12 research outputs found

    Neurocognitve Dimensions of Self-consciousness

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    Abstract: Self-consciousness is considered in a framework comprising four dimensions which are theoretically defined and supported by clinical neuropsychological evidence. Self-monitoring is defined as the ability to reflect on one’s own behaviour, with supporting evidence for deficits in this capacity noted in anosognosia syndrome. Self-feeling is defined as the capacity to feel all sensations related to one’s own body (interoception and exteroception), with supporting evidence from deficiencies occurring in alexithymia, psychosomatic states and Cotard’s delusion. Identity refers to the capacity to recognize an object as identical to oneself, based on autobiographic memory; pathological conditions related to this dimension include delusions of identity and the Zelig syndrome. Ownership is the capacity to perceive the status of ones’ own body, and is clinically altered in somatoparaphrenia. All four dimensions are related to specific brain networks.Keywords: Self-Monitoring; Self-Feeling; Identity; Ownership; Neurocognitive Dimensions Le dimensioni neurocognitive dell’autocoscienza Riassunto: L’autocoscienza viene inquadrata in base a quattro dimensioni, determinate in via teorica e supportate da evidenze cliniche di carattere neuropsicologico. L’automonitoraggio Ăš definito quale capacitĂ  di riflettere sul proprio comportamento ed Ăš sostenuto da evidenze che derivano da quella sindrome denominata anosognosia. Il sentire il proprio sĂ© Ăš la capacitĂ  di avvertire tutte le sensazioni del corpo proprio (interocettive ed esterocettive); questa dimensione Ăš supportata da evidenze derivanti da condizioni cliniche quali l’alessitimia, le affezioni psicosomatiche e il delirio di Cotard. L’identitĂ  si riferisce alla capacitĂ  di riconoscere come identico a se stesso un oggetto, fondata sulla memoria autobiografica; le condizioni patologiche legate a questa dimensione sono il delirio di identitĂ  e la sindrome di Zelig. Il possesso di sĂ© Ăš la capacitĂ  di percepire lo stato del proprio corpo, condizione che risulta alterata nella somatoparafrenia. Tutte queste quattro dimensioni sono collegate a specifici network cerebrali.Parole chiave: Automonitoraggio; Sentimento di sĂ©; IdentitĂ ; Padronanza di sĂ©; Dimensioni neurocognitiv

    Fronto-Temporal Circuits in Musical Hallucinations: A PET-MR Case Study

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    The aim of the study is to investigate morphofunctional circuits underlying musical hallucinations (MH) in a 72-years old female that underwent a simultaneous 18fluoredeoxyglucose positron emission tomography (PET) and advanced magnetic resonance (MR) exam. This represents a particular case of MH occurred in an healthy subject, not displaying neurological or psychopathological disorders, and studied simultaneously with a multimodal approach. For the resting-state fMRI analysis a seed to seed approach was chosen. For the task-based fMRI, 4 different auditory stimuli were presented. Imaging findings were compared with data obtained by ten healthy controls matched for age and sex. Neuropsychological evaluation and questionnaires investigating depression and anxiety were also administered. PET findings showed hypermetabolism of: superior temporal gyri, anterior cingulate, left orbital frontal, and medial temporal cortices. Structural MRI did not show macroscopical lesions except for gliotic spots along the uncinate fascicle pathways with an increased cortical thickness for the right orbitofrontal cortex (p = 0.003). DTI showed increased fractional anisotropy values in the left uncinate fascicle, when compared to controls (p = 0.04). Resting-state fMRI showed increased functional connectivity between the left inferior frontal gyrus and the left temporal fusiform cortex (p = 0.01). Task-based fMRI confirmed PET findings showing an increased activation of the superior temporal gyrus in all the auditory tasks except for the monotone stimulus, with a significant activation of the left orbital frontal cortex only during the song in foreign language, object of MH. Results on cognitive test did not show cognitive impairment, excepting for the performance on Frontal Assessment Battery where the patient fails in the cognitive domains of conceptualization, sensitive to interference, and inhibitory control. The subject did not show depressive or anxiety symptoms. Summarizing, multimodal imaging analyses in the MH case showed a microstructural alteration of the left uncinate fascicle paralleled by an increased metabolism and functional connectivity of cortical regions that receive left uncinate projections (orbital frontal cortex, and medial temporal cortex). This alteration of fronto-hyppocampal circuits could be responsible of retrieval of known songs even in the absence of real stimuli

    Dopamine Treatment and Cognitive Functioning in Individuals with Parkinson’s Disease: The “Cognitive Flexibility” Hypothesis Seems to Work

