This file was created by the Typo3 extension sevenpack version 0.7.14 --- Timezone: CEST Creation date: 2013-05-21 Creation time: 15-51-12 --- Number of references 2 article BorchersHLK2012 Nature Reviews Neuroscience 2012 1 13 1 63-70 Despite its clinical relevance, direct electrical stimulation (DES) of the human brain is surprisingly poorly understood. Although we understand several aspects of electrical stimulation at the cellular level, surface DES evokes a complex summation effect in a large volume of brain tissue, and the effect is difficult to predict as it depends on many local and remote physiological and morphological factors. The complex stimulation effects are reflected in the heterogeneity of behavioural effects that are induced by DES, which range from evocation to inhibition of responses — sometimes even when DES is applied at the same cortical site. Thus, it is a misconception that DES — in contrast to other neuroscience techniques — allows us to draw unequivocal conclusions about the role of stimulated brain areas. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Logothetis http://www.nature.com/nrn/journal/v13/n1/pdf/nrn3140.pdf 10.1038/nrn3140 svenjaSBorchers MHimmelbach nikosNKLogothetis HOKarnath conference 7080 2010 10 11 7 Sensory representations of arm and hand in the postcentral gyrus are usually supposed to be strictly lateralized and to allow a spatially unbiased representation of the position of the contralateral limb in egocentric space. Here we report a patient whose behavior suggests a different organization of proprioceptive representations. Patient R.W. demonstrated an isolated proprioceptive deficit without hemiparesis due to a lesion of the right postcentral gyrus. We examined her limb position sense in a finger position matching task. Target locations were defined by passively positioning the index finger of one hand beneath a table surface. With the other hand above the table R.W. indicated the perceived position of the finger below the table. Without visual feedback of either hand, we observed a significant leftward shift of perceived locations when reaching with the right hand and an opposite rightward shift when reaching with the left hand in comparison to age-matched healthy controls. These directional errors improved when vision of the active hand was allowed. However, position errors were still significantly different from the control group even with free view of the contralesional hand. Pointing to visual targets without feedback of the moving hand, R.W. revealed errors with both hands that were significantly different from the performance of healthy controls. However, pointing to visual targets with full visual feedback, R.W. was as accurate as controls with either hand. Thus we can exclude a contribution of subclinical visual or motor deficits to the observed impairments. In summary, our data show a contralesional shift of the perceived position of the contralesional hand suggesting a directional bias of proprioceptive representations. Furthermore, our data reveals an effect of the right hemisphere lesion on proprioceptive information processing for the ipsilateral hand. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department MRZ Abstract Talk http://www.neuroschool-tuebingen-nena.de/fileadmin/user_upload/Dokumente/neuroscience/AbstractbookNeNa2010u.pdf Biologische Kybernetik Max-Planck-Gesellschaft Heiligkreuztal, Germany 11th Conference of Junior Neuroscientists of Tübingen (NeNa 2010) en svenjaSBorchers