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.

Activity of most rostral ventromedial medulla neurons reflect EEG/EMG pattern changes

1989 ◽  
Vol 257 (6) ◽  
pp. R1496-R1505 ◽  
Author(s):  
D. A. Grahn ◽  
H. C. Heller
Keyword(s):  
Single Unit ◽  
Cortical Activation ◽  
Rostral Ventromedial Medulla ◽  
Emg Activity ◽  
Single Unit Activity ◽  
Neuronal Responses ◽  
Peripheral Stimulation ◽  
Ventromedial Medulla ◽  
Emg Patterns ◽  
Eeg Pattern

Studies in lightly anesthetized animals have demonstrated neurons in the rostral ventromedial medulla (RVM) that respond to specific modalities of peripheral stimulation. We initiated this study to investigate putative thermoafferent processing in such RVM neurons. Our results indicate that most RVM neuronal responses are not specific for the applied stimulus but reflect changes in cortical activation. Electroencephalogram/electromyogram (EEG/EMG) and RVM single unit activity was recorded in lightly urethan-anesthetized rats. Five distinct EEG/EMG patterns were observed. Their expression was a function of skin and core temperatures. Pinches and strong thermal manipulations caused a desynchronization of a synchronized EEG pattern and an increase in EMG activity. The activity of 38 of the 51 RVM neurons sampled correlated with changes in EEG/EMG activity. Thirteen neurons were not affected by changes in EEG/EMG activity. One unit responded to temperature manipulations within an EEG/EMG state, suggesting that a small portion of RVM neurons may transmit thermoafferent information.

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 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.

Effect of Eye Opening on Single-Unit Activity and Local Field Potentials in the Subthalamic Nucleus

2017 ◽  
Vol 20 (5) ◽  
pp. 471-477 ◽  
Author(s):  
Arun Chockalingam ◽  
Abigail Belasen ◽  
Nita Chen ◽  
Adolfo Ramirez-Zamora ◽  
Youngwon Youn ◽  
...  
Keyword(s):  
Subthalamic Nucleus ◽  
Local Field ◽  
Unit Activity ◽  
Single Unit ◽  
Local Field Potentials ◽  
Single Unit Activity ◽  
Field Potentials ◽  
Eye Opening
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