The idea of language seems relativelystraight forward, as it appears to be just a means of communicating; however,looking more in depth, it is a rather complex system, including severalunderlying concepts and processes. One of these critical concepts is “linguisticperformance,” or “the actual use of language in concrete situations” (Chomsky,1965, p. 4), which encompasses the language processes of both “production andcomprehension” (Pickering and Garrod, 2013, p. 329). Given that these processesare vital for communicating, it can be assumed that any impairment directlyassociated with linguistic performance would be detrimental. This idea comesinto question when dealing with aphasia, which is “a loss or impairment oflanguage due to some type of brain injury” that affects production,comprehension, or both, depending on the type (Agranowitz and McKeown, 1968, p.7).
It is important to note that aphasia doesn’t just impact the “verbalexpression” and “auditory comprehension” of linguistic performance, but itimpacts other “modalities” as well, including “writing,” “reading,” and evensigning (Nance and Ochsner, 1981, p. 421). Therefore, to understand the effectsaphasia has on language and its different modalities, it is necessary todistinguish the different types of aphasia as well as their individualcharacteristics. Consideringthat the language processes of production and comprehension are localised todifferent areas of the brain, an understanding of the brain is needed whenclassifying the different types of aphasia (Hudson, 2010, p. 65). The twopredominant language areas are “Broca’s” and “Wernicke’s area,” where productionis dealt with in “Broca’s area,” located in the frontal lobe, or the “anteriorportion of the left hemisphere,” and comprehension is dealt with in “Wernicke’sarea,” located in the temporal lobe, or the “posterior portion of the lefthemisphere” (Baker, LeBlanc, and Raetz, 2008, p. 149).
This means thatdepending on where the brain damage is located, whether it’s isolated to oraround Broca’s or Wernicke’s area, different symptoms heavily related to “expressive”and “receptive” language will surface (Edwards, 2005, p. 8). Because there are two main language sitesin which aphasia can occur, there are two main classifications of aphasia.
These include “non-fluent” and “fluent aphasia” (Edwards, 2005, p. 8), wherenon-fluent aphasia is associated with damage to or around Broca’s area, andfluent aphasia is associated with damage to or around Wernicke’s area. Obviously,the main distinction between the two categories of aphasia has to do withfluency, or the ease in which production of “many long runs of words in avariety of grammatical constructions” is adequately articulated (Goodglass andKaplan, 1983, as cited in Gordon, 1998, p. 673), however, even though theproduction aspect of language seems to be the identifying factor, comprehensionis just as central.Regarding non-fluent aphasia, since it’sspecific to Broca’s and the surrounding area, much of the impairment is relatedto production. Focussing on “the most widely discussed and researched” type (Edwards,2005, p.
8), which is “Broca’s Aphasia,” while both reading and auditory comprehensionare mostly unaffected when considering simple constructions, speech is”interrupted,” and “awkwardly articulated with great effort” and “abnormalintonation” (Goodglass and Kaplan, 1983, as cited in Gordon, 1998, p. 673;Baker et al., 2008, p. 149).
Pretty much the syntactic system, or grammar, and”access to vocabulary is compromised,” with the omission of “grammaticalfeatures such as determiners, auxiliary verbs, and verb inflections” (Edwards,2005, p. 8). Yet, the meaning of such productions is still comprehensible. As aresult, speech is ultimately reduced and telegraphic, making communicationstrained, but not impossible. For example, a sentence a non-fluent aphasicmight produce would be: “‘I go car'” (Kearns, 2005, as cited in Baker et al.
,2008, p. 149). So, although the meaning is clear, it’s definitely lacking thefiller words, or grammatical morphemes, that link the lexical items together. Writingability is affected much in the same way, where text is rather disjointed andagrammatic (Baker et al., 2008, p. 149).
The silver lining of non-fluentaphasia is that sufferers, since they have relatively good comprehension, can detectwhen they make mistakes; however, since they lack grammar, they can onlycorrect the content words, or the words that contain semantically relevantinformation (Murphy, n.d). Considering that getting one’s meaning across is theultimate goal, having the ability to correct errors regarding semantic intentis overall pretty useful. So, even though production is heavily impaired, theirability to communicate isn’t completely compromised. Another modality, most people forgetabout, that is greatly impacted by non-fluent aphasia, is sign language.
