Applications of predictive control in neuroscience

2013 ◽  
Vol 36 (3) ◽  
pp. 208-208
Author(s):  
Bruce Bridgeman
Keyword(s):  
Motor Cortex ◽  
Predictive Control ◽  
Receptive Fields ◽  
Sensory Cortex ◽  
Visual World ◽  
Stimulus Properties ◽  
Unexpected Stimulus

AbstractThe sensory cortex has been interpreted as coding information rather than stimulus properties since Sokolov in 1960 showed increased response to an unexpected stimulus decrement. The motor cortex is also organized around expectation, coding the goal of an act rather than a set of muscle movements. Expectation drives not only immediate responses but also the very structure of the cortex, as demonstrated by development of receptive fields that mirror the structure of the visual world.

Brain adaptation to chronic hypobaric hypoxia in rats

1992 ◽  
Vol 72 (6) ◽  
pp. 2238-2243 ◽  
Author(s):  
J. C. LaManna ◽  
L. M. Vendel ◽  
R. M. Farrell
Keyword(s):  
Blood Flow ◽  
Motor Cortex ◽  
Microvessel Density ◽  
Hypobaric Hypoxia ◽  
Regional Blood Flow ◽  
Oxygen Availability ◽  
Sensory Cortex ◽  
Hypoxic Exposure ◽  
Normal Brain ◽  
Tissue Po2

Rats were exposed to hypobaric hypoxia (0.5 atm) for up to 3 wk. Hypoxic rats failed to gain weight but maintained normal brain water and ion content. Blood hematocrit was increased by 48% to a level of 71% after 3 wk of hypoxia compared with littermate controls. Brain blood flow was increased by an average of 38% in rats exposed to 15 min of 10% normobaric oxygen and by 23% after 3 h but was not different from normobaric normoxic rats after 3 wk of hypoxia. Sucrose space, as a measure of brain plasma volume, was not changed under any hypoxic conditions. The mean brain microvessel density was increased by 76% in the frontopolar cerebral cortex, 46% in the frontal motor cortex, 54% in the frontal sensory cortex, 65% in the parietal motor cortex, 68% in the parietal sensory cortex, 68% in the hippocampal CA1 region, 57% in the hippocampal CA3 region, 26% in the striatum, and 56% in the cerebellum. The results indicate that hypoxia elicits three main responses that affect brain oxygen availability. The acute effect of hypoxia is an increase in regional blood flow, which returns to control levels on continued hypoxic exposure. Longer-term effects of continued moderate hypoxic exposure are erythropoiesis and a decrease in intercapillary distance as a result of angiogenesis. The rise in hematocrit and the increase in microvessel density together increase oxygen availability to the brain to within normal limits, although this does not imply that tissue PO2 is restored to normal.

Anatomical analysis of ventrolateral thalamic input to primate motor cortex

1976 ◽  
Vol 39 (5) ◽  
pp. 1020-1031 ◽  
Author(s):  
P. L. Strick
Keyword(s):  
Motor Cortex ◽  
Retrograde Transport ◽  
Sensory Cortex ◽  
Central Sulcus ◽  
Thalamic Neurons ◽  
Thalamic Input ◽  
Continuous Slab ◽  
Ventrolateral Thalamus ◽  
Point To Point ◽  
Somatic Sensory Cortex

1. The origin and topographical organization of input to the arm area of the primate motor cortex from the ventrolateral thalamus were examined using the method of retrograde transport of horseradish peroxidase (HRP). 2. A thin, continuous slab of labeled neurons was found in the ventrolateral thalamus followingmultiple injections of HRP into the arm area of the motor cortex. The slab of labeled neurons was flanked, medially and laterally, by groups of unlabeled neurons. 3. The origin of ventrolateral thalamic input was more extensive than previously thought. Labeled neurons were found from A10.0 to A6.0 and occurred in three ventolateral thalamic subdivisions: ventralis lateralis pars oralis (VLo), ventralis lateralis pars caudalis (VLc), and ventralis posterior lateralis pars oralis (VPLo). For simplicity this region containing labeled neurons has been termed the ventrolateral thalamic (VL) arm area. 4. Injections of HRP into the somatic sensory cortex indicated that the thalamic regions which project to the somatic sensory cortex are separate from the VL arm area. 5. The distribution of labeled neurons following single injections of HRP into different regions of the motor cortex arm area indicated that the VL arm area is topographically organized, particularly its caudal part. Ventral regions of the VL arm area were labeled following HRP injections into motor cortex regions adjacent to the central sulcus where the representation of largely distal musculature is localized. Dorsal regions of the VL arm area were labeled following HRP injections into motor cortex regions more rostral to the central sulcus where the representation of more proximal musculature is localized. 6. A larger region of the VL arm area was labeled following HRP injections adjacent to the central sulcus than following the more rostral motor cortex injections. This suggests that, like the arm area of the motor cortex, more of the VL arm area is allotted to the representation of distal than proximal musculature. 7. Following very small cortical HRP injections, isolated labeled thalamic neurons were diffusely scattered throughout a 3-mm rostrocaudal extent of the VL arm area. In addition, a small focal cluster of labeled thalamic neurons was also seen. The labeled cluster was limited to 0.5 mm rostrocaudally and 300 mum in width. The focal distribution of labeled thalamic neurons suggests that aspects of a point to point organization may exist in the connection between VL and the motor cortex arm area.

