The capacity to communicate is one of the fundamental elements of the human condition which separate people from the animal world. While almost all animals are capable of vocalizations and many have a rich and diverse method of communication; no animal can match the dexterity and abstract cognition of the human mind. The study of the way the brain processes, stores, and organizes information into learning has been studied for centuries—yet it has only been in the past few hundred years that true breakthroughs in the cognitive sciences has been observed. Arguably one of the most essential discoveries in brain function lies within the compartmentalization of mental, emotional, logistical, motor, and cognitive capabilities, this process began in earnest with the discovery of Broca's Area through the diagnosis of a particular symptom of trauma—Broca's aphasia. To understand the overall picture of this convoluted problem we must first examine the historical foundations through which aphasia was diagnosed. From there we will attempt to dissect the process of language evolution and attempt to recognize where aphasia fits within the equation of language structure. From structure, we must then look even closer to the actual biology of the neural network to examine how learning and language develops in order to assist in the therapy of aphasics the world over. Broca's area is a portion of the brain in the left temporal lobe which has been attributed to the process of speech. The term “aphasia” is derived from the Greek, aphatos, meaning “without speech”; although not all forms of aphasia silence the aphasic. As opposed to a learning disability which one grows up with, nor with diseases such as Alzheimer’s, aphasias are typified by beginning very suddenly with a trauma to particular portions of the brain. Thus and aphasia is basically a symptom of either a stroke or an acute head trauma and is, (in most cases), irreversible.1 The results of this particular symptom can be incredibly debilitating. Aphasia affects roughly the same number of people as Multiple Sclerosis or Parkinson's Disease and is sometimes accompanied by a paralysis or weakness in the right side. This is due to the fact that Broca's Area is positioned in the left hemisphere of the brain and contains many of the blood vessels that provide much-needed oxygen to areas of the brain that control the right side of the body. This partial-paralysis is known as “hemiplagia”.2 Specifically, Broca's aphasia targets the motor portion of the speech process. Aphasics may be able to cognitively understand the basic gist of what you are attempting to say, but their speech is halted and lacks vital articles, pronouns, and grammatical structure. Aphasia does not affect personality and in many ways does not diminish cognition in areas that are not related to language processing. Their understanding of language may only extend to sentence-long pieces of information and aphasics can become easily confused with grammatical ambiguities, just as pronouns and passive sentences; however, the major determinant of Broca's aphasia as opposed to other types of aphasia lies in the patient's basic ability to comprehend what is asked of him, but inability to fluently respond. To examine the unique consequences of a trauma affecting Broca's Area, one may look to the example of John, who suffered a stroke to the left temporal lobe: he could not match a razor or watch with the words razor or watch, but could play chess, add and subtract, (but not multiply and divide), recognize people he hadn’t seen for years, write down all the historic dates he eve knew or how much you ought to pay for a house or car or what time someone was coming to tea. Although he had difficulty signaling “yes” or “no”, he could indicate by facial expression and tone of voice whether or not he agreed with a friend's theories about any subject that had ever interested him; he could read or draw maps, plan a day or a journey, find his way around town. The study of aphasia suggests that meaning, concepts and facts are stored differently in the brain from the dictionary of words and grammatical rules that are used to represent them. 3

