Category Specificity, Alzheimer Disease and Normative Studies: A Review and Several Recent Instruments for Spanish Speakers

The study of category specific dissociations has enabled to postulate semantic knowledge has an internal structure that could depend on different neural substrates. Several studies have found that category/domain effects (i.e., a relative impairment of one semantic category/domain respect to the other) are present in patients with Alzheimer Disease. However, there is still some controversy about which semantic domain (living or nonliving things) is mainly affected or not by this selective damage. Some of these inconsistencies could be due to different methodological issues. Throughout this work some of them -such as the lack of control on nuisance variables or the consequences derived from ceiling effects- will be described. Our goal is to highlight the importance of conducting an adequate methodological control, in order to develop suitable assessment tools. Furthermore, we present different normative studies in Spanish that suitability face several methodological problems. It is our intention these works can be useful instruments for those interested in the study of the semantic processing and category specific deficits in Spanish language.