I hadn't actually known this, but the creator of the Dilbert cartoons, Scott Adams, was diagnosed about two years ago with a rare disease called spasmodic dysphonia. Apparently he just recovered -- in spite of overwhelming odds against that happening.
First a bit about spasmodic dysphonia. Spasmodic dysphonia is a movement disorder involving the muscles of speaking. It is characterized by spasms in the adductor and/or abductor muscles of the larynx (the adductor muscles bring the vocal cords together and the abductor muscles bring the vocal cords apart). Spasms in either muscles prevents the vocal cords from moving in a coordinated manner necessary for speaking.
The National Spasmodic Dysphonia Association has some great Real Player audio clips of what both adductor and abductor dysphonia sound like. eMedicine describes the speaking difficulties as follows:
Strained or strangled phonation and irregular voice stoppages (the form originally described and most commonly observed clinically) characterize adductor dysphonia. Abductor SD presents with a breathy or absent voice or brief vocal loss and is associated with abrupt widening of the glottis.
Unfortunately it is not known what causes spasmodic dysphonia, although genetic causes are likely. It is suspected that the problem is located in a part of the brain called the basal ganglia -- the part of the brain responsible for regulating the initiation of conscious motion. We think this partly because another movement disorder involving the basal ganglia, Parkinson's disease, results from a deficit of dopamine. Supplementation with L-Dopa (a dopamine precursor) in Parkinson's patients can result in a dramatic, if short-term, improvement. Some individuals with spasmodic dysphonia also respond to treatment with L-dopa.
The weird part about movement disorders of the basal ganglia is that because it is a problem in the initiation of motion, the effectors that actually create the motion are unaffected. This means that someone with Parkinson's disease has muscles that move and working neurons that connect to those muscles. The problem is getting those systems to activate. Similarly, in spasmodic dysphonia the individual has a functional vocal system. The issue is getting the muscles to work together appropriately. This explains some weird findings such as the observation that people with spasmodic dysphonia can often sing just fine, even if they can't talk. Also, situations of stress tend to make the symptoms worse.
Scott Adams described his symptoms like this:
As regular readers of my blog know, I lost my voice about 18 months ago. Permanently. It's something exotic called Spasmodic Dysphonia. Essentially a part of the brain that controls speech just shuts down in some people, usually after you strain your voice during a bout with allergies (in my case) or some other sort of normal laryngitis. It happens to people in my age bracket.
I asked my doctor - a specialist for this condition - how many people have ever gotten better. Answer: zero. While there's no cure, painful Botox injections through the front of the neck and into the vocal cords can stop the spasms for a few months. That weakens the muscles that otherwise spasm, but your voice is breathy and weak.
The weirdest part of this phenomenon is that speech is processed in different parts of the brain depending on the context. So people with this problem can often sing but they can't talk. In my case I could do my normal professional speaking to large crowds but I could barely whisper and grunt off stage. And most people with this condition report they have the most trouble talking on the telephone or when there is background noise. I can speak normally alone, but not around others. That makes it sound like a social anxiety problem, but it's really just a different context, because I could easily sing to those same people.
I stopped getting the Botox shots because although they allowed me to talk for a few weeks, my voice was too weak for public speaking. So at least until the fall speaking season ended, I chose to maximize my onstage voice at the expense of being able to speak in person.
He mentions that this is often treated with Botox injections. This is true, and it is basically the only treatment out there -- although surgery is being piloted. The Botox is injected into the muscles to cause them to relax. Unfortunately it is very painful and has to be done repeatedly, generally every 3-6 months.
Fortunately for Mr. Adams, it appears his symptoms have improved spontaneously:
The day before yesterday, while helping on a homework assignment, I noticed I could speak perfectly in rhyme. Rhyme was a context I hadn't considered. A poem isn't singing and it isn't regular talking. But for some reason the context is just different enough from normal speech that my brain handled it fine.
Jack be nimble, Jack be quick.
Jack jumped over the candlestick.I repeated it dozens of times, partly because I could. It was effortless, even though it was similar to regular speech. I enjoyed repeating it, hearing the sound of my own voice working almost flawlessly. I longed for that sound, and the memory of normal speech. Perhaps the rhyme took me back to my own childhood too. Or maybe it's just plain catchy. I enjoyed repeating it more than I should have. Then something happened.
My brain remapped.
My speech returned.
Not 100%, but close, like a car starting up on a cold winter night. And so I talked that night. A lot. And all the next day. A few times I felt my voice slipping away, so I repeated the nursery rhyme and tuned it back in. By the following night my voice was almost completely normal.
