RC circuit A resistor–capacitor circuit (RC circuit), or RC filter or RC network, is an electric circuit composed of resistors and capacitors driven by a voltage or current source. A first order RC circuit is composed of one resistor and one capacitor and is the simplest type of RC circuit. RC circuits can be used to filter a signal by blocking certain frequencies and passing others. The two most common RC filters are the high-pass filters and low-pass filters; band-pass filters and band-stop filters usually require RLC filters, though crude ones can be made with RC filters. Introduction[edit] There are three basic, linear passive lumped analog circuit components: the resistor (R), the capacitor (C), and the inductor (L). This article relies on knowledge of the complex impedance representation of capacitors and on knowledge of the frequency domain representation of signals. Natural response[edit] The simplest RC circuit is a capacitor and a resistor in series. Complex impedance[edit] where and As or . per
Neurons, Synapses, Action Potentials, and Neurotransmission - The Mind Project Return to MODULE PAGE Neurons, Synapses, Action Potentials, and Neurotransmission Robert Stufflebeam: Author, Artist & Animator Functions of Neurons The central nervous system [CNS] is composed entirely of two kinds of specialized cells: neurons and glia. Hence, every information processing system in the CNS is composed of neurons and glia; so too are the networks that compose the systems (and the maps). Neurons are the basic information processing structures in the CNS. While we are considering numbers, it is worth noting that there are as many as 50 times more glia than neurons in our CNS! Because our main interest lies in exploring how information processing occurs in the brain, we are going to ignore glia. Structure of neurons A "typical" neuron has four distinct parts (or regions). Neuronal signaling Conduction To begin conduction, an action potential is generated near the cell body portion of the axon. Neurotransmission Chemical neurotransmission occurs at chemical synapses.
Kirchhoff's circuit laws Both of Kirchhoff's laws can be understood as corollaries of the Maxwell equations in the low-frequency limit. They are accurate for DC circuits, and for AC circuits at frequencies where the wavelengths of electromagnetic radiation are very large compared to the circuits. Kirchhoff's current law (KCL)[edit] The current entering any junction is equal to the current leaving that junction. i2 + i3 = i1 + i4 This law is also called Kirchhoff's first law, Kirchhoff's point rule, or Kirchhoff's junction rule (or nodal rule). The principle of conservation of electric charge implies that: The algebraic sum of currents in a network of conductors meeting at a point is zero. Recalling that current is a signed (positive or negative) quantity reflecting direction towards or away from a node, this principle can be stated as: n is the total number of branches with currents flowing towards or away from the node. This formula is valid for complex currents: Uses[edit] Kirchhoff's voltage law (KVL)[edit] Assuming
THE BRAIN FROM TOP TO BOTTOM A presynaptic neuron has several specialized structures that distinguish it from a postsynaptic neuron. The terminal button of the presynaptic neuron’s axon contains mitochondria as well as microtubules that transport the neurotransmitters from the cell body (where they are produced) to the tip of the axon. (click on 2. Axonal Transport) This terminal button also contains spherical vesicles filled with neurotransmitters. These neurotransmitters are secreted into the synaptic gap by a process called exocytosis, in which the vesicles’ membranes fuse with that of the presynaptic button. The synaptic gap that the neurotransmitters have to cross is very narrow–on the order of 0.02 micron. Across the gap, the neurotransmitters bind to membrane receptors: large proteins anchored in the cell membrane of the post-synaptic neuron.
Ohm's law V, I, and R, the parameters of Ohm's law. where I is the current through the conductor in units of amperes, V is the potential difference measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current.[3] The law was named after the German physicist Georg Ohm, who, in a treatise published in 1827, described measurements of applied voltage and current through simple electrical circuits containing various lengths of wire. In physics, the term Ohm's law is also used to refer to various generalizations of the law originally formulated by Ohm. where J is the current density at a given location in a resistive material, E is the electric field at that location, and σ is a material dependent parameter called the conductivity. History Ohm's law was probably the most important of the early quantitative descriptions of the physics of electricity. Scope
The art of mindreading: Empathy or rational inference? The ability to infer what another person is thinking is an essential tool for social interaction and is known by neuroscientists as "Theory of Mind" (ToM), but how does the brain actually allow us to do this? We are able to rationally infer what someone knows, thinks, or intends, but we are also able to "slip into their shoes" and infer how they feel, and it seems that the brain processes these different types of information in different ways, as confirmed by a new report in the June 2010 issue of Elsevier's Cortex. Prof. Elke Kalbe and colleagues from the Institute of Neuroscience and Medicine at the Research Centre Juelich and the Neurological University Clinic Cologne, Germany, studied a group of male volunteers as they performed a computerized task, which assessed their abilities in both emotional and rational inference. Coauthor Prof.
