MONKEY TALK : Language – a human monopoly or a communal property with the animal kingdom – a Psycholinguistic study

by

Adnan Firoze

Abstract              

In this paper I present a comparative and contrastive study between human and animal language from the standpoint of Psycholinguistics. Human language itself is one of the very features that distinguish its own kind from the rest of the animal kingdom. However, language is just one of the features that declare our supremacy over other kinds. The uniqueness of human language has its very own aspects as well and they have been covered in my paper in detail. In addition to production and comprehension of language, the psycholinguistic aspects of more complex tasks such as reading and writing have been covered as well. Moreover, it would be a fallacy to have a dogmatic ideology that humans are the only beings with language or any means that may resemble what we perceive as language. Animals, too, exhibit communicative features and some of them are surprisingly similar to that of humans. Therefore, the concept that animals do not have any form of language has been rejected by scientists and psycholinguists. My paper analyzes several “case studies” on animal languages (mostly on chimpanzees) and the progresses of them. Finally, I analyze the phenomenon known as “language” of both humans and animals from the reference of psycholinguistics – the study of the relationship of language and the mind along with my own interpretation of the viability of the current studies in this specific field. The novel feature of me paper is that it does not only concentrate on human brain but it analyzes the language processing of animal brains as well.

Introduction

“Language is a unique disposition of man” – was the initial ideology stemming from the Biblical times. However, human languages are not the only breed of languages on Earth just like humans are not alone on the face of the Earth. The world contains more than 7000 species and almost all of them have communicative means. Then again, “language” as a term has been given a special prestige by issuing it exclusively to humans; but this is a very narrow approach of looking at language. If the communication of animals are simply rejected from the paradigm of “language” then that would be dogmatic and unacceptable to all schools of sciences and philosophy. Then again, there are indeed distinction between human language and animal language (which some prefer to call “animal communication”).

However, human language is not as “automatic” as one may seem to think naturally. The human brain goes through a number of complex processes utilizing several of its “language centers” in production and comprehension of language. On the flip side, animals also go through complex mental processes in their own form of communication. The realm of both the studies fall under the umbrella term of “Psycholinguistics” and both are covered in later chapters.

Moreover, upon finishing the case studies, I inferred that the “Innatism Hypothesis” of Noam Chomsky has been questioned to be exclusive for humans or not. This is one of the most burning questions that have bewildered psycholinguists. After reviewing all the studies presented later in the paper, in my opinion, the Language Acquisition Device (LAD) is not an exclusive predisposition of man but some other species exhibit such innate gifts as well.

 

Uniqueness of Human Language

There are several aspects of human language that are unique. In order to fully comprehend the similarities and contrasts of human and animal language, it is imperative to introduce and elucidate the certain aspects of language that are exclusive to humans. One of the very intuitive examples is the idea of creativity. We can come up with fiction and we can also lie but animals cannot. However, beyond this intuitive aspect lie some formal unique properties which are elaborated below.

  1. Displacement: This unique property of human language refers to the existence of “tense.” We are able to recall past experiences and predict about future in our discourse however animals are stuck in the present. If a dog comes up and barks then the obvious understanding is that the dog is relating the bark (as an expression of discomfort or any other message) to that immediate time and place. However, the dog cannot convey what his actions were two days back because they will still encode the message as a bark. One important aspect here is the fact that we need to acknowledge that even though we are taking displacement as unique to us, it so may be that the past tense of the dog are not being able to be decoded by humans. The property of human language that they can refer to past and future time is called displacement. It allows language users to talk about things and events not present in the immediate environment. Moreover “fiction” is considered under “displacement” as well.

An important aspect to note is that some animals show “some” degree of “displacement” (Yule, 1999).  It has been proposed that bees have some attributes of displacement in their communication. For example, when a worker bee finds a source of nectar and returns to the bee hive, it can perform a complex dance to communicate to the other bees the location of this nectar. Depending on the type of dance the other bees can work out where this newly discovered food source is. This phenomenon exhibits some degree of “displacement” in bees.  Bee communication has displacement in an extremely limited form.

