scholarly journals Dorsal Premotor Cortex Involved in Hand Gesture Preparation in Macaques

2019 ◽  
Author(s):  
Guanghao Sun ◽  
Shaomin Zhang ◽  
Ruixue Wang ◽  
Yaoyao Hao ◽  
Weidong Chen ◽  
...  
Keyword(s):  
Single Unit ◽  
Microelectrode Array ◽  
Premotor Cortex ◽  
Activity Patterns ◽  
Visual Stimuli ◽  
Single Unit Activity ◽  
Population Activity ◽  
Grasp Planning ◽  
Selection Strategies ◽  
Hand Shape

AbstractReaching to grasp movement is thought to rely upon two independent brain pathways. The dorsomedial one is involved in reaching while the dorsolateral one is dealing with grasping. However, some recent evidences suggested that the dorsomedial pathway might participate in grasp movement. Therefore, it is important to investigate whether PMd is involved in grasp planning, and if participating, what kind of role PMd played in grasp planning. In this study, two macaques monkeys were trained to grasp same object by instructing or freely choosing one of two grips, power grip or hook grip. A 96-channel microelectrode array was implanted to collect the population activity of PMd in each subject. Both single unit activity and population activity were analyzed. We found that nearly 21.0% and 26.8% units in PMd of two monkeys displayed grip selectivity during gesture planning in both instructing or freely choosing conditions. These units exhibit selectivity for different gestures when facing the identical visual stimuli (freely choosing condition). At the same time, similar activity patterns are displayed for the same gesture when faced with different selection strategies (freely choosing condition vs. instructing condition). These results show that some neurons of PMd are mainly involved in the hand shape preparation and have no obvious relationship with external visual stimuli and selection strategies.

scholarly journals Continuous multiplexed population representations of task context in the mouse primary visual cortex

2021 ◽  
Author(s):  
Marton Albert Hajnal ◽  
Duy Tran ◽  
Michael Einstein ◽  
Mauricio Vallejo Martelo ◽  
Karen Safaryan ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Activity Patterns ◽  
Visual Stimuli ◽  
Stimulus Onset ◽  
Decision Task ◽  
Cognitive Variables ◽  
Task Context ◽  
Population Activity ◽  
V1 Neurons

Primary visual cortex (V1) neurons integrate motor and multisensory information with visual inputs during sensory processing. However, whether V1 neurons also integrate and encode higher-order cognitive variables is less understood. We trained mice to perform a context-dependent cross-modal decision task where the interpretation of identical audio-visual stimuli depends on task context. We performed silicon probe population recordings of neuronal activity in V1 during task performance and showed that task context (whether the animal should base its decision on visual or auditory stimuli) can be decoded during both intertrial intervals and stimulus presentations. Context and visual stimuli were represented in overlapping populations but were orthogonal in the population activity space. Context representation was not static but displayed distinctive dynamics upon stimulus onset and offset. Thus, activity patterns in V1 independently represent visual stimuli and cognitive variables relevant to task execution.

P279 Distribution of single unit activity patterns in subthalamic nucleus of Parkinsonian patients

2017 ◽  
Vol 128 (9) ◽  
pp. e267
Author(s):  
Elena Belova ◽  
Artem Nezvinskiy ◽  
Ulia Semenova ◽  
Svetlana Usova ◽  
Valentin Popov ◽  
...  
Keyword(s):  
Subthalamic Nucleus ◽  
Unit Activity ◽  
Single Unit ◽  
Activity Patterns ◽  
Single Unit Activity

scholarly journals Neural dynamics of variable grasp movement preparation in the macaque fronto-parietal network

2017 ◽  
Author(s):  
Jonathan A Michaels ◽  
Benjamin Dann ◽  
Rijk W Intveld ◽  
Hansjörg Scherberger
Keyword(s):  
Parietal Cortex ◽  
Premotor Cortex ◽  
Initial Population ◽  
Movement Preparation ◽  
Reach To Grasp ◽  
Movement Initiation ◽  
Preparation Time ◽  
Population Activity ◽  
Grasp Planning ◽  
Macaque Monkeys