Poizneret al. (1987, as cited in Corina and Blau, 2016), explains that sign language,resulting from aphasia in the frontal lobe, is produced in a “simplified” and”agrammatic” way with “halting dysfluent…articulation” and improper handmovements to indicate “morpho-syntactic inflection” (p. 432). Therefore, eventhough sign language is relatively different from any kind of spoken language, “thelocation of brain damage seems to have remarkably similar (and specific)effects” (Campbell, MacSweeney, and Waters, 2007, p. 5), meaning that no matterthe language, expression is affected by non-fluent aphasia much in the sameway. Although many of these characteristics ofnon-fluent aphasia refer to Broca’s Aphasia, they do apply to the other typesas well, more so with “transcortical motor aphasia” than with “global aphasia”(Edwards, 2005, p. 8).
Transcortical motor aphasia results from brain damage tothe “supplementary motor area in front of Broca’s” (Murphy, n.d.), and the onlyaspect that truly separates this type from Broca’s, apart from the location ofdamage, is that transcortical motor aphasics have far better repetition (Wertz,Dronkers, and Ogar, 2004, p. 249-250); most other symptoms overlap. Global aphasics,on the other hand, are basically void of language in all domains (Agranowitzand McKeown, 1968, p. 37).
With damage to their “perisylvian fissures” (Murphy,n.d), thus both their frontal and temporal lobes, their speech is sparse, andthey have very little comprehension ability of both oral and written sources. Therefore,while there is clearly a wide range of characteristics regarding non-fluentaphasia, they impact all modalities of language in one way or another.In contrast, fluent aphasia, in thebroadest of terms, can be viewed as far more detrimental. Given the most commontype, or “Wernicke’s Aphasia,” not only does it severely impair production, butit compromises comprehension as well (Edwards, 2005, p. 9). This, in turn,drastically limits the ability to communicate.
With respect to speech, it isfluent and verbose, “resembling English syntax and inflection,” “without theeffort and hesitation associated with non-fluent aphasia” (Kertesz, 1982, ascited in Edwards, 2005, p. 17 – 8); however, it is unintelligible. Much of thedifficulty comes from the inability to recall lexical items, meaning that wordsand phonemes, either meaningless in context or made up, are often substitutedand repeated (Edwards, 2005, p. 1).
Therefore, several production errors, or”paraphasias” are extremely common (Lehtihalmes, 2004, p. 252). The most severeform, including vast “‘distortion of words'” and countless errors, is referredto as “jargon aphasia” (Eggert, 1977, as cited in Edwards, 2005, p.
11), where comprehensibilityof the aphasics’ production completely falls short compared to the that of Wernicke’saphasics, which is severely impaired to begin with.Now, Wernicke’s aphasics, compared to theirnon-fluent counterparts, actually have some grammar. Grammatical morphemes mayoften be omitted, within “‘confused and incomplete but not necessarilysimplified constructions'” (Goodglass and Hunt, 1958, as cited in Edwards,2005, p. 12), but they are not fully agrammatic. However, even though they arenot completely void of grammar, with all the errors they produce, they can’tseem to properly combine the jargon into cohesive and semantically coherent sentences.For example, an utterance a Wernicke’s aphasic might produce could be: “‘Youknow that smoodle pinkered and that I want to get him round and take care ofhim like you want before'” (Hudson, 2010, p. 65).
Just looking at the sentence,given that it contains both content and function words, it seems to mirrornatural speech; however, looking closer, it is evident that there are in factmade up words, substitutions, and improper grammatical features. Their writingparallels this kind of speech, just like that of non-fluent aphasics’, meaningthey produce lengthy amounts of fluent substance that make little sense. BecauseWernicke’s aphasics produce incoherent speech and writing, this suggests thatthey are not only “unware of their production” or written errors (Edwards,2005, p.
