DECEMBER 20, 2021: THIS PAGE NOW CONTAINS OUR EVOLVING BOOK DRAFT ON THE NONVERBAL ORIGIN OF LANGUAGE. (To see the entry for ADAM'S-APPLE-JUMP, please click HERE.)
David Givens's article on "Nonverbal Steps to the Origin of Language" is published in Sternberg, Robert J. and Aleksandra Kostic (Eds.) (2020). Social Intelligence: The Adaptive Advantages of Nonverbal Communication (London, Palgrave-Macmillan, pp. 163-189).
This book synthesizes available communication research and proposes 15 nonverbal steps leading to the origin of gestural and vocal language in genus Homo. Each step worked its way into tissues of the human nervous system. In combination and in synergy, the steps enabled modern linguistic communication in Homo sapiens. The neuromuscular changes occasioned in each step--and their roles in gestured and spoken language--are outlined and explored.
Keywords
Bioneurology; Gesture; Language origins; Nonverbal communication
Highlights
* Speech and gesture are rooted in a shared caudal-hindbrain, upper-spinal-cord compartment.
* Intra-species communication serves a reproductive function, later co-opted by language.
* Nonverbal messaging set standards for later speech and gesture.
* Language builds upon early, preexisting systems of vertebrate communication.
* Language reflects the earlier systems' roles in self-assertion, species recognition, genetic reproduction, emotional expression, and attention to objects.
Nonverbal Steps to the Origin of Language
Introduction: The Nonverbal-Verbal Nexus
In the following 15 chapters, the authors outline fifteen nonverbal steps precursing and leading to the origin of manually signed and spoken verbal language. Human language did not arise spontaneously on its own, but rather was superimposed upon a set of preexisting structural and semantic features of nonverbal communication.
Indeed, the book approaches the origin of language from the seemingly paradoxical perspective of nonverbal communication. Nonverbal messaging preceded linguistic expression by three billion years. The former not only came before, but also established the patterns and standards of linguistic communication through gesture and by word of mouth. It is proposed below that human language--in both its vocal and gestural forms--was superimposed upon the older nonverbal medium of expression (to explore the latter form of communication, see Givens 2015). Today’s verbal communication reflects the earlier medium’s role in (1) self-assertion, (2) species recognition, (3) genetic reproduction, (4) emotional expression, and (5) attention to objects.
Medium of the molecule. Nonverbal communication originated some 3.5 [Sept. 2016: newly found fossils from Greenland are now dated to 3.7] billion years ago in unicellular organisms known as cyanobacteria (blue-green algae), early life forms that inhabited shallow-water communities called stromatolites. Voiceless, eyeless, unable to touch or hear, earth’s first residents communicated chemically through the medium of the molecule.
Chemical cues represent the first of 15 communicative steps that led to the origin of manually signed and spoken language in genus Homo. This article synthesizes research and outlines each of the adaptive stages that led to language--from the chemical messages of cyanobacteria to the sonorous vocalizations of human speech today.
Step 1 (3.7 billion years ago): Chemical Messages--“I am Here”
Summary. Before neurons or brains existed, it was established that organisms should communicate through messaging molecules about matters of reproductive function. Known as oligopeptides, such molecules were used for intercellular quorum sensing. In living bacteria (e.g., Escherichia coli), Niu and colleagues characterize quorum sensing as a form of sophisticated linguistic-like communication involved in bacterial reproduction (Niu et al. 2013). Today the oligopeptide neurotensin is found in human-brain circuits, including those of prefrontal cortex, Broca’s area, and parts of the limbic system (St-Gelais et al. 2006). The fundamental meaning of early chemical messages was about physical presence: “I am here.”
I am here. From the beginning of life, intra-species communication has served a reproductive function. In cyanobacteria, individual organisms emitted chemical signals to announce physical presence--saying, essentially, “I am here”--to fellow bacteria in the community. Emitted messaging molecules (e.g., acyl-homoserine lactones) were not addressed to any one bacterium in particular, but rather to bacteria in the stromatolite as a whole. Nor did individual bacteria respond back directly to any one sender. Instead, the entire group responded collectively to the census-like messages about population density through quorum sensing. Based on the overall volume of chemical “I am here” signals received, the stromatolite community--as an aggregate--enacted changes to its reproductive growth (Freestone 2013) and gene expression (Miller & Bassler 2001).
In cyanobacteria and other organisms, “I am here” messages are in keeping with the basic biology of species recognition. Recognition of one’s own species members serves a reproductive function, in that conspecifics must somehow recognize one another as potential reproductive partners (Ridley 2004).
Regarding human language, “I am here” is implicit today in every signed movement and spoken word. The linguistic sign--whether visible or auditory--is a token of physical presence. Established in early life forms, this most basic of self assertions may be considered a necessary, but not a sufficient, first step toward linguistic communication in Homo.
Step 2 (500 million years ago): Vertebrate Messages--“I am Here” (Advent of “I/Me”)
Summary. In chordates, circuits for vocal-laryngeal and pectoral-movement communication link in a caudal hindbrain, rh8-upper-spinal-cord compartment (Bass & Chagnaud 2013). The neurological linkage explains why hand gestures and vocalizations are intimately coupled in the evolution of tool making and speech. Among the earliest audiovisual messages was the aforementioned assertion of “I/me,” viz., that “I am here.”
Retaining chemical messages through scent glands, vertebrates added audiovisual signals to further announce physical presence. It was established early on in chordates that respiratory vocalization and forelimb movements should be key players in audiovisual communication. Beginning 500 million years ago, circuits for vocal and movement communication were linked in a specific compartment of the chordate nervous system. Then, as today, this compartmental linkage explains why vertebrates—from fish to reptiles to human beings—call attention to themselves through respiratory sounds (e.g., vocalizations) and pectoral-area limb movements (e.g., gestures).
From the gorilla’s (Gorilla gorilla) chest-beating, the catfish’s (Synodontis schoutedeni) pectoral-fin squeaks, the humpback whale’s (Megaptera novaeangliae) pectoral flipper-slaps, and the human being’s (Homo sapiens) hand-waving, all such signals are pectoral cues tendered to announce physical presence. All may be accompanied, variously, by laryngeal vocalizations, vocal roars, drumming sounds (produced by swim bladders), and “singing” (emitted from a whale’s respiratory system). All are messages designed to announce the fact of “me”—to say, “I am here.”
The word “I” is included in Swadesh’s (1971) intuited list of 100 universal vocabulary items. “I” words tend to be phonetically simple and monosyllabic, a testimony, perhaps, to their elementary origin. In African languages, for example, “I/me” is expressed variously by “me” (!Kung “mi”), “nee” (Hausa “ni”), and “tee” (Hottentot “ti”; Ruhlen 1994, p. 35). (Items in quotes are English pronunciations; items in parentheses are phonetic transcriptions.) In Native American languages, “I/my” is expressed variously by “no” (Resigaro “no”), “see” (Carrier “si”), and “neen” (Micmac “nin”; Ruhlen 1994, p. 52).
Like a cyanobacterium’s chemical expression of “me,” audiovisual advertisements-of-self subserve a reproductive function. In human courtship, “I am here” messages are a part of courting’s Attention Phase, the first of four stages in a progression leading to sexual contact (Givens 1978, 2005). Before speaking, unacquainted couples may call attention to themselves through attractive clothing and with smiles, conspicuous gestures, and loud laughter. In the first stage of courtship “I am here” is often expressed nonverbally and apart from words.
Regarding linguistic communication, audiovisual “I am here” messages are implicit today in both signed and spoken words. Such messages may be considered a necessary, but not a sufficient, second step toward language in Homo.
Step 3 (500 million years ago): Vertebrate Messages--“You are There” (Advent of “You”)
Summary. In service to species recognition and reproductive function, sensorimotor systems of the vertebrate brain respond to “I/me” assertions with messages recognizing “you,” viz., that “you are there.” Ancient “you” messages built a foundation for the back-and-forth, dialogic pattern of speech.
You. Coincidental with Step 2, vertebrate audiovisual communication added a two-way, interpersonal dimension to the one-way chemical signals of cyanobacteria. Vertebrate message receivers could recognize and respond in kind to a sender’s nonverbal Attention Phase cues. By responding to an “I am here” message, a recipient implicitly recognizes “you,” the sender, and the fact that “you are there.” Once again, a great deal of this early messaging served a reproductive function in courtship.
