scholarly journals Spatio-Temporal Pattern Representation from AI Inspired Brain Model in Spiking Neural Network

2021 ◽  
Vol 12 (5) ◽  
pp. 6618-6631
Keyword(s):  
Motor Neurons ◽  
Visual Stimuli ◽  
Spatial Domain ◽  
Brain Network ◽  
The Body ◽  
Domain Modeling ◽  
Population Activity ◽  
Temporal Domain ◽  
Spatio Temporal ◽  
The Brain

Neuronal population activity in the brain is the combined response of information in the spatial domain and dynamics in the temporal domain. Modeling such Spatio-temporal mechanisms is a complex process because of the complexity of the brain and the limitations of the hardware. In this paper, we demonstrate how information processing principles adapted from the brain can be used to create a brain-inspired artificial intelligence (AI) model and represent Spatio-temporal patterns. The same is demonstrated by designing the tiny brain using spiking neural networks, where activated neuronal populations represent information in the spatial domain and transmitting signals represent dynamics in the temporal domain. Spatially located sensory neurons excited by input visual stimuli further activate motor neurons to trigger a motor response that causes behavior modification of the robotic agent. Initially, an isolated brain network is simulated to understand the excitation part from sensory to motor neurons while plotting waveform between membrane potential and time. The response of the network to stimulate robot body movements is also plotted to demonstrate representation. The simulation shows how the response of particular visual stimuli modifies behavior and helps us understand the body and brain synchronization. The perceived environment and resultant behavior response allow us to study body interaction with the environment.

scholarly journals Interpreting Neuronal Population Activity by Reconstruction: Unified Framework With Application to Hippocampal Place Cells

1998 ◽  
Vol 79 (2) ◽  
pp. 1017-1044 ◽  
Author(s):  
Kechen Zhang ◽  
Iris Ginzburg ◽  
Bruce L. McNaughton ◽  
Terrence J. Sejnowski
Keyword(s):  
Bayesian Methods ◽  
Neuronal Population ◽  
Place Cells ◽  
The Body ◽  
Unified Framework ◽  
Population Activity ◽  
Reconstruction Methods ◽  
Special Cases ◽  
Physical Variables ◽  
The Brain

Zhang, Kechen, Iris Ginzburg, Bruce L. McNaughton, and Terrence J. Sejnowski. Interpreting neuronal population activity by reconstruction: unified framework with application to hippocampal place cells. J. Neurophysiol. 79: 1017–1044, 1998. Physical variables such as the orientation of a line in the visual field or the location of the body in space are coded as activity levels in populations of neurons. Reconstruction or decoding is an inverse problem in which the physical variables are estimated from observed neural activity. Reconstruction is useful first in quantifying how much information about the physical variables is present in the population and, second, in providing insight into how the brain might use distributed representations in solving related computational problems such as visual object recognition and spatial navigation. Two classes of reconstruction methods, namely, probabilistic or Bayesian methods and basis function methods, are discussed. They include important existing methods as special cases, such as population vector coding, optimal linear estimation, and template matching. As a representative example for the reconstruction problem, different methods were applied to multi-electrode spike train data from hippocampal place cells in freely moving rats. The reconstruction accuracy of the trajectories of the rats was compared for the different methods. Bayesian methods were especially accurate when a continuity constraint was enforced, and the best errors were within a factor of two of the information-theoretic limit on how accurate any reconstruction can be and were comparable with the intrinsic experimental errors in position tracking. In addition, the reconstruction analysis uncovered some interesting aspects of place cell activity, such as the tendency for erratic jumps of the reconstructed trajectory when the animal stopped running. In general, the theoretical values of the minimal achievable reconstruction errors quantify how accurately a physical variable is encoded in the neuronal population in the sense of mean square error, regardless of the method used for reading out the information. One related result is that the theoretical accuracy is independent of the width of the Gaussian tuning function only in two dimensions. Finally, all the reconstruction methods considered in this paper can be implemented by a unified neural network architecture, which the brain feasibly could use to solve related problems.