When I say my brain remapped, that's the best description I have. During the worst of my voice problems, I would know in advance that I couldn't get a word out. It was if I could feel the lack of connection between my brain and my vocal cords. But suddenly, yesterday, I felt the connection again. It wasn't just being able to speak, it was KNOWING how. The knowing returned.
I still don't know if this is permanent. But I do know that for one day I got to speak normally. And this is one of the happiest days of my life.
I don't know if I would describe it as rewiring; it may be that his basal ganglia simply fell back into a more permissive and less spasmodic state. However, this is still fantastic. It is really very difficult to predict whether patients like this will get better, and the prognosis generally isn't very good. I am happy that he is feeling better, and I hope it lasts.
Hat-tip: Slashdot.
- Log in to post comments
More like this
I'm HIGHLY skeptical of this so-called remapping. So me, this sounds more like someone who got over a cognitive or psychological problem rather than a neurological one. Repair to nerves, especially in the brain, happens extremely slowly exhibited by gains of function over time, rather than instantaneously. Of course, I'm very glad for him that he has recovered, but I wonder if he was ever properly diagnosed.
Shelley, I'm gonna have to (respectfully) disagree with you on at least two points. First, what cognitive or psychological problem isn't neurological? Clearly these problems don't arrive out of the ether!
Secondly, remapping in several cortical areas is really quick; receptive fields in primary visual cortex reorganize rapidly after retinal damage (see Charlie Gilbert, Rockefeller Univ.), see my post about remapping via sparse preexisting connections from somatosensory areas to visual cortex over at peripersonalspace.wordpress.com, and see my next series of posts (coming soon, I swear, as soon as I finish all this grading!) on remapping of space around the hand (that is peripersonal space) by tool use that happens very quickly.
That being said, I'm no expert on spasmodic dysphonia and I have no idea what happened in this guy. But remapping quickly by retraining your voice in some way, as Mr. Adams describes, is not out of the realm of possiblity, in my read of today's plasticity research.
Good points, Michael. I defer to your learned wisdom! :D
To be more complete, though, Shelley...there are many paths to plasticity. The way you bring up, recovery of function after CNS damage (as opposed to reorganization after deprivation or after peripheral damage) is clearly a different animal than the phenomena I was describing, and much more difficult too, as well as time-consuming and energy-hogging. So, sorry if I was too strong in my reply!
That's an incredibly sloppy use of language. Just because cognition arises from neurology does NOT mean that a cognitive problem has its roots in a neurological malfunction, and while any cognitive state is the result of a specific physical configuration, disordered processing does not imply that the physical configurations involved fall outside of normal functioning.
A glitch in the software does not imply a glitch in the hardware.
While I'm on the subject:
Perhaps a (very loose) comparison can be drawn between spasmodic dysphonia and hiccups. Hiccups usually terminate quickly, but rarely they can last for months and years - and when they do end, it is often because sufferers force breathing patterns to shift and something about the change causes the diaphragm to stop spasming. It's nowhere near a explanation, but maybe something analogous happened here. Just with neurons. And stuff.
caledonian, I don't fully get what you are saying. If I have word-finding difficulty or am in a tip-of-the-tongue state, that's a minor annoyance to be sure. But it is a cognitive state, and certainly there is a neural reason for it (activation "flowing" temporarily to the wrong "representation", which inhibits parts of the proper "representation" from "getting activated") - I'm not claiming large-scale neurological dysfunction or anything, only that all cognitve states have neural precursors.
A glitch in the software absolutely implies a glitch in the hardware! Maybe not a big or pathological glitch, I certainly didn't mean to imply that.
Your hiccup example is a good one.
I agree with MIchael and Caledonian's optimism, (though MIchael was much nicer), but I'd like to see some similar cases of recovery from this specific condition or at least something closely related.
No, no, no! That is completely wrong. All hardware glitches result in software glitches, but the reverse is not true - it is in fact very easy to induce a software glitch that doesn't have a corresponding hardware glitch.
The criteria that define what qualifies as 'functional' hardware are necessarily broader than the criteria that define 'functional' software, at least when talking about multiple-purpose machines. (Hardware can be made identical to software, but that is most certainly not what we encounter in human neurology, so I'm justified in ignoring that trivial state.) If I formatted your computer's drives, the drives wouldn't be damaged. Their physical conditions would not have passed across the conceptual boundaries we use to define their functionality. Those drives would have included specific patterns of magnetic domain orientations. Those patterns would have been erased, and the information they encoded severely damaged or destroyed, but the drive isn't damaged.
If you'd like a sophisticated yet comprehensible explanation of the difference between an emulating system and the system it emulates, I'd recommend you read Godel, Escher, Bach. Or learn something about computer programming.
Do not confuse the limitations of the program with either an error in the execution of that program or a hardware fault. They are not at all the same thing.
