The linguistic impairment of the perfect aspect in Alzheimer’s disease and logopenic primary progressive aphasia

Taking into account that neuropsychological studies with subjects with language pathologies can contribute to the investigation of the organization of syntactic knowledge, the objective of this work is to investigate the syntactic representation of the perfect aspect based on data from subjects with pathologies that affect their language. More specifically, we aimed to investigate the possible phrases associated with the types of the perfect aspect and the hierarchy among them. This work aims to investigate the syntactic representation of the perfect aspect. Therefore, we sought to verify a possible linguistic impairment of this aspect in individuals diagnosed with Alzheimer's Disease (AD) and Primary Progressive Logopenic Aphasia (LPPA). A double case study was carried out with one patient with AD and another with LPPA. The methodology consisted of applying functionality tests, neuropsychological tests, and linguistic tests. The results indicated that both the AD patient and the LPPA patient present functional decline and cognitive impairment, with the degree of impairment of the first patient being more extensive than that of the second one in both cases. Regarding language, the patient with AD showed impairment with all four types of perfect, present tense, and imperfective aspect, whereas the LPPA patient has shown impairment only in perfect of recent past and present tense. Based on the results we propose the existence of a phrase to perfect of recent past and the dominance of the temporal phrase over the perfect phrases in the syntactic hierarchy.