IMT Institutional Repository: No conditions. Results ordered -Date Deposited. 2024-03-29T05:20:15ZEPrintshttp://eprints.imtlucca.it/images/logowhite.pnghttp://eprints.imtlucca.it/2016-09-12T11:53:14Z2016-09-13T06:34:44Zhttp://eprints.imtlucca.it/id/eprint/3534This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/35342016-09-12T11:53:14ZEffects of visual experience on the human MT+ functional connectivity networks: an fMRI study of motion perception in sighted and congenitally blind individualsHuman middle temporal complex (hMT+) responds also to the perception of non-visual motion in both sighted and early blind individuals, indicating a supramodal organization. Visual experience, however, leads to a segregation of hMT+ into a more anterior subregion, involved in the supramodal representation of motion, and a posterior subregion that processes visual motion only. In contrast, in congenitally blind subjects tactile motion activates the full extent of hMT+. Here, we used fMRI to investigate brain areas functionally connected with the two hMT+ subregions (seeds) during visual and tactile motion in sighted and blind individuals. A common functional connectivity network for motion processing, including bilateral ventral and dorsal extrastriate, inferior frontal, middle and inferior temporal areas, correlated with the two hMT+ seeds both in sighted and blind individuals during either visual or tactile motion, independently from the sensory modality through which the information was acquired. Moreover, ventral premotor, somatosensory, and posterior parietal areas correlated only with the anterior but not with the posterior portion of hMT+ in sighted subjects, and with both hMT+ seeds in blind subjects. Furthermore, a correlation between middle temporal and occipital areas with primary somatosensory seeds was demonstrated across conditions in both sighted and blind individuals, suggesting a cortico-cortical pathway that conveys non-visual information from somatosensory cortex, through posterior parietal regions, to ventral extrastriate cortex. These findings expand our knowledge about the development of the functional organization within hMT+ by showing that distinct patterns of brain functional correlations originate from the anterior and posterior hMT+ subregions as a result of visual experience.Pietro Pietrinipietro.pietrini@imtlucca.itJames V. HaxbyNicola VanelloClaudio GentiliEmiliano Ricciardiemiliano.ricciardi@imtlucca.itLorenzo Sani2016-04-20T09:56:31Z2016-04-20T09:56:31Zhttp://eprints.imtlucca.it/id/eprint/3467This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/34672016-04-20T09:56:31ZPatterns of cerebral metabolic interactions are altered in the early stages of Alzheimer’s disease: a longitudinal PET studyPietro Pietrinipietro.pietrini@imtlucca.itNina P. AzariCheryl L. GradyJudith A. SalernoA. Gonzales-AvilesL. L. HestonKaren D. PettigrewBarry HorwitzJames V. HaxbyMark B. Schapiro2016-04-20T09:46:04Z2016-04-20T09:46:04Zhttp://eprints.imtlucca.it/id/eprint/3466This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/34662016-04-20T09:46:04ZPositron Emission Tomography (PET) as a tool to investigate cerebral glucose metabolism in neurologic and psychiatric disorders. Studies in dementia of the Alzheimer type and obsessive-compulsive disorderPietro Pietrinipietro.pietrini@imtlucca.itMario GuazzelliPietro SarteschiCheryl L. GradyJames V. HaxbySusan E. SwedoStanley I. RapoportMark B. Schapiro2016-04-20T09:39:38Z2016-04-20T09:39:38Zhttp://eprints.imtlucca.it/id/eprint/3465This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/34652016-04-20T09:39:38ZA statistical procedure applied to positron emission tomographic (PET) data for the early detection of Alzheimer’s disease (AD)Nina P. AzariKaren D. PettigrewMark B. SchapiroJames V. HaxbyCheryl L. GradyPietro Pietrinipietro.pietrini@imtlucca.itJudith A. SalernoL. L. HestonStanley I. RapoportBarry Horwitz2016-04-12T09:15:51Z2016-04-12T09:15:51Zhttp://eprints.imtlucca.it/id/eprint/3419This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/34192016-04-12T09:15:51ZLow glucose metabolism during brain stimulation in older Down's syndrome subjects at risk for Alzheimer's disease prior to dementiaOBJECTIVE: Down's syndrome is characterized by the genetically programmed accumulation of substantial Alzheimer's disease neuropathology after age 40 and the development of early dementia years later, providing a unique human model to investigate the preclinical phases of Alzheimer's disease. Older nondemented adults with Down's syndrome show normal rates of regional cerebral glucose metabolism at rest before the onset of dementia, indicating that their neurons maintain function at rest. The authors hypothesized that an audiovisual stimulation paradigm, acting as a stress test, would reveal abnormalities in cerebral glucose metabolism before dementia in the neocortical parietal and temporal areas most vulnerable to Alzheimer's disease. METHOD: Regional cerebral glucose metabolism was assessed by means of positron emission tomography (PET) with [18F]fluorodeoxyglucose in eight younger (mean age = 35 years, SD = 2) and eight older (mean age = 50, SD = 7) healthy, nondemented adults with trisomy 21 Down's syndrome. PET scans were performed at rest and during audiovisual stimulation in the same scanning session. Levels of general intellectual functioning and compliance were similar in the two groups. RESULTS: At rest the two groups showed no difference in glucose metabolism in any cerebral region. In contrast, during audiovisual stimulation the older subjects with Down's syndrome had significantly lower glucose metabolic rates in the parietal and temporal cortical areas. CONCLUSIONS: Abnormalities in cerebral metabolism during stimulation appeared in the first cortical regions typically affected in Alzheimer's disease. These results indicate that a stress test paradigm can detect metabolic abnormalities in the preclinical stages of Alzheimer's