Neuroimaging Laboratory

Santa Lucia di Serino, Italy

Neuroimaging Laboratory

Santa Lucia di Serino, Italy

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News Article | September 14, 2016

As far as the brain's craving for nicotine is concerned, a person's perception that the cigarette contains nicotine has a key role to play, reports a research from the Center for BrainHealth at the University of Texas in Dallas. Smokers only feel satisfaction when they believe the cigarette they are smoking contains nicotine, if not even the nicotine cigarettes have no effect on their brain. For the study, the researchers included 24 nicotine addicts in four different experiments conducted on different occasions. In the double blind study, the participants were given real cigarettes with nicotine twice and fake placebo cigarettes twice. The participants were first given a placebo cigarette, but were told that it was a real one. On the second visit they were given a real cigarette, but were informed that they were smoking a fake cigarette. The participants then received a real cigarette, knowing that it was a real one on their third visit, and finally they were given a placebo cigarette and was informed that it's a fake one. The investigators used functional magnetic resonance imaging (fMRI) to monitor the neural activity in the insula cortex of the participants. Insula cortex is the region of the brain that controls certain functions of a person including self-awareness and perceptions. This region plays an important role in issues like drug addiction and craving. The participants were subjected to fMRI every time after smoking the cigarette and were also asked to complete a reward learning task. The subjects were also asked to rate their nicotine craving levels before and after every experiment. The fMRI showed significant neural activity when the participants smoked real cigarettes knowing that it contained nicotine. The fMRI results also correlated with both craving and learning signals during the task. However, the participants did not have the same neural activity in the brain when they smoked real cigarette believing that it was a fake one. The study outcome supports several previous findings that said beliefs have a role to play in the effect of drugs on issues like craving and addiction. "We expected the presence of nicotine to show some sort of craving response compared to conditions where the subjects did not receive nicotine despite the belief about the nicotine given, but that was not what we found," said Read Montague, the study's co-author and director of the Human Neuroimaging Laboratory and the Computational Psychiatry Unit at Virginia Tech Carilion Research Institute. The study is published online in the journal Frontiers in Psychiatry. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.

Bueti D.,University College London | Bueti D.,Neuroimaging Laboratory | Walsh V.,University College London
Perception | Year: 2010

Our experience of time is unlike that of other features of the sensory world such as colour, movement, touch, or sound because there is no unique receptor system through which it is received. However, since time can be perceived, remembered, estimated, and compared in a way analogous to other sensory experiences, it should perhaps be subject to some of the same architectures or principles that have advanced understanding in these other domains. By adapting a task designed to test visual memory within a perception/action framework we investigated whether memory for time is affected by the use to which temporal information is put. When remembering a visual or auditory duration for subsequent motor production, storage is biased by a delay of up to 8 s. When the same duration is remembered for subsequent perception, however, there is no such effect of delay on memory. The results suggest a distinction in temporal memory that parallels the perception/action dichotomy in vision. © 2010 a Pion publication.

Borroni B.,University of Brescia | Premi E.,University of Brescia | Bozzali M.,Neuroimaging Laboratory | Padovani A.,University of Brescia
Current Medicinal Chemistry | Year: 2012

In the course of neurodegenerative disorders there are several mechanisms that may counteract the pathological process, mitigating the clinical manifestations of the disease. Usually referred as cognitive reserve hypothesis, this theoretical framework posits that individuals with enriched cognitive status (i.e. with higher educational and occupational levels and higher individual social achievement) may cope better with the occurrence of cognitive decline by a more efficient recruitment of neural networks sustaining higher-level functions. Cognitive reserve was initially studied in Alzheimer's disease, but this concept has been soon after extended also to other neurodegenerative disorders, such as Frontotemporal Dementia, Parkinson's disease, and Huntington's disease, suggesting a general applicability of cortical plasticity phenomena in contrasting neurodegeneration. The neural underpinnings of these dynamic compensatory mechanisms open the possibility for strategic interventions based on environmental approaches. In this continuously growing field, the aim of the present review is to explore new acquisitions, derived from basic research and clinical grounds, on cognitive reserve mechanisms and the potential application as novel therapeutic targets in neurodegenerative diseases. © 2012 Bentham Science Publishers.

Nardo D.,Neuroimaging Laboratory | Hogberg G.,Karolinska Institutet | Looi J.C.L.,Australian National University | Larsson S.,Karolinska University Hospital | And 3 more authors.
Journal of Psychiatric Research | Year: 2010

There is converging evidence of gray matter (GM) structural alterations in different limbic structures in Post-Traumatic Stress Disorder (PTSD) patients. The aim of this study was to evaluate GM density in PTSD in relation to trauma load, and to assess the GM differences between responders (R) and non-responders (NR) to EMDR therapy. Magnetic Resonance Imaging (MRI) scans of 21 subjects exposed to occupational trauma, who developed PTSD (S), and of 22 who did not (NS), were compared by means of an optimized Voxel-Based Morphometry (VBM) analysis as implemented in SPM. Within S, further comparisons were made between 10 R and 5 NR. A regression analysis between GM density and the Traumatic Antecedents Questionnaire (TAQ) was also performed on all 43 subjects. Results showed a significantly lower GM density in S as compared to NS in the left posterior cingulate and the left posterior parahippocampal gyrus. Moreover, NR showed a significantly lower GM density as compared to R in bilateral posterior cingulate, as well as anterior insula, anterior parahippocampal gyrus and amygdala in the right hemisphere. Regression analysis showed that GM density negatively correlated with trauma load in bilateral posterior cingulate, left anterior insula, and right anterior parahippocampal gyrus. In conclusion, a GM lower density in limbic and paralimbic cortices were found to be associated with PTSD diagnosis, trauma load, and EMDR treatment outcome, suggesting a view of PTSD characterized by memory and dissociative disturbances. © 2009 Elsevier Ltd.