  1. Arbitrariness: This property refers to the fact that there is no one to one connection between the signified and signified in human language.  The connection is quite arbitrary. In other words, the linguistic form of the word “dog” has no natural or ‘iconic’ relationship with that hairy four-legged barking animal. This aspect of the relationship between linguistic signs and objects in the world is described as arbitrariness. However onomatopoeic words such as cuckoo, CRASH, slurp, squelch etc. that echo actual noises are exceptions to this property.
  2. Creativity: Unlike animals, we are able to continually create new expressions and novel utterances by manipulating our linguistic resources to describe new objects and situations. This property is described as “creativity” or “productivity”. A very good example was set forth by Yule (1999) where he mentions “Each signal in the animal language system is fixed as relating to a particular object or occasion. Among the vervet monkey’s repertoire, there is one danger signal CHUTTER, which is used when a snake is around, and another RRAUP, used when an eagle is spotted nearby. These signals are fixed in terms of their reference and cannot be manipulated. What might count as evidence of productivity in the monkey’s communication system would be an utterance of something like CHUTT-RRAUP when a flying creature that looked like a snake came by. Despite a lot of experiments involving snakes suddenly appearing in the air above them (among other unusual and terrifying experiences), the vervet monkeys didn’t produce a new danger signal. The human, given similar circumstances, is quite capable of creating a ‘new’ signal, after initial surprise perhaps, by saying something never said before, as in Hey! Watch out for that flying snake!
  3. Cultural Transmission: Cultural transmission is the process by which a language is passed on from one generation to the next. It is clear that humans are born with some kind of predisposition to acquire language in a general sense. However, we are not born with the ability to produce utterances in a specific language such as Bangla or English. We acquire our first language as children in a culture. The general pattern in animal communication is that creatures are born with a set of specific signals that are produced instinctively. In contrast, a dog born in Bangladesh will bark in the similar manner as it will in USA.
  4. Duality: Human language is organized at two levels simultaneously. This property is called “duality”. In speech production, humans have a physical level at which we can produce individual sounds, like /t/, /p/ and /i/. As individual sounds, none of these discrete forms has any intrinsic meaning. In a particular combination such as “tip”, there is another level producing a meaning that is different from the meaning of the combination in “pit” (since the same sounds make up “tip” and “pit”). So, at one level, there are distinct sounds, and, at another level, there are distinct meanings. This duality of levels is, in fact, one of the most economical features of human language because, with a limited set of discrete sounds, we are capable of producing a very large number of sound combinations (e.g. words) which are distinct in meaning. In contrast if a dog expresses anger by saying /GRR/ it will not be able to express happiness by reversing the sound as /RRG/.

These are the aspects that make human language distinct from animal languages. However, in my personal finding and observations, there are many similarities between the two as well. Moreover, the mental processes are very relevant in order to comprehensively suggest a study a psycholinguistic approach to understanding human and animal language.

The Psycholinguistics Processes of Human Language Processing (as basic rudiment)

The process of identifying the parts of the brain that are involved in language began in 1861, when Paul Broca, a French neurosurgeon, examined the brain of a recently deceased patient who had an unusual disorder. Though he had been able to understand spoken language and did not have any motor impairments of the mouth or tongue that might have affected his ability to speak, he could neither speak a complete sentence nor express his thoughts in writing. The only sound he could make was the syllable “tan”, which had come to be used as his name (McGill Online, 2011). When Broca autopsied Tan’s brain, he found a sizable lesion in the left inferior frontal cortex. This led him to make his famous statement that “we speak with the left hemisphere” and to identify, for the first time, the existence of a “language centre” in the posterior portion of the frontal lobe of this hemisphere. Now known as Broca’s area, this was in fact the first area of the brain to be associated with a specific function—in this case, language.


Ten years later, Carl Wernicke (1871), a German neurologist, discovered another part of the brain, this one involved in understanding language, in the posterior portion of the left temporal lobe. People who had a lesion at this location could speak, but their speech was often incoherent and made no sense.

Wernicke’s observations have been confirmed many times since. Neuroscientists now agree that running around the lateral sulcus (also known as the fissure of Sylvius) in the left hemisphere of the brain, there is a sort of neural loop that is involved both in understanding and in producing spoken language. At the frontal end of this loop lies Broca’s area, which is usually associated with the production of language, or language outputs . At the other end (more specifically, in the superior posterior temporal lobe), lies Wernicke’s area, which is associated with the processing of words that we hear being spoken, or language inputs. Broca’s area and Wernicke’s area are connected by a large bundle of nerve fibers called the arcuate fasciculus. This language loop is found in the left hemisphere in about 90% of right-handed persons and 70% of left-handed persons, language being one of the functions that is performed asymmetrically in the brain. Surprisingly, this loop is also found at the same location in deaf persons who use sign language. This loop would therefore not appear to be specific to heard or spoken language, but rather to be more broadly associated with whatever the individual’s primary language modality happens to be.