In short, my son, note her every action and movement. If you report to me faithfully all these things, I shall be able to make out the hidden secret of her heart and discover how she feels with regard to my love; for I may tell you, Sancho, if you do not know it already, that among lovers exterior signs of this sort are the most reliable couriers that there are, bringing news of what goes on inside the heart. --Miguel de Cervantes, Don Quixote (1605, p. 566)
The second stage in courtship communication has been called the Recognition Phase (Givens 1978, 2005). In this stage couples seek nonverbal responses to signs emitted in the preceding Attention Phase. A man’s initial bid for attention (“I am here") may be followed, for example, by a woman’s direct eye contact, responsive smile, and hair-preening gestures (Scheflen 1965). These and other nonverbal signs reveal a recipient’s unspoken acknowledgement that a sender’s message has been seen or heard. They proclaim, apart from words, that “you are there.” Recognition cues are the afferent (incoming) bodily signals received in response to a sender’s efferent (outgoing) Attention Phase cues.
Like the “I” word, “you” is included in Swadesh’s (1971) list of 100 basic vocabulary items. And indeed, the “you” expression may be a linguistic universal. Like “I,” “you” tends to be phonetically simple and monosyllabic. In African languages, for instance, “you” is expressed variously by “yeen” (Dinka “yin”), “kai” (Hausa “kai”), and “coo” (Mbundu “ku”; Ruhlen 1994, p. 35). In Native American languages, “you” may be expressed as “bee” (Arawak “bi”), “geel” (Micmac “gil”), and “nee” (Navaho “ni”; Ruhlen 1994, p. 52).
Nonhuman courtship proceeds upon wordless “you”-like messages. For example, in the hamlet fish (Hypoplectrus unicolor), a hermaphroditic “male’s” Attention Phase spawning sound--produced by pectoral-girdle muscle contractions and vibrating muscles attached to the swim bladder--may be recognized with fin-spreading and bodily-quivering signs returned by the hermaphroditic “female.” In diverse species of frogs (Rana sp.), a male’s mating call and inflated vocal sacs while calling may be recognized by a female’s submissively lowered-body. In the Puerto Rican dwarf gecko (Sphaerodactylus nicholsi), a male’s head-bob may be met with a female’s forelimb-lift of recognition. In the North American moose (Alces sp.), a male’s grunting call may be returned by a female’s higher-pitched wailing sound.
Ancient “you are there” messages predate linguistic communication and built a foundation for the basic dialogic pattern of language. They begin the back-and-forth, give-and-take dialogue that characterizes today’s sign languages and vocal speech. Nonverbal “you” may thus be considered a necessary, but not a sufficient, step toward language in Homo.
Pronouns
Step 4 (150 million years ago): Mammalian Emotion
Summary. With mammals, emotion becomes a volatile factor in intra- and interspecies communication. Housed in the limbic system, emotions are mammalian elaborations of vertebrate arousal patterns, in which dopamine, noradrenaline, serotonin, and other neurochemicals step-up or step-down the brain's activity level, as visible in body movements, facial expressions, and gestures. Emotional communication was shaped by social factors that reverberated in the cortex’s cingulate gyrus, for grooming with the hands, vocal calling, and maternal care of the young (MacLean 1990).
Affect. Face-to-face conversation is often accompanied by emotions such as happiness, sadness, anger, and uncertainty. These feelings may be telegraphed by nonverbal signs that include smiling, pouting, frowning, and shoulder shrugging. Emotion may also be audible in tone of voice. Spontaneous conversations are rarely dispassionate; more often than not they show affect.
In mammals and primates, affect is displayed by easily read emotion cues such as the cat’s (Felis catus) arched back, the dog’s (Canis familiaris) tail wag, and the chimpanzee’s (Pan troglodytes) fear grin. In humans, linguistic signing and speaking are often accompanied by emotion cues. American Sign Language’s hand signals for “Who?”, “What?” and “Why?”, for example, may be given with a signer’s eyebrows lowered in puzzlement or uncertainty.
Social jeopardy. One may choose to speak or remain silent. According to Goffman (1967), the former choice can involve a feeling of personal risk. Goffman maintains that people place themselves in a state of social uncertainty or ”jeopardy” when they make a verbal statement. There is an element of fear that receivers might react negatively by laughing, scowling, or smirking in disapproval. As Levinas (1989) writes, “By offering a word, the subject putting himself forward lays himself open and, in a sense, prays [for a positive response]” (p. 149).
Morris (1967) adds that talk may be informative (“The milk is in the refrigerator”), exploratory (“Where do you work?”), mood sharing (“I feel bad for him”), or polite (“Nice day”). He calls statements in the latter category “grooming talk,” likening their use to the manual grooming contact of primates. Kringelbach and Berridge (2012) note that social pleasures include “. . . vital sensory features such as visual faces, touch features of grooming and caress, as well as in humans more abstract and cognitive features of social reward and relationship evaluation. These may be especially important triggers for the brain’s hedonic networks in human beings.”
Indeed, there is neurological evidence that talking is intrinsically pleasurable. Talk is most gratifying when subject matter pertains to oneself, as in self-disclosure. As Tamir and Mitchell (2012) learned in fMRI research: “Self-disclosure was strongly associated with increased activation in brain regions that form the mesolimbic dopamine [pleasure-reward] system, including the nucleus accumbens and ventral tegmental area.” Pell and colleagues have found evidence in right cerebral-hemisphere brain modules for decoding emotional sounds--a precursor module for vocal (e.g., giggles, growls, and sobs), and a more recent module for linguistic (words and phrases), prosody (Pell et al. 2015; see “Prosody” below, Step 15). Mammalian emotion represents another necessary, but not sufficient, step toward language in Homo.
Interjections
Step 5 (150 million years ago): Mammalian Acrobatic Tongue
Summary. In mammals, motor areas of cerebral cortex governing tongue movement enlarged to provide greater control in chewing. Mobile mammalian tongues replaced the more rigid tongues of fish, amphibians, and reptiles. In chewing, the trick for a tongue is not to be bitten in the process. The mammalian tongue’s innate dexterity kept it safe from teeth and conferred, as a byproduct, an ability to articulate vowel sounds and consonants.
Food tossing. Before saying words the mammalian tongue had been a humble manager of "food tossing." Through acrobatic maneuvers, chewed morsels were distributed by tongue movements to premolars and molars for finer grinding and pulping.
Before mammals, tongue movements were limited to backward and forward. The mechanical function was to move food in the throat back toward the gullet. In mammals, working through the hypoglossal nerve (cranial 12), voluntary control of tongue movement was enabled by the frontal lobe’s primary motor cortex. In humans, voluntary control of mammalian-inspired tongue movements was recruited for speech. Regarding spoken language, therefore, tongue dexterity may be considered a necessary, but not sufficient, step toward vocalizing words in Homo.
Step 6 (65 million years ago): Primate Binocular Vision
Summary. A stereoscopic view makes physical objects more visibly “real.” Binocular vision is highly adapted in arboreal, tree climbing primates. Seeing branches, berries, and insects from two angles at once provides a greater depth of field than does monocular vision, and enables greater “object integrity.” Seen in the round, physical objects stand out and have a clearer, sharper image, a visually more objective presence to which verbal names may be affixed. In primates, modules of inferior temporal cortex work in tandem with the occipital lobe for better object recognition, heightened response to hand shapes and gestures (Steps 7 and 11), and the ability to recognize facial expressions (Step 9).
One of language’s paramount jobs is naming objects and describing their properties in space-time (Steps 11 and 13). Stereoscopic vision may thus be considered a necessary, but not a sufficient, condition for the origin of manually signed and spoken words in language.
Step 7 (65 million years ago): Primate Grasping Hands
Summary. Object integrity was further enhanced in primates by prehensile hands. In tandem with binocular imaging, grasping a tree limb with fingers and palms makes the branch seem more tangible still, and, eventually in humans, more name-worthy as well. Sensorimotor cortical brain areas serving hands enlarged and improved the primate facility of palpating, exploring, and manipulating physical objects.
The 27 bones, 33 muscles and 20 joints of the human hand originated some 400 million years ago from the lobe fins of early fishes known as rhipidistians. Primeval swim fins helped our aquatic ancestors paddle through Devonian seas in search of food and mates. In amphibians, forelimbs evolved as weight-bearing platforms for walking on land. In primates hands became grasping organs, and were singled out for upgrade as tactile antennae or "feelers."
Infancy. Human babies are born with the primate ability to grasp objects tightly in a climbing-related power grip. Later, they instinctively reach for items placed in front of them. Between 1-1/2 and 3 months, reflexive grasping is replaced by an ability to hold-on by choice. Voluntary reaching appears during the 4th and 5th months of age, and coordinated sequences of reaching, grasping, and handling objects are seen by 3-to-6 months, as fingertips and palms explore the textures, shapes, warmth, wetness, and dryness of the material world in their reach space(Chase and Rubin 1979).
By 5 months, as a prelude to more expressive mime (pantomime) cues, babies posture with arms and hands as if anticipating the size and hardness or softness of objects (Chase and Rubin 1979). Between 6 and 9 months, infants learn to grasp food items between the thumb and outer side of the index finger, in an apelike precursor of the precision grip. At this time, babies pull, pound, rub, shake, push, twist, and creatively manipulate objects to determine their look and feel.
