Camillo Marra

Publications (84) View all

• Source

  Available from: Guido Gainotti

  Article: The evaluation of sources of knowledge underlying different conceptual categories.

  Guido Gainotti, Pietro Spinelli, Eugenia Scaricamazza, Camillo Marra
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  ABSTRACT: According to the "embodied cognition" theory and the "sensory-motor model of semantic knowledge": (a) concepts are represented in the brain in the same format in which they are constructed by the sensory-motor system and (b) various conceptual categories differ according to the weight of different kinds of information in their representation. In this study, we tried to check the second assumption by asking normal elderly subjects to subjectively evaluate the role of various perceptual, motor and language-mediated sources of knowledge in the construction of different semantic categories. Our first aim was to rate the influence of different sources of knowledge in the representation of animals, plant life and artifact categories, rather than in living and non-living beings, as many previous studies on this subject have done. We also tried to check the influence of age and stimulus modality on these evaluations of the "sources of knowledge" underlying different conceptual categories. The influence of age was checked by comparing results obtained in our group of elderly subjects with those obtained in a previous study, conducted with a similar methodology on a sample of young students. And the influence of stimulus modality was assessed by presenting the stimuli in the verbal modality to 50 subjects and in the pictorial modality to 50 other subjects. The distinction between "animals" and "plant life" in the "living" categories was confirmed by analyzing their prevalent sources of knowledge and by a cluster analysis, which allowed us to distinguish "plant life" items from animals. Furthermore, results of the study showed: (a) that our subjects considered the visual modality as the main source of knowledge for all categories taken into account; and (b) that in biological categories the next most important source of information was represented by other perceptual modalities, whereas in artifacts it was represented by the actions performed with them. Finally, age and stimulus modality did not significantly influence judgment of relevance of the sources of knowledge involved in the construction of different conceptual categories.
  Frontiers in Human Neuroscience 01/2013; 7:40. · 2.34 Impact Factor
• Article: Asymmetries in gender-related familiarity with different semantic categories. Data from normal adults.

  Guido Gainotti, Pietro Spinelli, Eugenia Scaricamazza, Camillo Marra
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  ABSTRACT: The mechanisms subsuming the brain organization of categories and the corresponding gender related asymmetries are controversial. Some authors believe that the brain organization of categories is innate, whereas other authors maintain that it is shaped by experience. According to these interpretations, gender-related asymmetries should respectively be inborn or result from the influence of social roles. In a previous study, assessing the familiarity of young students with different 'biological' and 'artefact' categories, we had observed no gender-related difference on any of these categories. Since these data could be due to the fact that our students belonged to a generation in which the traditional social roles have almost completely disappeared, we predicted that gender-related asymmetries should be found in older men and women. The familiarity of young and elderly men and women with various semantic categories was, therefore, studied presenting in the verbal and pictorial modality different kinds of living and artefact categories. Results confirmed the hypothesis, because elderly women showed a greater familiarity for flowers and elderly men for animals. These findings are consistent with the hypothesis assuming that gender-related asymmetries for different semantic categories is due to the influence of gender-related social roles.
  Behavioural neurology 12/2012; · 1.77 Impact Factor
• Article: Mild Cognitive Impairment: Same Identity for Different Entities.

  Laura Serra, Giovanni Giulietti, Mara Cercignani, Barbara Spanò, Mario Torso, Diana Castelli, Roberta Perri, Lucia Fadda, Camillo Marra, Carlo Caltagirone, Marco Bozzali
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  ABSTRACT: This study investigates whether different patterns of grey matter (GM) loss may account for the different neuropsychological profiles observed in patients with amnestic (a-) and non-amnestic (na-) mild cognitive impairment (MCI), and may predict patients' clinical evolution. Fifty-five consecutive individuals complaining of cognitive dysfunction (referred to specialist dementia clinics) were screened and included in the study if they met the diagnostic criteria for MCI on a neurodegenerative basis. After an extensive neuropsychological assessment, patients were classified as suffering from a-MCI or na-MCI. Twenty-eight healthy individuals were also recruited and served as controls. All participants underwent magnetic resonance imaging at 3T, including conventional images and volumetric scans. Volumetric data were processed using voxel-based morphometry to assess between-group differences in regional GM volumes and correlations with neuropsychological performances. When compared to controls, a-MCI patients showed prominent GM volume reductions in the medial temporal lobes, while those with na-MCI showed reduced GM volumes in the orbito-frontal cortex and basal ganglia. In a-MCI patients, significant associations were found between verbal long-term memory performance and GM volumes in the hippocampus. Conversely, in na-MCI patients, associations were found between scores at tests exploring executive functions and GM volumes in the orbitofrontal cortex. At one-year follow-up, conversions were recorded exclusively toward Alzheimer's disease (AD) in the a-MCI group, and toward non-AD dementia in the na-MCI group. This study confirms that MCI is a heterogeneous clinical identity including different neurodegenerative entities; specific patterns of regional GM loss appear to account for specific neuropsychological features and are likely to predict patients' clinical evolution.
  Journal of Alzheimer's disease: JAD 10/2012; · 3.74 Impact Factor
• Article: Performing prototype distortion tasks requires no contribution from the explicit memory systems: Evidence from amnesic MCI patients in a new experimental paradigm.