Fig. The Language Centers of the human brain

In addition to Broca’s and Wernicke’s areas, a third area of importance for language, located in the temporal cortex, has been described more recently which is “Angular Gyrus” and this leads to the next section. It should be noted that “Angular Gyrus” is responsible for concerting sound signals to visual stimuli and vice versa – making it essential in reading and writing.

Production, Comprehension and Complex language tasks (Writing and Reading) Models

A first model of the general organization of language functions in the brain was proposed by American neurologist Norman Geschwind in the 1960s and 1970s. This “connectionist” model drew on the lesion studies done by Wernicke and his successors and is now known as the Geschwind-Wernicke model (Gleason & Ratner, 1997). According to this model, each of the various characteristics of language (perception, comprehension, production, etc.) is managed by a distinct functional module in the brain, and each of these modules is linked to the others by a very specific set of serial connections. The central hypothesis of this model is that language disorders arise from breakdowns in this network of connections between these modules.

According to this model, when someone hears a word spoken, this auditory signal is processed first in the brain’s primary auditory cortex, which then sends it on to the neighboring Wernicke’s area. Wernicke’s area associates the structure of this signal with the representation of a word stored in the individual’s memory, thus enabling him/her to retrieve the meaning of the particular word.

In contrast, when someone reads a word out loud, the information is perceived first by the hearer’s visual cortex, which then transfers it to the angular gyrus, from which it is sent on to Wernicke’s area.

Whether one hears someone else speak a word or read the word himself/herself, it is the mental lexicon in Wernicke’s area that recognizes this word and correctly interprets it according to the context. For the listener then to pronounce this word, this information must be transmitted via the arcuate fasciculus to a destination in Broca’s area, which plans the pronunciation process. Lastly, this information is routed to the motor cortex, which controls the muscles that you use to pronounce the word.

Reading:  Now to demonstrate the processes of Reading the following steps are numerated to simplify the illustration of the process:

  1. The eyes receive visual input and sends to the visual cortex.
  2. Visual cortex transfers the stimuli to the Angular Gyrus.
  3. The visual stimuli is converted to speech by the Angular Gyrus and sent to the Wernicke’s are for comprehension.
  4. If the text is to be read aloud then it is sent to the Broca’s area and finally the motor cortex for articulation

Writing: Writing is almost similar to reading but the steps differ in sequence:

  1. Words are drawn from the Wernicke’s area and sent to Broca’s area for structuring.
  2. Upon completion of text organization the message is sent to the Angular Gyrus which gives the individual a visual representation of his speech.
  3. The visual stimulation then is sent from the Angular Gyrus to the motor cortex to be written by the hand.

The Wernicke-Geschwind model is thus based on the anatomical location of areas of the brain that have distinct functions. On the whole, this model provides a good understanding of the primary language disorders, such as Broca’s aphasia or Wernicke’s aphasia. But it also has its limitations. For one thing, its assumption that the various areas involved in processing speech are connected in series implies that one step must be completed before the next one can begin, which is not always actually the case. Because this model also failed to explain certain partial language disorders, other models had been proposed to address these shortcomings.

Thus in my opinion, the complex tasks involving language are still rather obscure to the scientists even though they have established certain models based on Wernicke’s and Broca’s areas and other language centers. However, none of these approached are absolute in their conclusions. Therefore, the understanding of our own brain has become out last frontier.

Animal Language and Psycholinguistics Applied on Animals

Among all the animals, the chimpanzees or apes have attracted most attention regarding language processing researches. The rationale is quite intuitive as well – they demonstrate much similarity to humans. Science Daily (2008) argued that Chimpanzee communicative behavior shares many characteristics with human language as said by Jared Taglialatela of the Yerkes National Primate Research Center. Results from several studies suggested that these similarities extend to the way in which human brains produce and process communicative signals. Studies also suggest that the “neurobiological foundations” of human language may have been present in the common ancestor of modern humans and chimpanzees.

