Evolution. 1. Collectively, those older parts of the human brain which developed during the amphibian transition from water to land in the Devonian period of the Paleozoic Era. 2. Specifically, those modules of the amphibian midbrain and forebrain which evolved to further life above the waterlines of ancient seas. 3. Those amphibian-inspired paleocircuits a. for hearing and seeing in a higher, drier world, and b. for postural stance in terra firma's gravitational pull.
Usage: Several common gestures and postures (derived, e.g., from the auditory startle and the high-stand display) originated ca. 380 m.y.a. in modules of the amphibian brain. (The latter itself evolved from modules and paleocircuits of the aquatic brain.) Today these play key roles in the expression of dominance and submission.
Media. Sudden movements, looming objects, and bright lights trigger midbrain vision centers which reflexively orient our face and eyes to novel or dangerous stimuli. Meanwhile, midbrain hearing centers stay tuned to abrupt changes in sound. Thus, with its fluctuating cuts in scenery, camera angle, and volume, TV addresses the amphibian brain.
Neuro-notes I: midbrain. As amphibian ancestors emerged from primeval lakes and seas to live part of their lives on land, seeing and hearing sharpened. Two paired centers of the amphibian midbrain--the inferior and superior colliculi--evolved as processing stations for audiovisual cues. The former's hearing centers (the auditory lobes) unconsciously prompt us to crouch from loud noises. The latter's vision centers (the optic lobes) reflexively focus our attention on body motions, gestures, and objects that move.
Neuro-notes II: forebrain. Unlike water's buoyancy, land presents an incredibly heavy environment in which antigravity signs (e.g., the reptilian press-up to a high stand) evolved. The forebrain module in charge of the earliest aggressive "pushup" was a motor area presently called the striatal complex. What remain of its paleocircuits (see BASAL GANGLIA) inspire us to extend our limbs to show dominance as John-Wayne did in the 1960 movie, The Alamo, by similarly "standing tall."
. . . 'She was full of reptiles.' --Joseph Conrad (Lord Jim)
Evolution. 1. Collectively, those early parts of the human brain which developed during the reptilian adaptation to life on land. 2. Of particular interest are modules of the forebrain which evolved to enable reptilian body movements, mating rituals, and signature displays.
Usage I: Many common gestures, postures, and nonverbal routines (expressive, e.g., of dominance, submission, and territoriality) elaborated ca. 280 m.y.a. in modules of the reptilian brain. The latter itself evolved from modules and paleocircuits of the amphibian brain.
Usage II: In the house of the reptile, it makes a difference whether one crouches or stands tall. Flexing the limbs to look small and submissive, or extending them to push-up and seem dominant, is a reptilian ploy used by human beings today. Size displays as encoded, e.g., in boots, business suits, and hands-on-hips postures, have deep, neural roots in the reptilian forebrain, specifically, in rounded masses of grey matter called basal ganglia.
Literature: "Of these the vigilance I dread, and to elude, thus wrapt in mist of midnight vapor, glide obscure, and pry in every bush and brake, where hap may find the serpent sleeping, in whose mazy folds to hide me, and the dark intent I bring." --John Milton (Paradise Lost, Book IX; 1667)
Reptilian ritual. In Nonverbal World, the meaning of persistence (e.g., repeated attempts to dominate) and repetition (e.g., of aggressive head-nods or shakes of a fist) are found in underlying, reptilian-inspired rituals controlled by the habit-prone basal ganglia (a motor control area identified as the protoreptilian brain or R-complex by Paul D. MacLean ).
Reptilian routine. According to MacLean (1990), our nonverbal ruts start in the R-complex, which accounts for many unquestioned, ritualistic, and recurring patterns in our daily master routine. Like a fence lizard's day--which starts with a cautious commute from its rock shelter, and ends with a bask in the sun--our workday unfolds in a series of repetitive, nonverbal acts. Countless office rituals (from morning's coffee huddle, e.g., to the sacred lunch break) are performed in a set manner throughout the working days of our lives.
Prehistory. As reptiles adapted entirely to life on land, terrestrial legs grew longer and stronger than those of aquatic-buoyed amphibian ancestors. In the reptilian spinal cord and brain stem, antigravity reflexes worked to straighten limbs through extensor muscle contractions which lifted the body higher off the ground. Advances in the forebrain's basal ganglia enabled reptiles to walk more confidently than amphibians--and to raise and lower their bodies and broadsides in status displays. The reptile's high-stand display, e.g., presages our own pronated palm-down cues of emphasis while speaking.
