How newborns perceive complexity: the nose capabilities

All organisms face an environment inherently complex. From this complexity, they must extract information to survive. To that goal, they can either respond to constant stimuli, or rapidly acquire new information. Clearly, this challenge already exists at birth. Regarding olfaction, newborns may spontaneously respond to key-odorants, as the mammary pheromone (MP) in newborn rabbits, a molecule carried in the complex odor of milk. In addition, rabbit pups learn novel odorants from their perinatal environment. Strikingly, the MP by itself promotes the rapid acquisition of other, simple or complex, odors and constitutes an interesting tool to investigate how the neonatal brain deals with olfactory complexity. Here, we will illustrate the capacity of neonatal olfaction to function in the elemental way, through the extraction of the component's odors into a mixture, and in the configural way, through the perception of a new odor distinct from the constituents' ones. Similarities exist with human adults. Thus, from early in life, mammals may grasp their chemosensory surroundings through diverse perceptual strategies, contributing to their optimal adaptation