scholarly journals Microstimulation in the primary visual cortex: activity patterns and their relation to visual responses and evoked saccades

2020 ◽  
Author(s):  
R. Oz ◽  
H. Edelman-Klapper ◽  
S. Nivinsky-Margalit ◽  
H. Slovin
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Neural Activity ◽  
Visual Processing ◽  
Visual Stimuli ◽  
Temporal Patterns ◽  
Visual Responses ◽  
Population Activity ◽  
Spatio Temporal ◽  
Saccade Generation

AbstractIntra cortical microstimulation (ICMS) in the primary visual cortex (V1) can generate the visual perception of phosphenes and evoke saccades directed to the stimulated location in the retinotopic map. Although ICMS is widely used, little is known about the evoked spatio-temporal patterns of neural activity and their relation to neural responses evoked by visual stimuli or saccade generation. To investigate this, we combined ICMS with Voltage Sensitive Dye Imaging in V1 of behaving monkeys and measured neural activity at high spatial (meso-scale) and temporal resolution. Small visual stimuli and ICMS evoked population activity spreading over few mm that propagated to extrastriate areas. The population responses evoked by ICMS showed faster dynamics and different spatial propagation patterns. Neural activity was higher in trials w/saccades compared with trials w/o saccades. In conclusion, our results uncover the spatio-temporal patterns evoked by ICMS and their relation to visual processing and saccade generation.

scholarly journals COMMUNIST CAROTIC ARTERY CLOSURE DURATION EFFECT ON WISTAR WHITE RATS MOTORIC

2021 ◽  
Vol 1 (Volume 1 No 2) ◽  
pp. 153-164
Author(s):  
Daswara Djajasasmita ◽  
Hindung Sa'adah ◽  
Miftahudin
Keyword(s):  
Carotid Artery ◽  
Motor Function ◽  
Motor Neurons ◽  
Carotid Arteries ◽  
The Body ◽  
Literature Study ◽  
Motor Functions ◽  
White Rats ◽  
Duration Effect ◽  
The Brain

The carotid artery consists of two carotid arteries, namely the dextra communist artery and the sinistra, the main blood vessels in the neck that supply blood to the brain, the basal ganglia, which have the function of regulating the motor functions of the body. The communal carotid arteries blocked flow can cause brain ischemia. It is due to hypoxia due to a lack of oxygen supply carried by the brain, resulting in motor body function disorders, incredible blockages in the carotid arteries that supply blood to the brain, and neurons as regulators of motor functions. The research is a literature study that has relevance to the formulation of the problem meets the criteria and research objectives to determine the effect of the length of the blockage of the arteries of the carotid artery of the communist to the motor function of the Wistar strain rats. The results of a literature review or literature studies in some previous scientific research journals indicate if the blockage of the arteries of the communal carotid arteries affects the disruption of motor function caused by hypoxia and damage to neurons and brain tissue in motor neurons. The conclusion is that the blockage and the duration of blockage of the communal carotid arteries affect motor function.

The Brain/MINDS project aimed at establishing the marmoset as a model organism for neurobiology and establishing the genetic and biochemical elements of their neural development

Impact ◽  
2018 ◽  
Vol 2018 (3) ◽  
pp. 86-88
Author(s):  
Tomomi Shimogori
Keyword(s):  
Human Brain ◽  
Brain Development ◽  
Molecular Mechanisms ◽  
Mental Disease ◽  
Visual Stimuli ◽  
The Body ◽  
Proper Function ◽  
Newborn Mouse ◽  
Model Animal ◽  
The Brain

