Neuron All neurons are electrically excitable, maintaining voltage gradients across their membranes by means of metabolically driven ion pumps, which combine with ion channels embedded in the membrane to generate intracellular-versus-extracellular concentration differences of ions such as sodium, potassium, chloride, and calcium. Changes in the cross-membrane voltage can alter the function of voltage-dependent ion channels. If the voltage changes by a large enough amount, an all-or-none electrochemical pulse called an action potential is generated, which travels rapidly along the cell's axon, and activates synaptic connections with other cells when it arrives. Neurons do not undergo cell division. In most cases, neurons are generated by special types of stem cells.
Diffusion MRI Diffusion MRI (or dMRI) is a magnetic resonance imaging (MRI) method which came into existence in the mid-1980s. It allows the mapping of the diffusion process of molecules, mainly water, in biological tissues, in vivo and non-invasively. Molecular diffusion in tissues is not free, but reflects interactions with many obstacles, such as macromolecules, fibers, membranes, etc. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. Functional magnetic resonance imaging Researcher checking fMRI images Functional magnetic resonance imaging or functional MRI (fMRI) is a functional neuroimaging procedure using MRI technology that measures brain activity by detecting associated changes in blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases.
10 Websites that Teach Coding and More So you want to learn to code, do you? Well, you happen to be in luck, as it has never been easier or cheaper to learn that new skill, and there are plenty of websites that teach coding and more. They will help turn you from zero to hero, as long as you stick to it and practice, practice, practice! Making Sense of the World, Several Senses at a Time Our five senses–sight, hearing, touch, taste and smell–seem to operate independently, as five distinct modes of perceiving the world. In reality, however, they collaborate closely to enable the mind to better understand its surroundings. We can become aware of this collaboration under special circumstances. In some cases, a sense may covertly influence the one we think is dominant.
Electroencephalography Simultaneous video and EEG recording of two guitarists improvising. Electroencephalography (EEG) is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain. In clinical contexts, EEG refers to the recording of the brain's spontaneous electrical activity over a short period of time, usually 20–40 minutes, as recorded from multiple electrodes placed on the scalp. Diagnostic applications generally focus on the spectral content of EEG, that is, the type of neural oscillations that can be observed in EEG signals. Diffusion MRI Diffusion MRI (or dMRI) is a magnetic resonance imaging (MRI) method which came into existence in the mid-1980s. It allows the mapping of the diffusion process of molecules, mainly water, in biological tissues, in vivo and non-invasively. Molecular diffusion in tissues is not free, but reflects interactions with many obstacles, such as macromolecules, fibers, membranes, etc. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. The first diffusion MRI images of the normal and diseased brain were made public in 1985. Since then, diffusion MRI, also referred to as diffusion tensor imaging or DTI (see section below) has been extraordinarily successful. Its main clinical application has been in the study and treatment of neurological disorders, especially for the management of patients with acute stroke.
Read page 99s & give feedback Why Page 99, Not Page 1? Because it's arbitrary. It's rarely as worked on as the elements we usually judge a book by. Like the synopsis, the first few pages, or (you know it's true) the cover. The Brain: A Body Fit for a Freaky-Big Brain Aiello and Wheeler noted that this dramatic increase in brain size would seem to have required a dramatic increase in metabolism—the same way that adding an air-conditioning system to a house would increase the electricity bill. Yet humans burn the same number of calories, scaled to size, as other primates. Somehow, Aiello and Wheeler argued, our ancestors found a way to balance their energy budget. As they expanded their brains, perhaps they slimmed down other organs.
100 Exquisite Adjectives By Mark Nichol Adjectives — descriptive words that modify nouns — often come under fire for their cluttering quality, but often it’s quality, not quantity, that is the issue. Plenty of tired adjectives are available to spoil a good sentence, but when you find just the right word for the job, enrichment ensues. Practice precision when you select words. Here’s a list of adjectives: Subscribe to Receive our Articles and Exercises via Email The Secrets of Your Brain's Zoom Lens Notice that, even as you fixate on the screen in front of you, you can still shift your attention to different regions in your peripheries. For decades, cognitive scientists have conceptualized attention as akin to a shifting spotlight that “illuminates” regions it shines upon, or as a zoom lens, focusing on things so that we see them in finer detail. These metaphors are commonplace because they capture the intuition that attention illuminates or sharpens things, and thus, enhances our perception of them. Some of the important early studies to directly confirm this intuition were conducted by NYU psychologist Marisa Carrasco and colleagues, who showed that attention enhances the perceived sharpness of attended patterns.
How to plan a round-the-world trip - travel tips and articles Itʼs the ultimate trip: circumnavigating the planet, and stopping off wherever takes your fancy. Great for travellers who want to see it all, or who are just plain indecisive. But booking a round-the-world (RTW) trip can be a complex business. Hereʼs our guide to getting started. How to do it The most economical way to circumnavigate is to buy a round-the-world air ticket that uses one airline alliance.
How mapping neurons could reveal how experiences affect mental wiring This article was taken from the July 2012 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online. No road, no trail can penetrate this forest. The long and delicate branches of its trees lie everywhere, choking space with their exuberant growth. No sunbeam can fly a path tortuous enough to navigate the narrow spaces between these entangled branches. The Brain's Highways: Mapping the Last Frontier Frontiers are in short supply. No explorer will again catch that first glimpse of the Pacific Ocean with “wild surmise,” take the first steps on the moon, or arrive first at the Challenger deep – the remotest corners of the earth are now tourist attractions. Even in science, great mysteries have fallen – life itself has gone from being the subject of metaphysical speculation about vital substances to the biophysical understanding of cellular processes. Uncharted territories, both physical and metaphorical, are hard to find.