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    Background. Previous data suggest that (i) dopamine modulates the ability to implement nonroutine schemata and update operations (flexibility processes) and that (ii) dopamine-related improvement may be related to baseline dopamine levels in target pathways (inverted U-shaped hypothesis). Objective. To investigate above hypotheses in individuals with Parkinson's disease (PD). Methods. Twenty PD patients were administered tasks varying as to flexibility load in two treatment conditions: (i) “off” condition, about 18 hours after dopamine dose and (ii) “on” condition, after dopamine administration. PD patients were separated into two groups: low performers (i.e., performance on Digit Span Backward below the sample mean) and high performers (i.e., performance above the mean). Twenty healthy individuals performed the tasks in two sessions without taking drugs. Results. Passing from the “off” to the “on” state, only low performer PD patients significantly improved their performance on high-flexibility measures (interference condition of the Stroop test; P<0.05); no significant effect was found on low-flexibility tasks. Conclusions. These findings document that high-flexibility processes are sensitive to dopamine neuromodulation in the early phases of PD. This is in line with the hypothesis that striatal dopamine pathways, affected early by PD, are precociously implicated in the expression of cognitive disorders in these individuals

    Dopamine Treatment and Cognitive Functioning in Individuals with Parkinson’s Disease: The “Cognitive Flexibility” Hypothesis Seems to Work

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    Background. Previous data suggest that (i) dopamine modulates the ability to implement nonroutine schemata and update operations (flexibility processes) and that (ii) dopamine-related improvement may be related to baseline dopamine levels in target pathways (inverted U-shaped hypothesis). Objective. To investigate above hypotheses in individuals with Parkinson's disease (PD). Methods. Twenty PD patients were administered tasks varying as to flexibility load in two treatment conditions: (i) “off” condition, about 18 hours after dopamine dose and (ii) “on” condition, after dopamine administration. PD patients were separated into two groups: low performers (i.e., performance on Digit Span Backward below the sample mean) and high performers (i.e., performance above the mean). Twenty healthy individuals performed the tasks in two sessions without taking drugs. Results. Passing from the “off” to the “on” state, only low performer PD patients significantly improved their performance on high-flexibility measures (interference condition of the Stroop test; P<0.05); no significant effect was found on low-flexibility tasks. Conclusions. These findings document that high-flexibility processes are sensitive to dopamine neuromodulation in the early phases of PD. This is in line with the hypothesis that striatal dopamine pathways, affected early by PD, are precociously implicated in the expression of cognitive disorders in these individuals

    Altered functional connectivity of interoception in illness anxiety disorder

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    nteroception collects all information coming from the body and is sustained by several brain areas such as insula and cingulate cortex. Here, we used resting-state functional magnetic resonance imaging to investigate functional connectivity (FC) of networks implied in interoception in patients with Illness anxiety disorders (IADs). We observed significantly reduced FC between the left extrastriate body area (EBA) and the paracentral lobule compared to healthy controls. Moreover, the correlation analysis between behavioural questionnaires and ROI to ROI FC showed that higher levels of illness anxiety were related to hyper-connectivity between EBA and amygdala and hippocampus. Scores on a questionnaire for interoceptive awareness were significantly correlated with higher FC between right hippocampus and nucleus accumbens bilaterally, and with higher connectivity between left anterior cingulate cortex (ACC) and left orbitofrontal cortex (OFC). Last, patients showed increased interoceptive awareness, measured by Self-Awareness Questionnaire (SAQ), and reduced capability in recognizing emotions, indicating inverse correlation between interoception and emotional awareness. Taken together our results suggested that, in absence of structural and micro-structural changes, patients with IADs show functional alteration in the neural network involved in the self-body representation; such functional alteration might be the target of possible treatments

    The influence of interoceptive awareness on functional connectivity in patients with irritable bowel syndrome

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    Irritable bowel syndrome (IBS) is characterized by visceral hypersensitivity likely related to altered processing of sensory stimuli along the brain-gut axis. Previous neuroimaging studies demonstrated structural and functional alteration of several brain areas involved in bodily representation, e.g. the insula, in patients with IBS. By means of resting-state functional magnetic resonance imaging (rs-fMRI) we searched for alteration of functional connectivity within the network involved in self-bodily consciousness. We found significant inverse correlation between hypochondriasis assessed through a clinical questionnaire and connectivity between posterior cingulate cortex and left supramarginal gyrus, extending into the adjacent superior temporal gyrus. Moreover, we observed a significant and positive correlation between a clinical questionnaire assessing interoception and connectivity between left anterior ventral insula and two clusters located in supramarginal gyrus bilaterally. Our findings highlight an “abnormal network synchrony” reflecting functional alteration, in the absence of structural and micro-structural changes, which might represent a possible therapeutic target for Irritable Bowel Syndrome
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