separate 5 microliter drops of fluid. The reflex adapts to repeated fluid elicitations. In earlier studies, the response returned when glucose in suprathreshold concentration was added to the stimulus fluid after adaptation to the water. This experimental sequence thus indicates taste discrimination. Current studies address the question of sensitivity to the salty taste and its relation to sensitivity to sweets. BIBLIOGRAPHIC REFERENCES: Thach, B.T. and Weiffenbach, J.M.: Quantitative Assessment of Oral Tactile Sensitivity in Preterm and Term Neonates and Comparison with Adults. Dev. Med. Child Neurol., 18: 204-212, 1976. Weiffenbach, J.M.: Sensory Mechanisms of the Newborn's Tongue. In Weiffenbach, J.M. (Ed.): Taste and Development: The Genesis of Sweet Preference. Washington, D.C., Superintendent of Documents, U.S. Government Printing Office, 1977, p. 205-213.