Inverse Concrete Effect in Primary Progressive Aphasia-Semantic Variant: Longitudinal Study of a Patient Efecto de concretud inverso en Afasia Progresiva Primaria-variante semántica: Estudio longitudinal de un paciente

Abstract

Primary Progressive Aphasia (PPA) is a neurodegenerative disease which appears with progressive and insidious affectation of language. Current diagnostic criteria establish three different subtypes of PPA, each showing specific neurolinguistic profiles. Several researches have proposed a Reverse Concreteness Effect (RCE) as a main symptom for the Semantic Variant of PPA (sv-PPA), that is, a better performance with abstract than concrete concepts. Different explanations for this effect include: (a). pattern of neural degeneration, (b). patients’ educational level, (c). moment of disease progression. The aim of this work is to study the progression of concrete and abstract concepts processing in a patient diagnosed with sv-PPA. We used a synonyms judgement task where the subject has to indicate if two words are synonyms or not. The task include both concrete and abstract concepts. The patient was evaluated in three different moments (2014, 2015 and 2016). A better performance with abstract concepts was observed during the first evaluation. The RCE disappeared during the second assessment. The third time showed a reversed pattern. Our results
support those proposing that the RCE can only be found at initial stages of vs-PPA. The RCE appears to be related to the early degeneration of some portions in the Anterior Temporal Lobe which process visual features. These would be much more relevant for processing concrete concepts.