Mauro Gianni Perrucci
Research interests
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InterestsMRI, Medical Image Processing, Medical Image Analysis, fMRI, DTI, EEG, Functional Magnetic Resonance Imaging, EEG Signal Processing, Neuroimaging, Signal & Image Processing, Signal Analysis, Wavelet Analysis, Signal, Pattern Recognition, Machine Learning, Diffusion Tensor Imaging, Medical Imaging, Image Processing, EEG-Software, EEG/ERP, EEGLAB
Publications
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5.74Impact points
Common and unique neuro-functional basis of induction, visualization, and spatial relationships as cognitive components of fluid intelligence.
NeuroImage. 05/2012;
Neuroimaging research of fluid intelligence (Gf) has mainly focused on the neural basis of abilities explaining performance on cognitive tasks. However, the neuro-functional basis of clearly defined theoretical cognitive components underlying Gf remains unclear. Induction, Visualization, and Spatial... [more] Neuroimaging research of fluid intelligence (Gf) has mainly focused on the neural basis of abilities explaining performance on cognitive tasks. However, the neuro-functional basis of clearly defined theoretical cognitive components underlying Gf remains unclear. Induction, Visualization, and Spatial Relationships have the highest relevance for Gf (Carroll, 1993). Here we report a functional magnetic resonance imaging (fMRI) study exploring the neural correlates of these abilities characterized by their unidimensionality and matched for task-difficulty, as evidenced by a psychometric calibration study. Twenty-two healthy young adult females, recruited from a large sample of 300 participants, with either below- or above-average Gf abilities underwent fMRI scanning during Gf tasks performance. The results reveal that these tasks activate a shared frontoparietal network. Specific activations were also observed, in particular for Induction and Visualization. The key findings suggest that Gf comprises distinguishable cognitive abilities, but the Gf construct is associated with a common network.
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4.88Impact points
The Role of Left Superior Parietal Lobe in Male Sexual Behavior: Dynamics of Distinct Components Revealed by fMRI.
The journal of sexual medicine. 04/2012;
Introduction. Despite the interest for the brain correlates of male sexual arousal, few studies investigated neural mechanisms underlying psychogenic erectile dysfunction (ED). Although these studies showed several brain regions active in ED patients during visual erotic stimulation, the dynamics o... [more] Introduction. Despite the interest for the brain correlates of male sexual arousal, few studies investigated neural mechanisms underlying psychogenic erectile dysfunction (ED). Although these studies showed several brain regions active in ED patients during visual erotic stimulation, the dynamics of inhibition of sexual response is still unclear. Aim. This study investigated the dynamics of brain regions involved in the psychogenic ED. Methods. Functional magnetic resonance imaging (fMRI) and simultaneous penile tumescence (PT) were used to study brain activity evoked in 17 outpatients with psychogenic ED and 19 healthy controls during visual erotic stimulation. Patterns of brain activation related to different phases of sexual response in the two groups were compared. Main Outcome Measures. Simultaneous recording of blood oxygen level-dependent fMRI responses and PT during visual erotic stimulation. Results. During visual erotic stimuli, a larger activation was observed for the patient group in the left superior parietal lobe, ventromedial prefrontal cortex, and posterior cingulate cortex, whereas the control group showed larger activation in the right middle insula and dorsal anterior cingulate cortex and hippocampus. Moreover, the left superior parietal lobe showed a larger activation in patients than controls especially during the later stage of sexual response. Conclusion. Our results suggest that, among regions more active in patient group, the left superior parietal lobe plays a crucial role in inhibition of sexual response. Previous studies showed that left superior parietal lobe is involved in monitoring of internal body representation. The larger activation of this region in patients during later stages of sexual response suggests a high monitoring of the internal body representation, possibly affecting the behavioral response. These findings provide insight on brain mechanisms involved in psychogenic ED. Cera N, Di Pierro ED, Sepede G, Gambi F, Perrucci MG, Merla A, Tartaro A, Del Gratta C, Galatioto Paradiso G, Vicentini C, Romani GL, and Ferretti A. The role of left superior parietal lobe in male sexual behavior: Dynamics of distinct components revealed by fMRI. J Sex Med **;**:**-**.
