Damasio and Damasio (1992) discussed the detailed mechanics of language processing by the human brain. Their article, first established a general understanding of such concepts as the brain’s ability to categorize and classify word-forms through the mediation of the human sensors. According to their article, the brain’s left and right hemispheres contains three neural structures. The first extensive structure processes the non-verbal representations organizing objects, events, and relationships.
Second structure, located only in the left hemisphere is responsible for producing the language through and with phonemes, phonemic and syntactic structures with the resulting word-forms. They referred to the third structure as a mediating structure that can change the concept into the word form or vice versa. Their further discourse proceeded into the specifics of the brain anatomy and various effects of the damage or lesions of the portions of the brain. Their examples with the color recognition were particularly impressive when they described the condition known as achromatopsia – lack of ability to perceive colors (i.
e. seeing the environment in the shades of gray). The article was especially effective in describing the complicated mechanism behind the color recognition, color categorization and classification, and producing the correct word-form for the specific color. The article argues against the traditionally thought the “pictorial” representations of the objects, persons, or any combination of the environmental experiences but instead the authors describe their theory of how records of neural activity are stored in the sensory and motor cortices.
Such patterns of synaptic activity also act through and with associations on which one particular object will associate with the patterns of color, shape, usage, tactile perceptions, and the feelings that a person has usually when using this object. The authors further state that the neural actions that occur as the result of interaction between the person and the object happen in different functional areas of the brain and come together in areas of “convergence” of synaptic connections.
Then recall of the event and its associated experiences depend upon simultaneous reactivation of the neural actions within the neuron assemblies when those fire simultaneously and reactivate the previously occurred patterns of neural activity. Simultaneously, the categorization and classification occurs in such similar or related neural actions are activated together. The categorization and classification abilities of the first neural structure make it possible to distinguish objects by their characteristics and function ‘stored’ previously, as Damasio and Damasio describe the example with a coffee cup.
Such ‘recollection’ is perhaps responsible for the brain’s ability to express the formed within concept and to understand a comprehensive input as the concept. The article further exemplifies a curious condition in which a patient would loose an ability to define a concept for a unique entity (like an animal species in the author’s example). From this example, the reader would learn that the affected patient would not be able to name any animal species (i. e. raccoon) nor would say its size, color, or shape.
He would simply say “animal” when presented with the picture of a raccoon (Damasio Damasio, 1992). When describing the affect produced by the specific lesion of the portion within the left hemisphere, the authors wrote about the earlier discovery by Paul Broca and Carl Wernicke of the phenomenon called ‘cerebral dominance’ which specifically pointed out at the left hemisphere as the organ responsible for the production and processing of human language in “99 percent of right-handed and two-thirds of left handers.
” The article confirms these studied by briefly discussing the research by Edward Klima of the University of California at San Diego and Ursula Bellugi of the Salk Institute of Biological Studies in San Diego who have discovered that aphasia (condition that impedes language-interpreting ability) is caused by damage to the particular region of the left hemisphere of the brain. Using the aphasic patients, the investigators were able to map the neural activities responsible for the formation of the language and its interpretation (also including other variations of language such as sign language) (Damasio & Damasio, 1992).
With having a map in front of them, the neuroscientists and other field investigators would be able to specify exactly which function would be impaired as the result of damage to which portion of the left hemisphere. This would also extend to the predictive ability as far as other functions of the whole language production mechanism are concerned. Example of such can be actual production of speech sounds, intonation (i. e.
speaking in a ‘flat tone’, long pauses between the words and defective grammar), the impairment of associative and habit learning, production of nouns, production of verbs (nouns and verbs are produced and processed in different regions), difficulty understanding meanings that represent the syntactic structures, and the inability to understand the meaning of non-reversible passive structures. The authors further attempt to defend their point of view in favor of the mediating system between the structure that is responsible for concept processing and the system that actually produces word and word structures.
According to them, the mediating system’s function would be that of the selection of the correct meaning of lexicon or that connecting the concepts’ interrelationship. It is understood that mediation system is mostly activated when the person attempts to understand the comprehensive input. The purpose of comprehension sets in motion the mediating system that is capable of bringing associative connections between the concepts, particular experiences, and generalized experiences together. To exemplify their view, the authors mention A. N. and L. R.
as patients who have a problem in retrieval of common nouns representing certain entities. Their deficit in the specific word-form retrieval is causes by their inability to activate the mediation system that deprives them of the ability to bring the connection between the concepts (i. e. of the noun and what that noun represents as far as the object and its function). Damasio and Damasio explained such selective deficiency by stating that the selectivity in conceptualization of entities depends upon the absence or presence of the personal relation of the patient to the entity/concept.
By loosing the function of some regions of the left hemisphere, the patients will respond by loosing the specific speech/conceptualization function that is mapped to that region. In A. N. and L. R. case it was the damage to anterior and midtemporal cortices that rendered them unable to pick may common nouns. The article concludes with the detailed discourse into the studies by the group of researchers at Washington University.
Specifically, this group was interested in the production and interpretation of verbs and functors and how the nouns can be mediated together with the appropriate actions, like the noun ‘apple’ would mediate with the verb ‘eat. ’ Their conclusions illustrated a situation in which the damage to the certain left hemisphere regions would disrupt such association rendering the patient unable to produce the appropriate verb and further disrupting their use of grammar (Damasio & Damasio, 1992).
The article was comprehensive in its purpose in terms of being able to describe the complex structure and function of the left hemisphere’s regions responsible for processing, production, and mediation of the components of human language. The only critique of the article that I have is that the authors attempted to place too much of very specific information into a very small format. The complexity of the concepts behind the message would be better delivered if more practical examples were used and the text would be delineated with a larger number of lay terms.
In general, the article’s audience appeared to be professionals or paraprofessionals who already had a significant understanding within the field. It would be difficult to understand for people with a limited knowledge and background within the field. The illustrations were adequate and the sources appropriate in both quality and quantity. My suggestion for the further research would be targeting the Visio-Spatial Memory Units that are units of memory assembled from different perceptual input within the Working Memory (Baddely, 1992).
Further, my suggestion would be to investigate the alternative approaches to the definition and theoretical function-ability of the short-term memory. References Baddeley AD. 1992. Working memory. Science 255:556-59 Damasio, A. R. , & Damasio, H. (1992). Brain and Language, Scientific American, pg. 89- 95, Retrieved June 28, 2007 from http://www. utdallas. edu/~wkatz/Proseminar_articles. html