disease despite normal cerebral metabolism at rest.Pietro Pietrinipietro.pietrini@imtlucca.itAlessio DaniMaura L. FureyGene E. AlexanderUlderico FreoCheryl L. GradyMarc J. MentisDavid MangotElliot W. SimonBarry HorwitzJames V. HaxbyMark B. Schapiro2016-04-12T09:10:06Z2016-04-12T09:10:06Zhttp://eprints.imtlucca.it/id/eprint/3417This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/34172016-04-12T09:10:06ZCholinergic stimulation alters performance and task-specific regional cerebral blood flow during working memoryModulation of the cholinergic neurotransmitter system results in changes in memory performance, including working memory (WM), in animals and in patients with Alzheimer disease. To identify associated changes in the functional brain response, we studied performance measures and regional cerebral blood flow (rCBF) using positron emission tomography (PET) in healthy subjects during performance of a WM task. Eight control subjects received an infusion of saline throughout the study and 13 experimental subjects received a saline infusion for the first 2 scans followed by a continuous infusion of physostigmine, an acetylcholinesterase inhibitor, for the subsequent 8 scans. rCBF was measured using H215O and PET in a sequence of 10 PET scans that alternated between rest and task scans. During task scans, subjects performed the WM task for faces. Physostigmine both improved WM efficiency, as indicated by faster reaction times, and reduced WM task-related activity in anterior and posterior regions of right midfrontal gyrus, a region shown previously to be associated with WM. Furthermore, the magnitudes of physostigmine-induced change in reaction time and right midfrontal rCBF correlated. These results suggest that enhancement of cholinergic function can improve processing efficiency and thus reduce the effort required to perform a WM task, and that activation of right prefrontal cortex is associated with task effort.Maura L. FureyPietro Pietrinipietro.pietrini@imtlucca.itJames V. HaxbyGene E. AlexanderH.C. LeeJ. Van MeterCheryl L. GradyUmesha ShettyStanley I. RapoportMark B. SchapiroUlderico Freo2016-04-12T08:55:14Z2016-04-13T10:06:03Zhttp://eprints.imtlucca.it/id/eprint/3413This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/34132016-04-12T08:55:14ZA {PET} study of turner's syndrome: Effects of sex steroids and the X chromosome on brainWomen with Turner's syndrome (TS) allow us to study the neurobiological associates of cognitive and behavioral abnormalities because they lack one/part of one X chromosome, and endogenous estrogen. We studied 13 healthy controls (mean age ± SD, 28 ± 6 years) and 16 {TS} subjects (mean age ± SD, 26 ± 6 years). We measured cognitive abilities using neuropsychological tests, and cerebral metabolic rates for glucose with positron emission tomography. Compared to controls, {TS} subjects had significant absolute hypermetabolism in most brain areas; however, normalized metabolism was significantly lower in {TS} subjects than controls in the insula and association neocortices bilaterally, and there were significant differences in functional metabolic associations of brain region pairs originating in occipital cortex bilaterally, and within the right hemisphere. There were significant correlations between right-left cognitive and metabolic asymmetries in the {TS} group. Also, within {TS} a preliminary analysis demonstrated “X chromosome dosage” effects in language ability and left temporal metabolism, asymmetry of right-left test scores, and parietal metabolism. We hypothesize that within TS: i) generalized brain hypermetabolism reflects global abnormalities in neuron packing; ii) neuronal abnormalities occur in association neocortex that differ in nature or extent from whole brain and are associated with significant differences in normalized metabolism; iii) cognitive deficits are related to brain metabolic abnormalities; and iv) social-behavioral problems may be related to abnormalities of brain metabolism. Moreover, in human brain the X chromosome involved in development of the association neocortices.Declan G. MurphyMark J. MentisPietro Pietrinipietro.pietrini@imtlucca.itCheryl L. GradyEileen DalyJames V. HaxbyMaria De La GranjaGregory AllenKimberley LargayBeverley J. WhiteClaire M. PowellBarry HorwitzStanley I. RapoportMark B. Schapiro2016-04-12T08:32:42Z2016-04-12T08:32:42Zhttp://eprints.imtlucca.it/id/eprint/3408This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/34082016-04-12T08:32:42ZCholinergic enhancement and increased selectivity of perceptual processing during working memoryUsing functional magnetic resonance imaging, we investigated the mechanism by which cholinergic enhancement improves working memory. We studied the effect of the cholinesterase inhibitor physostigmine on subcomponents of this complex function. Cholinergic enhancement increased the selectivity of neural responses in extrastriate cortices during visual working memory, particularly during encoding. It also increased the participation of ventral extrastriate cortex during memory maintenance and decreased the participation of anterior prefrontal cortex. These results indicate that cholinergic enhancement improves memory performance by augmenting the selectivity of perceptual processing during encoding, thereby simplifying processing demands during memory maintenance and reducing the need for prefrontal participation.Maura L. FureyPietro Pietrinipietro.pietrini@imtlucca.itJames V. Haxby2016-04-07T09:46:32Z2016-04-07T09:46:32Zhttp://eprints.imtlucca.it/id/eprint/3395This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33952016-04-07T09:46:32ZDistributed and overlapping representations of faces and objects in ventral temporal cortexThe functional architecture of the object vision pathway in the human brain was investigated using functional magnetic resonance imaging to measure patterns of response in ventral temporal cortex while subjects viewed faces, cats, five