Ch.2 LANGUAGE, MIND AND BRAIN

No amount of prodding, training, rewarding or hoping has been able to produce reasonable approximations of human language among any type of animal. And though we have been able to create and program computers that can play chess with the masters, draw beautiful artwork, and solve mathematical problems far too complex for any human, we still are not close to getting the computer to pass an old and simple artificial language test known as the Turing Test.1 Therefore the tentative conclusion has been that true language belongs to humans alone and will not, regardless of technology, be reproducible by any other machine, electrical or biological.2

This conclusion leads many to postulate about the “true" nature of humanity. Is language the one ultimate definer of human-ness? Does the capacity for language automatically allow us to label a thing “human" or more radically, “soulful/mindful"? Though the answers to some of these questions have been debated for many centuries, we are now only slightly closer to answering them philosophically. Scientifically, such questions are moot, so the search for language differences in humans is limited to localizing, predicting, and controlling language capability.

Language and the Brain

There are several areas of the brain important for language production (see Appendix A.4). Broca’s and Wernicke’s, are probably the most famous. Typically the left hemisphere is designated the “language hemisphere" and is said to produce language. Actually, though, both Broca’s and Wernicke’s areas are more active in the left hemisphere, there is right hemisphere activation during language production. This has been explained by the distinction between literal comprehension of words and the emotional comprehension of meaning.

Dysphasics (people who have problems with language) often have lesions in Broca’s or Wernicke’s areas in the left hemisphere (as many as 99% of aphasics have lesions here). In Wernicke’s Aphasia, though they can hear sounds, and may be able to match a sound with a corresponding image (a “meow" with a picture of a cat), they are unable to verbally express a comprehension of the meanings of words. Their production of normal language is impaired, since they are unable to match their “internal listing of words" with the corresponding meanings. They have no problem speaking and using words (i.e., their rhythm, intonations, gestures, and word production is unaffected), but their sentences are merely a nonsense jumble of words, though one would not know it unless one were concentrating on the meaning of the words and phrases themselves. Likewise, they may be unable to understand verbal or written language, via the same process.

Broca’s Aphasics, on the other hand, are better at matching words with their definitions, but cannot produce the words themselves. There is nothing wrong with their motor cortex, because they can repeat words, and make any noise on command, but they cannot produce “words" from internal command. Recently, however, it has been shown that not only is this area activated during speech acts, but also with simple tongue and hand movements, so it is probably important in the coordination of motor programming of language production, rather than “internal" language generation (Liotti 1994:184). These two phenomena (Broca’s and Wernicke’s) typify lesions in the left hemisphere, which is a major center for literal language comprehension.

Right hemispheric temporal lobe lesions, however, rarely impair a person’s ability to communicate literal meanings. These patients may, however, have difficulty grasping the emotive content of the statement, and may have difficulty interpreting “paralanguage" such as gestures, facial expression, and intonations, as they are associated with propositional language. Patients with right hemisphere temporal lobe lesions may have problems appreciating “humor, imagery, visuo-spatial processing, and some aspects of attentional mechanisms" (Segalowitz 1983:110). These patients, though their syntax and word usage is normal, show language impairment similar to patients with cognitive-affective disorders.

Neither of these two areas is significantly activated during “automatic speech" (Friberg 1993:36).3 This indicates that these areas are not necessary when performing simple, rote-memory tasks such as counting to twenty, or reciting days of the week. Other tasks which may not normally be automatic, like repeating the Greek alphabet, can be made to bypass the Broca areas, with only fifteen minutes of practice with some material. Thus that information is eventually put into areas of the brain not having connections to Broca, therefore not requiring Broca to process them. This also indicates that certain types of vocalizations involve different types of mental work, and that just because we are saying something doesn’t mean that our brains are producing a “meaning" (something we have probably all experienced, sometimes with unfortunate consequences).

