Why Cognitive Enhancement Is in Your Future (and Your Past)By Ross Andersen

Using technology to enhance our brains sounds terrifying, but using tools to make ourselves smarter may be part of humans' nature.

It could be that we are on the verge of a great deluge of cognitive enhancement. Or it's possible that new brain-enhancing drugs and technologies will be nothing compared to how we've transformed our minds in the past. If it seems that making ourselves "artificially" smarter is somehow inhuman, it may be that similar activities are actually what made us human.

Let's look at the nature of the new technology. Last week a team of ethicists from Oxford released a paper on the implications of using Transcranial Direct Current Stimulation (TDCS) to improve cognition in human beings.  Recent years have seen some encouraging, if preliminary, lab results involving TDCS, a deep brain stimulation technique that uses electrodes placed outside the head to direct tiny painless currents across the brain. The currents are thought to increase neuroplasticity, making it easier for

neurons to fire and form the connections that enable learning. There are signs that the technology could improve language acumen, math ability, and even memory. The Oxford paper argues that TDCS has now reached a critical stage where its risks must be carefully considered before the research goes further.

Of course, not everyone is convinced that the technology will pan out. Some remain skeptical of TDCS, calling it a fad, the latest in a long series of "neuro-myths" that bubble up when scientists distort or embellish their findings in the name of publicity. But even if brain stimulation fizzles, the questions raised by the Oxford paper are going to be with us for a long time. That's because TDCS is just one of many promising new technologies that neuroscientists hope will enhance cognition, including smart pills, genetic engineering, and brain-to-computer interfacing. As deep brain stimulation has become the flavor du jour in neuroscience, bioethicists have increasingly given it a starring role in the thought experiments they use to tease out the philosophical dilemmas posed by cognitive enhancement.

Allen Buchanan is one such bioethicist. As a Professor of Philosophy at Duke University and a consultant to the President's Council on Bioethics, Buchanan has written extensively about the ethical implications of human enhancement. In his most recent book Better Than Human he makes a sustained philosophical case for pursuing human enhancement, arguing that its critics often proceed from a deeply flawed understanding of human nature. Last week I spoke with Buchanan at length about the ethics of deep brain stimulation, the history of cognitive enhancement, and what a world of cognitively enhanced human beings might look like.

Some have argued that enhancement, cognitive or otherwise, is somehow antithetical to human nature. Part of your response to that argument, if I understand it correctly, has been to say that the drive toward enhancement is actually very much a part of human nature. Can you elaborate on that a bit?

Buchanan: I think that any appeal to the notion of human nature, on either side of the enhancement debate, is tricky and problematic and has to be handled with care. Yes, in one sense we might say that it's part of human nature to strive to improve our capacities. Humans have done this in the past by developing literacy and numeracy, and the institutions of science, and more recently we've done it with computers and the Internet. So, yes, if an alien were looking at humanity and asking "What is human nature?" one of the ingredients is going to be that these beings seem quite concerned with improving their capacities and they seem to have a knack for doing it.

On the other hand, sometimes people say that we shouldn't engage with these technologies because we could somehow damage our nature or interfere with our nature, and in doing so they seem to have a kind of rosy pre-Darwinian view about human nature and about nature generally. They tend to think that an individual organism, a human being, is like the work of a master engineer---a delicately balanced, harmonious whole that's the product of eons of exacting evolution.

Now that's one account of human nature, but I want to contrast it with another one from Charles Darwin who wrote in a letter to Joseph Hooker: "What a book a devil's chaplain might write on the clumsy, wasteful blundering, low and horribly cruel works of nature" and by the works of nature, he's talking about us. And so these are two quite different views about nature and about human nature, and if you begin with the first one, the sort of rosy and pre-Darwinian view, then you're almost bound to conclude that anything we try to do to improve ourselves is bound to be a disaster, that any form of intervention is going to end up looking like reckless, foolhardy behavior. On the other hand if you take the Darwinian view and think of human beings as being like any other organisms---sort of cobbled together beings, products of mutation and selection and the crude development of ways to cope with short term problems in the environment, then you'll be more open to the idea that we should at least consider the possibility of improving ourselves.

Humans have done enhancement in the past by developing literacy and numeracy, and the institutions of science, and more recently we've done it with computers and the Internet.

The list of design flaws in human beings is pretty long, as it is in other organisms, and so to think that somehow we're at the summit of perfection and that we're stable is to have the wrong idea of human nature. The misleading assumption is that if we don't interfere, we're going to continue the way we are, and of course that goes completely contrary to everything we know about evolution. In fact it might turn out that the only way to prevent us from going extinct, or to prevent some great worsening of our condition, is to enhance some of our capacities.

