Lecture 4: Cognitive development Flashcards
object knowledge
Understanding that objects
Have substance
Maintain their identity when they change location - changing location doesn’t change the object itself
Continue to exist (ordinarily) when out of sight – otherwise, “out of sight is out of mind”
A not B task
In Piaget’s classic A-not-B task, the infant watches an object being hidden in one location (A) and successfully finds it
This process is repeated several times for location A
The infant then watches the object being hidden in a new location (B)
Crucial test: where does the infant search for the object:
Infants who show the A-not-B error still search in location A rather than location B
Factors affecting whether children make the A-not-B error
Highly replicable (meta-analysis from Wellman et al., 1986) – the basic result is not in doubt
A great deal of research has examined factors that make the A-not-B error more or less likely to occur, e.g.,
age of child - usually pass after 12 months
length of delay - longer delay, more likely to make the error
number of hiding locations - more likely to make AnotB error if there are fewer hiding locations
number of times object hidden in location-A
New tests for object permanence
Infants appear more competent when tested via visual attention measures (e.g., looking times) than when given tests that require them to take action (Baillargeon et al., 1989)
In contrast to Piaget’s description of the development of object permanence, a great deal of evidence now indicates that young infants are in fact able to mentally represent and think about the existence of invisible objects and events
The majority of the evidence is based on research using the violation-of-expectancy procedure, in which infants are shown an event that should evoke surprise or interest if it violates something that the infant knows or assumes to be true
violation of expectancy
Baillargeon (1987) and her colleagues have used this technique to establish that infants as young as 3½ months of age look longer at an “impossible” event than at a possible event
The infants mentally represented the box (understood object permanence) even when it was occluded and were surprised when the screen seemed to pass through the bo
Why do children show object permanence with a VoE procedure, but not A-not-B task?
Possible explanations include…
memory limitations - e.g., the length of delay in the A-not-B task
problems with inhibitory control associated with immaturity of the prefrontal cortex-
competition between a representational system and a response system
Physical knowledge
Knowledge of gravity begins in the first year
Infants have been shown to look longer at objects that violate expected motion trajectories: 7-month-olds are surprised to see a ball roll up a slope unaided (Kim & Spelke, 1992)
Infants also gradually come to understand under what conditions one object can support another
This gradually refined understanding of support relations is presumed to result from experience: between 3 - 12½ months, infants make progressively more complex judgements about what physical supports are possible (Baillargeon, 1998)
Developing of support relations
Diagram is The Violation that is detected at each age.
Where each age will be surprised at the items
<-6.5 months
<-12.5 months
The order in which children begin to understand how one object supports another
Understanding intention
Infants who see a human arm repeatedly reach for an object in the same location assume that the action is directed toward the object, not the place (Woodward, 1998
6-month olds looked longer when the hand went to the new object in the old place, than when it reached for the old object it had reached to before
Infants may attribute intentions and goals to inanimate entities as long as they “behave” like humans
In one study, 12- and 15-month -olds were introduced to a faceless, eyeless, blob that “vocalised” and moved in response to what the infant or experimenter did, thus simulating a normal human interaction (Johnson, 2003)
When the blob turned in one direction, the infants looked in that direction (following the blob’s “gaze”). Infants did not behave this way with a blob whose behaviour was not contingently related to their own
Attributing dispositional states
Most babies preferred the positive aspect. Prosocial
Twelve-month-olds also seem able, like adults, to attribute
dispositional states (Kuhlmeier et al., 2003)
Infants watched a film that adults interpret as a ball “trying and failing” to get up a hill as it is being “helped” by a triangle and being “blocked” by a square
Subsequently, with just the three shapes on the screen, infants looking behaviour indicated that they expected the ball to approach the helpful triangle while avoiding the hindering square
Conceptual knowledge
General ideas or understandings that can be used to group together objects, events, qualities, or abstractions that are similar in some way
Crucial for helping people make sense of the world
Nativists argue that innate understanding of concepts plays a central role in development - argue nature is responsible for dev
Empiricists argue that concepts arise from basic learning mechanisms-
Category hierarchies
A major way in which infants figure out how things in the word are related to one another is by dividing objects into categorical hierarchies (i.e., categories related by set-subset relations)
Learning category hierarchies
Categorical hierarchies often include three main levels (Rosch et al., 1976)
A very general one, the superordinate level (living things)
A medium one in between, the basic level (birds)
A very specific one, the subordinate level (parrots)
Children usually learn the basic level category first, as:
Objects at this level share many common characteristics (unlike superordinate level categories)
Category members are relatively easy to discriminate (unlike those in subordinate level categories)
Children sometimes form child-basic categories whose generality is somewhere between basic and subordinate level categories (Mervis, 1987)
“things that roll” instead of “balls”
Children use what they know about basic level categories to form superordinate and subordinate categories with the assistance of adults
Forming categories in the first year
Infants form categories of objects in the first months of life
Even 3- and 4-month-olds can tell cats from dogs (Quinn & Eimas, 1996)
A key element in infants’ thinking is perceptual categorization, the grouping together of objects that have similar appearances (colour, size, movement, etc.)
Often their categorizations are based on parts of objects rather then on the object as a whole (e.g., legs for animals, wheels for vehicles: Rakison, 2005)
developing conceptual categories
Babies (7 months) treated plastic toy birds and aeroplanes, which are perceptually similar, as if they were members of the same category
Babies (9 -11 months) treated toy aeroplanes and birds as members of conceptually different categories, despite the fact that they looked very much alike (Mandler & McDonough, 1993)