Semantic Memory Deficits Assessment in Dementia of the Alzheimer Type (pp. 51-75)
Authors: (Lina Grasso and Herminia Peraita)
Abstract: The study of the organization and structure of semantic memory and the research of the representation of this knowledge constitutes one of the topics of great interest in cognitive Neuropsychology. It has been observed that, as a consequence of different lesions in the brain, the semantic memory system is selectively affected. In particular, it has been emphasized that there is a selective loss of the stored semantic information and dissociations among semantic categories.
Because of the diffuse types of lesions, Dementia of the Alzheimer type (DAT) affects the semantic memory in a gradual and progressive manner. The present article evaluates the impairment of semantic knowledge of some natural categories and artifacts, and the attributes that organize them conceptually in patients with Alzheimer‘s type dementia and in normal controls.
A semantic memory battery was developed in Spanish to assess this kind of knowledge in DAT (EMSDA: Evaluation Battery for Semantic Memory Deterioration in Dementia of the Alzheimer type, Peraita et al. 2001). This battery includes sub-tests such as Verbal Fluency of category exemplars, Category Definitions, Picture Naming, Attribute Recognition, Spoken word/Picture Matching, Sentence Verification, and Semantic Analogies. Among the different tasks, the stimuli are complementary in the visual/verbal modality, and the production and comprehension process.