Hands and objects. Eventually a baby's hands experiment not only with objects themselves but with component parts, as if curious to learn more about how things fit together (Chase and Rubin 1979). At one year, infants grasp objects between the tactile pads of thumb and index finger, in a more mature, distinctively human precision grip. Pointing with an extended index finger (Step 13) also begins at 12 months, as babies use the cue to refer to novel sights and sounds, and speak their first words.
Manual intellect and emotion. Today in humans, fingers (unlike flippers, claws, or hooves) link to intellectual modules and emotion centers of the brain. Not only can we thread a needle, for example, we can also pantomime the act of threading with our fingertips--or reward a child's successful threading with a gentle pat. The primate ability to palpate, explore, and manipulate physical objects with the hands is yet another necessary, but not sufficient, condition for manual signing and speech.
Nouns
Verbs
Adverbs
Prepositions
A word that in some languages is placed before a noun indicating its relationship to another noun, a verb, or adjective. American English examples include "at," "by," and "in."
Step 8 (65 million years ago): Primate Dexterous Lips
Summary. When not opening or closing a mouth, fish lips are rigidly fixed in place. In mammals, lips become mobile and connected to enlarged sensorimotor centers designed to contract muscles to form a sphincter-like seal around a mother’s breast for sucking. In primates lips become more dexterous still, and are recruited for audiovisual signaling in vocal calls (as in Alouata sp., the howler monkey) and facial expressions (as in chimpanzees).
Precision. To the dexterity of primate lips, humans add even greater precision for speech. Lip movements for speaking are controlled by Broca’s premotor area via the frontal lobe’s primary motor cortex. The principal lip muscle, orbicularis oris, is a sphincter consisting of pars marginalis (beneath the margin of the lips themselves), and pars peripheralis (around the lips' periphery from the nostril bulbs to the chin). P. marginalis is uniquely developed in humans for speech.
Mirror neurons. In humans mirror neurons are present in the primary motor area, premotor system (including Broca’s area), and supplementary motor system (Kilner & Lemon 2013). In monkeys mirror neurons have been found to fire both when food is brought to the mouth with a hand and when others are seen performing the same actions. But “. . . the most effective visual stimuli in triggering [the actions],” Ferrari and colleagues note, “are communicative mouth gestures (e.g. lip smacking)” (Ferrari et al. 2003, p. 1703). “Some also fire,” they add, “when the monkey makes communicative gestures. These findings extend the notion of mirror system from hand to mouth action and suggest that area F5, the area considered to be the homologue of human Broca's area, is also involved in communicative functions” (p. 1703). Thus, well before vocal or gestural language itself, primate lips and hands had been pre-adapted for social expression.
Consonants and vowels. In speaking, lips form bilabial English consonants--such as /b/, /p/, /m/, and /w/--in which respiratory airflow is stopped or restricted. Lips also form the rounded English vowels /o/ and /u/. Words with bilabial consonants in Asian languages include ”peeyah” (Burmese “pya,” bird), “beeyah” (Tibetan “bia,” bird), and “barf” (Brahui “barf,” snow; Ruhlen 1994, p. 44). Also in Asian languages, words with rounded vowels include “shayool” (Yukaghir “seul,” stone), “toe” (Tibetan “to,” stone), and “geyou” (Yaou “gyou,” stone; Ruhlen 1994, p. 44). Without their dexterous primate lips, humans would be unable to produce such sounds. Thus, dexterous lips may be considered a necessary, but not a sufficient, condition for the origin of language.
Step 9 (35-40 million years ago): Higher Primate Facial Communication
Summary. Higher primate (Anthropoidea) precursors had an enlarged visual cortex on the occipital lobe for processing color vision and depth. Today the anthropoid's is the most complex visual cortex yet developed, with anatomically separate areas for analyzing form, coordinating hand-and-eye movements, and recognizing faces. In human anthropoids, a few nerve cells in the lower temporal lobe are narrowly specialized to respond only to hands and faces (Kandel et al. 1991, p. 459).
Reading hand gestures and facial expressions enabled listeners to discern emotion behind signed and spoken words. Gestures and facial cues add emotion through increased levels of the social-bond-stimulating neuropeptides oxytocin and vasopressin. Faces are decoded in the anterior inferotemporal cortex; facial familiarity registers in the superior temporal polysensory area (Young & Yamane 1992). Emotional impacts of facial messages register in the amygdala.
A synergistic relationship likely obtained between facial messaging and eye contact. Extended eye contact between speaker and listener in face-to-face conversations may have enhanced face reading. Face reading in turn likely heightened eye contact. Reading lips (Step 8) is especially germane in speech. Functional MRI studies of speaking show that visual cues afforded by lip movements activate areas of auditory cortex in normal hearing individuals (Calvert et al. 1997). Since face-to-face linguistic dialogue would not likely have developed without an ability to read facial expressions, it is proposed that facial cues represent a necessary, but not a sufficient, condition for language.
Step 10 (24 million years ago): Primate Food Sharing
Summary. Sharing food items provided a model for the give-and-take, back-and-forth turn-taking of language. Physical closeness occasioned by food-sharing likely stimulated maternal-offspring communication. As in later speaking, food-sharing had a clearly emotional dimension. Both forms of expression are made more pleasurable by raised levels of the neuropeptides oxytocin and vasopressin. As indicated above (Step 4), the brain’s cingulate cortex has been implicated in maternal caring, grooming, and audiovocal signaling (MacLean 1990), each of which contributed to eventual speech.
Primate food sharing is an extension of the mammalian practice of providing mother’s milk. Maternal sharing with offspring of foods in addition to milk is widespread, occurring in 39 species of primates out of 69 sampled (Jaeggi & Gurven 2013). Old World monkeys and prosimians are least likely, while New World monkeys, all ape species, and humans are most likely, to share food with offspring.
Grunts and girneys. Maestripieri (2011) proposes that adult female primates are attracted to an infant’s facial appearance and coo vocalizations, finding these signs emotionally pleasing as brain opioids and oxytocin are released. Females may respond to infants by lip-smacking and vocalizing with grunts and girneys. Grunts are “brief bark-like atonal sounds,” while girneys are “nasal ‘singing‘ noises” (Maestripieri 2011, p. 520).
Gibson suggests that language evolution may have begun with food-sharing and simple one-or-two-word sentences exchanged by mothers with offspring. Tool-use likely played a role in the exchange. Early hominid mothers, she notes “. . . may have extracted and processed foods using tools and then shared the food with offspring incapable of tool use themselves. Such food sharing may have selected for communication capacities similar to those of children learning to talk. . .” (Gibson 1993, p. 266). The back-and-forth, turn-taking pattern inherent in sharing food items--combined with its emotional closeness--may be necessary, but not sufficient, for later turn-taking in language.
Step 11 (2.6 million years ago): Human Tool Making
Summary. Humans use and make stone tools. Flaking a tool and uttering a word use some of the same and closely related brain areas. So nearly alike are neural pathways for manual dexterity and articulate speech that a stone tool may be deciphered as if it were a petrified phrase. English "handaxe," for example, and the perception of the worked stone for which it stands, both exist as mental concepts whose neural templates are linked in the brain. "When an object is seen or its name read, knowledge of attributes is activated automatically and without conscious awareness" (Martin et al. 1995, p. 102). Broca’s area, the premotor-cortex module that governs language production, has been implicated in tool-making as well (Stout and Chaminade 2011). As Hauser noted, "When we create an artifact such as a tool, we leave a physical trace of our thoughts" (2000, p. 22).
Intelligently fabricated. In accord with Gibson’s (1993) linkage of tool use and food sharing, there is general agreement that human artifacts and tools played a major role in the origin of language (Gibson and Ingold 1993). An artifact is a material object (e.g., a bifacial stone tool) deliberately fabricated by humankind. Like gestures, artifacts have a great deal to "say." That they are intelligently fabricated is evident in their deliberately patterned shape, grammatical syntax (structured arrangement of parts), and orderly negative entropy in design.
English artifact comes from Latin arte ("by skill") and factum ("made"; via the ancient Indo-European root dhe-, "to set," "put," derivatives of which include deed, did, and do; skill "by hand" is implied). The earliest known artifacts come from Africa. At numerous sites from that continent sharply flaked stone tools have been found, dating back some 2.6 million years before present (Gibbons 1997).
While chimpanzees use stone tools, they do not make them. In Africa, chimpanzees shell panda nuts (Panda oleosa) together in the Tai forest of Ivory Coast. The chimps socialize as they crack the nuts’ hard shells with heavy, unworked stones, carefully placing each nut in a knothole before smashing it. Young chimpanzees watch their mothers, and after years of trial and error, learn to master the stone technology and crack the shells on their own. The learning curve is steep, but mothers share panda nuts with their own offspring as the latter learn (Boesch and Boesch-Achermann 2000). While there is a visible give-and-take in the dialogue as mother and offspring share food and the chopping-stone tool, few vocalizations are given by either party.
