Reacquisition Deficits in Prism Adaptation After Muscimol Microinjection Into the Ventral Premotor Cortex of Monkeys

1999 ◽  
Vol 81 (4) ◽  
pp. 1927-1938 ◽  
Author(s):  
Kiyoshi Kurata ◽  
Eiji Hoshi
Keyword(s):  
Visual Field ◽  
Target Location ◽  
Premotor Cortex ◽  
Prism Adaptation ◽  
Horizontal Distance ◽  
Visually Guided ◽  
Dorsal Premotor Cortex ◽  
Reaching Task ◽  
Ventral Premotor Cortex ◽  
Target Locations

Reacquisition deficits in prism adaptation after muscimol microinjection into the ventral premotor cortex of monkeys. A small amount of muscimol (1 μl; concentration, 5 μg/μl) was injected into the ventral and dorsal premotor cortex areas (PMv and PMd, respectively) of monkeys, which then were required to perform a visually guided reaching task. For the task, the monkeys were required to reach for a target soon after it was presented on a screen. While performing the task, the monkeys’ eyes were covered with left 10°, right 10°, or no wedge prisms, for a block of 50–100 trials. Without the prisms, the monkeys reached the targets accurately. When the prisms were placed, the monkeys initially misreached the targets because the prisms displaced the visual field. Before the muscimol injection, the monkeys adapted to the prisms in 10–20 trials, judging from the horizontal distance between the target location and the point where the monkey touched the screen. After muscimol injection into the PMv, the monkeys lost the ability to readapt and touched the screen closer to the location of the targets as seen through the prisms. This deficit was observed at selective target locations, only when the targets were shifted contralaterally to the injected hemisphere. When muscimol was injected into the PMd, no such deficits were observed. There were no changes in the reaction and movement times induced by muscimol injections in either area. The results suggest that the PMv plays an important role in motor learning, specifically in recalibrating visual and motor coordinates.

Laterality of Movement-Related Activity Reflects Transformation of Coordinates in Ventral Premotor Cortex and Primary Motor Cortex of Monkeys

2007 ◽  
Vol 98 (4) ◽  
pp. 2008-2021 ◽  
Author(s):  
Kiyoshi Kurata
Keyword(s):  
Motor Cortex ◽  
Neuronal Activity ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Visuomotor Transformation ◽  
Related Activity ◽  
Reaching Task ◽  
Ventral Premotor Cortex ◽  
Cortical Motor ◽  
Target Locations

The ventral premotor cortex (PMv) and the primary motor cortex (MI) of monkeys participate in various sensorimotor integrations, such as the transformation of coordinates from visual to motor space, because the areas contain movement-related neuronal activity reflecting either visual or motor space. In addition to relationship to visual and motor space, laterality of the activity could indicate stages in the visuomotor transformation. Thus we examined laterality and relationship to visual and motor space of movement-related neuronal activity in the PMv and MI of monkeys performing a fast-reaching task with the left or right arm, toward targets with visual and motor coordinates that had been dissociated by shift prisms. We determined laterality of each activity quantitatively and classified it into four types: activity that consistently depended on target locations in either head-centered visual coordinates (V-type) or motor coordinates (M-type) and those that had either differential or nondifferential activity for both coordinates (B- and N-types). A majority of M-type neurons in the areas had preferences for reaching movements with the arm contralateral to the hemisphere where neuronal activity was recorded. In contrast, most of the V-type neurons were recorded in the PMv and exhibited less laterality than the M-type. The B- and N-types were recorded in the PMv and MI and exhibited intermediate properties between the V- and M-types when laterality and correlations to visual and motor space of them were jointly examined. These results suggest that the cortical motor areas contribute to the transformation of coordinates to generate final motor commands.

