scholarly journals Reversible Deactivation of Motor Cortex Reveals Functional Connectivity with Posterior Parietal Cortex in the Prosimian Galago (Otolemur garnettii)

2015 ◽  
Vol 35 (42) ◽  
pp. 14406-14422 ◽  
Author(s):  
D. F. Cooke ◽  
I. Stepniewska ◽  
D. J. Miller ◽  
J. H. Kaas ◽  
L. Krubitzer
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Otolemur Garnettii ◽  
Reversible Deactivation ◽  
Posterior Parietal

scholarly journals Functional Connectivity at Rest between the Human Medial Posterior Parietal Cortex and the Primary Motor Cortex Detected by Paired-Pulse Transcranial Magnetic Stimulation

2021 ◽  
Vol 11 (10) ◽  
pp. 1357
Author(s):  
Rossella Breveglieri ◽  
Sara Borgomaneri ◽  
Matteo Filippini ◽  
Marina De Vitis ◽  
Alessia Tessari ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Functional Connectivity ◽  
Motor Cortex ◽  
Parietal Cortex ◽  
Magnetic Stimulation ◽  
Posterior Parietal Cortex ◽  
Primary Motor Cortex ◽  
Conditioning Stimulus ◽  
Visuomotor Integration ◽  
Posterior Parietal

The medial posterior parietal cortex (PPC) is involved in the complex processes of visuomotor integration. Its connections to the dorsal premotor cortex, which in turn is connected to the primary motor cortex (M1), complete the fronto-parietal network that supports important cognitive functions in the planning and execution of goal-oriented movements. In this study, we wanted to investigate the time-course of the functional connectivity at rest between the medial PPC and the M1 using dual-site transcranial magnetic stimulation in healthy humans. We stimulated the left M1 using a suprathreshold test stimulus to elicit motor-evoked potentials in the hand, and a subthreshold conditioning stimulus was applied over the left medial PPC at different inter-stimulus intervals (ISIs). The conditioning stimulus affected the M1 excitability depending on the ISI, with inhibition at longer ISIs (12 and 15 ms). We suggest that these modulations may reflect the activation of different parieto-frontal pathways, with long latency inhibitions likely recruiting polisynaptic pathways, presumably through anterolateral PPC.

Measurements of evoked electroencephalograph by transcranial magnetic stimulation applied to motor cortex and posterior parietal cortex

2009 ◽  
Vol 105 (7) ◽  
pp. 07B321 ◽  
Author(s):  
Masakuni Iwahashi ◽  
Yohei Koyama ◽  
Akira Hyodo ◽  
Takehito Hayami ◽  
Shoogo Ueno ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Parietal Cortex ◽  
Magnetic Stimulation ◽  
Posterior Parietal Cortex ◽  
Posterior Parietal

scholarly journals Simultaneous Preparation of Multiple Potential Movements: Opposing Effects of Spatial Proximity Mediated by Premotor and Parietal Cortex

2009 ◽  
Vol 102 (4) ◽  
pp. 2084-2095 ◽  
Author(s):  
Peter Praamstra ◽  
Dimitrios Kourtis ◽  
Kianoush Nazarpour
Keyword(s):  
Motor Cortex ◽  
Distributed Control ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Delay Period ◽  
Spatial Proximity ◽  
Frontoparietal Network ◽  
Neurophysiological Studies ◽  
Preparatory Activity ◽  
Posterior Parietal

Neurophysiological studies in monkey have suggested that premotor and motor cortex may prepare for multiple movements simultaneously, sustained by cooperative and competitive interactions within and between the neural populations encoding different actions. Here, we investigate whether competition between alternative movement directions, manipulated in terms of number and spatial angle, is reflected in electroencephalographic (EEG) measures of (pre)motor cortical activity in humans. EEG was recorded during performance of a center-out pointing task in which response signals were preceded by cues providing prior information in the form of arrows pointing to one or more possible movement targets. Delay-period activity in (pre)motor cortex was modulated in the predicted manner by the number of possible movement directions and by the angle separating them. Response latencies, however, were determined not only by the amplitude of movement-preparatory activity, but also by differences in the duration of stimulus evaluation against the visuospatial memory of the cue, reflected in EEG potentials originating from posterior parietal cortex (PPC). Specifically, the spatial proximity of possible movement targets was processed differently by (pre)motor and posterior parietal cortex. Spatial proximity enhanced the amplitude of (pre)motor cortex preparatory activity during the delay period but delayed evaluation of the response signal in the PPC, thus producing opposite effects on response latency. The latter finding supports distributed control of movement decisions in the frontoparietal network, revealing a feature of distributed control that is of potential significance for the understanding of distracter effects in reaching and pointing.

scholarly journals Rubber hand illusion modulates the influences of somatosensory and parietal inputs to the motor cortex

