Research at CCS fMRI

The Clinical and Experimental Center for Functional Magnetic Resonance Imaging (CCS-fMRI) was set up in 2004, the result of a partnership between the Department of Psychology of the University of Turin and the Neuroradiology Department of the Koelliker Hospital in Turin. As a research facility it is also part of the Interdepartmental Center for Advanced Studies in Neuroscience of the University of Turin (NIT - Neuroscience Institute of Turin), and the Center for Molecular Imaging of the University of Turin (CIM). The CCS-fMRI is dedicated to clinical and experimental neuroscience research. Its goal is to develop protocols for investigating brain connectivity using functional magnetic resonance imaging, as the basis for heuristics and practical guidelines.

Up until now, our research projects using the 1.5 Tesla fMRI scanner at the Koelliker Hospital have mainly been concerned with functional assessments of brain-damaged patients and the evaluation of the effectiveness of rehabilitation therapy. These research projects have attracted funding from various institutions and foundations and led to a number of scientific publications (see below). Members of the fMRI research team from the Koelliker Hospital also use our findings as the subject of their lectures given at the University of Turin and at credit courses offered by other institutions as part of the “Educazione Continua in Medicina” (Continuing Medical Education) program run by the Italian Ministry of Health. Our research projects and training activities for members of the fMRI research team are made possible thanks to our partnerships with national and international clinics and research centers. Our international partners include:

• Cognitive and Affective Neuroscience Laboratory, Tilburg University, The Netherlands
• Maastricht Brain Imaging Center, Department of Cognitive Neuroscience, Maastricht University, The Netherlands
• Institute of Neurology, University College London, London, UK

The university coordinator is Prof. Giuliano Geminiani, Professor of Clinical Neuropsychology at the Department of Psychology, University of Turin. The hospital coordinator is Dr. Sergio Duca, head of the Neuroradiology Unit at the Koelliker Hospital in Turin.

We use both anatomical and functional magnetic resonance imaging techniques. Anatomical techniques include morphometric analysis to measure cortical volume and thickness (in particular, Voxel-Based Morphometry, VBM), and Diffusion Tensor Imaging (DTI) to study the axonal bands and anatomical connectivity. As regards functional techniques, we use functional magnetic resonance imaging (fMRI) to investigate activation, functional connectivity techniques such as seed voxel correlation and Independent Component Analysis (ICA), and effective connectivity methods such as Granger Causality Models (GCM), Structural Equation Models (SEM) and Dynamic Causal Models (DCM). By way of example, some of the functional magnetic resonance imaging techniques in which we have expertise are described in more detail below. Functional magnetic resonance imaging using activation paradigms. - Motor paradigms for the upper limbs (flexion and extension of the fingers; finger tapping); for the lower limbs (dorsiflexion of the ankle, dorsiflexion of the toes); for tongue movement. The ankle dorsiflexion test, in particular, is used to investigate the brain areas involved in gait. This is useful for diagnosis and for evaluating the effectiveness of walking rehabilitation programs. Engineers from the Department of Mechanical Engineering at Turin Polytechnic have designed and built an apparatus which makes it possible to assess patients with paralysis or plegia, by enabling both active and passive ankle movements during MR imaging. The use of this apparatus, which is capable of adjusting and measuring the force and speed of the movement, also makes it possible to compare the results of pre- and post-therapy tests in patients undergoing rehabilitation training. In specific clinical or experimental circumstances, we use paradigms of motor imagery for movements of the upper limbs or walking movements without their overt execution. In research, the use of such motor paradigms and motor imagery has enabled us to validate protocols for gait analysis which have possible implications for rehabilitation (Sacco et al., 2006; Sacco et al., 2009). - Sensory paradigms (brushing of the index and little fingers) are used to identify the somatosensory representation of the fingers. - Visual paradigms (observation of colored shapes) are used to map visual areas associated with position, form, color. - Language paradigms. Of these, the paradigm we use most consists of creating verbs derived from nouns. We have found this to be the most appropriate paradigm for identifying the frontal and temporal language regions and providing the most accurate measure of hemispheric lateralization. These paradigms are mainly used in pre-surgery evaluations. Working in collaboration with neurosurgery departments we have, in some selected cases, been able to use a language paradigm that had previously been used in resonance imaging, during cortical stimulation of the areas involved in language in patients undergoing awake neurosurgery (for a summary of our work in this field see Spena et al., in press). - Cognitive paradigms are used to explore the brain substrates of various mental processes, such as attention (Amanzio et al., in press), verbal and spatial memory (Caglio et al., 2010; in press), recognition of primary and social emotions through facial and body expressions (Tamietto et al., in preparation). Some neuropsychological tests (e.g. the Benton line orientation test, landmark tasks for analyzing unilateral spatial neglect) are used as research tools in experiments involving specific neurological populations. The motor, sensory, visual and language paradigms are based on a block design, in which the activation condition alternates with a baseline or lation investigated using electroencephalography Another research topic is concerned with the functional significance and modulation of evoked potentials, measured using electroencephalography (EEG). These evoked brain responses are shown as deviations in the EEG reading, and as alterations in brain activity within the specific frequency ranges that characterize spontaneous brain electrical activity (e.g. rhythms α, β, γ) following the administration of stimuli. One aim of our research in this area is to investigate and characterize the influence of attention and cognitive conflict (introduced, for instance, by the assumption of unusual postures, leading to misalignment of spatial and somatotopic maps) on these brain responses and their brain mapping.