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Behavioural Neurology
Volume 15, Issue 3-4, Pages 87-97
http://dx.doi.org/10.1155/2004/974094

Test-Retest Reliability of fMRI During Nonverbal Semantic Decisions in Moderate-Severe Nonfluent Aphasia Patients

Jacquie Kurland,1,2 Margaret A. Naeser,1,2 Errol H. Baker,1 Karl Doron,1 Paula I. Martin,1 Heidi E. Seekins,1 Andrew Bogdan,1 Perry Renshaw,3 and Deborah Yurgelun-Todd3

1Harold Goodglass Boston University Aphasia Research Center, Department of Neurology, Boston University School of Medicine and the Veterans Affairs Boston Healthcare System, USA
2University of Colorado at Boulder, Departments of Speech, Language and Hearing Sciences and Neuroscience, USA
3Brain Imaging Center, McLean Hospital, Belmont, MA and Harvard Medical School, USA

Received 24 January 2005; Accepted 24 January 2005

Copyright © 2004 Hindawi Publishing Corporation and the authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Cortical reorganization in poststroke aphasia is not well understood. Few studies have investigated neural mechanisms underlying language recovery in severe aphasia patients, who are typically viewed as having a poor prognosis for language recovery. Although test-retest reliability is routinely demonstrated during collection of language data in single-subject aphasia research, this is rarely examined in fMRI studies investigating the underlying neural mechanisms in aphasia recovery.

The purpose of this study was to acquire fMRI test-retest data examining semantic decisions both within and between two aphasia patients. Functional MRI was utilized to image individuals with chronic, moderate-severe nonfluent aphasia during nonverbal, yes/no button-box semantic judgments of iconic sentences presented in the Computer-assisted Visual Communication (C-ViC) program. We investigated the critical issue of intra-subject reliability by exploring similarities and differences in regions of activation during participants' performance of identical tasks twice on the same day. Each participant demonstrated high intra-subject reliability, with response decrements typical of task familiarity. Differences between participants included greater left hemisphere perilesional activation in the individual with better response to C-ViC training. This study provides fMRI reliability in chronic nonfluent aphasia, and adds to evidence supporting differences in individual cortical reorganization in aphasia recovery.