The brain is the most sophisticated and intricate organ in the body. Billions of neurons interconnect and form distinct regions which process different neural activities. The development of the brain during pregnancy and early post-natal life is extremely sensitive, complex and crucial to proper function over the life of a person. This is the most plastic time of the brain. It is changing constantly and reacting to the different stimuli encountered by the individual. The lack of a particular stimulus can have a profound effect on the later structure and function of the brain. For example, if a newborn mouse has an eye covered so it receives no light, visual cortex, where normally processes binocular visual stimuli, develops to process visual stimuli only from the open eye. This cannot be altered later on even when both eyes are opened; the mouse remains weak in one eye despite there being nothing wrong with the eye itself. Studying this early time period of brain development presents many problems. Investigation is hampered by the difficulty in accessing and manipulating the brain as well as the huge variety of factors that contribute to brain development. Currently, most work is conducted in rodents, primarily because there are a large range of genetic tools available. This is useful to an extent and has demonstrated key findings that appear to be relevant to most mammalian species. However, the human brain is quite different to the mouse brain. It has adapted to very different tasks required of mice compared to humans and therefore there is a knowledge gap to bridge in this area. In addition to this, examination of global gene expression in the brain has only truly become viable in the last 10 years. The same can also be said of the ability to analyse the development process at a biochemical level. Dr Tomomi Shimogori of the RIKEN Center for Brain Science, Japan, has been tackling these difficulties through her work on the molecular mechanisms of brain development. She has worked on rodents, but is now developing a model in the common marmoset based around the creation of a gene atlas. Working on the primate should help fill in the gap between rodent and human. Shimogori explains why the marmoset was chosen: 'One of the biggest advantages of using marmosets as a model animal is that many of its behaviours share similarities with human behaviours, and thus has potential for use in understanding the underlying mechanisms of human brain function and mental disease

scholarly journals Explicit control of step timing during split-belt walking reveals interdependent recalibration of movements in space and time

2019 ◽  
Author(s):  
Marcela Gonzalez-Rubio ◽  
Nicolas F. Velasquez ◽  
Gelsy Torres-Oviedo
Keyword(s):  
Motor Adaptation ◽  
Spatial Domain ◽  
Hierarchical Organization ◽  
The Other ◽  
Spatial Control ◽  
Limb Position ◽  
Locomotor Pattern ◽  
Temporal Domain ◽  
Temporal Features ◽  
Spatio Temporal

ABSTRACTSplit-belt treadmills that move the legs at different speeds are thought to update internal representations of the environment, such that this novel condition generates a new locomotor pattern with distinct spatio-temporal features compared to those of regular walking. It is unclear the degree to which such recalibration of movements in the spatial and temporal domains is interdependent. In this study, we explicitly altered subjects’ limb motion in either space or time during split-belt walking to determine its impact on the adaptation of the other domain. Interestingly, we observed that motor adaptation in the spatial domain was susceptible to altering the temporal domain, whereas motor adaptation in the temporal domain was resilient to modifying the spatial domain. This nonreciprocal relation suggests a hierarchical organization such that the control of timing in locomotion has an effect on the control of limb position. This is of translational interest because clinical populations often have a greater deficit in one domain compared to the other. Our results suggest that explicit changes to temporal deficits cannot occur without modifying the spatial control of the limb.

scholarly journals Visual experience shapes the neural networks remapping touch into external space

2017 ◽  
Author(s):  
Virginie Crollen ◽  
Latifa Lazzouni ◽  
Mohamed Rezk ◽  
Antoine Bellemare ◽  
Franco Lepore ◽  
...  
Keyword(s):  
Visual Experience ◽  
Temporal Order Judgment ◽  
Interaction Analysis ◽  
Brain Network ◽  
Visual Deprivation ◽  
The Body ◽  
External Space ◽  
Touch Perception ◽  
Congenitally Blind ◽  
The Brain

