Reptilian complex

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Reptilian complex or R-complex is a part of the triune brain model proposed by Paul D. MacLean. The model suggests that the human brain is divided into three sections, each corresponding to a stage in our evolutionary history. The reptilian complex, the oldest of these, is believed to be responsible for aggressive behavior, dominance, territoriality, and ritualistic and habitual behavior.

Overview[edit | edit source]

The reptilian complex, also known as the basal ganglia, is the name MacLean gave to the base of the brain, which includes the brainstem and the basal ganglia. He proposed that this area was responsible for 'primitive' survival instincts such as aggression, dominance, territoriality, and ritualistic behavior. This part of the brain is thought to have developed hundreds of millions of years ago, in our early reptilian ancestors.

Components[edit | edit source]

The reptilian complex consists of the brainstem and the basal ganglia. The brainstem is responsible for basic vital life functions such as heart rate, breathing, and blood pressure. The basal ganglia are a group of nuclei located deep within the cerebral hemispheres and are involved in a variety of functions including control of voluntary motor movements, procedural learning, habit learning, eye movements, cognition, and emotion.

Criticism[edit | edit source]

The triune brain model, including the concept of the reptilian complex, has been criticized by some neuroscientists. They argue that this model oversimplifies the complexity of the brain and its evolution. Despite this criticism, the model has been influential in popular culture and has been used to explain aspects of human behavior.

See also[edit | edit source]

Reptilian complex Resources
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Contributors: Prab R. Tumpati, MD