Neuro-notes I. 1. The protoreptilian brain, as defined by MacLean, consists of systems a. in the upper spinal cord, b. in the midbrain, and c. in the forebrain's diencephalon and basal ganglia (Isaacson 1974). 2. "The major counterpart of the reptilian forebrain in mammals includes the corpus striatum (caudate plus putamen), globus pallidus, and peripallidal structures [including the substantia innominata, basal nucleus of Meynert, nucleus of the ansa peduncularis, and entopeduncular nucleus]" (MacLean 1975:75).
Neuro-notes II. 1. As a footnote, the relatively high nonverbal IQ of the reptilian basal ganglia was recruited for the development of intelligence in birds, specifically, in the hyperstriatum and neostriatum (rather than, as with mammals, in the cerebral cortex). 2. "Within the avian telencephalon, the dorsal ventricular ridge (DVR) contains higher order and multimodal integration areas. Using multiple regressions on 17 avian taxa, we show that an operational estimate of behavioral flexibility, the frequency of feeding innovation reports in ornithology journals, is most closely predicted by relative size of one of these DVR areas, the hyperstriatum ventrale (Timmermansa et al. 2000:196).
Evolution. 1. Any of several parts of the human brain to emerge during the mammalian adaptation a. to nocturnal (i.e., night) life, and b. to competition with reptilian foes. 2. Specifically, those forebrain areas at the heart of the limbic system which generate emotions for parental care, playfulness, and vocal calling (MacLean 1990).
Usage I: By ca. 150 m.y.a., our mammalian forbears had entrusted their evolutionary future to a new and powerful form of arousal: emotion. In significant measure, the nerve network for emotions, feelings, and moods evolved from neural structures earlier committed to smell.
Usage II: That emotions are like aromas--pleasant or unpleasant--is because they were designed from an olfactory model. Nonverbally, this shows, e.g., in the curled-upper-lip display, which reveals a. nausea, should we smell a fowl odor, and b. disgust, as we listen to a colleague's "rotten" idea. When something looks, sounds, or smells "fishy," the muscles of our face telegraph the reaction for all to see.
Usage III: The fourth great epoch of nonverbal communication took place during the evolution of the mammalian brain. In earlier brains, body movements appeared as reflexes. Neither learning nor memory was required, e.g., to crouch from a looming object, startle to a sound, or withdraw from a painful bite.
Embryology. The mammalian brain is visible by the end of the 5th week of life, as nerve cells project fibers from early nasal tissue to the front end of the rapidly growing cerebral hemispheres (i.e., the telencephalon). By week 6, olfactory bulbs begin to form, which eventually connect to an interpretive center for smell in the neocortex (in the neopallium or "new cloak") of the temporal lobe. The olfactory "smell brain" (i.e., the paleopallium or "old cloak") has important links to the limbic system.
RESEARCH REPORTS: In proportion to brain size, humans have the largest limbic system of any vertebrate, making them the most emotional animals yet to walk the earth. 1. The earliest mammals ". . . were 'reptiles' that were active at night" (Jerison 1976:11). 2. "The evolution of hearing and smell to supplement vision as a distance sense is sufficient reason for the evolution of an enlarged brain in the earliest mammals" (Jerison 1976:11-12). 3. "Progressive evolution of encephalization within the mammals came late in their history, in the last 50 million years of a time span of about 200 million years" (Jerison 1976:7).
Consciousness. Consciousness first appeared in vertebrates ca. 200 m.y.a., in mammals, according to neurophysiologist John Eccles of the Max Planck Institute for Brain Research in Frankfurt (Bower 1992:234). To seek primordial self-awareness, we go to great lengths to quiet the verbal dialogue, e.g., through meditation, chanting, or staring into a candle flame, in order to re-enter the original consciousness which lies beneath the chatty stream in a region of the brain stem known as the thalamus. We experience a deeper-level, mammalian form of consciousness in the evolutionary older thalamus, which is the central processing station for all the senses (except smell) on their routes to the cerebral cortex. It is within the thalamus that a human's central nervous system first experiences consciousness of incoming sensations, before they are re-examined upstream in the neocortex.
Neuro-notes I. 1. "The paleomammalian brain is represented by the limbic system . . ." (MacLean 1975:75). 2. "The neomammalian brain is represented by the rapidly evolving neocortex and structures of the brainstem with which it is primarily connected" (MacLean 1975:75).