2019 ◽  
Vol 121 (2) ◽  
pp. 563-573 ◽  
Author(s):  
Reina Isayama ◽  
Michael Vesia ◽  
Gaayathiri Jegatheeswaran ◽  
Behzad Elahi ◽  
Carolyn A. Gunraj ◽  
...  
Keyword(s):  
Motor Control ◽  
Motor Cortex ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Rubber Hand Illusion ◽  
Body Ownership ◽  
Rubber Hand ◽  
Functional Connections ◽  
Afferent Inhibition ◽  
Posterior Parietal

The rubber hand illusion (RHI) paradigm experimentally produces an illusion of rubber hand ownership and arm shift by simultaneously stroking a rubber hand in view and a participant’s visually occluded hand. It involves visual, tactile, and proprioceptive multisensory integration and activates multisensory areas in the brain, including the posterior parietal cortex (PPC). Multisensory inputs are transformed into outputs for motor control in association areas such as PPC. A behavioral study reported decreased motor performance after RHI. However, it remains unclear whether RHI modifies the interactions between sensory and motor systems and between PPC and the primary motor cortex (M1). We used transcranial magnetic stimulation (TMS) and examined the functional connections from the primary somatosensory and association cortices to M1 and from PPC to M1 during RHI. In experiment 1, short-latency afferent inhibition (SAI) and long-latency afferent inhibition (LAI) were measured before and immediately after a synchronous (RHI) or an asynchronous (control) condition. In experiment 2, PPC-M1 interaction was measured using two coils. We found that SAI and LAI were reduced in the synchronous condition compared with baseline, suggesting that RHI decreased somatosensory processing in the primary sensory and the association cortices projecting to M1. We also found that greater inhibitory PPC-M1 interaction was associated with stronger RHI assessed by questionnaire. Our findings suggest that RHI modulates both the early and late stages of processing of tactile afferent, which leads to altered M1 excitability by reducing the gain of somatosensory afferents to resolve conflicts among multisensory inputs. NEW & NOTEWORTHY Perception of one’s own body parts involves integrating different sensory information and is important for motor control. We found decreased effects of cutaneous stimulation on motor cortical excitability during rubber hand illusion (RHI), which may reflect decreased gain of tactile input to resolve multisensory conflicts. RHI strength correlated with the degree of inhibitory posterior parietal cortex-motor cortex interaction, indicating that parietal-motor connection is involved in resolving sensory conflicts and body ownership during RHI.

scholarly journals Timing-dependent modulation of the posterior parietal cortex–primary motor cortex pathway by sensorimotor training

2012 ◽  
Vol 107 (11) ◽  
pp. 3190-3199 ◽  
Author(s):  
Anke Karabanov ◽  
Seung-Hyun Jin ◽  
Atte Joutsen ◽  
Brach Poston ◽  
Joshua Aizen ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Sensory Information ◽  
Initial Increase ◽  
Sensorimotor Training ◽  
Time Points ◽  
Posterior Parietal

Interplay between posterior parietal cortex (PPC) and ipsilateral primary motor cortex (M1) is crucial during execution of movements. The purpose of the study was to determine whether functional PPC–M1 connectivity in humans can be modulated by sensorimotor training. Seventeen participants performed a sensorimotor training task that involved tapping the index finger in synchrony to a rhythmic sequence. To explore differences in training modality, one group ( n = 8) learned by visual and the other ( n = 9) by auditory stimuli. Transcranial magnetic stimulation (TMS) was used to assess PPC–M1 connectivity before and after training, whereas electroencephalography (EEG) was used to assess PPC–M1 connectivity during training. Facilitation from PPC to M1 was quantified using paired-pulse TMS at conditioning-test intervals of 2, 4, 6, and 8 ms by measuring motor-evoked potentials (MEPs). TMS was applied at baseline and at four time points (0, 30, 60, and 180 min) after training. For EEG, task-related power and coherence were calculated for early and late training phases. The conditioned MEP was facilitated at a 2-ms conditioning-test interval before training. However, facilitation was abolished immediately following training, but returned to baseline at subsequent time points. Regional EEG activity and interregional connectivity between PPC and M1 showed an initial increase during early training followed by a significant decrease in the late phases. The findings indicate that parietal–motor interactions are activated during early sensorimotor training when sensory information has to be integrated into a coherent movement plan. Once the sequence is encoded and movements become automatized, PPC–M1 connectivity returns to baseline.

Connectivity Between Posterior Parietal Cortex and Ipsilateral Motor Cortex Is Altered in Schizophrenia

2008 ◽  
Vol 64 (9) ◽  
pp. 815-819 ◽  
Author(s):  
Giacomo Koch ◽  
Michele Ribolsi ◽  
Francesco Mori ◽  
Lucia Sacchetti ◽  
Claudia Codecà ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Posterior Parietal
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