2021 Adolescent Brain Development

Adolescent Brain Development & Implications on emotion & personality

PGA 102

Dr. Kimberley Kong

Learning Outcomes

• To learn about the main differences between an adult brain and an adolescent brain
• To relate how brain development influences behaviours, emotion and personality in adolescents

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Yes or No ?

Is your brain fully developed?

True or False?

Brain development in girls takes place sooner than boys

Boys' Brains are Bigger than Girls' (in general)

• At 6 years of age, brain achieves 95% of its maximum size
• Anatomical size of a boy's brain is bigger than a girl's.
• weak correlation between brain size and intelligence

Max size of brain does not imply max maturity ...................

Maximum brain size Maximum brain maturity The brain continues to develop

Typical Adolescent Behaviours?

Adolescent Emotion & Personalities

mood swing

high sense of self-consciousness

Rebellious

Adolescent Attitudes & Behaviours

New experiences

Seeks social connection

risk-taking! Sensation-seeking

cell bodies (somatic)

NERVE CELL (NEURON)

axon

dendrite

Newborns have 100 billion cells. Born with more than we need

myelin sheath

terminal axon

Neurons need to 'talk' to each other

• Neurons are connected to each other to form an extensive neural connection
• Each connection forms a 'synapse'
• Neural connections are arranged through 3 main processes
• proliferation, pruning, myelination

Brain Development Three different processes

• Proliferation - rapid development in the brain where neural connections are formed

• Pruning - connections that less / not used will be pruned away

• Myelination - neural pathways (axons) are sheathed with myelin to allow efficient transmission of signals

Brain Development is not done .....till around mid 20's

• Radical changes take place between 0-3 years & 9-14 years
• Structural changes and neural re-arrangement occurs during adolescence

Rapid brain development during early adolescence till mid -20s involve pruning dan myelination

1. Proliferation : Development of Grey Matters

Rapid development of grey matter in children (neural connection), reduces during adolescence

Grey matter peaks in girls at age 11, boys at age 13

Later, volume of grey matter reduces

movement

learning

planning

social/peers

pleasure

rasional thinking

emotion

vision

language

memory

synapse formation

breathing

1. Proliferation:

connection between different parts of the brain

2. Pruning: Reduction of Grey Matters

• Unnecessary connections are eliminated or pruned away
• USE IT or LOSE IT! (like muscles)
• increase network efficiency
• Adolescent brains highly 'malleable' (neuroplasticity)
• Adapt based on experience and environment
• Learning takes place most during this time

Wire together, Fire together

synaptic connections during childhood are double of what is in adult brain

3. Myelination: Development of White Matter

• White matter is myelinated axons
• Allows communication between the neurons
• White matter develops continuously from birth, peaks during puberty
• Increases soon after the peak of grey matter at age of 11 for girls, age of 13 for boys

3. Myelination

Neural network is made up of myelinated axons across trillions of connections all over the brain. Axons transmit messages to different parts of the brain to be processed. Less used connections will be pruned away

Adolescent Brain Development (12-19 years)

learning hub

memory centre

corpus callosum

reward centre

command centre

• Back to Front Development
• Basic to Complex
• Sensorial, emotion, cognitive
• Frontal lobe is the last to develop

fear factory

Structural Changes in Adolescent Brain (12-19 tahun)

Command Centre

Rasional thinking, planning, conflict management, judgement(last to develop)

Corpus callosum process information, creative ideas, open mind

pleasure/reward centernew experiences, sensation

nucleus accumbens

long term memory, new learning

Process emotion, fear, anger

Emotions are processed differently in adolescents

PFC

PFC

What is Amydala Hijack ?

amygdala

Read more

amygdala

Adolescent Brain

Adult Brain

• Depends largely on amygdala
• Fight or flight
• Wrongly intepret emotions
• Sensitive to social situations
• Easily stressed (mental health issues)

• Depends more on Prefrontal Cortex (PFC)
• Controls impulsiveness
• Make rational decisions
• Emotion control
• Self-control

Why are adolescents more prone to high-risk behaviours compared to adults?

