By age 14, the brain has grown to its full size.

However, the functions aren’t yet fully developed. Until age 25, the braining is undergoing a “remodel”. Think of it like a home being built. The structure is built, but more time is required to make sure all the parts of the home are set up and operating correctly to make the house a home.

The remodeling phase peaks during the teenage years, making this a critical time to not interfere with healthy brain development. These brain changes affect thinking and behavior in your adolescent or teen's brain and help explain why adolescents are more likely to:

  • Participate in risky behaviors
  • Have less impulse control
  • Be more reactive rather than proactive
  • Struggle to consider long-term consequences of choices.

Here's what each part of the brain is responsible for:

  • Frontal Lobe

  • Parietal Lobe

  • Occipital Lobe

  • Temporal Lobe

  • Cerebellum

  • Frontal Lobe

    • Personality characteristics
    • Decision-making
    • Movement
    • Recognition of smell
    • Speech ability (contained by Broca's area)
    • Contains the pre-frontal cortex which is

    Prefrontal Cortex

    Located within the frontal lobe

    Cognitive functions such as:

    • Reasoning
    • Decision making
    • Problem solving

    Controls the release of neurotransmitters the impact one's mood, such as:

    • Dopamine
    • Norepinephrine
    • Serotonin

  • Parietal Lobe

    • Object identification
    • Spatial relationships (where one's body is compared with objects around the person)
    • Interprets pain and touch in the body
    • Helps the brain understand spoken language.

  • Occipital Lobe

    • Processes visual information from the eyes, including color, form, and motion.
    • Supports the brain in understanding language, storing memories, and recognizing places and faces.

  • Temporal Lobe

    • Short-term memory
    • Speech
    • Musical rhythm
    • Smell recognition

    Hippocampus

    Small structure within the temporal lobe; near the temples and ears

    • Memory and learning
    • Spatial memory

    Amygdala

    Located within the temporal lobe, just in front of the hippocampus

    • Associated with the brain's reward system
    • Stress
    • The "fight or flight" response with that is perceived.

  • Cerebellum

    The cerebellum, also known as the "little brain," is responsible for movement and balance, posture and motor-learning skills through coordination of multiple muscle groups. This part of the brain also plays a role in language development and assists with vision and eye movement.

Brain Circuits

Brain Circuits are the pathways in the brain formed by interconnected neurons where signals travel from one neuron to another.

Different brain circuits involve different combinations of neurons and neurotransmitters, leading to the brain's ability to communicate with muscles in the body; this impacts the function of the organ systems.

NEUROTRANSMITTERS

Neurotransmitter systems are the chemical messengers that carry information through the nervous system.

The nervous system is responsible for the brain, spinal cord and nerves that send signals between the brain and the body's functions. They play a key role in functions varying from:

  • Movement
  • Sensation
  • Heartbeat
  • Response to different environments

Neural Circuits

Neural Circuits are a network of interconnected neurons that work together to perform a specific function. The human brain has 86 billion neurons, and each neuron has about 10,000 inputs.

Neurons do not function in isolation, so they organize into circuits that process specific kinds of information; this impacts how the body moves, our reflexes, and our sensory responses.

So, what’s happening in the brain at this time?

During this development stage, connections in the brain (white matter) are being strengthened, while unused connections (grey matter) are being shed. This first begins in the back of the brain. The front of the brain—including the prefrontal cortex which is responsible for attention regulation, memory and response—is the last part of the brain to complete this process. 

As the front of the brain develops, adolescents and teens rely on the amygdala to make decisions and solve problems. The amygdala is the part of the brain associated with emotions, impulses, aggression and instinctive behavior. When the brain relies on the amygdala the following behaviors may be more likely: 

  • Choosing high-risk activities and behaviors
  • Expressing more and stronger emotions
  • Making impulsive decisions
  • Experimenting with substances