categories of man-made objects, and nonsense pictures. A distinct pattern of response was found for each stimulus category. The distinctiveness of the response to a given category was not due simply to the regions that responded maximally to that category, because the category being viewed also could be identified on the basis of the pattern of response when those regions were excluded from the analysis. Patterns of response that discriminated among all categories were found even within cortical regions that responded maximally to only one category. These results indicate that the representations of faces and objects in ventral temporal cortex are widely distributed and overlapping.James V. HaxbyMaria Ida GobbiniMaura L. FureyAlumit IshaiJennifer L. SchoutenPietro Pietrinipietro.pietrini@imtlucca.it2016-04-07T09:19:29Z2016-04-07T09:19:29Zhttp://eprints.imtlucca.it/id/eprint/3389This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33892016-04-07T09:19:29ZAdvance image processing in clinical and research applicationsDavide CaramellaEmanuele NeriM. LombardiLuigi LandiniVincenzo PositanoS. La MannaA. StaritaPietro Pietrinipietro.pietrini@imtlucca.itMario GuazzelliJames V. HaxbyCarlo Bartolozzi2016-04-07T08:29:37Z2016-04-07T08:29:37Zhttp://eprints.imtlucca.it/id/eprint/3387This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33872016-04-07T08:29:37ZDistinct, overlapping representations of faces and multiple categories of objects in ventral temporal cortexJames V. HaxbyMaria Ida GobbiniMaura L. FureyAlumit IshaiPietro Pietrinipietro.pietrini@imtlucca.it2016-04-06T12:55:25Z2016-09-13T10:19:13Zhttp://eprints.imtlucca.it/id/eprint/3380This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33802016-04-06T12:55:25ZNeural Activity in Ventral Extrastriate Cortex during Tactile
Discrimination of Faces and Other Objects in Congenitally Blind and
Sighted SubjectsPietro Pietrinipietro.pietrini@imtlucca.itMaura L. FureyEmiliano Ricciardiemiliano.ricciardi@imtlucca.itMaria Ida GobbiniW.-H. Carolyn WuLeonardo CohenMario GuazzelliJames V. Haxby2016-04-06T12:13:52Z2016-09-13T10:18:31Zhttp://eprints.imtlucca.it/id/eprint/3377This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33772016-04-06T12:13:52ZSeeing with one's hands: Supramodal cortical organization of perception in the human brain revealed by fMRIPietro Pietrinipietro.pietrini@imtlucca.itMaura L. FureyEmiliano Ricciardiemiliano.ricciardi@imtlucca.itMaria Ida GobbiniMario GuazzelliJames V. Haxby2016-04-05T10:24:52Z2016-09-13T10:15:35Zhttp://eprints.imtlucca.it/id/eprint/3374This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33742016-04-05T10:24:52ZBeyond sensory images: Object-based representation in the human ventral pathwayWe investigated whether the topographically organized, category-related patterns of neural response in the ventral visual pathway are a representation of sensory images or a more abstract representation of object form that is not dependent on sensory modality. We used functional MRI to measure patterns of response evoked during visual and tactile recognition of faces and manmade objects in sighted subjects and during tactile recognition in blind subjects. Results showed that visual and tactile recognition evoked category-related patterns of response in a ventral extrastriate visual area in the inferior temporal gyrus that were correlated across modality for manmade objects. Blind subjects also demonstrated category-related patterns of response in this “visual” area, and in more ventral cortical regions in the fusiform gyrus, indicating that these patterns are not due to visual imagery and, furthermore, that visual experience is not necessary for category-related representations to develop in these cortices. These results demonstrate that the representation of objects in the ventral visual pathway is not simply a representation of visual images but, rather, is a representation of more abstract features of object form.Pietro Pietrinipietro.pietrini@imtlucca.itMaura L. FureyEmiliano Ricciardiemiliano.ricciardi@imtlucca.itMaria Ida GobbiniW.-H. Carolyn WuLeonardo CohenMario GuazzelliJames V. Haxby2016-04-05T09:57:58Z2016-09-13T10:17:50Zhttp://eprints.imtlucca.it/id/eprint/3372This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33722016-04-05T09:57:58ZPerception of optic and tactile flow both activate V5/MT cortical complex in the human brainV5/MT complex responds selectively to perception of optic flow (Morrone et al., Nature Neurosci , 2001). Since similarities exist between visual and tactile perception, we hypothesized that tactile flow might also rely on V5/MT response. We and others have shown recently that visual extrastriate cortical areas respond both during visual and tactile recognition of objects, indicating that these regions are organized in a supramodal fashion. In this study, we measured neural response evoked during visual and tactile perception of coherently moving dot patterns to test the hypothesis that V5/MT may be supramodally organized and may respond also to tactile stimulation.Nicola VanelloEmiliano Ricciardiemiliano.ricciardi@imtlucca.itDavide DenteNicola SgambelluriEnzo Pasquale ScilingoClaudio GentiliLorenzo SaniVincenzo PositanoMaria Filomena SantarelliMario GuazzelliJames V. HaxbyLuigi LandiniAntonio BicchiPietro Pietrinipietro.pietrini@imtlucca.it2016-04-05T08:38:11Z2016-09-13T10:16:36Zhttp://eprints.imtlucca.it/id/eprint/3367This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33672016-04-05T08:38:11ZTactile processing of different object categories involves extrastriate visual cortical areas in the human brainFunctional magnetic resonance imaging (fMRI) studies demonstrated
that tactile discrimination evokes patterns of neural response in the extrastriate
ventral temporal cortical areas similar to those induced by the visual percept of
the same category of objects. These findings strongly indicate that object
representation in the ventral visual pathway is not simply a representation of