Mind-controlled quadcopter takes to the air (Screenshot by Michelle Starr/CNET Australia) Researchers at the University of Minnesota have designed an interface that allows humans to control a robot using only their thoughts. How close are we getting to actual brain control? It's starting to seem not far off at all. On the more silly end of the spectrum, we've seen robotic ears and tails that respond to brainwaves; but we've also seen more recently a Chilean company that has created a brain interface for designing printable objects, a mind-controlled exoskeleton for helping people walk, even mind-to-mind communication. A team of researchers at the University of Minnesota has just added another exciting new technology to the list: a quadcopter that can perform feats of aerial agility, controlled entirely by the pilot's thoughts. Using electroencephalography (EEG), a non-invasive cap fitted with 64 electrodes reads the electrical impulses of the brain to control the copter. Check out how the quadcopter flies in the video below.
Social Skills and Autism - Autism and Social Skills Training Why Would a Person With Autism Need to See a Social Skills Therapist? One of the most significant problems for people on the autism spectrum is difficulty in social interaction. This difficulty is, of course, made more significant by problems with speech and language. But autism also seems to create problems with "mind reading" -- that is, with knowing what another person might be thinking. This "mind blindness" can lead even the highest-functioning person on the autism spectrum to make social blunders that cause all kinds of problems. What Exactly IS a Social Skills Therapist? As autism spectrum disorders have become more and more common, a sort of industry has grown up around teaching social skills to both children and adults. In general, social skills therapists are social workers, psychologists, occupational therapists and speech/language therapists who specialize in working with autistic people. What Do Social Skills Therapists Do for People with Autism?
Green Fluorescent Protein - Cool Uses - Brainbow Brainbow Never before has a brain been so beautiful. Jeff Lichtman and Joshua Sanes, researchers at the Harvard Brain Center, have created transgenic mice with fluorescent multicolored neurons. The mice created by a genetic strategy termed "brainbow" will have a similar effect on neuroscience as Google Earth had on cartography. In the Brainbow mice, the Harvard researchers have introduced genetic machinery that randomly mixes green, cyan and yellow fluorescent proteins in individual neurons thereby creating a palette of ninety distinctive hues and colors. I can't wait for a three dimensional multicolored atlas of the brain or a Google Brain site that is as beautiful as it is useful. This is a photograph of the cerebral cortex. Another image of the cerebral cortex, which plays an important role in memory, perceptual awareness, thought and language.
Asperger Relationships There is hope for Asperger relationships. Source Are Asperger relationships difficult to maintain? The social skill and communication issues inherent in Asperger's syndrome can challenge some relationships. However, there are ways for both the person with Aspergers and loved ones to successfully work through the issues. Common Asperger Relationship Issues A person with Aspergers and his loved ones may find themselves in conflicts that have root in key aspects of the condition. Emotional Response A person with Aspergers has problems understanding another person's emotions. Sometimes a neurotypical person may mistakenly interpret a person with Aspergers' emotional response or lack of response as an inability to feel emotion. Communication and Social Skills Problems Asperger's syndrome causes problems with language, communication and social interaction. Routines and Obsessive Behaviors Routines and obsessive behaviors are aspects of Aspergers that can also challenge relationships.
Human Connectome Project | Mapping the human brain connectivity What Everybody Ought to Know About Aspergers and Marriage couple in love, by pedrosimoes on Flickr Creative Commons Young love. It's so beautiful, so wonderful, it takes your breath away. Like any other romantic couple, two adults who are in love in an Asperger's relationship are on cloud nine when they first meet. Reality sinks in once the emotional high wears off, and if there are not some tools for navigating the journey, Aspie-NT couples may find themselves at-risk. There are many successful Aspie-Aspie marriages and Aspie-NT marriages. For every successful Aspie-NT committed relationship, there are many others who are struggling, teetering, and on the brink of failing. I am borrowing the ideas for this article from Solutions for Adults with Asperger Syndrome (2005), and specifically to psychologist Dr. Building Understanding Between AS and NT Worlds Here are some autism spectrum facts about individuals with Aspergers that it's important for NT partners to understand: Steps to Help Make An AS-NT Relationship Work Here's a quote from the site:
Connectome: How the Brain's Wiring Makes Us Who We Are: Sebastian Seung: 9780547678597: Amazon.com