Mental concepts. Speech involves the ability to pair stored mental concepts with incoming data from the senses. Ivan Pavlov observed dogs in his laboratory as they paired the sound of human footsteps (incoming data) with memories of meat (stored mental concepts). Not only did meat itself cause Pavlov's dogs to salivate, but mental concepts of meat--memories of mealtimes past--were also called up by the sound of human feet. Pairing one sensation with memories of another--the process of sensitization or associative learning--is a fundamental ability given even to sea slugs (Nudibranchia).
In humans, tool use likely increased mental concept formation. MRI studies reveal that children who make early, skilled use of the digits of the right hand (e.g., in playing the piano) develop larger areas in the left sensory cortex devoted to fingering (Karni et al. 1998). Thus, Pleistocene youngsters precociously introduced to tool making may have developed enhanced neural circuitry for the task.
Mirror neurons. There is growing evidence, as well, of a role for mirror neurons in speech. "Taken together,” Iacoboni (2008) writes, “all these data show that gestures precede speech and that mirror neurons are probably the critical brain cells in language development and language evolution" (p. 87). As Egolf notes: "Gestures lead then speech follows, suggesting further that mirror neurons are critical for speech and language development. The interdependence of speech and gesture dashes some cold water on the espoused dichotomy between verbal and nonverbal communication" (2012, p. 90).
Controlled by the prefrontal cortex, an ability to manage the sequence of body movements required for tool making was a likely necessary, but not a sufficient, precursor to articulate sequencing in language.
Grammatical sequences
Step 12 (1.9 million years ago): Object Fancy
In more severe forms [of the grasping reflex], any visual target will elicit manual reaching followed by tight grasping. --M. Marsel Mesulam (1992, p. 696)
Summary. In genus Homo the manufacture of stone, bone, wood, and other material artifacts was followed by a curious attraction to the artifacts themselves called “object fancy” (Givens 2008, p. 190). Object fancy is the desire to pick up, handle, and hold a material object, especially a consumer product of elegant design. It includes the urge to touch, own, arrange, collect, display, or talk about a manufactured artifact. Rooted in the grasping reflex, object fancy involves a balance between the parietal lobe's control of object handling and the frontal lobe's "thoughtful detachment" from the material world of goods (Mesulam 1992, p. 697).
Material gestures. Human-made items call attention to themselves through their structured design. Products "speak" to us nonverbally as tangible, material gestures. Their design features (e.g., the shine, shape, and smoothness of a platinum bracelet) send compelling messages that capture our attention. We pick them up to answer their call.
Names. Dialogue with objects commences at infancy. Communication with and about material things begins around six months of age (Trevarthen 1977). This early interaction with objects takes place in a context of social communication with caregivers, in tandem with the latter’s words. Repeated pairing of diverse objects with parental linguistic labels reinforces the notion that the objects at hand have names.
The linguistic power of object names is clear in the case of Helen Keller. Blind and deaf at 19 months of age, Keller’s path to language was severely impaired. To compensate for the disabilities, her teacher would finger-spell letters into Keller’s hand for environmental items such as tap water, a household mug, and a toy doll. After weeks of finger-spelling names like “d-o-l-l” into Keller’s hand, she grasped the idea that the objects in her world had unique names. Understanding this basic fact enabled Keller ultimately to achieve linguistic competence.
Magnetic effect. According to Mesulam, there exists a "magnetic effect triggered by objects" that originates with the brain’s innate grasping reflex (1992, p. 697). Subsequently it involves a balance between the parietal lobe's control of object fancy, and the frontal lobe's inattention to material goods. In patients with frontal lobe lesions, the mere sight of an artifact is "likely to elicit the automatic compulsion to use it," while lesions in the parietal network "promote an avoidance of the extrapersonal world" (Mesulam 1992, p.697).
Stone tools. The extrapersonal world of artifacts begins with stone tools. Dated to 2.6 million years ago, among the earliest known consumer products are intentionally flaked Oldowan pebble tools from Ethiopia, produced by Homo habilis. By 1.6 million years ago, a more eloquent, fist-sized hand-axe bearing a standardized, symmetrical, leaf-shaped design was being chipped in East Africa by Homo erectus. Known as Acheulean bifaces, these artifacts exhibited “elegant bilateral symmetry and overall regularity of form” (Ingold 1993, p. 337).
A likely artistic concern with form may have exceeded functional needs, and these early artifacts--which have been found on three continents--likely had names as well. So beautifully constructed, some Acheulean specimens may have been regarded as heirlooms and exchanged, much as ornamental shell bracelets were given and taken in the Trobriand Island Kula trade (Malinowski 1922).
Consumer products. Since the Stone Age, the number of consumer products invented and used by Homo sapiens--from Silly Putty to interstate highways--has increased at a rate three times greater than biological evolution (Basalla 1988). As the human brain and body were shaped by natural selection, consumer goods adapted to the mind through a parallel process of product selection, rendering them ever more fluent, expressive, and fascinating to the senses.
As shopping malls attest, object fancy prospers in the modern world. The average U.S. household stockpiles a greater supply of consumer goods than its members use. By age five, the average U.S. child has owned some 250 toys (Rosemond 1992). Among three to five-year-old children in preschools, fights occur over property and little else (Blurton Jones 1967).
In contrast to Americans, Tasmanian islanders off the southeast coast of Australia are among people who made and used the fewest number of artifacts. In all, Tasmanians used a total of some 25 stone and wooden tools, fiber baskets, shell necklaces, and bark canoes (Diamond1993). And yet, the contrast between U.S. urban consumers and Tasmanians is not marked, since the total time spent handling, repairing, exchanging, and communicating about (and with) artifacts may be roughly the same everywhere.
Consider Tibet, where material goods are relatively scarce yet resident Buddhists spend hours a day spinning prayer wheels. Made of metal, wood, or paper, the wheels have verbal mantras (Om Mani Padme Hum) written on the outside and included within. Users turn the cylindrical wheels with their fingers and voice the mantras as they spin. Nowhere is the link between object fancy and spoken word more clearly evident.
Step 13 (1.9 million years ago): Pointing--“It is there” (Advent of “That”)
Summary. A referentially pointed finger shows that advanced centers of the neocortex have been engaged. As a skilled gesture, pointing involves the supplementary motor area (SMA, which programs the sequence of arm, hand, and finger movements), the premotor cortex (which orients the arm movements), and the primary motor cortex (which programs the direction a gesture may take). In turn, the frontal cortex receives visual information about persons, places, and things from the posterior parietal lobes. While the left lobe involves language processing, the right processes spatial information to guide a pointed finger in the right direction. Like aphasia (the inability to speak), apraxia is an inability to point. That both are brought on by injuries to the cortex’s left side marks the similarity between voluntary pointing and language.
Referential pointing. Extending an index finger to call attention to objects and features of the environment is a gesture unique to human beings and captive chimpanzees (Leavens et al. 2005). Since it refers to the outside world, the referential point is a high-level, language-like gesture. In human infants, the referential point first appears around 12 months of age in tandem with the first use of words. Prior to speech itself, pointing is a reassuring sign of an infant's language ability. While some animals, including honeybees, can refer to environmental features, only humans (and infrequently, chimps) point them out with fingers.
All four fingers (the thumb has its own extensor muscles) may be extended in a coordinated way by contracting the forearm's extensor digitorum muscle. The index finger, however, has an extra forearm muscle (extensor indicis), which enhances the neural control of its muscular ability to point.
Alternate pathways. Early pointing is clearly emotional as toddlers point to share excitement with adults nearby. An excited child may extend an index finger toward a butterfly or chirping bird as mother watches, smiles, and articulates the creature’s name. Later in life, the gesture is controlled by more recent, advanced non-emotional modules of the brain. Nerve fibers from the latter’s primary motor area link directly to motor neurons, enabling the index finger to move deliberately and with precision. Long nerve fibers descend in a "mental expressway" which bypasses ancient brain-stem paths and fall directly onto the pointing digit. This more advanced pointing shows direct cortical control, as its neural pathway detours around older interneuron routes of the spinal cord.
Indexing. In American Sign Language “indexing” is the practice of using an extended index finger to point out personal and object pronouns, such as “I/me,” “you/you all,” “he/she/they,” and “it/them.” Pointing at persons and objects is also used in Plains Indian Sign Language. There is agreement among psychologists that referential pointing is a key to the development of language in infants (Leavens et al. 2005). Butterfield has called pointing “the royal road to language” (Butterfield 2003, p. 9).