To understand the facets of this remarkable syndrome, we must first examine the history of its emergence and impact on the world of neurology. Born in 1824, Pierre Paul Broca was born near Bordeaux, France the son of a Huguenot doctor who quickly displayed an aptitude for physiology, surgical procedure, and anthropology. While Broca’s contributions to the medical field were vast and he soon became the contemporary of such legends as Charles Darwin an Louis Pasteur; yet for all his surgical prowess, his greatest work had both medical and anthropomorphic possibility. Known as the progenitor of modern theories of brain lateralization; Broca was one of the first to truly delineate a specific region of the brain that is primarily responsible for a single cognitive capability, primarily the function of speech. His legacy began when meeting a 38-year old laborer who had been kicked in the head by a horse. While there was no evidence of skull fracture, within one month the patient had begun to show signs of aphasia, responding to all questions with “it is not going badly”. After some time, the patient slipped into a coma and passed away; an autopsy later revealed lesions in the left temporal lobe, beginning a process of discovery that would determine the locus of the speech centers in the brain, a complete shift in the way we examine brain function began with the utterances of a single individual, kicked in the head by an unruly horse. Fascinated, Broca began to clarify his theorem at a hospital at Bicetre where a patient nick-named “Tan” by the staff, (as it was one of the few words he was capable of saying), was suffering from a neurosyphilitic lesion on his left temporal lobe which over the years had rendered Tan the capacity to only say the word “tan” over and over again. After meeting the patient, Broca accurately predicted that a lesion existed and the location of the trauma in the brain; which was later verified through post-mortem examination. Broca developed several methods to determine a relatively accurate localization of lesions prior to the extent of a craniotomy. In the process he invented over 27 in the effort to specifically determine the relationship of the brain to the skull casing. This coupled with other similar experiments led Broca to make the definitive claim that he had discovered the location of speech capacity and recognition in the brain.4 Broca was not the first person to hypothesize that specific locations of the brain were responsible for specific functions. For example, Franz Joseph Gall pioneered the idea of brain localization and established phrenology, or the study of the mind. However, Gall’s theories were quickly disproved as he had surmised that brain function dealt with many miniature “organs” that were each responsible for a single aspect of human cognitive capabilities. Since Gall believed that he had unlocked a physiological understanding of brain function, he later posited that the physical characteristics of the skull and brain could actually give credence to the type of person that individual was, from intellect to levels of morality. While this theorem was sorely incorrect, the concept of localized brain function had been established.5 Other individuals who had been previously toying with the concept of lateralization included Pierre Flourens, who had earlier demonstrated through experimentation on animal brain function that when certain areas of the brain were damaged and/or destroyed, the overall cognitive capability of the creature would change, depending on the location of the trauma. This was a remarkable step in the field of neuroscience and led Broca to the belief that not only is the brain divided into specific hemispheres responsible for overall function; but that localized areas could be small, and have highly specified purposes. To understand exactly what this discovery would mean to the scientific community one must delve into not only the physiological aspects of the way the brain works, but the evolutionary theories surrounding speech development and anthropological consequences of lateralization upon societal evolution. To assist the of Broca’s aphasia, researchers are attempting to specify the exact method by which language has evolved through the course of human development in order to exactly specify where the breakdown may be occurring, be it a phonological, syntactical, lexical, or semantic breakdown. While languages may be diverse, the building blocks of language remain the same. One of the most distinctive aspects of human species is our capacity for a complex and rich method of communication that extends beyond the concrete to encompass the ability to express incredibly abstract and ethereal concepts through simple sounds. The study of how language is built is called phonology. Not to be confused with phonetics, which is the physical method by which sound is produced, phonology discusses the function of sound within the organizational structure of a language. In phonology, speech is grouped into phonemes, or “the shortest segment of speech that, if changed, would change the meaning of a word.”6 While they are similar, a phoneme is not a syllable, a phoneme can be one sound or a collection of sounds; for instance, the English language has an agreed upon 13 vowel phonemes and 24 consonant phonemes because letters may be pronounced vastly different ways.7 Because pronunciation differs person-to-person, so can phonemes; adding an additional layer to the basic units of speech. So in the case of Broca’s aphasia, patients have a significant problem with easily stringing together phonemes, as opposed to Wernicke’s aphasia, where patients are easily capable of expressing sound but have significant complications with the second breakdown of language, syntax. Syntax is simply the rules by which a language is governed. Syntax for English speakers is vastly different from those fluent in the romance languages, whereas a noun follows an adjective in English