When I was a child, which was quite some time ago, in textbooks in public schools you often saw this depiction of some sort of primordial being pulling itself out of primordial soup, sort of a half fish half mammal sort of thing, and then just to the right of that in this line of development, there would be an apelike creature walking on all fours, then you see a Neanderthal walking partly upright, and then you see a human being walking fully upright, and then that's the end. There's no indication that things could get better or worse after that. And that's the picture that we're the summit of the evolutionary process and of course that's really just importing the old pre-Darwinian view and giving it a superficial coating of Darwinian terms.

Human enhancement has been a frequent subject in popular culture, even if its treatment there has often been superficial. Have films like Gattaca or Limitless primed the public for thinking about the ethical implications of these technologies?

Buchanan: It's interesting you mentioned both Gattaca and Limitless because they're quite different. Gattaca is, in a way, representative of the majority of films that tackle these topics, which tend to be very dark. They tend to play on the anxieties people have about these technologies, and they tend to take a very negative view of their social consequences. Gattaca, for instance, paints a fairly grim picture, because it looks at the effects of genetic engineering on human beings simply in terms of its potential for

creating a caste system, and I just think there's more to it than that. Limitless on the other hand, at least as I saw it, seemed to be much more positive and seemed to convey that people could have quite legitimate interests in cognitive enhancement technologies, and that the people who desire these technologies aren't just cranks or people who have inappropriate desires.

"One thing that Limitless missed is the interactive benefit of these enhancements."

One of the most common objections to cognitive enhancement--one that Gattaca addresses in the context of genetic engineering--stems from the fear that cognitive enhancements might exacerbate social inequality by disproportionately advantaging elites. You have argued, persuasively I think, that some examples of previous cognitive enhancement technologies, like literacy and mobile phones, have diffused rapidly across classes after some initial period of monopolization by elites. Are there good reasons to think cognitive enhancement will follow suit?

Buchanan: I think that it depends on which kind of cognitive enhancements you're talking about, especially which modes of technology are being used. If you're thinking about something like surgical procedures for implanting genetically engineered tissue into someone's brain, or if you're talking about very high tech brain to computer interfacing technologies or the genetic engineering of human embryos, presumably those technologies are going to be very expensive and won't be available to a lot of people. So if that's the direction that we go, there might be very serious problems of inequality.

On the other hand cognitive enhancements like TDCS and cognition-enhancing drugs may become inexpensive fairly quickly, and in turn might diffuse much more rapidly than literacy did. This is especially clear in the context of prescription drugs. Right now if you go to Wal-Mart there are over one hundred and thirty drugs that used to be on patent and have now gone off patent and gone generic, and a month supply of each of these drugs is only four dollars. Now that's a lot cheaper than the cognitive enhancement drug that you get at Starbucks. So yes in the future there might be a period when these drugs

are on patent, and are expensive, but when they go off patent they could become very inexpensive.

And also it's important to bear in mind that this may not be something where access to the market is an issue at all. If it turns out that some safe version of TDCS has dramatic cognitive benefits, then governments may view these as very important for national productivity and they may subsidize them in the way they now subsidize education for the very same reason.

Cell phones are another example. No one dreamed that cell phones would become available so rapidly to hundreds of millions of people around the world. But some technologies do diffuse slowly, and where they diffuse slowly there's a potential for problems of inequality.

Assuming then that some cognitive enhancements will spread rapidly across socioeconomic lines, is there a fear that they might make society more likely to produce certain outliers on the continuum of human personality--say, evil genius figures capable of horrific atrocities. If this technology increases the set of highly intelligent individuals within a certain population, won't it also increase the chances that those individuals will overlap with the small set of homicidal, or even genocidal maniacs within a population? I'm thinking of someone like Pol Pot with the intellectual capacities of a figure like Richard Feynman.

Buchanan: At present we don't know enough about the connections between intelligence and personality to know how serious a risk that is but I think it's a risk worth considering. I mean there's another way to look at this, and that is that there is a general problem here. We've developed technologies, which are so powerful and so readily accessible that a very small number of people can use them to create great harm, and that's just due to the success of science.

Even today, without a tremendous amount of specialized knowledge, people may be able to produce lethal viruses that we don't have much immunity to, or a small terrorist group can acquire some plutonium and put it in a municipal water supply and kill lots of people. So in one way this is a more general problem about how powerful our technologies are and the fact that they can be used for good or for ill by small numbers of people---people who are not subject to the discipline of large organizations like states, who aren't subject to the logic of deterrence that state actors are subject to.

Now the other side of this coin is that if there's a general ramping up of intelligence, then presumably there's also going to be a lot more people who are very intelligent and who have good motivations, and who will be committed to trying to constrain the bad apples and prevent them from doing damage.