With pointing, the conceptual transition from a personal “I am here” (Step 2) and “You are there” (Step 3) to an impersonal “It is there” is complete. In addition to calling attention to personal “I/me” and “you,” in Step 13 the members of Homo call attention to an impersonal “that.”
“That,” a word used to identify a person, plant, animal, or object observed by a speaker, appears in Swadesh’s (1971) list of the world’s 100 basic words. Superimposing communication about objects upon the earlier social communication about “I/me” and “you” was a significant step forward in the evolution of language. Like “I” and “you,” the elementary origin of “that” words is attested by their often simple phonetic, monosyllabic quality. In Eurasian language families, for instance, “that” is expressed variously by “toe” (Uralic “to”), “ha” (Khoisan “ha”), and “ta” (Altaic “ta”; Ruhlen 1994, p. 65).
Object words, in contrast, tend to be polysyllabic and phonetically more complex. Examples include ”keyahk” (Burmese “kyauk,” stone), “dantan” (Avestan “dantan,” tooth), and “tooloog” (Altaic “tulug,” feather; Ruhlen 1994). Recall Gibson’s suggestion (Step 10) that language evolution may have begun with food-sharing and simple one-or-two-word sentences.
Palm-up-and-down gestures. Referential pointing is more recent than, and contrasts with, earlier palm-up and palm-down communicative human signs. The latter hand signals--which are still in use today--may be regarded as gestural fossils left over from the original vertebrate system of communication about matters of social relationship (for an overview, see Givens 2015). Palm-up-and-down gestures are remnants of the ancestral articulators and may be used to reflect back on the social messages human forebears exchanged before the advent of pointing, languages, and words.
Stimulated by humankind’s seeming fascination with tangible objects that can be held in the hand, and by the fabrication of material artifacts and stone tools, ancestors of Homo sapiens gradually extended the use of pectoral-related body movements and laryngeal vocalizations for social communication to communication about objects and their features, and to the interrelationships of these in space-time. The ancient bodily articulators for linguistic communication were likely there from the beginning. Indeed, human gestural and spoken language was superimposed upon the earlier prelinguistic system of vertebrate social communication to which--by their current widespread use in face-to-face conversations--palm-up-and-down gestures strongly allude.
Referential pointing may be considered a necessary, but not a sufficient, mechanism for the development of linguistic communication.
Step 14 (1.9 million years ago): Human Cranial Capacity Increase
Summary. With Homo erectus the human brain enlarged from the apelike brain size of pre-erectus hominids. The corticobulbar nerve tract evolved; corticobulbar pathways to the facial nerve (cranial VII) permitted intentional facial expressions such as the voluntary smile. Broca's cranial pathways grew from a Broca's-area homologue via corticobulbar pathways to multiple cranial nerves, permitting human speech production. Broca's spinal pathways also evolved. Broca's-area circuits passing through corticospinal pathways to cervical and thoracic spinal nerves permitted manual sign language and linguistic-like mime (pantomime) cues. A Wernicke’s-area homologue grew to process incoming speech-like sounds.
The human brain began to enlarge between Steps 11 and 15--after tool-making and before signed/spoken language. Substantial enlargement took place in the cerebral neocortex, in association cortices responsible for the cognition and motor planning required for manufacturing tools. Motor systems for voluntary control of hand, lip, and tongue movements enlarged. In charge of the sequencing required for tool-making, and later for speech, the prefrontal cortex also grew.
Along with the cortex, diverse subcortical brain areas enlarged for the hand-eye coordination needed in tool-making. The emotional limbic system grew in tandem with the cerebral cortex (Armstrong 1986; see Step 4), making Homo sapiens the most emotional, intelligent--and fluent--species on earth.
Regarding signed and spoken words, the increase in human cranial capacity may be regarded as a necessary and sufficient condition for the development of language.
Step 15 (200 thousand years ago): Sonorous Human Larynx
Summary. In this step human vocalization becomes increasingly melodic, harmonious, and oratorical. The rationale for vocal softness and melody most certainly involved serenading in courtship. As it became more verbally linguistic, human courtship signaling likely favored vocal tenderness over harshness. The former voice quality is contact-inviting while the latter promotes distance.
Unlike wooden or metal tubes of a pipe organ, the human windpipe is pliable and protean in its ability to change shape. Encased in cartilage, the vibrating vocal folds produce sounds modified by elastic, membranous tissues and supple ligaments, further modified within mobile, mucus-lined pharyngeal, nasal, and oral chambers of the head. The musicality of human voices is processed in the planum temporale, a cortical auditory area found only in great apes and Homo.
Prosody. Compared to the harsh, often screaming vocalizations of chimpanzees, laryngeal-speech sounds produced by humans are softer, more sonorous, and more melodic in tone. Exemplars of today’s voice qualities include the eloquence of Martin Luther King in his “I Have a Dream” speech, Maya Angelou’s lyrical reading of her poem, “Phenomenal Woman,” and Luciano Pavarotti’s operatic rendition of “Serenade.” Each is delivered with vocal melody and lyrical motions of the fingers and hands.
Linguists call the quasi-musical qualities of human speech prosody. English “prosody” comes from Greek prosoidia, “song sung to music” or “accent.” Linguistic prosody includes accentuation, phrasing, rhythm, stress, and the tonal qualities of speech. On the nonverbal side, prosody includes the duration, muscular tension, and rhythm of hand movements that accompany words. Vocal and gestural prosody play important roles in the production and perception of human communication. Through them we detect emotions such as happiness, sadness, anger, fear, and uncertainty (Step 4) in utterance and gesture.
Serenade. Evolutionary reasons for vocal softness and melody involve serenading in courtship. Recall that from the beginning of life, intra-species communication has served a reproductive function (Step 1). In living primates, vocalizations including the gorilla’s “pant grunt,” the lemur’s “moans” and “meows,” and the tarsier’s “chirruping” calls are auditory courting signals. Again, as courtship became more verbally linguistic in humans, its signaling likely favored vocal tenderness over vocal harshness. The former invites closeness and contact while the latter promotes distance and separation. As Love Signals noted, “In courtship a softer, higher-pitched voice--the voice adults use with young children and pets--communicates an attitude of personal caring. Its lighthearted tenor is cheerful, calming, and universally friendly” (Givens 2005, pp. 85-6).
That speech has a reproductive function is evident in changes in the human voice at puberty. At the onset of reproductive age, male voices deepen through a lowering of the larynx and significant enlargement of its vocal folds. Deeper vocalizations are a vertebrate ploy for males to seem stronger and more daunting to rivals. "The more threatened or aggressive an animal becomes,” Hopson writes, “the lower and harsher its voice turns--thus, the bigger it seems" (1980, p. 83). In courtship, meanwhile, deeper vocalizations can be attractive. Female bullfrogs, for instance, swim toward males with the deepest calls. In humans, deeper-voiced males have been found to father more offspring (Apicella, Feinberg, and Marlowe 2007).
Since the sonorous human larynx likely developed after the brain enlargement of Homo erectus, it is neither a necessary nor a sufficient reason for the origin of language, but rather is a modification after the fact. In this sense it is like writing, an extension of language but not a cause.
Conclusion: Verbal Areas (200 thousand years ago)
Added value. Each of the 15 language steps physically worked its way into tissues of the human nervous system. Adaptively, each step added value by conferring greater access to environmental energy (e.g., through food extraction via tools) and social resources (via cooperation facilitated through communication). Favoring survival--whether through chemical signs of presence, visible signs of emotion, or audible signs of food sharing--each step conferred an adaptive advantage. Across millions of years, those benefitting from innovations within a given step came to outnumber those who did not. Physical changes in the nervous system were thus passed ahead in time to the present day.
Verbal area. A component of the brain, such as
Broca's or Wernicke's area, which governs the use of manually
articulated (i.e., signed) or vocally articulated (i.e., spoken) language. Also, an association (arcuate) fiber
link, such as the arcuate fasciculus, connecting verbal components.
Usage: Verbal centers are used to control the production and/or
comprehension of linguistic communication and words.
Hypothesis. Speech seems to
have evolved its own specialized sensorimotor production-and-decoding system
(see below, Embryology and Neuro-notes)--above and beyond that
which is used for nonverbal expression (see below, Nonverbal communication
areas). However, speech has not evolved its own semantic information
content. The latter is housed in brain modules (e.g., of the parietal
association areas and the frontal lobes) which are shared by verbal and
nonverbal media alike. Thus, speech is special but not that special.
KNOWN VERBAL CENTERS
Angular gyrus. A visible bulge
on the cerebral cortex marking regions of the occipital, parietal, and temporal
lobes (behind Wernicke's area) which links visual word recognition with other
linguistic abilities.
