906 resultados para Interhemispheric Facilitation


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La sintomatologia ansiosa materna nel periodo prenatale risulta influire negativamente non sullo stato materno ma anche sul successivo sviluppo infantile, Tuttavia, sono limitati gli studi che hanno considerato lo specifico contributo dei disturbi d’ansia nel periodo prenatale. L’obiettivo generale dello studio è quello di indagare nel primo periodo post partum la relazione tra psicopatologia ansiosa materna e: temperamento e sviluppo neonatale, qualità del caregiving materno e dei pattern interattivi madre-bambino. 138 donne sono state intervistate utilizzando SCID-I (First et al., 1997) durante il terzo trimestre di gravidanza. 31 donne (22,5%) presentano disturbo d’ansia nel periodo prenatale. A 1 mese post partum il comportamento del neonato è stato valutato mediante NBAS (Brazelton, Nugent, 1995), mentre le madri hanno compilato MBAS (Brazelton, Nugent, 1995). A 3 mesi postpartum, una sequenza interattiva madre-bambino è stata videoregistrata e codificata utilizzando GRS (Murray et al., 1996). La procedura dello Stranger Episode (Murray et al., 2007) è stata utilizzata per osservare i pattern interattivi materni e infantili nell’interazione con una persona estranea. I neonati di madri con disturbo d’ansia manifestano alle NBAS minori capacità a livello di organizzazione di stati comportamentali, minori capacità attentive e di autoregolazione. Le madri ansiose si percepiscono significativamente meno sicure nell’occuparsi di loro, valutando i propri figli maggiormente instabili e irregolari. Nell’interazione face to face, esse mostrano comportamenti significativamente meno sensibilI, risultando meno coinvolte attivamente con il proprio bambino. Durante lo Stranger Episode, le madri con fobia sociale presentano maggiori livelli di ansia e incoraggiando in modo significativamente inferiore l’interazione del bambino con l’estraneo. I risultati sottolineano l’importanza di valutare in epoca prenatale la psicopatologia ansiosa materna. Le evidenze confermano la rilevanza che può assumere un modello multifattoriale di rischio in cui i disturbi d’ansia prenatali e la qualità del caregiving materno possono agire in modo sinergico nell’influire sugli esiti infantili.

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It has been shown in the study that glutamate transporters (EAAT) are capable to modulate GABA transports (GAT). Here we also report that DL-TBOA, a non-transportable glutamate uptake blocker, eliminates GAT-mediated GABA release, while D-aspartate, an EAAT substrate, does not block the latter. The strength or even the operating mode of GABA uptake/release could be influenced by the work of EAATs. Considering the interaction between EAATs and GATs we can conclude that ambient glutamate and GABA levels are mutually dependent. The EAAT-GAT crosstalk observed in this work is mediated by EAAT1 and GAT-2/3. Since both transporters are Na+ dependent and mainly glial, next we investigated the role of [Na+]i in astrocytic-mediated glutamate uptake. We tested whether [Na+]i changes affect paired-pulse plasticity of STCs recorded from cortical layer 2/3 astrocytes. We report that an elevation of [Na+]i induced either by using a high [Na+]i intrapipette solution or by application of GABA slows STCs kinetics and decrease paired-pulse facilitation (PPF) of STCs at short inter-stimulus intervals. Moreover, GAT inhibitors decrease PPF of STCs under control conditions, suggesting that endogenous GABA operating via GATs influences EAAT-mediated transport