The distinction between "software" and "hardware" that holds for von Neumann architecture computers is simply inapplicable to nervous systems.
No, it isn't. That distinction applies to every form of computation. The information-storing aspects of a specific configuration of neurons can be utterly demolished without harming the neurons themselves.
All information processing involves changes in some physical state - what, do you think our electronic computers' software exists in some kind of platonic space? - but those changes do not imply that the physical substrate emulating a calculation are damaged by the change. The patterns of neural activity in a human brain that are the software can go awry or be totally destroyed without any harm being done to the physiology of the brain.
"The patterns of neural activity in a human brain that are the software can go awry or be totally destroyed without any harm being done to the physiology of the brain."
It is misleading and counterproductive to make an analogy between "patterns of neural activity" and "software", on the one hand, and between "the physiology of the brain" and "hardware", on the other. In fact, neuroscientists consider patterns of neural activity to *be* a central aspect of the "physiology of the brain".
Patterns of neural activity arise out of the physiological properties of individual neurons, synaptic connections between neurons, and sensory inputs (among other things). The actual relationships between these biological functions, neural activity, and information processing are what neuroscientists study. We do not waste our time drawing an arbitrary line between "software" and "hardware" in this context.
It might be superficially appealing to try to apply the computer science concepts of software and hardware to neural information processing. Nevertheless, this distinction is useless for guiding the design and analysis of experiments that address hypotheses about how brains process information.
The distinction is extremely important for understanding the difference between cognitive and physiological malfunction. The fact that the distinction is irrelevant in some contexts does not render it irrelevant in all. A physicist or engineer specializing in the study of transistors on the atomic and subatomic level would be quite right in saying that all output states of a computer are the result of physical interactions, but "physical interactions" do not equate to "hardware". You seem to have difficulty understanding the concept of levels of implementation.
Cognitive errors do not imply physiological failures precisely because problems with a higher level of implementation do not imply problems with the lower, more fundamental levels.
I think Shelley was wrong in her suspicion that the condition we're discussing is a cognitive problem instead of a more fundamental one, but the distinction she made (and that Michael objected to) is quite valid within the context of the levels of implementation being discussed. The condition Adams suffers from is almost certainly not a problem with his mind but a problem with his neurology.
"The condition Adams suffers from is almost certainly not a problem with his mind but a problem with his neurology."
You seem to have difficulty understanding that neuroscientists do not fruitfully distinguish "mind" from "neurology". There is no "difference between cognitive and physiological malfunction". Cognition is the physiological function of the brain.
The distinction you are drawing has superficial appeal, but unless you can explain how it leads to any interesting testable hypothesis about how the nervous system processes information, you have failed to establish its utility.
(Wow, now it sounds like we are talking about string theory!)
I didn't use the terms hardware and software first, and I find an arbitrary division between them to be not helpful.
As a cognitive psychologist, yes, I like to think about, in Marr's words, the representation and algorithm level of processing irrespective of the platform upon which the processes will run. However, Marr also writes that "These levels (of processing; Computational Theory, Representation and Algorithm, Hardware Implementation) are coupled, but only loosely. The choice of an algorithm is influenced for example by what it has to do and by the hardware in which it must run."
As a neuroscientifically-oriented person, however, I'm competely in agreement with PysioProf -- he writes the way I also think about the problem(s) here.
You're really, really not comprehending. The distinction IS the statement that the nervous system processes information. They're equivalent concepts.
Shelley questioned whether Adams' problem was neurological rather than cognitive, and Michael then suggested that cognitive problems were inherently neurological in nature, which is completely incorrect. Neurologists don't deal with information processing, they deal with physiology - neurologists are to the brain what electrical engineers are to electronic computers. Only far, far less knowledgeable about the system they study.
Go read GEB and the parable of the ants.
That. Is. Precisely. My. Point.
To use the terms you've brought to the table: hardware implementation is only loosely connected to the computation taking place. Given a specific algorithm, there is no way of determining which of the infinitely many hardware implementations whose logical structures are equivalent to the algorithm is actually running it. This principle is what makes emulation possible: an algorithm can be encoded within the structure of a system that is itself an algorithm running on a deeper system. A virtual computer, capable of executing programs, is itself a program being executed by the hardware of our computers - and it is just as much a computer as the physical wires and chips, even though it exists on a different level of implementation.
The structure encoded within the hardware can be defective in some way without the hardware itself being defective, just as the virtual computer can be flawed without implying a flaw in the physical computer that contains it.
caledonian, you are cherrypicking by not looking at the second of the two statements I quoted, and by not considering what I said about how a cognitive psychologist *can* think about these matters (and how I can teach about them) as opposed to how a neuroscientist thinks about them.
It's useful to think about process independent of "hardware" but that doesn't mean I think they are independent.
