Search results for "Contralateral hemisphere"

Inter-hemispheric remapping between arm proprioception and vision of the hand is disrupted by single pulse TMS on the left parietal cortex.

2013

International audience; Parietal cortical areas are involved in sensori-motor transformations for their respective contralateral hemifield/body. When arms of the subjects are crossed while their gaze is fixed straight ahead, vision of the hand is processed by the hemisphere ipsilateral to the arm position and proprioception of the arm by the contralateral hemisphere. It induces interhemispheric transfer and remapping. Our objective was to investigate whether a single pulse TMS applied to the left parietal cortical area would disturb interhemispheric remapping in a similar case, and would increase a simple reaction time (RT) with respect to a control single pulse TMS applied to the frontal c…

Experimental „Luxury Perfusion” in the Cerebral Cortex of the Cat

1968

Publisher Summary Preliminary studies have been performed, on the changes of cortical rCBF (Krypton- 85 Beta clearance technique) in response to a localized pressure applied to the cerebral cortex (suprasylvian gyrus) of 8 cats under Nembutal anesthesia (30 to 40 mg/kg bodyweight). No change in rCBF is found at regions as distant as the contralateral hemisphere. The increase of rCBF at the compressed site, during the compression, seems to be more marked in animals with higher blood (i.e. perfusion) pressure, and may be absent in cats with blood pressure of about 80 mm Hg. The augmentation of rCBF around the compressed area during the compression is always very marked, and after some time fl…

2015

The execution of unilateral hand contractions before performance has been reported to produce behavioral aftereffects in various tasks. These effects have been regularly attributed to an induced shift in activation asymmetry to the contralateral hemisphere produced by the contractions. An alternative explanation proposes a generalized state of reduced bilateral cortical activity following unilateral hand contractions. The current experiment contrasted the above explanation models and tested the state of cortical activity after the termination of unilateral hand contractions. Twenty right-handed participants performed hand contractions in two blocks, one for each hand. Using electroencephalo…

Repetitive Transcranial Magnetic Stimulation

2019

Transcranial magnetic stimulation (TMS) represents a valuable neurophysiological technique useful for both research and clinical practice purposes [1]. TMS acts by inducing electrical fields which cause electric currents to flow in targeted cortical areas. These currents interact with the electrical activity of the brain and can depolarize cortical interneurons and/or projection neurons depending on the characteristics of the stimulation. The induced excitation can spread throughout the nervous system by the brain’s normal mechanisms of propagation of neuronal signals. In this way, TMS can also induce functional changes in areas remote to the stimulated cortical area, including both functio…