Modest Gaze-Related Discharge Modulation in Monkey Dorsal Premotor Cortex During a Reaching Task Performed With Free Fixation

2002 ◽  
Vol 88 (2) ◽  
pp. 1064-1072 ◽  
Author(s):  
Paul Cisek ◽  
John F. Kalaska
Keyword(s):  
Premotor Cortex ◽  
Cell Activity ◽  
Delay Period ◽  
Gaze Direction ◽  
Dorsal Premotor Cortex ◽  
Experimental Conditions ◽  
Reaching Task ◽  
Oculomotor Behavior ◽  
Arm Reaching ◽  
Gaze Angle

Recent studies have shown that gaze angle modulates reach-related neural activity in many cortical areas, including the dorsal premotor cortex (PMd), when gaze direction is experimentally controlled by lengthy periods of imposed fixation. We looked for gaze-related modulation in PMd during the brief fixations that occur when a monkey is allowed to look around freely without experimentally imposed gaze control while performing a center-out delayed arm-reaching task. During the course of the instructed-delay period, we found significant effects of gaze angle in 27–51% of PMd cells. However, for 90–95% of cells, these effects accounted for <20% of the observed discharge variance. The effect of gaze was significantly weaker than the effect of reach-related variables. In particular, cell activity during the delay period was more strongly related to the intended movement expressed in arm-related coordinates than in gaze-related coordinates. Under the same experimental conditions, many cells in medial parietal cortex exhibited much stronger gaze-related modulation and expressed intended movement in gaze-related coordinates. In summary, gaze direction-related modulation of cell activity is indeed expressed in PMd during the brief fixations that occur in natural oculomotor behavior, but its overall effect on cell activity is modest.

Differential Involvement of Neurons in the Dorsal and Ventral Premotor Cortex During Processing of Visual Signals for Action Planning

2006 ◽  
Vol 95 (6) ◽  
pp. 3596-3616 ◽  
Author(s):  
Eiji Hoshi ◽  
Jun Tanji
Keyword(s):  
Neuronal Activity ◽  
Visual Information ◽  
Visual Cues ◽  
Target Location ◽  
Premotor Cortex ◽  
Action Planning ◽  
Visual Signals ◽  
Visual Cue ◽  
Ventral Premotor Cortex ◽  
Neuron Response

We examined neuronal activity in the dorsal and ventral premotor cortex (PMd and PMv, respectively) to explore the role of each motor area in processing visual signals for action planning. We recorded neuronal activity while monkeys performed a behavioral task during which two visual instruction cues were given successively with an intervening delay. One cue instructed the location of the target to be reached, and the other indicated which arm was to be used. We found that the properties of neuronal activity in the PMd and PMv differed in many respects. After the first cue was given, PMv neuron response mostly reflected the spatial position of the visual cue. In contrast, PMd neuron response also reflected what the visual cue instructed, such as which arm to be used or which target to be reached. After the second cue was given, PMv neurons initially responded to the cue's visuospatial features and later reflected what the two visual cues instructed, progressively increasing information about the target location. In contrast, the activity of the majority of PMd neurons responded to the second cue with activity reflecting a combination of information supplied by the first and second cues. Such activity, already reflecting a forthcoming action, appeared with short latencies (<400 ms) and persisted throughout the delay period. In addition, both the PMv and PMd showed bilateral representation on visuospatial information and motor-target or effector information. These results further elucidate the functional specialization of the PMd and PMv during the processing of visual information for action planning.

Modulation of preparatory neuronal activity in dorsal premotor cortex due to stimulus-response compatibility

1994 ◽  
Vol 71 (3) ◽  
pp. 1281-1284 ◽  
Author(s):  
D. J. Crammond ◽  
J. F. Kalaska
Keyword(s):  
Neuronal Activity ◽  
Premotor Cortex ◽  
Spatial Location ◽  
Dorsal Premotor Cortex ◽  
Reaching Task ◽  
Stimulus Response ◽  
Sustained Activity ◽  
Spatial Attributes ◽  
Direction Of Movement ◽  
Selection Of