Arcuate fasciculus. A tract of association
fibers connecting Broca's and Wernicke's areas. In a less robust form, the
arcuate fasciculus may predate--and thus may be a preadaptation for--speech.
Similar tracts of association fibers (the superior longitudinal fasciculus,
inferior longitudinal fasciculus, and uncinate fasciculus) found in the
right-brain hemisphere connect nonverbal centers of the cerebral cortex.
Basal ganglia. "It is likely that the enlargement of the
prefrontal cortex reflects, in part, its role in speech production. The rewiring
appears to involve the basal ganglia; data from recent comparative studies
suggest that basal ganglia circuits may be the key to the unique brain bases of
human speech and syntax" (Lieberman 1991:106-07).
Broca's
area. A premotor module of the neocortex (in the lower lateral frontal
lobe; specifically, Brodmann's areas 44 and 45) identified in 1861 by Paul Broca
as essentially involved in the production and control of human speech. Damage to
this area (called Broca's aphasia) produces problems in speaking (while
comprehension of another's speech is left unimpaired). "Broca's region encompassing Brodmann's cytoarchitectonic areas 44 and 45 in the left hemisphere, with representations of face, head, and hands--but not of foot--may have evolved into a special communication area relying on orofacial gestures and hand movements" (Nishitoni et al. 2005, p. 66)." According to Philip
Lieberman, Broca's area ". . . has no functional equivalent in nonhumans"
(Lieberman 1991:24; but see below, Evolution I and II). Recently,
a language module immediately anterior to Broca's area has been identified,
which suggests that the Broca module may be involved in sequencing complex
articulations which are not just limited to speech. Broca's area does not seem
to control syntax (i.e., the combinatorial or grammatical arrangement of speech
elements; see below, Neuro-notes II).
"A growing body of neuroimaging evidence indicates that Broca's area, in addition to its linguistic functions, appears to be engaged in several cognitive domains. These domains include music, working memory, and calculation" (Fadiga et al. 2009, p. 451). "Accordingly, it has been demonstrated that during the observation of meaningless gesture there was no Broca's region activation when compared with transitive (goal-directed) gestures, and that a meaningful hand-object interaction is more effective in triggering Broca's area activation than is pure movement observation" (Fadiga et al. 2009, p. 452). From a study of Broca's area homologues in chimpanzees (Pan troglodytes), in which no differences were seen in left- and right-side hemispheres, ". . . it appears that the specialized role of Broca's area in human language might have been built upon a preexisting function of the inferior frontal cortex that is shared with other Old World primates for the planning and recognition of hand and mouth action sequences" (Schenker et al. 2010).
Insula. Some regard
the insula as a verbal center (see, e.g., Ardila 1999). Damage to the left
insula may result in language disturbances, including Broca's aphasia,
conduction aphasia, speech apraxia, mutism, and the word-deafness of Wernicke's
aphasia (Ardila 1999). ("Then on the other hand, recent studies of anatomical
connections of the insula point to an important viscero-limbic role and it has
been suggested that the insula may influence verbal motivation and verbal
affect" [Ardila 1999].)
Planum temporale. "The planum temporale
(PT) is a key site within Wernicke's posterior receptive language area in the
left hemisphere of the human brain and is thought to be an epicenter within a
dispersed mosaic of language-related regions in the cerebral cortex. The left
hemisphere predominance of the PT is more pronounced than any other human brain
asymmetry" (Gannon 1998:220). (See below, Neuro-notes.)
Wernicke's area. A supplementary-auditory module of the neocortex
(in the left temporal lobe; specifically, Brodmann's areas 39, 40, posterior 21
and 22, and part of 37) identified as involved in the understanding of auditory
words. Damage to this area (called Wernicke's aphasia) produces problems in
deciphering the meanings of the speech sounds one hears (even of one's own
speech sounds). According to a recent study, Wernicke's area is not unique to
Homo (see below, Neuro-notes).
Apes. Magnetic resonance imaging (MRI) scans of chimpanzees, bonobos,
and gorillas suggest that, like humans, these great apes also have an enlarged
Brodmann's area 44 (part of Broca's area in the human brain). Writing in the
journal Nature (2001), Claudio Cantalupo and William Hopkins (Emory
University and Georgia State University) suggest the brain homologue may be due
to a link between primate vocalization and gesture. Captive apes, the
researchers note, usually gesture with the right hand as they
vocalize.
Embryology. 1. "It is important to recognize
that the speech areas of the human brain are already formed before birth . . ."
(Eccles 1989:87). 2. The temporale plane is larger in the left fetal
brain hemisphere than in the right (Stromswold 1995). 3. "Development of
the cortical regions that subserve language in the left hemisphere consistently
lags behind the development of the homologous regions in the right hemisphere
[to await speech development]" (Stromswold 1995:860).
Evolution I. 1. "The evolutionary origin of human language
may have been founded on this basal anatomic substrate, which was already
lateralized to the left hemisphere in the common ancestor of chimpanzees and
humans 8 million years ago" (Gannon 1998:220). 2. Regarding endocasts of
Homo habilis skulls: "There was a further development of the inferior
frontal lobule in the Broca area, but most remarkable was the rounded fullness
of the inferior parietal lobule [corresponding to part of Wernicke's area]"
(Eccles 1989:23).
Evolution II. In non-human primates, Broca's
area controls muscles of the face and vocal tract. 1. "The homologue of
Broca's area in nonhuman primates is the part of the lower precentral cortex
that is the primary motor area for facial musculature" (Lieberman 1991:106).
2. In monkeys, the link between Broca-like and Wernicke-like areas is not
as massively connected as it is in humans (Aboitiz and Garcia
1997).
Evolution III. "However, both classes of stimuli [vocal-auditory and gestural-visual] activate a common, left-lateralized network of inferior frontal and posterior temporal regions in which symbolic gestures and spoken words may be mapped onto common, corresponding conceptual representations. We suggest that these anterior and posterior perisylvian areas [Broca's and Wernicke's, respectively], identified since the mid-19th century as the core of the brain's language system, are not in fact committed to language processing, but may function as a modality-independent semiotic system that plays a broader role in human communication, linking meaning with symbols whether these are words, gestures, images, sounds, or objects" (Xu et al. 2009).
Nonverbal communication areas. With regard to language,
relationships between the right (nonverbal) and left (verbal) hemispheres are
still poorly understood, with more deference being paid by researchers to the
left-hand (i.e., dominant) side. 1. In the right cerebral hemisphere,
modules control the production and interpretation of the nonverbal communication
that accompanies words, e.g., facial
expressions, voice tones, and gestures of the arms and hands. (Some of the latter, hand,
gestures are actually more verbal than nonverbal [see, e.g., MIME
CUE].) 2.Prosody--the emotional content of
speech--is right hemispheric in human beings with left-hemisphere verbal
centers. 3. The right (or non-dominant) hemisphere is less involved in
literal meanings of a speech element than it is with interpreting the figurative
meanings conveyed by, e.g., hesitations, humor, metaphor, poetry, and voice
tone. 4. Damage to the right parietal lobe's angular gyrus and
supra-marginal gyrus results in a. problems using spatial concepts,
b. difficulties dressing one's own body, c. feeling spatially
disoriented, d. inability to draw simple 3D pictures, and e.
neglect of left-handed body parts and objects to the
left.
Stuttering. "But the stutterers were far less left-dominant;
activation in their brains was shifted toward the right in both the motor and
auditory language areas, revealing an inherent difference in the way the two
groups [normal and stutterers] process language" (Barinaga 1995:1438).
E-Commentary: "I have two
questions about the arcuate fasciculus, the fiber bundle from Wernicke's area to
Broca's area. Can anyone help me? 1. Are there also fibers going in the opposite direction, from Broca's
area to Wernicke's (we know that many cortico-cortical connections are
bidirectional--what about this one?)? 2. How many fibers are we talking about? 3. A third question: What can anyone tell me
about connections between Wernicke's area and the angular gyrus? (Bidirectional?
How many fibers?) Thanx loads." --Syd Lamb, Linguistics and Cognitive Science,
Rice University Houston TX 77251-1892 USA; smlamb@OWLNET.RICE.EDU (Sydney M
Lamb) (Tue Jan 30 14:02:03 1996) Neuro-notes I. In most humans, Wernicke's area is significantly
larger in the left hemisphere than it is in the right. Its asymmetry dwarfs that
of most other cerebral-cortex modules. And yet, though specialized for language,
Wernicke's area is not unique to Homo. Recently, e.g., Patrick Gannon and
his colleagues measured the corresponding area of chimpanzee brains. After
spreading apart 15 chimp brains at the temporal lobe (i.e., at the sylvian
fissure), they measured the planum temporale, and found it to be larger on the
left than on the right in 14 cases (Gannon et al. 1998).
