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Background and Purpose: Performance on gambling tasks in Parkinson's disease (PD) is of particular interest, as pathological gambling is often associated with dopamine replacement therapy in these patients. We aimed to evaluate the effects of transcranial direct current stimulation (tDCS) over the right dorsolateral prefrontal cortex (DLPFC) in modulating gambling behaviour in PD., Methods: We assessed the effects of cathodal tDCS over the right DLPFC during the Iowa Gambling Task in 20 patients with PD, compared with sham stimulation. We then conducted a second experimental design, assessing the effects of anodal tDCS over the right DLPFC., Results: We observed that cathodal tDCS over the right DLPFC increased Iowa Gambling Task scores compared with sham stimulation. In the second experimental design, we did not find significant differences between anodal and sham tDCS., Conclusions: Cathodal tDCS over the right DLPFC possibly reduces the pathological overdrive in frontostriatal networks in patients with PD on dopaminergic medication, thus modulating impulsive and risky decision-making., (© 2017 EAN.)

Gender differences in social cognition are a long discussed issue, in particular those concerning Theory of Mind (ToM), i.e., the ability to explain and predict other people's mental states. The aim of this randomized, double-blind, placebo-controlled study was to test the hypothesis that anodal tDCS over the medial prefrontal cortex (mPFC) selectively enhances cognitive ToM performance in females. In the first experiment we administered to sixteen females and sixteen males a cognitive ToM task during anodal or placebo tDCS over the mPFC. In the second experiment further sixteen females completed the task receiving anodal or placebo tDCS over the vertex. The results showed that anodal tDCS over the mPFC enhances ToM in females but not in males, an effect indicated by enhanced ToM in females that received anodal tDCS over the mPFC compared with females that received tDCS over the vertex. These findings are relevant for three reasons. First, we found evidence of gender-related differences in cognitive ToM, extending previous findings concerning affective ToM. Second, these differences emerge with anodal stimulation of the mPFC, confirming the crucial role of this area in cognitive ToM. Third, we show that taking into account gender-related differences is mandatory for the investigation of ToM.

Episodic memory displays the largest degree of age-related decline. A noninvasive brain stimulation technique that can be used to modulate memory in physiological aging is transcranial Direct Current Stimulation (tDCS). However, an aspect that has not been adequately investigated in previous studies is the optimal timing of stimulation to induce long-lasting positive effects on episodic memory function. Our previous studies showed episodic memory enhancement in older adults when anodal tDCS was applied over the left lateral prefrontal cortex during encoding or after memory consolidation with or without a contextual reminder. Here we directly compared the two studies to explore which of the tDCS protocols would induce longer-lasting positive effects on episodic memory function in older adults. In addition, we aimed to determine whether subjective memory complaints would be related to the changes in memory performance (forgetting) induced by tDCS, a relevant issue in aging research since individuals with subjective memory complaints seem to be at higher risk of later memory decline. The results showed that anodal tDCS applied after consolidation with a contextual reminder induced longer-lasting positive effects on episodic memory, conceivably through reconsolidation, than anodal tDCS during encoding. Furthermore, we reported, providing new data, a moderate negative correlation between subjective memory complaints and forgetting when anodal tDCS was applied after consolidation with a contextual reminder. This study sheds light on the best-suited timing of stimulation to induce long-lasting positive effects on memory function and might help the clinicians to select the most effective tDCS protocol to prevent memory decline., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Parkinson's disease (PD) is characterized by both motor and cognitive deficits. In PD, physical exercise has been found to improve physical functioning. Recent studies demonstrated that repeated sessions of transcranial direct current stimulation led to an increased performance in cognitive and motor tasks in patients with PD., Objectives: The present study investigated the effects of anodal transcranial direct current stimulation applied over the dorsolateral prefrontal cortex and combined with physical therapy in PD patients., Methods: A total of 20 patients with PD were assigned to 1 of 2 study groups: group 1, anodal transcranial direct current stimulation plus physical therapy (n = 10) or group 2, placebo transcranial direct current stimulation plus physical therapy (n = 10). The 2 weeks of treatment consisted of daily direct current stimulation application for 25 minutes during physical therapy. Long-term effects of treatment were evaluated on clinical, neuropsychological, and motor task performance at 3-month follow-up., Results: An improvement in motor abilities and a reduction of depressive symptoms were observed in both groups after the end of treatment and at 3-month follow-up. The Parkinson's Disease Cognitive Rating Scale and verbal fluency test performances increased only in the anodal direct current stimulation group with a stable effect at follow-up., Conclusions: The application of anodal transcranial direct current stimulation may be a relevant tool to improve cognitive abilities in PD and might be a novel therapeutic strategy for PD patients with mild cognitive impairment. © 2016 International Parkinson and Movement Disorder Society., (© 2016 International Parkinson and Movement Disorder Society.)