  Gian Daniele Zannino, Roberta Perri, Silvia Zabberoni, Carlo Caltagirone, Camillo Marra, Giovanni A Carlesimo
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  ABSTRACT: Evidence shows that amnesic patients are able to categorize new exemplars drawn from the same prototype as in previously encountered items. It is still unclear, however, whether this ability is due to a spared implicit learning system or residual explicit memory and/or working memory resources. In this study, we used a new paradigm devised expressly to rule out any possible contribution of episodic and working memory in performing a prototype distortion task. We enrolled patients with amnesic MCI and Normal Controls. Our paradigm consisted of a study phase and a test phase; two-thirds of the participants performed the study phase and all participants performed the test phase. In the study phase, participants had to judge how pleasant morphed faces, drawn from a single prototype, seemed to them. Half of the participants were shown faces drawn from the A-prototype and half from the B-prototype. A- and B-faces were opposite in a morphing space with a neutral human face at the center. In the test phase, participants had to judge the regularity of faces they had never seen before. Three different types of faces were shown in the test phase, that is, A-, B-, or neutral-faces. We expected that implicit learning of the category boundaries would lead to a category-specific increase in perceived regularity. The results confirmed our predictions. In fact, trained subjects (compared with subjects who did not undergo the study phase) assigned higher regularity scores to new faces drawn from the same prototype as the faces seen during training, and they gave lower regularity scores to new faces drawn from the opposite prototype. This effect was super imposable across subjects' groups.
  Neuropsychologia 09/2012; 50(12):2907-15. · 3.64 Impact Factor
• Article: Brain tissue modifications induced by cholinergic therapy in Alzheimer's disease.

  Marco Bozzali, Geoff J M Parker, Barbara Spanò, Laura Serra, Giovanni Giulietti, Roberta Perri, Giuseppe Magnani, Camillo Marra, Maria G Vita, Carlo Caltagirone, Mara Cercignani
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  ABSTRACT: A previous preliminary investigation based on a novel MRI approach to map anatomical connectivity revealed areas of increased connectivity in Alzheimer's disease (AD) but not in mild cognitive impairment patients. This prompted the hypothesis tested here, that these areas might reflect phenomena of brain plasticity driven by acetylcholinesterase inhibitors (AChEIs). Thirty-eight patients with probable AD (19 under medication with AChEIs and 19 drug-naïve) were recruited together with 11 healthy controls. All subjects had MRI scanning at 3T, including volumetric and diffusion-weighted scans. Probabilistic tractography was used to initiate streamlines from all parenchymal voxels, and anatomical connectivity maps (ACMs) were obtained by counting, among the total number of streamlines initiated, the fraction passing through each brain voxel. After normalization into standard space, ACMs were used to test for between-group comparisons, and for interactions between the exposure to AChEIs and global level of cognition. Patients with AD had reduced ACM values in the fornix, cingulum, and supramarginal gyri. The ACM value was strongly associated with the AChEI dosage-x-duration product in the anterior limb (non-motor pathway) of the internal capsule. Tractography from this region identified the anterior thalamic radiation as the main white matter (WM) tract passing through it. The reduced connectivity in WM bundles connecting the hippocampi with the rest of the brain (fornix/cingulum) suggests a possible mechanism for the spread of AD pathology. An intriguing explanation for the interaction between AChEIs and ACM is related to the mechanisms of brain plasticity, partially driven by neurotrophic properties of acetylcholine replacement. Hum Brain Mapp, 2012. © 2012 Wiley Periodicals, Inc.
  Human Brain Mapping 06/2012; · 5.88 Impact Factor