精神分析理论把18个月以前的婴儿时期称为“口唇期”。在这期间,婴儿常常衔着母亲的乳头,以此刺激口腔粘膜而获得快感,如果授乳期间经常不能及时满足婴儿的欲求或授乳期太短,婴儿则会产生不满情绪,称“口腔不满”。精神分析学派的代表人物之一埃里克森认为,这个时期的母子关系,基于婴儿生理性需要的满足与否,可产生婴儿的基本信赖或基本不信赖的心理倾向。此时婴儿的无助感最为强烈,如果母亲 Psychoanalytic theory refers to the infancy of 18 months as the “lip period.” During this period, infants often have their mother’s nipples to stimulate oral mucosa for pleasure. If the baby’s desire or lactation period is often not satisfied during lactation, infants will have dissatisfaction, saying that “the oral dissatisfaction ”. Erickson, one of the representatives of the psychoanalytic school, believes that the mother-child relationship in this period, based on whether or not the baby’s physiological needs are met, can produce the baby’s basic trust or the basic untrust mentality. At this point the most helpless feeling of the baby, if the mother