visual images but quite a representation of more abstract features of object
form.Emiliano Ricciardiemiliano.ricciardi@imtlucca.itMaura L. FureyMaria Ida GobbiniMario GuazzelliJames V. HaxbyPietro Pietrinipietro.pietrini@imtlucca.it2016-04-04T10:18:59Z2016-09-13T10:17:16Zhttp://eprints.imtlucca.it/id/eprint/3357This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33572016-04-04T10:18:59ZPerception of visual and tactile flow activates common cortical areas in the human brainWe report results of a pilot study using functional magnetic resonance
imaging aimed at determining the neural correlates of tactile flow. We
hypothesized that brain response to tactile flow would involve the same cortical
areas (V5/MT) that respond to optic flow. Our results showed that V5/MT cortex
indeed is activated by tactile flow perception. These findings are consistent
with a supramodal organization of brain regions involved in optic and tactile
flow processingEmiliano Ricciardiemiliano.ricciardi@imtlucca.itNicola VanelloDavide DenteNicola SgambelluriEnzo Pasquale ScilingoClaudio GentiliLorenzo SaniVincenzo PositanoMaria Filomena SantarelliMario GuazzelliJames V. HaxbyLuigi LandiniAntonio BicchiPietro Pietrinipietro.pietrini@imtlucca.it2016-04-04T09:49:45Z2016-09-13T10:16:22Zhttp://eprints.imtlucca.it/id/eprint/3354This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33542016-04-04T09:49:45ZSupramodal, topographic and category-related organization in the ventral visual pathwayEmiliano Ricciardiemiliano.ricciardi@imtlucca.itMaura L. FureyMaria Ida GobbiniMario GuazzelliJames V. HaxbyPietro Pietrinipietro.pietrini@imtlucca.it2016-03-24T09:26:18Z2016-04-05T12:33:15Zhttp://eprints.imtlucca.it/id/eprint/3339This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33392016-03-24T09:26:18ZThe functional organization of human extrastriate cortex: a PET-rCBF study of selective attention to faces and locationsThe functional dissociation of human extrastriate cortical processing streams for the perception of face identity and location was investigated in healthy men by measuring visual task-related changes in regional cerebral blood flow (rCBF) with positron emission tomography (PET) and H2(15)O. Separate scans were obtained while subjects performed face matching, location matching, or sensorimotor control tasks. The matching tasks used identical stimuli for some scans and stimuli of equivalent visual complexity for others. Face matching was associated with selective rCBF increases in the fusiform gyrus in occipital and occipitotemporal cortex bilaterally and in a right prefrontal area in the inferior frontal gyrus. Location matching was associated with selective rCBF increases in dorsal occipital, superior parietal, and intraparietal sulcus cortex bilaterally and in dorsal right premotor cortex. Decreases in rCBF, relative to the sensorimotor control task, were observed for both matching tasks in auditory, auditory association, somatosensory, and midcingulate cortex. These results suggest that, within a sensory modality, selective attention is associated with increased activity in those cortical areas that process the attended information but is not associated with decreased activity in areas that process unattended visual information. Selective attention to one sensory modality, on the other hand, is associated with decreased activity in cortical areas dedicated to processing input from other sensory modalities. Direct comparison of our results with those from other PET-rCBF studies of extrastriate cortex demonstrates agreement in the localization of cortical areas mediating face and location perception and dissociations between these areas and those mediating the perception of color and motion.James V. HaxbyBarry HorwitzLeslie G. UngerleiderJose Ma MaisogPietro Pietrinipietro.pietrini@imtlucca.itCheryl L. Grady2016-03-24T09:21:41Z2016-04-05T12:32:37Zhttp://eprints.imtlucca.it/id/eprint/3338This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33382016-03-24T09:21:41ZAge-related changes in cortical blood flow activation during visual processing of faces and locationWe examined age-related changes in object and spatial visual processing in two separate experiments. Regional cerebral blood flow (rCBF) was measured in young and old subjects with positron emission tomography and H2(15)O during tests of face matching, location matching, and a control task. The task demands in the two experiments were identical, but the stimuli in Experiment II were constructed to equalize stimulus complexity across all three tasks. The old subjects performed more slowly than the young subjects in both experiments, and showed significantly slower reaction times during location matching compared to face matching in Experiment II. Both young and old subjects showed occipitotemporal rCBF activation during face matching and occipitoparietal activation during location matching when these conditions were compared to the control task. However, in both experiments and in both tasks, young subjects showed greater activation of prestriate cortex (Brodmann's area 18), and old subjects had larger rCBF increases in occipitotemporal cortex (area 37). Areas in prefrontal cortex, as well as in inferior and medial parietal cortex, were more activated in the old subjects during location matching in both experiments. These results demonstrate that reliable age-related changes during visual processing can be found in rCBF patterns, suggesting more efficient use of occipital visual areas by younger subjects and more reliance by older subjects on one or more cortical networks, particularly for spatial vision, perhaps to compensate for reduced processing efficiency of occipital cortex. Both the differentially increased reaction times and the more widespread prefrontal activation in the old subjects during location matching suggest that spatial vision may be affected to a greater degree by aging than is object vision.Cheryl L. GradyJose