Macaluso E.,Neuroimaging Laboratory
Cortex | Year: 2010

Many everyday situations require combining complex sensory signals about the external world with ongoing goals and expectations. Here I examine the role of attention in this process and consider the underling neural substrates. First, mechanisms of spatial attention in the visual modality are reviewed, emphasising the involvement of fronto-parietal cortex. Spatial attention takes into account endogenous factors, e.g., information about behavioural relevance, as well as signals arising from the external world (stimulus-driven control). Stimulus-driven control is thought to take place automatically and independently from endogenous factors. However, recent findings demonstrate that endogenous and stimulus-driven mechanisms co-operate, jointly contributing for the selection of the relevant spatial location. Next, I will turn to studies of multisensory spatial attention. These have shown that attention control in fronto-parietal cortex operates supramodally. Supramodal control exerts top-down influences onto sensory-specific areas, enhancing the processing of stimuli at the attended location irrespective of modality. Unlike unimodal visual attention, but in line with traditional views of multisensory integration, multisensory attention can operate in a fully automatic manner regardless of relevance and task-set. I discuss these findings in relation to functional/anatomical pathways that may mediate multisensory attention control, highlighting possible links between spatial attention and multisensory integration of space. © 2009 Elsevier Srl.

Knyazeva M.G.,University of Lausanne | Jalili M.,Sharif University of Technology | Frackowiak R.S.,University of Lausanne | Frackowiak R.S.,Neuroimaging Laboratory | Rossetti A.O.,University of Lausanne
Journal of Neurology, Neurosurgery and Psychiatry | Year: 2011

Objective Psychogenic non-epileptic seizures (PNES) are paroxysmal events that, in contrast to epileptic seizures, are related to psychological causes without the presence of epileptiform EEG changes. Recent models suggest a multifactorial basis for PNES. A potentially paramount, but currently poorly understood factor is the interplay between psychiatric features and a specific vulnerability of the brain leading to a clinical picture that resembles epilepsy. Hypothesising that functional cerebral network abnormalities may predispose to the clinical phenotype, the authors undertook a characterisation of the functional connectivity in PNES patients. Methods The authors analysed the whole-head surface topography of multivariate phase synchronisation (MPS) in interictal high-density EEG of 13 PNES patients as compared with 13 age- and sex-matched controls. MPS mapping reduces the wealth of dynamic data obtained from high-density EEG to easily readable synchronisation maps, which provide an unbiased overview of any changes in functional connectivity associated with distributed cortical abnormalities. The authors computed MPS maps for both Laplacian and common-averagereference EEGs. Results In a between-group comparison, only patchy, non-uniform changes in MPS survived conservative statistical testing. However, against the background of these unimpressive group results, the authors found widespread inverse correlations between individual PNES frequency and MPS within the prefrontal and parietal cortices. Interpretation PNES appears to be associated with decreased prefrontal and parietal synchronisation, possibly reflecting dysfunction of networks within these regions.

Lenzi D.,University of Rome La Sapienza | Trentini C.,University of Rome La Sapienza | Pantano P.,University of Rome La Sapienza | Macaluso E.,Neuroimaging Laboratory | And 2 more authors.
Human Brain Mapping | Year: 2013

Background: The attachment model, as assessed by means of the Adult Attachment Interview (AAI), is crucial for understanding emotion regulation and feelings of security in human interactions as well as for the construction of the caregiving system. The caregiving system is a set of representations about affiliative behaviors, guided by sensitivity and empathy, and is fully mature in young-adulthood. Here, we examine how different attachment models influence brain responses in areas related to empathy and emotions in young-adult subjects with secure and dismissing attachment models. Methods: By means of AAI, we selected 11 nulliparous young-adult females with a secure model and 12 with a dismissing model. Subjects underwent functional magnetic resonance, whereas imitating or observing and empathizing with infant facial expressions. Subjects were tested for alexithymia and reflective functioning. Results: Dismissing subjects activated motor, mirror, and limbic brain areas to a significantly greater extent, but deactivated the medial orbitofrontal cortex (mOFC) and the perigenual anterior cingulated cortex (pACC). During emotional faces, increased activity in dismissing women was seen in the right temporal pole. Furthermore, greater alexithymia was correlated with greater activity in the entorhinal cortex and greater deactivation in the pACC/mOFC. Conclusions: These findings provide evidence of how the attachment model influences brain responses during a task eliciting attachment. In particular, hyperactivation of limbic and mirror areas may reflect emotional dysregulation of infantile experiences of rejection and lack of protection, whereas increased deactivation of fronto-medial areas may be the expression of the inhibition of attachment behaviors, which is a typical aspect of dismissing attachment. © 2012 Wiley Periodicals, Inc.

