Please confirm you are human (Sign Up for free to never see this)
← Back to Search
Seizure Management In The Hepatic Porphyrias
Published 1984 · Medicine
TO the Editor: McCormick and Levine’ describe a patient who performed better on matching auditorily presented names to the corresponding objects than on naming the objects (presumably the same objects were used for both tasks, although this was not explicitly stated in the article). On the basis of this performance, it was concluded that the patient had a unidirectional (object-toname) disconnection limited to the visual modality. Inherent in this conclusion is the assumption that the two tasks require an equal amount of information processing and are distinguished only by the direction of information transfer. This is clearly not the case. Confrontation naming is essentially a free recall task, whereas matching an aurally presented name to an object is a forced-choice recognition task. The possible choices in the naming task include all the words in the subject’svocabulary as opposed to the small number of objects usually provided to choose from on matching tasks. The two tasks c h l d be made comparable in a variety of ways. For example, the naming task could be made into a forced-choice task, or the distractors on the matching task could be made phonologically or semantically similar to the target. Since these tasks were apparently not performed on this patient, one cannot conclude that the object-name deficit was unidirectional. Indeed, a more parsimonious and anatomically more feasible explanation would be a bidirectional but partial object-name deficit. The incompleteness of the deficit would account for the patient’s ability to name 50% of objects, a performance that the authors found “puzzling.” I t would have been informative to test this patient’s response to phonologic cues on those occasions when objects couldn’t be named. A benefit of these cues would be further evidence for the partial nature of the deficit. A second problem concerns the authors’ description of the patient’s dyslexia. They contend that their patient could not understand written words. In fact, although it was stated that she couldn’t read (presumably they mean aloud), no information regarding her comprehension of written words is provided. I t is well known that reading aloud is not an adequate test for comprehension.’ Tests such as matching written words to semantically related objects may reveal a surprising amount of comprehension in patients who are unable to read aloud. ’ Patients with modality-specific anomia are potentially a valuable source of information regarding the interaction of sensory processing, semantic information, and language. However, Ratcliff and Newcornbe‘ have convincingly argued that visual anomia may be a mild form of visual agnosia. If visual anomia is to be established as a distinct clinical entity, it will require the careful documentation of impaired object naming despite intact object recognition. Like other authors, McCormick and Levinel have used correct miming as evidence of object recognition. As Ratcliff and Newcombe have pointed out, the criteria for a successful mime are often too loose to ensure complete recognition. In addition, McCormick and Levine state that the patient “could always describe the use of the item” she couldn’t name. One would like to know whether these descriptions were of equal quality to descriptions of objects presented in other modalities and whether an independent judge could identify the target object based on the patient’s description of its use.