1
Q
What does the nature versus nurture debate address?
A
the extent to which congition and behaviour (brain development) can be attributed to genes or environment
2
Q
what is ‘nature’ ?
A
genetic blueprint (things we are born with)
3
Q
what is ‘nurture’ ?
A
role of experience
4
Q
Who originally thought that development is based on nature and what did he say?
A
Francis Galton - geniuses are born not made
5
Q
Who believed that development was based on nuture ?
A
- Freud - the role of early experiences
- Vygotsyky - the role of culture
- Skinner - we learn through reward and punishment
6
Q
what do we now know about the nature vs nurture debate ?
A
no easily distinguishable between them, it is a two way interaction
i.e. enivornment can trigger certain genes
7
Q
What was Piaget’s theory and what does it emphasize?
A
- basis for neuroconstructivism
- interaction between environment and genetic factors
role of both nature and nurture
8
Q
What is neuroconstructivism?
A
emphasises the role of brain development and experience in shaping congition and behaviour
emphasises both nature and nurture
modern version of Piagets theory
9
Q
what is the blueprint analogy ?
A
each connection in the brain is specified by our genes
highly unlikely as many connectiosn and wouldn’t be a good use of genetic code
10
Q
what is the predetermined developemnt theory ?
A
assumes genes enable function, and function leads to experience
genes-> brain structure -> brain function -> experience
e.g. codes how neurons form and some connections but not predetermined connections so gives space to experience and the environment
11
Q
what is the probabilistic development theory ?
A
emphasises reciprocal connection between each stage (2 way connection)
genes <–> brain structure <–> brain function <–> experience
this is the modern view
12
Q
what can we related the probabilistic development theory to and why?
A
epigenetics, experience can effect genes
13
Q
What is epigenetics?
A
The study of how the environment can turn on and off different genes
14
Q
What is the modern view of brain development?
A
Probabilistic development, emphasizing reciprocal connections between genes, brain structure, function, and experience
15
Q
What happens during the first two or three weeks of life post-conception / prenatal brain development?
A
- cell division
- cell specialization
16
Q
what is the proliferate zone ?
A
in prenatal development when neurons and glial cells are produced
17
Q
What forms the basis of the nervous system during prenatal development?
A
neural tube formation: a tube that folds from a groove in the embryo
around 3 weeks after conception
18
Q
where is the proliferate zones in prenatal development ?
A
inside the neural tube
neurons divide inside this tube and then migrate towards final location
19
Q
How many neurons are estimated to be produced per minute during prenatal/early development?
A
Around 250,000 neurons
20
Q
how do cells in the neural tube get to their final migration ?
A
- guided migration
- molecular signals
21
Q
where does the folded cortex emerge from ?
A
- having lots of neurons (physical constraint = convoluted surface)
- pattern of gyri/sulci pulled into shae by tension of axon bundles (white matter tracts)
22
Q
what does evidence from mice contribute towards the shape of the brain ?
A
- in mice that produce extra neurons they have a more convulated surface (more folds)
- convoluted structure based on physical constaints
23
Q
how do networks in the brani form during early/prenatal development ?
A
form based on habbian learning
24
Q
what is hebbian learning ?
A
spontaneous electrical activity enables networks to form (e.g. electrical activity in the retina helps form the visual pathway (doesn’t use a light stimulus))
25
what is the average weight of a newborn brain ?
450g (vs. 1400g in adults)
26
when are the majority of neurons formed in the brain ?
prior to birth
27
What is synaptogenesis?
The formation of new synapses in the brain, which allows the brain to grow
28
what does the rise and fall of synapses in life show ?
- rise - lots of new synapses formed soon after birth
- fall - pruning where we lose synapses because they are not important
29
What is the significance of synaptic pruning?
Elimination of unimportant synapses to enhance brain function
30
What happens to synapse formation after birth?
There is a rise and fall pattern in synapse formation for differnt brain regions
- visual cortex peaks early
- prefrontal cortex peaks later and plateus later
31
What is the last area of the brain to achieve adult levels of myelination?
The prefrontal cortex
32
True or False: More synapses always mean that brain areas function more effectively.
False
33
What is the role of spontaneous electrical activity in brain development?
It enables the formation of neural networks, such as the visual network
34
What are the primary mechanisms for brain growth after birth?
- Synaptogenesis
- myelination
- glial cell proliferation
35
What does the term 'guided migration' refer to in brain development?
The process by which neurons migrate to their final locations
36
What is fine-tuning in the context of brain development?
The process of optimizing synaptic connections to enhance brain efficiency
## Footnote
Fine-tuning involves the reuse of synapses rather than just increasing their number.
37
what is myelination?
