TY - JOUR A1 - Dordevic, Milos A1 - Hölzer, Sonja A1 - Russo, Augusta A1 - García Alanis, José Carlos A1 - Müller, Notger Germar T1 - The Role of the Precuneus in Human Spatial Updating in a Real Environment Setting—A cTBS Study JF - Life N2 - As we move through an environment, we update positions of our body relative to other objects, even when some objects temporarily or permanently leave our field of view—this ability is termed egocentric spatial updating and plays an important role in everyday life. Still, our knowledge about its representation in the brain is still scarce, with previous studies using virtual movements in virtual environments or patients with brain lesions suggesting that the precuneus might play an important role. However, whether this assumption is also true when healthy humans move in real environments where full body-based cues are available in addition to the visual cues typically used in many VR studies is unclear. Therefore, in this study we investigated the role of the precuneus in egocentric spatial updating in a real environment setting in 20 healthy young participants who underwent two conditions in a cross-over design: (a) stimulation, achieved through applying continuous theta-burst stimulation (cTBS) to inhibit the precuneus and (b) sham condition (activated coil turned upside down). In both conditions, participants had to walk back with blindfolded eyes to objects they had previously memorized while walking with open eyes. Simplified trials (without spatial updating) were used as control condition, to make sure the participants were not affected by factors such as walking blindfolded, vestibular or working memory deficits. A significant interaction was found, with participants performing better in the sham condition compared to real stimulation, showing smaller errors both in distance and angle. The results of our study reveal evidence of an important role of the precuneus in a real-environment egocentric spatial updating; studies on larger samples are necessary to confirm and further investigate this finding. KW - precuneus KW - spatial updating KW - TMS KW - cTBS Y1 - 2022 U6 - https://doi.org/10.3390/life12081239 SN - 2075-1729 VL - 12 SP - 1 EP - 13 PB - MDPI CY - Basel, Schweiz ET - 8 ER - TY - GEN A1 - Dordevic, Milos A1 - Hölzer, Sonja A1 - Russo, Augusta A1 - García Alanis, José Carlos A1 - Müller, Notger Germar T1 - The Role of the Precuneus in Human Spatial Updating in a Real Environment Setting—A cTBS Study T2 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe N2 - As we move through an environment, we update positions of our body relative to other objects, even when some objects temporarily or permanently leave our field of view—this ability is termed egocentric spatial updating and plays an important role in everyday life. Still, our knowledge about its representation in the brain is still scarce, with previous studies using virtual movements in virtual environments or patients with brain lesions suggesting that the precuneus might play an important role. However, whether this assumption is also true when healthy humans move in real environments where full body-based cues are available in addition to the visual cues typically used in many VR studies is unclear. Therefore, in this study we investigated the role of the precuneus in egocentric spatial updating in a real environment setting in 20 healthy young participants who underwent two conditions in a cross-over design: (a) stimulation, achieved through applying continuous theta-burst stimulation (cTBS) to inhibit the precuneus and (b) sham condition (activated coil turned upside down). In both conditions, participants had to walk back with blindfolded eyes to objects they had previously memorized while walking with open eyes. Simplified trials (without spatial updating) were used as control condition, to make sure the participants were not affected by factors such as walking blindfolded, vestibular or working memory deficits. A significant interaction was found, with participants performing better in the sham condition compared to real stimulation, showing smaller errors both in distance and angle. The results of our study reveal evidence of an important role of the precuneus in a real-environment egocentric spatial updating; studies on larger samples are necessary to confirm and further investigate this finding. T3 - Zweitveröffentlichungen der Universität Potsdam : Gesundheitswissenschaftliche Reihe - 1 KW - precuneus KW - spatial updating KW - TMS KW - cTBS Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-565542 SP - 1 EP - 13 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Mehnert, Jan A1 - Brunetti, Maddalena A1 - Steinbrink, Jens A1 - Niedeggen, Michael A1 - Dohle, Christian T1 - Effect of a mirror-like illusion on activation in the precuneus assessed with functional near-infrared spectroscopy JF - Journal of biomedical optics N2 - Mirror therapy is a therapy to treat patients with pain syndromes or hemiparesis after stroke. However, the underlying neurophysiologic mechanisms are not clearly understood. In order to determine the effect of a mirror-like illusion (MIR) on brain activity using functional near-infrared spectroscopy, 20 healthy right-handed subjects were examined. A MIR was induced by a digital horizontal inversion of the subjects' filmed hand. Optodes were placed on the primary motor cortex (M1) and the occipito-parietal cortex (precuneus, PC). Regions of interest (ROI) were defined a priori based on previous results of similar studies and confirmed by the analysis of effect sizes. Analysis of variance of the ROI signal revealed a dissociated pattern: at the PC, the MIR caused a significant inversion of a hemispheric lateralization opposite to the perceived hand, independent of the moving hand. In contrast, activity in M1 showed lateralization opposite to the moving hand, but revealed no mirror effect. These findings extend our understanding on interhemispheric rivalry and indicate that a MIR is integrated into visuomotor coordination similar to normal view, irrespective of the hand that is actually performing the task. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE) KW - functional near-infrared spectroscopy KW - optical imaging KW - mirror illusion KW - mirror therapy KW - precuneus Y1 - 2013 U6 - https://doi.org/10.1117/1.JBO.18.6.066001 SN - 1083-3668 VL - 18 IS - 6 PB - SPIE CY - Bellingham ER - TY - JOUR A1 - Wang, Jing A1 - Fritzsch, Claire A1 - Bernarding, Johannes A1 - Holtze, Susanne A1 - Mauritz, Karl-Heinz A1 - Brunetti, Maddalena A1 - Dohle, Christian T1 - A comparison of neural mechanisms in mirror therapy and movement observation therapy JF - Journal of rehabilitation medicine : official journal of the UEMS European Board of Physical and Rehabilitation Medicine N2 - Objective: To compare lateralized cerebral activations elicited during self-initiated movement mirroring and observation of movements. Subjects: A total of 15 right-handed healthy subjects, age range 22-56 years. Methods: Functional imaging study comparing movement mirroring with movement observation, in both hands, in an otherwise identical setting. Imaging data were analysed using statistical parametric mapping software, with significance threshold set at p<0.01 (false discovery rate) and a minimum cluster size of 20 voxels. Results: Movement mirroring induced additional activation in primary and higher-order visual areas strictly contralateral to the limb seen by the subject. There was no significant difference of brain activity when comparing movement observation of somebody else's right hand with left hand. Conclusion: Lateralized cerebral activations are elicited by inversion of visual feedback (movement mirroring), but not by movement observation. KW - fMRI KW - mirror KW - movement KW - observation KW - precuneus Y1 - 2013 U6 - https://doi.org/10.2340/16501977-1127 SN - 1650-1977 VL - 45 IS - 4 SP - 410 EP - 413 PB - Foundation for Rehabilitation Information CY - Uppsala ER -