Lecture 4 - neural development Flashcards
1
Q
What does neural development allow us to do?
A
- examine physical brain growth
- relate behaviour in development to the structures and networks which underpin it
2
Q
What are the 4 ways of measuring neural development?
A
- EEG
- FMRI
- MEG
- NIRS
3
Q
EEG?
A
- Tests electrical activity in the brain
- Very high temporal resolution
- Low spatial resolution
- Can be used in early infancy
4
Q
FMRI?
A
- Measures changes associated with blood flow
- Very high spatial resolution
- Requires stillness which can be tricky so can’t really use on infants
- Not appropriate if there is metal in the body
5
Q
MEG?
A
- Measures magnetic fields produced by the electrical currents in the brain
- Very high temporal resolution
- Requires some tolerance from the participant
6
Q
NIRS?
A
- Uses Near Infra-Red (NIR) light to measure light scattering and absorption allowing us to measure change in blood flow
- Trade off between spatial and temporal resolution
- Can be used early from about 3 months of age
7
Q
What is executive function?
A
mental operations that enable us to coordinate our thoughts and behaviour
8
Q
Cloth pulling task?
A
- a test of means-end behaviour
- 6-8 month old infants are presented with an object which they can only retrieve by pulling on a cloth
- 7 month olds would sometimes retrieve the object by chance
- 8 month olds demonstrated intentional means end behaviour
- this required them to execute a sequence of actions in the correct order = an executive function task
9
Q
Towers of Hanoi?
A
- task of planning
- one disk at a time, can never put a larger disk on top of a smaller disk
10
Q
Neural basis of executive function?
A
- it is strongly associated with the prefrontal cortex = a central executive
11
Q
A not B error?
A
- at 8-12 months the child makes a perseverative error, continuing to search at A after the object moves to B
- with age, errors decrease as does the delay period over which the child will search correctly
- this demonstrates difficulties in set-shifting, inhibition and working memory
12
Q
EF and the A not B error in moneys?
A
- Diamond (1990) showed that in monkeys, A-not-B task performance was governed by the PFC
- lesions of dorsolateral prefrontal cortex produced a profound deficit on the A-not-B task as long as any demand whatsoever was placed on memory
13
Q
EF and the A not B error in humans?
A
- Bell & Fox looked at infants who could and could not solve the A not B task using EEG
- found that individual differences in brain activity explained the differences in performance
14
Q
Shifting - the dimension card change sort?
A
- a test of attentional shifting
- 3 and 4 year olds asked to sort a stack of cards either by colour or shape
- Half way through the game, the rule changes
- Despite answering correctly to questions concerning the game ‘rules’ at 3 years children typically continue sorting cards with respect to the first dimension
- By 4-5 years they switch successfully
- They lack the ability to switch attention between aspects of the scene (colour and shape) - a central executive task
- At 3-4 years, executive function is still developing
15
Q
Shifting - the Wisconsin card sorting task?
A
- relates to flexibility, you don’t know the rules
- children do the task while brain activity is recorded via NIRS
- nearly all aged 5 but only 75% aged 3 successfully switch rules
- changes in blood oxygenation in prefrontal areas compare who pass vs fail
