Lecture 1 - Intro & Neural Development

Question 1

why do we study development

Answer 1

• to understand when and how brain organisation emerges
• understand how pre-programmed processes and experience interact

Question 2

research methods

Answer 2

1. preferential looking - camera looks at where baby looks. can be gaze preferential
2. eye tracking - more detail info of looking patterns
3. psychophysiology - heart rate, pupil dilation, skin conductance
4. neuroimaging: EEG (electrical signals) NIRS (changes in light absorption related to oxygen uptake) structural MRI, functional MRI
5. experimental tasks
6. standardised tasks (e.g. NEPSY or ADOS)

Question 3

neural development

Answer 3

• postnatally brain undergoes structural changes linked to behavioural changes
• stuyding brain tells us about perceptual, cog and social dev
• but: a lot is still unknown, some believe studying these functions in the brain provides not useful info

Question 4

pre-natal neural development

Answer 4

• brain begins with a plate of cells in embryo which folds into tube
• by 24 days tube is developed with neural crest and central canal
• this tube becomes spinal cord with brain at one end. by 30 days brain begins to divide (hidbrain midbrain forebrain)
• ## after 30 days: midbrain, thalamus, cerebellum, cortex (dif layers which gradually differentiate)

Question 5

six stages of CNS development 2 months to birth

Answer 5

1. mitosis - cells divide to form neurons
2. migration - cells move along chem gr to their destination
3. differentiation
4. synaptogenesis - cells gradually form connections
5. apotosis (cell death)
6. synaptic rearrangement - synapses prunes and connections rearrange
   - driven by gene expression, proteins and chemical signalling
   - abnormalities in these processes = atypical brain dev e.g. down syndrome - premature differentiation = fewer neurons. due to DYRK1A overexpression

Question 6

neural development: post-natal

Answer 6

• brain quadruples in weight from birth to adulthood
• most neurons present at birth but connections develop. myelin keeps these together.
• synaptic growth and pruning depend on experience (infant has 2x many synapses & connections do not inc as much after 2 years)
• at adolescence there is pruning especially in pfc while visual not much
• visual deprivation has worse effects if occuring in infanthood than adult (binocular vision critical period = 3 years)
• 4 months of cataracts at birth can lead to deficits in pattern vision later (sleeper effects). children with cataracts need lots of dots moving coherently to see motion in one direction but without only need about 30% moving in same direction
• more residual plasticity in visual

Question 7

neural development: frontiers

Answer 7

• Brodmann’s areas classify based on cytoarchitecture
• specialisation is also functional
• interactive specialisation - there are genetically specified growth patterns where brain forms maps but can change due to experience
• interactions between regions sharpens functions and response properties of cortical regions

Question 8

faces

Answer 8

• children less localised & specialised area for processing faces:
  > Gathers et al. (2004) - 5-8 and 9-11 yr/olds have similar activation in fusiform gyrus but most selective for 9-11
  > Scherf et al. (2007) - in 5-8 FFA not selective for faces over objects so not specialised yet

Question 9

social brain

Answer 9

• kids more medial pfc activity
• adolescents thinking about intentions show more mPFC activity than adults
• WM connections at birth predict cog outcomes at 2 years (facilitates specialisation) e.g. frontal node important for sending info across brain. connections also predict motor outcomes
• adult-like structural connections (neurons often unmyelinated however) exist at birth (Zhao et al 2019)
• functional connections change, moving from visual-motor to frontal nodes by 2