Two other areas of the brain showing activation during language production are the posterior superior parietal cortex and the posterior inferior temporal cortex. These areas are activated when subjects are asked questions requiring them to remember visual events. For example, when asked “How do you usually spend Christmas Eve," and required to give accurate visual descriptions, these two areas are very active. It is hypothesized that these areas contain visual memories. A third area, related to these two, is the superior prefrontal cortex. This area seems to be an organizational structure which pulls together the visual memories in the other two areas and organizes them with the verbal demands of Broca’s to make an holistic, speakable meaning.

Thus we see that there are a few select areas of the brain implicated in pure language usage, though many areas of the brain come together for language tasks. There are certain areas of the brain that retrieve and store auditory and visual memories, and computational functions, but it is important to realize these are not language processing areas. Language retrieval areas use these memories to synthesize comprehensive and translatable messages, but the areas themselves do not have true language function. As neurobiologists, psychologists, linguists, and philosophers delve deeper into the workings of the brain, it is important to realize what areas to focus on, while being able to weed out related but non-primary brain areas involved with language.

The brain has the capacity to distinguish between visually presented real words, pseudowords, non-words and false-fronts, as well as aurally presented words, clicks and random noises.4 This isn’t new information to us, as we are constantly discriminating these various stimuli, but the processes the brain uses sheds light on our ability to obtain information. The most basic areas that recognize words are the lateral extrastriate which is activated on any letter-like presentation (false-fronts, non-words, pseudowords, and real words), and Heschl’s gyrus and the left posterior middle temporal lobe are activated on any word-like sounds or clicks. At a higher level the posterior superior temporal lobes and the left medial extrastriate area are activated on visual presentation of only words or pseudowords (but not non-words or false-fronts), as well as aural presentation of real or pronounceable words (but not nonsense sounds). If the information gets past this point, it is transferred to the frontal or pre-frontal areas for final processing for conscious understanding (Petersen 1993:519-20; Price 1992:179).

But certain information, it seems, will not be automatically forwarded to these areas. Only words which follow certain pre-learned patterns are given to the frontal areas. One study done by Buchwald examines the Japanese brain when presented with English words containing the sounds /r/ and /l/, which the Japanese language does not contain. Most English speaking Japanese could not discriminate between “rip" and “lip," because the neurons in their brains which would process these sounds have not been trained, and are not active (Buchwald 1994:614). Likewise, neither could many of the Japanese speakers pronounce these letters without extensive training, and some never became proficient at either discriminating or pronouncing them.

Only in the last decade have the frontal and pre-frontal areas become implicated in language function. Using simple, yet ingenious psychological testing, combined with brain imaging techniques (MRI, PET, CAT, etc.), we can literally see areas of the brain used for various tasks. Though we had previously been able to localize such areas as Broca’s using more rudimentary techniques, the new methods have enabled us to see comprehensively and almost instantaneously what is happening in the brain.

It appears that “neuronal speech programs are ‘housed’ in the prefrontal regions and are used as templates in word identification during perception" (Ingvar 1993:246). Pay close attention to notice that it is being hypothesized here that at some level there are “programs" in the brain that lay the foundation for language, and that these programs appear to be placed there genetically. It seems that “working memory" function is located in the left pre-frontal cortex. More global, well-learned language functions and prosody are located in the right prefrontal cortex.5 “Value" related and emotional aspects of language are found in the mesial cingulate prefrontal cortex. These prefrontal areas are activated whenever novel responses are required (Petersen 1993:525), and the need arises to associate one word with another (to store or retrieve the memory that “fast" is associated with “cheetah," or “Maserati") (Liotti 1994:185). They are activated when retrieval strategies and planning activity are required (Grasby 1993:5). Frontal areas store “verb lists," and left prefrontal areas store “noun lists." Further, “there are cells in the left prefrontal cortex which respond selectively to the nouns that are not objects . . . and do not respond to nouns that are concrete objects" (Abdullaev 1993:175), different areas that respond to action verbs versus transitive verbs, etc. Striking examples of these “word class areas" are found in patients with localized brain damage. Patients have problems naming only certain classes of objects, such as nouns associated with music (flute, piano, song), animal words, or nouns associated with metallic objects.

