Men ought to know that from the brain, and from the brain only, arise our pleasures, joys, laughter and jests, as well as our sorrows, pains, griefs and tears. --Hippocrates (5th Century, B.C.; quoted in Kandel et al. 1991:iv)
Neuro term. 1. Those circuits, centers, and modules of the central nervous system which are involved in sending, receiving, and processing speechless signs. 2. In right-handed individuals, modules of the right brain cerebral hemisphere, considered to be morenonverbal, holistic, visuospatial, and intuitive than the verbal, analytic, sequential, and rational left brain hemisphere (see HUMAN BRAIN, Right brain, left brain). 3. Those ancient centers (e.g., nuclei) and paleocircuits of the nervous system which evolved in vertebrates--from the jawless fishes to human ancestors (e.g., Homo habilis)--for communication before the advent of speech.
Usage: Just as the brain's newer speech centers (e.g., Broca's area) control language communication, earlier areas of the nonverbal brain control communication apart from words. Knowing its parts and wiring helps us decode nonverbal messages.
Media. "A skillful outline can be more appealing than a photographic image. The simple line appeals to the brain which has limited attention and limited abilities to process information rapidly." (San Diego Union-Tribune interview with UC-San Diego neuroscientist, Vilayanur Ramachandran [May 7, 1999, A1, A-19])
(3) REPTILIAN BRAIN: With reptiles, 1. the vestibuloreticulospinal system evolved to control axial and girdle muscles for posture relative to positions of the head. 2. The basal ganglia-ansa lenticularis pathway reverberated links between the amygdala and basal ganglia via the ansa lenticularis and lenticulate fasciculus to the midbrain tegmentum, red nucleus, and reticular system to spinal cord interneurons required for the high-stand display.
(4) MAMMALIAN BRAIN: With mammals, 1. the amygdalo-hypothalamic tract became more elaborate: the central amygdala's link to the hypothalamus, via the stria terminalis, provided wiring for defensive postures (see, e.g., BROADSIDE DISPLAY). 2. Hypothalamus-spinal cord pathways adapted as well: the hypothalamus's dorsomedial and ventromedial nuclei fed a. indirectly via the brain stem's reticular system, and b. directly through fiberlinks to lower brain-stem and spinal-cord circuits to cord motor neurons for emotion cues (see, e.g., ANGER). 3. The septo-hypothalamo-midbrain continuum evolved: the medial forebrain bundle (from the olfactory forebrain and limbic system's septal nuclei) via the hypothalamus's lateral nuclei to midbrain-tegmentum brain-stem motor centers, mediated emotions (see, e.g., FEAR). 4. The cingulate gyrus facial circuit evolved: links run from the anterior cingulate cortex a. to the hippocampus, b. to the amygdala, c. to the hypothalamus, and d. through the brain stem, finally e. to the vagus (cranial X) and facial (cranial VII) nerves which, respectively, control the larynx and facial muscles required for vocalizing and moving the lips.