Neuro-notes II. "In primitive brains, subcortical and extrathalamic sensory structures were crucial to sensory processing. Comparable structures continue to be important in the advanced brains of modern mammals [such as, e.g., the hindbrain's reticular formation and the midbrain's superior and inferior colliculi], even though the role of the cerebral cortex and thalamus in sensory processing has expanded enormously" (Willis 1998C:109). Studies in cats, e.g., show the superior colliculi to be especially important for perceiving objects in space; the acuity of "collicular vision" in humans is unknown (Willis 1998D; but see NONVERBAL CONSCIOUSNESS, Blindsight).
Evolution. 1. Collectively, those specialized areas of the human brain which evolved during the primate adaptation a. to diurnal (i.e., daylight) living, and b. to a life in trees. 2. Specifically, those modules of the forebrain which process color, eye-hand coordination, facial recognition, grasping, and 3D navigation by sight.
Hand signals I. With agile digits designed for climbing, our primate ancestors extended their forelimbs to reach for and to grasp insects, fruits, and berries. Manual dexterity (through advances in motor, premotor, supplementary, and association areas of the neocortex) led to the use of leaves, sticks, bones, and stones as tools (see ARTIFACT). (N.B.: These modular areas of neocortex managed the hand-and-arm movements our species turned a. to the manufacture of chipped-stone hand-axes, and b. to the use of conceptual hand-signals called mime cues.)
Hand signals II. The primate brain enabled voluntary movements of the hands and arms, to achieve goals beyond locomotion (see WALKING) and standing on all fours. Sophisticated motor-control centers permitted new movements, such as reaching, grasping, and grooming with the fingertips (which also could be used as gestures, i.e., as body movements to convey information about intentions and moods).
Eye signs. By ca. 35-to-40 m.y.a. in the earliest apes, the primate brain dedicated distinct modules of visual cortex a. to the precise coordination of hand-and-eye movements, and b. to the recognition of faces. (In the living apes, dedicated nerve cells of the lower temporal lobe respond to hands and faces exclusively [see, e.g., Kandel et al. 1991:458-59].) "Marler  and Van Hoof  agreed that in most species of primates the face . . . is the most important part of the animal" [Izard 1971:38]).
Climbing cues. Visual learning is the hallmark of the primate brain. Foraging in trees (and using sight rather than scent) to find colorful fruits and berries went hand-in-hand with remembering where and what to pick. Unlike birds which fly directly to food spotted in trees, primates must chart a clever route through labyrinthine vines, limbs, and leaves. Mentally, they must navigate from point A to point B by decoding the branchways from many angles. (N.B.: In their 3D world, primates became skilled arboreal navigators. Today's monkeys, e.g., have sharp color vision, depth perception, and enhanced memory to recall the location of edibles scattered among forking branches and twisting vines.)
RESEARCH REPORTS: 1. "Over half of the neocortex in [living] nonhuman primates is occupied by visual areas ['At least 25 visual areas beyond the primary visual cortex . . . ']" (Sereno et al. 1995:889). 2. The primate's inferotemporal cortex is thought to be essential for object recognition (Wang et al. 1996:1665).
Neuro-notes I. Primates have prehensile hands with which to grab tree branches, fruits, and insects. Deliberate grasping is mediated by a region of the frontal neocortex called the supplementary motor area. This module programs complex muscle contractions to open and close the hand on purpose. The supplementary area also helps coordinate arm postures required to support the hand movement itself. At the same time, the primary motor cortex regulates the force with which moves are exerted. Instructions from these areas descend through the corticospinal tract directly to spinal-cord circuits below, which instruct muscles in the forearm to open and close the hand (deliberately: see Neuro-notes IV).
Neuro-notes II. The primate brain's premotor cortex controls the proximal movements which project an arm to its target. The premotor cortex, which receives visual input from the posterior parietal cortex, sends fibers to the brain stem's medial descending systems, as well, notably, to the (not-so-deliberate, i.e., reflexive) reticulospinal tract, which links to spinal circuits which control our proximal and axial muscles.
Neuro-notes III. The decision to grasp comes from a variety of areas in the primate brain. Sensory circuits, e.g., may advise a slipping hand to tighten around a branch. The basal ganglia may influence hand-over-hand movements of the climbing sequence itself. The limbic system may excitedly close a hand over a plump red berry. In such cases, the decision routes through reflexive circuits standing by in the brain stem: these instruct the spinal cord to close the hand.