Ma MaisogBarry HorwitzLeslie G. UngerleiderMarc J. MentisJudith A. SalernoPietro Pietrinipietro.pietrini@imtlucca.itElizabeth WagnerJames V. Haxby2016-03-23T13:56:32Z2016-04-05T12:29:14Zhttp://eprints.imtlucca.it/id/eprint/3332This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33322016-03-23T13:56:32ZEarly Detection of Alzheimer's Disease: A Statistical Approach Using Positron Emission Tomographic DataCorrelational analysis of regional cerebral glucose metabolism (rCMRglc) obtained by high-resolution positron emission tomography (PET) has demonstrated reduced neocortical rCMRglc interactions in mildly/moderately demented patients with probable Alzheimer's disease (AD). Thus, identification of individual differences in patterns of rCMRglc interactions may be important for the early detection of AD, particularly among individuals at greater risk for developing AD (e.g., those with a family history of AD). Recently, a statistical procedure, using multiple regression and discriminant analysis, was developed to assess individual differences in patterns of rCMRglc interdependencies. We applied this new statistical procedure to resting rCMRglc PET data from mildly/moderately demented patients with probable AD and age/sex-matched controls. The aims of the study were to identify a discriminant function that would (a) distinguish patients from controls and (b) identify an AD pattern in an individual at risk for AD with isolated memory impairment whose initial PET scan showed minor abnormalities, but whose second scan showed parietal hypometabolism, coincident with further cognitive decline. Two discriminant functions, reflecting interactions involving regions most involved in reduced correlations in probable AD, correctly classified 87 of the patients and controls, and successfully identified the first scan of the at-risk individual as AD (probability >0.70). The results suggest that this statistical approach may be useful for the early detection of AD.Nina P. AzariKaren D. PettigrewMark B. SchapiroJames V. HaxbyCheryl L. GradyPietro Pietrinipietro.pietrini@imtlucca.itJudith A. SalernoL. L. HestonStanley I. RapoportBarry Horwitz2016-03-23T13:49:49Z2016-04-06T08:32:35Zhttp://eprints.imtlucca.it/id/eprint/3329This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33292016-03-23T13:49:49ZStriatal Glucose Metabolism and Pattern of Cerebral Regional Interactions in Choreic DisordersWith positron emission tomography (PET), cerebral glucose metabolism was studied in 5 patients with familial inverted chorea, a progressive choreiform disease with no dementia, and in age- and sex-matched control subjects. Computed tomography scans excluded cortical or striatal atrophy. PET scans showed no group differences in striatal glucose metabolism. However, when a discriminant analysis method was applied to the PET metabolic data, a discriminant function, reflecting functional interactions involving the striatum, successfully distinguished the patients from the control subjects. These results indicate striatal involvement in the pathophysiology of familial inverted chorea, and emphasize the importance of alternative methods of analyzing regional PET data.Pietro Pietrinipietro.pietrini@imtlucca.itNina P. AzariKaren D. PettigrewBarry HorwitzW. KozachukAnand KumarJudith A. SalernoCheryl L. GradyJames V. HaxbyN. AroninP. MarshallMark B. Schapiro2016-03-23T13:47:40Z2016-04-05T12:33:57Zhttp://eprints.imtlucca.it/id/eprint/3328This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33282016-03-23T13:47:40ZPattern of cerebral metabolic interactions in a subject with isolated amnesia at risk for Alzheimer's disease: A longitudinal evaluationA pattern of reduced cerebral metabolic rate for glucose (rCMRglc) has been shown by positron emission tomography (PET) in patients with dementia of the Alzheimer type. To verify if a similar rCMRglc pattern is present in subjects 'at risk' for Alzheimer's disease (AD), we used high-resolution PET to longitudinally study a subject with isolated memory impairment and a family history for autosomal dominant AD. Initial rCMRglc data did not reveal any consistent abnormality as compared to a group of sex- and age-matched healthy controls. However, 1 year later, a follow-up evaluation did reveal reduced parietal rCMRglc values coinciding with a worsening of cognitive impairment, which suggested that standard analyses of resting rCMRglc data may not be useful in the early diagnosis of AD. In contrast, when a previously determined discriminant function for distinguishing controls from AD patients was applied, the subject was correctly identified as an AD patient on both PET scans.Pietro Pietrinipietro.pietrini@imtlucca.itNina P. AzariCheryl L. GradyJudith A. SalernoA. Gonzales-AvilesL. L. HestonKaren D. PettigrewBarry HorwitzJames V. HaxbyMark B. Schapiro2016-03-23T13:44:21Z2016-04-06T08:32:15Zhttp://eprints.imtlucca.it/id/eprint/3327This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33272016-03-23T13:44:21ZReductions in parietal and temporal cerebral metabolic rates for glucose are not specific for Alzheimer's diseaseReduction in the regional cerebral metabolic rate for glucose (rCMRglc) in the parietal and temporal regions has been shown in Alzheimer's disease (AD). The specificity of these findings for this disease state is uncertain. We repeatedly measured rCMRglc with positron emission tomography and 18F2-fluoro-2-deoxy-D-glucose in the resting state in a 68 year old man with slowly progressive dementia who, during life, was initially diagnosed as having dementia of the Alzheimer type, then Parkinson disease with dementia, but was found to have only Parkinson's disease at necropsy. Metabolic ratios (rCMRglc/mean grey CMRglc) were significantly (p <0 05) reduced in parietal and temporal regions, as well as in the prefrontal and premotor areas. This pattern was similar in regional distribution and magnitude of the defect to that seen in patients with probable AD. These results