Episodic memory displays the largest degree of age-related decline, a process that is accelerated in pathological conditions such as amnestic mild cognitive impairment and Alzheimer's disease. Previous studies have shown that the left lateral prefrontal cortex (PFC) contributes to the encoding of episodic memories along the life span. The aim of this randomized, double-blind, placebo-controlled study was to test the hypothesis that anodal trascranial direct current stimulation (tDCS) over the left lateral PFC during the learning phase would enhance delayed recall of verbal episodic memories in elderly individuals. Older adults learned a list of words while receiving anodal or placebo (sham) tDCS. Memory recall was tested 48 hours and 1 month later. The results showed that anodal tDCS strengthened episodic memories, an effect indicated by enhanced delayed recall (48 hours) compared to placebo stimulation (Cohen's d effect size = 1.01). The observation that PFC-tDCS during learning can boost verbal episodic memory in the elderly opens up the possibility to design-specific neurorehabilitation protocols targeted to conditions that affect episodic memory such as mild cognitive impairment., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Episodic memory is a cognitive function that appears more susceptible than others to the effects of aging. The main aim of this study is to investigate if the magnitude of functional hemispheric lateralization during episodic memory test was positively correlated with memory performance, proving the presence of a beneficial pattern of neural processing in high-performing older adults but not in low-performing participants. We have applied anodal transcranial Direct Current Stimulation (tDCS) or sham stimulation over left and right hemisphere in a group of young subjects and in high-performing and low-performing older participants during an experimental verbal episodic memory task. Remarkably, young individuals and high-performing older adults exhibited similar performances on episodic memory tasks and both groups showed symmetrical recruitment of left and right areas during memory retrieval. In contrast, low-performing older adults, who obtained lower scores on the memory tasks, demonstrated a greater engagement of the left hemisphere during verbal memory task. Furthermore, structural equation model was performed for analyzing the interrelations between the index of interhemispheric asymmetry and several neuropsychological domains. We found that the bilateral engagement of dorsolateral prefrontal cortex and parietal cortex regions had a direct correlation with memory and executive functions evaluated as latent constructs. These findings drew attention to brain maintenance hypothesis. The potential of neurostimulation in cognitive enhancement is particularly promising to prevent memory loss during aging., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: Borderline personality disorder (BPD) is a chronic condition with a strong impact on patients' affective, cognitive and social functioning. Neuroimaging techniques offer invaluable tools to understand the biological substrate of the disease. We aimed to investigate gray matter alterations over the whole cortex in a group of Borderline Personality Disorder (BPD) patients compared to healthy controls (HC)., Methods: Magnetic resonance-based cortical pattern matching was used to assess cortical gray matter density (GMD) in 26 BPD patients and in their age- and sex-matched HC (age: 38 ± 11; females: 16, 61%)., Results: BPD patients showed widespread lower cortical GMD compared to HC (4% difference) with peaks of lower density located in the dorsal frontal cortex, in the orbitofrontal cortex, the anterior and posterior cingulate, the right parietal lobe, the temporal lobe (medial temporal cortex and fusiform gyrus) and in the visual cortex (P<0.005). Our BPD subjects displayed a symmetric distribution of anomalies in the dorsal aspect of the cortical mantle, but a wider involvement of the left hemisphere in the mesial aspect in terms of lower density. A few restricted regions of higher density were detected in the right hemisphere. All regions remained significant after correction for