10/24/12

1

BRAINS ON FIRE

The Adolescent Brain

Dr. Hazel McBride Ph.D University of Toronto/OISE

Replaced by Aliens at Puberty!

Brain Under Construction

hormones

Secondary sex

chars.

Sex

Growth spurt

Brain structure

Rew

ard

defic

ienc

y

Emot

iona

l rea

ctivit

y

Family conflict

Epistemic angst

loneliness Stressful events

School transition

moodiness

relativism

Pee

r pr

essu

re

resp

onsib

ility

Drugs

Mixed emotions

Life choices

10/24/12

2

A period of both VULNERABILITY and OPPORTUNITY

•  Partly innate (genetics).

•  Individual differences in development.

•  Strongly influenced by experience (plasticity).

•  Especially the prefrontal cortex – a region undergoing huge change in adolescence (Giedd, J).

Two Phases of Adolescence •  “Starting the engines without a skilled

driver” (Dahl, 2001)

Dr. Rebecca Todd

Menarche ovulation

Spermarche Breasts: Finish Breasts: Start

Growth Spurt Weight spurt

Prefrontal Cortex Dorsolateral Prefrontal Cortex Matures

Temporal Lobe

Positive Affect

Negative Affect

Family Conflict: Frequency

Family Conflict: Intensity

Sarcasm Sensitivity to Stressors

Depressive Affect

Masking Emotions

Shame? Guilt? Anxiety? Mostly girls?

6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Red = Female

Blue = Male

EARLY MIDDLE LATE 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Menarche ovulation

Spermarche Breasts: Finish Breasts: Start

Growth Spurt Weight spurt

Prefrontal Cortex Dorsolateral Prefrontal Cortex Matures

Temporal Lobe

32% by 13 Onset of drinking

First intercourse

Peak prevalence of alcohol disorder

Onset of substance use

Onset of smoking

General increase in risk taking behaviours

25% by 13

Peak alcohol consumption

Marijuana 11% by 13

Greatest risk of HIV, STDs, and unwanted pregnancy

Red = Female

Blue = Male

EARLY MIDDLE LATE

Synaptic exuberance… and pruning

Dr. Rebecca Todd

Resulting in fewer, more efficient connections as the brain matures

10/24/12

3

Myelination

Neural circuits become much more complex.

The CEO of the brain. Governs   decision making   judgment   morals, ethics   problem solving   abstract thinking   hypothesis testing

Teachers and parents provide the blueprints. The brain has great plasticity. Experience sculpts the brain. Use it or lose it. Practice strengthens connections.

Frontal Lobe

Prefrontal Cortex

•  RED BLUE GREEN ORANGE

•  PURPLE PINK BROWN RED

•  BLACK BLUE ORANGE

•  GREEN PINK PURPLE

•  BROWN BLUE BLACK RED

•  RED BLUE GREEN ORANGE

•  PURPLE PINK BROWN RED

•  BLACK BLUE ORANGE

•  GREEN PINK PURPLE

•  BROWN BLUE BLACK RED

Teach Them to Think

10/24/12

4

Any type of instruction/thinking that changes behavior will be reflected in the ‘remapping’ of neural networks which is the essence of learning. (Goswami, 2006)

Parents and Teachers are Key Players Supervision

Scaffolding •  Modeling: Mirror neurons.

http://www.pbs.org/wgbh/nova/sciencenow/3204/01.html

•  Academic scaffolding: outlines, graphic charts •  Breaking tasks into small parts •  Giving immediate feedback •  Teaching metacognitive strategies •  Peer tutoring •  Cooperative learning •  Providing practice and review •  Instructing in the students’

zone of proximal development Assessment for Learning not of Learning

Corticosteroids

Disabilit

ies

Secondary sex

chars.

Poverty

Poor self esteem

Violence

Isol

atio

n/te

asin

g Aca

dem

ic pr

essu

re

Family conflict

Media

loneliness Stressful events

School transition

School failure

Test anxiety

Pee

r pr

essu

re

resp

onsib

ility

Drugs

Previous trauma

Life choices

Moodiness

10/24/12

5

Reward Deficiency Syndrome (Spear, 2003)

•  Dopamine: Modulates reward and reinforcement Relates to novelty-seeking and risk taking Highest lifetime levels in PFC during

early adolescence. •  Net result: reduced experience of reward •  Increased risk taking.

Depression Myelination:

Reward & Punishment   Adolescents use the frontal lobe for decision

making.

  Adults use the dentane located in the cerebellum.

  It is hypothesized that adults can do a risk/cost analysis.

  Adolescents respond only to the reward.

  The cerebellum - motor centre - develops. (dancing, sports, music).

  Also involved in higher level cognitive processes.

Cerebellum Teach Cost/Risk Analysis

Reward Get to keep driving the car.

Reward Can stay at party and have fun. Can give in to peer pressure.

Cost Must leave the party early and be home before 12. Must stand up to peer pressure

Cost Must give up car keys. Must take bus to school.

Choice A Choice B

10/24/12

6

Social Understanding Social Understanding

Facial Recognition Deficits

Adolescents have more difficulty than younger students and adults in recognizing facial expressions.

They often interpret neutral, sad, and stressed expressions as anger.

Increasing Social Understanding

Role play

Drama

Literature

Conflict resolution

Teaching courtesy & respect

Discussions http://www.mindhabits.com

Knowledge about their brains: metacognition

Self regulation Be explicit!

Emotion Regulation Deficits

Brain functions important for connecting gut feelings to more planful, contextual thinking are still under development.

The capacity for planning, regulation of emotions, and adapting to the social environment is still developing.

10/24/12

7

Emotion Regulation Deficits A teenager’s brain….

vs. an adult brain Implications •  Neurobiology should be one of many factors considered when trying to understand teen decision-making and behavior.

•  Teens need to be surrounded by caring adults and institutions that guide them in learning specific skills and appropriate adult behavior.

•  What teenagers do shapes their development - learning and positive experiences help build complex, adaptive brains.

•  More research is still needed to fully understand interaction of genetics and environment - what is plastic and what is fixed. Weinberger et al.

Hormones Hormones

Oxytocin: The bonding hormone is higher in females than in males. So while females find emotional !conversations calming, the tired male !brain needs to zone out all that !chatter in order to relax.!

10/24/12

8

Sex Differences

Differences in the time lines at puberty. The prefrontal cortex develops earlier in females than in males.

Males and females may solve complex problems differently.

Females activate more language-related brain regions.

Males activate more spatial-related regions.

Sleep Deprivation

Sleep Deprivation

The biological clock changes at puberty.

Most teenagers are sleep deprived.

Sleep deprivation interferes with learning.

They learn better later in the day.

What Next ?

Epigenetics.

fMRI twin studies.

fMRI studies of gifted students.

Studies of math interventions.

Diffusion tensor imaging. http://www.pbs.org/wgbh/pages/frontline/shows/teenbrain/view/