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Neuronal Ensemble
A neuronal ensemble is a population of nervous system cells (or cultured neurons) involved in a particular neural computation. Background The concept of neuronal ensemble dates back to the work of Charles Sherrington who described the functioning of the CNS as the system of reflex arcs, each composed of interconnected excitatory and inhibitory neurons. In Sherrington's scheme, α-motoneurons are the final common path of a number of neural circuits of different complexity: motoneurons integrate a large number of inputs and send their final output to muscles. Donald Hebb theoretically developed the concept of neuronal ensemble in his famous book "The Organization of Behavior" (1949). He defined "cell assembly" as "a diffuse structure comprising cells in the cortex and diencephalon, capable of acting briefly as a closed system, delivering facilitation to other such systems". Hebb suggested that, depending on functional requirements, individual brain cells could participate in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nervous System
In biology, the nervous system is the complex system, highly complex part of an animal that coordinates its behavior, actions and sense, sensory information by transmitting action potential, signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events. Nervous tissue first arose in Ediacara biota, wormlike organisms about 550 to 600 million years ago. In Vertebrate, vertebrates, it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers, or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor nerves (efferent), while those nerves that transmit information from the body to the CNS are called sensory nerves (aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Cortex
The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and then reaches the visual cortex. The area of the visual cortex that receives the sensory input from the lateral geniculate nucleus is the primary visual cortex, also known as visual area 1 ( V1), Brodmann area 17, or the striate cortex. The extrastriate areas consist of visual areas 2, 3, 4, and 5 (also known as V2, V3, V4, and V5, or Brodmann area 18 and all Brodmann area 19). Both hemispheres of the brain include a visual cortex; the visual cortex in the left hemisphere receives signals from the right visual field, and the visual cortex in the right hemisphere receives signals from the left visual field. Introduction The primary visual cortex (V1) is located in and around the calcarine fissure in the occipital lobe. Each h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miguel Nicolelis
Miguel Ângelo Laporta Nicolelis (, born March 7, 1961), is a Brazilian scientist, physician and Duke School of Medicine Professor in Neuroscience at Duke University, best known for his pioneering work surrounding brain-computer interface (also known as "brain-machine interface") technology. Biography Nicolelis holds a medical degree from the University of São Paulo (1984), a doctorate in Sciences (General Physiology) from the University of São Paulo (1989) and a PhD in Physiology and Biophysics from Hahnemann University (now Drexel University College of Medicine). He is a full professor in the Department of Neurobiology and Co-Director of the Neuroengineering Center at Duke University (USA). Founder of the Alberto Santos Dumont Association for Research Support (AASDAP) and the Santos Dumont Institute (ISD), he proposed the use of science as an agent of social and economic transformation. Nicolelis is a Researcher at the International Institute of Neurosciences Edmond and Li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain–computer Interface
A brain–computer interface (BCI), sometimes called a brain–machine interface (BMI), is a direct communication link between the brain's electrical activity and an external device, most commonly a computer or robotic limb. BCIs are often directed at researching, Brain mapping, mapping, assisting, Augmented cognition, augmenting, or repairing human Cognitive skill, cognitive or Sensory-motor coupling, sensory-motor functions. They are often conceptualized as a human–machine interface that skips the intermediary of moving body parts (e.g. hands or feet). BCI implementations range from non-invasive (EEG, Magnetoencephalography, MEG, MRI) and partially invasive (ECoG and endovascular) to invasive (microelectrode array), based on how physically close electrodes are to brain tissue. Research on BCIs began in the 1970s by Jacques Vidal at the University of California, Los Angeles (UCLA) under a grant from the National Science Foundation, followed by a contract from the Defense Adva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DARPA
The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Advanced Research Projects Agency (ARPA), the agency was created on February 7, 1958, by President Dwight D. Eisenhower in response to the Soviet Union, Soviet launching of Sputnik 1 in 1957. By collaborating with academia, industry, and government partners, DARPA formulates and executes research and development projects to expand the frontiers of technology and science, often beyond immediate U.S. military requirements.Dwight D. Eisenhower and Science & Technology, (2008). Dwight D. Eisenhower Memorial CommissionSource The name of the organization first changed from its founding name, ARPA, to DARPA, in March 1972, changing back to ARPA in February 1993, then reverted to DARPA in March 1996. ''The Economist'' has called DARPA "the agency that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Decoding
Neural decoding is a neuroscience field concerned with the hypothetical reconstruction of sensory and other stimuli from information that has already been encoded and represented in the brain by biological neural network, networks of neurons. Reconstruction refers to the ability of the researcher to predict what sensory stimuli the subject is receiving based purely on neuron action potentials. Therefore, the main goal of neural decoding is to characterize how the Electrophysiology, electrical activity of neurons elicit activity and responses in the brain. This article specifically refers to neural decoding as it pertains to the mammalian neocortex. Overview When looking at a picture, people's brains are constantly making decisions about what object they are looking at, where they need to move their eyes next, and what they find to be the most salient aspects of the input stimulus. As these images hit the back of the retina, these stimuli are converted from varying wavelengths to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain
The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for special senses such as visual perception, vision, hearing, and olfaction. Being the most specialized organ, it is responsible for receiving information from the sensory nervous system, processing that information (thought, cognition, and intelligence) and the coordination of motor control (muscle activity and endocrine system). While invertebrate brains arise from paired segmental ganglia (each of which is only responsible for the respective segmentation (biology), body segment) of the ventral nerve cord, vertebrate brains develop axially from the midline dorsal nerve cord as a brain vesicle, vesicular enlargement at the rostral (anatomical term), rostral end of the neural tube, with centralized control over all body segments. All vertebr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Pattern Generator
Central pattern generators (CPGs) are self-organizing biological neural circuits that produce rhythmic outputs in the absence of rhythmic input. They are the source of the tightly-coupled patterns of neural activity that drive rhythmic and stereotyped motor behaviors like walking, swimming, breathing, or chewing. The ability to function without input from higher brain areas still requires modulatory inputs, and their outputs are not fixed. Flexibility in response to sensory input is a fundamental quality of CPG-driven behavior. To be classified as a rhythmic generator, a CPG requires: # "two or more processes that interact such that each process sequentially increases and decreases, and # that, as a result of this interaction, the system repeatedly returns to its starting condition." CPGs are found in humans and most other vertebrates, and in some invertebrates. Physiology CPG neurons CPG neurons can have different intrinsic membrane properties (see schematic). Some neurons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stretch Reflex
The stretch reflex (myotatic reflex), or more accurately ''muscle stretch reflex'', is a muscle contraction in response to stretching a muscle. The function of the reflex is generally thought to be maintaining the muscle at a constant length but the response is often coordinated across multiple muscles and even joints. The older term ''deep tendon reflex'' is now criticized as misleading. Tendons have little to do with the response, and some muscles with stretch reflexes have no tendons. Rather, muscle spindles detect a stretch and convey the information to the central nervous system. As an example of a spinal reflex, it results in a fast response that involves an afferent signal into the spinal cord and an efferent signal out to the muscle. The stretch reflex can be a monosynaptic reflex which provides automatic regulation of skeletal muscle length, whereby the signal entering the spinal cord arises from a change in muscle length or velocity. It can also include a polysynaptic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal cord is hollow and contains a structure called the central canal, which contains cerebrospinal fluid. The spinal cord is also covered by meninges and enclosed by the neural arches. Together, the brain and spinal cord make up the central nervous system. In humans, the spinal cord is a continuation of the brainstem and anatomically begins at the occipital bone, passing out of the foramen magnum and then enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae, where it tapers to become the cauda equina. The enclosing bony vertebral column protects the relatively shorter spinal cord. It is around long in adult men and around long in adult women. The diam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Binding
Neural binding is the neuroscientific aspect of what is commonly known as the binding problem: the interdisciplinary difficulty of creating a comprehensive and verifiable model for the unity of consciousness. "Binding" refers to the integration of highly diverse neural information in the forming of one's cohesive experience. The neural binding hypothesis states that neural signals are paired through synchronized Neural oscillation, oscillations of neuronal activity that combine and recombine to allow for a wide variety of responses to context-dependent stimulus (physiology), stimuli. These dynamic biological neural networks, neural networks are thought to account for the flexibility and nuanced response of the brain to various situations. The coupling of these networks is transient, on the order of milliseconds, and allows for rapid activity. A viable mechanism for this phenomenon must address (1) the difficulties of reconciling the global nature of the participating (exogenous) sig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuronal Oscillations
Neural oscillations, or brainwaves, are rhythmic or repetitive patterns of neural activity in the central nervous system. Neural tissue can generate oscillatory activity in many ways, driven either by mechanisms within individual neurons or by interactions between neurons. In individual neurons, oscillations can appear either as oscillations in membrane potential or as rhythmic patterns of action potentials, which then produce oscillatory activation of post-synaptic neurons. At the level of neural ensembles, synchronized activity of large numbers of neurons can give rise to macroscopic oscillations, which can be observed in an electroencephalogram. Oscillatory activity in groups of neurons generally arises from feedback connections between the neurons that result in the synchronization of their firing patterns. The interaction between neurons can give rise to oscillations at a different frequency than the firing frequency of individual neurons. A well-known example of macros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