Neuro-notes IV. A novel feature of the primate brain is its ability to grasp deliberately--i.e., to grasp on purpose--through the corticospinal tract (thus bypassing older brain-stem circuits altogether). This more advanced nerve tract, which began its evolution in the mammalian brain, elaborated in the primate brain. (N.B.: The corticospinal tract adds precision and voluntary control to our grasping gestures.)
Neuro-notes V. A region of the primate brain's posterior parietal cortex (Brodmann's area 5) processes information received from the primary sensory cortex (Brodmann's areas 1, 2, and 3), relating it to the position of the reaching arm. (N.B.: Special arm projection neurons fire when a monkey reaches for a nearby food item, e.g., but not if the arm reaches out merely for the sake of reaching.)
Neuro-notes VI. Area 5 receives input from the inner ear's vestibular sense, as well, regarding the head's orientation in space. It also hears from premotor areas of the frontal neocortex, which govern the motor plans for reaching, and from the mammalian brain's limbic system (the latter's cingulate gyrus, e.g., keeps area 5 updated on the primate's emotional state of mind).
Neuro-notes VII. ". . . using a dedicated monkey PET scanner at Hamamatsu Photonics in Hamakita, Japan, Hirotaka Onoe's team at the Tokyo Metropolitan Institute for Neuroscience last year discovered a new site of color processing in the monkey visual system" (Barinaga 1998:1397).
Neuro-notes VIII. 1. Studies show that the cerebellum of apes and human beings is proportionately larger than that of monkeys, perhaps due to adaptations, in the former primates, for bipedal walking and brachiation, as well as for monkey-like climbing (Rillinga and Inselb 1998). 2. "Hence it is interesting that a species with one of the largest positive cerebellar residuals in our study (Hylobates lar) is among the most versatile, with climbing, bipedal walking and running, leaping, bridging, and brachiating all in its repertoire (Hollihn, 1984). The cerebellum has also been implicated in motor planning (Ghez, 1991). In contrast to humans and chimpanzees, baboons apparently lack 'presyntactical motor planning', the ability to modify current movements based on awareness of movements to follow (Ott et al., 1994). Thus, the larger relative cerebellar volume of apes compared with monkeys might reflect an increased cognitive representation in the cerebellum of hominoids" (Rillinga and Inselb 1998).
Give thy thoughts no tongue . . . . --Shakespeare (Hamlet, I, 3)
Evolution. 1. Collectively, those modules, centers, and circuits of the brain which developed ca. 4 million-to-200,000 years ago in members of the genus, Homo. 2. Specifically, those areas of the primate forebrain, midbrain, and hindbrain adapted for a. emotional communication, b. linguistic communication, c. sequential planning, d. tool-making, and e. rational thought.
Usage I: The human brain is both verbal (see SPEECH and WORD) and nonverbal. Sometime between ca. 4 million and 200,000 years ago (anthropologists are not sure when) human beings began to speak. And yet, despite the immense power of words, nonverbal signals are still used a. to convey emotions, feelings, and moods; and b. to express the highs and lows of social status. Moreover, vocalizing itself--perhaps because speech and manual signing co-evolved--is accompanied in every culture by a panoply of palm-up, palm-down, pointing, and mime cues. (N.B.: Mime cues pantomime shapes, relationships, and concepts, unexpressed before Homo set foot in Nonverbal World.)
Usage II: Incredibly little is new in the human brain that cannot be found (on a simpler scale) in the aquatic, amphibian, reptilian, mammalian, and primate brains preceding it. Yet, from a nonverbal perspective (i.e., one focusing on communication), what sets our brain apart are those highly specialized areas which control fine motor movements of the fingers, lips, and tongue, all of which evolved as neurological "smart parts."
Intellectual digits. Areas of neocortex empowered members of the genus Homo to move their fingers through complex sequences of steps resulting in the manufacture, e.g., of Oldowan stone tools (see ARTIFACT). Following up perhaps 200,000 years ago, early members of Homo sapiens moved their fingers, lips, and tongues in a parallel, sequenced manner to communicate about the manufacture of tools and artifacts. By mirroring the process, i.e., by pantomiming it through patterns of articulation (manual as well as vocal), language was born.
Mental imagery. The brain creates its own nonverbal imagery (i.e., "sees" without external visual input, through the "mind's eye") by activating ". . . the dorsal (area 19) and ventral (fusiform gyrus) visual association areas, superior and inferior parietal cortex, as well as other nonvisual cortices such as the dorsolateral prefrontal cortex and angular gyrus" (Miyashita 1995:1719).