suggest that reductions of glucose metabolism in association neocortex in AD are not specific to the disease process, but may be related to the dementia state.Mark B. SchapiroPietro Pietrinipietro.pietrini@imtlucca.itCheryl L. GradyM.J. BallCharles De CarliAnand KumarJeffrey A. KayeJames V. Haxby2016-03-23T10:54:48Z2016-09-13T10:14:50Zhttp://eprints.imtlucca.it/id/eprint/3309This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33092016-03-23T10:54:48ZSupramodal organization in the "visual" cortical pathways as assessed by functional magnetic resonance in humansEmiliano Ricciardiemiliano.ricciardi@imtlucca.itNicola VanelloDaniela BoninoClaudio GentiliLorenzo SaniSabrina DantiNicola SgambelluriJames V. HaxbyLuigi LandiniTomaso VecchiMario GuazzelliAntonio BicchiPietro Pietrinipietro.pietrini@imtlucca.it2016-03-23T10:46:51Z2016-09-13T10:13:48Zhttp://eprints.imtlucca.it/id/eprint/3308This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33082016-03-23T10:46:51ZFacial expression representation in the superior temporal sulcus and in fusiform gyrus: an fMRI studyMaria Ida GobbiniClaudio GentiliPietro Pietrinipietro.pietrini@imtlucca.itEmiliano Ricciardiemiliano.ricciardi@imtlucca.itNicola VanelloMario GuazzelliJames V. Haxby2016-03-23T10:34:11Z2016-09-13T10:14:39Zhttp://eprints.imtlucca.it/id/eprint/3306This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/33062016-03-23T10:34:11ZSupramodal response of human MT+ complex to visual and tactile perception of flow as demonstrated by fMRI studies in sighted and congenitally blind individualsEmiliano Ricciardiemiliano.ricciardi@imtlucca.itLorenzo SaniClaudio GentiliNicola VanelloJames V. HaxbyLuigi LandiniAntonio BicchiPietro Pietrinipietro.pietrini@imtlucca.it2016-02-29T10:11:17Z2016-09-13T10:09:03Zhttp://eprints.imtlucca.it/id/eprint/3162This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/31622016-02-29T10:11:17ZThe Effect of Visual Experience on the Development of Functional Architecture in hMT+We investigated whether the visual hMT+ cortex plays a role in supramodal representation of sensory flow, not mediated by visual mental imagery. We used functional magnetic resonance imaging to measure neural activity in sighted and congenitally blind individuals during passive perception of optic and tactile flows. Visual motion–responsive cortex, including hMT+, was identified in the lateral occipital and inferior temporal cortices of the sighted subjects by response to optic flow. Tactile flow perception in sighted subjects activated the more anterior part of these cortical regions but deactivated the more posterior part. By contrast, perception of tactile flow in blind subjects activated the full extent, including the more posterior part. These results demonstrate that activation of hMT+ and surrounding cortex by tactile flow is not mediated by visual mental imagery and that the functional organization of hMT+ can develop to subserve tactile flow perception in the absence of any visual experience. Moreover, visual experience leads to a segregation of the motion-responsive occipitotemporal cortex into an anterior subregion involved in the representation of both optic and tactile flows and a posterior subregion that processes optic flow only.Emiliano Ricciardiemiliano.ricciardi@imtlucca.itNicola VanelloLorenzo SaniClaudio GentiliEnzo Pasquale ScilingoLuigi LandiniMario GuazzelliAntonio BicchiJames V. HaxbyPietro Pietrinipietro.pietrini@imtlucca.it2016-02-29T09:42:53Z2016-02-29T09:42:53Zhttp://eprints.imtlucca.it/id/eprint/3157This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/31572016-02-29T09:42:53ZSelective Effects of Cholinergic Modulation on Task Performance during Selective AttentionThe cholinergic neurotransmitter system is critically linked to cognitive functions including attention. The current studies were designed to evaluate the effect of a cholinergic agonist and an antagonist on performance during a selective visual attention task where the inherent salience of attended/unattended stimuli was modulated. Two randomized, placebo-controlled, crossover studies were performed, one (n=9) with the anticholinesterase physostigmine (1.0 mg/h), and the other (n=30) with the anticholinergic scopolamine (0.4 mc/kg). During the task, two double-exposure pictures of faces and houses were presented side by side. Subjects were cued to attend to either the face or the house component of the stimuli, and were instructed to perform a matching task with the two exemplars from the attended category. The cue changed every 4–7 trials to instruct subjects to shift attention from one stimulus component to the other. During placebo in both studies, reaction time (RT) associated with the first trial following a cued shift in attention was longer than RT associated with later trials (p<0.05); RT also was significantly longer when attending to houses than to faces (p<0.05). Physostigmine decreased RT relative to placebo preferentially during trials greater than one (p<0.05), with no change during trial one; and decreased RT preferentially during the attention to houses condition (p<0.05) vs attention to faces. Scopolamine increased RT relative to placebo selectively during trials greater than one (p<0.05), and preferentially increased RT during the attention to faces condition (p<0.05). The results suggest that enhancement or impairment of cholinergic activity preferentially influences the maintenance of selective attention (ie trials greater than 1). Moreover, effects of cholinergic manipulation depend on the selective attention condition (ie faces vs houses), which may suggest that cholinergic activity interacts with stimulus salience. The findings are discussed within the context of the role of acetylcholine both in stimulus processing and stimulus salience, and in establishing attention biases through top-down and bottom-up mechanisms of attention.Maura L. FureyPietro Pietrinipietro.pietrini@imtlucca.itJames V. HaxbyWayne