Scientists had identified Broca’s area, located in part of the human brain known as the inferior frontal gyrus (IFG), as one of several critical regions that light up with activity when people plan to say something and when they actually talk or sign. Anatomically, Broca’s area is most often larger on the left side of the brain, and imaging studies in humans had shown left-leaning patterns of brain activation during language-related tasks, the researchers said.

In a new study, the researchers non-invasively scanned the brains of three chimpanzees as they gestured and called to a person in request for food that was out of their reach. Those chimps showed activation in the brain region corresponding to Broca’s area and in other areas involved in complex motor planning and action in humans. (Science Daily, 2008).

Fig: Broca’s area found in chimpanzees

A study by Cantalupo and Hopkin’s (2001) has shown the existence of Broca’s area in chimpanzees. In their study they show that there is a similar asymmetry in the language processing area of the brain and exhibition of left-hemisphere dominance, in three great ape species (Pan troglodytes, Pan paniscus and Gorilla gorilla). Their findings suggest that the neuroanatomical substrates for left-hemisphere dominance in speech production were evident at least five million years ago and are not unique to hominid evolution. No researched before the one conducted by Cantalupo and Hopkin’s (2001) had assessed whether there is any consistent left–right anatomical asymmetry in the inferior frontal gyrus (IFG) of any non-human primate.

From magnetic resonance images (MRI) obtained from 20 chimpanzees (P. troglodytes), 5 bonobos (P. paniscus) and 2 gorillas (G. gorilla), they found that area 44 (technical term for the area that is known as Broca’s area) in these species shows a pattern of morphological asymmetry that has left-hemisphere surface-area predominance similar to the homologous cortical area of humans. In humans, this region is part of Broca’s area, a key anatomical substrate for speech functions, particularly in motor aspects of speech such as articulation and fluency.


Case Studies on Several Animals regarding Language Production and Comprehension

Since the family of Chimpanzees resemble humans the closest in terms of anatomy and intellectual growth, most of the psycholinguistic studies have taken place on the Chimpanzee family of animals.  It should be noted that, since the chimpanzee family lacks the physical facilities (vocal organs) similar to that of humans, most of the researches were based on sign languages. However, these sign languages have all the essential properties of human language and are learned by many congenitally deaf children as their natural first language. Some of the most successful and well known of such studies are presented below:

  1. Koko: Koko is a female western lowland gorilla who was taught an enormous volume of sign language signs by her master and researcher Francine “Penny” Patterson. Koko was born in 1971 in San Francisco Zoo. She is able to understand more than 1,000 signs based on American Sign Language and understand approximately 2,000 words of spoken English (Wikipedia, 2011). As with other ape language experiments, the degree to which Koko masters these signs has been controversial, as has been the degree to which such mastery demonstrates language abilities.

From her experiments she demonstrated very good comprehension skills just like human infants. It is to be noted that human in fact comprehension supersedes their production and Koko showed similar attributes.

A very interesting story from Koko’s life is to be able to chat with her fans over the internet using sign language. On April 12, 1998 the online chat with Koko took place on America Online (AOL). The transcript of this event, available on many locations on the Internet, contains at least one instance of Koko making a statement resembling a sentence: “Lips fake candy give me”; uttered while Koko was trying to get Patterson to give her a treat. The last three words would constitute the use of an imperative verb accompanied by both a direct and an indirect object. It should be noted, however, that Koko did try a few other, seemingly random, signs translated as “words” before and after this “utterance”, seemingly in order to achieve the same goal – obtaining a treat from Patterson. It has also been noted that Koko does not clearly seem to understand any language being directed to her in the transcript. Nevertheless, “candy give me” may be evidence that Koko can form a sentence (Patterson, 1978).

Koko seems to present a significant epitome of animal language “competence” as well as animal language “performance”.

