Nonverbal Cognitive Performance in Aphasic and Nonaphasic Brain-Damaged Patients

Abstract

In this study, the performance of left brain-damaged aphasic patients was compared respectively with that of left and right brain-damaged nonaphasic patients on four nonverbal tests of cognitive function, the Raven's Coloured Matrices, the Shure-Wepman Concept Shift Test, the Grassi Block Design Test and the Elithorn Mazes. Severity and type of aphasia were assessed using the Language Modalities Test for Aphasia. Results show that more severe aphasic patients, i.e., the pragmatic and, in particular, the global patients are impaired in their cognitive performance. Discussion of these findings led to the conclusion that aphasia, itself, is specifically a defect of language and memory for language which may or may not be accompanied by impaired cognitive functioning. Results also indicate that right brain-damaged patients obtained much lower scores on the Elithorn Mazes than testable aphasic patients, thus supporting evidence in the literature that right brain-damaged subjects have a central visual-spatial impairment. In relation to the differential diagnostic value of the tests, the absence of normal data limits the scope of statements that can be made. Nevertheless, it was found that the Elithorn Mazes have by far the highest potential value in differential diagnosis. It can be inferred, from the evidence presented, that this test differentiates right brain-damaged patients from those left brain-damaged patients who understand the instructions. The scores of right brain-damaged patients are markedly inferior to those of the left brain-damaged patients who were able to do this task.