C. Drevets2016-02-22T12:40:05Z2016-02-22T12:40:05Zhttp://eprints.imtlucca.it/id/eprint/3112This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/31122016-02-22T12:40:05ZSelective Effects of Cholinergic Modulation on Task Performance during Selective AttentionThe cholinergic neurotransmitter system is critically linked to cognitive functions including attention. The current studies were designed to evaluate the effect of a cholinergic agonist and an antagonist on performance during a selective visual attention task where the inherent salience of attended/unattended stimuli was modulated. Two randomized, placebo-controlled, crossover studies were performed, one (n=9) with the anticholinesterase physostigmine (1.0 mg/h), and the other (n=30) with the anticholinergic scopolamine (0.4 mc/kg). During the task, two double-exposure pictures of faces and houses were presented side by side. Subjects were cued to attend to either the face or the house component of the stimuli, and were instructed to perform a matching task with the two exemplars from the attended category. The cue changed every 4–7 trials to instruct subjects to shift attention from one stimulus component to the other. During placebo in both studies, reaction time (RT) associated with the first trial following a cued shift in attention was longer than RT associated with later trials (p<0.05); RT also was significantly longer when attending to houses than to faces (p<0.05). Physostigmine decreased RT relative to placebo preferentially during trials greater than one (p<0.05), with no change during trial one; and decreased RT preferentially during the attention to houses condition (p<0.05) vs attention to faces. Scopolamine increased RT relative to placebo selectively during trials greater than one (p<0.05), and preferentially increased RT during the attention to faces condition (p<0.05). The results suggest that enhancement or impairment of cholinergic activity preferentially influences the maintenance of selective attention (ie trials greater than 1). Moreover, effects of cholinergic manipulation depend on the selective attention condition (ie faces vs houses), which may suggest that cholinergic activity interacts with stimulus salience. The findings are discussed within the context of the role of acetylcholine both in stimulus processing and stimulus salience, and in establishing attention biases through top-down and bottom-up mechanisms of attention.Maura L. FureyPietro Pietrinipietro.pietrini@imtlucca.itJames V. HaxbyWayne C. Drevets2016-02-22T11:11:21Z2016-09-13T09:57:42Zhttp://eprints.imtlucca.it/id/eprint/3106This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/31062016-02-22T11:11:21ZIs visual experience necessary for the functional development of the mirror neuron system? An fMRI study in sighted and congenitally blind individualsDaniela BoninoEmiliano Ricciardiemiliano.ricciardi@imtlucca.itLorenzo SaniTomaso VecchiMario GuazzelliJames V. HaxbyLuciano FadigaPietro Pietrinipietro.pietrini@imtlucca.it2016-02-22T10:50:55Z2016-09-13T09:57:53Zhttp://eprints.imtlucca.it/id/eprint/3103This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/31032016-02-22T10:50:55ZMotor familiarity modulates mirror neurons system activity during auditory action recognition in sighted and congenitally blind individualsDaniela BoninoEmiliano Ricciardiemiliano.ricciardi@imtlucca.itLorenzo SaniTomaso VecchiMario GuazzelliJames V. HaxbyLuciano FadigaPietro Pietrinipietro.pietrini@imtlucca.it2016-02-22T10:48:55Z2016-09-13T10:02:18Zhttp://eprints.imtlucca.it/id/eprint/3102This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/31022016-02-22T10:48:55ZFunctional development of the mirror neuron system does not require visual experience: an fMRI study in sighted and congenitally blind individualsEmiliano Ricciardiemiliano.ricciardi@imtlucca.itDaniela BoninoLorenzo SaniTomaso VecchiMario GuazzelliJames V. HaxbyLuciano FadigaPietro Pietrinipietro.pietrini@imtlucca.it2016-02-19T12:42:01Z2016-09-13T10:00:28Zhttp://eprints.imtlucca.it/id/eprint/3090This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/30902016-02-19T12:42:01ZDifferential modulation of neural activity throughout the distributed neural system for face perception in patients with Social Phobia and healthy subjectsSocial Phobia (SP) is a marked and persistent fear of social or performance situations in which the person is exposed to unfamiliar people or to possible scrutiny by others. Faces of others are perceived as threatening by social phobic patients (SPP). To investigate how face processing is altered in the distributed neural system for face perception in Social Phobia, we designed an event-related fMRI study in which Healthy Controls (HC) and {SPP} were presented with angry, fearful, disgusted, happy and neutral faces and scrambled pictures (visual baseline). As compared to HC, {SPP} showed increased neural activity not only in regions involved in emotional processing including left amygdala and insula, as expected from previous reports, but also in the bilateral superior temporal sulcus (STS), a part of the core system for face perception that is involved in the evaluation of expression and personal traits. In addition {SPP} showed a significantly weaker activation in the left fusiform gyrus, left dorsolateral prefrontal cortex, and bilateral intraparietal sulcus as compared to HC. These effects were found not only in response to emotional faces but also to neutral faces as compared to scrambled pictures. Thus, {SPP} showed enhanced activity in brain areas related to processing of information about emotional expression and personality traits. In contrast, brain activity was decreased in areas for attention and for processing other information from the face, perhaps as a result of a feeling of wariness. These results indicate a differential modulation of neural activity throughout the different parts of the distributed neural system for face perception in {SPP} as compared to HC.Claudio