Right brain, left brain I. Studies agree that as nonverbal cues are sent and received, they are more strongly influenced by modules of the right-side neocortex (esp. in right-handed individuals) than they are by left-sided modules. Anatomically, this is reflected a. in the greater volume of white matter (i.e., of myelinated axons which link nerve-cell bodies) in the right neocortical hemisphere, and b. in the greater volume of gray matter (i.e., of nerve cell bodies or neurons) in the left. The right brain's superior fiber linkages enable its neurons to better communicate with feelings, memories, and senses, thus giving this side its deeper-reaching holistic, nonverbal, and "big picture" skills. The left brain's superior neuronal volume, meanwhile, allows for better communication among the neocortical neurons themselves, which gives this side a greater analytic and intellectually narrower "focus" (see, e.g., Gur et al. 1980). Research by UCLA neuroscientist, Daniel Geschwind and colleagues shows that left-handers have more symmetric brains, due to genetic control; the sides are more equal than those in brains of right-handers (March 11, 2002 article in Proceedings of the National Academy of Sciences).
Right brain, left brain II. Communication problems due to deficits in the usually dominant left-brain hemisphere include Broca's aphasia and ideomotor apraxia. Problems in the usually nondominant right-brain include aprosody, inattention to one side of the body (hemi-inattention), visuospatial disorders, and affective agnosia. The dominant hemisphere produces, processes, and stores individual speech sounds. The nondominant hemisphere produces and processes the intonation and melody patterns of speech (i.e., prosody; see TONE OF VOICE).
Right brain, left brain III. To assist in the production and understanding of nonverbal cues, fiberlinks of white matter connect modules of neocortex within the right-brain hemisphere. Preadapted white-matter fibers link modules within the left-brain hemisphere, as well, to assist in the production and understanding of speech. 1. Axon cables make up short, U-shaped association tracts which link adjacent neocortical gyri. 2. Longer, thicker association-tract cables link more distant modules and lobes within each hemisphere. Linguistically, the key cable is the superior longitudinal fasciculus. It links the temporal lobe's area 22 and the frontal lobe's area triangularis to the angular gyrus and the supramarginal gyrus of the parietal lobe. The best known part of this important communications cable is the left-brain's arcuate fasciculus (see VERBAL CENTER).
Supplementary motor cortex (SMC). 1. "Stimulation of the supplementary motor cortex can produce vocalization or complex postural movements, such as a slow movement of the contralateral hand in an outward, backward, and upward direction. This hand movement is accompanied by a movement of the head and eyes toward the hand" (Willis 1998:215). 2. Imaging studies reveal that merely thinking about a body movement activates the supplementary motor cortex; the subsequent movement itself activates both the latter area and the primary motor cortex (Willis 1998:216). [Author's note: We hypothesize that PET studies of linguistic tasks showing SMC activity that is unrelated to speech may reveal gestural fossils ("ghosts") of movements humans once used to communicate apart from (i.e., before the advent of) words themselves.]
Neuro-notes I. The jump from posture, facial expression, and gesture to sign language and speech was a quantum leap in evolution. And yet, the necessary brain areas (as well as the necessary body movements) were established hundreds of millions of years before our kind arrived in Nonverbal World.
Neuro-notes II. To the primate brain's hand-and-arm gestures, our brain added precision to fingertips by attaching nerve fibers from the primary motor neocortex directly to spinal motor neurons in charge of single muscle fibers within each digit. Direct connections were made through the descending corticospinal tract to control these more precise movements of the hand and fingers.
Neuro-notes III. With practice we can thread a needle, while our closest animal relative, the chimpanzee, cannot. No amount of practice or reward has yet trained a chimp to succeed in advanced tasks of such precision; the primate brain simply lacks the necessary control.
Neuro-notes IV. As our digits became more precise, so did our lips and tongue. These body parts, too, occupy more than their share of space on the primary motor map (see HOMUNCULUS).
Neuro-notes V. Using the mammalian tongue's food-tossing ability as a start, our human brain added precision to the tongue tip just as it did to the fingertips. Nerve fibers from the primary motor cortex were linked directly to motor neurons of the hypoglossal nerve (cranial XII) in charge of contracting individual muscle fibers within the tongue. Direct connections were made through the descending corticobulbar tract to precisely control movements of the tongue tip needed for speech.
Neuro-notes VI. Humans are what they are today because their ancestors followed a knowledge path. At every branch in the 500-million-year-old tree of vertebrate evolution, the precursors of humanity opted for brains over brawn, speed, size, or any lesser adaptation. Whenever the option of intelligent response or pre-programmed reaction presented itself, a single choice was made: Be smart.