Raffaella Franciotti

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We studied MEG and fMRI responses to electric median and tibial nerve stimulation in five healthy volunteers. The aim was to compare the results with those of a previous study using only fMRI on the primary and secondary somatosensory cortices in which the somatotopic organization of SII was observed with fMRI. In the present work we focus on the comparison(More)
Dichotic listening (DL) is a neuropsychological technique for the study of functional laterality. Based on behavioral patient studies, the "structural theory" states that lateralization of the auditory input during DL is allowed by an inhibition of the ipsilateral pathways. We aimed here at extending this theory to provide a neurophysiological basis of(More)
In this MEG study, we investigated cortical alpha/sigma and beta ERD/ERS induced by median nerve stimulation to extend previous evidence on different resonant and oscillatory behavior of SI and SII (NeuroImage 13 [2001] 662). Here, we tested whether simple somatosensory stimulation could induce a distinctive sequence of alpha/sigma and beta ERD/ERS over SII(More)
The secondary somatosensory cortex (SII) is strongly involved in the processing of somatosensory tactile and nociceptive sensations. We investigated the effect on SII responses of simultaneous painful and nonpainful electrical stimulations delivered to the thumb and little finger. According to the "bimodal" (i.e., nociceptive, tactile) organization of SII,(More)
In this MEG study we investigated the differences in responses to somatosensory electrical stimuli between primary (SI) and secondary (SII) sensory cortices using 10 different levels of stimulus intensity, starting from below the sensory threshold up to a weak painful level. SI dipole source linearly increased in amplitude as the stimulus intensity raised(More)
The primary somatosensory cortex (SI) exhibits a detailed topographic organization of the hand and fingers, which has been found to undergo plastic changes following modifications of the sensory input. Although the spatial properties of these changes have been extensively investigated, little is known about their temporal dynamics. In this study, we adapted(More)
The major limitation for the acquisition of high-quality magnetoencephalography (MEG) recordings is the presence of disturbances of physiological and technical origins: eye movements, cardiac signals, muscular contractions, and environmental noise are serious problems for MEG signal analysis. In the last years, multi-channel MEG systems have undergone rapid(More)
AIMS OF THE STUDY Earlier P300 studies were conducted when the prevalence of dementia with Lewy Bodies (DLB) was unknown. Our study aims to examine whether P300 abnormalities are present in DLB and to evidence possible differences between DLB and Alzheimer's disease (AD). A second aim of this study is to look for correlations between P300 recordings and(More)
The present study evaluated the reactivity of cortical rhythms in 15 Alzheimer's disease (AD) patients, 7 Lewy body dementia (LBD) patients and 9 control subjects using a 165 SQUID whole-head MEG system. The absolute power values of the rhythms recorded over different areas over the brain (frontal, parietal, temporal, occipital) were analysed in the 3-47Hz(More)
Default mode network resting state activity in posterior cingulate cortex is abnormally reduced in Alzheimer disease (AD) patients. Fluctuating cognition and electroencephalogram abnormalities are established core and supportive elements respectively for the diagnosis of dementia with Lewy bodies (DLB). Our aim was to assess whether patients with DLB with(More)