Another area of the brain important when studying the mind is the frontal cortex. It seems that semantic coding takes place here. Imaging techniques and lesion studies support the idea that “higher-order semantic and grammatic codes of language are processed by the cells in the left anterior frontal cortex of the human brain" (Abdullaev 1993:175). Lesions of this area produce impairment of fluency, normal articulation and phonological production. The neurons in this area show no response to simple visual naming or word recognition tasks, but are significantly activated when the subject is required to form semantic verb-noun association tasks. If this hypothesis is true, it would be important for psycholinguists who feel humans have the innate capacity for language because of some structural endowment in the brain, rather than merely as a function of environmental learning.

To summarize, there are only a few areas of the brain specifically designated for language function. Motor areas are the most primitive, and control word producing muscles in the throat. Memory areas are also secondary type areas, since they do not actually produce or mediate the language production process, but merely form the basis for certain types of recitations. The three areas of prime importance are the frontal and prefrontal areas, and the temporal gyrus. The prefrontal area is important in organizing complex thoughts, producing novel responses to situations, and acts as a storehouse for “speech programs" and nouns. The frontal area is important for higher-order semantic processing of words and phrases, and stores verbs. The temporal gyrus (Broca’s and Wernicke’s areas) are important in matching definitions of words with the “word lists." Together these three areas, along with the many other areas of the brain, work to give us language as we know it, in its richness, generativity, and power.

Language and Animals

What does it mean to be human? What does it mean to be mind-ful? Do animals have souls? Each of these questions is ancient and scientifically unanswerable. But recently science has been attempting to answer questions like these. Psychologists, anthropologists and neurobiologists have been trying to define what differentiates humans from all other animals, if there is anything that differentiates us. In the past few decades there has been a seeming consensus that language is a major, if not the only difference between humans and each of the other animal species. Because of the important role language has come to play in philosophy, psychology, and other fields, specialties have arisen to deal with only language (e.g., neurolinguistics, psycholinguists, philosophers of language, etc.).

How do we know, and what can we know a priori? These epistemological questions may finally have some kind of answer (at least from a naturalistic, scientific perspective) in the study of neurolinguistics. With the discovery of certain brain areas that “control language" in the abstract, localization of concrete and non-concrete “noun lists," definition matchers, semantic processors, and novel idea producers, we are much closer to being able to localize Descartes’ “human center" (for him it was the pineal gland). This is based on the assumption (propagated by Descartes himself) that human language is unique among all animals and defines who we are as humans.

Three good reviews of this idea that human language is unique are found in Michael Corballis (1992), Jean Aitchison (1983) and Mortimer Adler (1967). Corballis mentions the consensus that “even our closest living non-human relative, the chimpanzee" has no language capacity (1992:199). He goes on the say that even though “chimpanzees can use arbitrary tokens in symbolic fashion, and can use them to refer to objects or events remote in space or time . . . even so, it has been seriously questioned whether these data imply that apes can use symbols in a genuinely linguistic fashion, in the way that children do."

One evidence for this is the generativity of human language (Corballis assigns this proposition to Chomsky). He says “two critical ingredients of generativity are a vocabulary of units and rules for combining them" (1992:200). These rules allow us to make any combination of novel phrases to describe any given meaning, while also allowing us to recognize improper formations of phrases. This generativity is important because of its practical infinitude of possibilities.

To achieve this level of generativity requires that rules be applied recursively; that is, a given rule can be applied to its own output, or to the output of other rules, repeatedly and without any limit save that imposed by the processing capacity of the individual. For example, phrases can be embedded in other phrases to produce sentences of any desired level of complexity. (Corballis 1992:200)

Corballis contends that the research indicates no attempts to teach artificial languages to non-humans have been able to produce generativity or recursiveness, and certainly not the spontaneous, conversational aspect of human language we all take for granted. An important point to note is that even though “the general cognitive abilities of apes are in many respects comparable to those of a human child . . . their linguistic ability is by contrast rudimentary" (1992:201).