Neuro-notes
II. "Lesions to Broca's area and its vicinity do not affect semantic
abilities, nor do they disrupt basic syntactic abilities. Most notably, Broca's
aphasics combine lexical meaning into propositions, create and analyze sentences
of considerably complex structure, and are also able to synthesize and analyze
words morphophonologically. It thus follows that most human linguistic
abilities, including most syntax, are not localized in the anterior language
areas--Broca's area and deeper white matter, operculum, and anterior insula"
(Grodzinsky2000).
Neuro-notes III. 1. "We can assert
unequivocally: no combinatorial language abilities reside in the non-dominant
cerebral hemisphere" (Grodzinsky2000). 2. "Thus the evidence is that this
side of the brain has an important an role in communication, but makes no
syntactic contribution to language use" (Grodzinsky2000).
Neuro-notes
IV. "However, it should be kept in mind that neither of the classical
language areas, Broca's area and Wernicke's area, are cortical areas in the
strict sense in which the term area is used by an [sic] neuroanatomist. For
example, they are not defined according to the same strict and multiple criteria
that are employed in defining primary visual cortex (area 17), and each includes
more than one architectonically distinct area" (Killackey 1995:1248).
Neuro-notes V. Mirror neurons: Mirror neurons may play an important role in Broca's area: A. Consider Maurizio Gentilucci's abstract for the 2012 conference on "Mirror Neurons: New Frontiers 20 Years After Their Discovery": "Studies of primate premotor cortex, and, in particular, of the so-called mirror system, including humans, suggest the existence of a double hand/mouth motor command system involved in ingestion activities. This may be the platform on which a combined manual and vocal communication system was constructed. . . . we suggest that this system evolved a system controlling words and gestures: we propose that this system is located in Broca's area." B. ". . . Broca's area activates when subjects observe another individual speaking without hearing the sound . . ." (Fogassi and Ferrari 2007:139).
Neuro-notes VI. Mirror neurons: Broca's area mediates the production of speech as well as certain hand movements: "First, area F5 [of the monkey premotor cortex (which is homologous with our Broca's area)] contains motor neurons related to the execution of both hand and mouth actions. Similarly, brain-imaging experiments in humans demonstrated that Broca's area, traditionally considered a 'speech' area, is also involved in hand-movement tasks such as complex finger movements, mental imagery of grasping actions, and hand-imitation tasks (Rizzolatti & Craighero, 2004)" (Fogassi and Ferrari 2007:139).
Synergy. Language is more than a simple sum of the 15 developmental steps outlined in this paper. An interplay among and between the steps--a synergy--is evident as well. Gibson (Step 10) suggests a synergy between food sharing and tools. Tool making and object fancy (Steps 11 and 12) may be synergistically linked, as may be binocular vision and facial messages (Steps 6 and 9). Emotion messages (Step 4) are synergistically linked to facial messages, food sharing, object fancy, and pointing (Steps 9, 10, 12, and 13, respectively). Future research on the interplay and possible synergy among language steps, played out over vast sums of time, would be helpful to explain the stunning linguistic fluency of our species.
Sequencing. Words are produced by articulated movements of the hands in signing and by the vocal tract in speech. Word order is overseen by circuits of prefrontal cortex, which guide the sequential mental processing needed to build an artifact or compose a worded phrase. Controlled by the frontal lobes, both hands and speech organs follow correct behavioral sequences required to articulate verbal statements and manufacture tools. Recall (Step 4) that emotional communication was shaped by social factors that reverberated in the cingulate gyrus for grooming and vocal calling. There is reliable evidence for distinct grooming sequences--for a richly patterned "grammatical" order--even in the facial-grooming behavior of mice (family Muridai; Stilwell and Fentress 2010).
The supplementary motor area (SMA) of the cerebral neocortex is involved in sequential processing, as well, both for verbal and for some nonverbal articulations (such as mime cues). In function, SMA coordinates and controls the sequencing of bimanual hand movements. Found only in primates, SMA has been well studied in humans and monkeys. Regarding the latter, "We have found a group of cells in the cerebral cortex of monkeys,” Tanji and Shima note, “whose activity is exclusively related to a sequence of multiple movements performed in a particular order. Such cellular activity exists in the supplementary motor area. . .” (1994, p. 413).
Genetics and archaeology. Thanks to Luigi Cavalli-Sforza, we now have population-genetic and archaeological evidence to factor into the language-origin issue. "The genetic information for this work came from a very large collection of gene frequencies for 'classical' (non-DNA) polymorphisms of the world aborigines. The data were grouped in 42 populations studied for 120 alleles. The reconstruction of human evolutionary history thus generated was checked with statistical techniques such as "boot-strapping". It changes some earlier conclusions and is in agreement with more recent ones, including published and unpublished DNA-marker results. The first split in the phylogenetic tree separates Africans from non-Africans, and the second separates two major clusters, one corresponding to Caucasoids, East Asians, Arctic populations, and American natives, and the other to Southeast Asians (mainland and insular), Pacific islanders, and New Guineans and Australians. Average genetic distances between the most important clusters are proportional to archaeological separation times. Linguistic families correspond to groups of populations with very few, easily understood overlaps, and their origin can be given a time frame. Linguistic superfamilies show remarkable correspondence with the two major clusters, indicating considerable parallelism between genetic and linguistic evolution. The latest step in language development may have been an important factor determining the rapid expansion that followed the appearance of modern humans and the demise of Neanderthals." Luigi Cavalli-Sforza (full citation forthcoming)
Among verbal areas proposed for language are three with little or no basis in neurology: (1) Language Acquisition Device (LAD), (2) Growth Point (GP), and (3) Language Instinct (LI). Proposed in 1965 by Chomsky, the LAD is an unidentified brain module that supposedly enables children to speak and understand the grammatical rules of speech. Introduced in 1992 by McNeill, the GP is an unidentified neural process in which, theoretically, speech, thought, and gesture are simultaneously unified. And, advanced in 1994 by Pinker, the LI is an unidentified mental module that presumably confers an innate ability to speak and understand words. Though provocative, none of these hypothetical verbal areas have empirical meaning in neuroscience.
From messaging molecules of cyanobacteria to prosodic features of manual signing and speech, pre-language- and language-scaffolding abilities have been programmed into the neuromuscular system. Human gestural and spoken communication was superimposed upon the earlier nonverbal systems of vertebrate social communication. Today’s linguistic channel reflects the earlier medium’s roles in self-assertion, species recognition, genetic reproduction, emotional expression, and attention to objects.
References
Apicella, C. L., Feinberg, D. R., and F. W. Marlowe. 2007. Voice pitch predicts reproductive success in male hunter-gatherers. Royal Society Bulletin (London; Dec. 22). [http://rsbl.royalsocietypublishing.org/content/3/6/682]
Armstrong, Este (1986). Enlarged limbic structures in the human brain: The anterior thalamus and medial mammillary body. Brain Research (Vol. 362, No. 2. pp. 394-97).
Basalla, George. 1988. The evolution of technology (New York: Cambridge U. press).
Bass, Andrew & Boris P. Chagnaud. 2013. Shared developmental and evolutionary origins for neural basis of vocal–acoustic and pectoral–gestural signaling. Proceedings of the National Academy of Sciences (http://www.pnas.org/content/109/suppl.1/10677.full [accessed August 23, 2013]).
Blurton Jones, N. G. 1967. An ethological study of some aspects of social behaviour of children in nursery school. In Desmond Morris (ed.), Primate ethology (Chicago: Aldine), pp. 347-68.
Boesch, Christophe and Hedwige Boesch-Achermann. 2000. The chimpanzees of the Taï Forest: Behavioural ecology and evolution (Oxford: Oxford U. Press).
Butterworth G. 2003. “Pointing is the royal road to language for babies.” In Kita S, (ed.), Pointing: Where language, culture, and cognition meet (Mahwah, NJ: Erlbaum), pp. 9–33.
Calvert, Gemma A., Edward T. Bullmore, Michael J. Brammer, Ruth Campbell, Steven C.R. Williams, Philip K. McGuire, Peter W.R. Woodruff, Susan D. Iversen, and Anthony S. David (1997). “Activation of auditory cortex during silent lipreading.” Science (Vol. 276, 25 April), pp. 593-96.
Cervantes, Miguel de (1605). Don Quixote (New York: Viking Press, 1949).
Chase, Richard A. and Richard R. Rubin. 1979. The first wondrous year (New York: Macmillan Pub. Co).
Chomsky, Noam. 1965. Aspects of the theory of syntax (Cambridge, Mass.: MIT Press).
Diamond, Jared (1993). “Ten thousand years of solitude.” Discover (March), pp. 48-57.
Egolf, Donald B. (2012). Human communication and the brain (Plymouth, U.K.: Lexington Books).
