Psy 105 - Week 3
numerosity
an understanding of quantity
At what age do babies learn that the type of contact matters?
5 months
When do infants have mathematical reasoning for small addition or subtraction events?
5 months old
With the A not B task for searching how do different age groups perform?
8 months and under - Tend to fail with any delay. 9ish months: pass with short delay (2.5 seconds) but not long delay (5 seconds). 12 month olds: pass with longer delays (even up to 10 seconds).
What is some evidence that the A not b error is cauased by lack of development of executive functioning?
Adults with frontal lobe lesions do worse on the A not B task.
What is some new evidence in the A not B error about looking at the correct location.
After about 7.5 months infants look in the correct location, even though they reach to the wrong place - suggesting that they might have some understanding that the object is there, and not in the old location.
Abstraction principle
Any set of discrete objects can be counted
In the box and screen study if infant's don't have object permanence (and think out of view objects don't exist), what would the results look like?
Babies would look longer when the screen stops part way.
What is better ANS (small weber fraction) related to?
Better performance on standardized math tests longitudinally.
At what age to infants discriminate arrays of different approximate numbers and how can we prove it?
By 6 months and by loooking longer at novel numerosity, more interest in changing than constant numerosity.
Point to N task
Children asked "which is four" (looking at a picture of four vs six fish) and children respond randomly.
What did Piaget think that counting was?
Counting is a procedure that yields the exact numerosity of the set
What other animal has the ability to discriminate between looking time tasks?
Dogs show similar performance to 5-month-old infants on looking time tasks 9 out of 11 dogs looked longer at the impossible outcome.
Where is core knowledge also present?
Evidence that both core knowledge systems also present (to some degree) in non-humans.
What are our two "core knowledge" number systems?
Exact small numbers (object tracking) Approximate large numbers
What is one likely part of the brain that develops later that would account for the A not B error?
Executive functioning - A not B error result of immature pre-frontal cortex.
What is the ability to represent large exact numbers based on?
Experience and culturally created systems.
How did they test to see if babies think objects are bounded?
Had habituation fo a box over some lines and when they removed the box either showed the lines as continuous or fragmented - the fragmented result being suprising and doing looking time studies they found babies do think objects are bounded.
What did the box and screen study prove about object permanence?
Infants as young as 3 and a half months of age understand that objects continue to exist when hidden.
infants can discriminate small numbers but at what point do they stop discriminating?
Infants can discriminate small numbers, but the system breaks down with larger numbers - infants fail when there are 4 or more objects.
What is the more evidenced explanation for why infants commit reaching errors (rather than object permanence)?
Infants have competence but lack performance.
What did the looking time sutdy with dots show about infant's understand of 8 v 16 dots?
Infants looked longer at the unhabituated dot number suggesting that infants have an understanding of approximations and can differentiate between them.
How did they study the A not B error and change in posture.
Infants were trained to search in location A when sitting on their mom's lap then infants either stay seated when the experimenter hides the object or they switch to standing on their moms lap.
If infants have object permanence what would the results look like in the box and screen study.
Infants would look longer when the screen rotates through.
Executive functioning (a domain general process) develops what functions:
Inhibitory control, working memory, selective attention
Order irrelevance principle
Objects can be counted right to left and left to right
Does counting really mean that children know numbers?
Not necessarily.. children when asked "how many" can count correctly, but when asked "can you give me four of somethign" grab a handful without couting.
What are the three parts of object perception?
Persistence an identity - what happens when an object goes out of view. Unity and boundaries - which parts go with what? Occlusion - what is the shape of each object?
What people have no number system?
Piraha people
In the box and screen violation of expectation to test object permanence how was it a clever design?
The impossible event more similar to habituation because the screen would pass through the object - so it should be boring but it wasn't.
How would someone from one of these cultures with no words for numbers do on estimation tasks?
They do similar to people with number system words.
Explain the baby and the violation of expectation how they tested Piaget's theory of object permanence.
They had a screen rotate 180degrees and had the infant habituated. Then they place a box behind the screen. Infants look longer at the impossible events - Impossible event more similar to habituation because if the box is there then the screen should stop.
What do infants have to fight against to make the right decision in reaching tasks?
They have to over-ride propensity to reach to the same place that they have been reaching before (perseveration). They also have to pay attention only to parts of the task that are relevant to reaching, rather than to other things that are more interesting.
When are babies less likely to make the A not B mistake?
When they are in the standing position
Do other animals have ANS?
Yes, rats traind to press a lever a certain number of times to get food are approximately correct. Guppies swim to a part of enclosure with more fish.
By what age do 3-months old find it unexpected for a box to float un-supported?
by 3-months of age
stable order principle
counting principle that states that number names must always be counted in the same order
Cardinality principle
counting principle that the last number name denotes the number of objects being counted
one-one principle
each object is labeled by a single number word
How did they test for mathmatic reasoning for small addition and subtraction events
looking time studies with mice and a screen. Infants looked longer at the "wrong answer."
What area of the brain does executive function take place in?
pre-frontal area
WEber ratio
proportional difference between numbers
Approximate Number system (ANS) acuity is
ratio of smallest difference that can be detected.
Occlusion
what is the shape of each object