Aitchison, a linguist, attempts to define language in a comprehensive way, while at the same time avoiding tautology. She relies on the work of Charles Hockett, and expounds on a few of his characteristics important for human-animal distinctions. The first distinction is arbitrariness. The use of arbitrary symbols to represent concrete objects (e.g. un chien, ein hund, or canis and rhodon are all equally satisfactory, arbitrary names for “dog") might seem to be unique to human language, but, for example, sea gulls “indicate aggression by turning away from their opponent and uprooting beakfuls of grass" (both arbitrary “symbols" for aggression; Aitchison 1983:37). Another possible distinction is semanticity. Humans can say “chair" and generalize many possibilities for this word, but all will be relatively similar, and all will probably be correct. But a vervet monkey (Cheney 1990) “might or might not mean ‘snake’ when he chutters" (Aitchison 1983:37).

The next two possible distinctions between humans and animals are spontaneity and turn-taking, which might intuitively seem unique to humans. What, for example, would a lower animal have to communicate if not survival-type messages (therefore non-spontaneous), and what is turn-taking behavior except “courtesy." Unfortunately, though, neither of these two characteristics is uniquely human, since many animals vocalize spontaneously (for no apparent reason), and birds will commonly take turns singing phrases of their songs (1983:38). A fifth possibility is cultural transmission. This possibility is slightly more viable. Bird songs, for example, are basically genetically innate, but the finer points of the songs are learned. Similarly, vervet vocalizations are innate and recognizable by other vervets without prior training (Cheney 1990). Humans, however, have no recognizable language without training.

A sixth possible distinction is displacement. Very few examples can be produced of animals communicating about objects or events not in their immediate environment. Even bees, who describe nectar patches miles away so other bees can find it, still cannot express “The day before yesterday we visited a lovely clump of flowers, let’s go and see if they are still there" (Aitchison 1983:39). This characteristic seems to be a very viable possibility, according to Aitchison. Another viable characteristic is structure-dependence. We have no examples or models of animals using deep-structure when communicating. “Humans do not just apply simple recognition or counting techniques when they speak to one another" (1983:39), but will “automatically recognize the patterned nature of language, and manipulate ‘structured chunks.’" Finally, Aitchison concludes her list with what appears to her to be the most important of all possible characteristics, creativity. This she derives from Chomsky, and is similar to Corballis’s generativity, which has already been described earlier in this paper.

Aitchison ends her discussion of animal-human distinctions by looking at the most complex of all “animal" communication, the gorilla and chimpanzee studies done on Koko and Nim Chimpsky. She devotes many pages to building up the case of the great intelligence of these two animals (Koko is reported to have an underestimated IQ of 85-95 based on the Stanford-Binet), and the many language-like features they showed in their communication (possible creativity, arbitrary symbols and semanticity, displacement, etc.). But she concludes by doubting their true language capability (1983:57-58).

They have a grasp of some design characteristics of language which hitherto had been regarded as specifically human. However, their ability does not extend much further. The caged animals can carry out simple slot filling manoeuvres [sic], providing they are adequately rewarded. The naturalistically trained ones show no evidence of structure, they merely display a preference for placing certain signs first or last in a sequence. Chomsky may be right, therefore, when he points out that the higher apes ‘apparently lack the capacity to develop even the rudiments of the computational structure of human language.’ . . .

Note finally that even though intelligent animals seem capable of coping with some of the rudimentary characteristics of human language, they do not seem predisposed to cope with them. The situation is parallel to that found among birds. Some birds are able to learn the songs of a different species. But they find the task a difficult one. When the birds are removed from the alien species, and placed among their own kind, they learn their normal song with extreme rapidity. . . . The apparent ease with which humans acquire language, compared with apes, supports the suggestion that they are innately programmed to do so.