multiple comparisons via permutation testing., Conclusions: BPD patients feature specific morphology of the cerebral structures involved in cognitive and emotional processing and social cognition/mentalization, consistent with clinical and functional data., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Recent studies reported enhanced performance on language tasks induced by transcranial direct current stimulation (tDCS) in patients with aphasia. One chronic patient with non-fluent aphasia received 20 sessions of a verb anomia training combined with off-line bihemispheric tDCS applied to the dorsolateral prefrontal cortex (DLPFC) - anodal tDCS over left DLPFC plus cathodal tDCS over right DLPFC. A significant improvement in verb naming was observed at all testing times (4, 12, 24, and 48 weeks from post-entry/baseline testing) for treated and untreated verbs. Our findings show beneficial effects of verb anomia training in combination with tDCS in chronic aphasic patient, suggesting a long-lasting effect of this treatment.

Background: Word-retrieval difficulties are a common consequence of healthy ageing and are associated with a reduction in asymmetrical recruitment of the dorsolateral prefrontal cortex (DLPFC), although the significance of this reduction has not yet been clarified. Using repetitive transcranial magnetic stimulation (rTMS) it has been demonstrated that an asymmetrical involvement of the DLPFC during action naming in young subjects, whereas bilateral involvement was shown in elderly participants. By using rTMS during a naming task in a group of elderly subjects, the aim of the present work was to investigate whether the magnitude of DLPFC asymmetry (left-right rTMS effect) during action naming correlates with task performance, proving the presence of a compensation strategy in some but not all elderly participants., Methods: We aimed to test if there was a correlation between DLPFC asymmetry (left-right rTMS effect) and naming performance in a group of elderly subjects., Results: The results show that rTMS affects action naming differently according to individual naming ability. In particular, the predominance of a left vs. right DLPFC effect was observed only in the low-performing older adults, while an asymmetric reduction was selectively shown in the high-performing group. Interestingly, high-performing older adults also displayed better performances on a phonemic fluency test., Conclusion: The present data suggest that successful ageing is linked to less prefrontal asymmetry, an efficient strategy for counteracting age-related declines in cognitive function., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Background and Purpose: Progressive non-fluent aphasia (PNFA) is a neurodegenerative disorder that is characterized by non-fluent speech with naming impairment and grammatical errors. It has been recently demonstrated that repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) improves action naming in healthy subjects and in subjects with Alzheimer's disease., Purpose: To investigate whether the modulation of DLPFC circuits by rTMS modifies naming performance in patients with PNFA., Methods: Ten patients with a diagnosis of PNFA were enrolled. High-frequency rTMS was applied to the left and right DLPFC and the sham (i.e. placebo) condition during object and action naming. A subgroup of patients with semantic dementia was enrolled as a comparison group., Results: A repeated-measure anova with stimulus site (sham, left and right rTMS) showed significant effects. Action-naming performances during stimulation of both the left and right DLPFC were better than during placebo stimulation. No facilitating effect of rTMS to the DLPFC on object naming was observed. In patients with a diagnosis of semantic dementia, no effect of stimulation was reported., Conclusions: Our study demonstrated that rTMS improved action naming in subjects with PNFA, possibly due to the modulation of DLPFC pathways and a facilitation effect on lexical retrieval processes. Future studies on the potential of a rehabilitative protocol using rTMS applied to the DLPFC in this orphan disorder are required., (© 2012 The Author(s) European Journal of Neurology © 2012 EFNS.)

