The objective was to assess dynamic functional connectivity (FC) and local/global connectivity in Parkinson's disease (PD) patients with mild cognitive impairment (PD-MCI) and with normal cognition (PD-NC).The sample included 35 PD patients and 26 healthy controls (HC). Cognitive assessment followed an extensive neuropsychological battery. For resting-state functional MRI (rs-fMRI) analysis, independent component analysis (ICA) was performed and components were located in 7 networks: Subcortical (SC), Auditory (AUD), Somatomotor (SM), visual (VI), cognitive-control (CC), default-mode (DMN), and cerebellar (CB). Dynamic FC analysis was performed using the GIFT toolbox. FC differences between groups in each FC state were analysed with the network-based statistic (NBS) approach. Finally, a graph-theoretical analysis for local/global parameters was performed.The whole sample showed 2 dynamic FC states during the rs-fMRI. PD-MCI patients showed decreased mean dwell time in the hypo-connectivity state (p = 0.030) and showed increased number of state transitions (p = 0.007) compared with the HC. In addition, in the hypo-connectivity state, PD-MCI patients showed reduced inter-network FC between the SM-CC, SM-VI, SM-AUD, CC-VI and SC-DMN compared with the HC (p < 0.05-FDR). These FC alterations in PD-MCI were accompanied by graph-topological alterations in nodes located in the SM network (p < 0.001). In contrast, no differences were found between the PD-NC and HC.Findings suggest the presence of dynamic functional brain deteriorations in PD-MCI that are not present in PD-NC, showing the PD-MCI group dynamic FC dysfunctions, reduced FC mostly between SM-CC networks and graph-topological deteriorations in the SM network. A dynamic FC approach could be helpful to understand cognitive deterioration in PD.

Objectives:To examine the efficacy of an integrative cognitive training program (REHACOP) to improve cognition, clinical symptoms, and functional disability of patients with Parkinson disease (PD).Methods:Forty-two patients diagnosed with PD in Hoehn & Yahr stages 1 to 3 were randomly assigned to either the cognitive training group (REHACOP) or the control group (occupational activities) for 3 months (3 sessions, 60 min/wk). Primary outcomes were change on processing speed, verbal memory, visual memory, executive functioning, and theory of mind. Secondary outcomes included changes on neuropsychiatric symptoms, depression, apathy, and functional disability. The trial was registered with clinicaltrials.gov (NCT02118480).Results:No baseline group differences were found. Bootstrapped analysis of variance results showed significant differences in the mean change scores between the REHACOP group and control group in processing speed (0.13 [SE = 0.07] vs −0.15 [SE = 0.09], p = 0.025), visual memory (0.10 [SE = 0.10] vs −0.24 [SE = 0.09], p = 0.011), theory of mind (1.00 [SE = 0.37] vs −0.27 [SE = 0.29], p = 0.013), and functional disability (−5.15 [SE = 1.35] vs 0.53 [SE = 1.49], p = 0.012).Conclusions:Patients with PD receiving cognitive training with REHACOP demonstrated statistically significant and clinically meaningful changes in processing speed, visual memory, theory of mind, and functional disability. Future studies should consider the long-term effect of this type of intervention. These findings support the integration of cognitive training into the standard of care for patients with PD.Classification of evidence:This study provides Class II evidence that for patients with PD, an integrative cognitive training program improves processing speed, visual memory, theory of mind, and functional disability.

Abstract:Objectives:We hypothesize that time perception and executive functions are interrelated and share neuroanatomical basis, and that fluctuations in levels of cognitive effort play a role in mediating that relation. The main goal of this study was to identify brain structures activated both by increases in cognitive activity and during time perception tasks. Methods:We performed a multimodal meta-analysis to identify common brain regions in the findings of (a) an SDM meta-analysis of neuroimaging studies assessing the brain response to increasing levels of cognitive difficulty, and (b) an ALE meta-analysis on neuroimaging of time perception (Ortuño et al. 2011). Results and conclusions:Consistent with results of previous, separate meta-analyses, the current study supports the hypothesis that there exists a group of brain regions engaged both in time perception tasks and during tasks requiring cognitive effort. Thus, brain regions associated with working memory and executive functions were found to be engaged during time estimation tasks, and regions associated with time perception were found to be engaged by an increase in the difficulty of non-temporal tasks. The implication is that temporal perception and cognitive processes demanding cognitive control become interlinked when there is an increase in the level of cognitive effort demanded.