it is the exact opposite in Spanish; these grammatical rules are a part of the syntax which defines all language. Once the rules for language are determined, the lexicon decides the actual meaning of these arbitrary combinations of phonemes—thus the vocabulary is created. Broca’s aphasia may affect syntax and lexicon to some extent, but in comparison to other types of aphasia it is production of sound itself that appears to suffer. The final portion of language is semantics, or the ability to understand subliminal messaging encoded into the facial expressions, body language and emotion of the individual conveying information. From just this simple breakdown of how language is organized we can glean some of the basic fundamentals of how Broca’s aphasia works. The evolutionary process of language development is rife with contention and differing theories of how and where the split truly began from our hominid ancestry who lacked the method to convey abstract thought. Regardless of the theory of why it began, it is integral to our understanding of Broca's area to recognize how it began. Schools of thought abound to explain the whys and wherefores of language evolution, from Dean Falk's “Put the Baby Down” theory, illustrating that language began when newly-bipedal humanoid mothers had to set their infants down in order to forage for food and thus had to create a specific method of verbal communication in order to remain in contact and control their baby's behavior8 to Lieberman's “Two-Tube Theory” specifying that the physiological development of a two-tubed vocal tract with horizontal oral and vertical pharyngeal components, from a single tubed tract, was the crucial event9. But the true question for Broca's patients is the how. What makes this small portion of the temporal lobe so integral to language learning and expression? How does Broca's Area relate information stored locally throughout the brain and to locations even on the other hemisphere? One answer may lie within the concept of mirror neurons. In the late 1980s and 90s, a team of Italian neurophysiologists set out to discover the link between observation and imitation. The two may seem trivial to the casual observer, as it is a trait that all humans are capable of doing without a moment's thought; however, when viewed from a physiological perspective, the results are astounding. The portions of the brain that actually process visual information and those that control motor function are completely separate entities. Thus, the capacity to view an action and immediately know how to replicate that action physically indicates a very heightened level of synaptic connection and learning capacity. The experiment was simple, utilizing an infant macaque monkey and focusing on a single neuron located in the homologue of Broca's Area, it was discovered that the neuron would fire the exact same way when the monkey both observed facial expressions and imitated making them. The neuron would not fire when other, meaningless gestures were made. These results became even more impressive when the monkey's neuron would fire when both observing a paper being torn without sound and simply hearing a paper shredding without visual stimuli. Upon humans the effect is compounded. Researchers soon discovered that mirror neurons were activated most significantly when human subjects were stimulated with a complex physical cue, such as an expert guitarist playing chords.10 What this demonstrates is that the capacity for imitation is even further exploited within the human psyche. While a macaque monkey may be capable of matching the physical action of a physical object being torn to the sound of the destruction of that physical object, human beings are capable of processing mirror neurons when even abstract or highly complicated stimuli are perceived, and herein lies the potential for language evolution. A majority of mirror neurons exist within the left temporal lobe and specifically within Broca's Area, since these mirror neurons fire most when a physical stimuli is presented and imitated, it can be surmised that Broca's Area in the frontal cortex is responsible for the mechanical apparatus of the speech process. This is further corroborated when one realizes that of the four distinct categories of language development, (phonological, syntactical, lexical, or semantic), the aphasic suffers most from formulating appropriate phonemes to match the lexical and semantic information that they widely understand but cannot articulate. Like any evolving theory, experimentation and research is essential toward legitimization. For instance, recent evidence has come to light that truly explores the capabilities of the brain's malleability and capacity for learning even when trauma has occurred. To do this, researchers have begun to look at the process by which an infant or child brain accepts and stores new information. If we followed the original surmising of Franz Joseph Gall we would believe that simply looking at the physiological structure of the child's skull would give us indicators of the type of person he or she would become and what their developing brain would most easily learn. However, recent evidence indicates that these specified learning areas that Broca so ingeniously discovered may be more fluid in their potential than the likes of Gall ever imagined. Researchers Greenenough, Black, and Wallace illustrated just how synaptic connections are not concretely fixed at birth but shaped by experience: To use a computer analogy, we now think that the young brain is like a computer with incredibly sophisticated hardwiring, but no software. The software of the brain, like the software of desktop computers, harnesses the exceptional processing capacity of the brain in the service of specialized functions, like vision, smell, and language. All individuals have to acquire or develop their own software in order to harness the processing power of the brain with which they are born.11