Functional neuroimaging studies have shown that younger adults tend to asymmetrically recruit specific regions of an hemisphere in an episodic memory task (Hemispheric Encoding Retrieval Asymmetry-HERA model). In older adults, this hemispheric asymmetry is generally reduced as suggested by the Hemispheric Asymmetry Reduction for OLDer Adults-HAROLD-model. Recent works suggest that while low-performing older adults do not show this reduced asymmetry, high-performing older adults counteract age-related neural decline through a plastic reorganization of cerebral networks that results in reduced functional asymmetry. However, the issue of whether high- and low-performing older adults show different degrees of asymmetry and the relevance of this process for counteracting aging have not been clarified. We used transcranial magnetic stimulation (TMS) to transiently interfere with the function of the dorsolateral prefrontal cortex (DLPFC) during encoding or retrieval of associated and non-associated word pairs. A group of healthy older adults was studied during encoding and retrieval of word pairs. The subjects were divided in two subgroups according to their experimental performance (i.e., high- and low-performing). TMS effects on retrieval differed according to the subject's subgroup. In particular, the predominance of left vs. right DLPFC effects during encoding, predicted by the HERA model, was observed only in low-performing older adults, while the asymmetry reduction predicted by the HAROLD model was selectively shown for the high-performing group. The present data confirm that older adults with higher memory performance show less prefrontal asymmetry as an efficient strategy to counteract age-related memory decline., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Transcranial direct current stimulation (tDCS) is able to generate a long-term increase or decrease in the neuronal excitability that can modulate cognitive tasks, similar to repetitive transcranial magnetic stimulation. The aim of this study was to explore the effects of tDCS on a language task in young healthy subjects. Anodal, cathodal and sham tDCS were applied to the left dorsolateral prefrontal cortex (DLPFC) before two picture naming experiments, a preliminary study (i.e., experiment 1) and a main study (i.e., experiment 2). The results show that anodal tDCS of the left DLPFC improves naming performance, speeding up verbal reaction times after the end of the stimulation, whereas cathodal stimulation had no effect. We hypothesize that the cerebral network dedicated to lexical retrieval processing is facilitated by anodal tDCS to the left DLPFC. Although the mechanisms responsible for facilitation are not yet clear, the results presented herein implicate a facilitation lasting beyond the end of the stimulation that imply cortical plasticity mechanisms. The opportunity to non-invasively interact with the functioning of these plasticity mechanisms will surely open new and promising scenarios in language studies in basic and clinical neuroscience fields., (Copyright 2010. Published by Elsevier B.V.)

The ability to associate a name to a face is a crucially relevant task in daily life. In this study, we investigated the neuronal basis of face-name retrieval in young subjects using repetitive transcranial magnetic stimulation (rTMS) over the left or right dorsolateral prefrontal cortex (DLPFC). The experimental task was composed of two study phases: an encoding phase and a retrieval phase. During the encoding phase, subjects saw a face (familiar or unfamiliar) followed by a name. During the retrieval phase, they saw the face together with two names and had to choose the name that was correctly associated with the face. rTMS was delivered only during retrieval. In addition, we evaluated the use of memory strategies during the task. Accordingly, subjects were subdivided into two groups: strategy users (SU) and no-strategy users (NSU). No rTMS effects were present for familiar face-name pairs, probably due to a ceiling effect. However, for unfamiliar face-name pairs, the different use of memory strategies resulted in different rTMS effects. The SU group showed a selective interference effect after right DLPFC stimulation, whereas the NSU group showed an effect after left DLPFC stimulation. Importantly, the overall performance of the two groups was comparable. We suggest that during memory retrieval the left DLPFC might be recruited when the subject does not apply deliberately a retrieval strategy whereas there is a shift to the right DLPFC if cognitive control processes that are engaged by strategies are needed to guide episodic retrieval., (Copyright (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.)