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Bonino D.,University of Pisa | Ricciardi E.,University of Pisa | Ricciardi E.,MRI Laboratory | Bernardi G.,University of Pisa | And 5 more authors.
Neuropsychologia | Year: 2015

Although vision offers distinctive information to space representation, individuals who lack vision since birth often show perceptual and representational skills comparable to those found in sighted individuals. However, congenitally blind individuals may result in impaired spatial analysis, when engaging in 'visual' spatial features (e.g., perspective or angle representation) or complex spatial mental abilities. In the present study, we measured behavioral and brain responses using functional magnetic resonance imaging in sighted and congenitally blind individuals during spatial imagery based on a modified version of the mental clock task (e.g., angle discrimination) and a simple recognition control condition, as conveyed across distinct sensory modalities: visual (sighted individuals only), tactile and auditory. Blind individuals were significantly less accurate during the auditory task, but comparable-to-sighted during the tactile task. As expected, both groups showed common neural activations in intraparietal and superior parietal regions across visual and non-visual spatial perception and imagery conditions, indicating the more abstract, sensory independent functional organization of these cortical areas, a property that we named supramodality. At the same time, however, comparisons in brain responses and functional connectivity patterns across experimental conditions demonstrated also a functional lateralization, in a way that correlated with the distinct behavioral performance in blind and sighted individuals. Specifically, blind individuals relied more on right parietal regions, mainly in the tactile and less in the auditory spatial processing. In sighted, spatial representation across modalities relied more on left parietal regions. In conclusions, intraparietal and superior parietal regions subserve supramodal spatial representations in sighted and congenitally blind individuals. Differences in their recruitment across non-visual spatial processing in sighted and blind individuals may be related to distinctive behavioral performance and/or mental strategies adopted when they deal with the same spatial representation as conveyed through different sensory modalities. © 2015 Elsevier Ltd.

Todiere G.,University of Pisa | Todiere G.,MRI Laboratory | Marzilli M.,University of Pisa
Minerva Cardioangiologica | Year: 2012

Heart failure is the leading cause of mortality and rehospitalization in Western countries. With the development of new technologies applied to medical diagnostic pathways, cardiovascular imaging has rapidly gained ground. Therefore, the clinical cardiologist has to keep updated on the management of such innovative diagnostic tools which were once the exclusive domain of radiologists. The need to understand a new language is fundamental for the selection of diagnostic and therapeutic strategies in patients with heart failure, which is often the final destination for many cardiovascular diseases. Alongside standard diagnostic techniques such as chest radiography two-dimensional ultrasound and cardiac color Doppler, all of which are indispensable in daily practice, innovative tools have been defining their incremental role in cardiovascular imaging. Cardiac magnetic resonance (CMR), cardiac computed tomography (CT), speckle tracking, 3D echocardiography, new applications in nuclear medicine (SPECT MIBG), and "cardiac hybrid imaging" are emerging for research and are also playing a pivotal role in the clinical scenario. These techniques are useful the for non-invasive acquisition of diagnostic and prognostic information in heart failure. Whether the radiological and economic impact of diese new technologies is sustainable is a question the clinical cardiologist will need to answer when considering the cost/benefit of the diagnostic tool selected among diese methods.

Kulinski R.,MRI Laboratory | Bauminger E.R.,Hebrew University of Jerusalem | Friedman A.,Medical University of Warsaw | Duda P.,Warsaw University of Technology | Galazka-Friedman J.,Warsaw University of Technology
Hyperfine Interactions | Year: 2016

Iron may play important role in neurodegeneration. The results of comparative studies of human brain areas (control and pathological) performed by Mössbauer spectroscopy (MS) and magnetic resonance imaging (MRI) techniques are presented. Mössbauer spectroscopy demonstrated a higher concentration of iron in atypical parkinsonism (progressive supranuclear palsy PSP) in the brain areas Substantia Nigra (SN) and Globus Pallidus (GP) involved in this pathological process, compared to control, while the concentration of iron in pathological tissues in typical parkinsonism (Parkinson’s disease - PD) did not differ from that in control. These results were compared with the changes in 1/T1 and 1/T2 (T1 and T2 being the relaxation times determined by MRI). A good linear correlation curve was found between the concentration of iron as determined by MS in different areas of control human brains and between 1/T1 and 1/T2. Whereas the finding in PSP-GP (the brain area involved in PSP) also fitted to such a correlation, this was not so for the correlation between pathological SN – the brain area involved in both diseases – and 1/T2, indicating a dependence of T2 on other factors than just the concentration of iron. © 2016, The Author(s).

Ricciardi E.,University of Pisa | Ricciardi E.,MRI Laboratory | Handjaras G.,University of Pisa | Bonino D.,University of Pisa | And 5 more authors.
PLoS ONE | Year: 2013

The representation of actions within the action-observation network is thought to rely on a distributed functional organization. Furthermore, recent findings indicate that the action-observation network encodes not merely the observed motor act, but rather a representation that is independent from a specific sensory modality or sensory experience. In the present study, we wished to determine to what extent this distributed and 'more abstract' representation of action is truly supramodal, i.e. shares a common coding across sensory modalities. To this aim, a pattern recognition approach was employed to analyze neural responses in sighted and congenitally blind subjects during visual and/or auditory presentation of hand-made actions. Multivoxel pattern analyses-based classifiers discriminated action from non-action stimuli across sensory conditions (visual and auditory) and experimental groups (blind and sighted). Moreover, these classifiers labeled as 'action' the pattern of neural responses evoked during actual motor execution. Interestingly, discriminative information for the action/non action classification was located in a bilateral, but left-prevalent, network that strongly overlaps with brain regions known to form the action-observation network and the human mirror system. The ability to identify action features with a multivoxel pattern analyses-based classifier in both sighted and blind individuals and independently from the sensory modality conveying the stimuli clearly supports the hypothesis of a supramodal, distributed functional representation of actions, mainly within the action-observation network. © 2013 Ricciardi et al.

Tomaiuolo F.,Volterra | Campana S.,University of Padua | Collins D.L.,Montreal Neurological Institute | Fonov V.S.,Montreal Neurological Institute | And 8 more authors.
PLoS ONE | Year: 2014

We examined the effects of visual deprivation at birth on the development of the corpus callosum in a large group of congenitally blind individuals. We acquired high-resolution T1-weighted MRI scans in 28 congenitally blind and 28 normal sighted subjects matched for age and gender. There was no overall group effect of visual deprivation on the total surface area of the corpus callosum. However, subdividing the corpus callosum into five subdivisions revealed significant regional changes in its three most posterior parts. Compared to the sighted controls, congenitally blind individuals showed a 12% reduction in the splenium, and a 20% increase in the isthmus and the posterior part of the body. A shape analysis further revealed that the bending angle of the corpus callosum was more convex in congenitally blind compared to the sighted control subjects. The observed morphometric changes in the corpus callosum are in line with the well-described cross-modal functional and structural neuroplastic changes in congenital blindness. © 2014 Tomaiuolo et al.

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