A final note on animal studies can be brought out by Cheney in her studies of vervet monkeys. In addition to some of the characteristics mentioned above, she expounds on two other aspects of human and animal communication. First, humans seem to have at least second order intention, whereas animals don’t seem to have any more than first order intention (the idea of intentionality is further explained by Dennett 1987). Briefly, animals at times seem to show behavior indicating they believe other animals have beliefs, while a human A seems to be able to believe another person B has beliefs about person A’s beliefs, ad infinitum. Secondly, humans have the ability to generalize knowledge gained from certain experiences to other, non-related experiences. For example, say a mailman saw a dog foaming at the mouth and acting aggressively and later found out the dog had rabies. If, at a later time, that same man saw a cat, or even another human exhibiting those same symptoms, he would be able to make the reasonable assumption that that cat or human was also suffering from rabies. Animals do not share this ability to generalize cognitive experiences.

Mortimer Adler, a philosopher, also supports these conclusions. He discusses human distinctiveness in The Difference of Man and the Difference it Makes. While he also makes a list of attributes he believes distinguish humans from other animals (technological capacity, transmission of cultural traditions, and political, religious, ethical and aesthetic propensities), he focuses on language to argue that humans are radically different in kind from animals. He interacts with authors who equate the capacity for propositional language with personhood, and says that if animals or machines were to gain such skills, they too must then be considered persons (Adler 1967:263). He distinguishes between differences in kind and in degree (the difference between a tiger and a cougar is in degree, while the difference between a tiger and an eagle is in kind), and further distinguishes between superficial and radical differences in kind (the difference between a tiger and an eagle is superficial, while the difference between a tiger and a chair is radical).

Adler goes to great lengths to show how humans and animals are different in kind, while presenting various evidences which he admits do not allow us to yet determine whether we are superficially or radically different. He claims that if species evolution is correct, then we must be only superficially different since our linguistic capabilities are the result of shifts in our neurological structure (Adler 1967:126). He continues by examining the consequences of such a view, and by discussing the various implications of the options, topics which we will examine in greater detail in Chapter Six.

Conclusion

We can use the animal and neural data to help put some limitations on mind. We know from neural/psychological studies the human brain uses past experiences to guide language production. The brain itself distinguishes real words from pseudowords and from nonsense letter strings, and discards much of the information before it reaches the consciousness, so we know there are automatic, biological limiters of what we know. Since our brain filters what we process, we are at least aware of the possibility there are things we perceive but will never realize or integrate (because of our innate anatomical structure). This doesn’t mean we can necessarily never perceive them, because many motor reflexes (such as the knee jerk reflex, also controlled by the brain) can be over-ruled by conscious effort, but we still must leave open the possibility of innate limits. We also know organizing information into patterns is important, since the brain devotes significant structures to this task. Finally, we know we have structures devoted to novel and creative aspects of language, not related to general problem solving areas.

There are seven characteristics which seem like excellent candidates for describing the unique properties of the human mind. From animal studies we realize that the generativity and open-endedness of human language are unique to humans, therefore they are good candidates for mind, as is the spontaneous, conversational aspect of language. Two lesser candidates (but not insignificant) are the learned requirement of human language whereas most animal phonemes are biologically pre-programmed, as well as the ability of humans to talk about displaced objects, in both time and space. Two more important possibilities for characteristics of mind are creativity and deep-structure.

The deep-structure aspect hearkens back to Noam Chomsky, when he postulates an area of the brain which contains a pattern for a universal grammar. Though there have been thousands of languages throughout history, all of them, as far as we can tell, have the same basic pattern of noun-verb association, among other various linguistic patterns. These patterns, according to Chomsky, are the foundations for a universal grammar. This grammar would most likely be based on genetically determined anatomical structures, which are extremely similar in all humans.6 This anatomical correlation makes language possible, and controls how the person expresses thought (or conversely, controls how the person can think). Neural data support this hypothesis. This deep-structure to all language depends on the universal grammar and allows communication to occur, and recognition of inaccurate formations of phrases.

