Unequaled Communication Skills

Other parts of the brain also contribute to our uniqueness. Behind our prefrontal cortex is a strip stretching across the head—the motor cortex. It contains billions of neurons that connect with our muscles. It too has features that contribute to our being far different from apes or other animals. The primary motor cortex gives us “(1) an exceptional capability to use the hand, the fingers, and the thumb to perform highly dexterous manual tasks, and (2) use of the mouth, lips, tongue, and facial muscles to talk.”—Guyton’s Textbook of Medical Physiology.

Consider briefly how the motor cortex affects your ability to speak. Over half of it is devoted to the organs of communication. This helps to explain the unparalleled communication skills of humans. Though our hands play a role in communication (in writing, normal gestures, or sign language), the mouth usually plays the major part. Human speech—from a baby’s first word to the voice of an elderly person—is unquestionably a marvel. Some 100 muscles in the tongue, lips, jaw, throat, and chest cooperate to produce countless sounds. Note this contrast: One brain cell can direct 2,000 fibers of an athlete’s calf muscle, but brain cells for the voice box may concentrate on only 2 or 3 muscle fibers. Does that not suggest that our brain is specially equipped for communication?

Each short phrase that you utter requires a specific pattern of muscular movements. The meaning of a single expression can change depending upon the degree of movement and split-second timing of scores of different muscles. “At a comfortable rate,” explains speech expert Dr. William H. Perkins, “we utter about 14 sounds per second. That’s twice as fast as we can control our tongue, lips, jaw or any other parts of our speech mechanism when we move them separately. But put them all together for speech and they work the way fingers of expert typists and concert pianists do. Their movements overlap in a symphony of exquisite timing.”

The actual information needed to ask the simple question, “How are you today?” is stored in a part of your brain’s frontal lobe called Broca’s area, which some consider to be your speech center. Nobel laureate neuroscientist Sir John Eccles wrote: “No area corresponding to the . . . speech area of Broca has been recognized in apes.” Even if some similar areas are found in animals, the fact is that scientists cannot get apes to produce more than a few crude speech sounds. You, though, can produce complicated language. To do so, you put words together according to the grammar of your language. Broca’s area helps you do that, both in speaking and in writing.

Of course, you cannot exercise the miracle of speech unless you know at least one language and understand what its words mean. This involves another special part of your brain, known as Wernicke’s area. Here, billions of neurons discern the meaning of spoken or written words. Wernicke’s area helps you to make sense of statements and to comprehend what you hear or read; thus you can learn information and can respond sensibly.

There is even more to your fluent speech. To illustrate: A verbal “Hello” can convey a host of meanings. Your tone of voice reflects whether you are happy, excited, bored, rushed, annoyed, sad, or frightened, and it may even reveal degrees of those emotional states. Another area of your brain supplies information for the emotional part of speech. So, various parts of your brain come into play when you communicate.

Chimpanzees have been taught some limited sign language, but their use of it is essentially limited to simple requests for food or other basics. Having worked to teach chimps simple nonverbal communication, Dr. David Premack concluded: “Human language is an embarrassment for evolutionary theory because it is vastly more powerful than one can account for.”

We might ponder: ‘Why do humans have this marvelous skill to communicate thoughts and feelings, to inquire and to respond?’ The Encyclopedia of Language and Linguistics states that “[human] speech is special” and admits that “the search for precursors in animal communication does not help much in bridging the enormous gap that separates language and speech from nonhuman behaviors.” Professor Ludwig Koehler summarized the difference: “Human speech is a secret; it is a divine gift, a miracle.”

What a difference there is between an ape’s use of signs and the complex language ability of children! Sir John Eccles referred to what most of us have also observed, an ability “exhibited even by 3-year-old children with their torrent of questions in their desire to understand their world.” He added: “By contrast, apes do not ask questions.” Yes, only humans form questions, including questions about the meaning of life.

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Language and Intelligence

Why does human intelligence far surpass that of animals, such as apes? A key is our use of syntax—putting sounds together to make words and using words to make sentences. Theoretical neurophysiologist Dr. William H. Calvin explains:

“Wild chimpanzees use about three dozen different vocalizations to convey about three dozen different meanings. They may repeat a sound to intensify its meaning, but they do not string together three sounds to add a new word to their vocabulary.

“We humans also use about three dozen vocalizations, called phonemes. Yet only their combinations have content: we string together meaningless sounds to make meaningful words.” Dr. Calvin noted that “no one has yet explained” the leap from the animals’ “one sound/one meaning” to our uniquely human capacity to use syntax.