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Hemispatial neglect - defined as the failure to attend, explore, and act upon the contralesional side of space - is a frequent and disabling neurological syndrome. Interhemispheric rivalry is considered as a major pathophysiological mechanism underlying hemispatial neglect. According to this account, the contralesional, intact hemisphere undergoes a pathological hyperactivity due to a deficient transcallosal inhibition from the damaged hemisphere. This model offers a framework for possible therapeutic interventions with repetitive transcranial magnetic stimulation (rTMS), i.e. a reduction of the pathological hyperactivity with a rTMS protocol that has lasting inhibitory effects. In the present work, we will first review evidence for the interhemispheric rivalry account coming from animals and humans. We will then describe studies showing the possibility to perturb and to restore interhemispheric balance in healthy subjects as a proof of concept for therapeutic rTMS application. Finally, we will consider studies applying rTMS as a therapeutic approach in hemispatial neglect. We conclude that rTMS is a promising approach to reduce the interhemispheric imbalance in neglect patients and to ameliorate symptoms. Newly developed protocols such as Theta Burst Stimulation (TBS) - with short stimulation times and long offline effects - seem to be particularly convenient. However, future studies should assess stimulation effects not only in clinical testing, but also on disability, considering combination with traditional therapies as well.

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National studies indicate that approximately 25 percent of women have been sexually assaulted by the time they finish college. Although male peers are often the perpetrators, women also engage in behaviors with their female peers that may increase the risk of sexualassault. In the present study, we sought to determine how often college women engaged in these behaviors (i.e. “female facilitation”). Participants were 373 female students (sophomorethrough senior; Greek and independent) who completed an online survey containing measures of sexual assault, alcohol consumption, and female facilitation. The female facilitation measure indexed both “facilitator” behaviors (those directed toward others thatlikely increase the risk of sexual assault victimization) and “facilitatee” behaviors (those that may increase risk of sexual assault victimization), and the two sets of items werecounterbalanced across participants. Descriptive statistics showed an overall prevalence rate for any type of sexual assault was 44.2%. Scores on the facilitator and facilitatee versions ofthe female facilitation measure were highly correlated. Facilitation was highly correlated with alcohol consumption, and being a faciltatee was moderately correlated with sexual assault. Results were consistent with some of our expectations regarding the relationships among facilitation, alcohol consumption, sexual assault, and demographic variables. Limitations of the methods and the implications of the findings for understanding campussexual assault will be discussed.

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In binocular rivalry, presentation of different images to the separate eyes leads to conscious perception alternating between the two possible interpretations every few seconds. During perceptual transitions, a stimulus emerging into dominance can spread in a wave-like manner across the visual field. These traveling waves of rivalry dominance have been successfully related to the cortical magnification properties and functional activity of early visual areas, including the primary visual cortex (V1). Curiously however, these traveling waves undergo a delay when passing from one hemifield to another. In the current study, we used diffusion tensor imaging (DTI) to investigate whether the strength of interhemispheric connections between the left and right visual cortex might be related to the delay of traveling waves across hemifields. We measured the delay in traveling wave times (ΔTWT) in 19 participants and repeated this test 6 weeks later to evaluate the reliability of our behavioral measures. We found large interindividual variability but also good test-retest reliability for individual measures of ΔTWT. Using DTI in connection with fiber tractography, we identified parts of the corpus callosum connecting functionally defined visual areas V1-V3. We found that individual differences in ΔTWT was reliably predicted by the diffusion properties of transcallosal fibers connecting left and right V1, but observed no such effect for neighboring transcallosal visual fibers connecting V2 and V3. Our results demonstrate that the anatomical characteristics of topographically specific transcallosal connections predict the individual delay of interhemispheric traveling waves, providing further evidence that V1 is an important site for neural processes underlying binocular rivalry.

