Social Media Sidebar

Announcement

Please sign up, comment on articles and bring your friends!

Current poll

PlanetTech is asking:

What do you think about our new web site?

Love it, indeed
Really good solution
Same as old one
The old one was better
This is a new option

Quote of the day

We've arranged a civilization in which most crucial elements profoundly depend on science and technology.

 

Carl Sagan

 

How Neuroscientists Observe Brains Watching Movies

RATE THIS! +11
Posted in Science on 31st Dec, 2012 08:11 PM by AlexMuller

Unless you have been deaf and blind to the world over the past decade, you know that functional magnetic resonance brain imaging (fMRI) can look inside the skull of volunteers lying still inside the claustrophobic, coffinlike confines of a loud, banging magnetic scanner. The technique relies on a fortuitous property of the blood supply to reveal regional activity. Active synapses and neurons consume power and therefore need more oxygen, which is delivered by the hemoglobin molecules inside the circulating red blood cells. When these molecules give off their oxygen to the surrounding tissue, they not only change color—from arterial red to venous blue—but also turn slightly magnetic.

 

Activity in neural tissue causes an increase in the volume and flow of fresh blood. This change in the blood supply, called the hemodynamic signal, is tracked by sending radio waves into the skull and carefully listening to their return echoes. FMRI does not directly measure synaptic and neuronal activity, which occurs over the course of milliseconds; instead it uses a relatively sluggish proxy—changes in the blood supply—that rises and falls in seconds. The spatial resolution of fMRI is currently limited to a volume element (voxel) the size of a pea, encompassing about one million nerve cells.



Read original article » Back to category

Comments



 

Recent headlines

  • Posted in Hardware on 2016-06-28 14:45:44
    China successfully launched new Long March 7, to be used.....read more
    Posted in Business on 2016-06-28 14:29:54
    Oculus lifts headset game restrictions..read more
    Posted in Science on 2016-06-28 14:09:49
    Ancient Mars Was Even More Earth-Like Than We Imagined..read more
    Posted in Science on 2016-06-28 13:47:31
    Artificial synapse said to rival biological synapses in.....read more
    Posted in Hardware on 2016-06-27 14:59:21
    Former NASA ISS manager planning commercial space station.....read more
Posted in Business on 2013-10-10 01:33
China is working towards a manned lunar mission in about.....read more
Posted in Business on 2013-10-20 07:17
Spacex says China is their main competitor for commercial.....read more
Posted in Software on 2013-10-20 06:43
Pirate Bay Browser Clocks 1,000,000 Downloads..read more
Posted in Medicine on 2013-10-10 02:10
Google reportedly investing hundreds of millions into new.....read more
Posted in Medicine on 2013-10-14 03:13
Endothelial Cells Can Repair and Regenerate Organs,.....read more
Posted in Science on 01.01.2010
Spacex says China is their main competitor for commercial.....read more
Posted in Science on 01.01.2010
Staring at Your Phone Could Be Making You Short Sighted..read more
Posted in Science on 01.01.2010
Oculus Rift virtual reality headset coming to mobile, but.....read more
Posted in Science on 01.01.2010
China is working towards a manned lunar mission in about.....read more
Posted in Science on 01.01.2010
Delivering drugs via nanoparticles to target mitochondria..read more

Recent Blog Posts

  • Posted by AlexMuller
    'Flower Power': Photovoltaic cells replicate rose petals..read more
    Posted by AlexMuller
    Probing giant planets' dark hydrogen..read more
    Posted by AlexMuller
    Nanoscientists develop the 'ultimate discovery tool'..read more
    Posted by AlexMuller
    Small brain, astounding performance: How elephantnose fish.....read more
    Posted by AlexMuller
    Giant Blobs of Rock, Deep Inside the Earth, Hold Important.....read more

Login to your Account

Login to your PlanetTech Account here

Username:
Password:
Remember me
or

Create a New Account

You just need username and password

The following errors occured:
Username:
Email:
Password:
Verify password:
Remember me