ABSTRACT
Development of neural structure and function has been viewed as a continuous and linear process in which an immature nervous system is transformed into its final adult form by the addition here and there of bits and pieces in a progressive way. The appreciation of the competence of early neurobehavioral mechanisms opened a new and fresh approach into the study of developmental processes of brain and behavior. Even in nonmetamorphic vertebrates the developing brain undergoes transformations that consist not only of the addition of newly formed elements, but also of the disappearance of elements that seem to be functional at certain early stages. The transient neural functions include the palmar and plantar reflexes, consisting of a flexion of fingers and toes after tactile stimulation of the inner side of hand and foot, and the Moro response, a rapid extension and abduction of the arms, followed by an adduction and flexion as a response to a brief vibration to the head.
