The Experts below are selected from a list of 21756 Experts worldwide ranked by ideXlab platform

Klaus L Leenders - One of the best experts on this subject based on the ideXlab platform.

  • changes in cerebral activations during movement Execution and imagery after parietal cortex tms interleaved with 3t mri
    2009
    Co-Authors: Paulien M De Vries, Bauke M De Jong, Daryl E Bohning, John Walker, Mark S George, Klaus L Leenders
    Abstract:

    The left parietal cortex contributes to goal-directed hand movement. In this study, we targeted this region with transcranial magnetic stimulation (TMS) to assess the effects on a wider distributed circuitry related to motor control. Ten healthy subjects underwent 3 Tesla functional magnetic resonance imaging (fMRI) with interleaved TMS. They either executed or imagined right wrist flexion/extension movements, which was preceded by a 10-second period either with or without TMS. This was applied to the left superior parietal cortex in 10 stimuli of 1 Hz at 115% motor threshold intensity. TMS preceding the movement Execution Condition resulted in significantly increased activation in the bilateral prefrontal, right temporo-parietal and left posterior parietal cortices, when compared to movement without such intervention (P<0.001 voxel-level; P<0.05, volume corrected). Movement imagery after TMS showed significantly increased activation in the left medial prefrontal cortex, right lateral prefrontal cortex, left supramarginal gyrus and right occipital cortex, while a decrease was present in bilateral anterior parietal cortex (P<0.01 voxel-level; P<0.05 volume corrected). Activation changes after TMS of left superior parietal cortex thus appears to increase prefrontal and posterior parietal cortex activation, associated with a reduced function of the anterior parietal cortex, including S2. These changes are thought to reflect an impaired ability to estimate the proprioceptive consequences of movement during its preparation, which is compensated by the increased contribution of more remote parietal and prefrontal cortical regions.

Tibor Auer - One of the best experts on this subject based on the ideXlab platform.

  • brain networks underlying strategy Execution and feedback processing in an efficient functional magnetic resonance imaging neurofeedback training performed in a parallel or a serial paradigm
    2021
    Co-Authors: Wan Ilma Dewiputri, Renate Schweizer, Tibor Auer
    Abstract:

    Neurofeedback (NF) is a complex learning scenario, as the task consists of trying out mental strategies while processing a feedback signal that signifies activation in the brain area to be self-regulated and acts as a potential reward signal. In an attempt to dissect these subcomponents, we obtained whole-brain networks associated with efficient self-regulation in two paradigms: parallel, where the task was performed concurrently, combining feedback with strategy Execution; and serial, where the task was performed consecutively, separating feedback processing from strategy Execution. Twenty participants attempted to control their anterior midcingulate cortex (aMCC) using functional magnetic resonance imaging (fMRI) NF in 18 sessions over 2 weeks, using cognitive and emotional mental strategies. We analyzed whole-brain fMRI activations in the NF training runs with the largest aMCC activation for the serial and parallel paradigms. The equal length of the strategy Execution and the feedback processing periods in the serial paradigm allows a description of the two task subcomponents with equal power. The resulting activation maps were spatially correlated with functionally annotated intrinsic connectivity brain maps (BMs). Brain activation in the parallel Condition correlates with the basal ganglia (BG) network, the cingulo-opercular network (CON), and the frontoparietal control network (FPCN); brain activation in the serial strategy Execution Condition with the default mode network (DMN), the FPCN, and the visual processing network; while brain activation in the serial feedback processing Condition predominantly with the CON, the DMN, and the FPCN. Additional comparisons indicate that BG activation is characteristic to the parallel paradigm, while supramarginal gyrus (SMG) and superior temporal gyrus (STG) activations are characteristic to the serial paradigm. The multifaceted view of the subcomponents allows describing the cognitive processes associated with strategy Execution and feedback processing independently in the serial feedback task and as combined processes in the multitasking scenario of the conventional parallel feedback task.

Wan Ilma Dewiputri - One of the best experts on this subject based on the ideXlab platform.