You also have to consider the possibility that cognitive enhancements may go hand in hand with moral enhancements. There's a great debate as to what extent bad behavior results in part from flawed cognitive processes, but even if improving our intelligence is

not by itself is not likely to make us behave better, it may turn out that some of the same knowledge we're using to make cognitive enhancements---knowledge about the relationship between our brains and behavior--- may allow us to develop what some people have called "moral enhancements." And if that happens, that may be something that will at least reduce the kind of risk that you're talking about, because you're right that people who have a super-developed intelligence along with a moral sensibility that's dwarfed in comparison could be a real problem.

An incomplete picture?

It strikes me that the development of "moral enhancements" would probably rip open five or six new subfields in bioethics.

Buchanan: Oh I agree and it already is, and it's very tricky. Cognitive enhancement is something that's relatively easy for people to understand, because it's easier for people to see what's controversial about it because it's easier to see what counts as a boost in cognitive performance. When it comes to moral performance, we have all sorts of problems that have to do with disputes about what a moral improvement is, what the moral virtues are, and that sort of thing.

We also have interesting precedents, interesting examples of existing morally enhancing technologies, like religion, social morality, institutionalized morality---there's no question that these have increased our capacity to interact with each other. Even legal systems have been moral enhancements in some respect because they've enabled us to control our aggressive impulses, to find ways of settling disputes that are more morally acceptable.

People who have a super-developed intelligence along with a moral sensibility that's dwarfed in comparison could be a real problem.

And it might turn out that there are some biochemical interactions that might stimulate our moral imagination, increase our empathy towards others, or, in the cognitive

dimension, might improve our powers of moral judgment and reasoning. There's a lot of interesting literature now on what are called normal cognitive biases, cognitive flaws in cognitively normal people. Some of these cognitive flaws might have bad moral consequences in certain contexts, and so it's possible that by reducing some of those we might make ourselves better off also. 

Putting aside the outliers, the extreme personalities, some neuroethicists are worried about what they call ''hyper-agency,'' the notion that as human beings become more able to control their lives and themselves, they also become less constrained by traditional limits, and that human wisdom will ultimately be insufficient to manage that kind of freedom.

Buchanan: Look, I think this is a genuine problem. It's the old problem of hubris, and it's important to recognize that it doesn't just apply to cognitive enhancement or even biomedical enhancement more generally, it applies to all human interventions, technological or social or economic or political. One thing I would point out is that even though the worry about hubris is a serious one, it's hard to see how it could be a conclusive argument against biomedical enhancements across the board. Instead it's like all genuine concerns---it has to be given due weight and then balanced against the potential benefits of these technologies.

So while I think we should take the problem of hubris seriously, I also realize that it's not a local problem for biomedical enhancements, it's something we face everywhere and that consequently, it can't be a conversation-stopper. We have to take a more fine-grained approach, because there's no sort of general answer to the question "how should we go slow" or "how we should use due caution" for all of these different technologies. Different modes of enhancement in different contexts are going to have different risk benefit profiles.

A lot of people worry that the widespread use of cognitive enhancement will mean raised standards in the classroom and in the workplace. And while that may turn out to be a net positive for society, there is a fear that individuals who would rather not participate in cognitive enhancement will be forced to just to keep up with their enhanced coworkers, and that such pressures would constitute a kind of soft coercion.

Buchanan: That does worry me; I think it's a very reasonable concern. Now, again, it's not a conversation stopper, it's not something that would lead to the conclusion that we shouldn't develop these technologies. I think the situation you've described is quite widespread in sports. Some athletes, or even a majority of athletes, would prefer not to use enhancement drugs, but they do so in a defensive manner to prevent being put at a disadvantage when others use them. It's also a concern with the off-label use of drugs like Adderall, drugs that have not been developed specifically for the kind of cognitive enhancement they are often used for.

It would be better if we would bring these cognitive enhancement drugs out of the closet, and do regular clinical double-blind trails with them

The worst case scenario is where large amounts of people feel this pressure to use a drug even though they would prefer not to do it, and it's happening in a kind of unregulated context as it is now (with Adderall) and many people may be led to set aside reasonable worries about bad side effects because of this pressure, this soft coercion you're talking about. We have a huge unregulated experiment going on in this country, and in many other advanced countries I suspect, where a large population of university students are using these drugs, and that's unfortunate because it might be that five years from now or ten years from now it's going to be discovered that these drugs have some large scale adverse effect. It would be better if we would bring these cognitive enhancement drugs out of the closet, and do regular clinical double-blind trails with them, and genotype the people that take them and later if there's an adverse effect, see if it only affects people with a certain genotype, and be in a better position to prevent the wide diffusion of these drugs before they're safe.

