scholarly journals No effect of triple-pulse TMS medial to intraparietal sulcus on online correction for target perturbations during goal-directed hand and foot reaches

2019 ◽  
Author(s):  
Daniel S. Marigold ◽  
Kim Lajoie ◽  
Tobias Heed
Keyword(s):  
Posterior Parietal Cortex ◽  
Lateral Position ◽  
Movement Planning ◽  
Intraparietal Sulcus ◽  
Target Displacement ◽  
Online Correction ◽  
Negative Results ◽  
Central Regions ◽  
Posterior Parietal ◽  
Lateral Localization

AbstractPosterior parietal cortex (PPC) is central to sensorimotor processing for goal-directed hand and foot movements. Yet, the specific role of PPC subregions in these functions is not clear. Previous human neuroimaging and transcranial magnetic stimulation (TMS) work has suggested that PPC lateral to the intraparietal sulcus (IPS) is involved in directing the arm, shaping the hand, and correcting both finger-shaping and hand trajectory during movement. The lateral localization of these functions agrees with the comparably lateral position of the hand and fingers within the motor and somatosensory homunculi along the central sulcus; this might suggest that, in analogy, (goal-directed) foot movements would be mediated by medial portions of PPC. However, foot movement planning activates similar regions for both hand and foot movement along the caudal-to-rostral axis of PPC, with some effector-specificity evident only rostrally, near the central regions of sensorimotor cortex. Here, we attempted to test the causal involvement of PPC regions medial to IPS in hand and foot reaching as well as online correction evoked by target displacement. Participants made hand and foot reaches towards identical visual targets. Sometimes, the target changed position 100-117 ms into the movement. We disturbed cortical processing over four positions medial to IPS with three pulses of TMS separated by 40 ms, both during trials with and without target displacement. We timed TMS to disrupt reach execution and online correction. TMS did not affect endpoint error, endpoint variability, or reach trajectories for hand or foot. While these negative results await replication with different TMS timing and parameters, we conclude that regions medial to IPS are involved in planning, rather than execution and online control, of goal-directed limb movements.

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.

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.

scholarly journals Mental Reversal of Imagined Melodies: A Role for the Posterior Parietal Cortex

2010 ◽  
Vol 22 (4) ◽  
pp. 775-789 ◽  
Author(s):  
Robert J. Zatorre ◽  
Andrea R. Halpern ◽  
Marc Bouffard
Keyword(s):  
Posterior Parietal Cortex ◽  
Parietal Lobe ◽  
Memory Load ◽  
Neural Substrates ◽  
Imagery Task ◽  
Intraparietal Sulcus ◽  
Musical Imagery ◽  
Mental Transformation ◽  
Posterior Parietal ◽  
Visual Domain

Two fMRI experiments explored the neural substrates of a musical imagery task that required manipulation of the imagined sounds: temporal reversal of a melody. Musicians were presented with the first few notes of a familiar tune (Experiment 1) or its title (Experiment 2), followed by a string of notes that was either an exact or an inexact reversal. The task was to judge whether the second string was correct or not by mentally reversing all its notes, thus requiring both maintenance and manipulation of the represented string. Both experiments showed considerable activation of the superior parietal lobe (intraparietal sulcus) during the reversal process. Ventrolateral and dorsolateral frontal cortices were also activated, consistent with the memory load required during the task. We also found weaker evidence for some activation of right auditory cortex in both studies, congruent with results from previous simpler music imagery tasks. We interpret these results in the context of other mental transformation tasks, such as mental rotation in the visual domain, which are known to recruit the intraparietal sulcus region, and we propose that this region subserves general computations that require transformations of a sensory input. Mental imagery tasks may thus have both task or modality-specific components as well as components that supersede any specific codes and instead represent amodal mental manipulation.

scholarly journals The posterior parietal cortex contributes to visuomotor processing for saccades in blindsight macaques

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Rikako Kato ◽  
Takuya Hayashi ◽  
Kayo Onoe ◽  
Masatoshi Yoshida ◽  
Hideo Tsukada ◽  
...  
Keyword(s):  
Visual Field ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Visual Awareness ◽  
Functional Brain Imaging ◽  
Intraparietal Sulcus ◽  
Visual Responses ◽  
Primate Model ◽  
Positron Emission ◽  
Posterior Parietal

AbstractPatients with damage to the primary visual cortex (V1) lose visual awareness, yet retain the ability to perform visuomotor tasks, which is called “blindsight.” To understand the neural mechanisms underlying this residual visuomotor function, we studied a non-human primate model of blindsight with a unilateral lesion of V1 using various oculomotor tasks. Functional brain imaging by positron emission tomography showed a significant change after V1 lesion in saccade-related visuomotor activity in the intraparietal sulcus area in the ipsi- and contralesional posterior parietal cortex. Single unit recordings in the lateral bank of the intraparietal sulcus (lbIPS) showed visual responses to targets in the contralateral visual field on both hemispheres. Injection of muscimol into the ipsi- or contralesional lbIPSs significantly impaired saccades to targets in the V1 lesion-affected visual field, differently from previous reports in intact animals. These results indicate that the bilateral lbIPSs contribute to visuomotor function in blindsight.