Ferrari, P. F., Gallese, V., Rizzolatti, G., and L. Fogassi. 2003. “Mirror neurons responding to the observation of ingestive and communicative mouth actions in the monkey ventral premotor cortex.” European Journal of Neuroscience (April), pp. 1703-14.
Freestone, Primrose. 2013. "Communication between Bacteria and Their Hosts." Scientifica (Vol. 2013) [https://www.hindawi.com/journals/scientifica/2013/361073/ (accessed Sept. 20, 2016)].
Gibbons, Ann. 1997. “Tracing the identity of the first toolmakers.” Science (April 4, Vol. 276), p. 32.
Gibson, Kathleen R. 1993. “Overlapping neural control of language, gesture and tool-use.” In Gibson, Kathleen R. and Tim Ingold (eds.), Tools, language and cognition in human evolution (Cambridge: Cambridge University Press), Part III Introduction, pp. 187-92.
Gibson, Kathleen R. and Tim Ingold (eds.). 1993. Tools, language and cognition in human evolution (Cambridge: Cambridge University Press).
Givens, David B. 1978. “The nonverbal basis of attraction: Flirtation, courtship, and seduction." Psychiatry (Vol. 41), pp. 346-59.
Givens, David B. 2005. Love signals: A practical field guide to the body language of courtship (New York: St. Martin's Press).
Givens, David B. 2008. Crime signals: How to spot a criminal before you become a victim (New York: St. Martin's Press).
Givens, David B. 2014. “Nonverbal neurology: How the brain encodes and decodes wordless signs, signals, and cues.” Ch. 1 in Kostic, Aleksandra & Derek Chadee (eds.). Social psychology of nonverbal communication (New York: Palgrave-MacMillan Press), pp. 9-30. To read this article, please click here.
Givens, David B. 2015. “Palm-up and palm-down gestures: Precursors to the origin of language.” Spokane, Washington: Center for Nonverbal Studies. [http://center-for-nonverbal-studies.org/57912.html (accessed Mar. 29, 2016)] (To view this article, please click here.)
Givens, David B. 2016. “Reading palm-up signs: Neurosemiotic overview of a common hand gesture.” Semiotica (forthcoming). [http://www.degruyter.com/view/j/semi.ahead-of-print/sem-2016-0053/sem-2016-0053.xml (accessed March 29, 2016)] (To view this article, please click here.)
Givens, David B. 2016. The nonverbal dictionary of gestures, signs & body language cues. Spokane, Washington, Center for Nonverbal Studies (www.center-for-nonverbal-studies.org/htdocs/6101.html; accessed March 26, 2016).
Hauser, Marc D. 2000. Wild minds: What animals really think (New York: Henry Holt and Company).
Hopson, Janet. 1980. “Growl, bark, whine & hiss: Deciphering the common elements of animal language.” Science 80 (May/June), pp. 81-4.
Iacoboni, Marco. 2008. Mirroring people (New York: Farrar, Straus and Giroux).
Ingold, Tim. 1993. “Introduction: Tools, techniques, and technology.” In Gibson, Kathleen R. and Tim Ingold (eds.), Tools, language and cognition in human evolution (Cambridge: Cambridge University Press), Part IV Introduction, pp. 337-45.
Jaeggi, Adrian V. and Michael Gurven. 2013. “Natural cooperators: Food sharing in humans and other primates.” Evolutionary Anthropology (Vol. 22), pp. 186–95.
Karni, Avi, Rey-Hipolito, Christine, Jezzard, Peter, Adams, Michelle M., Turner, Robert, and Leslie G. Ungerleider. 1998. “The acquisition of skilled motor performance: Fast and slow experience-driven changes in primary motor cortex.” Proceedings of the National Academy of Sciences (Feb. 3; Vol. 95, No. 3), pp. 861–68.
Kilner, J. M. and R. N. Lemon. 2013. “What we know currently about mirror neurons.” Current Biology (Vol. 23, Dec. 2), pp. 1057-1062. [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898692/ (accessed Mar. 18, 2016)]
Kringelbach, Morten L. and Kent C. Berridge. 2010. “The functional neuroanatomy of pleasure and happiness.” Discovery Medicine (June, Vol. 9, No. 49), pp. 579-87. [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3008353/ (accessed Mar. 21, 2016)]
Leavens, David A., Hopkins, William D., and Kim A. Bard. 2005. “Understanding the point of chimpanzee pointing: Epigenesis and ecological validity.” Current Directions in Psychological Science (Aug., Vol. 14, No. 4), pp. 185–89.
Levinas, Emmanuel. 1989. “The transcendence of words.” In Hand, Sean (ed.), The Levinas reader. Oxford: Blackwell, pp. 144-149.
MacLean, Paul D. 1990. The triune brain in evolution. New York: Plenum Press.
Maestripieri, Dario. 2011. “Emotions, stress, and maternal motivation in primates.” American Journal of Primatology (Vol. 73), pp. 516-29.
Malinowski, B. (1922). Argonauts of the Western Pacific: An account of native enterprise and adventure in the archipelagoes of Melanesian New Guinea (London: Routledge and Kegan Paul).
Martin, Alex, Haxby, James V., Lalonde, Francois M., and Cheri L. Wiggs. 1995. “Discrete cortical regions associated with knowledge of color and knowledge of action.” Science (Oct. 6, Vol. 270, Issue. 5233), pp. 102-05.
McNeill, David. 1992. Hand and mind (Chicago: University of Chicago Press).
Mesulam, M. Marsel (1992). “Brief speculations on frontoparietal interactions and motor autonomy. In Anthony B. Joseph and Robert R. Young (eds.), Movement disorders in neurology and neuropsychiatry (Ch . 89; Cambridge, Mass.: Blackwell Scientific Publications, Inc.), pp. 696-98.
Miller, M. B. and B. L. Bassler. 2001. “Quorum sensing in bacteria.” Annual Review of Microbiololgy (Vol. 55), pp. 165-99.
Morris, Desmond. 1967. The naked ape: A zoologists’s study of the human animal (London: Vintage Books, 2005).
Niu, Ben, Wang, Hong, Duan, Qiqi, and Li Li. 2013. “Biomimicry of quorum sensing using bacterial lifecycle model.” BMC Bioinformatics (Vol. 14, Supplement 8). [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3654883/ (accessed March 30, 2016)]
Pell, M. D., Rothermich, K., Liu, P., Paulmann, S., Seth, S., and S. Rigoulot. 2015. “Preferential decoding of emotion from human non-linguistic vocalizations versus speech prosody.” Biological Psychology (Vol. 111), pp. 14-25. [https://www.mcgill.ca/pell_lab/files/pell_lab/pell_biolpsychology_2015_0.pdf (accessed April 15, 2016)]
Pinker, Steven. 1994. The language instinct (New York: W. Morrow and Co.).
Rosemond, John. 1992. "Bored in toyland." Hemispheres (December), pp. 95-6.
Ruhlen, Merritt. 1994. The origin of language: Tracing the evolution of the mother tongue (New York: John Wiley & Sons).
Scheflen, Albert E. 1965. “Quasi-courtship behavior in psychotherapy. Psychiatry (Vol 28, No. 3), pp. 245-57.
Stilwell, M. Frances and John C. Fentress. 2010. “Grooming, sequencing, and beyond: How it all began.” In Kalueff, Allan V., LaPorte, Justin L., and Carisa L. Bergner (eds.), Neurobiology of Grooming Behavior (New York: Cambridge U. Press), pp. 1-18.
St-Gelais, F., Jomphe, C., and L. E. Trudeau. 2006. “The role of neurotensin in central nervous system pathophysiology: what is the evidence?” Journal of Psychiatry and Neuroscience (July; Vol. 31, No. 4), pp. 229-45.
Stout, Dietrich and Thierry Chaminade. 2011. “Stone tools, language and the brain in human evolution.” Philosophical Transactions of the Royal Society B: Biological Sciences (November; London: Royal Society Publishing). [http://rstb.royalsocietypublishing.org/content/367/1585/75 (accessed March 23, 2016)]
Swadesh, Morris. (1971). The origin and diversification of language (Chicago: Aldine).
Tamir, Diana and Jason P. Mitchel. 2012. “Disclosing information about the self is intrinsically rewarding.” Proceedings of the National Academy of Sciences (Vol. 109, No. 21), pp. 8038-043.
Tanji, J., and K. Shima. 1994. "Role for supplementary motor area cells in planning several movements ahead." Nature (Vol. 371, No. 6496, September 29), pp. 413-16.
Trevarthen, Colwyn. 1997. “Music and Infant Communication.” Nordic Journal of Music Therapy (Vol. 9, No. 2), pp. 3-17.
Young, Malcolm P., and Shigeru Yamane. 1992. "Sparse population coding of faces in the inferotemporal Cortex.” Science (Vol. 256, 29 May), pp. 1327-31.
