The Effect of Visual Perception on Confrontation Naming Performance: Alzheimer's Disease Versus Parkinson’s Disease with Dementia
Eun Jin Paek ; Young-Ho Sohn ; HyangHee Kim
Korean journal of communication disorders (언어청각장애연구)
Korean journal of communication disorders (언어청각장애연구), Vol.16(1) : 34~45, 2011
Background & Objectives: Generally, confrontation naming involves the visual-perceptive stage, the semantic stage, and the phonological output stage. Patients with Alzheimer's disease (AD) may exhibit increased errors in the visual-perceptive stage when performing confrontation naming tasks as the disease progresses. On the other hand, the nature of the confrontation naming ability in patients with Parkinson's disease with dementia (PDD) is not fully understood. The purposes of our study were to compare the visual perception and confrontation naming abilities between patients with AD and patients with PDD and to determine if patients with PDD also exhibit visual errors on confrontation naming tasks. We also studied whether the visual perception ability affects confrontation naming performance. Methods: The subjects included 32 patients with AD and 17 patients with PDD. We administered the Motor Free Visual Perception Test—Vertical Format and the Korean version of the Boston Naming Test to all patients. We classified the patients' erroneous naming responses into four types (visual, semantic, phonemic, miscellaneous) in order to qualitatively investigate the naming performances. Results: The visual perception abilities of the two dementia groups were lower than that of normal people, but there was no significant difference between the two dementia groups. Also, the patients with AD showed significantly worse performance on confrontation naming tasks than did the patients with PDD.
Furthermore, the two groups were not different in terms of the component ratio of error types. Discussion & Conclusion: We confirmed that the neuropathological changes in the two subtypes of dementia involve visual pathways that analyze the forms and shapes of visual stimuli. In view of the fact that the visual perception scores of the patients with AD had a significant effect on the ratio of visual error, our results support the visual hypothesis that has been proposed in previous studies.