Posture used in fMRI-PET elicits reduced cortical activity and altered hemispheric asymmetry with respect to sitting position: An EEG resting state study

Horizontal body position is a posture typically adopted for sleeping or during brain imaging recording in both neuroscience experiments and diagnostic situations. Recent literature showed how this position and similar ones with head down are associated to reduced plasticity, impaired pain and emotional responses. The present study aimed at further understanding the decrease of cortical activity associated with horizontal body position by measuring high-frequency EEG bands \u2013 typically associated with high-level cognitive activation \u2013 in a resting state experimental condition. To this end, two groups of 16 female students were randomly assigned to either sitting control (SC) or 2-h horizontal Bed Rest condition (hBR) while EEG was recorded from 38 scalp recording sites. The hBR group underwent several body transitions, from sitting to supine, and from supine to sitting. Results revealed a clear effect of horizontal posture: the hBR group showed, compared to its baseline and to SC, reduced High-Beta and Gamma EEG band amplitudes throughout the 2-h of hBR condition. In addition, before and after the supine condition, hBR group as well as SC exhibited a greater left vs. right frontal activation in both EEG bands while, on the contrary, the supine position induced a bilateral and reduced activation in hBR participants. The cortical sources significantly more active in SC compared with hBR participants included the left Inferior Frontal Gyrus and left Insula. Results are discussed in relation to the differences among neuroimaging methods (e.g., fMRI, EEG, NIRS), which can be partially explained by posture-induced neural network changes

Brain plasticity in aphasic patients: Intra- and inter-hemispheric reorganisation of the whole linguistic network probed by N150 and N350 components

The present study examined linguistic plastic reorganization of language through Evoked Potentials in a group of 17 non-fluent aphasic patients who had suffered left perisylvian focal lesions, and showed a good linguistic recovery. Language reorganisation was probed with three linguistic tasks (Phonological, Semantic, Orthographic), the early word recognition potential (N150) and the later phonological-related component (N350). Results showed the typical left-lateralised posterior N150 in healthy controls (source: left Fusiform Gyrus), that was bilateral (Semantic) or right sided (Phonological task) in patients (sources: right Inferior/Middle Temporal and Fusiform Gyri). As regards N350, controls revealed different intra- and inter-hemispheric linguistic activation across linguistic tasks, whereas patients exhibited greater activity in left intact sites, anterior and posterior to the damaged area, in all tasks (sources: Superior Frontal Gyri). A comprehensive neurofunctional model is presented, describing how complete intra- and inter-hemispheric reorganisation of the linguistic networks occurs after aphasic damage in the strategically dominant left perisylvian linguistic centres

Informative models of cultural heritage: the "unfinished" church of Brendola

The paper is an initial form of dissemination of the research activities carried out by the Universit\ue0 Iuav di Venezia working group which, on behalf of the Municipal administration of Brendola, seeks to delineate the application of a methodology for the study and analysis of the architectural and landscape heritage of significant cultural interest that is in a state of abandonment. The case study application is the church of San Michele Arcangelo in Brendola (Vicenza), known as the \u201cIncompiuta\u201d (\u201cUnfinished\u201d). The case study proposed is an interesting exemplar of ecclesiastical architecture, designed by engineer-architect Fausto Franco, in which its characteristics of being unfinished and in a state of ruin contribute to redefining the image of a work that fits in a historical context of architectural and technical experimentation, where the reference to historical architecture is mediated by contemporary forms and by the use of modern building materials, among which, the use of reinforced bricks is noteworthy. The research activity, which is taking place in the context of the COVID-19 health emergency, aims at putting a series of strategies and operational practices based on the digitisation of data to the test to allow increased interoperability and sharing through the building of an online open data repository addressed to the actors involved in the conservation process and to the community. In the processes of conservation and valorisation, in-depth knowledge and documentation of the materials and construction techniques involve multidisciplinary areas; effectively organising them in a system that regulates their collection, cataloguing, processing and archiving according to shared procedures, therefore becomes a fundamental prerequisite for the development of operational planning of the valorisation strategies. All the instruments that make it possible to collect data and reach true knowledge of the object become indispensable. From this perspective, the push towards digitising the data that emerged during the pandemic phase plays a fundamental role in the range of application possibilities, from the survey to the mechanisms for the conservation and management of cultural heritage

