Adolescent Brain

As we talk, take notes over important terms and research.

What is the brain?• An electrical system• Its neurons are specially suited to conduct

electrical signals.• “At any time, your brain is generating the

equivalent of about twenty-five watts of electricity- enough to power a light.” (Walsh 27)

Interesting Neuron Trivia• Baby arrives in world with about 100 billion neurons• Each of those neurons has an average of about ten

thousand branches• 100 billion neurons with ten thousand branches, make the

possible number of connections about one quadrillion.• At birth, only about 17% of neurons are linked.• In the years and decades to follow, the rest get wired

together.• Two forces drive the wiring of the brain: GENETICS and

EXPERIENCE.

Brain Neurons

• Each neuron has dendrites that receive signals, a cell body, and a long cable, or axon, extending from it.

• Electrical impulses travel down axons to axon terminals.

• If impulses are strong enough, then they cross the gap and signal dendrites on adjacent neurons.

Neurons: Firing and Wiring

The neurons that fire together wire together.

WHICH MEANS…

The MORE they fire together, the stronger the connections between the neurons will become.

The Latest Research

• Dr. Jay Giedd, National Institute of Mental Health, 1991

• Studied brain growth from ages 3 to 18• Found that from teens into twenties, substantial

growth occurs in the corpus callosum. • Also found that the prefrontal cortex goes

through a wild growth spurt that coincides with the onset of adolescence.

Other Important Brain Structures

• Neuroscientist Paul MacLean describes the human brain as being composed of three distinct brains all wired together to function as one: – Brainstem– Limbic system– Cortex (prefrontal cortex)

Brainstem

• Connects brain to spinal cord• Responsible for unconscious features like

breathing and heartbeat• Center for reflexes such as coughing, sneezing,

swallowing, vomiting

Limbic System

• from Latin limbus, meaning “ring”• Physically “rings” brainstem• Seat of emotion• Produces fear, anger, pleasure, sorrow, etc.• Prefrontal cortex can override limbic system

and cause us to rethink the situation, prevent us from acting out.

Limbic SystemImportant Parts:

AMYGDALA: Seat of fear and anger. Very active in the adolescent brain.

HIPPOCAMPUS: Plays key role in encoding new memories; determines what information will be sent to memory. An adolescent’s hippocampus can be even more damaged by drinking and drug use than an adult’s.

Cortex• Prefrontal Cortex• Prefrontal cortex can override the limbic

system response and cause us to rethink the situation, prevent us from acting out, allow us to control emotions.

• Phineas Gage

Prefrontal Cortex• Does the bulk of its maturation betweenages 12 and 20.

• Where most Sophisticated abilities Reside:

emotional controlimpulse restraintrational decision-making

“The prefrontal cortex is the seat of civilization.”(Dr. Karl Pribram, Radford University

“…the brain’s CEO…” (Dr. David Walsh)

Corpus Callosum

• Set of nerves thatconnects all the parts of the brain that must work together to function effectively.• Example: used in makinggood decisions• Critical to intelligence, Consciousness, and self-awareness.

REMEMBER…

The neurons that fire together wire together.

What skills become important to practice (fire) so that habits form (wire together), especially during adolescence?

• Emotional control• Impulse restraint• Communication• Relationships• Organization

Important Brain Processes

• Use it or Lose it• Blossoming and Pruning

Use it or Lose it Blossoming and PruningBrain needs to be Brain develops in fits and exercised to starts. Different parts of thedevelop! brain develop at differentRemember… the neurons that fire times. together wire together.

Blossoming and Pruning, con’t

According to research of Marian Diamond at UC Berkley:• At the beginning of a growth spurt, brain

overproduces dendrites (blossoming)• Experience causes neurons to fire • As they fire, the connections between cells get

stronger• Branches that don’t fire shrink, wither, and then

disappear (pruning)… “Use it or Lose it”

How will you help these areas “blossom”? What do you need to “use” or “lose”?

• How do you PRACTICE impulse control?• How do you PRACTICE building healthy

relationships… with friends, families, teachers, etc. ?

• How are you PRACTICING effective communication… in speaking, in writing, in conversation?

• How are you PRACTICING responsibility and organization?

How will you help these areas “blossom”? What do you need to “use” or “lose”?

• What happens when you spend hours alone in your room watching TV or playing video games when your mind is sensitive to relationship development?

• What happens when you fail to follow through on an assignment or project when your mind is sensitive to developing organization and discipline?

REMEMBER…

The neurons that fire together wire together.

What skills become important to practice (fire) so that habits form (wire together), especially during adolescence?

• Emotional control• Impulse restraint• Communication• Relationships• Organization

WORKS CONSULTEDBradley, Michael J, EdD. The Adolescent Brain. Yes, Your Teen is Crazy. Gig Harbor, WA: Harbor Press, 2003. Bradley, Michael J, EdD. Yes, Your Parents Are Crazy. Gig Harbor, WA: Harbor Press, 2004.Inside the Teenage Brain. 2002. PBS. December 2008.http://www.pbs.org/wgbh/pages/

frontline/shows/teenbrain>.Wallis, Claudia and Kristina Dell. What Makes Teens Tick. Time. 26 September 2008. Walsh, David, PhD. A Guided Tour of Their Brains. Why Do They Act that Way? New York: Free Press, 2004.