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16.87Impact points
Interspecies activity correlations reveal functional correspondence between monkey and human brain areas.
Nature methods. 01/2012; 9(3):277-82.
Evolution-driven functional changes in the primate brain are typically assessed by aligning monkey and human activation maps using cortical surface expansion models. These models use putative homologous areas as registration landmarks, assuming they are functionally correspondent. For cases in which... [more] Evolution-driven functional changes in the primate brain are typically assessed by aligning monkey and human activation maps using cortical surface expansion models. These models use putative homologous areas as registration landmarks, assuming they are functionally correspondent. For cases in which functional changes have occurred in an area, this assumption prohibits to reveal whether other areas may have assumed lost functions. Here we describe a method to examine functional correspondences across species. Without making spatial assumptions, we assessed similarities in sensory-driven functional magnetic resonance imaging responses between monkey (Macaca mulatta) and human brain areas by temporal correlation. Using natural vision data, we revealed regions for which functional processing has shifted to topologically divergent locations during evolution. We conclude that substantial evolution-driven functional reorganizations have occurred, not always consistent with cortical expansion processes. This framework for evaluating changes in functional architecture is crucial to building more accurate evolutionary models.
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3.12Impact points
Effects of mobile phone signals over BOLD response while performing a cognitive task.
Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology. 07/2011; 123(1):129-36.
The aim of this study was to investigate the effects induced by an exposure to a GSM signal (Global System for Mobile Communication) on brain BOLD (blood-oxygen-level dependent) response, as well as its time course while performing a Go-NoGo task. Participants were tested twice, once in presence of ... [more] The aim of this study was to investigate the effects induced by an exposure to a GSM signal (Global System for Mobile Communication) on brain BOLD (blood-oxygen-level dependent) response, as well as its time course while performing a Go-NoGo task. Participants were tested twice, once in presence of a "real" exposure to GSM radiofrequency signal and once under a "sham" exposure (placebo condition). BOLD response of active brain areas and reaction times (RTs) while performing the task were measured both before and after the exposure. RTs to the somatosensory task did not change as a function of exposure (real vs sham) to GSM signal. BOLD results revealed significant activations in inferior parietal lobule, insula, precentral and postcentral gyri associated with Go responses after both ''real'' and ''sham'' exposure, whereas no significant effects were observed in the ROI analysis. The present fMRI study did not detect any brain activity changes by mobile phones. Also RTs in a somatosensory task resulted unaffected. No changes in BOLD response have been observed as a consequence of RF-EMFs exposure.
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5.38Impact points
Differential involvement of somatosensory and interoceptive cortices during the observation of affective touch.
Journal of cognitive neuroscience. 07/2011; 23(7):1808-22.
Previous studies suggested that the observation of other individuals' somatosensory experiences also activates brain circuits processing one's own somatosensory experiences. However, it is unclear whether cortical regions involved with the elementary stages of touch processing are also invol... [more] Previous studies suggested that the observation of other individuals' somatosensory experiences also activates brain circuits processing one's own somatosensory experiences. However, it is unclear whether cortical regions involved with the elementary stages of touch processing are also involved in the automatic coding of the affective consequences of observed touch and to which extent they show overlapping activation for somatosensory experiences of self and others. In order to investigate these issues, in the present fMRI study, healthy participants either experienced touch or watched videos depicting other individuals' inanimate and animate/social touch experiences. Essentially, a distinction can be made between exteroceptive and interoceptive components of touch processing, involved with physical stimulus characteristics and internal feeling states, respectively. Consistent with this distinction, a specific negative modulation was found in the posterior insula by the mere visual perception of other individuals' social or affective cutaneous experiences, compared to neutral inanimate touch. On the other hand, activation in secondary somatosensory and posterior superior temporal regions, strongest for the most intense stimuli, seemed more dependent on the observed physical stimulus characteristics. In contrast to the detected vicarious activation in somatosensory regions, opposite activation patterns for the experience (positive modulation) and observation (negative modulation) of touch suggest that the posterior insula does not reflect a shared representation of self and others' experiences. Embedded in a distributed network of brain regions underpinning a sense of the bodily self, the posterior insula rather appears to differentiate between self and other conditions when affective experiences are implicated.