AbstractLocalizing touch relies on the activation of skin-based and externally defined spatial frames of references. Psychophysical studies have demonstrated that early visual deprivation prevents the automatic remapping of touch into external space. We used fMRI to characterize how visual experience impacts on the brain circuits dedicated to the spatial processing of touch. Sighted and congenitally blind humans (male and female) performed a tactile temporal order judgment (TOJ) task, either with the hands uncrossed or crossed over the body midline. Behavioral data confirmed that crossing the hands has a detrimental effect on TOJ judgments in sighted but not in blind. Crucially, the crossed hand posture elicited more activity in a fronto-parietal network in the sighted group only. Psychophysiological interaction analysis revealed that the congenitally blind showed enhanced functional connectivity between parietal and frontal regions in the crossed versus uncrossed hand postures. Our results demonstrate that visual experience scaffolds the neural implementation of touch perception.Significance statementAlthough we seamlessly localize tactile events in our daily life, it is not a trivial operation because the hands move constantly within the peripersonal space. To process touch correctly, the brain has therefore to take the current position of the limbs into account and remap them to their location in the external world. In sighted, parietal and premotor areas support this process. However, while visual experience has been suggested to support the implementation of the automatic external remapping of touch, no studies so far have investigated how early visual deprivation alters the brain network supporting touch localization. Examining this question is therefore crucial to conclusively determine the intrinsic role vision plays in scaffolding the neural implementation of touch perception.

scholarly journals A size principle for leg motor control in Drosophila

2019 ◽  
Author(s):  
Anthony W Azevedo ◽  
Evyn S Dickinson ◽  
Pralaksha Gurung ◽  
Lalanti Venkatasubramanian ◽  
Richard Mann ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Fruit Fly ◽  
The Body ◽  
Hierarchical Organization ◽  
Dependent Manner ◽  
Size Principle ◽  
Specific Order ◽  
The Brain ◽  
Ballistic Movements

SummaryTo move the body, the brain must precisely coordinate patterns of activity among diverse populations of motor neurons. In many species, including vertebrates, the motor neurons innervating a given muscle fire in a specific order that is determined by a gradient of cellular size and electrical excitability. This hierarchy allows premotor circuits to recruit motor neurons of increasing force capacity in a task-dependent manner. However, it remains unclear whether such a size principle also applies to species with more compact motor systems, such as the fruit fly, Drosophila melanogaster, which has just 53 motor neurons per leg. Using in vivo calcium imaging and electrophysiology, we found that genetically-identified motor neurons controlling flexion of the fly tibia exhibit a gradient of anatomical, physiological, and functional properties consistent with the size principle. Large, fast motor neurons control high force, ballistic movements while small, slow motor neurons control low force, postural movements. Intermediate neurons fall between these two extremes. In behaving flies, motor neurons are recruited in order from slow to fast. This hierarchical organization suggests that slow and fast motor neurons control distinct motor regimes. Indeed, we find that optogenetic manipulation of each motor neuron type has distinct effects on the behavior of walking flies.

scholarly journals Development of the Brain Functional Connectome Follows Puberty-Dependent Nonlinear Trajectories

2020 ◽  
Author(s):  
Zeus Gracia-Tabuenca ◽  
Martha Beatriz Moreno ◽  
Fernando Barrios ◽  
Sarael Alcauter
Keyword(s):  
Cognitive Flexibility ◽  
Functional Organization ◽  
Morphological Changes ◽  
Brain Network ◽  
The Body ◽  
Brain Organization ◽  
Functional Connectome ◽  
Nonlinear Trends ◽  
The Impact ◽  
The Brain

