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Learning Engineering Applies the Learning Sciences
Published in Jim Goodell, Janet Kolodner, Learning Engineering Toolkit, 2023
Jim Goodell, Janet Kolodner, Aaron Kessler
We previously discussed how the brain is wired and how learning, in a sense, rewires your brain. Neuroplasticity, also known as brain plasticity or neural plasticity, is the ability of the brain to change throughout an individual’s life.30 At the single cell level, synaptic plasticity 31 refers to changes in the connections between neurons, whereas non-synaptic plasticity 32 refers to changes in their intrinsic excitability, for example, how responsive they are to the chemical signals they receive.33 The structure of the brain can change throughout life but may be more “plastic” during developmental periods from prenatal to early 20s. For more detailed explanations of what researchers have discovered about changes that occur with age and learning across the life span, see How People Learn II. 34
Neural Network Survival Analysis
Published in Prabhanjan Narayanachar Tattar, H. J. Vaman, Survival Analysis, 2022
Prabhanjan Narayanachar Tattar, H. J. Vaman
The setup of neurons in the brain as seen in Figure 10.1, reproduced from Figure 2 of Haykin (2009)[52] has inspired the architecture of neural networks. The figure is an illustration of the shape of pyramidal cell which is one of the common types of cortical neurons. The cortical neuron receives the input through dendritic spines. The cell receives more than 1e5 synaptic contacts and it can further project onto thousands of target cells. Most of the neurons pass on their output through a series of brief voltage pulses/action potentials/spikes. The spikes originate closer to the cell body of neurons and then propagate across the individual neurons at almost constant velocity and amplitude. The use of action potentials as communication between the neurons is based on the physics of axon which is very long and thin and characterized by high electrical resistance and large capacitance. This description is adapted from Haykin (2009)[52].
Yangsheng in the twenty-first century
Published in Vivienne Lo, Michael Stanley-Baker, Dolly Yang, Routledge Handbook of Chinese Medicine, 2022
This raises a further key issue in the nature of yangsheng practices; the plasticity of the human brain. Neuroplasticity in the brain is a well-observed phenomenon. It is described thus: The brain’s ability to reorganize itself by forming new neural connections throughout life. Neuroplasticity allows the neurons (nerve cells) in the brain to compensate for injury and disease and to adjust their activities in response to new situations or to changes in their environment.Shiel (2017)
Efficient simulations of stretch growth axon based on improved HH model
Published in Neurological Research, 2023
Xiao Li, Xianxin Dong, Xikai Tu, Hailong Huang
Neuronal cell is composed of three components: a cell body, an axon, and a dendrite. These components are responsible for receiving, integrating, and delivering information. In general, neurons receive and integrate information from other neurons via their dendrites and cell bodies, and then transfer it to other neurons via their axons. Nerve fibers have great excitability and conductivity, and their primary role is to transmit information between neurons. When a sufficient stimulus excites a nerve fiber, it immediately generates a propagable action potential. Chemical synapses allow action potentials to be passed from one neuron to the next by transporting neurotransmitters through synaptic vesicles. The action potential-induced shift in membrane potential causes the calcium channel on the synaptic terminal membrane to open, allowing a substantial number of calcium ions to flow into the membrane, resulting in an abrupt increase in calcium ions in the synaptic membrane. When synaptic vesicles detect an increase in the number of calcium ions in the surrounding environment, they fuse with the presynaptic membrane and spit neurotransmitters into the synaptic gap. After binding to a protein receptor on the postsynaptic membrane, the neurotransmitter causes excitement or inhibition.
Prediction of abrasive wears behavior of dental composites using an artificial neural network
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Abhijeet Shivaji Suryawanshi, Niranjana Behera
The human brain is composed of billions of interconnected neurons by an unbelievable number of connections. Each neuron is linked to several other neurons and communicates with them regularly. So any physical or mental activity, we engage in activates a certain group of neurons in our brains. Figure 1(a) describes the structure of neuron in a brain. A single neuron is made up of three parts: (1) dendrites, (2) cell body, and (3) terminals. An artificial neuron, seen in Figure 1(b), is a computational and mathematical model of a biological neuron. Figure 1(c) shows the architecture of a neural network having input p, output a, and feeding with r and s parameters. Other parameters of a neural network are bias vector b, weight matrices w, transfer function f, and linear combiner u (Maleki and Unal 2021).
The neurosciences at the Max Planck Institute for Biophysical Chemistry in Göttingen
Published in Journal of the History of the Neurosciences, 2023
Synapses are the points of contact between individual neurons and mediate the signal transfer in the nervous system. The term synapse was introduced in 1897 by the British neurophysiologist and later Nobel laureate Charles Sherrington (1857–1952), long before its structure and function were clarified (Valenstein 2005, 4) and, above all, against the bitter resistance of the so-called “reticularists,” who believed that nerve cells formed a syncytium (Nissl 1903). In the first half of the last century, first the functional roles of synapses were studied—that is, the chemical signal transmission by a neurotransmitter, its quantal release, and its effect on the postsynaptic nerve cells. When electron microscopy, which had been developed from the 1930s onward, came into use in 1954 (Hentschel 2014, 311; Ruska 1955), it became possible to examine the structure of the synapses, showing that they contained large quantities of small blisters known as vesicles and that the membranes are thickened at the contact points (Figure 3; see De Robertis 1964, 27–48; Cowan and Kandel 2001, 1–87).