AUTHOR=Gkiatis Kostakis , Garganis Kyriakos , Karanasiou Irene , Chatzisotiriou Athanasios , Zountsas Basilios , Kondylidis Nikolaos , Matsopoulos George K. 

TITLE=Independent component analysis: a reliable alternative to general linear model for task-based fMRI

JOURNAL=Frontiers in Psychiatry

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2023.1214067

DOI=10.3389/fpsyt.2023.1214067

ISSN=1664-0640

ABSTRACT=Functional Magnetic Resonance Imaging (fMRI) is a valuable tool for the presurgical evaluation of patients undergoing neurosurgeries. Although many pre-processing steps have been modified according to the advances of the recent years, statistical analysis remains mostly the same since the first days of fMRI. In this study, we examine the ability of Independent Component Analysis (ICA) to separate the activation of a language task in fMRI and we compare it with the results of General Lineal Model (GLM).Sixty patients, undergoing evaluation for brain surgery due to various brain lesions and/or epilepsy, and twenty control subjects completed an fMRI language mapping protocol that includes three tasks resulting in 259 fMRI scans. Depending on brain lesion characteristics, patients were allocated to (1) Static/Chronic not-expanding Lesions (Group 1) and (2) Progressive/expanding Lesions (Group 2). GLM and ICA statistical maps were evaluated by fMRI experts to assess the performance of each technique.In the control group, ICA and GLM maps were similar without any superiority of either technique. In both, Group 1 and Group 2, ICA performed statistically better than GLM with a p-value of p<0.01801 and p<0.0237, respectively. This is an indication that ICA performs as good as GLM when the subjects are able to cooperate well (less movement, good task performance), but ICA can outperform GLM in the patient groups. When both techniques were combined, 240 out of 259 scans produced reliable results showing that the sensitivity of fMRI task-based can be increased when both techniques are integrated in the clinical setup.ICA may be slightly more advantageous, compared to GLM, in patients with brain lesions, across the range of pathologies included in our population and independent of symptoms chronicity. Our findings suggest that GLM analysis may be more susceptible to brain activity perturbations induced by a variety of lesions or scanner induced artifacts due to motion or other factors. In our research, we demonstrated that ICA is able to provide fMRI results that can be used in surgery taking into account patient and task wise aspects that differ to those when fMRI is used in research.