The Hidden Gifts of the Introverted Child (6 page)

1. Reticular Activating System
—Activator: Dopamine activates alert alpha brain waves, “hap hits,” and triggers the Back Attention System which notices any movement.

2. Hypothalamus
—Master Regulator: Regulates basic body functions and triggers the “Give It the Gas” system.

3. Right and Left Back Thalamus
—Relay Station: Increases and relays external sensory input to higher association areas.

4. Right Back Insular
—Integrator: Integrates several regions of the brain including the “where” and “when” visual, and the faster auditory pathway.

5. Left Amygdala
—Threat System: Triggers fear, anxiety, and anger if a real or perceived threat. Dopamine initiates acting without thought.

6. Right and Left Front Cingulate Gyrus
—Social Secretary: Party central; stops or starts speaking, triggers interest in others, shifts attention quickly for good cocktail party skills. Focuses on the outside world, pleasure, and what’s new and exciting. Based on emotional signals, the automatic nervous system and speaking are started or stopped.

7. Right and Left Temporal Lobes
—Processor: Processes and integrates emotions, external sensory input, and learning. Working memory operates here. Sends messages up to the motor area to move muscles.

A little understood but highly important fact is that acetylcholine activates another reward system. It’s subtle, but very powerful. The acetylcholine pathway travels from the brain stem, stimulating aspects of hearing and seeing linked to learning, all the way up to the executive brain functions in the frontal lobes. It travels a feedback loop between the brain and the body’s “Put on the Brakes” system. Researchers found that rats will give up food and sex in order to be stimulated on the acetylcholine pathway. When human brains are stimulated by acetylcholine they feel alert, enjoy what they’re doing, and are more relaxed. When we’re using our noodles, acetylcholine releases potent but delicate “hap hits” (a term happiness researchers use for feelings of satisfaction and enjoyment). This explains why some introverts derive profound satisfaction from studying, say, a single type of beetle for their entire life. For extroverts this mild reward is hardly noticeable.

Dopamine is most commonly known as the major reward pathway in the brain, influencing a number of powerful dopamine reward routes. Extroverts primarily travel on one of the dopamine pathways that releases extremely gratifying “hap hits.” These rewards promote novelty-seeking behavior, quick actions, and the urge to move quickly in order to get more of them. Dopamine pathways can promote addiction, because they release quick, intense zaps of elation. For introverts, however, a jolt of dopamine can cause anxiety and overstimulation.

Innie and Outie Pathways

Debra L. Johnson and her colleagues conducted a brain-imaging study using positron emission tomography (PET) on the brain activity of people with established introverted and extroverted temperaments. Their findings, which were published in the
American Journal of Psychiatry
, showed that extroverts and introverts had different amounts of blood flowing to different regions of the brain. Extroverts had lower blood flow in the behavioral inhibition system in the frontal lobes, but more activity in the
back
of the brain, in areas that underlie an intense thirst for sensory and emotional stimuli. Introverts had
higher blood flow in the
frontal lobes
—home to the system that inhibits behavior and promotes planning and thinking before acting.

Dr. Johnson and other researchers provide us with a detailed map of the acetylcholine and dopamine pathways involved. (
Note
: The illustrations and descriptions depicting these on
page 28
–29 are highly simplified.)

Put on the Brakes or Give It the Gas

“
Every
body
has a story
.” —
From the TV show
, Dr. G: Medical Examiner

The brain is a ball of electrical activity. As children grow, their brains harness and organize all the electrical activity by creating pathways and networks that stop and start thoughts, feelings, and behavior. Remember how your infant waved his hand around and finally was able to grasp a sippy cup? As pathways are developed, they increase the child’s ability to focus energy so he can gain physical, intellectual, and psychological control.

As children grow, they gather sensory input from their bodies and the environment, evaluate it, and generate more sophisticated and appropriate responses. An appropriate response could be taking external action like running, walking, or speaking; an appropriate internal action would be to have an idea, thought, or feeling. The brain and body are always attempting to balance the need for responses to be fast or accurate. Responses are carried out with the help of the three branches of the nervous system. The Central Nervous System consists of the brain and the spinal cord. The Peripheral Nervous System is a group of nerves looping messages from the body to the brain and back again. And the last branch is the Autonomic Nervous System which controls out-of-awareness body functions. The brain processes enormous amounts of information, and based on its evaluation of the need for speed and/or accuracy, it zips instructions to the body about how to respond via the spinal cord to the two branches of the autonomic nervous system.

THE ACTIONS OF THE AUTONOMIC NERVOUS SYSTEM

Each side of the nervous system has opposing functions that work outside of awareness, controlling many essential body reactions. The “Put on the Brakes” system triggers slower-acting nerves that target specific organs. Muscles relax, norepinephrine and energy are stored, food is metabolized, waste excreted, and mating can occur. Acetylcholine increases blood flow and activity and alertness in the front of the brain
.