Finally, intentionality and generalizability are also likely candidates for characteristics of the human mind. These two, along with the other characteristics, give us a good foundation for describing mind, and possibly the ability to limit what mind can know and what it knows a priori.

The study of mind is just now coming of age in the scientific world. While some previously thought that the mind could be viewed as merely excretions from brain like urine is excreted from the kidneys, mind is now coming to be thought of as a real, and empirically observable entity. The medium that seems most appropriate to study the phenomenon of mind is language. The case has already been made that language is a phenomenon mostly unique to humans. Based on this assumption we are left a wonderful tool for studying the mind.


Footnotes

1. The Turing Test (Alan Turing, “Computing Machinery and Intelligence," Mind 59 (1950):433-460) is a classic test proposed by Alan Turing in 1950 which was designed to tell if a subject has a “mind." The test was to have person “A" communicate through a computer terminal to the subject “B." “A" could ask any questions he wanted, or make any statement, and “B" simply had to use appropriate language skills to continue the dialogue with “A." If “A" could not tell if “B" was an human or a computer, then “B" would be deemed to have a mind. This test, used as the standard to test computers for mind, assumes that the presence of normal language would necessarily imply the presence of mind.

2. Note here that the term “language" specifically refers to normal human language, which includes all spoken, written and formal gestured language (sign language). Though other species have the capacity to “communicate," neither other animals, nor computers have the capacity (yet) to use true “language."

3. In this case, automatic speech refers to tasks requiring rote memory, such as reciting the alphabet, spellling one’s own name, reciting the basic addition or multiplication tables, etc. Almost any short list or table can become automatic if repeated enough, and over a sufficient period of time. Tasks such as spelling infrequently used, or long words, or giving directions to some city or landmark are not “automatic" and typically require the use of specific thought process in addition to pure memory.

4. Pseudowords are words which follow normal spelling rules, but which are not actually words (e.g., “tweal"). Non-words are simply strings of letters (lshfuih). False-fronts are characters which have the shape of letters, but aren’t. The fact that the brain shows unique activation to false-fronts as well as to the regular alphabet shows there are special areas which recognize letter, but that area has flexibility with its recognition system. Thus we are able to discern handwritten and typed letters of radically different styles!

5. Working memory refers to the information that is currently “running around in your head." The global, well-learned language functions refer to the grammar and syntax we learn from our culture that gives us the “way to say" what is “in our heads." These global functions conform to the inherent patterns provided genetically by our brains. An analogy is a newly built building. First the foundation and frame of the building are built, then they are “filled in" with walls and windows and such to give the building its final form. Finally the inhabitants of the building bring in chairs, pictures, office or living supplies, etc. Similarly, the brain is “laid out" initially (genetically) with certain grammar accepting areas. This learned grammar and syntax is like the walls and windows. The actual words that are learned are like inhabitants of the building that give the building its character and usability. Prosody is features such as “pitch, loudness, timber, tempo, stress, accent, pauses, intonation and melody" (Liotti 1994:184).

6. Note that recent philosophical trends have rejected Chomsky’s universal grammar, and have opted for a more chaotic structure for language. This kind of “armchair philosophizing" can certainly play a part in the development of scientific hypotheses, which can then either be proven or disproven. It appears, at this point, however, that Chomsky’s vision of a universal grammar has been the theory that has physical support, and not the anti-foundationalists (Behavioralists). Besides the studies already mentioned that support the idea that the brain is not a Tabula Rasa, developmental neurobiology (the study of how the brain initially organizes itself into a working, high-functioning organism) shows us very specific paths the brain takes as it first grows and interconnects the different areas with one another, rather than a random growing with every structure connected to everything else. The consensus seems to be that the brain is designed to receive and process data, and certain types of data at that.