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Left-sided spatial neglect is a common neurological syndrome following right-hemispheric stroke. The presence of spatial neglect is a powerful predictor of poor rehabilitation outcome. In one influential account of spatial neglect, interhemispheric inhibition is impaired and leads to a pathological hyperactivity in the contralesional hemisphere, resulting in a biased attentional allocation towards the right hemifield. Inhibitory transcranial magnetic stimulation can reduce the hyperactivity of the contralesional, intact hemisphere and thereby improve spatial neglect symptoms. However, it is not known whether this improvement is also relevant to the activities of daily living during spontaneous behaviour. The primary aim of the present study was to investigate whether the repeated application of continuous theta burst stimulation trains could ameliorate spatial neglect on a quantitative measure of the activities of daily living during spontaneous behaviour. We applied the Catherine Bergego Scale, a standardized observation questionnaire that can validly and reliably detect the presence and severity of spatial neglect during the activities of daily living. Eight trains of continuous theta burst stimulation were applied over two consecutive days on the contralesional, left posterior parietal cortex in patients suffering from subacute left spatial neglect, in a randomized, double-blind, sham-controlled design, which also included a control group of neglect patients without stimulation. The results showed a 37% improvement in the spontaneous everyday behaviour of the neglect patients after the repeated application of continuous theta burst stimulation. Remarkably, the improvement persisted for at least 3 weeks after stimulation. The amelioration of spatial neglect symptoms in the activities of daily living was also generally accompanied by significantly better performance in the neuropsychological tests. No significant amelioration in symptoms was observed after sham stimulation or in the control group without stimulation. These results provide Class I evidence that continuous theta burst stimulation is a viable add-on therapy in neglect rehabilitation that facilitates recovery of normal everyday behaviour.

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Psychological flow describes the mental phenomenon that takes place during intense engagement with a task (Jackson & Csikszentmihalyi, 1999). Its components have been operationalized through the development of the Flow State Scale (Jackson & Eklund, 2002). As feedback has been shown to be a critical element for the facilitation of a flow experience (Moneta, 2012), the current study sought to investigate the effect of differential feedback on psychological flow outcomes using the FSS as the dependent variable. The feedback manipulation featured three experimental groups; control, positive, and negative. This study also accounted for the personality trait of perfectionism as a variable influencing the experience of flow. Following the completion of a personality measure, participants engaged in a bolt threading task for ten minutes, then reported the time they perceived to have spent on the task as well as the outcome of their flow experience. The feedback conditions were created by the use of different size containers for participants to place their nut and bolt pairs in, and thus feedback was inherent in the task. The study found that feedback played an important role in the outcome of a flow experience. The positive feedback condition was more conducive to flow than the negative feedback condition. Furthermore, those in the positive condition outperformed those in the negative condition during the ten minutes. Goal clarity and feedback clarity differed significantly across feedback manipulations. Perfectionism¿s impact on the outcome of flow was more pronounced in the negative feedback condition than the positive or control conditions. In settings where engagement and performance are imperative, ample attention should be given to the feedback processes present in the situation.

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OBJECTIVES: Aim of this study was to compare the utility of susceptibility weighted imaging (SWI) with the established diagnostic techniques CT and fluid attenuated inversion recovery (FLAIR) in their detecting capacity of subarachnoid hemorrhage (SAH), and further to compare the combined SWI/FLAIR MRI data with CT to evaluate whether MRI is more accurate than CT. METHODS: Twenty-five patients with acute SAH underwent CT and MRI within 6 days after symptom onset. Underlying pathology for SAH was head trauma (n=9), ruptured aneurysm (n=6), ruptured arteriovenous malformation (n=2), and spontaneous bleeding (n=8). SWI, FLAIR, and CT data were analyzed. The anatomical distribution of SAH was subdivided into 8 subarachnoid regions with three peripheral cisterns (frontal-parietal, temporal-occipital, sylvian), two central cisterns and spaces (interhemispheric, intraventricular), and the perimesencephalic, posterior fossa, superior cerebellar cisterns. RESULTS: SAH was detected in a total of 146 subarachnoid regions. CT identified 110 (75.3%), FLAIR 127 (87%), and SWI 129 (88.4%) involved regions. Combined FLAIR and SWI identified all 146 detectable regions (100%). FLAIR was sensitive for frontal-parietal, temporal-occipital and Sylvian cistern SAH, while SWI was particularly sensitive for interhemispheric and intraventricular hemorrhage. CONCLUSIONS: By combining SWI and FLAIR, MRI yields a distinctly higher detection rate for SAH than CT alone, particularly due to their complementary detection characteristics in different anatomical regions. Detection strength of SWI is high in central areas, whereas FLAIR shows a better detection rate in peripheral areas.

