PLoS ONE: Modeling Abnormal Priming in Alzheimer's Patients with a Free Association Network

full-text ►PLoS ONE: Modeling Abnormal Priming in Alzheimer's Patients with a Free Association Network: "Modeling Abnormal Priming in Alzheimer's Patients with a Free Association Network

Alzheimer's Disease irremediably alters the proficiency of word search and retrieval processes even at its early stages. Such disruption can sometimes be paradoxical in specific language tasks, for example semantic priming. Here we focus in the striking side-effect of hyperpriming in Alzheimer's Disease patients, which has been well-established in the literature for a long time. Previous studies have evidenced that modern network theory can become a powerful complementary tool to gain insight in cognitive phenomena. Here, we first show that network modeling is an appropriate approach to account for semantic priming in normal subjects. Then we turn to priming in degraded cognition: hyperpriming can be readily understood in the scope of a progressive degradation of the semantic network structure. We compare our simulation results with previous empirical observations in diseased patients finding a qualitative agreement. The network approach presented here can be used to accommodate current theories about impaired cognition, and towards a better understanding of lexical organization in healthy and diseased patients.

Javier Borge-Holthoefer1*, Yamir Moreno1,2,3, Alex Arenas1,4

1 Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Zaragoza, Spain, 2 Departamento de Fsica Teórica, Universidad de Zaragoza, Zaragoza, Spain, 3 Complex Networks and Systems Lagrange Lab, Institute for Scientific Interchange, Torino, Italy, 4 Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Tarragona, Spain

Abstract

Alzheimer's Disease irremediably alters the proficiency of word search and retrieval processes even at its early stages. Such disruption can sometimes be paradoxical in specific language tasks, for example semantic priming. Here we focus in the striking side-effect of hyperpriming in Alzheimer's Disease patients, which has been well-established in the literature for a long time. Previous studies have evidenced that modern network theory can become a powerful complementary tool to gain insight in cognitive phenomena. Here, we first show that network modeling is an appropriate approach to account for semantic priming in normal subjects. Then we turn to priming in degraded cognition: hyperpriming can be readily understood in the scope of a progressive degradation of the semantic network structure. We compare our simulation results with previous empirical observations in diseased patients finding a qualitative agreement. The network approach presented here can be used to accommodate current theories about impaired cognition, and towards a better understanding of lexical organization in healthy and diseased patients.

Citation: Borge-Holthoefer J, Moreno Y, Arenas A (2011) Modeling Abnormal Priming in Alzheimer's Patients with a Free Association Network. PLoS ONE 6(8): e22651. doi:10.1371/journal.pone.0022651

Editor: Matjaz Perc, University of Maribor, Slovenia

Received: April 28, 2011; Accepted: June 27, 2011; Published: August 1, 2011

Copyright: © 2011 Borge-Holthoefer et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: Y.M. and J.B.-H. are supported by the Government of Aragón (DGA) through a grant to FENOL. A.A. acknowledges financial support from Generalitat de Catalunya through project SGR2009 838. Y.M., J.B.-H. and A.A. are supported by the Spanish MICINN through projects FIS2008-01240, FIS2009- 13364-C02-01 and FIS2009-13730-02-02. A.A. acknowledges partial support by the Director, Office of Science, Computational and Technology Research, United States Department of Energy under Contract No. DE-AC02-05CH11231. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: Y.M. is a PLoS ONE Academic Editor.

* E-mail: borge.holthoefer@gmail.com

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Actualidad Ultimas noticias - JANOes - Investigan nuevas terapias contra la perdida de las facultades linguisticas en el Alzheimer - JANO.es - ELSEVIER: "ALZHEIMER
Investigan nuevas terapias contra la pérdida de las facultades lingüísticas en el Alzheimer

JANO.es · 02 Agosto 2011 13:54


En su fase inicial, esta enfermedad daña la memoria semántica, el sistema que posibilita el habla.

El Instituto de Biocomputación y Física de Sistemas Complejos (BIFI) de la Universidad de Zaragoza acaba de publicar en PLoS One los resultados de un estudio en el que se investigan alternativas para diseñar nuevas terapias contra la degeneración lingüística en enfermos de Alzheimer.

El Alzheimer, que afecta ya a cerca de 40 millones de personas en todo el mundo y que, según las previsiones, aumentará por encima de los cien millones en el año 2050, altera especialmente la capacidad lingüística desde la fase inicial de la enfermedad, dañando el sistema que posibilita esta facultad, la memoria semántica, ha informado la Universidad de Zaragoza en un comunicado.

Así, con el propósito de esclarecer cómo el lenguaje se ve afectado por la enfermedad, los investigadores del Instituto de BIFI Javier Borge-Holthoefer y Yamir Moreno, junto con Álex Arenas, profesor de la Universidad Rovira i Virgili, han elaborado un modelo teórico que simula el deterioro progresivo de las relaciones entre conceptos y predice determinados aspectos anormales que aparecen en las primeras etapas de los enfermos de Alzheimer y que no se observan en sujetos sanos.

El enfoque interdisciplinar del trabajo, inspirado en la metodología de la física estadística y las redes complejas con aplicación al ámbito cognitivo, 'permite abordar el problema desde una perspectiva novedosa, obteniendo resultados a los que sería imposible llegar de otro modo', concluyen el comunicado del centro universitario.


PloS One (2011); doi:10.1371/journal.pone.0022651
PLoS ONE: Modeling Abnormal Priming in Alzheimer's Patients with a Free Association Network: "- Enviado mediante la barra Google"

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