Functional symmetry and statistical depth for the analysis of movement patterns in Alzheimer's patients

Black-box techniques have been applied with outstanding results to classify, in a supervised manner, the movement patterns of Alzheimer's patients according to their stage of the disease. However, these techniques do not provide information on the difference of the patterns among the stages. We...

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Detalles Bibliográficos
Autores: Nieto Reyes, Alicia|||0000-0002-0268-3322, Battey, Heather, Francisci, Giacomo
Tipo de recurso: artículo
Fecha de publicación:2021
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/35234
Acceso en línea:https://hdl.handle.net/10902/35234
Access Level:acceso abierto
Palabra clave:Alzheimer’s disease
Dementia
Functional data analysis
Functional depth
Statistical data depth
Symmetry
Descripción
Sumario:Black-box techniques have been applied with outstanding results to classify, in a supervised manner, the movement patterns of Alzheimer's patients according to their stage of the disease. However, these techniques do not provide information on the difference of the patterns among the stages. We make use of functional data analysis to provide insight on the nature of these differences. In particular, we calculate the center of symmetry of the underlying distribution at each stage and use it to compute the functional depth of the movements of each patient. This results in an ordering of the data to which we apply nonparametric permutation tests to check on the differences in the distribution, median and deviance from the median. We consistently obtain that the movement pattern at each stage is significantly different to that of the prior and posterior stage in terms of the deviance from the median applied to the depth. The approach is validated by simulation.