To explore this concept, neurons from young rats were moved from the visual cortex and transplanted to regions that are linked to bodily and sensory functions. The transplanted neurons took on the aspects of sense receptors instead of maintaining visual capacity. The same happened when neurons from the auditory centers became visual when moved to the cortex. This illustrates; (at least in the rodent brain), that while the areas of the brain may be linked to particular areas of learning this does not limit what synaptic connections could potentially be forged; it is the overall location of the brain and not the type of synapse which determines sensory input.12 While such experimentation can only be conducted upon animals and not humans, it gives credence to the thought that while certain areas of the brain are more prone to storing and processing information on a specific function, they are not the only areas involved in the learning process. For instance, while the majority of individuals rely on the left temporal lobe for communication and language, approximately 10% of normal right-handed individuals will rely on the right temporal lobe for the same information, and in left-handed individuals that percentage may rise.13 Also, males and females may forge different neural pathways and have different methods of achieving lateralization, or the use of both hemispheres. Individuals with developmental disabilities will have drastic differences in the locus of brain function, but this does not mean that these individuals are incapable of learning.14 As the human brain learns, an arduous process of forging synaptic connections between certain areas of the brain commences—thus the process of learning can be complicated, frustrating, and time-consuming. This is because data is not stored simply in one area; for instance, the word “cat” may simultaneously trigger several areas of the brain. The audio portion where the sound “cat” is either heard or conceived of, the visual portion with the image of a cat, perhaps memory banks of a beloved pet—this parallel processing makes the human brain unique from other systems, even those as fast as an actual computer, where a pathway must be completed before moving on to the next query. Humans are capable of making countless connections off of a single stimuli and accessing that information again almost instantaneously. While the pathways may become duller from disuse, once they are forged it becomes much faster to re-access the data even years later.15 So what does this mean for the victim of Broca's Aphasia? The short answer is that it means that while recovery may not be capable for many individuals and full recovery will almost never happen—there are possibilities available to improve quality-of-life and cognitive capabilities even with severe damage to the left temporal lobe. Three categories determine the effectiveness of therapy and treatment, those being Substance, Sustenance, and Cost16—meaning, is it worthwhile, take effect, and feasible to do? Therapist Judith Duchan explains that the role of communication is often taken for granted in those who have never been affected by aphasia, but aphasics are essentially entirely cut off from human society because they lack the capacity for even basic “chit-chat”. Their link to the outside world is tenuous at best and relationships begin to suffer. Thus, a therapist must first examine methods to improve the quality-of-life of the patient in order to begin the process of tapping back into the basics of human communication. The process is as simple as a game of Pictionary. So far we have illustrated that sensory processes are dedicated to certain portions of the brain which are activated by mirror neurons by a perceived stimuli, and that the cells within these areas possess a certain tenacity for regrowth. Thus, instead of attempting to work out an atrophied muscle it instead makes more sense to work all the muscles around it in order to provide stability and hopefully promote recuperation. In the case of Patty, an elderly grandmother who had suffered a stroke, Duchan began a multi-echelon course of treatment. It is absurd to simply attempt to re-teach the patient the English language because the cognitive and motor processes have been interrupted. Instead, a simple code of words were created out of Patty's existing lexicon in order to indicate interest or basic wants. Next, Patty was reintroduced to society as a volunteer at a local bookstore, here she was working in a low-stress environment and permitted to do do organizational work which dealt with numbers instead of words. Her successes here led to another breakthrough. If the brain processes information differently depending on area, then areas that are responsible for numbers or spatial understanding should be basically unaffected by Broca's Area—as a result Patty began to draw. While no proclaimed Michelangelo, Patty's drawings quickly reestablished a line of communication with her granddaughter, Megan. Through the use of a comic-strip template in which Patty drew the pictures and Megan filled in the word bubbles, a form of communication emerged. In this new treatment, no emphasis was placed on drilling language, instead all tactics were based on improving the quality-of-life of the affected individual by looking at Broca's aphasia as a disability and not an impairment.17 Therapist Roberta Elman also proposes another insight to the therapeutic necessities to counter aphasia, she describes traditional aphasia approaches similar to a beginner learning piano. You memorize certain set of notes which you can produce quickly and fluently upon command, but the moment that you are asked to compose something of your own, all understanding of the way that sharps and flats work becomes divided from your ability to press the keys. This, (in essence), is precisely how Broca's aphasia works. Unaffected individuals are like master jazz players, they are capable of nearly-instantaneous improvisation to successfully convey a story. Most speakers have a basic understanding of the idea they want to communicate but the words and methods by which they accomplish this are not set in stone ahead of time. As this is a reflection of the inspiration of fluent conversation, it stands to reason that a therapist-driven series of language tasks would be completely ineffective in forcing the fledgling “piano player” to improvise a sheet of music. Thus, Elman took a cue from the likes of Dizzy Gillespie and began a jam session. Aphasics were invited to group sessions, where they could communicate to each other in a safe and stress-free environment, taking patterns and strategies off of one another and utilizing the cues of each others' strengths in order to forge new relationships and language capacities.18 Jazz music on an excellent analogy, but just as jazz promotes ingenuity, so should all potential methods of treatment. One must remember that innovation is one of the cornerstones of humanity: chefs, scientists, artists, dancers, athletes and mathematicians all utilize improvisation on a daily basis while activating differing parts of their cortical network. The answer to effective treatment lies in recognizing the patient's strengths and encoding meaning into that portion of their life in order to regain a sense of community and self-empowerment. In this way, the loss of conventional conversation may be mitigated and overall quality-of-life improved through exploiting our knowledge not only of the method by which language evolved into separate building blocks, but also how this information became encoded into a language, where the code failed in the aphasic, how each individual brain differs physiologically in its cognitive functions and compartmentalization, and finally how the therapist can drive the creative process to re-establish communication.

