Seyed Amir Hossein Batouli1, Razieh Alemi2, Haleh Khoshkhouy Delshad3, Mohammad Ali Oghabian4. 1. Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehranf University of Medical Sciences, Tehran, Iran; Neuroimaging and Analysis Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran. 2. Department of Otolaryngology, Faculty of Medicine, McGill University, Montreal, QC, Canada; Centre for Research on Brain, Language, and Music (CRBLM), Montreal, QC, Canada; International Laboratory for Brain, Music, and Sound Research (BRAMS), Montreal, QC, Canada. 3. Department of Cognitive Science, Faculty of Human Sciences, Macquarie University, Australia. 4. Neuroimaging and Analysis Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: oghabian@sina.tums.ac.ir.
Abstract
OBJECTIVES: Memory is an important brain function, and is impaired with brain lesions. Resection of the lesion is one solution for that, but presurgical planning (PSP) is needed to guide the surgery for maximum removal of the lesion, as well as maximum preservation of the function. Functional Magnetic Resonance Imaging (fMRI) is one of the best approaches for such a purpose, but performing an fMRI study needs careful consideration of the factors which influence its results. Studies have shown that mental fatigue does have the potential to alter brain functions, and therefore this study aims to identify if mental fatigue should also be considered as a confounding factor when performing an fMRI study, particularly for clinical purposes. PATIENTS AND METHODS: Using 57 healthy young volunteers, face and word encoding tasks were performed, with half of the participants performing the memory tasks after a set of language tasks and half of them before that. RESULTS: The results showed that mental fatigue led to increased activity in the bilateral thalamus and caudate in the face encoding task, and in the right thalamus, posterior cingulate and medial temporal lobe in word encoding. In addition, activation was declined with mental fatigue in the left lingual, precuneus, and posterior cingulate gyri in face encoding. CONCLUSION: This study has shown the importance of the number and sequence of cognitive/mental tasks when performing an fMRI study, which could help to obtain more reliable fMRI maps in clinical applications. This finding is also important for performing research/cognitive studies using fMRI. Crown
OBJECTIVES: Memory is an important brain function, and is impaired with brain lesions. Resection of the lesion is one solution for that, but presurgical planning (PSP) is needed to guide the surgery for maximum removal of the lesion, as well as maximum preservation of the function. Functional Magnetic Resonance Imaging (fMRI) is one of the best approaches for such a purpose, but performing an fMRI study needs careful consideration of the factors which influence its results. Studies have shown that mental fatigue does have the potential to alter brain functions, and therefore this study aims to identify if mental fatigue should also be considered as a confounding factor when performing an fMRI study, particularly for clinical purposes. PATIENTS AND METHODS: Using 57 healthy young volunteers, face and word encoding tasks were performed, with half of the participants performing the memory tasks after a set of language tasks and half of them before that. RESULTS: The results showed that mental fatigue led to increased activity in the bilateral thalamus and caudate in the face encoding task, and in the right thalamus, posterior cingulate and medial temporal lobe in word encoding. In addition, activation was declined with mental fatigue in the left lingual, precuneus, and posterior cingulate gyri in face encoding. CONCLUSION: This study has shown the importance of the number and sequence of cognitive/mental tasks when performing an fMRI study, which could help to obtain more reliable fMRI maps in clinical applications. This finding is also important for performing research/cognitive studies using fMRI. Crown