Input-output properties of hand-related cells in the ventral cingulate cortex in the monkey

1995 ◽  
Vol 73 (6) ◽  
pp. 2584-2590 ◽  
Author(s):  
G. Cadoret ◽  
A. M. Smith
Keyword(s):  
Index Finger ◽  
Receptive Fields ◽  
Sensory Cortex ◽  
Cellular Activity ◽  
Finger Force ◽  
Input Output ◽  
High Concentration ◽  
Strong Activity ◽  
Excitatory Responses ◽  
Rostral Part

1. Neurons with proprioceptive or cutaneous receptive fields associated with the hand were identified in the ventral bank of the cingulate sulcus in the monkey. Cells with proprioceptive fields outnumbered cells receiving cutaneous afferents by more than three to one. No cells were encountered that received convergent proprioceptive and cutaneous input. The high concentration of these neurons in the lateral depth of the cingulate sulcus establishes that a distinct hand representation exists within the rostral part of area 23c. 2. Hand-related neurons in area 23c exhibited strong activity modulations during grasping, lifting, and holding an object with the contralateral thumb and index finger. Force pulse perturbations applied to the object elicited excitatory responses at latencies of approximately 45 ms. The modulation of the cellular activity and the input-output properties of these cingulate neurons suggest that, like neurons of primary motor and sensory cortex, these cingulate neurons are also involved in the sensorimotor control of finger movements.

scholarly journals Spatial precision of population activity in primate area MT

2015 ◽  
Vol 114 (2) ◽  
pp. 869-878 ◽  
Author(s):  
Spencer C. Chen ◽  
John W. Morley ◽  
Samuel G. Solomon
Keyword(s):  
Neural Activity ◽  
Visual Processing ◽  
Receptive Fields ◽  
Object Motion ◽  
Spatial Position ◽  
Multielectrode Arrays ◽  
Visual World ◽  
Population Activity ◽  
Area Mt ◽  
Mt Neurons

The middle temporal (MT) area is a cortical area integral to the “where” pathway of primate visual processing, signaling the movement and position of objects in the visual world. The receptive field of a single MT neuron is sensitive to the direction of object motion but is too large to signal precise spatial position. Here, we asked if the activity of MT neurons could be combined to support the high spatial precision required in the where pathway. With the use of multielectrode arrays, we recorded simultaneously neural activity at 24–65 sites in area MT of anesthetized marmoset monkeys. We found that although individual receptive fields span more than 5° of the visual field, the combined population response can support fine spatial discriminations (<0.2°). This is because receptive fields at neighboring sites overlapped substantially, and changes in spatial position are therefore projected onto neural activity in a large ensemble of neurons. This fine spatial discrimination is supported primarily by neurons with receptive fields flanking the target locations. Population performance is degraded (by 13–22%) when correlations in neural activity are ignored, further reflecting the contribution of population neural interactions. Our results show that population signals can provide high spatial precision despite large receptive fields, allowing area MT to represent both the motion and the position of objects in the visual world.

scholarly journals Comparing Cerebellar and Motor Cortical Activity in Reaching and Grasping

1993 ◽  
Vol 20 (S3) ◽  
pp. S53-S61 ◽  
Author(s):  
M. Smith Allan ◽  
Dugas Clause ◽  
Fortier Pierre ◽  
Kalasha John ◽  
Picard Nathalie
Keyword(s):  
Motor Cortex ◽  
Cortical Neurons ◽  
Grip Force ◽  
Single Cells ◽  
Receptive Fields ◽  
Movement Direction ◽  
Arm Reaching ◽  
Anticipatory Activity ◽  
Motor Strategies ◽  
Premotor Areas

