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By significantly increasing the speed of functional MRI (fMRI), researchers funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) have been able to image rapidly fluctuating brain activity during human thought. 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 realizing a central goal of neuroscience research: mapping the brain networks responsible for human cognitive functions such as perception, attention, and awareness.
[...] Combining several new techniques, Jonathan R. Polimeni, Ph.D., senior author of the study, and his colleagues at Harvard's Athinoula A. Martinos Center for Biomedical Imaging, 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 results of this groundbreaking work are reported in the October 2016 issue of the Proceedings of the National Academy of Sciences.
(Score: 0) by Anonymous Coward on Sunday December 04 2016, @07:18PM
According to the abstract, formerly fMRI was limited to 0.2 Hz (5 seconds per cycle). With this improved system they are now at 0.75 Hz (or 1.33_ seconds per cycle). A useful improvement, but far from what is needed to produce the results they are claiming, imo.
No way to be sure(grin), but I certainly think that I'm thinking a *lot* faster than that. No idea what speed brains operate at (anyone help out here?) Human reaction times, from sensation, through processing and finally to a motor/muscle response are often quoted at 2 Hz with elite athletes pushing on 5 Hz.
A 5 Hz reaction was recorded on Ayrton Senna, making a very quick steering correction in his Formula 1 car to prevent it from spinning -- the in-car data recording showed the time from the increase in yaw rate (rate of turn) to his pulse in the steering wheel angle.
(Score: 2) by wonkey_monkey on Sunday December 04 2016, @08:43PM
Hz is cycles per second - it doesn't really apply to reaction times, which are just a single measure of time. I assume 2Hz is meant to be 0.5s and 5Hz is meant to be 0.2s.
I just tried an online reaction test and easily got 0.33s (3Hz, if you like). So 0.2s (your 5Hz) for someone who's triained for it hardly seems crazy.
systemd is Roko's Basilisk
(Score: 2) by darkfeline on Sunday December 04 2016, @10:24PM
I doubt those 5 Hz reactions are going through the brain proper. They're probably trained reflexes, going straight through the brain stem (disclaimer, I am not a neurologist).
"Real" thought is slow, I think 1 Hz is generally good enough to recognize important stages of thought (again, armchair science).
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(Score: 0) by Anonymous Coward on Monday December 05 2016, @12:23AM
They are not measuring any "activity" in the brain, they are measuring blood!
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.
Maybe blood chemistry "associated" with brain functions, maybe not. As Buckaroo Banzai said, "When you're this far into the brain, it's all the same."
(Score: 2) by mhajicek on Monday December 05 2016, @06:32AM
"Beta wave, or beta rhythm, is the term used to designate the frequency range of human brain activity between 12.5 and 30 Hz (12.5 to 30 transitions or cycles per second)."
https://en.wikipedia.org/wiki/Beta_wave [wikipedia.org]
My first computer tan at 4.7 MHz, so I think we'll get there in my lifetime.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek