| Name | Dario |
| Surname | Grossi |
| Institution | Università degli Studi della Campania Luigi Vanvitelli |
| dario.grossi@unicampania.it | |
| Address | Villa Camaldoli Foundation Clinic, Naples, Italy; Department of Psychology, University of Campania "Luigi Vanvitelli", Napoli, Italy |
: Subjects can improve their performance on memory for action phrases if, during the encoding condition, they self-perform actions associated with verbs (subject-performed condition), or if they perceive the actions carried out by experimenter (experimenter-performed condition), with respect to a verbal task condition in which they only read or listen to the stimuli. This facilitation is labeled "Enactment effect" (EE), and is thought to be associated with episodic integration processes binding actions and nouns together in a coherent representation. Only recently, studies addressed EE in AD individuals reporting significant improvements on memory tasks in the subject-performed encoding condition. However, no studies tried to explore the cognitive mechanisms supporting EE in AD individuals. : Performance on recognition and cued recall tasks for action phrases were assessed in a sample of 32 mild-to-moderate AD individuals and 30 healthy adults, in verbal, subject-performed and experimenter-performed encoding conditions. Moreover, a cognitive assessment was completed to explore the possible correlates of EE in our participants. : Results showed that both subject-performed and experimenter-performed encoding conditions produced similar advantages over the verbal condition, in both memory tasks in both groups. Moreover, these memory advantages were strongly associated to executive processes, in both AD and healthy adults. : The present study confirmed that EE is spared in mild to moderate AD. Our findings supported the role of episodic integration processes and suggested a contribution of executive processes in EE.
Interoception consists in the perception and processing of internal body signals, such as heartbeat. Previous neuroimaging studies revealed that attention to heartbeat activated bilateral insula and premotor regions. In the present double-blind study, we aimed at testing the role of insula in interoception by means of transcranial direct current stimulation (tDCS) interfering with its activity. Sixteen healthy participants responded to a questionnaire to evaluate the tendency to be internally focused and performed a heartbeat counting task before and after tDCS in three sessions (left insula stimulation, right insula stimulation, sham stimulation). Real and reported heartbeat were recorded and used to calculate the accuracy scores. A significant interaction between stimulation condition and time (pre- and post-stimulation) was found due to a significant improvement of the interoceptive accuracy in the sham condition only. Our results demonstrated that stimulation over the insula reduced the possibility to improve the precision with which individuals detect internal signals.
Prism Adaptation (PA) represents a valid tool to assess short-term visuomotor plasticity. Two adaptive processes are involved during PA: recalibration, contributing to early error compensation, and spatial realignment, contributing to after-effect development. Classical models on PA posit that adaptive mechanisms underlying PA rely on segregated regions in the brain. Indeed, they ascribe recalibration to the activity of the Posterior Parietal Cortex (PPC) and spatial realignment to the activity of the Cerebellum. The present experiment challenges the idea of a clear-cut separation of the role of the brain areas involved in PA, proposing an interpretation in terms of interrelated brain regions. To this purpose we interfered with the activity of the PPC and the Cerebellum by means of complementary protocols of stimulation. Bi-cephalic transcranial Direct Current Stimulation was delivered simultaneously on the PPC and the Cerebellum during PA in two groups of participants receiving real stimulation with opposite polarities (anode on PPC and cathode on Cerebellum or vice-versa) and in a control group (Sham stimulation). Differences in mean errors between groups were analyzed. Results show that the two groups of real stimulation exhibited larger displacements in early error compensation compared to the Sham Group, but they did not differ from each other. No group difference was found in late error compensation and after-effect. In conclusion, the present findings provide the first direct evidence that a brain circuit connecting the PPC and the Cerebellum is involved in early stages of visuomotor adaptation, and pave the way for updating classical models of PA.
Previous studies showed that motor information related to tool use (i.e., functional actions) could affect processing of objects semantic properties, whereas motor information related to grasping or moving tool (i.e., structural actions) cannot. However, little is known about the neural correlates mediating such interaction between motor and semantic information. Here, healthy participants performed a semantic judgment task requiring identification of semantic relations among objects, after observing a functional, a structural or a pointing action prime. In a within-subject design, during prime presentation the participants underwent repetitive transcranial magnetic stimulation (rTMS) over the left supramarginal gyrus (SMG), the left posterior middle temporal gyrus (pMTG) or received sham stimulation. Results showed that in the sham condition observing functional actions (vs. structural and pointing actions) favoured processing of semantic relations based on function similarity (i.e., taxonomic relations), but not of relations based on co-occurrence within an event schema (i.e., thematic relations). Moreover, stimulation of both left SMG and pMTG abolished the effect of functional action primes worsening subsequent judgment about taxonomic relations, and this effect was greater after pMTG stimulation. rTMS did not affect processing of thematic semantic relations. We suggest that action observation triggers activation of functional motor information within left inferior parietal cortex, and that integration between functional motor and conceptual information in left temporal cortex could impact high-level semantic processing of tools.
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 ( = 0.003). DTI showed increased fractional anisotropy values in the left uncinate fascicle, when compared to controls ( = 0.04). Resting-state fMRI showed increased functional connectivity between the left inferior frontal gyrus and the left temporal fusiform cortex ( = 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.
Apathy is commonly reported in Alzheimer's Disease (AD), Fronto-Temporal Dementia (FTD) and Parkinson's Disease (PD). In our meta-analysis we analysed a total of 41 studies to identify brain patterns associated with apathy. For these purposes we used activation likelihood estimation meta-analyses. Our main overall analysis showed that apathy is associated to hypometabolism and a decreased gray matter volume in the left inferior frontal gyrus (BA 45, 46). Disorder-specific analyses, not performed by means of meta-analysis, because of the small number of studies, but by means a label-based review, revealed an altered brain perfusion and decreased gray matter volume in anterior cingulate cortex (BA 24, 32) in AD patients and a decreased gray matter volume in inferior frontal gyrus (BA 44, 45) and parietal cortex (BA 40) in FTD patients. These findings suggest that apathy is mainly associated with a cortical dysfunction of areas involved in executive-cognitive processing (i.e. action planning) and emotional regulation (auto-activation and reward processing). Knowledge about the neural underpinnings of apathy is crucial for understanding its clinical characteristics in neurodegenerative diseases and for developing novel strategies of treatment in clinical practice.
Few studies examined the effects of combined motor and cognitive rehabilitation in patients with multiple sclerosis (MS). The present prospective, multicenter, observational study aimed to determine the efficacy of an integrated cognitive and neuromotor rehabilitation program versus a traditional neuromotor training on walking, balance, cognition and emotional functioning in MS patients. Sixty three MS patients were selected and assigned either to the Integrated Treatment Group (ITG; = 32), receiving neuropsychological treatment (performed by ERICA software and paper-pencil tasks) complemented by conventional neuromotor rehabilitation, or to the Motor Treatment Group ( = 31) receiving neuromotor rehabilitation only. The intervention included two 60-min sessions per week for 24 weeks. At baseline and at end of the training all patients underwent a wide-range neuropsychological, psychological/emotional, and motor assessment. At baseline the two groups did not differ for demographic, neuropsychological, psychological/emotional, and motor features significantly. After rehabilitation, only ITG group significantly ( for False Discovery Rate) improved on test tapping spatial memory, attention and cognitive flexibility, as well as on scales assessing depression and motor performance (balance and gait). A regression analysis showed that neuropsychological and motor improvement was not related to improvements in fatigue and depression. The present study demonstrated positive effects in emotional, motor, and cognitive aspects in MS patients who received an integrated cognitive and neuromotor training. Overall, results are supportive of interventions combining motor and cognitive training for MS.
Alzheimer's disease (AD) patients may show the Closing-in (CI), a tendency to reproduce figures close to or superimposed on the model. AD patients with CI might manifest reduced functional independence compared to AD patients without CI, but no study directly assessed if CI can hamper common daily living activities. To address this issue here we investigated whether AD patients with CI veer their walking trajectory toward irrelevant objects more often than AD patients without CI.
The extrastriate body area (EBA) is involved in perception of human bodies and nonfacial body parts, but its role in representing body identity is not clear. Here, we used on-line high-frequency repetitive transcranial magnetic stimulation (rTMS) to test the role of EBA in self-other distinction. In Experiments 1 and 2 we compared rTMS of right EBA with stimulation of left ventral premotor cortex (vPM), whereas in Experiment 3 we compared stimulation of right and left EBA. RTMS was applied during a hand laterality task in which self or others' hand images were presented in first- versus third-person view (Experiments 1 and 3), or while participants had to explicitly recognize their own hands (Experiment 2) presented in first- versus third-person view. Experiment 1 showed that right EBA stimulation selectively speeded judgments on others' hands, whereas no effect of left vPM stimulation was found. Experiment 2 did not reveal any effect of rTMS. Experiment 3 confirmed faster responses on others' hands while stimulating right EBA and also showed an advantage when judging self with respect to others' hands during stimulation of left EBA. These results would demonstrate that EBA responds to morphological features of human body contributing to identity processing.
Progranulin (GRN) gene mutations have been genetically associated with frontotemporal dementia (FTD) and are present in about 23% of patients with familial FTD. However, the neurobiology of this secreted glycoprotein remains unclear. Here, we report the identification of 3 pedigrees of Southern Italian extraction in whom FTD segregates with autosomal dominant inheritance patterns. We present evidence that all the available patients in these 3 familial cases are carrying the rare GRN gene exon 6 deletion g10325_10331delCTGCTGT (relative to nt 1 inNG_007886.1), alias Cys157LysfsX97. This mutation was previously described in 2 sporadic cases but was never associated with familial cases. Our patients demonstrate heterogeneous clinical phenotypes, such as the behavioral variant (bvFTD) in the affected men and the nonfluent/agrammatic variant of primary progressive aphasia (nfvPPA) in the affected woman. Haploinsufficiency was revealed by both quantitative real-time PCR of the gene and protein analyses. These findings provide further support for a previously proposed role for the GRN gene in the genetic etiology of FTD and its phenotypic variability.