AbstractOur voluntary grasping actions lie on a continuum between immediate action and waiting for the right moment, depending on the context. Therefore, studying grasping requires investigating how preparation time affects this process. Two macaque monkeys (Macaca mulatta) performed a grasping task with a short instruction followed by an immediate or delayed go cue (0-1300 ms) while we recorded in parallel from neurons in the hand area (F5) of the ventral premotor cortex and the anterior intraparietal area (AIP). Initial population dynamics followed a fixed trajectory in the neural state space unique to each grip type, reflecting unavoidable preparation, then diverged depending on the delay. Although similar types of single unit responses were present in both areas, population activity in AIP stabilized within a unique memory state while F5 activity continued to evolve, tracking subjective anticipation of the go cue. Intriguingly, activity during movement initiation clustered into two trajectory clusters, corresponding to movements that were either ‘as fast as possible’ or withheld movements, demonstrating a widespread state shift in the fronto-parietal grasping network when movements must be withheld. Our results reveal how dissociation between static and dynamic components of movement preparation as well as differentiation between cortical areas is possible through population level analysis.Significance StatementMany of our movements must occur with no warning, while others we can prepare in advance. Yet, it’s unclear how planning for movements along the spectrum between these two situations differs in the brain. Two macaque monkeys made reach to grasp movements after varying amounts of preparation time while we recorded from premotor and parietal cortex. We found that the initial response to a grasp instruction was specific to the required movement, but not the preparation time, reflecting required processing. However, when more preparation time was given, neural activity achieved unique states that likely related to withholding movements and anticipation of movement, which was more prevalent in premotor cortex, suggesting differing roles of premotor and parietal cortex in grasp planning.

scholarly journals Leveraging non-human primate multisensory neurons and circuits in assessing consciousness theory

2019 ◽  
Author(s):  
Jean-Paul Noel ◽  
Yumiko Ishizawa ◽  
Shaun R. Patel ◽  
Emad N. Eskandar ◽  
Mark T. Wallace
Keyword(s):  
Single Unit ◽  
Subjective Experience ◽  
Premotor Cortex ◽  
Single Unit Activity ◽  
Neuronal Responses ◽  
Perceptual Awareness ◽  
Tactile Stimuli ◽  
Co Activation ◽  
Integrated Information Theory ◽  
Human Primate

AbstractBoth the Global Neuronal Workspace (GNW) and Integrated Information Theory (IIT) posit that highly complex and interconnected networks engender perceptual awareness. GNW specifies that activity recruiting fronto-parietal networks will elicit a subjective experience, while IIT is more concerned with the functional architecture of networks than with activity within it. Here, we argue that according to IIT mathematics, circuits converging on integrative vs. convergent yet non-integrative neurons should support a greater degree of consciousness. We test this hypothesis by analyzing a dataset of neuronal responses collected simultaneously from primary somatosensory cortex (S1) and ventral premotor cortex (vPM) in non-human primates presented with auditory, tactile, and audio-tactile stimuli as they are progressively anesthetized with Propofol. We first describe the multisensory (audio-tactile) characteristics of S1 and vPM neurons (mean and dispersion tendencies, as well as noise-correlations), and functionally label these neurons as convergent or integrative according to their spiking responses. Then, we characterize how these different pools of neurons behave as a function of consciousness. At odds with the IIT mathematics, results suggest that convergent neurons more readily exhibit properties of consciousness (neural complexity and noise correlation) and are more impacted during the loss of consciousness than integrative neurons. Lastly, we provide support for the GNW by showing that neural ignition (i.e., same trial co-activation of S1 and vPM) was more frequent in conscious than unconscious states. Overall, we contrast GNW and IIT within the same single-unit activity dataset, and support the GNW.

scholarly journals Dynamic neuronal activation of a distributed cortico-basal ganglia-thalamus loop in learning a delayed sensorimotor task

2019 ◽  
Author(s):  
Xiaowei Gu ◽  
Chengyu T. Li
Keyword(s):  
Basal Ganglia ◽  
Neuronal Activity ◽  
Weak Interaction ◽  
Unit Activity ◽  
Single Unit ◽  
Premotor Cortex ◽  
Single Unit Activity ◽  
Functional Interaction ◽  
Sensorimotor Transformation ◽  
Related Information

AbstractThe cortico-basal ganglia-thalamus (CBT) loop is important for behavior. However, the activity and learning-related modulation within the loop in behavior remain unclear. To tackle this problem, we trained mice to perform a delayed sensorimotor-transformation task and recorded single-unit activity during learning simultaneously from four regions in a CBT loop: prelimbic area (PrL), posterior premotor cortex (pM2), dorsomedial caudate/putamen (dmCP), and mediodorsal thalamus (MD). Sensory and decision related information were encoded by the neurons within the loop, with weak interaction among neurons of different coding ability. The functional interaction among regions within the loop was dynamically routed in the loop during different behavioral phases and contributed to explain decision-related neuronal activity. The neurons of PrL and dmCP exhibited learning-related reorganization in neuronal activity and more persistent coding of sensory and decision-related information. Thus, both sensory- and decision-related information are processed in a functionally interacted CBT loop that is modulated by learning.

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