©Arlene R. Taylor PhD

Studies have identified factors that combine to influence one’s position on the EAI Continuum. One of those factors involves:

The thalamus, located above the brain stem, triages” incoming sensory stimuli and routes the data to decoding sites in the cortex. The Reticular Activating System (RAS) in the brain stem amplifies or reduces intensity of incoming sensory data—in some brains. The relative amount of amplification or reduction influences your innate position on the EAI Continuum.

The more the RAS reduces the intensity of incoming sensory stimuli, the more extroverted the brain tends to be and the more it craves significant levels of stimulation.

The more the RAS amplifies or magnifies the intensity of incoming sensory stimuli the more introverted the brain tends to be and the more it requires protection from stimulation.
 

x Extroverts 16%

68%

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Introverts 16%x

RAS reduces size and intensity (think "tabletop exercise" with miniature figures and objects)RAS magnifies size and intensity (think "bigger-than-life" with Jack-and-the-beanstalk figures and objects)
Can handle large amounts of data / stimulation – more resistant to punishmentCan become overloaded quickly by too much input – more sensitive to punishment
Tend to need lower doses of pain and sleeping medicationsTend to need higher doses of pain and sleeping medications

 

* Eysenck Personality Questionnaire. Extraverts/extroverts, according to Eysenck's theory, are chronically under-aroused and bored and are therefore in need of external stimulation to bring them up to an optimal level of performance. About 16 percent of the population tend to fall in this range. Introverts, on the other hand, (also about 16 percent of the population) are chronically over-aroused and jittery and are therefore in need of peace and quiet to bring them up to an optimal level of performance. Most people (about 68 percent of the population) fall in the midrange of the continuum, an area referred to as ambiversion. (http://en.wikipedia.org/wiki/Eysenck_Personality_Questionnaire) Accessed 12/13.