Cognitive remediation improves cognition in patients with schizophrenia, but its effect on other relevant factors such as negative symptoms and functional outcome has not been extensively studied. In this hospital-based study, 84 inpatients with chronic schizophrenia were recruited from Alava Hospital (Spain). All of the subjects underwent a baseline and a 3-month assessment that examined neurocognition, clinical symptoms, insight, and functional outcome according to the Global Assessment of Functioning (GAF) scale and Disability Assessment Schedule from World Health Organization (DAS-WHO). In addition to receiving standard treatment, patients were randomly assigned either to receive neuropsychological rehabilitation (REHACOP) or to a control group. REHACOP is an integrative program that taps all basic cognitive functions. The program included experts' latest suggestions about positive feedback and activities of daily living in the patients' environment. The REHACOP group showed significantly greater improvements at 3 months in the areas of neurocognition, negative symptoms, disorganization, and emotional distress compared with the control group (Cohen's effect size for these changes ranged from d = 0.47 for emotional distress to d = 0.58 for disorganization symptoms). The REHACOP group also improved significantly in both the GAF (d = 0.61) and DAS-WHO total scores (d = 0.57). Specifically, the patients showed significant improvement in vocational outcomes (d = 0.47), family contact (d = 0.50), and social competence (d = 0.56). In conclusion, neuropsychological rehabilitation may be useful for the reduction of negative symptoms and functional disability in schizophrenia. These findings support the integration of neuropsychological rehabilitation into standard treatment programs for patients with schizophrenia.

By combining different neuroimaging techniques and cognitive data, results showed that functional connectivity alteration between the regions of the DMN is associated with lower cognitive performance and gray and white matter abnormalities in PD.

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Improvement in creativity after transcranial random noise stimulation (tRNs) over the left dorsolateral prefrontal cortexJavier peña , Agurne sampedro, Naroa Ibarretxe-Bilbao, Leire Zubiaurre-elorza & Natalia ojeda Creativity has previously been shown to improve after the application of direct and alternating current transcranial stimulation over the dorsolateral prefrontal cortex (DLpFC). However, previous studies have not tested whether transcranial random noise stimulation (tRNS) was efficient for this purpose. The aim of this randomized, double-blind, placebo-controlled study was to investigate the effect of tRNs on both verbal convergent and (verbal and visual) divergent thinking during left DLpFC tRNs stimulation. thirty healthy participants were randomly allocated to either a tRNs active group or a sham group. Each session lasted 20 min and the current was set to 1.5 mA (100-500 Hz). Participants' verbal convergent thinking was assessed with the Remote Associates test (RAt). Verbal and visual divergent thinking were respectively measured by using the Unusual Uses and picture Completion subtests from the torrance tests of Creative thinking. Bootstrapped analysis of variance showed significant differences in the mean change scores between the active tRNS group and the sham group in RAt scores (d = 1.68); unusual uses: fluency (d = 2.29) and originality (d = 1.43); and general creativity (d = 1.45). Visual divergent thinking, in contrast, did not show any significant improvement. Our results suggested that tRNS over the left DLPFC is effective for increasing verbal divergent and convergent thinking.Creativity plays a key role in many areas of human life, as has been previously suggested 1 . An increasing number of studies have attempted to investigate the neurological basis for creativity using either MRI 2,3 or EEG techniques 4 . Additional evidence of brain areas and networks related to creativity performance has come from studies that included noninvasive transcranial stimulation A review recently carried out by Weinberger et al. 5 indicated that creative cognition may involve two main processes: idea generation (which depends on the availability of unfiltered information), and idea selection (which includes task-directed thoughts and integration of semantically distant concepts). Each of these processes has been suggested to rely primarily on different neural mechanisms 6 .More specifically, idea generation has been mostly related to cathodal Transcranial Direct Current Stimulation (tDCS) of the left inferior frontotemporal cortex, including the anterior temporal lobe 7,8 , inferior frontal gyrus 9 and prefrontal cortex 10 . This improvement in idea generation generally refers to divergent thinking. Divergent thinking has been defined as the ability to simultaneously establish remote associations between unrelated concepts from distant categories, as well as to generate multiple alternative and novel answers to a single problem 11 . For example, Chrysikou et al. 10 reported a higher number of uncommon use...

Memory deficits are common in persons with Parkinson's disease (PD) even without the presence of a frank dementia. These memory deficits have traditionally been attributed to inability of patients to retrieve information from long‐term memory, referred to as the “retrieval failure hypothesis.” However, some studies additionally document problems in recognition memory, noted to be inconsistent with the retrieval failure hypothesis. Given the neuroanatomical abnormalities observed in the hippocampus of PD patients and the role of the hippocampus in learning new information, the current study was designed to specifically examine learning abilities in a nondemented PD sample through the application of a learning paradigm, the Open Trial Selective Reminding Test. We examined 27 patients with PD without dementia and 27 age‐, gender‐, and education‐matched healthy controls (HCs) with a neuropsychological test battery designed to assess new learning and memory. Results indicated a significant difference between the groups in terms of their ability to learn a list of 10 semantically related words. However, once the groups were equated on learning abilities, no significant difference was noted between the PD and HC participants in recall or recognition of the newly learned material. The memory deficit observed in nondemented PD patients is thus largely the result of a deficit in learning new information. This finding should be used to guide treatment for memory deficits in persons with PD, and future research should seek to identify novel means of improving new learning in this population. © 2014 International Parkinson and Movement Disorder Society