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2.18Impact points
Passive tactile recognition of geometrical shape in humans: An fMRI study.
Brain research bulletin. 10/2010; 83(5):223-31.
Tactile shape discrimination involves frontal other than somatosensory cortex (Palva et al., 2005 [48]), but it is unclear if this frontal activity is related to exploratory concomitants. In this study, we investigated topographical details of prefrontal, premotor, and parietal areas during passive ... [more] Tactile shape discrimination involves frontal other than somatosensory cortex (Palva et al., 2005 [48]), but it is unclear if this frontal activity is related to exploratory concomitants. In this study, we investigated topographical details of prefrontal, premotor, and parietal areas during passive tactile recognition of 2D geometrical shapes in conditions avoiding exploratory movements. Functional magnetic resonance imaging (fMRI) was performed while the same wooden 2D geometrical shapes were blindly pressed on subjects' passive right palm in three conditions. In the RAW condition, shapes were pressed while subjects were asked to attend to the stimuli but were not trained to recognize them. After a brief training, in the SHAPE condition subjects were asked to covertly recognize shapes. In the RECOGNITION condition, they were asked to overtly recognize shapes, using response buttons with their opposite hand. Results showed that somatosensory cortex including contralateral SII, contralateral SI, and left insula was active in all conditions, confirming its importance in processing tactile shapes. In the RAW vs. SHAPE contrast, bilateral posterior parietal, insular, premotor, prefrontal, and (left) Broca's areas were more active in the latter. In the RECOGNITION, activation of (left) Broca's area correlated with correct responses. These results suggest that, even without exploratory movements, passive recognition of tactile geometrical shapes involves prefrontal and premotor as well as somatosensory regions. In this framework, Broca's area might be involved in a successful selection and/or execution of the correct responses.
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5.74Impact points
Effects of somatosensory stimulation and attention on human somatosensory cortex: an fMRI study.
NeuroImage. 10/2010; 53(1):181-8.
It is well known that primary and non-primary areas of human somatosensory cortex are involved in the processing of adequate deviant/rare stimuli and omission of frequent stimuli. However, the relative weight and interaction of these variables is poorly known. This functional magnetic resonance imag... [more] It is well known that primary and non-primary areas of human somatosensory cortex are involved in the processing of adequate deviant/rare stimuli and omission of frequent stimuli. However, the relative weight and interaction of these variables is poorly known. This functional magnetic resonance imaging (fMRI) study tested the hypothesis that somatosensory stimulus processing and attention especially interact in non-primary somatosensory areas including secondary somatosensory cortex (SII) and insula. To test this hypothesis, responses of somatosensory cortex were mapped during four conditions of an oddball paradigm: DELIVERED COUNT and IGNORE (count or ignore deviant/rare electrical stimuli, respectively); OMITTED COUNT and IGNORE (count or ignore the rare omission of frequent electrical stimuli, respectively). The deviant/rare and frequent electrical stimuli were delivered to median and ulnar nerve, respectively. It was observed that contralateral (left) primary somatosensory responses were not markedly modulated by the mentioned deviant/rare events. Furthermore, contralateral SII and insula responded to all but not OMITTED IGNORE (purely attentive) condition, whereas ipsilateral (right) SII responded to all conditions. Finally, ipsilateral insula responded to the COUNT (attentive) conditions, regardless of the physical presence of the deviant/rare stimuli. The results suggest that in somatosensory modality, bilateral SII and left (contralateral) insula reflect complex integrative processes of stimulus elaboration and attention, whereas right (ipsilateral) insula mainly sub-serves active attention to deviance within a sequence of somatosensory stimuli.
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2.18Impact points
Neural correlates of focused attention and cognitive monitoring in meditation.
Brain research bulletin. 03/2010; 82(1-2):46-56.