- myelin sheath increases in size
- increases speed of informatin transmission
38
what is the last brain region that achieves adult level myelination during development ?
prefrontal cortex
39
What are glial cells and their significance in brain development?
Non-neuronal cells that support and protect neurons, proliferating during early life and help with functioning
40
What does postnatal development refer to?
The process where infants and children gain new experiences leading to structural brain changes
## Footnote
thse changes can be visible
41
what is plasticity ?
experience dependent change in neural functioning
42
What was observed in the study where adults learned to juggle?
- An increase in gray matter density in areas related to vision and hand-eye coordination
| shows plasticity
## Footnote
Gray matter density decreased somewhat after participants stopped practicing.
43
what does an increase in gray matter mean ?
new synapses, dendrties, axon collaterals, glia cells are forming
## Footnote
no new neurons formed
44
Does increased gray matter always correlate with better cognitive ability?
No, increased gray matter does not necessarily indicate improved cognitive function
45
what evidence do we have that increased gray matter does not lead to increased congitive ability ?
Congenitally blind individuals have more gray matter in visual areas than sighted individuals, despite not being able to see
## Footnote
congenitally blind = born blind
46
what is functional brain plasticity in early development?
when prenatal brain damage can lead to major reorganistion of tracts
47
How does functional brain development vary across abilities as we grow?
Different types of abilities and knowledge change as the brain develops
## Footnote
Brain structure is not fixed and can reorganize after injuries.
48
What is the significance of the case study involving a 10-year-old girl with only a left hemisphere?
The left hemisphere adapted to process visual information typically managed by the right demonstrating brain reorganization, allowing her to process information from both visual fields despite missing the right hemisphere
## Footnote
she could see like a normal person
49
what are the limits of functional brain plasticity ?
- time limit (temporal) = critical or sensitive periods
- spontanoeus electrical activity enables networks to form prenatally and these won't be fully lost if reorganisation happens
50
what did konrad lorenz study ?
- how birds recongise their mother (filial imprinting)
51
What does the term 'filial imprinting' refer to in the context of brain development?
the process by which young animals learn to recognise the parent
52
when did konrad lorenz suggest filial imprinting occurs and why was this impotant?
- between 15h and 3 days
- the process is crucial for survival and has sensitive and critical periods
53
What are critical and sensitive periods in brain development?
Time frames during which certain types of learning must occur for optimal development or survival
54
what are the two main features of critical and sensitive periods ?
1. learning takes place within a limited time window
2. this learning is hard to reverse by later experience
55
What happens if imprinting doesn't occur within the critical period?
The opportunity for imprinting may extend if the suitable experience or person is absent
## Footnote
Birds can imprint to moving objects beyond the initial time window if no suitable figure is present.
56
what is meant when in critical periods learning is hard to reverse by later experience ?
- once chicks imprint to one object they can genralize to similar objects (colour or shape)
- but sometimes preference can be changed after sensitive periods
57
What is an example of a sensitive period in humans ?
- phonemic discrimination e.g. between 'r' and 'l'
- Infants lose the ability to differentiate between or produce phonemes if not exposed to that language early
## Footnote
typically need to be exposed in first year of life
58
what are the two possible explanations of critical/sensitive periods ?
1. (biological) genetically programmed synaptogensises (readies brain for learning), followed by reduced plasticity (learned information is 'fossilized')
2. closure of window could be initiated by learning itself i.e. an environmental cue
59
What is the first, and biological, explanation for sensitive periods?
A strict maturation timetable where neurons form during postnatal development which enables learning and connections are pruned as development progresses which stops learning happening
60
what is the second, environmental, explanation for critical/sensitive periods ?
neurons are waiting for a suitable experience, and exposure to experience closes the window for learning
## Footnote
e.g. particular gene plays a role in filial imprinting and in ducklings it is switched off after exposure, but can be extended which shows brain is waiting for experience
61
what is a human example of critical/sensitive time periods possibly being explained by the closure window being intiiated by learning itself ?
infants born with cateracts can't see much, but once removed and exposed to visual experience visual acuity increases quickly, and this can happen after 9 months and catch up to normal developing peers
## Footnote
may not exactly develop in the same way but doesn't mean they won't be able to see at all
62
what is the empiricist vs nativist view on innate knowledge ?
- empiricism: newborn mind is blank
- nativist: we are born with some knowledge
63
what is the modern view on innate knowledge and what does it refer to?
the readiness to learn and aquire knowledge (knowledge is not innate but innate mechanisms to learn)
## Footnote
e.g. imprinting mechanism is innate learning mechanism, but content of mechanism(to human or circle) is based on experience
64
what evidence was provided from an animal study using cats show for this inante readiness to learn ?
