The Collaborative International Dictionary
limbic system \limbic system\ n. (Anatomy, Neurophysiology) A group of neural structures in the brain below the cerebral cortex, centered on the hypothalamus and including the hippocampus and amygdala, involved with control of emotion, motivation, memory, and some homeostatic regulatory processes.
At the most ancient part of the human brain lies the
spinal cord; the medulla and pons, which comprise the
hindbrain; and the midbrain. This cobination of spinal
cord, hindbrain, and midbrain MacLean calls the neural
chassis. It contains the basic neural machinery for
reproduction and self-preservation, . . . MacLean has
distinguished three sorts of [more recent brain
structures controlling] the neural chassis. The most
ancient of them surround the midbrain. . . . We share
it with the other mammals and the reptiles. It probably
evolved several hundred million years ago. MacLean
calls it the reptilian or R-complex. Surrounding the
R-complex is the limbic system, so called because it
borders on the underlying brain. (Our arms and legs are
called limbs because they are peripheral to the rest of
the body.) We share the limbic system with other
mammals, but not, in its full elaboration, with the
reptiles. It probably evolved more than one hundred
fifty million years ago. Finally, surrounding the rest
of the brain and clearly the most recent evolutionary
accretion, is the neocortex.
--Carl Sagan
(The Dragons
of Eden, New
York, Random
House, 1977).
Wiktionary
n. (context anatomy English) Part of the human brain involved in emotion, motivation, and emotional association with memory; includes amygdala, cingulate gyrus, fornicate gyrus, hippocampus, hypothalamus, mammillary body, nucleus accumbens, orbitofrontal cortex and parahippocampal gyrus.
WordNet
n. a system of functionally related neural structures in the brain that are involved in emotional behavior [syn: visceral brain, limbic brain]
Wikipedia
The limbic system is a set of brain structures located on both sides of the thalamus, immediately underneath the cerebrum. It is also commonly referred to as the paleomammalian brain although this term "is no longer espoused by the majority of comparative neuroscientists in the post-2000 era." It is not a separate system but a collection of structures from the telencephalon, diencephalon, and mesencephalon. It includes the olfactory bulbs, hippocampus, hypothalamus, amygdala, anterior thalamic nuclei, fornix, columns of fornix, mammillary body, septum pellucidum, habenular commissure, cingulate gyrus, parahippocampal gyrus, limbic cortex, and limbic midbrain areas.
The limbic system supports a variety of functions including emotion, behavior, motivation, long-term memory, and olfaction. Emotional life is largely housed in the limbic system, and it has a great deal to do with the formation of memories.
Although the term only originated in the 1940s, some neuroscientists, including Joseph LeDoux, have suggested that the concept of a functionally unified limbic system should be abandoned as obsolete because it is grounded mainly in historical concepts of brain anatomy that are no longer accepted as accurate.
Usage examples of "limbic system".
Classical conditioning- the ability of Pavlov's dogs to salivate when the bells rang-seems to be located in the limbic system.
Surely the limbic system and the emotional charge of every incident must be crucially involved in the entrainment or encoding or embedding of a memory.
Likewise, animal holons that lack the exterior form known as the limbic system will probably also lack an interior that contains differentiated emotions, and so on.
Two hands, two small human hands, working the twin decks, the triple decks, the quadruple decks of the Limbic System house.
That is why the brainstem is surrounded by the R-complex, then the limbic system and finally the cerebral cortex.
They started with neurons in the limbic system, the prefrontal cortex, and the amygdala.
For this reason, the visceral brain is sometimes called the limbic system.
Rivers and Borrow taught that neurophysiological processes in the mind-body, such as dreaming, promoted the integration of limbic system dramas, thus increasing awareness and encouraging cognitive and emotive areas to merge.