Multi-tasking uncovers right spatial neglect and extinction in chronic left-hemisphere stroke patients

open7noUnilateral Spatial Neglect, the most dramatic manifestation of contralesional space unawareness, is a highly heterogeneous syndrome. The presence of neglect is related to core spatially lateralized deficits, but its severity is also modulated by several domain-general factors (such as alertness or sustained attention) and by task demands. We previously showed that a computer-based dual-task paradigm exploiting both lateralized and non-lateralized factors (i.e., attentional load/multitasking) better captures this complex scenario and exacerbates deficits for the contralesional space after right hemisphere damage. Here we asked whether multitasking would reveal contralesional spatial disorders in chronic left hemisphere damaged (LHD) stroke patients, a population in which impaired spatial processing is thought to be uncommon. Ten consecutive LHD patients with no signs of right-sided neglect at standard neuropsychological testing performed a computerized spatial monitoring task with and without concurrent secondary tasks (i.e., multitasking). Severe contralesional (right) space unawareness emerged in most patients under attentional load in both the visual and auditory modalities. Multitasking affected the detection of contralesional stimuli both when presented concurrently with an ipsilesional one (i.e., extinction for bilateral targets) and when presented in isolation (i.e., left neglect for right-sided targets). No spatial bias emerged in a control group of healthy elderly participants, who performed at ceiling, as well as in a second control group composed of patients with Mild Cognitive Impairment. We conclude that the pathological spatial asymmetry in LHD patients cannot be attributed to a global reduction of cognitive resources but it is the consequence of unilateral brain damage. Clinical and theoretical implications of the load-dependent lack of awareness for contralesional hemispace following LHD are discussed.embargoed_20180601Blini, Elvio; Romeo, Zaira; Spironelli, Chiara; Pitteri, Marco; Meneghello, Francesca; Bonato, Mario; Zorzi, MarcoBlini, ELVIO ADALBERTO; Romeo, Zaira; Spironelli, Chiara; Pitteri, Marco; Meneghello, Francesca; Bonato, Mario; Zorzi, Marc

Evidence of language-related left hypofrontality in Major Depression: An EEG Beta band study

Major depression (MDD) has been associated with an altered EEG frontal asymmetry measured in resting state; nevertheless, this association has showed a weak consistency across studies. In the present study, which starts from an evolutionistic view of psychiatric disorders, we investigated frontal asymmetry in MDD, using language as a probe to test the integrity of large inter- and intra-hemispheric networks and processes. Thirty MDD patients (22 women) and 32 matched controls (HC) were recruited for an EEG recording in resting state and during two linguistic tasks, phonological and semantic. Normalized alpha and beta EEG spectral bands were measured across all three conditions in the two groups. EEG alpha amplitude showed no hemispheric asymmetry, regardless of group, both at rest and during linguistic tasks. During resting state, analysis of EEG beta revealed a lack of hemispheric asymmetry in both groups, but during linguistic tasks, HC exhibited the typical greater left frontal beta activation, whereas MDD patients showed a lack of frontal asymmetry and a significantly lower activation of left frontal sites. In depressed patients, positive affect was negatively correlated with depression levels and positively correlated with left frontal EEG beta amplitude. Language represents the human process that requires the largest level of integration between and within the hemispheres; thus, language asymmetry was a valid probe to test the left frontal alteration encompassing highly impairing psychiatric disorders, such as schizophrenia and MDD. Indeed, these severe diseases are marked by delusions, ruminations, thought disorders, and hallucinations, all of which have a clear linguistic or metalinguistic basis