GentiliMaria Ida GobbiniEmiliano Ricciardiemiliano.ricciardi@imtlucca.itNicola VanelloPietro Pietrinipietro.pietrini@imtlucca.itJames V. HaxbyMario Guazzelli2016-02-19T12:34:59Z2016-09-13T10:01:01Zhttp://eprints.imtlucca.it/id/eprint/3087This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/30872016-02-19T12:34:59ZImbalanced between attentional and emotional system in social phobics processing social relevant stimulliClaudio GentiliMaria Ida GobbiniEmiliano Ricciardiemiliano.ricciardi@imtlucca.itNicola VanelloPietro Pietrinipietro.pietrini@imtlucca.itJames V. HaxbyMario Guazzelli2016-02-19T12:23:22Z2016-09-13T10:00:47Zhttp://eprints.imtlucca.it/id/eprint/3083This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/30832016-02-19T12:23:22ZImbalanced activation of the distributed neural system for face perception in social phobiaClaudio GentiliMaria Ida GobbiniEmiliano Ricciardiemiliano.ricciardi@imtlucca.itNicola VanelloPietro Pietrinipietro.pietrini@imtlucca.itJames V. HaxbyMario Guazzelli2015-12-23T15:17:45Z2016-09-13T09:55:21Zhttp://eprints.imtlucca.it/id/eprint/2976This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/29762015-12-23T15:17:45ZDo we really need vision? How blind people "see" the actions of othersObserving and learning actions and behaviors from others, a mechanism crucial for survival and social interaction, engages the mirror neuron system. To determine whether vision is a necessary prerequisite for the human mirror system to develop and function, we used functional magnetic resonance imaging to compare brain activity in congenitally blind individuals during the auditory presentation of hand-executed actions or environmental sounds, and the motor pantomime of manipulation tasks, with that in sighted volunteers, who additionally performed a visual action recognition task. Congenitally blind individuals activated a premotor–temporoparietal cortical network in response to aurally presented actions that overlapped both with mirror system areas found in sighted subjects in response to visually and aurally presented stimuli, and with the brain response elicited by motor pantomime of the same actions. Furthermore, the mirror system cortex showed a significantly greater response to motor familiar than to unfamiliar action sounds in both sighted and blind individuals. Thus, the mirror system in humans can develop in the absence of sight. The results in blind individuals demonstrate that the sound of an action engages the mirror system for action schemas that have not been learned through the visual modality and that this activity is not mediated by visual imagery. These findings indicate that the mirror system is based on supramodal sensory representations of actions and, furthermore, that these abstract representations allow individuals with no visual experience to interact effectively with others.Emiliano Ricciardiemiliano.ricciardi@imtlucca.itDaniela BoninoLorenzo SaniTomaso VecchiMario GuazzelliJames V. HaxbyLuciano FadigaPietro Pietrinipietro.pietrini@imtlucca.it2015-12-02T15:24:06Z2016-09-13T09:55:03Zhttp://eprints.imtlucca.it/id/eprint/2958This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/29582015-12-02T15:24:06ZBeyond amygdala: default mode network activity differs between patients with social phobia and healthy controlsThe Default Mode Network (DMN) is a constellation of brain areas that decrease their activity during a wide number of different goal-oriented tasks as compared to passive “rest” tasks. {DMN} can be modulated by different factors such as emotional states, cognitive load of the task and psychopathology, including anxiety. Moreover, {DMN} seems to play a pivotal role in social cognition. For example, the ability to predict another person's behaviour taking his or her perspective modulates the activity of the DMN. Recent data from autistic patients support a role of {DMN} in social cognition as well. Social Phobia (SP) is an anxiety disorder characterized by an abnormal distress in situations that require social interaction. To date, no study has assessed {DMN} in Social Phobia. To determine potential differences in {DMN} activity between Social Phobia patients (SPP) and healthy control (HC) subjects we examined functional magnetic resonance imaging (fMRI) data obtained during a face perception study with emotional and neutral stimuli. As compared to HC, {SPP} showed a lower deactivation in the precuneus and posterior cingulate regions (PCun/PCC) during task conditions. These regions are part of the so-called “Theory of Mind” circuit and in particular they are involved in the evaluation of one's own emotional state. Because of the role of the PCun/PCC in self-state perception and attribution and, more in general, the role of the {DMN} in social cognition, we suggest that its impairment in the {DMN} network in {SPP} might be relevant in the development of the feeling of wariness of others’ judgment and may be related to the so-called self-focused attention. Self-focused attention is the awareness of self-referent information, and is present in many emotional disorders and may additionally prevent individuals from observing external information that could disconfirm their own fears. Moreover, the abnormal modulation of activity in the {DMN} may reflect persistent rumination or anxiety-related thoughts that are not modulated by the switch from rest to task.Claudio GentiliEmiliano Ricciardiemiliano.ricciardi@imtlucca.itMaria Ida GobbiniMaria Filomena SantarelliJames V. HaxbyPietro Pietrinipietro.pietrini@imtlucca.itMario Guazzelli2015-11-18T11:19:55Z2016-09-13T09:54:19Zhttp://eprints.imtlucca.it/id/eprint/2922This item is in the repository with the URL: http://eprints.imtlucca.it/id/eprint/29222015-11-18T11:19:55ZCholinergic Effects in Visual Areas during Object and Spatial Working Memory Encoding: an fMRI studyGiacomo HandjarasEmiliano Ricciardiemiliano.ricciardi@imtlucca.itJames V. HaxbyPietro Pietrinipietro.pietrini@imtlucca.itMaura L. Furey