Again, though, it's not confined to cognitive enhancement drugs or biomedical enhancements; I'm sure there are lots of people who used to be able to qualify for a job without an advanced degree, and now they have to have an advanced degree, and so they're "coerced" into getting that degree whether they think it gives them that much benefit or not. Similarly, if you're raising a child in a society where literacy is a necessary condition for any job worth having, you're going to be under pressure to make sure your child learns how to read and write. So these aren't necessarily bad things, they're only bad if they lead people to disregard reasonable worries about the risks of these technologies.

"Yeah, we're going to need you to put those electrodes on now."

Some of the films about cognitive enhancement make it look pretty dull in practice. I remember seeing Limitless and thinking "so this guy ramps up to these breakout levels of raw intellect and creativity and the best he can do is a Wall Street job and a fancy car?" And that's an extreme example---there have been other, deeper explorations of enhancement, particularly in the superhero genre---but on the whole it seems like the subject has been treated pretty unimaginatively. What have you thought of that's really far out there, culturally or intellectually, that cognitive enhancement might bring about?

Buchanan: While I do think Limitless was more sympathetic toward these technologies than most pop culture representations of them, there's no question it was a little disappointing in terms of what was considered to be a fantastic improvement in the quality of this individual's life. I think one thing that Limitless missed is the interactive benefit of these enhancements. Cognitive enhancements in particular tend to have what economists call network effects, meaning that the value of you having the enhancement increases as more people have it.

Think about having a computer. If you have a computer, that's good you can do a lot of things with it, but part of what makes having your computer so valuable is that hundreds of millions of other people have computers. Similarly with literacy, if you were the only person who knew how to read certainly that would give you some advantages, but you wouldn't have nearly as rich a world as the one we live in where billions of people are literate.

So, I think perhaps one of the problems with Limitless was that it portrayed this guy by himself having much more developed cognitive capacities than other people, so it overlooked the fact that if lots of people have cognitive enhancements, there might be completely new forms of interaction, new kinds of social relationships, new forms of productivity and human flourishing, or new kinds of intrinsically enjoyable activities that we just don't have access to now.

I have an analogy for this, and the reason it's an analogy is that by the nature of the case it's hard for us to imagine what these new forms of interaction will be, and how rewarding they might be, but here's the analogy. Consider two card games: one is the child's game of "go fish" and the other is contract bridge. Now it might turn out that in the future if huge numbers of people are cognitively enhanced, they will look back at the kinds of activities that people in our world perform and say "that was like children playing go fish."

Think about the kinds of interactions that we now have, and the kinds of enjoyments and productivity we can have because of the Internet. If you try and ramp that up, if you magnify it by many orders of magnitude, you might begin to get an idea of how human life could be if many hundreds of millions of people were cognitively enhanced.

Because TDCS is thought to pair especially well with active learning, it's been suggested that it might be grafted on to media devices of one sort or another. Some

have even imagined that in the future iPads and Kindles may come with these electrodes attached, so that you could read in some heightened state of neuronal connectivity. If such a technology were to become safe and available, what would be the first thing you'd read while attached to it?

I've actually heard that the people using this stuff in labs are using it on themselves the way in the way that the rest of us use coffee breaks

Buchanan: It's funny; I've actually heard that the people using this stuff in labs are using it on themselves the way in the way that the rest of us use coffee breaks. But that's a good question, I might go back and try to read an organic chemistry text that I had a lot of trouble with as an undergraduate. Or maybe I'd try to read Kant's Critique of Pure Reason in the original German and see if it's still as impenetrable to me as it was thirty years ago.

You're obviously someone at the outer edge, the innovating edge, of a particular field. I'm curious as to whether you'd want to use cognitive enhancement technologies in order to go deeper in that field, or would you try to expand your range of abilities, like you mentioned with the organic chemistry.

Buchanan: I think that's a question that many people are facing on a smaller scale, because as information becomes available more readily through the Internet, more forms of independent learning are available, and as people live longer, at least people in relatively affluent societies, they're facing this question. They may have specialized in something for most of their productive life, but now they realize they have another twenty years---I'm 63 years old right now, and I'm sort of thinking about what I want to be doing for the next fifteen or twenty years, however long it is that I'm going to be alive.

And that's a real question, the question of whether I should keep hammering away at the things that I do and try to do them better, or whether I should make some kind of radical change and go into some new area, or a diversity of areas, and I think that if the technologies we're talking about are developed it's going to add to the scope of that kind of choice, and I think that's probably a good thing. 

This article available online at:

http://www.theatlantic.com/technology/archive/2012/02/why-cognitive-enhancement-is-in-your-future-and-your-past/252566/

Copyright © 2012 by The Atlantic Monthly Group. All Rights Reserved.

http://www.theatlantic.com/technology/print/2012/02/why-cognitive-enhancement-is-in-your-future-and-your-past/252566/

Child-testing debate divides scientists

By Christian Shepherd | Last updated: 14:18, 02/02/2012

Research suggesting that brain stimulation can improve learning abilities has opened up debate about the ethics of testing such techniques on children.