  • brain networks underlying strategy Execution and feedback processing in an efficient functional magnetic resonance imaging neurofeedback training performed in a parallel or a serial paradigm
    2021
    Co-Authors: Wan Ilma Dewiputri, Renate Schweizer, Tibor Auer
    Abstract:

    Neurofeedback (NF) is a complex learning scenario, as the task consists of trying out mental strategies while processing a feedback signal that signifies activation in the brain area to be self-regulated and acts as a potential reward signal. In an attempt to dissect these subcomponents, we obtained whole-brain networks associated with efficient self-regulation in two paradigms: parallel, where the task was performed concurrently, combining feedback with strategy Execution; and serial, where the task was performed consecutively, separating feedback processing from strategy Execution. Twenty participants attempted to control their anterior midcingulate cortex (aMCC) using functional magnetic resonance imaging (fMRI) NF in 18 sessions over 2 weeks, using cognitive and emotional mental strategies. We analyzed whole-brain fMRI activations in the NF training runs with the largest aMCC activation for the serial and parallel paradigms. The equal length of the strategy Execution and the feedback processing periods in the serial paradigm allows a description of the two task subcomponents with equal power. The resulting activation maps were spatially correlated with functionally annotated intrinsic connectivity brain maps (BMs). Brain activation in the parallel Condition correlates with the basal ganglia (BG) network, the cingulo-opercular network (CON), and the frontoparietal control network (FPCN); brain activation in the serial strategy Execution Condition with the default mode network (DMN), the FPCN, and the visual processing network; while brain activation in the serial feedback processing Condition predominantly with the CON, the DMN, and the FPCN. Additional comparisons indicate that BG activation is characteristic to the parallel paradigm, while supramarginal gyrus (SMG) and superior temporal gyrus (STG) activations are characteristic to the serial paradigm. The multifaceted view of the subcomponents allows describing the cognitive processes associated with strategy Execution and feedback processing independently in the serial feedback task and as combined processes in the multitasking scenario of the conventional parallel feedback task.

Bauke M De Jong - One of the best experts on this subject based on the ideXlab platform.

  • changes in cerebral activations during movement Execution and imagery after parietal cortex tms interleaved with 3t mri
    2009
    Co-Authors: Paulien M De Vries, Bauke M De Jong, Daryl E Bohning, John Walker, Mark S George, Klaus L Leenders
    Abstract:

    The left parietal cortex contributes to goal-directed hand movement. In this study, we targeted this region with transcranial magnetic stimulation (TMS) to assess the effects on a wider distributed circuitry related to motor control. Ten healthy subjects underwent 3 Tesla functional magnetic resonance imaging (fMRI) with interleaved TMS. They either executed or imagined right wrist flexion/extension movements, which was preceded by a 10-second period either with or without TMS. This was applied to the left superior parietal cortex in 10 stimuli of 1 Hz at 115% motor threshold intensity. TMS preceding the movement Execution Condition resulted in significantly increased activation in the bilateral prefrontal, right temporo-parietal and left posterior parietal cortices, when compared to movement without such intervention (P<0.001 voxel-level; P<0.05, volume corrected). Movement imagery after TMS showed significantly increased activation in the left medial prefrontal cortex, right lateral prefrontal cortex, left supramarginal gyrus and right occipital cortex, while a decrease was present in bilateral anterior parietal cortex (P<0.01 voxel-level; P<0.05 volume corrected). Activation changes after TMS of left superior parietal cortex thus appears to increase prefrontal and posterior parietal cortex activation, associated with a reduced function of the anterior parietal cortex, including S2. These changes are thought to reflect an impaired ability to estimate the proprioceptive consequences of movement during its preparation, which is compensated by the increased contribution of more remote parietal and prefrontal cortical regions.

Krish Devi Singh - One of the best experts on this subject based on the ideXlab platform.

  • modulation of the human mirror neuron system during cognitive activity
    2008
    Co-Authors: Suresh Daniel Muthukumaraswamy, Krish Devi Singh
    Abstract:

    In this experiment we examined the relationship between the mirror neuron system and increased attention caused by task demands. Whole head MEG recordings were made from 13 participants who were asked to passively observe finger movement sequences, observe these sequences with the knowledge they would later have to perform the sequence presented, and finally, to perform a nonmotor mathematics task based on the finger-movement sequences. Beta-band (15–35 Hz) sensorimotor desynchronization was found in overlapping areas during passive observation and in a separate motor Execution Condition, indicating the activity of the human mirror neuron system. The beta desynchronization in these areas was enhanced relative to passive viewing when participants had to watch the stimuli to later imitate and when they performed the mathematics task, indicating that mirror neuron system activity can be modulated by attention.