Print-Tuning Lateralization and Handedness:An Event-Related Potential Study in Dyslexic Higher Education Students

Despite their ample reading experience, higher education students with dyslexia still show deficits in reading and reading-related skills. Lateralized print tuning, the early sensitivity to print of the left parietal cortex signalled by the N1 event-related potential (ERP) component, differs between beginning dyslexic readers and controls. For adults, the findings are mixed. The present study aims to investigate whether print tuning, as indexed by the N1 component, differs between 24 students with dyslexia and 15 non-dyslexic controls. Because handedness has been linked to lateralization, first, a separate analysis was conducted including only right-handed participants (n=12 in both groups), like in most previous studies. ERPs were measured during a judgement task, requiring visual, phonological, or semantic judgments. In both groups, the N1 was earlier and stronger in the left than in the right hemisphere. However, when only strongly right-handed participants were evaluated, the N1 was less left-lateralized for participants with dyslexia as compared with controls. Participants with dyslexia had longer reaction times during the ERP experiment and performed worse on many reading (-related) tasks. These findings suggest that abnormal print tuning can still be found among higher education students with dyslexia and that handedness should be regarded in the study of print tuning. Copyright (c) 2015 John Wiley & Sons, Ltd

Effects of Multimodal Load on Spatial Monitoring as Revealed by ERPs

While the role of selective attention in filtering out irrelevant information has been extensively studied, its characteristics and neural underpinnings when multiple environmental stimuli have to be processed in parallel are much less known. Building upon a dual-task paradigm that induced spatial awareness deficits for contralesional hemispace in right hemisphere-damaged patients, we investigated the electrophysiological correlates of multimodal load during spatial monitoring in healthy participants. The position of appearance of briefly presented, lateralized targets had to be reported either in isolation (single task) or together with a concurrent task, visual or auditory, which recruited additional attentional resources (dual-task). This top-down manipulation of attentional load, without any change of the sensory stimulation, modulated the amplitude of the first positive ERP response (P1) and shifted its neural generators, with a suppression of the signal in the early visual areas during both visual and auditory dual tasks. Furthermore, later N2 contralateral components elicited by left targets were particularly influenced by the concurrent visual task and were related to increased activation of the supramarginal gyrus. These results suggest that the right hemisphere is particularly affected by load manipulations, and confirm its crucial role in subtending automatic orienting of spatial attention and in monitoring both hemispaces

Influence of Body Position on Cortical Pain-Related Somatosensory Processing: An ERP Study

Background: Despite the consistent information available on the physiological changes induced by head down bed rest, a condition which simulates space microgravity, our knowledge on the possible perceptual-cortical alterations is still poor. The present study investigated the effects of 2-h head-down bed rest on subjective and cortical responses elicited by electrical, pain-related somatosensory stimulation. Methodology/Principal Findings: Twenty male subjects were randomly assigned to two groups, head-down bed rest (BR) or sitting control condition. Starting from individual electrical thresholds, Somatosensory Evoked Potentials were elicited by electrical stimuli administered randomly to the left wrist and divided into four conditions: control painless condition, electrical pain threshold, 30 % above pain threshold, 30 % below pain threshold. Subjective pain ratings collected during the EEG session showed significantly reduced pain perception in BR compared to Control group. Statistical analysis on four electrode clusters and sLORETA source analysis revealed, in sitting controls, a P1 component (40–50 ms) in the right somatosensory cortex, whereas it was bilateral and differently located in BR group. Controls ’ N1 (80–90 ms) had widespread right hemisphere activation, involving also anterior cingulate, whereas BR group showed primary somatosensory cortex activation. The P2 (190–220 ms) was larger in left-central locations of Controls compared with BR group. Conclusions/Significance: Head-down bed rest was associated to an overall decrease of pain sensitivity and an altered pai

Orienting Attention Modulates Pain Perception: An ERP Study

2011-2012 > Academic research: refereed > Publication in refereed journalpublished_fina