Dr Roi Cohen Kadosh of Jesus College has found that Transcranial Direct Current Stimulation (TDCS) can improve mathematical abilities, not only during stimula- tion, but for a prolonged period of time afterwards as well.

Delivering low current, non painful stimulation every day for five days of a week while the participant completed a mathematical task showed that, compared to a control group, those that received TDCS had significantly improved performance. Cohen Kadosh said that his study is only the most recent of many different experiments that have found improvement in various cognitive learning abilities following TDCS, including language, motor training, working memory, and decision making.

While researchers are continuing to look at the effects of TDCS on adults, Cohen Kadosh described how they are also planning to look at the effects of such techniques on children with learning disabilities.

On BBC Radio 4’s Today Programme Prof Barbara Sahakian of Cambridge University brought up a number of objections to research with young children as participants, saying that we currently lack the knowledge to make this move.

Sahakian said: “We have to consider the risk benefit analysis when we do this. At the moment I don’t think what we know about these techniques, especially their long term safety, justifies using these techniques in studies with typically developing children.”

Practical ethicist Julian Savulescu of Oxford disagreed with ranted on kids at the lower end of Sharakian. Savulescu said: “We simply won’t be able to predict whether it is beneficial in normal kids without doing the experiments”, since “something that appears safe in the developed brain may be unsafe in the developing brain.”

He added: “Since the normal variation in ability to learn is so significant, studies are at least warranted on kids at the lower end of the learning curve.”

Savulescu noted that the issues of coercion are applicable to all aspects of life, but suggested that they are most objectionable when “the technology is expensive and only affordable to some” and when “it has significant risks, so exposing people to unreasonable risks just to keep up.”

He added that these objections are not sustainable in the current case since “this is cheap and could be subsidized if effective, like public schooling” and because, after further research, we will able to identify the risks; “If it is safe, it is not a problem. If it is risky, it should be regulated, like medicines.”

Savulescu did say, however, that “if there are significant downsides it should only be available from, and under monitoring by, professionals. Of course people could abuse this, like they abuse medicines, but abuse can never be fully prevented.”

Sahakian also brought up the issue of coercion asking: “Will people be forced to use this? Will other children be using it and therefore parents will feel pressure on themselves to use it on their children?”

http://oxfordstudent.com/2012/02/02/child-testing-debate-divides-scientists/

Transcranial direct-current stimulationFrom Wikipedia, the free encyclopedia

This article may contain wording that merely promotes the subject without imparting verifiable information. Please remove or replace such wording, unless you can cite independent sources that support the characterization. (April 2011)

Transcranial direct current stimulation (tDCS) is a form of neurostimulation which uses constant, low current delivered directly to the brain area of interest via small electrodes. Currently, tDCS is used as therapy for certain psychological disorders such as anxiety disorders and depression, as well as a tool for motor rehabilitation in stroke patients.

Contents

 [hide]  1 History

o 1.1 Discovery o 1.2 Transition into modern scientific research

2 How it works o 2.1 Parts

o 2.2 Set up o 2.3 Types of stimulation

3 Effects on brain 4 Comparison to other devices

o 4.1 TMS o 4.2 Other types of stimulation

5 Safety o 5.1 Safety protocol o 5.2 Side effects of stimulation o 5.3 Risks

6 Uses o 6.1 Clinical o 6.2 Psychological

7 References

[edit] History

[edit] Discovery

The basic design of tDCS, using direct current to stimulate the area of interest, has been around for over 100 years. There were a number of rudimentary experiments completed before the 19th century using this technique that tested animal and human electricity. Luigi Galvani and Alessandro Volta were two such researchers that utilized the technology of tDCS in their explorations of the source of animal cell electricity. It was due to these initial studies that tDCS was first brought into the clinical scene. In 1804, Aldini started a study in which he used the technique of direct current stimulation and was successful in improving the mood of melancholy patients. Unfortunately, this discovery did not receive much attention and was forgotten in the light of other types of neurostimulation. When electroshock therapy was developed in the 1930s and was found to be a relatively effective treatment against depression, therapy using tDCS was abandoned.[1]

