Reptilian complex
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Reptilian complex or R-complex is a part of the triune brain model ('tri', as in 3 part) proposed by Paul D. MacLean. This theory seeks to explain brain function through the evolution of existing structures of the human brain. The triune brain consists of : 1. The R-complex (also known as and the "brainstem"), 2. The Limbic system and 3. The neo-cortex.
The theory, observable through the fossil record, animal phylogeny, as well as during the stages of mammalian and human prenatal development, states that the mammalian brain's evolution depended on and was strengthened in structure and functionality through a series of evolutionary plateaus, which correspond startlingly well with animal groupings on earth.
Mammalian brain structure exists in the outer, highest sphere of the brain, where evolution is newest and younger. These areas are the Limbic systems and neo cortex. The Limbic system, which he first introduced by MacLean in a paper in 1952, is similar to the brain of lower mammals and is the source of emotions, some aspects of personal identity, and some memory functions. The Limbic system is composed of the amygdala and the hippocampus. The neo-cortex, also known as the cerebral cortex, is similar to the brain of higher mammals and controls higher-order thinking skills, reason and speech. Memory, art, literature, prolong childhood with learning vital to survival, and caring for family are some of the higher level brain activities which mammals have used to rise to such global prominence in such a short evolutionary time.
The brainstem and other lower brain parts controls normal animalistic behavior that the conscious mind does not, such as cardiopulmonary function, and is found in all vertebrates. In between these two brains, lies the R-complex.
The R-complex is named for the most advanced part of the brain higher mammals share with reptiles. It is responsible for rage, xenophobia, basic survival fight-or-flight responses, territoriality, social hierarchy, and the desire to follow leaders blindly. Often, this portion of the brain can take over rational brain function and result in unpredictable, animalistic behavior in even the highest of creatures who still bear this evolutionary baggage, humans included. The advanced neo-cortex can monitor R-Complex activity in sentient beings. The Reptilian complex is the most ancient part of a very successful brain scheme, evolutionarily speaking.
[edit] See also
[edit] References
Sagan, Carl. The Dragons of Eden; Random House, New York. 1977
