See also Amphibian Brain

Copyright © 1998 - 2001 (David B. Givens/Center for Nonverbal Studies) Illustration detail from Getting There (copyright 1993 by William Howells)

hypo

HYPOTHALAMUS

Brain. 1. A subcortical group of nuclei in the forebrain which serves a. the limbic system, b. the autonomic nervous system (see FIGHT-OR-FLIGHT), and c. the endocrine system. 2. A thumbnail-sized neuro structure which organizes basic nonverbal responses, such as aggression, anger, sexuality, and fear.

Usage: Giving input to--and receiving output from--the limbic system, the hypothalamus mediates diverse nonverbal signs associated with emotion.

Evolution I. The hypothalamus has deep evolutionary roots in the chemical sense of smell (see AROMA CUE).

Evolution II. As the forebrain's main chemical-control area, the hypothalamus regulates piscine adrenal medullae, chemical-releasing glands which, in living fish, consist of two lines of cells near the kidneys. The adrenal medullae pump adrenaline into the bloodstream, from where it effects every cell in the fish's body. (N.B.: In humans, adrenaline speeds up body movements, strengthens muscle contractions, and energizes the activity of spinal-cord paleocircuits.)

RESEARCH REPORTS: 1. Pathways involved in oral and genital functions "converge in that part of the hypothalamus in which electrical stimulation results in angry and defensive behaviour" (MacLean 1973:44). 2. In higher vertebrates, the olfactory system and the hypophysis [i.e., the pituitary gland (which is linked to the hypothalamus)] "are derived from a single patch of embryonic [neuroectoderm" (Stoddart 1990:13). 3. The hypothalamus mediates many nonverbal behaviors through reticular nuclei in the brain stem (Guyton 1996).

Neuro-notes. Regarding hypothalamic nuclei and nonverbal signs, a. the dorsomedial nucleus stimulates savage behavior; b. the posterior nucleus stimulates the sympathetic nervous system; c. the preoptic area houses the sexual dimorphic nucleus; and d. the anterior nucleus stimulates the parasympathetic nervous system (Fix 1995; see REST-AND-DIGEST).

Copyright © 1998 - 2001 (David B. Givens/Center for Nonverbal Studies) Detail of illustration from Mapping the Mind (copyright Weidenfeld & Nicolson 1998)

REST-AND-DIGEST

Other men live to eat, while I eat to live. --Socrates

Relaxation response. 1. A pleasant feeling of calmness and well-being experienced as a. heart rate slows, b. smooth muscles contract, and c. glands secrete while the body digests food. 2. Physiologically, a rudimentary model for the sensation of happiness.

Usage: Many involuntary nonverbal signs (e.g., contracted pupils, moistened eyes (i.e., glistening, brought on by stimulation of the lacrimal glands), slowed breathing rate, and mouth-watering (due to watery secretions of the salivary glands [accompanied by increased swallowing])--along with signs of relaxation (e.g., warm, dry palms; lean-forward; lean-back) and satiation (e.g., supinated fists) are visible in the visceral feelings and involuntary movements of our rest-and-digest response.

U.S. politics. "He [Frank Meeks, owner of 59 Domino's pizza franchises in the Washington, D.C. area] recalls that Nov. 17, 1995, during the government shutdown, was 'pizza night' for Monica L. Lewinsky and President Bill Clinton, according to Lewinsky's day book" (Schafer 1998:A5; see BIG MAC).

Observations. 1. Rest-and-digest-related cues (such positive signals as body alignment, eye contact, vocal satisfaction [e.g., "hmm," "ooh," and "um"], head-nods, and smiling) are often visible in luncheon meetings around a conference table. 2. In courtship, couples eat together to relax, to relate, and to respond in the rest-and-digest mode to offset feelings of stranger anxiety. (N.B.: Genital swelling is a rest-and-digest [i.e., a parasympathetic, response; see LOVE SIGNALS V].) 3. In a restaurant, rest-and-digest paleocircuits contract the urinary bladder, thus prompting visits to the restroom.

Evolution. Rest-and-digest is an ancient parasympathetic response pattern which, in the aquatic brain, slowed heart beat rate (and ventricular force) to conserve bodily energy, e.g., to prepare a fish to digest its meal.

Neuro-notes. 1. The hypothalamus controls our rest-and-digest response. 2. "The actions of the sympathetic and parasympathetic divisions are mediated by different neurotransmitters and are largely antagonic, e.g., where one promotes contraction of smooth muscle, the other promotes dilation" (Damasio 1994:206).

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