[edit] Transition into modern scientific research

There was a brief rise of interest in transcranial direct current stimulation in the 1960s when studies by the researcher Albert proved that the stimulation could affect brain function by changing the cortical excitability. He also discovered that positive and negative stimulation had different effects on the cortical excitability. Although these findings were important in the use of tDCS in therapy, research in this area was again dropped as drug therapy proved to be a more effective and simple method of therapy. Transcranial magnetic stimulation It wasn’t until recently that tDCS was rediscovered for a third time. This time, the rediscovery was fueled by an increase of interest and understanding of basic brain functioning as well as new brain stimulation and brain imaging techniques such as TMS and fMRI. Now, Transcranial direct current stimulation

is beginning to be used more frequently as a brain stimulation technique because safety protocol has shown that tDCS is extremely safe for human use.[1][2]

[edit] How it works

Transcranial direct current stimulation works by sending constant, low direct current through the electrodes. When these electrodes are placed in the region of interest, the current induces intracerebral current flow. This current flow then either increases or decreases the neuronal excitability in the specific area being stimulated based on which type of stimulation is being used. This change of neuronal excitability leads to alteration of brain function, which can be used in various therapies as well as to provide more information about the functioning of the human brain.[2]

[edit] Parts

Transcranial direct current stimulation is a relatively simple technique and contains only a few parts. These include two electrodes and a battery powered device that delivers constant current. Control software can also be used in experiments that require multiple sessions with differing stimulation types such that neither the person receiving the stimulation nor the person administering the stimulation knows which type is currently being administered. Each device has an anodal electrode and a cathodal electrode. The anodal electrode is the positively charged electrode and the cathodal electrode is the negatively charged electrode. The current flows from the anodal electrode to the cathodal electrode, creating a circuit. The device that delivers the current has controls that set the current as well as the duration of stimulation.[3]

[edit] Set up

To set up the tDCS device, the electrodes and the skin need to be prepared. This ensures a strong connection between the skin and the electrode. The careful placement of the electrodes is crucial to successful tDCS technique. The electrode pads come in various sizes with benefits to each size. A smaller sized electrode achieves a more focused stimulation of a site while a larger electrode ensures that the entirety of the region of interest is being stimulated.[4] If the electrode is placed incorrectly, a different site or more sites than intended may be stimulated resulting in faulty results.[2] One of the electrodes is placed over the region of interest and the other electrode, the reference electrode, is placed in another location in order to complete the circuit. This reference electrode is usually placed on the neck or shoulder of the opposite side of the body than the region of interest. Since the region of interest may be small, it is often useful to locate this region before placing the electrode by using a brain imaging technique such as fMRI or PET.[2] Once the electrodes are placed correctly, the stimulation can be started. Many devices have a built-in capability that allows the current to be “ramped up” or increased slowly until the necessary current is reached. This decreases the amount of stimulation effects felt by the person receiving the tDCS. After the stimulation has been started, the current will continue for the amount of time set on the device and then will automatically be shut off. Recently a new approach has been introduced where instead of using two large pads,

multiple (more than two) smaller sized gel electrodes are used to target specific cortical structures. This new approach is called High Definition tDCS (HD-tDCS).[5][4]

[edit] Types of stimulation

There are three different types of stimulation: anodal, cathodal, and sham. The anodal stimulation is positive stimulation that increases the neuronal excitability of the area being stimulated. Cathodal stimulation decreases the neuronal excitability of the area being stimulated. An example of how cathodal stimulation could be used is as a therapy for a psychological disorder caused by the hyper-activity of a particular area of the brain. Cathodal stimulation would decrease the neuronal excitability to reach a more stable level of activity.[6] Sham stimulation is important because it is the control stimulation. This stimulation emits a brief current but then remains off for the remainder of the stimulation time. With sham stimulation, the person receiving the tDCS does not know that they are not receiving prolonged stimulation; this provides a control condition for experiments, which can be double-blinded. Without this type of stimulation, the effects of the positive or negative stimulation could not be proven.

[edit] Effects on brain

One of the most important aspects of tDCS is its ability to achieve cortical changes even after the stimulation is ended. The duration of this change depends on the length of stimulation as well as the intensity of stimulation. The effects of stimulation increase as the duration of stimulation increases or the strength of the current increases.[1] The way that the stimulation changes brain function is either by causing the neuron’s resting membrane potential to depolarize or hyperpolarize. When positive stimulation is delivered, the current causes a depolarization of the resting membrane potential, which increases neuronal excitability and allows for more spontaneous cell firing. When negative stimulation is delivered, the current causes a hyperpolarization of the resting membrane potential. This decreases neuron excitability due to the decreased spontaneous cell firing.[2][7]

Neuroplasticity refers to the ability of the brain to change throughout life based on experiences. The way that transcranial direct current stimulation functions could be due to the plasticity concepts of long term potentiation and long term depression since the two share some basic similarities. Long term potentiation is the strengthening between two neurons while long term depression is the weakening between two neurons. These effects are achieved mainly through an alteration of synaptic transmission ability. LTP enhances transmission and LTD hinders transmission. Likewise, tDCS stimulation involves the alteration of synaptic transmission ability through modifications of intracellular cAMP and calcium levels. Also, both LTP, LTD, and the effects of tDCS are protein synthesis dependent. It is for these reasons that LTP and LTD are proposed mechanisms of the function of tDCS.[2][7]

