Washington: Scientists have for the first time
successfully tracked human thought by imaging rapidly fluctuating brain
activity using fast fMRI.
Functional magnetic resonance imaging
(fMRI) measures changes in blood oxygenation, which were previously thought to
be too slow to detect the subtle neuronal activity associated with higher order
brain functions.
The new discovery that fast fMRI can
detect rapid brain oscillations is a significant step towards realising a
central goal of neuroscience research: mapping the brain networks responsible
for human cognitive functions such as perception, attention, and awareness.
“This work demonstrates the potential of
fMRI for mapping healthy neural networks as well as those that may contribute
to neurological diseases such as dementia and other mental health disorders,
which are significant national and global health problems,” said Guoying Liu
from the US National Institute of Biomedical Imaging and Bioengineering
(NIBIB).
The fMRI works by detecting local
increases in oxygen as blood is delivered to a working part of the brain. The
technique has been instrumental for identifying which areas in the brain
control functions such as vision, hearing, or touch.
However, standard fMRI can only detect
the blood flow coming to replenish an area of the brain several seconds after
it has performed a function.
It was generally accepted that this was
the limit of what could be detected by fMRI-identification of a region in the
brain that had responded to a large stimulus, such as a continuous 30 second
“blast” of bright light.
Combining several new techniques,
researchers applied fast fMRI in an effort to track neuronal networks that
control human thought processes, and found that they could now measure rapidly
oscillating brain activity.
The researchers used fast fMRI in human
volunteers observing a rapidly fluctuating checkerboard pattern.The fast fMRI
was able to detect the subtle and very rapid oscillations in cerebral blood
flow in the brain's visual cortex as the volunteers observed the changing
pattern. -PTI
Source: DNA-5th-December-2016
http://epaper2.dnaindia.com/index.php?pagedate=2016-12-5&edcode=820009&subcode=820009&mod=1&pgnum=2