18), let alone the content of their own output, they also understandlittle of what is presented to them, both orally and written (Wertz et al.,2004, p. 250). This complete lack of error awareness truly exhibits the severecomprehension deficits this type of aphasia causes. These impairments are also quitenoticeable with sign aphasics. Corina et al. (1992, as cited in Campbell etal.
, 2007), discusses that when presented with prompts that elicit some type ofsign, even if the sign closely resembles their “real-world referents,” signaphasics are unable to understand the meaning, and thus unable to produce them(p. 13 – 4). The fascinating aspect is that, although sign aphasics are unableto produce the proper sign, they can easily produce the “pantomime gesture”regarding the action of the intended sign (Corina et al., 1992, as cited in Campbellet al.
, 2007, p. 14). The example she gives pertains to “a toothbrush,” wheresign aphasics couldn’t produce the sign for the word “toothbrush,” but theycould easily gesture the action of how to use one (Corina et al., 1992, ascited in Campbell et al, 2007, p. 14). Sign aphasics could also more readilycomprehend the meaning of gestures presented to them rather than signs. Forinstance, sign aphasics could easily comprehend a “frowning facial gesture” as”negation,” yet they couldn’t comprehend the sign for “negation” (Atkinson etal., 2004, as cited in Campbell et al, 2007, p.
15). It makes sense that, sincegesturing isn’t a language skill, it wouldn’t necessarily be impaired, but theapparent “dissociation” between sign aphasics’ language and gesturing isastounding (Campbell et al., 2007, p. 14). Circling back, Wernicke’s aphasia,although one of the most commonly diagnosed, is not the only type of fluentaphasia. The other types include “conduction” and “transcortical sensory”(Edwards, 2005, p. 7).
Each of the different types vary to some degree, justlike that of non-fluent aphasias, but in terms of comprehension, it iscompromised throughout each (Edwards, 2005, p. 7). That being said,comprehension in conduction and transcortical sensory aphasia is less severethan in Wernicke’s aphasia. Focussing on conduction aphasia, it results fromlesions to the “arcuate fasciculus,” which is a “white matter” tract thatconnects Broca’s and Wernicke’s area (Wertz et al., 2004, p. 250). This meansthat there is definitely a disconnect between language production andcomprehension, which results in an inability to repeat heard speech and writtentext.
Considering that this kind of aphasia results from damage notspecifically isolated to either of the language areas, but to the connectingpathway, it could be assumed that both production and comprehension would be ofgood quality. However, that’s not necessarily the case. Although comprehensionof conduction aphasics is the best compared to that of the other fluentaphasics, “it is not perfect” (Wertz et al., 2004, p. 250).
Also, conductionaphasic speech, while fluent, is filled with “numerous phonological errors” andreplacements of “words that sound familiar” to the intended words (Wertz et al,2004, p. 250). Therefore, the language process of production is definitely notunaffected either. In contrast, transcortical sensoryaphasics have excellent “verbal repetition” (Wertz et al.
, 2004, p. 250). Thisis due to damage concentrated to the area “behind Wernicke’s area” (Murphy,n.d.), which means that “phonological processing for … decoding” and thus somelevel of comprehension is still intact (Liberman et al., 1967, as cited in Boatmanet al.
, 2000, p. 1634). Among other symptoms, they produce a large amount of”stereotypic utterances, and verbal and syntactic paraphrases” (Baker et al.,2008, p.
149), but overall, symptoms of this type of fluent aphasia, apart fromthe repetition, are consistent with that of the others, in that the predominantfactors include those of impaired comprehension and fluent speech with “naturalspeech prosody” (Edwards, 2005, p. 17). After dissecting the relativelybroad disorder of aphasia, it is apparent that the different types, regardlessof fluency, vary in severity, in that some have less desirable effects thanothers on language.
While non-fluent aphasia, apart from global, predominantlyaffects production, fluent aphasia, more often than not, affects both theprocesses of production and comprehension. In any case, whether diagnosed withfluent or non-fluent aphasia, language across all modalities will definitely beimpacted.