Decrement and recovery of responses to olfactory stimuli in the human neonate.

Abstract

Changes in neonates'' breathing responses to inert mixtures of anise oil and asafoetida, or amyl acetate and heptanal, were recorded. After decrement of this response to the mixture over trials, recovery of the response was obtained with a component of the mixture (e.g., either amyl acetate or heptanal), depending primarily on how psychologically similar the component was to the mixture. The decrement to the mixture is therefore interpreted as evidence for habituation rather than sensory fatigue, and the response to the components appears to be a novelty effect following habituation to the mixture.