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PURPOSE : For the facilitation of minimally invasive robotically performed direct cochlea access (DCA) procedure, a surgical planning tool which enables the surgeon to define landmarks for patient-to-image registration, identify the necessary anatomical structures and define a safe DCA trajectory using patient image data (typically computed tomography (CT) or cone beam CT) is required. To this end, a dedicated end-to-end software planning system for the planning of DCA procedures that addresses current deficiencies has been developed. METHODS :    Efficient and robust anatomical segmentation is achieved through the implementation of semiautomatic algorithms; high-accuracy patient-to-image registration is achieved via an automated model-based fiducial detection algorithm and functionality for the interactive definition of a safe drilling trajectory based on case-specific drill positioning uncertainty calculations was developed. RESULTS :    The accuracy and safety of the presented software tool were validated during the conduction of eight DCA procedures performed on cadaver heads. The plan for each ear was completed in less than 20 min, and no damage to vital structures occurred during the procedures. The integrated fiducial detection functionality enabled final positioning accuracies of [Formula: see text] mm. CONCLUSIONS :    Results of this study demonstrated that the proposed software system could aid in the safe planning of a DCA tunnel within an acceptable time.

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Until relatively recently, most psychologists have had limited professional involvement with older adults. With the baby boomers starting to turn 65 years old in 2011, sheer numbers of older adults will continue to increase. About 1 in 5 older adults has a mental disorder, such as dementia. Their needs for mental and behavioral health services are not now adequately met, and the decade ahead will require an approximate doubling of the current level of psychologists' time with older adults. Public policy in the coming decade will face tensions between cost containment and facilitation of integrated models of care. Most older adults who access mental health services do so in primary care settings, where interdisciplinary, collaborative models of care have been found to be quite effective. To meet the needs of the aging population, psychologists need to increase awareness of competencies for geropsychology practice and knowledge regarding dementia diagnosis, screening, and services. Opportunities for psychological practice are anticipated to grow in primary care, dementia and family caregiving services, decision-making-capacity evaluation, and end-of-life care. Aging is an aspect of diversity that can be integrated into psychology education across levels of training. Policy advocacy for geropsychology clinical services, education, and research remains critical. Psychologists have much to offer an aging society

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Neural dynamic processes correlated over several time scales are found in vivo, in stimulus-evoked as well as spontaneous activity, and are thought to affect the way sensory stimulation is processed. Despite their potential computational consequences, a systematic description of the presence of multiple time scales in single cortical neurons is lacking. In this study, we injected fast spiking and pyramidal (PYR) neurons in vitro with long-lasting episodes of step-like and noisy, in-vivo-like current. Several processes shaped the time course of the instantaneous spike frequency, which could be reduced to a small number (1-4) of phenomenological mechanisms, either reducing (adapting) or increasing (facilitating) the neuron's firing rate over time. The different adaptation/facilitation processes cover a wide range of time scales, ranging from initial adaptation (<10 ms, PYR neurons only), to fast adaptation (<300 ms), early facilitation (0.5-1 s, PYR only), and slow (or late) adaptation (order of seconds). These processes are characterized by broad distributions of their magnitudes and time constants across cells, showing that multiple time scales are at play in cortical neurons, even in response to stationary stimuli and in the presence of input fluctuations. These processes might be part of a cascade of processes responsible for the power-law behavior of adaptation observed in several preparations, and may have far-reaching computational consequences that have been recently described.