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 Integration of target and hand position signals in the posterior parietal cortex: effects of workspace and hand vision

2012 ◽  
Vol 108 (1) ◽  
pp. 187-199 ◽  
Author(s):  
Christopher A. Buneo ◽  
Richard A. Andersen
Keyword(s):  
Parietal Cortex ◽  
Visual Cues ◽  
Posterior Parietal Cortex ◽  
Single Cells ◽  
Arm Movement ◽  
Movement Planning ◽  
Hand Position ◽  
Position Information ◽  
Limb Position ◽  
Posterior Parietal

Previous findings suggest the posterior parietal cortex (PPC) contributes to arm movement planning by transforming target and limb position signals into a desired reach vector. However, the neural mechanisms underlying this transformation remain unclear. In the present study we examined the responses of 109 PPC neurons as movements were planned and executed to visual targets presented over a large portion of the reaching workspace. In contrast to previous studies, movements were made without concurrent visual and somatic cues about the starting position of the hand. For comparison, a subset of neurons was also examined with concurrent visual and somatic hand position cues. We found that single cells integrated target and limb position information in a very consistent manner across the reaching workspace. Approximately two-thirds of the neurons with significantly tuned activity (42/61 and 30/46 for left and right workspaces, respectively) coded targets and initial hand positions separably, indicating no hand-centered encoding, whereas the remaining one-third coded targets and hand positions inseparably, in a manner more consistent with the influence of hand-centered coordinates. The responses of both types of neurons were largely invariant with respect to the presence or absence of visual hand position cues, suggesting their corresponding coordinate frames and gain effects were unaffected by cue integration. The results suggest that the PPC uses a consistent scheme for computing reach vectors in different parts of the workspace that is robust to changes in the availability of somatic and visual cues about hand position.

scholarly journals NEURAL ENCODING OF FELT AND IMAGINED TOUCH WITHIN HUMAN POSTERIOR PARIETAL CORTEX

2020 ◽  
Author(s):  
Srinivas Chivukula ◽  
Carey 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 ◽  
Motor Information ◽  
Posterior Parietal

ABSTRACTIn 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 selective in the somatosensory domain. We recorded from 1423 neurons within the PPC of a human clinical trial participant during objective touch presentation and during tactile imagery. Neurons encoded experienced touch with bilateral receptive fields, organized by body part, and covered all tested regions. Tactile imagery evoked body part specific responses that shared a neural substrate with experienced touch. Our results are the first neuron level evidence of touch encoding in human PPC and its cognitive engagement during tactile imagery which may reflect semantic processing, sensory anticipation, and imagined touch.

scholarly journals Afferent connections of cytoarchitectural area 6M and surrounding cortex in the marmoset: putative homologues of the supplementary and pre-supplementary motor areas

2021 ◽  
Author(s):  
Sophia Bakola ◽  
Kathleen J Burman ◽  
Sylwia Bednarek ◽  
Jonathan M Chan ◽  
Natalia Jermakov ◽  
...  
Keyword(s):  
Posterior Parietal Cortex ◽  
Movement Planning ◽  
Posterior Cingulate ◽  
Planning And Control ◽  
Cortical Motor ◽  
Cingulate Motor Area ◽  
Posterior Parietal ◽  
And Control ◽  
Premotor Areas ◽  
Motor Areas

Cortical projections to the caudomedial frontal cortex were studied using retrograde tracers in marmosets. We tested the hypothesis that cytoarchitectural area 6M includes homologues of the supplementary and pre-supplementary motor areas (SMA and preSMA) of other primates. We found that, irrespective of the injection sites' location within 6M, over half of the labeled neurons were located in motor and premotor areas. Other connections originated in prefrontal area 8b, ventral anterior and posterior cingulate areas, somatosensory areas (3a and 1-2), and areas on the rostral aspect of the dorsal posterior parietal cortex. Although the origin of afferents was similar, injections in rostral 6M received higher percentages of prefrontal afferents, and fewer somatosensory afferents, compared to caudal injections, compatible with differentiation into SMA and preSMA. Injections rostral to 6M (area 8b) revealed a very different set of connections, with increased emphasis in prefrontal and posterior cingulate afferents, and fewer parietal afferents. The connections of 6M were also quantitatively different from those of M1, dorsal premotor areas, and cingulate motor area 24d. These results show that the cortical motor control circuit is conserved in simian primates, indicating that marmosets can be valuable models for studying movement planning and control.

Sign in / Sign up

Export Citation Format

Share Document