Again, I ask: What "cognitive" problem is undescribeable by reliance upon a neurophysiological explanation? Please, be specific. I gave you one with TOT states; can you be so kind as to help me out?
I have yet to hear you tell me about, specifically, a "cognitive" problem that doesn't have
Of course they're not independent! No one has suggested that they are, and frankly I find your suggestion that someone did to be offensive. I can't tell whether you're being inflammatory on purpose or by accident, but neither possibility reflects well on you.
There are no cognitive problems that cannot be described in terms of neurophysiology, by definition. No one here has suggested that such a thing is possible. That does not mean that any given cognitive problem is the result of a neurophysiological problem.
"Go read GEB and the parable of the ants."
I have read Hofstadter's book in detail. While it is arguably interesting as speculative philosophy, it is completely irrelevant to the business of designing and interpreting experiments directed at elucidating the biological mechanisms that underlie neural information processing.
For a von Neumann architecture computer--whether implemented directly on electronic hardware or on a virtual machine--it is *useful* to explicitly distinguish between the machine architecture (i.e., hardware) and the program that runs on that architecture (i.e., software). This distinction helps one to understand and explain how and why the computer processes information the way it does.
For a biological nervous system, the software/hardware distinction is simply not useful in understanding or explaining how brains process information. The distinction sounds very philosophically appealing in the abstract, but when you grapple with applying it in experimental contexts to actual instances of neural information processing, it comes up wanting.
First, there is no non-question-begging way to distinguish which aspects of neural function are software and which are hardware. Second, even if there were, such a distinction would not lead to any interesting and testable hypotheses about neural information processing that do not already arise out of a physiological point of view that fails to make the distinction.
In my opinion, a key conceptual distinction in neuroscience that actually helps one design interesting and illuminating experiments is that between the intrinsic computational properties of individual neurons and the emergent properties of neuronal networks.
I'm sorry, I misspoke. Go read GEB until you understand it, which judging from your comments will be quite a while.
'Speculative philosophy'?! Good God, a rudimentary point that computer scientists, engineers, and mathematicians have understood for more than 150 years, and he calls it 'speculative philosophy'.
"There are no cognitive problems that cannot be described in terms of neurophysiology, by definition. No one here has suggested that such a thing is possible. That does not mean that any given cognitive problem is the result of a neurophysiological problem."
What I would say is that any given cognitive problem *is* a neurophysiological problem. It may not involve an identifiable defect in the computational properties of individual neurons, or even local networks, but it must reflect aberrant patterns of neural activity at some level of organization. Thus, it is still neurophysiological.
At what level of neural organization would you have us draw the line between software and hardware? And once you have positioned that line, how does it help us to understand neural information processing, both normal and disordered?
"I'm sorry, I misspoke. Go read GEB until you understand it, which judging from your comments will be quite a while.
'Speculative philosophy'?! Good God, a rudimentary point that computer scientists, engineers, and mathematicians have understood for more than 150 years, and he calls it 'speculative philosophy'."
Hofstadter's book makes many points, so I'm not sure what particular point has you so inflamed. Regardless, none of them are of any relevance to empirically understanding and explaining how nervous systems process information.
The brain is programmed by input (sensory stimulation for example) that actually changes its physical hardware (neurons).
The hardware of a computer is static and unchangeable; it simply interprets the instructions given to it by its software.
The two are simply not the same kind of system, and in the brain the hardware acts as the actual software and are therefore interchangeable - in my humble opinion.
I don't see why people get so offended by intellectual qualms. Just keep an open mind.
Our computers are programmed by input that actually changes its physical hardware. The difference between them and biological neural nets is that the first has discrete and specific hardwired components and the second does not.
I don't care about your opinion, and your facts are wrong. RAM is hardware that changes in order to emulate software.
"The difference between [digital computers] and biological neural nets is that the first has discrete and specific hardwired components and the second does not."
Biological nervous systems definitely possess "discrete and specific...components": neurons. It is not at all clear what you mean by "hardwired" in this context.
Maybe we could clarify this discussion if you defined some of the terms you are using, such as "software", "hardware", "hardwired", "emulate", etc. Once you do that, please let us know exactly how you think that applying these concepts to biological nervous systems would be useful in posing hypotheses and designing experiments that are directed at understanding how biological nervous systems process information, in the contexts of normal or pathological functioning.
You have made the positive claim that the distinction between "software" and "hardware"--or between "cognitive" and "physiological" function--is *useful* in understanding how biological nervous systems process information. This could be an interesting claim, but you have not provided any reasons at all--other than vague references to Hofstadter's book--in support of this claim. If you have such reasons, now would be a good time to present them.
Otherwise, we are just left with your conclusory question-begging assertions.