
Evidence that the brain’s ability to control thinking relies on beta rhythms - el_duderino
http://news.mit.edu/2018/new-study-reveals-how-brain-waves-control-working-memory-0126
======
randomdrake
Study: Gamma and beta bursts during working memory readout suggest roles in
its volitional control

Citation: Mikael Lundqvist, Pawel Herman, Melissa R. Warden, Scott L. Brincat
& Earl K. Miller. Nature Communications 9, Article number: 394 (2018).

Link:
[https://dx.doi.org/10.1038/s41467-017-02791-8](https://dx.doi.org/10.1038/s41467-017-02791-8)

DOI: 10.1038/s41467-017-02791-8

Abstract: Working memory (WM) activity is not as stationary or sustained as
previously thought. There are brief bursts of gamma (~50–120 Hz) and beta
(~20–35 Hz) oscillations, the former linked to stimulus information in
spiking. We examined these dynamics in relation to readout and control
mechanisms of WM. Monkeys held sequences of two objects in WM to match to
subsequent sequences. Changes in beta and gamma bursting suggested their
distinct roles. In anticipation of having to use an object for the match
decision, there was an increase in gamma and spiking information about that
object and reduced beta bursting. This readout signal was only seen before
relevant test objects, and was related to premotor activity. When the objects
were no longer needed, beta increased and gamma decreased together with object
spiking information. Deviations from these dynamics predicted behavioral
errors. Thus, beta could regulate gamma and the information in WM.

~~~
tomalpha
I can’t tell from this, but does this demonstrate a causal link or is the
headline somewhat disconnected from the paper?

That is to say, does the brain truly rely on beta rhythms, or are they just a
symptom of something else?

~~~
maxander
I think the answer is necessarily "no," because the rhythm is a sign we
observe of some functional system in the brain, not the functional system
itself. Similar to how your heart rate is just a sign of the beating of your
heart, only the latter of which is a real functional mechanism. Something is
happening in the brain that generates these patterns and which _also_ has to
do with the cognitive faculties described in the paper; I don't think anyone
has a very clear idea what that mechanism is, though.

I'm not sure if this answers your question, or is just pedantry. :)

~~~
anon1253
The waves come from synchronicity of neurons "firing". When neurons fire there
is a flow of ions that causes a potential difference. If a lot of this happens
at the same time with some periodicity you can measure this. But it would be
like looking at a CPU running some math operations and determining "there is
periodic activity in the ALU" (which could be due to memory reads). Now this
is a poor analogy because a single neuron doesn't do "one thing" it's
massively distributed. My go to argumentation for "how the brain works" (and
thus consciousness) has been that it's a massive coincidence detector that
tries to encode these coincidences in spike train activity using spike train
dependent plasticity. In doing so the brain echoes the coincidences of the
neural (sensory) input, and since these encode for some "real" cause-effect
you can predict the future: memory is "echoing" in a neural substrate,
consciousness is exploiting those "echos" to try to predict the future. I
wrote it up in 2011
[https://www.dropbox.com/s/huol1vf4j1fs1ll/mind_matters.pdf?d...](https://www.dropbox.com/s/huol1vf4j1fs1ll/mind_matters.pdf?dl=0)
I've never seen anyone poke holes in this, and even hints at the details of
this paper. Guess I chose the wrong career somewhere.

------
Shank
I wonder how much this can be applied to day to day life. For example, the
Binaural app on the iOS app store acts as a wave generator that lets you
listen to specific frequencies. I'd be interested to see if you could force
yourself into getting beta wave activity in the brain by just listening to
beta frequencies -- almost as if to tune yourself manually.

~~~
chc
Expecting your brain to operate in a way that produces certain frequencies
because your ears are detecting air vibrations with those frequencies sounds
extremely homeopathic.

~~~
tw1010
Dismissing it based on nothing more than a feeling, and no data, is just as
irrational as homeopaths.

~~~
tree_of_item
No it isn't. You should default to disbelieving such extraordinary claims.

~~~
tw1010
You should default to having no strong opinion at all.