AbstractAdolescence is a developmental period that dramatically impacts body and behavior, with pubertal hormones playing an important role not only in the morphological changes in the body but also in brain structure and function. Understanding brain development during adolescence has become a priority in neuroscience because it coincides with the onset of many psychiatric and behavioral disorders. However, little is known about how puberty influences the brain functional connectome. In this study, taking a longitudinal human sample of typically developing children and adolescents (of both sexes), we demonstrate that the development of the brain functional connectome better fits pubertal status than chronological age. In particular, centrality, segregation, efficiency, and integration of the brain functional connectome increase after the onset of the pubertal markers. We found that these effects are stronger in attention and task control networks. Lastly, after controlling for this effect, we showed that functional connectivity between these networks is related to better performance in cognitive flexibility. This study points out the importance of considering longitudinal nonlinear trends when exploring developmental trajectories, and emphasizes the impact of puberty on the functional organization of the brain in adolescence.Significance StatementUnderstanding the brain organization along development is a crucial challenge for Neuroscience. In particular, during adolescence there is a great impact in body and cognitive functions as well as substantial incidence of mental health disruptions. Here, we tested how brain organization changes along this period based on the properties of the functional connectome in a longitudinal pediatric sample. We found a nonlinear increase in the connectivity and the brain network efficiency, particularly after the onset of puberty. These effects were more prominent in association networks. In addition, higher connectivity in those areas was associated with better performance in cognitive flexibility. These results demonstrate the importance of considering pubertal assessment as well as nonlinear trends in developmental studies.

scholarly journals A novel 5D brain parcellation approach based on spatio-temporal encoding of resting fMRI data from deep residual learning

2021 ◽  
Author(s):  
Behnam Kazemivash ◽  
Vince D. Calhoun
Keyword(s):  
Temporal Dynamics ◽  
Brain Network ◽  
Brain Anatomy ◽  
Temporal Networks ◽  
Residual Network ◽  
Brain Organization ◽  
Spatial And Temporal Dynamics ◽  
Temporal Encoding ◽  
Spatio Temporal ◽  
The Brain

AbstractObjectiveBrain parcellation is an essential aspect of computational neuroimaging research and deals with segmenting the brain into (possibly overlapping) sub-regions employed to study brain anatomy or function. In the context of functional parcellation, brain organization which is often measured via temporal metrics such as coherence, is highly dynamic. This dynamic aspect is ignored in most research, which typically applies anatomically based, fixed regions for each individual, and can produce misleading results.MethodsIn this work, we propose a novel spatio-temporal-network (5D) brain parcellation scheme utilizing a deep residual network to predict the probability of each voxel belonging to a brain network at each point in time.ResultsWe trained 53 4D brain networks and evaluate the ability of these networks to capture spatial and temporal dynamics as well as to show sensitivity to individual or group-level variation (in our case with age).ConclusionThe proposed system generates informative spatio-temporal networks that vary not only across individuals but also over time and space.SignificanceThe dynamic 5D nature of the developed approach provides a powerful framework that expands on existing work and has potential to identify novel and typically ignored findings when studying the healthy and disordered brain.

scholarly journals White-matter degradation and dynamical compensation support age-related functional alterations in human brain

2022 ◽  
Author(s):  
Spase Petkoski ◽  
Petra Ritter ◽  
Viktor Jirsa
Keyword(s):  
Average Length ◽  
Temporal Structure ◽  
Structural Connectivity ◽  
Bimodal Distribution ◽  
Brain Network ◽  
Age Related ◽  
Spatio Temporal ◽  
The Individual ◽  
The Impact ◽  
The Brain

Structural connectivity of the brain at different ages is analyzed using diffusion-weighted Magnetic Resonance Imaging (MRI) data. The largest decrease of the number and average length of stream- lines is found for the long inter-hemispheric links, with the strongest impact for frontal regions. From the BOLD functional MRI (fMRI) time series we identify age-related changes of dynamic functional connectivity (dFC) and spatial covariation features of the FC links captured by meta- connectivity (MC). They indicate more constant dFC, but wider range and variance of MC. Finally we applied computational whole-brain network model based on oscillators, which mechanistically expresses the impact of the spatio-temporal structure of the brain (weights and the delays) to the dynamics. With this we tested several hypothesis, which revealed that the spatio-temporal reorga- nization of the brain with ageing, supports the observed functional fingerprints only if the model accounts for: (i) compensation of the individual brains for the overall loss of structural connectivity, and (ii) decrease of propagation velocity due to the loss of myelination. We also show that having these two conditions, it is sufficient to decompose the time-delays as bimodal distribution that only distinguishes between intra- and inter-hemispheric delays, and that the same working point also captures the static FC the best.

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