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Chapter 3: Models and frameworks in neurolinguistics today 41

Global aphasia: the most serious type of aphasia, where the patient basically has no

linguistic ability;

Anomic aphasia: inability to name;

Isolated speech area: a combination of transcortical sensory and transcortical motoraphasia.

In reality, many patients are not easy to classify into any of these groups. In any model,

it is important to know whether the basis for classification is the combination of symp-

toms or the localization of the brain lesion. e term Brocas aphasia may, for example,

be ambiguous, standing for either the syndrome defined in the table above or aphasia

aer a lesion in Brocas area. ese terms are usually used in the former sense, that

is, based on symptoms. e two classification methods do not necessarily coincide; in

fact, they oen do not.

e suggested typical lesions for the aphasia types listed above are the follow-

ing:

Table 3.2. e most typical locations of lesions for the BDAE aphasia types

Aphasia type Most typical location of lesion

Wernickes aphasia Wernickes area

Transcortical sensory aphasia Posterior parietal lobe

Conduction aphasia Oen deep lesion between Wernickes and Brocas areas,

including white fiber bundles (the arcuate fasciculus)

Transcortical motor aphasia Area in front of the Rolandic fissure (the supplementarymotor area)

Brocas aphasia Brocas area

Global aphasia Large cortical and subcortical areas around the Sylvian fissure

Anomic aphasia Oen impossible to localize, traditionally said to result from

lesions affecting the angular gyrus

Isolated speech area Like transcortical sensory plus transcortical motor aphasia,

in so-called watershed areas (borders between the areas of

supply for the different arteries)

e lesions do, however, vary considerably and these types are statistically based gen-

eralizations.

Dynamic localization of function Luria

Luria saw the brain as a functionally connected system, where a task can be per-

formed by different mechanisms with the same result. e activity is complex and

demands cooperation between several zones. It is therefore not possible to localize a

language function in a certain area simply because the function is lost when that area