~~~
chc
Skepticism due to insufficient evidence and lack of obvious plausibility isn't
usually considered a strong opinion.

~~~
colordrops
There is evidence though.

~~~
chc
Whether or not there is evidence of this particular thing is irrelevant,
because this subthread is about whether skepticism is just as irrational as
blind belief when confronted with unsupported claims.

------
hawktheslayer
I just finished reading _Wait But Why 's_ excellent article on NeuralLink
[https://waitbutwhy.com/2017/04/neuralink.html](https://waitbutwhy.com/2017/04/neuralink.html)

I wonder if these top-down beta rythmes would force out implanted data similar
to white blood cells and viruses.

------
21
> There are millions of neurons in the brain

Why would they use a different order of magnitude. Surely they know that there
are billions of them (100 bil in fact).

------
syswsi
If anyone here is interested in learning more about Neurotechnology, I co-
founded an organization called NeuroTechX which brings together
neurotechnology enthusiasts from across the world. You can find out more about
us at [http://neurotechx.com/](http://neurotechx.com/)

------
digikata
Radiolab had an interesting episode on the gamma frequency, possibly
stimulated by light or sound and a possible relation to Alzheimers.

[https://www.radiolab.org/story/bringing-gamma-
back/](https://www.radiolab.org/story/bringing-gamma-back/)

Makes one wonder about the effects of raves.

------
jnordwick
It seems almost definitional that this effect is correlative and not causative
unless the authors are positing that there are structures in the brain whose
purpose is to generate brain waves or that we just massively misunderstand the
function of neurons.

I read the previous paper summary linked to and I didn't see a way these waves
are supposed to affect the neurons. Is there absolutely any theory as to the
mechanism? Seems like bad science and reasoning even if the topic is
interesting.

~~~
tomalpha
This was my reading of the paper/summary too - a demonstration of correlation
but not the evidence of a causal link that the headline suggests.

My understanding of neuroscience is limited however. Can someone with a better
understanding point me at what I’m missing?

~~~
growlix
Your comprehension seems spot on to me, though maybe you feel like you're
missing something given the apparent discrepancy between the hype vs. value of
this research. I think there are two relevant factors here:

1) MIT is very good at publicity and press.

2) Causal neuroscience experiments are still technically challenging to
implement in complex behaving organisms (e.g. monkeys and humans). We have
methods such as microstimulation (invasive) and transcranial magnetic
stimulation (non-invasive), but these methods are pretty ham-fisted. They
indiscriminately activate (or deactivate) all the neurons in and passing
through a given volume in the brain (optogenetics is promising in this regard,
but it's still a nascent technology in monkeys). So while this study may
appear weak because it's correlational, it may actually represent a meaningful
step forward in the field.

~~~
jnordwick
Is the current thought that brainwaves affects the brain? What's the mechanism
for this? They aren't even really waves like we think of radio waves or
magnetic waves. Saying that brain waves have a "function" like a Scientific
American article seems so backwards. I'm a little confused why the language
used around them is of casuality.

------
tw1010
Is there any data about the tendency towards of beta rhythms vs not in
different cultures around the world?

~~~
andai
Since brainwaves are associated with brain disorders and brain disorders are
associated with genetics, it would be worth (albeit dangerous politically?) to
investigate the link between brainwaves (and by extension, different cognitive
faculties) and ethnicity.

~~~
jnordwick
This assumes that brainwaves function the same in everybody and that their
measurement means anything more than phrenology.

~~~
ipsum2
Do you base this claim off of any scientific evidence? Measuring schizophrenia
based off of gamma oscillations is standard clinical practice.

[https://www.ncbi.nlm.nih.gov/pubmed/27732692](https://www.ncbi.nlm.nih.gov/pubmed/27732692)

[https://www.ncbi.nlm.nih.gov/pubmed/16571550](https://www.ncbi.nlm.nih.gov/pubmed/16571550)

[https://www.nature.com/articles/npp201617.pdf?origin=ppub](https://www.nature.com/articles/npp201617.pdf?origin=ppub)

~~~
jnordwick
I didn't mean to imply they were totally useless just that too much might be
read into them. I guess i did use a bad comparison.