Meditation refers to a family of complex emotional and attentional regulatory practices, which can be classified into two main styles - focused attention (FA) and open monitoring (OM) - involving different attentional, cognitive monitoring and awareness processes. In a functional magnetic resonance ... [more] Meditation refers to a family of complex emotional and attentional regulatory practices, which can be classified into two main styles - focused attention (FA) and open monitoring (OM) - involving different attentional, cognitive monitoring and awareness processes. In a functional magnetic resonance study we originally characterized and contrasted FA and OM meditation forms within the same experiment, by an integrated FA-OM design. Theravada Buddhist monks, expert in both FA and OM meditation forms, and lay novices with 10 days of meditation practice, participated in the experiment. Our evidence suggests that expert meditators control cognitive engagement in conscious processing of sensory-related, thought and emotion contents, by massive self-regulation of fronto-parietal and insular areas in the left hemisphere, in a meditation state-dependent fashion. We also found that anterior cingulate and dorsolateral prefrontal cortices play antagonist roles in the executive control of the attention setting in meditation tasks. Our findings resolve the controversy between the hypothesis that meditative states are associated to transient hypofrontality or deactivation of executive brain areas, and evidence about the activation of executive brain areas in meditation. Finally, our study suggests that a functional reorganization of brain activity patterns for focused attention and cognitive monitoring takes place with mental practice, and that meditation-related neuroplasticity is crucially associated to a functional reorganization of activity patterns in prefrontal cortex and in the insula.
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3.29Impact points
Persistent genital arousal disorder associated with functional hyperconnectivity of an epileptic focus.
Neuroscience. 02/2010; 167(1):88-96.
Persistent Genital Arousal Disorder (PGAD) refers to the experience of persistent sensations of genital arousal that are felt to be unprovoked, intrusive and unrelieved by one or several orgasms. It is often mistaken for hypersexuality since PGAD often results in a high frequency of sexual behaviour... [more] Persistent Genital Arousal Disorder (PGAD) refers to the experience of persistent sensations of genital arousal that are felt to be unprovoked, intrusive and unrelieved by one or several orgasms. It is often mistaken for hypersexuality since PGAD often results in a high frequency of sexual behaviour. At present little is known with certainty about the etiology of this condition. We described a woman with typical PGAD symptoms and orgasmic seizures that we found to be related to a specific epileptic focus. We performed a EEG/MEG and fMRI spontaneous activity study during genital arousal symptoms and after the chronic administration of 300 mg/day of topiramate. From MEG data an epileptic focus was localized in the left posterior insular gyrus (LPIG). FMRI data evidenced that sexual excitation symptoms with PGAD could be correlated with an increased functional connectivity (FC) between different brain areas: LPIG (epileptic focus), left middle frontal gyrus, left inferior and superior temporal gyrus and left inferior parietal lobe. The reduction of the FC observed after antiepileptic therapy was more marked in the left than in the right hemisphere in agreement with the lateralization identified by MEG results. Treatment completely abolished PGAD symptoms and functional hyperconnectivity. The functional hyperconnectivity found in the neuronal network including the epileptic focus could suggest a possible central mechanism for PGAD.
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2.14Impact points
A difference exists in somatosensory processing between the anterior and posterior parts of the tongue.
Neuroscience research. 11/2009;
The somatic sensation of the tongue is necessary for daily life, but it is difficult to know the underlying neural mechanisms. In particular, because of the vomiting reflex and several morphological problems, no neuroimaging studies have examined somatosensory processing by stimulating the posterior... [more] The somatic sensation of the tongue is necessary for daily life, but it is difficult to know the underlying neural mechanisms. In particular, because of the vomiting reflex and several morphological problems, no neuroimaging studies have examined somatosensory processing by stimulating the posterior part of the tongue, except for two magnetoencephalographic studies (Sakamoto et al. 2008a, b). This is the first study to clarify the human cortical processing for sensory perception by the posterior part of the tongue with a newly developed device and functional magnetic resonance imaging (fMRI). Stimulation of the left and right postero-lateral parts of the tongue induced significant activity in the primary somatosensory cortex (SI) and Brodmann area 40 in the right hemisphere and the anterior cingulate cortex (ACC). In contrast, antero-lateral stimulation produced activity only in the right SI. The activated region in SI was significantly larger following stimulation of the posterior than anterior part. These results indicate that a clear difference exists in somatosensory processing between stimulation of the antero-lateral and postero-lateral parts of the tongue, and a right hemisphere is dominant for the stimulation of both antero-lateral and postero-lateral areas. The activity in BA40 and ACC may imply that the posterior of the tongue belongs to the visceral system.