  1. Washoe:  The second case study that is going to be presented is of a female chimpanzee named Washoe. Since a chimpanzee is a poor candidate for spoken language learning (as they anatomically lack the vocal organs of humans), the scientist couple (Beatrix and Allen Gardner) taught Washoe to use a version of American Sign Language. From the beginning, the Gardners and their research assistants raised Washoe like a human child in a comfortable domestic environment. Sign language was always used when Washoe was around and she was encouraged to use signs, even her own incomplete ‘baby-versions’ of the signs used by adults. In a period of three and a half years, Washoe came to use signs for more than a hundred words, ranging from airplane, baby and banana through to window, woman and you. Even more impressive was Washoe’s ability to take these forms and combine them to produce ‘sentences’ of the type “gimme tickle”, “more fruit” and “open food drink” (to get someone to open the refrigerator). Some of the forms appear to have been inventions by Washoe, as in her novel sign for bib and in the combination water bird (referring to a swan), which would seem to indicate that her communication system had the potential for productivity (Yule, 1999). Washoe also demonstrated understanding of a much larger number of signs than she produced and was capable of holding rudimentary conversations, mainly in the form of question–answer sequences.
  2. Nim Chimpski: The naming of this chimpanzee is very interesting and funny yet controversial. However, the naming is appropriate because this study has a correlation to Noam Chomsky nonetheless. He was born on November 19, 1973. Nim Chimpski was a chimpanzee who was the subject of an extended study of animal language acquisition at Columbia University, led by Herbert S. Terrace.

The validity of the study is disputed, as Terrace argued that all ape-language studies, including Project Nim, were based on misinformation from the chimps. R. Allen and Beatrix Gardner made a similar earlier study with Washoe (as elaborated earlier), in which Washoe was raised like a human child. Washoe was given affection and participated in everyday social activity with her adoptive family. Her ability to communicate was far more developed than Nim’s. Washoe lived 24 hours a day with her human family from birth; Nim at 2 weeks old was raised by a family in a home environment by his master to see if he could refute Noam Chomsky’s innateness hypothesis that language is inherent only in humans. Both chimps could use fragments of American Sign Language to make themselves understood

.

Chimpsky was given his name as a pun on Noam Chomsky, the foremost theorist of human language structure and generative grammar at the time, who held that humans were “wired” to develop language.

Project Nim was an attempt to go further than that of Washoe. Terrace and his colleagues aimed to use more rigorous experimental techniques, and the intellectual discipline of the experimental analysis of behavior, so that the linguistic abilities of the apes could be put on a more secure footing.

Terrace argued that since 98.7% of the DNA in humans and chimps is identical, some scientists (but not Noam Chomsky) believed that a chimp raised in a human family, and using ASL (American Sign Language), would shed light on the way language is acquired and used by humans. Project Nim, headed by behavioral psychologist Herbert Terrace at Columbia University, was conceived in the early 1970s as a challenge to Chomsky’s thesis that only humans have language” (Hess, 2008).

Attention was particularly focused on Nim’s ability to make different responses to different sequences of signs and to emit different sequences in order to communicate different meanings. However, the results, according to Terrace, were not as impressive as had been reported from the Washoe project. Terrace, however, was skeptical of Project Washoe and, according to the critics, went to great lengths to discredit it.

Conclusion

Upon observation of the several case studies it is clearly discernable to that humans are not the only kind with language as a specialized skill. Even if our languages are far more sophisticated than that of animals, the animals do not lag behind by much. Besides just empirical and trivial facts, scientists have located psycholinguistic proofs of such a claim as well. As presented in my paper, scientists have been already able to identify and detect Broca’s area in chimpanzees. Therefore, now the frontier has become twofold – the first one being the human mind and the latter one being the minds of animals.

Reference

Cantalupo C. , Hopkins, W. (2001) . Asymmetric Broca’s area in great apes. National institute of health public access, vol. 414(6863): 505 .  United States of America

Gleason, J. , Ratner, N. (1997) . Psycholinguistics. Geschwind-Wernicke model : Wadsworth Pulishing Limited.

Hess, E.  (2008) . Nim’s language. Nim Chimpsky: The Chimp Who Would Be human : Banton Publishers, United States of America

Koko. (December, 2011) . Wikipedia. Wikipedia online encyclopedia, Retrieved December 8, 2011 from http://en.wikipedia.org/wiki/Koko_%28gorilla%29

McGill Online. (December, 2011 . The brain from top to bottom. McGill University Online Resources, Retrieved December 6, 2011 from http://thebrain.mcgill.ca/flash/d/d_10/d_10_cr/d_10_cr_lan/d_10_cr_lan.html

Patterson, FG. (1978). “The gestures of a gorilla: language acquisition in another pongid.”. Brain and language 5 (1): 72, United States of America

Science Daily (2008, February 28 ). Chimps May Have A ‘Language-ready’ Brain. ScienceDaily. Retrieved December 8, 2011, from http://www.sciencedaily.com­ /releases/2008/02/080228124415.htm

Yule, G.  (2001) . The human language system. The study of language : Cambridge university press, United Kingdom.

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