Fast-acting nerves signal the “Give It the Gas” system. The torso and limbs spring into action for fight, flight, or fright. Oxygen increases, glucose energizes muscles, norepinephrine and adrenaline are released for fuel. Thinking areas are turned off, but dopamine increases alertness in the back of the brain
.

The
autonomic
(meaning “self-governing”)
nervous system
coordinates the body’s self-regulating functions such as heartbeat, digestion, and breathing. This frees the brain to manage sight, speech, hearing, thinking, emotion, and voluntary movement.

There are two branches of the autonomic nervous system: the
parasympathetic
and the
sympathetic
. The parasympathetic nervous system is our restoration side; it’s your child’s “Put on the Brakes” system. The “fight, fright, or flight” sympathetic nervous system is our action side. It is your child’s “Give It the Gas” system. The two sides work in opposition to each other, and when one is turned on the other is usually turned off.

Outies are more comfortable on the “Give It the Gas” side, and innies are more at home on the “Put on the Brakes” side of the nervous system. You can observe the difference when you correct your kids by saying no. When an innie is extroverting, she is excited. Let’s say your daughter grabs her sister’s ball and you respond with a firm, “No, give it back.” Her emotional gearshift applies the brakes; she slows down and gives back the ball. The sensation of slowing down is familiar to her. If you say no too harshly or too often, however, it may shut her down too much. After such rebukes, an innie would be neither motivated nor willing to waste her energy to shift up to the more stimulating (and uncomfortable) “Give It the Gas” side of the nervous system.

If an outie is excited and you say no when he grabs a ball, he may have more resistance to stopping. He doesn’t like the feeling of the “Put on the Brakes” system. However, if you don’t set limits, he won’t develop a well-functioning emotional gearshift. He won’t be able to calm himself when he overdoes it, or when he needs to adjust to others, or needs to rest. If he has to be limited quite often, it’s important to redirect his energy, lest it turn into anger and rebellion. Physical activities like shooting hoops, jumping on a trampoline, or throwing a ball are good outlets.

The Innie Brain and Body Tract

“
The chief function of the body is to carry the brain
.” —
Thomas Edison

Innies’ brains are very active. They have more blood flow and higher activity in the frontal lobes, and they are using faster beta brain waves. The acetylcholine pathway is long, and it requires overnight processing to store and retrieve information. This pathway arrives at the emotional center (the amygdala) last, so innies usually have delayed emotional responses. It turns on the “Put on the Brakes” system so that the body isn’t using as much energy, allowing the innie to conserve energy since his brain is burning up fuel fast.

Innies have busy brains, so they tend to
:

• Reduce eye contact when speaking

• Increase eye contact when listening

• Surprise others with their depth of knowledge

• Shy away from external attention or stimuli

• Appear glazed or zoned out when tired or stressed

• Have trouble turning off their brains to sleep

Innies travel the l-o-n-g acetylcholine pathway, so they are likely to
:

• Start talking in the middle of a thought

• Have active internal voices

• Use the preplanning and planning functions of the brain

• Use the more time-consuming emotional and decision-making areas of the brain

• Enjoy the familiar

• Learn best in context

• Have a good sense of humor, although only close people may see it

• Look to internal rewards

• Have vivid dreams and talk about them

• Turn off outside world when concentrating

• Have to hunt for words, especially if they are tired

• Have good memories if they learn to retrieve the information

• Seem to forget what they know

• Converse with people in their heads, perhaps thinking they said something out loud when they didn’t

• Be clearer about their perceptions, thoughts, and feelings after sleeping on it

• Experience some things as personal

• Get “hap hits” when concentrating on something of interest

• Write or talk to a trusted person to become conscious of all of their thoughts and feelings

The activation of the “Put on the Brakes” system means that innies
:

• May be hard to get going in the morning

• May freeze under stress

• May walk, talk, and eat slowly

• May have a soft voice

• Need time to ease into new situations

• Hesitate and can say no to themselves

• May need to regulate body temperature and protein intake since they are almost always metabolizing food and blood flows to their core organs and away from their extremities

• Must have breaks in less stimulating environment to restore energy

• May have cooler hands and feet (may need to wear socks to stay asleep at night)

• Usually keep their body still to conserve energy for deep concentration

• May notice pain more because they are more aware of their internal body sensations

• Appear relaxed, calm, but alert

• Can be territorial—people physically close to them drain their energy

• Enjoy social events but feel drained by them

• Are alert and observant

The Outie Brain and Body Tract

The brain of an extrovert has less internal stimuli than that of an introvert. Therefore outies are constantly scanning the outside world to gather new stimuli. They need lots of input to fuel their quick reward system—they tire of the familiar easily. Their chemistry triggers the “Give It the Gas” system, and they’re off to the races.

Outies are constantly seeking new input, so they tend to
:

• Dislike too much downtime—need action

• Increase their eye contact when speaking and lessen it when listening