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We investigated the activation pattern of the motor cortex (M1) and parietal cortex during immersive virtual reality (VR)-based mirror visual feedback (MVF) of the upper limb in 14 patients with chronic stroke and severe upper limb hemiparesis and in 21 healthy controls. Participants performed wrist extension with unaffected wrists (dominant side in controls). In the MVF condition, movement of the affected hand was synchronized with that of the unaffected hand. In the no-MVF condition, only the movement of unaffected hand was shown. Mu suppression in bilateral M1 and parietal cortex and mu coherence were analyzed. In patients with stroke, MVF induced significant mu suppression in both the ipsilesional M1 and parietal lobes (p = 0.006 and p = 0.009, respectively), while mu suppression was observed in the bilateral M1 (p = 0.003 for ipsilesional and p = 0.041 for contralesional M1, respectively) and contralesional parietal lobes in the controls (p = 0.036). The ipsilesional mu coherence between the M1 and parietal cortex in patients with stroke was stronger than controls, regardless of MVF condition (p < 0.001), while mu coherence between interhemispheric M1 cortices was significantly weaker in patients with stroke (p = 0.032). Our findings provide evidence of the neural mechanism of MVF using immersive VR in patients with stroke. [ABSTRACT FROM AUTHOR]

Background and purpose: Restless legs syndrome (RLS) is a neurological disorder which is most commonly identified by an urge to move the legs. It often shows alterations in sensory processing which implies the salience network (SN) is experiencing changes. This study investigates the functional connectivity (FC) between the SN and other areas of the brain in RLS patients during the resting state period. Methods: Thirty patients with drug naïve idiopathic RLS and 30 healthy age and gender matched controls were included in this study. Resting state fMRIs were performed in the morning during the asymptomatic period. The SN comparisons were conducted between the two groups. Results: The RLS group showed a reduction in SN FC in the right pyramis, and an increase in SN FC in the bilateral orbitofrontal gyri and right postcentral gyrus. Conclusions: The results of this study give reason to believe that SN FC in RLS patients is altered during asymptomatic periods. This could have an influence on the processing of the saliency of information, particularly sensory information processing and inhibition mechanisms. [ABSTRACT FROM AUTHOR]

The action of observing can be used as an effective rehabilitation paradigm, because it activates the mirror neuron system. However, it is difficult to fully use this paradigm because it is difficult to get patients to engage in watching video clips of exercise. In this study, we proposed a steady state visually evoked potential (SSVEP) based paradigm that could be used in a Brain Computer Interface, and examined its feasibility by investigating whether flickering video could activate the mirror neuron system and evoke SSVEPs at the same time. Twenty subjects were recruited and asked to watch the flickering videos at a rate of 20 Hz of upper limb motion and visual white noise, while an EEG signal was recorded. The mu rhythm (8-13 Hz) suppression and the SSVEP (19-21 Hz) evocation were analyzed from recorded EEG. The results showed that SSVEPs, evoked by the flickering stimulus, was observed in both conditions on O1 and O2, but the mu rhythm suppression on C3 and C4 was observed only in the exercise video condition. These results could signify that the flickering video is applicable for the BCI rehabilitation game, activating the mirror neuron system at the same time. [ABSTRACT FROM AUTHOR]

Purpose: Feeling sense of full immersion in computer-generated interactive environments often occurs when the user is enjoying the contents and physiologically and behaviorally responding to the events from that world as if they were real. In this state, the individual may feel embodied in the simulated world even more than in the real world. Although the method of interaction could influence this embodied state during immersive experiencing, the brain mechanism has not yet been investigated. Here we directly investigate brain activities related to an embodied state according to the type of interaction. Methods: Our method uses fMRI scanning during interaction with a virtual avatar using a real-action paradigm and using a simple button as a control task. Results: As the results, we observed the parietal lobe's laterality corresponded to the type of interaction, the left parietal lobe for action task and the right one for the button click condition. In addition, there was a correlation between the motor cortex activities and the co-presence score for realaction condition. The parietal lobe's laterality is related to transformation of self egocentrically or allocentrically from a 1st or 3rd person perspective. Conclusions: Our results provide direct evidence for the involvement of a 1st person perspective embodiment process into a simulated world, particularly into self-avatar, when individual experiences involve a more real-action based interaction method. In contrast, when interacting with simple button-click method, the 3rd person perspective simulation process is recruited for the interaction by controlling the self-avatar rather than experience by oneself with the world. [ABSTRACT FROM AUTHOR]