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Alzheimer's patients engage an alternative network during a memory task
Author(s) -
Pariente Jérémie,
Cole Susanna,
Henson Richard,
Clare Linda,
Kennedy Angus,
Rossor Martin,
Cipoloti Lisa,
Puel Michèle,
Demonet Jean Francois,
Chollet Francois,
Frackowiak Richard S. J.
Publication year - 2005
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.20653
Subject(s) - functional magnetic resonance imaging , psychology , hyperactivation , task (project management) , magnetic resonance imaging , neuroscience , audiology , hippocampal formation , post hoc analysis , disease , medicine , management , economics , radiology
Abstract We conducted an event‐related functional magnetic resonance imaging experiment to better understand the potentially compensatory alternative brain networks activated by a clinically relevant face‐name association task in Alzheimer's disease (AD) patients and matched control subjects. We recruited 17 healthy subjects and 12 AD patients at an early stage of the disease. They underwent functional magnetic resonance imaging scanning in four sessions. Each of the sessions combined a “study” phase and a “test” phase. Face/name pairs were presented in each study phase, and subjects were asked to associate faces with names. In the test phase, a recognition task, faces seen in the study phase were presented each with four different names. The task required selection of appropriate previously associated names from the study phase. Responses were recorded for post hoc classification into those successfully or unsuccessfully encoded. There were significant differences between the groups in accuracy and reaction time. Comparison of correctly versus incorrectly encoded and recognized pairs in the two groups indicated bilateral hippocampal hypoactivation both when encoding and recognizing in the AD group. Moreover, patients showed bilateral hyperactivation of parts of the parietal and frontal lobes. We discuss whether hyperactivation of a frontoparietal network reflects compensatory strategies for failing associative memory in AD patients. Ann Neurol 2005;58:870–879