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1.93Impact points
Negative BOLD effect on somato-motor inhibitory processing: an fMRI study.
Neuroscience letters. 10/2009; 462(2):101-4.
Inhibiting inappropriate behavior and thoughts in the current context is an essential ability for humans, but the neural mechanisms for response inhibitory processing are a matter of continuous debate. The aim of this event-related functional magnetic resonance imaging (fMRI) study was to evaluate t... [more] Inhibiting inappropriate behavior and thoughts in the current context is an essential ability for humans, but the neural mechanisms for response inhibitory processing are a matter of continuous debate. The aim of this event-related functional magnetic resonance imaging (fMRI) study was to evaluate the negative blood oxygen level dependent (BOLD) effect on inhibitory processing during go/no-go paradigms. Fifteen subjects performed two different types of somatosensory go/no-go paradigm: (1) button press and (2) count. Go and no-go stimuli were presented with an even probability. We observed a common negative activation during Movement No-go and Count No-go trials in the right SFG, corresponding to BA 8. These findings suggest that the right SFG region was responsible for the negative BOLD effect on inhibitory processing, which was independent of the required response mode. We hypothesized several possible explanations for the deactivation of the SFG during no-go trials.
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3.22Impact points
IS THERE "NEURAL EFFICIENCY" DURING THE PROCESSING OF VISUO-SPATIAL INFORMATION IN MALE HUMANS? AN EEG STUDY.
Behavioural brain research. 09/2009;
More intelligent persons (high IQ) typically present a higher cortical activity during tasks requiring the encoding of visuo-spatial information, namely higher alpha (about 10Hz) event-related desynchronization (ERD; Doppelmayr et al. 2005a). The opposite is true ("neural efficiency") duri... [more] More intelligent persons (high IQ) typically present a higher cortical activity during tasks requiring the encoding of visuo-spatial information, namely higher alpha (about 10Hz) event-related desynchronization (ERD; Doppelmayr et al. 2005a). The opposite is true ("neural efficiency") during the retrieval of the encoded information, as revealed by both lower alpha ERD and/or lower theta (about 5Hz) event-related synchronization (ERS; Grabner et al. 2004). To reconcile these contrasting results, here we evaluated the working hypothesis that more intelligent male subjects are characterized by a high cortical activity during the encoding phase. This deep encoding would explain the relatively low cortical activity for the retrieval of the encoded information. To test this hypothesis, electroencephalographic (EEG) data were recorded in 22 healthy young male volunteers during visuo-spatial information processing (encoding) and short-term retrieval of the encoded information. Cortical activity was indexed by theta ERS and alpha ERD. It was found that the higher the subjects' total IQ, the stronger the frontal theta ERS during the encoding task. Furthermore, the higher the subjects' total IQ, the lower the frontal high-frequency alpha ERD (about 10-12Hz) during the retrieval task. This was not true for parietal counterpart of these EEG rhythms. These results reconcile previous contrasting evidence confirming that more intelligent persons do not ever show event-related cortical responses compatible with "neural efficiency" hypothesis. Rather, their cortical activity would depend on flexible and task-adapting features of frontal activation.
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1.93Impact points
Negative BOLD during tongue movement: A functional magnetic resonance imaging study.
Neuroscience letters. 09/2009;
The aim of this functional magnetic resonance imaging (fMRI) study was to evaluate negative blood oxygen level dependent (BOLD) signals during voluntary tongue movement. Deactivated (Negative BOLD) regions included the posterior parietal cortex (PPC), precuneus, and middle temporal gyrus. Activated ... [more] The aim of this functional magnetic resonance imaging (fMRI) study was to evaluate negative blood oxygen level dependent (BOLD) signals during voluntary tongue movement. Deactivated (Negative BOLD) regions included the posterior parietal cortex (PPC), precuneus, and middle temporal gyrus. Activated (Positive BOLD) regions included the primary somatosensory-motor area (SMI), inferior parietal lobule, medial frontal gyrus, superior temporal gyrus, insula, lentiform nucleus, and thalamus. The results were not consistent with previous studies involving unilateral hand and finger movements showing the deactivation of motor-related cortical areas including the ipsilateral MI. The areas of Negative BOLD in the PPC and precuneus might reflect specific neural networks relating to voluntary tongue movement.
