scholarly journals Efficient cortical coding of 3D posture in freely behaving rats

Science ◽  
2018 ◽  
Vol 362 (6414) ◽  
pp. 584-589 ◽  
Author(s):  
Bartul Mimica ◽  
Benjamin A. Dunn ◽  
Tuce Tombaz ◽  
V. P. T. N. C. Srikanth Bojja ◽  
Jonathan R. Whitlock
Keyword(s):  
Motor Cortex ◽  
Posterior Parietal Cortex ◽  
Movement Planning ◽  
Three Dimensions ◽  
Population Code ◽  
Neural Signals ◽  
Ongoing Behavior ◽  
Posterior Parietal ◽  
Freely Behaving ◽  
Head Neck

Animals constantly update their body posture to meet behavioral demands, but little is known about the neural signals on which this depends. We therefore tracked freely foraging rats in three dimensions while recording from the posterior parietal cortex (PPC) and the frontal motor cortex (M2), areas critical for movement planning and navigation. Both regions showed strong tuning to posture of the head, neck, and back, but signals for movement were much less dominant. Head and back representations were organized topographically across the PPC and M2, and more neurons represented postures that occurred less often. Simultaneous recordings across areas were sufficiently robust to decode ongoing behavior and showed that spiking in the PPC tended to precede that in M2. Both the PPC and M2 strongly represent posture by using a spatially organized, energetically efficient population code.

scholarly journals Efficient cortical coding of 3D posture in freely behaving rats

2018 ◽  
Author(s):  
Bartul Mimica ◽  
Benjamin A. Dunn ◽  
Tuce Tombaz ◽  
V.P.T.N.C. Srikanth Bojja ◽  
Jonathan R. Whitlock
Keyword(s):  
Motor Cortex ◽  
Posterior Parietal Cortex ◽  
Movement Planning ◽  
Neural Signals ◽  
Efficient Manner ◽  
Spatial Movement ◽  
Ongoing Behavior ◽  
Posterior Parietal ◽  
Freely Behaving

In order to meet physical and behavioural demands of their environments animals constantly update their body posture, but little is known about the neural signals on which this ability depends. To better understand the role of cortex in coordinating natural pose and movement, we tracked the heads and backs of freely foraging rats in 3D while recording simultaneously from posterior parietal cortex (PPC) and frontal motor cortex (M2), areas critical for spatial movement planning and navigation. Single units in both regions were tuned mainly to postural features of the head, back and neck, and much less so to their movement. Representations of the head and back were organized topographically across PPC and M2, and the tuning peaks of the cells were distributed in an efficient manner, where substantially fewer cells encoded postures that occurred more often. Postural signals in both areas were sufficiently robust to allow reconstruction of ongoing behavior with 90% accuracy. Together, these findings demonstrate that both parietal and frontal motor cortices maintain an efficient, organized representation of 3D posture during unrestrained behavior.

scholarly journals Single Trial Decoding of Movement Intentions Using Functional Ultrasound Neuroimaging

2020 ◽  
Author(s):  
Sumner L. Norman ◽  
David Maresca ◽  
Vasileios N. Christopoulos ◽  
Whitney S. Griggs ◽  
Charlie Demene ◽  
...  
Keyword(s):  
High Performance ◽  
Posterior Parietal Cortex ◽  
Cerebral Blood Volume ◽  
Spatial Perception ◽  
Brain Area ◽  
Movement Planning ◽  
Neural Signals ◽  
Spatiotemporal Resolution ◽  
Posterior Parietal ◽  
Movement Intention

AbstractBrain-machine interfaces (BMI) are powerful devices for restoring function to people living with paralysis. Leveraging significant advances in neurorecording technology, computational power, and understanding of the underlying neural signals, BMI have enabled severely paralyzed patients to control external devices, such as computers and robotic limbs. However, high-performance BMI currently require highly invasive recording techniques, and are thus only available to niche populations. Here, we show that a minimally invasive neuroimaging approach based on functional ultrasound (fUS) imaging can be used to detect and decode movement intention signals usable for BMI. We trained non-human primates to perform memory-guided movements while using epidural fUS imaging to record changes in cerebral blood volume from the posterior parietal cortex – a brain area important for spatial perception, multisensory integration, and movement planning. Using hemodynamic signals acquired during movement planning, we classified left-cued vs. right-cued movements, establishing the feasibility of ultrasonic BMI. These results demonstrate the ability of fUS-based neural interfaces to take advantage of the excellent spatiotemporal resolution, sensitivity, and field of view of ultrasound without breaching the dura or physically penetrating brain tissue.

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

scholarly journals Neural encoding of actual and imagined touch within human posterior parietal cortex

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Srinivas Chivukula ◽  
Carey Y Zhang ◽  
Tyson Aflalo ◽  
Matiar Jafari ◽  
Kelsie Pejsa ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Semantic Processing ◽  
Posterior Parietal Cortex ◽  
Receptive Fields ◽  
Body Part ◽  
Neuronal Population ◽  
Movement Planning ◽  
Trial Participant ◽  
Imagery Task ◽  
Posterior Parietal

In the human posterior parietal cortex (PPC), single units encode high-dimensional information with partially mixed representations that enable small populations of neurons to encode many variables relevant to movement planning, execution, cognition, and perception. Here, we test whether a PPC neuronal population previously demonstrated to encode visual and motor information is similarly engaged in the somatosensory domain. We recorded neurons within the PPC of a human clinical trial participant during actual touch presentation and during a tactile imagery task. Neurons encoded actual touch at short latency with bilateral receptive fields, organized by body part, and covered all tested regions. The tactile imagery task evoked body part-specific responses that shared a neural substrate with actual touch. Our results are the first neuron-level evidence of touch encoding in human PPC and its cognitive engagement during a tactile imagery task, which may reflect semantic processing, attention, sensory anticipation, or imagined touch.

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