1. Neuronal activity was recorded in the dorsal premotor cortex (PMd) of two monkeys performing a multidirectional, instructed-delay (ID) reaching task in which visuospatial cues signaled the direction of movement either congruent with the instruction cue ("direct-delay" trials, DD) or redirected 180 degrees opposite to the cue ("redirected-delay" trials, RD). Therefore, this task had two degrees of stimulus-response (S-R) compatibility because in one-half of the trials the spatial attributes of the visual cue were incongruent with those of the intended movement. 2. The majority of PMd cells discharged both at short latency to the RD or DD cues and subsequently with sustained activity during the remaining ID period (IDP). The earliest responses (< 250 ms) in both DD and RD trials covaried with cue location and so could be either a "visuospatial" response or a neuronal correlate of the selection of action with highest S-R compatibility, namely move to the stimulus. In contrast, later IDP activity usually covaried with the direction of movement signaled by the cues, independent of their spatial location, supporting the hypothesis that IDP discharge in PMd ultimately encodes attributes of intended reaching movements.

scholarly journals Spatiotemporal dynamics of brain activity during the transition from visually guided to memory-guided force control

2012 ◽  
Vol 108 (5) ◽  
pp. 1335-1348 ◽  
Author(s):  
Cynthia Poon ◽  
Lisa G. Chin-Cottongim ◽  
Stephen A. Coombes ◽  
Daniel M. Corcos ◽  
David E. Vaillancourt
Keyword(s):  
Prefrontal Cortex ◽  
Visual Feedback ◽  
Central Region ◽  
Force Control ◽  
Brain Activity ◽  
Premotor Cortex ◽  
Feedback Gain ◽  
Visually Guided ◽  
Ventral Premotor Cortex ◽  
Ventral Prefrontal Cortex

It is well established that the prefrontal cortex is involved during memory-guided tasks whereas visually guided tasks are controlled in part by a frontal-parietal network. However, the nature of the transition from visually guided to memory-guided force control is not as well established. As such, this study examines the spatiotemporal pattern of brain activity that occurs during the transition from visually guided to memory-guided force control. We measured 128-channel scalp electroencephalography (EEG) in healthy individuals while they performed a grip force task. After visual feedback was removed, the first significant change in event-related activity occurred in the left central region by 300 ms, followed by changes in prefrontal cortex by 400 ms. Low-resolution electromagnetic tomography (LORETA) was used to localize the strongest activity to the left ventral premotor cortex and ventral prefrontal cortex. A second experiment altered visual feedback gain but did not require memory. In contrast to memory-guided force control, altering visual feedback gain did not lead to early changes in the left central and midline prefrontal regions. Decreasing the spatial amplitude of visual feedback did lead to changes in the midline central region by 300 ms, followed by changes in occipital activity by 400 ms. The findings show that subjects rely on sensorimotor memory processes involving left ventral premotor cortex and ventral prefrontal cortex after the immediate transition from visually guided to memory-guided force control.

scholarly journals Object-based attention shifts are driven by target location, not object placement

2018 ◽  
Author(s):  
Adam J. Barnas ◽  
Adam Greenberg
Keyword(s):  
Visual Field ◽  
Target Location ◽  
Attention Shift ◽  
Specific Target ◽  
Attentional Resources ◽  
Object Locations ◽  
Object Based ◽  
Target Locations ◽  
Attention Shifts

Object-based attention (OBA) enhances processing within an attended object. We previously found that attention shifts that crossed the visual field meridians were faster horizontally than vertically, which we named a Shift Direction Anisotropy (SDA). We aimed to determine whether the SDA depends upon attention shift meridian crossings of object boundaries, target locations, or both. Participants viewed an ‘L’-shaped object and responded to a target at the cued vertex location (valid) or at non-cued object locations offset horizontally (invalid-horizontal) or vertically (invalid-vertical). In Experiment 1, object boundaries and target locations were positioned either crossing or not crossing the meridians. In Experiments 2A and 2B, object boundaries were held constant (always crossing or never crossing the meridians, respectively) while target locations were manipulated (randomly crossing or non-crossing). In Experiments 3A and 3B, target locations were held constant while object boundaries were manipulated. In Experiment 4, the object was removed to determine whether object-based or space-based attentional resources were being deployed. The SDA emerged only when target locations necessitated shifts that crossed the meridians, regardless of object placement, demonstrating that the SDA is driven by target location relative to the meridians and that OBA processes prioritize specific target locations within an object.

