Summarized by Dan Miller, Adam Chazan, and Matt Smith (additions and comments by Frawley)
Piaget believed that infants had no concepts of permanent objects. In assuming this viewpoint, we are faced with three main questions. Do we have object permanence? How do we know this is so? How would babies learn that objects are permanent? The answer that we give to this question is that we really don't know that objects have permanence, but rather this is something we must believe. For example, there is no way of me knowing that my car is sitting out in fromt of my house where I parked it last weekend; however, I believe that it is still there. There are circumstances that I could expect or know about which would lead to me to belive that my car is not there. This is where we find the fault in Piaget's theory.
To Piaget, search tasks were the most important concept to master. Piaget was concerned with how perception could be overcome by knowledge -- cognition could "jump over" perception. This is seen in the experiments where the babies are exposed to covereed objects. At a young age, (6-10 months) babies begin an active search for missing objects. At this age, babies are able to locate the object hidden under the cloth. However, when the object is moved under a different cloth, the baby will still look under the original cloth for the object, despite seeing that it was moved underneath the other. This is referred to as the "a not b error."
Babies move on to the next stage at approximately 12 -15 months. Here babies express a novel combination of prior schemes. In this stage, when the baby sees the object moved to under a different cloth, he/she will identify that the object is under cloth b. However, when the baby does not see the object being moved, he/she will continue to look under the first cloth. Babies move out of this stage at around 18-24 months, where they gain the ability of mental representaions, along with other ideas such as invisible replacement, pretending, and detours. Here the babies can identify the object no matter how it is moved to the other cloth.
Note: the cognition over perception argument comes through here because the babies are claimed to be in a stage where they have to overcome their perceptual beliefs and apply more abstract cognitive beliefs to solve the problem. Note also the assumptions: babies follow developmental stages from more concrete and simpler to more abstract and complex. Is this true?Tests for object permanence that counter the Piagetian view were done by Renee Baillargeon. Her method consisted of a screen that moved at 180 degrees and, in doing so, at times hid or exposed an object to the baby. The test looked at the amount of time that the baby stared at the scene while the screen was moving under the assumption that if a baby stares a while at a scene, it means that the baby is experiencing "wonderment," and so is suprised at the results. When the object is hidden, and the screen lowered fully to "crush" the hidden object, a baby without object recognition thinks that the object has vanished and so is not surprised by the event (does not stare). But the baby with object recognition realizes that the object is still there and expresses surprise at the full lowering of the screen over a hidden object.
Piaget claimed the following:
Sensorimotor 1:
0-9 mos.: no object permamence (out of sight, out of mind)
Evidence: < 9 mos., no search for a covered object, no sense of world outside themselves; > 9 mos., search.
9-12 mos.: objects have a fixed locale; absolute position
Evidence: < 12 mos., search where object first found; > 12 mos., search where last seen
12-18 mos.: objective locations and position changes
Evidence: < 18 mos., no search beyond where last seen; > 18 mos., search to inferred positions
18-24 mos., infer objects from representational laws
Usng her noninvasive, nonmotoric problem-solving method, Baillargeon has found: 3.5 mos., objects persist, compare against existing trajectory in space
4.5 mos., object-centered locations
4.5 mos., use reference objects to infer existence and properties of hidden objects
7.5 mos., object-centered properties (height, texture, compressibility)
9.5 mos., infer existence of object from projected properties only
11..5 mos., surprise if object left in place not inferred
12.5 mos., infer size and properties of hidden objects
That is, with the right testing, children in Piaget's earliest stages can be shown to possess knowledge that is said to occur only at the latest stages. Does this mean that object knowledge is continuous in development? (Or could chcildren have still leartned this information in the 3.5 months between birth and the time of the Baillargeon experiments?) The problem with Piaget, Baillargeon argues, is that he asked young children to perform a motoric problem-solving task with complicated planning and strategies for solution. These performance factors prevented them from demonstrating their existing knowledge of objects, their initially powerful spatial competence.
Summary of Frawley's Presentation on U-shaped Learning
The u-shaped curve is a display of correct learning over time. A u-shaped curve is the display of verb tense learning. Originally, the child learns past tense verbs correctly, then their "correctness" seems to drop off, and finally they regain their correct answers. Why does this happen? At first, when the child is first exposed to verbs, he only learns the basic correct form of the verb. Over time, his view of the word changes as he learns new rules for forming tenses of verbs. Eventually, the child learns the correct forms after using the language for a while by trial and error. This period can be called a rebuilding period. There are two different ideas about how a child learns: either discontinuous or continuous. Discontinuous learning is based on the idea that external data shapes the way in which a child learns. It assumes that an outside input is used to modify the baby's original hypothesis of a certain subject. Continuous learning states that the baby plays with his hypothesis in his head until eventually he gets it right. Therefore, according to this approach, what the baby learns in the outside world doesn't necessarily correspond with what he learns in general.