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Showing posts with label science. Show all posts
Showing posts with label science. Show all posts

Wednesday, May 20, 2020

Dynamic stimulation of the visual cortex allows blind and sighted people to 'see' shapes

Dynamic stimulation of the visual cortex allows blind and sighted people to 'see' shapes


For most adults who lose their vision, blindness results from damage to the eyes or optic nerve while the brain remains intact. For decades, researchers have proposed developing a device that could restore sight by bypassing damaged eyes and delivering visual information from a camera directly to the brain. In a paper publishing in the journal Cell on May 14, a team of investigators at Baylor College of Medicine in Houston report that they are one step closer to this goal. They describe an approach in which implanted electrodes are stimulated in a dynamic sequence, essentially "tracing" shapes on the surface of the visual cortex that participants were able to "see."
"When we used electrical stimulation to dynamically trace letters directly on patients' brains, they were able to 'see' the intended letter shapes and could correctly identify different letters," senior author Daniel Yoshor says. "They described seeing glowing spots or lines forming the letters, like skywriting."
Previous attempts to stimulate the visual cortex have been less successful. Earlier methods treated each electrode like a pixel in a visual display, stimulating many of them at the same time. Participants could detect spots of light but found it hard to discern visual objects or forms. "Rather than trying to build shapes from multiple spots of light, we traced outlines," says first author Michael Beauchamp. "Our inspiration for this was the idea of tracing a letter in the palm of someone's hand."
The investigators tested the approach in four sighted people who had electrodes implanted in their brains to monitor epilepsy and two blind people who had electrodes implanted over their visual cortex as part of a study of a visual cortical prosthetic device. Stimulation of multiple electrodes in sequences produced perceptions of shapes that subjects were able to correctly identify as specific letters.
The approach, the researchers say, demonstrates that it could be possible for blind people to regain the ability to detect and recognize visual forms by using technology that inputs visual information directly into the brain, should they wish to. The researchers note, however, that several obstacles must be overcome before this technology could be implemented in clinical practice.
"The primary visual cortex, where the electrodes were implanted, contains half a billion neurons. In this study we stimulated only a small fraction of these neurons with a handful of electrodes," Beauchamp says. "An important next step will be to work with neuroengineers to develop electrode arrays with thousands of electrodes, allowing us to stimulate more precisely. Together with new hardware, improved stimulation algorithms will help realize the dream of delivering useful visual information to blind people."

Story Source:
Materials provided by Cell PressNote: Content may be edited for style and length.

Journal Reference:
  1. Michael S. Beauchamp, Denise Oswalt, Ping Sun, Brett L. Foster, John F. Magnotti, Soroush Niketeghad, Nader Pouratian, William H. Bosking, Daniel Yoshor. Dynamic Stimulation of Visual Cortex Produces Form Vision in Sighted and Blind HumansCell, 2020; 181 (4): 774 DOI: 10.1016/j.cell.2020.04.033

Saturday, January 4, 2020

The Science of Sleep: A Brief Guide on How to Sleep Better Every Night

If you want to learn how to sleep better, then you're in the right place. This guide will walk you through everything you need to know if you want to get better sleep. I'll explain the science of sleep and how it works, discuss why many people suffer from sleep deprivation without knowing it, and offer practical tips for getting better sleep and having more energy.
Plain and simple, the purpose of this guide is to explain the science of how to sleep better. You can click the links below to jump to a particular section or simply scroll down to read everything. At the end of this page, you’ll find a complete list of all the articles I have written on sleep.

I. The Science of Sleep

Sleep is one of the strangest things we do each day. The average adult will spend 36 percent of his or her life asleep. For one-third of our time on earth, we transition from the vibrant, thoughtful, active organisms we are during the day and power down into a quiet state of hibernation.
But what is sleep, exactly? Why is it so important and so restorative for our bodies and minds? How does it impact our lives when we are awake?

The Purpose of Sleep

Sleep serves multiple purposes that are essential to your brain and body. Let's break down some of the most important ones.
The first purpose of sleep is restoration. Every day, your brain accumulates metabolic waste as it goes about its normal neural activities. While this is completely normal, too much accumulation of these waste products has been linked to neurological disorders such as Alzheimer's disease.
Alright, so how do we get rid of metabolic waste? Recent research has suggested that sleep plays a crucial role in cleaning out the brain each night. While these toxins can be flushed out during waking hours, researchers have found that clearance during sleep is as much as two-fold faster than during waking hours.
The way this process occurs is fairly remarkable:
During sleep, brain cells actually shrink by 60 percent, allowing the brain's waste-removal system—called the glymphatic system—to essentially “take out the trash” more easily. The result? Your brain is restored during sleep, and you wake up refreshed and with a clear mind.
The second purpose of sleep is memory consolidation. Sleep is crucial for memory consolidation, which is the process that maintains and strengthens your long-term memories. Insufficient or fragmented sleep can hamper your ability to form both concrete memories (facts and figures) and emotional memories.
Finally, sleep is paramount for metabolic health. Studies have shown that when you sleep 5.5 hours per night instead of 8.5 hours per night, a lower proportion of the energy you burn comes from fat, while more comes from carbohydrate and protein. This can predispose you to fat gain and muscle loss. Additionally, insufficient sleep or abnormal sleep cycles can lead to insulin insensitivity and metabolic syndrome, increasing your risk of diabetes and heart disease.

Tuesday, May 14, 2019

Amazing Human brain!

The human brain is the command center for the
 human nervous system. It receives signals from
 the body's sensory organs and outputs information
 to the muscles. The human brain has the same
 basic structure as other mammal brainsbut is larger
 in relation to body size than any other brains.


What are the five main functions of the brain?
Your brain contains billions of nerve cells 
arranged in patterns that coordinate thought, 
emotion, behavior, movement and sensation. 
While all the parts of yourbrain work together, 
each part is responsible for a specific function 
controlling everything from your heart rate to 
your mood.


The above said the information was very small.
In actual study of the human brain is still not finished,
and research on the human brain is never ending for now.