Works Cited:

Banich, M.T. (1997). Neuropsychology: The Neural Bases of Mental Function. Boston: Houghton-Mifflin.

Bigler, E.D. (1992). The Neurobiology and Neuropsychology of Adult Learning Disorders. Journal of Learning Disabilities, 25.

Dehaene, S. (2005). The Mirror Neuron System and Its Role in Imitation and Language. From Monkey Brain to Human Brain: a Fyssen Foundation Symposium. Cambridge, MA: MIT Press.

Duchan, J. F., & Byng, S. (2004). Making a Difference in Everyday Life. Challenging Aphasia Therapies: Broadening the Discourse and Extending the Boundaries. Hove: Psychology Press. Falk, D. (2009). Finding our Tongues: Mothers, Infants, and the Origins of Language. New York: Basic Books.

Goldstein, B. (2010). Speech Perception. Sensation and Perception. Belmont: Wadsworth. (Original work published 2007).

Greenenough, W.T., Black, J.E., & Wallace, C.S. (1993). Experience and Brain Development. In M. Johnson (Ed.), Brain Development and Cognition: A Reader. Oxford: Blackwell.

Hale, S. (2007). The Man who Lost his Language: a Case of Aphasia (Rev. ed.). London: Jessica Kingsley Publishers.

Lieberman, P. (2000). Human Language and our Reptilian Brain: the Subcortical Bases of Speech, Syntax, and Thought. Cambridge, Mass.: Harvard University Press.

O'Leary, D.D., & Stanfield, B.B. (1985). Occipital Cortical Neurons. Brain Research, 336.
Sabbatini, Renato. "Phrenology, the History of Brain Localization." Brain & Mind . Feb. 1997: Brain & Mind. Web. 16 Aug. 2012.

Toledo-Pereyra, L. H. (2005). Vignettes on Surgery, History, and Humanities. Landes Bioscience.