Input to primate motor cortex from posterior parietal cortex (area 5). I. Demonstration by retrograde transport

1978 ◽  
Vol 157 (2) ◽  
pp. 325-330 ◽  
Author(s):  
P.L. Strick ◽  
C.C. Kim
Keyword(s):  
Motor Cortex ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Retrograde Transport ◽  
Area 5 ◽  
Cortex Area ◽  
Posterior Parietal

scholarly journals Neurophysiology of Prehension. III. Representation of Object Features in Posterior Parietal Cortex of the Macaque Monkey

2007 ◽  
Vol 98 (6) ◽  
pp. 3708-3730 ◽  
Author(s):  
Esther P. Gardner ◽  
K. Srinivasa Babu ◽  
Soumya Ghosh ◽  
Adam Sherwood ◽  
Jessie Chen
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Macaque Monkey ◽  
Firing Rates ◽  
Video Recordings ◽  
Object Properties ◽  
Area 5 ◽  
Somatosensory Input ◽  
Posterior Parietal ◽  
Object Features

Neurons in posterior parietal cortex (PPC) may serve both proprioceptive and exteroceptive functions during prehension, signaling hand actions and object properties. To assess these roles, we used digital video recordings to analyze responses of 83 hand-manipulation neurons in area 5 as monkeys grasped and lifted objects that differed in shape (round and rectangular), size (large and small spheres), and location (identical rectangular blocks placed lateral and medial to the shoulder). The task contained seven stages—approach, contact, grasp, lift, hold, lower, relax—plus a pretrial interval. The four test objects evoked similar spike trains and mean rate profiles that rose significantly above baseline from approach through lift, with peak activity at contact. Although representation by the spike train of specific hand actions was stronger than distinctions between grasped objects, 34% of these neurons showed statistically significant effects of object properties or hand postures on firing rates. Somatosensory input from the hand played an important role as firing rates diverged most prominently on contact as grasp was secured. The small sphere—grasped with the most flexed hand posture—evoked the highest firing rates in 43% of the population. Twenty-one percent distinguished spheres that differed in size and weight, and 14% discriminated spheres from rectangular blocks. Location in the workspace modulated response amplitude as objects placed across the midline evoked higher firing rates than positions lateral to the shoulder. We conclude that area 5 neurons, like those in area AIP, integrate object features, hand actions, and grasp postures during prehension.

scholarly journals Sequential sensory and decision processing in posterior parietal cortex

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Guilhem Ibos ◽  
David J Freedman
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Sensory Information ◽  
Matching Task ◽  
Visual Features ◽  
Motion Direction ◽  
Sensory Stimuli ◽  
Cortex Area ◽  
Visual Matching ◽  
Posterior Parietal

Decisions about the behavioral significance of sensory stimuli often require comparing sensory inference of what we are looking at to internal models of what we are looking for. Here, we test how neuronal selectivity for visual features is transformed into decision-related signals in posterior parietal cortex (area LIP). Monkeys performed a visual matching task that required them to detect target stimuli composed of conjunctions of color and motion-direction. Neuronal recordings from area LIP revealed two main findings. First, the sequential processing of visual features and the selection of target-stimuli suggest that LIP is involved in transforming sensory information into decision-related signals. Second, the patterns of color and motion selectivity and their impact on decision-related encoding suggest that LIP plays a role in detecting target stimuli by comparing bottom-up sensory inputs (what the monkeys were looking at) and top-down cognitive encoding inputs (what the monkeys were looking for).

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 Neurophysiology of Prehension. I. Posterior Parietal Cortex and Object-Oriented Hand Behaviors

2007 ◽  
Vol 97 (1) ◽  
pp. 387-406 ◽  
Author(s):  
Esther P. Gardner ◽  
K. Srinivasa Babu ◽  
Shari D. Reitzen ◽  
Soumya Ghosh ◽  
Alice S. Brown ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Related Area ◽  
Firing Rates ◽  
Sensorimotor Transformations ◽  
Area 5 ◽  
On Line ◽  
Posterior Parietal ◽  
Neuronal Spike Trains ◽  
Task Goals

Hand manipulation neurons in areas 5 and 7b/anterior intraparietal area (AIP) of posterior parietal cortex were analyzed in three macaque monkeys during a trained prehension task. Digital video recordings of hand kinematics synchronized to neuronal spike trains were used to correlate firing rates of 128 neurons with hand actions as the animals grasped and lifted rectangular and round objects. We distinguished seven task stages: approach, contact, grasp, lift, hold, lower, and relax. Posterior parietal cortex (PPC) firing rates were highest during object acquisition; 88% of task-related area 5 neurons and 77% in AIP/7b fired maximally during stages 1, 2, or 3. Firing rates rose 200–500 ms before contact, peaked at contact, and declined after grasp was secured. 83% of area 5 neurons and 72% in AIP/7b showed significant increases in mean rates during approach as the fingers were preshaped for grasp. Somatosensory signals at contact provided feedback concerning the accuracy of reach and helped guide the hand to grasp sites. In error trials, tactile information was used to abort grasp, or to initiate corrective actions to achieve task goals. Firing rates declined as lift began. 41% of area 5 neurons and 38% in AIP/7b were inhibited during holding, and returned to baseline when grasp was relaxed. Anatomical connections suggest that area 5 provides somesthetic information to circuits linking AIP/7b to frontal motor areas involved in grasping. Area 5 may also participate in sensorimotor transformations coordinating reach and grasp behaviors and provide on-line feedback needed for goal-directed hand movements.

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.

Lesions of Area 5 of the Posterior Parietal Cortex in the Cat Produce Errors in the Accuracy of Paw Placement During Visually Guided Locomotion

2007 ◽  
Vol 97 (3) ◽  
pp. 2339-2354 ◽  
Author(s):  
Kim Lajoie ◽  
Trevor Drew
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Major Change ◽  
Single Step ◽  
Visually Guided ◽  
Double Step ◽  
Area 5 ◽  
Posterior Parietal ◽  
Step Over ◽  
Standard Strategy

We developed a novel locomotor task in which cats step over obstacles that move at a different speed from that of the treadmill on which the cat is walking: we refer to this as a visual dissociation locomotion task. Slowing the speed of the obstacle with respect to that of the treadmill sometimes led to a major change in strategy so that cats made two steps with the hindlimbs before stepping over the obstacle (double step strategy) instead of the single step (standard strategy) observed when the obstacle was at the same speed as the treadmill. In addition, in the step preceding the step over the obstacle, the paws were placed significantly closer to the obstacle in the visual dissociation task than when the treadmill and the obstacle were at the same speed. After unilateral lesion of area 5 of the posterior parietal cortex (PPC), the cats frequently hit the obstacle as they stepped over it, especially in the visual dissociation task. This locomotor deficit was linked to significant differences in the location in which the forelimbs were placed in the step preceding that over the obstacle compared with the prelesion control. Cats also frequently hit the obstacle with their hindlimbs even when the forelimbs negotiated the obstacle successfully; this suggests an important role for the posterior parietal cortex in the coordination of the forelimbs and hindlimbs. Together, these results suggest an important contribution of the PPC to the planning of visually guided gait modifications.

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