[edit] Comparison to other devices

[edit] TMS

Transcranial direct current stimulation is a relatively unconventional method of stimulating the brain. While this method is gaining interest, the most commonly used method of brain stimulation is transcranial magnetic stimulation (TMS). This technique of brain stimulation utilizes a electric coil held above the region of interest on the scalp that uses rapidly changing magnetic fields to induce small electrical currents in the brain. There are two types of TMS: repetitive TMS and single pulse TMS. Both are used in research therapy but effects lasting longer than the stimulation period are only observed in repetitive TMS. Similar to tDCS, an increase or decrease in neuronal activity can be achieved using this technique, but the method of how this is induced is very different. Transcranial direct current stimulation has the two different directions of current that cause the different effects. Increased neuronal activity is induced in repetitive TMS by using a higher frequency and decreased neuronal activity is induced by using a lower frequency.

Both TMS and tDCS are painless and considered safe for human use. Transcranial magnetic stimulation causes the neuron’s action potentials to fire, resulting in a stronger effect. This larger effect could be beneficial in both therapy and research. Since tDCS only causes increased spontaneous cell firing, it does not have as big as an effect. One benefit of tDCS when compared to TMS is that due to the smaller effect, there is a much smaller chance of causing seizures in the person receiving the stimulation.[3]

[edit] Other types of stimulation

One other technique of electrical stimulation that has been used is called transcranial electrical stimulation, or TES. TES also functions by inducing neuronal change via electrical currents. TES unlike tDCS causes the resting neurons to fire and can be painful to the person receiving the stimulation, so this method is no longer frequently used.[2]

[edit] Safety

When applied following established safety protocols, transcranial direct current stimulation is widely regarded as a safe method of brain stimulation, causing no apparent short-term harm. Safety protocols limit the current, duration, and frequency of stimulation, thereby limiting the effects and risk

[edit] Safety protocol

There has been much work done in the last 10 years to develop a safety protocol for administering transcranial direct current stimulation. Many studies have been conducted to determine the optimal time of stimulation and current used as well as steps to take in order to reduce or eliminate the side effects felt by the person receiving the stimulation. These standards are still not entirely set and continue to expand as more research is done. Currently, the accepted maximum current for human use is 2 mA and usually 1 mA or

less is used. The device itself has a maximum current setting that while above what is suggested to use, it is still within a range in which no harm is done to the person receiving the stimulation.[1]

Studies have been completed to determine the current density at which overt brain damage occurs in rats. It was found that in cathodal stimulation, a current density of 142.9 A/m2 delivering a charge density of 52400 C/m2 or higher caused a brain lesion in the rat. This is over two orders of magnitude from what is currently being used.[8][9][10]

There is no strict limitation on the duration of stimulation set at this point but a stimulation time of 20 minutes is considered the ideal time. The longer the stimulation duration, the longer the observed effects of the stimulation persist once the stimulation has ended. A stimulation length of 10 minutes results in observed effects lasting for up to an hour.

It is generally encouraged to wait at least 48 hours to a week before repeating the stimulation. Also, it is advised to warn the person receiving the stimulation of the possible after effects of the tDCS stimulation.[2]

[edit] Side effects of stimulation

There are a few minor side effects that can be felt by the person while receiving the stimulation, and most of these can be controlled by correct set up of the device. These side effects include skin irritation, a phosphene at the start of stimulation, nausea, headache, dizziness, and itching under the electrode. Nausea most commonly occurs when the electrodes are placed above the mastoid, which are used for stimulation of the vestibular system. A phosphene is a brief flash of light and this effect can occur if an electrode is placed near to the eye.[2] A recent study of over 500 subjects using the currently accepted protocol reported only a slight skin irritation and a phosphene as side effects.[8]

There are several ways to reduce the skin irritation felt during stimulation. One of the most important methods of preventing skin irritation is by preparing the electrodes with saline solution and the skin with electrode cream thoroughly. Also, ramping up the current can reduce the irritation. This is done by slowly increasing the current until the desired current is reached.

[edit] Risks

There are no known risks of tDCS at this time, but since this technique of stimulation is still being explored, safety precautions should be kept. The set protocols must be followed to ensure correct use of the device.[9] Also, it is not advised to administer this stimulation to people susceptible to seizures, such as people with epilepsy. Although seizures do not seem to be a risk for healthy individuals, those with a tendency towards seizures may react differently.[2] As more is discovered about the use of tDCS, the safety

standards may change, making it important to remain familiar with the most currently updated safety protocol.