Self-Control lags behind Sensation Seeking

• sensation seeking peaked in teenage years
• self-regulation peaked in 20's
• Owns a turbo charged Ferrari but no driving licence

Dare-devil brain .....sensation seeking

• Openness to new ideas, experience
• Huge potential to acheive great things, fearless
• Lack judgement, rational thinking, consequence of action
• Driven by pleasure and rewards

Russian Roulette - is it safe to play with one bullet??

Jisim kelabu meningkat mengikut corak linear. Corak ini sama dalam bahagian otak yang berlainan

Rewards, pleasure, sensation, new experiences

The part of the brain responsible for rewards, pleasure & motivation mature SOONER resulting in adolescents constantly seeking sensation & new experiences

Jisim kelabu meningkat mengikut corak linear. Corak ini sama dalam bahagian otak yang berlainan

Poor in judgement, rasional thinking

Prefrontal cortex responsible for logical thinking, judgement, self-control mature LATER. Compared to adults, adolescents are more likely to engage in high-risk activities, impulsive behaviours, with little consideration for their actions

• Road traffic injuries leading cause of death among adolescents
• Adolescents are 4x more likely to have car accidents compared to adults
• 3x more likely to die from car accidents
• 2x more likely if they are with 2 friends in the car
• 4x more likely if they are with 4 friends

Adolescents take higher risks when they are in the presence of friends

What is the cause of accident? lack of technical skills? Lack of judgement for consequences of action?

Plastic Brain....malleable & able to adapt

• High learning abilities
• Experience-dependent
• New neural connections
• Quick to learn new things
• Use it or lose it (pruning) makes learning efficient

Social brain .......peers, BFFs

• Fear of Missing Out (FOMO)
• Reward centre is matured
• Craves for social interaction (rewards)
• Friends is everything
• Social brain not connected to PFC - TROUBLE!

Adolescence is a sensitive period of development

• Double-edged sword
• Sensitive period for social brain development
• Highly sensitive to Social cues
• Easily influenced by peers
• Rewards and threats in social domain
• Highly sensitive to social rejection
• Great learner, adaptable. motivated
• YET, vulnerable period

Dare-devil brain

Social brain

Neuraplastic plastic

Adolescents & addiction

pleasure

• Smoking, drugs, pronography stimulate the reward centre
• Neural connection from reward centre to memory centre (hippocampus) becomes stronger over time
• Long term memory is formed
• Addiction sets in
• Brain craves for the same experience stored in memory to derive pleasure/reward

dopamine

All wire together, fire together

stronger neural connection

more dopamine

memory

addiction

Adolescents are owls

• Melatonin - hormon to induce sleep
• Adolescents 'turn on' melatonin 3 hours later at night compared to adults
• 'Off' 3 hours later in the morning
• Lack of sleep can affects different aspects of functioning

Adolescent sleep clock "pushed back"

Mood swing, stress, concentration and performance affected

How the Brain affects behaviour

credit: Daphna Shohamy, Columbia University, Zuckerman Institute

Implications on emotions & personality

• fail to consider consequences (eg covid party, russian roulette, drink driving)
• gut feeling behaviours, high-risk
• rebellious
• sensation seeking
• highly motivated for social relations
• easily influenced by friends
• addiction, substance abuse
• easily stressed
• able to learn quickly
• Open mind, creative, flexible

Summary

1. Brain achieves its maximum size during early adolescence
2. Brain continues to mature even after it is done growing
3. Adolescent brain is ready to learn and adapt
4. Many mental disorders may begin during adolescence
5. Adolescent brains are vulnerable to stress
6. Adolescents need more sleep than adults or children
7. Adolescents are highly resilient

THE END

May Your Brain Get Enough Sleep Tonight