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5.74Impact points
Altered brain response without behavioral attention deficits in healthy siblings of schizophrenic patients. An event-related fMRI study.
NeuroImage. 08/2009;
Attention deficits are common in schizophrenics and sometimes reported in their healthy relatives. The aim of this study was to analyse the behavioural performance and the brain activation of healthy siblings of schizophrenic patients during a sustained-attention task. eleven healthy siblings of sch... [more] Attention deficits are common in schizophrenics and sometimes reported in their healthy relatives. The aim of this study was to analyse the behavioural performance and the brain activation of healthy siblings of schizophrenic patients during a sustained-attention task. eleven healthy siblings of schizophrenic patients and eleven matched controls performed a Continuous Performance Test (CPT), during 1.5T fMRI. The stimuli were presented at three difficulty-levels, using different degrees of degradation (0, 25 and 40%). There were no significant differences in CPT performance (mean reaction time and percentage of errors) between the two groups. Performance worsened with increasing degradation in both groups. Differences were found when comparing the BOLD signal change in the medial frontal gyrus/dorsal anterior cingulate, right precentral gyrus, bilateral posterior cingulate and bilateral insula. The most evident between group differences were observed in the left insula/inferior frontal gyrus: siblings showed a larger activation during wrong responses and a reduced activation during correct responses in the degraded runs. In conclusion, healthy siblings of schizophrenic patients showed differences in brain function in several brain regions previously reported in schizophrenic subjects, in the absence of behavioral attention deficits. The differences were greater in the two more difficult levels of attention demand and might be expressions of altered and/or compensatory mechanisms in subjects at increased risk for schizophrenia.
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2.18Impact points
Executive functions with different motor outputs in somatosensory Go/Nogo tasks: An event-related functional MRI study.
Brain research bulletin. 09/2008;
The aim of this event-related functional magnetic resonance imaging (fMRI) study was to investigate and compare executive functions with different motor outputs in somatosensory Go/Nogo tasks: (1) Button press and (2) Count. Go and Nogo stimuli were presented with an even probability. We observed a ... [more] The aim of this event-related functional magnetic resonance imaging (fMRI) study was to investigate and compare executive functions with different motor outputs in somatosensory Go/Nogo tasks: (1) Button press and (2) Count. Go and Nogo stimuli were presented with an even probability. We observed a common network for Movement and Count Go trials in several regions of the brain including the dorsolateral (DLPFC) and ventrolateral prefrontal cortices (VLPFC), supplementary motor area (SMA), posterior parietal cortex (PPC), inferior parietal lobule (IPL), Insula, and superior temporal gyrus (STG). Direct comparison revealed that primary sensorimotor area (SMI), premotor area (PM), and anterior cingulate cortex (ACC) were more activated during Movement than Count Go trials. In contrast, the VLPFC was more activated during Count than Movement Go trials. Our results suggest that there were two neural networks for the supramodal executive function, common and uncommon, depending on the required response mode.
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5.74Impact points
Large-scale brain networks account for sustained and transient activity during target detection.
