You Got Two Brains?

Dr. Paul D. MacLean (pronounced McLain) is the scientist who proposed humans have a Triune (3) separate but linked brain system. Based on evolution, McLean who passed on in 2007 at age 94, labeled the oldest brain the Reptilian Complex, the second oldest, the Limbic System, and the youngest, the NeoCortex.

Scientists have accepted the MacLean model as dividing our cerebral cortex into
an ancient evolutionary brain based on instincts, reflexes, and automatic responses.
No thinking, just reacting to hardwired programming.

The Limbic System is a separate brain involved in feelings and emotions. The hypothalamus is part of the Limbic and involved in hunger, thirst, pain response,
pleasure and sex. It controls the Autonomic Nervous System for pulse, blood pressure, breathing, and emotional arousal.

Limbic also runs the Pituitary (Master) Gland, releasing hormones for growth and
metabolism. It is intimately involved in memory through the hippocampus.

The youngest brain (NeoCortex) controls our consciousness, planning, thinking and language.


The three separate brains are integrated for decision-making, but our logical, reasoning analysis is often highjacked by our emotions and instincts. All major decisions we make have to pass the test of acceptability to our feelings, emotions,
and evolutionary instincts. They often exercise veto power over our thinking NeoCortex.

Google: Amygdala: emotional reactions, aggression and fear.
Google: Hippocampus for laying down new memories.
Google: Dr. Michael Gershon, The Second Brain, the Enteric Nervous System, the
brain in the gut (intestines).

Two Cerebral Hemispheres

Most of us have heard of our left brain, right brain complex. Our brain has the qualities of Localization and Lateralization. Our brain functions are specialized and often reside in a specific structure.

Brain Dominance

Our brain always uses both left and right hemispheres, but one is dominant.
Example: language, speech, reading, and comprehension are left-brain dominant.
See the chart below. Right-handed folks are left-brain dominant.

Left Brain Function Right Brain Function

1. Language, speech, memory, Pattern Recognition, comprehension, & Grammar Context, Intonation

2. Serial Processing Parallel Processing

3. Verbal Mental Imagery

4. Analytical Holistic

5. Linear Algorithmic Holistic Algorithmic

6. Logical, Reasoning Intuitive, Emotional

7. Math, Counting, Measuring Math: shapes, motions

8. Present & Past Present & Future

9. Music: Rhythm, Notation Melody, Intonation

· Communication between left & right hemispheres:
· Corpus Callosum, Anterior, Posterior Commissures
& Hippocampal Commissure
· Goal: integration between left & right hemispheres
· Brain Stem, Basal Ganglia & Dopamine: automaticity
· Central Thalamus: center for Consciousness
· Conscious Mind: 60-80 Bits of Information Per Second;
· Nonconscious Mind (Central Nervous Center): 11 million Bits of Information per second.
· Humans hardwired (programmed) to pursue Pleasure & Avoid Pain. See: Ventral Tegmental Area, Nucleus Accumbens, & Dopamine System are Pleasure Seeking structures and Neurotransmitters.

N.B. Humans are also Eye, Leg, and even
Side-of-The-Mouth dominant.


No one is totally left or right brained, but are left or right dominant. Left-brained folks (right-handed) and language
oriented, learn differently than Right-Brain dominant people.

Our right-hemisphere (brain) is visually dominant and right-brainers learn better through pictures, graphs, and pattern recognition than reading.


The science of left-brain, right-brain offers us a picture of the
functions of our brain structures. Lawyers tend to be left-brained, while engineers and computer technicians right-brained. Our goal is an integration of both hemispheres.

Would it help you ace school, and grab promotions in your
career if you could read three (3) books, articles and reports,
while your peers could hardly finish one?

How about permanently doubling (2x) your long-term memory? If you care, ask us how.

See ya,

copyright © 2008
H. Bernard Wechsler

Author's Bio: 

Author of Speed Learning For Professionals, published
by Barron's. Business partner of Evelyn Wood, creator
of Speed Reading, graduating 2 million, including the
White House staffs of four U.S. Presidents.