Love the progress in brain imaging. Similar to fMRI, this seems to be focused on identifying blood flow to different areas which seems useful for a lot of diagnostic/medical purposes. I’m personally doubtful that the use cases at the end of the article like brain-computer interfaces are well-suited to the technology though, since it can’t measure neural activity as directly as electrodes.
One thing it doesn’t discuss is the latency of the observed signals relative to brain activity — in MRI there is a 5-6 second delay due to the time it takes for brain activity to translate into blood flow and oxygen signals, whereas electrical activity is in real time.
As a dental professional working with oral/maxillofacial surgery teams, I can’t wait for fMRI quality imaging in a portable affordable device. First to market with such systems will make a fortune.
Having just had a wisdom tooth extracted, something that can help them locate nerves for targeted local anesthesia would be nice. In both this and a crown procedure I had done ten years ago the needle hit a nerve bundle and it felt like my face was getting tazed lol.
I guess fMRI isn’t really a good analog. What is needed is an MRI quality video sequence showing movement. Dynamic planning would allow occlusal schemes to be designed more accurately, therefore avoiding many common issues with full arch rehab, for example.
What are the disadvantages to this method in comparison to traditional CT/MRI scans?
The only negative mentioned was the sheer amount of data produced (they didn't say anything about processing that data into an image which I assume is also taxing). The necessity of a contrast agent is also an (insignificant, comparatively, but worth mentioning) limitation
My favorite somewhat related research is using focused high energy ultrasound with microbubbles to open the blood-brain barrier enough to allow therapeutics to pass through. Ultrasound is an old technique that sort of went out of style but it truly is lot of fun.
I appreciate that the article is written to be readable to a wide audience. But:
> But ultrafast ultrasound is exponentially faster, more powerful, and more spatially sensitive than standard ultrasound: It can produce many thousands of detailed high-resolution images per second.
is there any way to stop this weird mutation of the meaning of the word "exponentially"? Probably not, I guess. I trip over it when reading: "Hmm... so it's exponential in... oh, dammit, they just mean 'way faster'."
I mean, exponents can be fractions. Maybe it's x^1.2 faster? I think it is funny when advertisements claim that something is "a fraction of the price". You could literally raise prices and run such an ad, and be technically correct. 3/2 is a fraction, after all.
The idea still holds. 0.9^x is exponential. But that aspect doesn't awaken the pedant in me; I'm willing to accept that we often assume a range of inputs.
If Gary tells me that he made twice as much at poker as Fred, I'm not going to bother considering the possibility that he lost $1000 to Fred's $500.
We're still going to need a word for "exponentially" though, and it would help if that word contained "exponent." "Terrific" is an unnecessary word in English, just because we have a ton of words for things that inspire fear.
"Exponentially" being used to mean "a lot" is bad not because it's a new usage, but because "exponentially" is being demoted to a word that has a bunch (a shitload, a fuckton, lots, plenty, too many) synonyms when in its accurate usage it's a word with few or none. You're losing meaning when you make a thing more complicated to say.
Of course, this sort of usage happens a lot, too, but it's always because some people are using a technical-sounding word to substitute for a common word in order to give the impression of expertise.*
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* as opposed to when technicians steal a common word and make it a very specific technical term, which also happens all the time.
We can go back to saying "geometrically", which was the previous term for multiplicative increase. It even has the advantage of being confusing when misused.
meh, literally. exponentially is just an intensifier applied to a comparative.
its never really unclear which is which. two objects is comparison, one object is process, as in, lily pads filled the pond exponentially. Which modifies filled not a comparative.
See, I guess I'm just on the opposite end of the pedantry scale from you, because I'm now sitting here trying to imagine what a literal meh would look like or taste like.
> exponentially is just an intensifier applied to a comparative.
That is how it is misused, yes. Used correctly, it refers to a class of functions that take a varying quantity as input. cf linearly, quadratically.
> ...lily pads filled the pond exponentially. Which modifies filled not a comparative.
I don't have a problem with that example. Well, I would prefer it to be "lily pads multiplied exponentially to fill the pond", but that's not much of a jump.
The verb "filled" suggests the input: time. "ultrafast ultrasound is exponentially faster [than traditional ultrasound]" does not. Is it exponential in the amount of power you apply? The duration of a reading? The number of goats you sacrifice?
Sure you can be prescriptive and deny the real world english speakers using a word and being understood. That's why I made the literally reference. Words change and gain meanings over time. This use is very common. To call it a misuse seems too far to me.
The context of uses is almost always entirely disjoint as well. Compare:
Covid cases are growing exponentially, we need to do something. (covid spreads in proportion to number of infected)
Twitter is growing exponentially, I must invest! (network effects are causing something to accelerate, but obviously users don't create new users, nor do tweets create tweets)
My love for you grows exponentially day by day, let's get married! (basic intensifier)
I would guess these sentences are in descending order of acceptability for you.
Heh. I suspect we could argue this all day, partly because there is very little we're actually disagreeing on, and I suspect much that we do agree on (or at least, I find your arguments well-stated and have upvoted accordingly, and mostly agree with them.)
As I said in my original post, I doubt there's a way of halting the shift in meaning in real-world usage. I just find that it impoverishes the word and degrades the ability to express something that is worth expressing.
I don't, in fact, have any problem with any of your three examples. The Twitter one is the most problematic, but it still works because I disagree with "users don't create new users"—they kind of do: if 10% of users convince one friend to join, then you have exponential growth. If size were proportional to the network effects, which are quadratic, then the statement would bother me. And it might be, for all I know, but given that (1) there's a decent argument for it being exponential and (2) it's not like there's that big of a difference between a quadratic curve and an exponential curve bounded at the very least by the world population, well... I guess I'm not that pedantic!
As for the 3rd sentence, what kind of jerk would I be to reject such a warm and honest expression of your love? ;-) More seriously, once something is figurative then keeping the original meaning of exponential enhances the declaration—there's a subtle implication that love produces love.
One thing it doesn’t discuss is the latency of the observed signals relative to brain activity — in MRI there is a 5-6 second delay due to the time it takes for brain activity to translate into blood flow and oxygen signals, whereas electrical activity is in real time.