NeuroImage. 09/2008;
Target detection paradigms have been widely applied in the study of human cognitive functions, particularly those associated with arousal, attention, stimulus processing and memory. In EEG recordings, the detection of task-relevant stimuli elicits the P300 component, a transient response with latenc... [more] Target detection paradigms have been widely applied in the study of human cognitive functions, particularly those associated with arousal, attention, stimulus processing and memory. In EEG recordings, the detection of task-relevant stimuli elicits the P300 component, a transient response with latency around 300 ms. The P300 response has been shown to be affected by the amount of mental effort and learning, as well as habituation. Furthermore, trial-by-trial variability of the P300 component has been associated with inter-stimulus interval, target-to-target interval or target probability; however, understanding the mechanisms underlying this variability is still an open question. In order to investigate whether it could be related to the distinct cortical networks in which coherent intrinsic activity is organized, and to understand the contribution of those networks to target detection processes, we carried out a simultaneous EEG-fMRI study, collecting data from 13 healthy subjects during a visual oddball task. We identified five large-scale networks, that largely overlap with the dorsal attention, the ventral attention, the core, the visual and the sensory-motor networks. Since the P300 component has been consistently associated with target detection, we concentrated on the first two brain networks, the time-course of which showed a modulation with the P300 response as detected in simultaneous EEG recordings. A trial-by-trial EEG-fMRI correlation approach revealed that they are involved in target detection with different functional roles: the ventral attention network, dedicated to revealing salient stimuli, was transiently activated by the occurrence of targets; the dorsal attention network, usually engaged during voluntary orienting, reflected sustained activity, possibly related to search for targets.
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5.74Impact points
Human secondary somatosensory cortex is involved in the processing of somatosensory rare stimuli: an fMRI study.
NeuroImage. 06/2008; 40(4):1765-71.
In the human somatosensory system, the contralateral primary somatosensory cortex (SI) is presumed to process and encode type and intensity of the sensory inputs, whereas the bilateral secondary somatosensory cortex (SII) is believed to perform higher order functions including sensorimotor integrati... [more] In the human somatosensory system, the contralateral primary somatosensory cortex (SI) is presumed to process and encode type and intensity of the sensory inputs, whereas the bilateral secondary somatosensory cortex (SII) is believed to perform higher order functions including sensorimotor integration, integration of information from the two body halves, attention, learning and memory. In this fMRI study we investigated the effect of attention on the activation of SI and SII, as induced by nonpainful and painful rare deviant electric stimuli during somatosensory oddball tasks. The working hypothesis is of stronger effects of attention on SII with respect to SI. Four runs were acquired according to an oddball scheme. Frequent nonpainful electrical stimuli were delivered to the ulnar nerve at motor threshold, whereas rare/deviant stimuli were delivered to median nerve in four conditions (one condition per run): nonpainful, painful, counting nonpainful, and counting painful. Results showed a statistically significant fMRI activation in bilateral SII but not in contralateral SI when the rare/deviant median nerve stimuli were delivered at nonpainful and painful levels as well as at the two levels of attention considered (i.e., associated with counting and non-counting tasks). Furthermore, fMRI activation in SII did not differ across the different levels of stimulus intensity (nonpainful, painful) and attention (non-counting, counting). These results corroborate the notion that SII is the target of independent pathways for the processing and integration of nonpainful and painful somatosensory stimuli salient for further high-order elaborations.
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5.38Impact points
The Sense of Touch: Embodied Simulation in a Visuotactile Mirroring Mechanism for Observed Animate or Inanimate Touch.
Journal of cognitive neuroscience. 04/2008;
Abstract Previous studies have shown a shared neural circuitry in the somatosensory cortices for the experience of one's own body being touched and the sight of intentional touch. Using functional magnetic resonance imaging (fMRI), the present study aimed to elucidate whether the activation of a... [more] Abstract Previous studies have shown a shared neural circuitry in the somatosensory cortices for the experience of one's own body being touched and the sight of intentional touch. Using functional magnetic resonance imaging (fMRI), the present study aimed to elucidate whether the activation of a visuotactile mirroring mechanism during touch observation applies to the sight of any touch, that is, whether it is independent of the intentionality of observed touching agent. During fMRI scanning, healthy participants viewed video clips depicting a touch that was intentional or accidental, and occurring between animate or inanimate objects. Analyses showed equal overlapping activation for all the touch observation conditions and the experience of one's own body being touched in the bilateral secondary somatosensory cortex (SII), left inferior parietal lobule (IPL)/supramarginal gyrus, bilateral temporal-occipital junction, and left precentral gyrus. A significant difference between the sight of an intentional touch, compared to an accidental touch, was found in the left primary somatosensory cortex (SI/Brodmann's area [BA] 2). Interestingly, activation in SI/BA 2 significantly correlated with the degree of intentionality of the observed touch stimuli as rated by participants. Our findings show that activation of a visuotactile mirroring mechanism for touch observation might underpin an abstract notion of touch, whereas activation in SI might reflect a human tendency to "resonate" more with a present or assumed intentional touching agent.
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5.74Impact points
Somato-motor inhibitory processing in humans: an event-related functional MRI study.
NeuroImage. 03/2008; 39(4):1858-66.
Inhibiting inappropriate behavior and thoughts is an essential ability for humans, but the regions responsible for inhibitory processing are a matter of continuous debate. This is the first study of somatosensory go/nogo tasks using event-related functional magnetic resonance imaging (fMRI). Fifteen... [more] Inhibiting inappropriate behavior and thoughts is an essential ability for humans, but the regions responsible for inhibitory processing are a matter of continuous debate. This is the first study of somatosensory go/nogo tasks using event-related functional magnetic resonance imaging (fMRI). Fifteen subjects preformed two different types of go/nogo task, i.e. (1) Movement and (2) Count, to compare with previous studies using visual go/nogo tasks, and confirm whether the inhibitory processing is dependent on sensory modalities. Go and nogo stimuli were presented with an even probability. Our data indicated that the response inhibition network involved the dorsolateral (DLPFC) and ventrolateral (VLPFC) prefrontal cortices, pre-supplementary motor area (pre-SMA), anterior cingulate cortex (ACC), inferior parietal lobule (IPL), insula, and temporoparietal junction (TPJ), which were consistent with previous results obtained using visual go/nogo tasks. These activities existed in both Movement and Count Nogo trials. Therefore, our results suggest that the network for inhibitory processing is not dependent on sensory modalities but reflects common neural activities. In addition, there were differences of activation intensity between Movement and Count Nogo trials in the prefrontal cortex, temporal lobe, and ACC. Thus, inhibitory processing would involve two neural networks, common and uncommon regions, depending on the required response mode.
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6.98Impact points
Human neural systems for conceptual knowledge of proper object use: a functional magnetic resonance imaging study.
Cerebral cortex (New York, N.Y. : 1991). 12/2007; 17(11):2744-51.
Ideational apraxia is characterized by impaired knowledge of action concepts and proper object usage. The present functional magnetic resonance imaging study aimed at investigating the neural system underlying conceptual knowledge for proper object use in healthy subjects, when the effects of visuos... [more] Ideational apraxia is characterized by impaired knowledge of action concepts and proper object usage. The present functional magnetic resonance imaging study aimed at investigating the neural system underlying conceptual knowledge for proper object use in healthy subjects, when the effects of visuospatial properties and perceptual modality were taken into account. Subjects performed semantic decision tasks requiring retrieval of knowledge about either object functional purposes (functional task) or visuospatial object properties (visuospatial task) and perceptual control tasks. The semantic tasks were performed with pairs of either written object names or object drawings. Activation for the functional task in common for words and pictures, compared with the visuospatial and control tasks, was found in left parietal-temporal-occipital (PTO) junction, inferior frontal, anterior dorsal premotor, and presupplementary motor areas. Ventral inferior frontal cortex activation correlated negatively with reaction time in the functional condition. No specific activation characterized the visuospatial task compared with the functional task. The conceptual tasks, compared with the control tasks, demonstrated overlapping activation in left PTO junction, prefrontal, dorsal premotor, cuneus, and inferior temporal areas. These results outline the neural processes underlying conceptual knowledge for proper object use. The left ventral inferior frontal gyrus might facilitate behavioral decisions regarding functional/pragmatical object properties.
Following (26)
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Gianna Sepede
Università degli Studi G. d'Annunzio Chieti e Pescara -
Pasqua Mercuri
Università degli Studi G. d'Annunzio Chieti e Pescara -
Nicoletta Savini
Università degli Studi G. d'Annunzio Chieti e Pescara -
Raffaele Sinibaldi
Università degli Studi G. d'Annunzio Chieti e Pescara -
Michael Doppelmayr
Universität Salzburg