Nardo D.,Neuroimaging Laboratory | Santangelo V.,Neuroimaging Laboratory | Santangelo V.,University of Perugia | Macaluso E.,Neuroimaging Laboratory
Human Brain Mapping | Year: 2014

Previous studies on crossmodal spatial orienting typically used simple and stereotyped stimuli in the absence of any meaningful context. This study combined computational models, behavioural measures and functional magnetic resonance imaging to investigate audiovisual spatial interactions in naturalistic settings. We created short videos portraying everyday life situations that included a lateralised visual event and a co-occurring sound, either on the same or on the opposite side of space. Subjects viewed the videos with or without eye-movements allowed (overt or covert orienting). For each video, visual and auditory saliency maps were used to index the strength of stimulus-driven signals, and eye-movements were used as a measure of the efficacy of the audiovisual events for spatial orienting. Results showed that visual salience modulated activity in higher-order visual areas, whereas auditory salience modulated activity in the superior temporal cortex. Auditory salience modulated activity also in the posterior parietal cortex, but only when audiovisual stimuli occurred on the same side of space (multisensory spatial congruence). Orienting efficacy affected activity in the visual cortex, within the same regions modulated by visual salience. These patterns of activation were comparable in overt and covert orienting conditions. Our results demonstrate that, during viewing of complex multisensory stimuli, activity in sensory areas reflects both stimulus-driven signals and their efficacy for spatial orienting; and that the posterior parietal cortex combines spatial information about the visual and the auditory modality. © 2013 Wiley Periodicals, Inc.

Prosperini L.,University of Rome La Sapienza | Sbardella E.,University of Rome La Sapienza | Raz E.,University of Rome La Sapienza | Cercignani M.,Neuroimaging Laboratory | And 5 more authors.
Radiology | Year: 2013

Purpose: To combine two unbiased (ie, without any a priori hypothesis) magnetic resonance (MR) imaging processing approaches, tract-based spatial statistics and voxel-based morphometry, to investigate the relationship between white matter and gray matter damage and computerbased measures of balance impairment assessed at static posturography in patients with multiple sclerosis (MS). Materials and Methods: Institutional review board approval and written informed consent were obtained. Forty-five ambulatory patients with MS (34 women, 11 men) and 25 sex-and agematched healthy control subjects were assessed by using a force platform to compute the displacement (in millimeters) of the body center of pressure in 30 seconds. In a separate session, patients underwent MR imaging at 3 T, including a dual-echo fast spin-echo sequence, a T1-weighted volume sequence, and a diffusion-tensor imaging sequence. T2 lesion volumes were assessed by using a semiautomated technique. Tract-based spatial statistics and voxel-based morphometry were used for the white and gray matter analyses, respectively, to correlate force platform measures with diffusion-tensor imaging parameters and regional gray matter volumes, adjusting for the patients' sex, age, disease duration, and lesion volume. Results: Patients with MS had worse postural stability, widespread alterations in most white matter bundles, and gray matter atrophy in several brain regions compared with control subjects. In patients with MS, balance impairment was correlated with worse diffusion-tensor imaging parameters along the cerebellar connections and supratentorial associative white matter bundles (P , .05, threshold-free cluster enhancement corrected). Gray matter atrophy of the superior lobules of the cerebellum (IV, V, VI), and lobules VIII also correlated with worse posturometric values (P , .05, family-wise error corrected). Conclusion: Imbalance due to MS appears to be related to the disconnection between the spinal cord, cerebellum, and cerebral cortex, which in turn produces atrophy of the sensory motor cerebellar regions that are functionally connected with specific cortical areas. © RSNA, 2013.

Santangelo V.,University of Perugia | Santangelo V.,Neuroimaging Laboratory | Macaluso E.,Neuroimaging Laboratory
Human Brain Mapping | Year: 2013

Previous studies have indicated that increasing working memory (WM) load can affect the attentional selection of signals originating from one object/location. Here we assessed whether WM load affects also the selection of multiple objects/locations (divided attention). Participants monitored either two object-categories (vs. one category; object-based divided attention) or two locations (vs. one location; space-based divided attention) while maintaining in WM either a variable number of objects (object-based WM load) or locations (space-based WM load). Behavioural results showed that WM load affected attentional performance irrespective of divided or focused attention. However, fMRI results showed that the activity associated with object-based divided attention increased linearly with increasing object-based WM load in the left and right intraparietal sulcus (IPS); while, in the same areas, activity associated with space-based divided attention was not affected by any type of WM load. These findings support the hypothesis that WM contributes to the maintenance of resource-demanding attentional sets in a domain-specific manner. Moreover, the dissociable impact of WM load on performance and brain activity suggests that increased IPS activation reflects a recruitment of additional, domain-specific processing resources that enable dual-task performance under conditions of high WM load and high attentional demand. © 2011 Wiley Periodicals, Inc.

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