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The role of gap junction channels on cardiac impulse propagation is complex. This review focuses on the differential expression of connexins in the heart and the biophysical properties of gap junction channels under normal and disease conditions. Structural determinants of impulse propagation have been gained from biochemical and immunocytochemical studies performed on tissue extracts and intact cardiac tissue. These have defined the distinctive connexin coexpression patterns and relative levels in different cardiac tissues. Functional determinants of impulse propagation have emerged from electrophysiological experiments carried out on cell pairs. The static properties (channel number and conductance) limit the current flow between adjacent cardiomyocytes and thus set the basic conduction velocity. The dynamic properties (voltage-sensitive gating and kinetics of channels) are responsible for a modulation of the conduction velocity during propagated action potentials. The effect is moderate and depends on the type of Cx and channel. For homomeric-homotypic channels, the influence is small to medium; for homomeric-heterotypic channels, it is medium to strong. Since no data are currently available on heteromeric channels, their influence on impulse propagation is speculative. The modulation by gap junction channels is most prominent in tissues at the boundaries between cardiac tissues such as sinoatrial node-atrial muscle, atrioventricular node-His bundle, His bundle-bundle branch and Purkinje fibers-ventricular muscle. The data predict facilitation of orthodromic propagation.

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It is widely accepted that peripheral trauma such as soft tissue injuries can trigger dystonia, although little is known about the underlying mechanism. Because peripheral injury only rarely appears to elicit dystonia, a predisposing vulnerability in cortical motor areas might play a role. Using single and paired-pulse pulse transcranial magnetic stimulation, we evaluated motor cortex excitability of a hand muscle in a patient with peripherally induced foot dystonia, in her brother with craniocervical dystonia, and in her unaffected sister, and compared their results to those from a group of normal subjects. In the patient with peripherally induced dystonia, we found a paradoxical intracortical facilitation at short interstimulus intervals of 3 and 5 milliseconds, at which regular intracortical inhibition (ICI) occurred in healthy subjects. These findings suggest that the foot dystonia may have been precipitated as the result of a preexisting abnormality of motor cortex excitability. Furthermore, the abnormality of ICI in her brother and sister indicates that altered motor excitability may be a hereditary predisposition. The study demonstrates that the paired-pulse technique is a useful tool to assess individual vulnerability, which can be particularly relevant when the causal association between trauma and dystonia is less evident.

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Ca(v)2.1 Ca(2+) channels (P/Q-type), which participate in various key roles in the CNS by mediating calcium influx, are extensively spliced. One of its alternatively-spliced exons is 37, which forms part of the EF hand. The expression of exon 37a (EFa form), but not exon 37b (EFb form), confers the channel an activity-dependent enhancement of channel opening known as Ca(2+)-dependent facilitation (CDF). In this study, we analyzed the trend of EF hand splice variant distributions in mouse, rat and human brain tissues. We observed a developmental switch in rodents, as well as an age and gender bias in human brain tissues, suggestive of a possible role of these EF hand splice variants in neurophysiological specialization. A parallel study performed on rodent brains showed that the data drawn from human and rodent tissues may not necessarily correlate in the process of aging.

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The aim of this study was to investigate the effect of single-pulse transcranial magnetic stimulation on the triggering of saccades. The right frontal eye field was stimulated during modified gap and overlap paradigms with flashed presentation of the lateral visual target of 80 ms. In order to examine possible facilitating or inhibitory effects on saccade triggering, three different time intervals of stimulation were chosen, i.e. simultaneously with onset of the target, during the presentation and after target end. Stimulation applied simultaneously with target onset significantly decreased the latency of contralateral saccades in the gap but not in the overlap paradigm. Stimulation after target end significantly increased saccade latency for both sides in the gap paradigm and for the contralateral side in the overlap paradigm. Stimulation during presentation had no effect in either paradigm. The results show that, depending on the time interval and the paradigm tested, a facilitation or inhibition of saccade triggering can be achieved. The results are discussed in a context of two probable transcranial magnetic stimulation effects, a direct interference with the frontal eye field on the one hand and a remote interference with the superior colliculus on the other hand.