- development of cat visual cortex is the same whether they can see normally or in the dark (no visual experience)
- still shape (neuron) orientation selectivity in the same way
- but later on without visual experience orientation selectivity is lost compared to cats that can see and deonstrated more fine-tuning
65
What does the visual cortex of newborn cats reveal about innate knowledge?
It shows orientation selectivity develops similarly regardless of visual experience in the first three weeks
## Footnote
Later visual experience fine-tunes this selectivity.
66
what is an example of humans showing innate learning mechanisms ?
- infants prefer sweet taste: evolutionary advantage as nutritious
- infants prefer to look at patterns instead of gray surfaes which may help fine-tune the visual system
67
What is a method used to investigate brain structure in infants?
- Ultrasound
- prenatal MRI
## Footnote
These tools can identify major brain areas and developmental progress
68
why can we use a prenatal ultrasound to investigate the brain structure ?
different types of tissue (skull, grey matter, white matter, CSF fluid) all have differnt physical properties and we can create a STATIC map from this
69
How can researchers infer brain function in infants?
By observing their behavior
## Footnote
This helps to compare infant brain functions to those of adults.
70
what is an example of a behavioural method used to infer brain development in infants ?
preferential looking paradigm to see how far their visual system has developed
71
What is the purpose of behavioral methods in studying infant brain function?
To infer brain activity based on infant behavior patterns.
72
What is the preferential looking paradigm?
A method to determine what types of patterns infants can differentiate.
73
What functional neuroscience methods can be used with infants?
* EEG
* fMRI
* FNIRS
74
what are functional neuroscience methods used to investigate in development ?
temporary changes in brain physiology associated with cognitive processing
75
What is a challenge when using fMRI with infants?
Infants cannot be asked to stay still or perform tasks.
76
what does an EEG measure ?
- electrophysiology response (electromagnetic fields generated in the brain)
## Footnote
measure event-related potentials
77
How is EEG adapted for use with infants?
- Using an infant-friendly cap that allows for quick preparation
- infant friendly stimuli
- more breaks during study
78
what is the difference between adult and infant ERPs ?
- some adult ERPs are present in infants but delayed e.g. visual ERPs
- some ERP components only present in infants/toddlers
79
What component is linked to face processing in ERP studies?
N1 or N170 component.
## Footnote
around 300ms later in infants vs 170ms in adults
80
what is an ERP component only present in infants/toddlers and when is this present?
- NC negative central peak
- around 300-700 ms after stimulus onset
81
what is the NC component driven by and what does this mean ?
- driven by attention, bigger NC peak if more attention
- can reflect preferential looking e..g bigger peak for mother face than stranger's face
82
why are fMRIs not ideal for use with infants ?
- highly sensitive to movement
- loud, restrictive environment
## Footnote
but there has been some attempt with headphones
83
What might cause the delayed processing of ERP components in infants?
Lack of myelination.
84
What is the central negative component in ERP studies?
A component driven by attention, showing larger peaks for more attended stimuli.
85
What do fNRIS measure?
- it measures BOLD signal changes (blood oxgyen-level-dependent contrast)
86
how do fNRIS measure BOLD ?
uses the near infrared spectrum of the light
## Footnote
just above visibile spectrum of light
87
what does fNRIS stand for ?
functional near-infrared spectroscopy
88
What type of light does FNIRS use?
Near-infrared light.
89
why do fNIRS use near-infrared light ?
- skin, tissue, bone are mostly transparent to NIR light
- Hb (haemoglobin) and deoxyHB absorbs NIR
90
what equipment is included in fNIRS and how do they work to measure BOLD?
- emitter: emits NIR light
- detector: detect NIR light
Hb and deoxyHb absorb NIR light, then from the difference between emitted and detected NIR we can compute BOLD
91
what do fNIRS measure ?
measure changes in concentration of oxyHb and deoxyHb focally, related to brain activity
92
what are some advantages of fNIRS ?
- portable
- more tolerant of movement
93
What are some limitation of FNIRS compared to fMRI?
- low spatial resolution
- only surface fo cortex can be imaged
- often only a few sensors are used above a cerain brain area
94
How does fNIRS detect brain activity?
By calculating blood flow based on the difference between emitted and detected light.
95
What makes FNIRS portable and more suitable for infants?
It is less sensitive to movement and can be used on the head of infants.
Cognitive Neuroscience
flashcards
Decks in class (12)
# Cards
-
Methods in Cognitive Neuroscience42
-
The Lesioned Brain87
-
Music and the Brain105
-
The developing brain95
-
The social and emotional brain 173
-
the social and emotional brain 271
-
The Remembering Brain 189
-
The Remembering Brain 240
-
The Speaking Brain 155
-
The Speaking Brain 287
-
The Executive Brain71
-
practice5