ABSTRACT:The activity of single cells in the cerebellar and motor cortex of awake monkeys was recorded during separate studies of whole-arm reaching movements and during the application of force-pulse perturbations to handheld objects. Two general observations about the contribution of the cerebellum to the control of movement emerge from the data. The first, derived from the study of whole arm reaching, suggests that although both the motor cortex and cerebellum generate a signal related to movement direction, the cerebellar signal is less precise and varies from trial to trial even when the movement kinematics remain unchanged. The second observation, derived from the study of predictable perturbations of a hand-held object, indicates that cerebellar cortical neurons better reflect preparatory motor strategies formed from the anticipation of cutaneous and proprioceptive stimuli acquired by previous experience. In spite of strong relations to grip force and receptive fields stimulated by preparatory grip forces increase, the neurons of the percentral motor cortex showed very little anticipatory activity compared with either the premotor areas or the cerebellum.

scholarly journals Sensory cortex is optimised for prediction of future input

2017 ◽  
Author(s):  
Yosef Singer ◽  
Yayoi Teramoto ◽  
Ben D. B. WiIJmore ◽  
Andrew J. King ◽  
Jan W. H. Schnupp ◽  
...  
Keyword(s):  
Sensory Processing ◽  
Cortical Neurons ◽  
Sensory Input ◽  
Receptive Fields ◽  
Primary Auditory Cortex ◽  
Feedforward Neural Networks ◽  
Sensory Cortex ◽  
Natural Scenes ◽  
Recent Past ◽  
The Brain

Neurons in sensory cortex are tuned to diverse features in natural scenes. But what determines which features neurons become selective to? Here we explore the idea that neuronal selectivity is optimised to represent features in the recent past of sensory input that best predict immediate future inputs. We tested this hypothesis using simple feedforward neural networks, which were trained to predict the next few video or audio frames in clips of natural scenes. The networks developed receptive fields that closely matched those of real cortical neurons, including the oriented spatial tuning of primary visual cortex, the frequency selectivity of primary auditory cortex and, most notably, in their temporal tuning properties. Furthermore, the better a network predicted future inputs the more closely its receptive fields tended to resemble those in the brain. This suggests that sensory processing is optimised to extract those features with the most capacity to predict future input.Impact statementPrediction of future input explains diverse neural tuning properties in sensory cortex.

Activity in Rostral Motor Cortex in Response to Predictable Force-Pulse Perturbations in a Precision Grip Task

2001 ◽  
Vol 86 (3) ◽  
pp. 1079-1085 ◽  
Author(s):  
Marie-Josée Boudreau ◽  
Allan M. Smith
Keyword(s):  
Motor Cortex ◽  
Index Finger ◽  
Precision Grip ◽  
Receptive Fields ◽  
Vertical Displacement ◽  
Warning Stimulus ◽  
Force Pulse ◽  
Pulse Perturbation ◽  
Anticipatory Activity ◽  
Proprioceptive Inputs

The purpose of this investigation was to characterize the discharge of neurons in the rostral area 4 motor cortex (MI) during performance of a precision grip task. Three monkeys were trained to grasp an object between the thumb and index finger and to lift and hold it stationary for 2–2.5 s within a narrow position window. The grip and load forces and the vertical displacement of the object were recorded on each trial. On some trials a downward force-pulse perturbation generating a shear force and slip on the skin was applied to the object after 1.5 s of static holding. In total, 72 neurons were recorded near the rostral limit of the hand area of the motor cortex, located close to the premotor areas. Of these, 30 neurons were examined for receptive fields, and all 30 were found to receive proprioceptive inputs from finger muscles. Intracortical microstimulation applied to 38 recording sites evoked brief hand movements, most frequently involving the thumb and index finger with an average threshold of 12 μA. Slightly more than one-half of the neurons (38/72) demonstrated significant increases in firing rate that on average began 284 ± 186 ms before grip onset. Of 54 neurons tested with predictable force-pulse perturbations, 29 (53.7%) responded with a reflexlike reaction at a mean latency of 54.2 ± 16.8 ms. This latency was 16 ms longer than the mean latency of reflexlike activity evoked in neurons with proprioceptive receptive fields in the more caudal motor cortex. No neurons exhibited anticipatory activity that preceded the perturbation even when the perturbations were delivered randomly and signaled by a warning stimulus. The results indicate the presence of a strong proprioceptive input to the rostral motor cortex, but raise the possibility that the afferent pathway or intracortical processing may be different because of the slightly longer latency.

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