Directional Selectivity of BOLD Activity in Human Posterior Parietal Cortex for Memory-Guided Double-Step Saccades

2006 ◽  
Vol 95 (3) ◽  
pp. 1645-1655 ◽  
Author(s):  
W. Pieter Medendorp ◽  
Herbert C. Goltz ◽  
Tutis Vilis
Keyword(s):  
Visual Field ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Target Location ◽  
Double Step ◽  
Fmri Signal ◽  
Posterior Parietal ◽  
Visual Hemifields ◽  
Target Locations

We used functional magnetic resonance imaging (fMRI) to investigate the role of the human posterior parietal cortex (PPC) in storing target locations for delayed double-step saccades. To do so, we exploited the laterality of a subregion of PPC that preferentially responds to the memory of a target location presented in the contralateral visual field. Using an event-related design, we tracked fMRI signal changes in this region while subjects remembered the locations of two sequentially flashed targets, presented in either the same or different visual hemifields, and then saccaded to them in sequence. After presentation of the first target, the fMRI signal was always related to the side of the visual field in which it had been presented. When the second target was added, the cortical activity depended on the respective locations of both targets but was still significantly selective for the target of the first saccade. We conclude that this region within the human posterior parietal cortex not only acts as spatial storage center by retaining target locations for subsequent saccades but is also involved in selecting the target for the first intended saccade.

Movement-Related Neuronal Activity Reflecting the Transformation of Coordinates in the Ventral Premotor Cortex of Monkeys

2002 ◽  
Vol 88 (6) ◽  
pp. 3118-3132 ◽  
Author(s):  
Kiyoshi Kurata ◽  
Eiji Hoshi
Keyword(s):  
Neuronal Activity ◽  
Primary Motor Cortex ◽  
Linear Models ◽  
Target Location ◽  
Movement Time ◽  
Premotor Cortex ◽  
Visual Space ◽  
Behavioral Task ◽  
Movement Onset ◽  
Ventral Premotor Cortex

We examined how the transformation of coordinates from visual to motor space is reflected by neuronal activity in the ventral premotor cortex (PMv) of monkeys. Three monkeys were trained to reach with their right hand for a target that appeared on a screen. While performing the task, the monkeys wore prisms that shifted the image of the target 10°, left or right, or wore no prisms, for a block of 200 trials. The nine targets were located in the same positions in visual space regardless of whether the prisms were present. Wearing the prisms required the monkeys to initiate a movement in a direction that was different from the apparent target location. Thus using the prisms, we could dissociate visual space from motor space. While the monkey performed the behavioral task, we recorded neuronal activity in the left PMv and primary motor cortex (MI), and various kinds of task-related neuronal activity were found in the motor areas. These included neurons that changed their activity during a reaction time (RT) period (the period between target presentation and movement onset), which were called “movement-related neurons” and selected for analysis. In these neurons, activity during a movement time (MT) period was also compared. Using general linear models for our statistical analysis, the neurons were then classified into four types: those whose activity was consistently dependent on location of targets in the visual coordinates regardless of whether the prisms were present or absent (V type); those that were consistently dependent on target location in the motor coordinates only; those that had different activity for both of the motor and visual coordinates; and those that had nondifferential activity for the two types of coordinates. The proportion of the four types of the neurons differed significantly between the PMv and MI. Most remarkably, neurons with V-type activity were almost exclusively recorded in the PMv and were almost exclusively found during the RT period. Such activity was never observed in an electromyogram of the working forelimb. Based on these observations, we postulate that the V and other types may represent the various intermediate stages of the transformation of coordinates and that the PMv plays a crucial role in transforming coordinates from visual to motor space.

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