Editing Object permanence (section)

==Stages==
[[File:US Navy 100406-N-7478G-346 Operations Specialist 2nd Class Reginald Harlmon and Electronics Technician 3rd Class Maura Schulze play peek-a-boo with a child in the Children's Ward at Hospital Likas.jpg|thumb|alt=US Navy 100406-N-7478G-346 Operations Specialist 2nd Class Reginald Harlmon and Electronics Technician 3rd Class Maura Schulze play peek-a-boo with a child in the Children's Ward at Hospital Likas|[[Peekaboo|Peek-a-boo]] is a prime example of an object permanence test.<ref name=Kitajima>{{cite journal |last1=Kitajima |first1=Yoshio |last2=Kumoi |first2=Miyoshi |last3=Koike |first3=Toshihide |title=Developmental changes of anticipatory heart rate responses in human infants |journal=Japanese Journal of Physiological Psychology and Psychophysiology |year=1998 |volume=16 |issue=2 |pages=93–100 |doi=10.5674/jjppp1983.16.93 |id={{ProQuest|619539004}} |doi-access=free }}</ref>]]

In Piaget's formulation, there are six stages of object permanence.<ref>{{Cite book|title=The essential Piaget|last=Piaget|first=Jean|date=1977|publisher=Routledge and K. Paul|editor1=Gruber, Howard E.|editor2=Vonèche, J. Jacques.|isbn=978-0710087782|location=London|oclc=3813049}}</ref> These are:

# 0–1 months: '''Reflex schema stage''' – Babies learn how the body can move and work. Vision is blurred and attention spans remain short through infancy. They are not particularly aware of objects to know they have disappeared from sight. However, babies as young as seven minutes old prefer to look at faces. The three primary achievements of this stage are sucking, visual tracking, and hand closure.<ref name=Anderson>{{cite journal|last=Anderson|first=John E.|title=Review of The construction of reality in the child|journal=Psychological Bulletin|year=1955|volume=52|issue=6|pages=526–8|doi=10.1037/h0039645}}</ref> 
# 1–4 months: '''Primary circular reactions''' – Babies notice objects and start following their movements. They continue to look where an object was, but for only a few moments. They 'discover' their eyes, arms, hands and feet in the course of acting on objects. This stage is marked by responses to familiar images and sounds (including parent's face) and anticipatory responses to familiar events (such as opening the mouth for a spoon). The infant's actions become less reflexive and intentionality emerges.<ref name=Anderson /> 
# 4–8 months: '''Secondary circular reactions''' – Babies will reach for an object that is partially hidden, indicating knowledge that the whole object is still there. If an object is completely hidden, however, the baby makes no attempt to retrieve it. The infant learns to coordinate vision and comprehension. Actions are intentional, but the child tends to repeat similar actions on the same object. Novel behaviors are not yet imitated.<ref name=Anderson /> 
# 8–12 months: '''Coordination of secondary circular reactions''' – This is deemed the most important for the cognitive development of the child. At this stage the child understands causality and is goal-directed. The very earliest understanding of object permanence emerges, as the child is now able to retrieve an object when its concealment is observed. This stage is associated with the classic [[A-not-B error]]. After successfully retrieving a hidden object at one location (A), the child fails to retrieve it at a second location (B).<ref name=Anderson /> 
# 12–18 months: '''Tertiary circular reaction''' – The child gains means-end knowledge and is able to solve new problems. The child is now able to retrieve an object when it is hidden several times within their view, but cannot locate it when it is outside their perceptual field.<ref name=Anderson />
# 18–24 months: '''Invention of new means through mental combination''' – The child fully understands object permanence. They will not fall for A-not-B errors. Also, a baby is able to understand the concept of items that are hidden in containers. If a toy is hidden in a matchbox then the matchbox put under a pillow and then, without the child seeing, the toy is slipped out of the matchbox and the matchbox then given to the child, the child will look under the pillow upon discovery that it is not in the matchbox. The child is able to develop a mental image, hold it in mind, and manipulate it to solve problems, including object permanence problems that are not based solely on perception. The child can now reason about where the object may be when invisible displacement occurs.<ref name=Anderson />