Today’s post comes from the book, The Introvert Advantage by Marti Olsen Laney, PsD. I think I’ve mentioned before (or at least intended to) the fact that according to Dr. Laney and others, introvert brains operate differently than extrovert brains. In brain function studies of introverts/extroverts, PET scans were used to determine the most active part of the brain based on blood flow. The results indicated that:
“…introverts had more blood flow to their brains than extroverts. More blood flow indicates more internal stimulation…
“Second, introverts’ and extroverts’ blood traveled along different pathways. Dr. Johnson found the introverts’ pathway is more complicated and focused internally. The introverts’ blood flowed to the parts of the brain involved with internal experiences like remembering, solving problems, and planning. This pathway is long and complext. The introverts were attending to their internal thoughts and feelings.
“Dr. Johnson tracked the fast-acting brain pathway of extroverts showing how they process input that influences their activity and motivation. The extroverts’ blood flowed to the areas of the brain where visual, auditory, touch and taste (excluding smell) sensory processing occurs. Their main pathway is short and less complicated. The extroverts attended externally to what was happening in the lab. “
These differing pathways for blood flow require different neurotransmitters. Extroverts rely on dopamine, a neurotransmitter associated with movement, attention, alert states and learning. Extroverts are not terribly sensitive to dopamine, though they require large amounts of it. Unfortunately, while the brain produces some, it’s not nearly enough. Thus,
“Extroverts need [dopamine's] sidekick, adrenaline, which is released from the action of the sympathetic nervous systems, to make more dopamine in the brain. So the more active the extrovert is, the more Hap[py] Hits are fired and dopamine is increased. Extroverts feel good when they have places to go and people to see.
“Introverts, on the other hand, are highly sensitive to dopamine. Too much dopamine and they feel overstimulated. Introverts use an entirely different neurotransmitter, acetylcholine, on their more dominant pathway…
“Acetylcholine…affects attention and learning (especially perceptual learning), influences the ability to sustain a calm, alert feeling and to utilize long-term memory, and activates voluntary movement. It stimulates a good feeling when thinking and feeling.
One of the results of all this, is that it takes introverts longer than extroverts to refill their energy well when it’s been emptied, because their nerve receptor sites are slow to re-uptake the neurotransmitter. So we need more time to recover and get tired more easily. Something I’ve been experiencing a lot lately. Fortunately, Laney devotes an entire chapter to dealing with this, but that’s a post for another day.