[edit] Uses

[edit] Clinical

Clinical therapy using tDCS may be the most promising application of this technique. There have been therapeutic effects shown in clinical trials involving Parkinson’s disease,[11] tinnitus, fibromyalgia, and post-stroke motor deficits.[12] In a recent study, stroke patients with speech difficulties displayed great improvement through a tDCS based therapy, with the improvement lasting past the one week retest.[13] Stimulation therapy could also be developed into effective therapy for various psychological disorders such as depression, anxiety disorders, and schizophrenia.

[edit] Psychological

The majority of psychological studies involving tDCS focus on the expansion of knowledge about a certain region of the brain or a certain psychological phenomenon. For example, much work is done on the ability and specifics of working memory.[14] Many of these studies stimulate a particular region of the brain and then observe the effects of the stimulation in some type of cognitive task.

[edit] References

1. ^ a b c d e Utz, K. S., Dimova, V., Oppenlander, K., & Kerkhoff, G. (2010). Electrified minds: Transcranial direct current stimulation (tDCS) and Galvanic Vestibular Stimulation (GVS) as methods of non-invasive brain stimulation in neuropsychology-A review of current data and future implications. Neuropsychologia, 48(10), 2789–2810.

2. ^ a b c d e f g h i j k Nitsche, M. A., Cohen, L.G., Wassermann E. M., Priori, A., Lang, N., Antal, A., Paulus, W., Hummel, F., Boggio, P. S., Fregni, F., & Pascual-Leone, A. (2008). “Transcranial direct current stimulation: State of the art 2008”. Brain Stimulation 1(3), 206–23.

3. ^ a b c Sparing & Mottaghy (2008). Noninvasive brain stimulation with transcranial magnetic or direct current stimulation – From insights into human memory to therapy of its dysfunction. Methods, 44: 329–337.

4. ^ a b c Datta ,A., Bansal V., Diaz J. et al.(2009)Gyri-precise head model of transcranial direct current stimulation: improved spatial focality using a ring electrode versus conventional rectangular pad. Brain Stimul, 2(4):201-207.

5. ^ a b Borckardt, J. J., Bikson M., Frohman H. et al.(2012) A pilot study of the tolerability and effects of High-Definition Transcranial Direct Current Stimulation (HD-tDCS) on Pain Perception. J Pain 13(2):112-120.

6. ^ a b Nitsche, M. A., Nitsche, M. S., Klein, C. C., Tergau, F., Rothwell, J. C., Paulus, W. (2003). Level of action of cathodal DC polarization induced inhibition of the human motor cortex. Clinical Neurophysiology 114: 600–604.

7. ^ a b c Nitsche, M. A. & W. Paulus, W. (2000). Excitability changes induced in the human motor cortex by weak transcranial direct current stimulation. Journal of Physiology, 527 (3): 633–639.

8. ^ a b c Michael A. Nitsche, David Liebetanz, Nicolas Lang, Andrea Antal, Frithjof Tergau, Walter Paulus (2003). Safety criteria for transcranial direct current stimulation (tDCS) in humans. Clinical Neurophysiology 114:2220–2222.

9. ^ a b c Liebetanz, D., Koch, R., Mayenfels, S., König, F., Paulus, W., & Nitsche, M. (2009). Safety limits of cathodal transcranial direct current stimulation in rats. Clinical Neurophysiology 120: 1161–1167.

10. ^ a b Bikson, M., Datta, A., Elwassif, M. (2009.) Establishing safety limits for transcranial direct current stimulation. Clin Neurophysiol 120(6): 1033–1034.

11. ^ a b Boggio et al. (2006). Effects of transcranial direct current stimulation on working memory in patients with Parkinson's disease. Journal of the Neurological Sciences 249:31–38.

12. ^ a b Norris, S., Degabriele, R., Lagopoulos, J. (2010.) Recommendations for the use of tDCS in clinical research. Acta Neuropsychiatrica 22: 197–198.

13. ^ a b Baker, J., Rorden, C., & Fridriksson, J., (2010).Using transcranial direct current stimulation (tDCS) to treat strokepatients with aphasia. Stroke, 41(6): 1229–1236.

14. ^ a b Berryhill, M. E., Wencil, E. B., Coslett, H. B., & Olsona, I. R. (2010). A selective working memory impairment after transcranial direct current stimulation to the right parietal lobe. Neuroscience Letters 479: 312–316.

15. ̂ Richard P. Chi, Allan W. Snyder (2011). Facilitate Insight by Non-Invasive Brain Stimulation. PLoS ONE 6(2): e16655. doi:10.1371/journal.pone.0016655

16. ̂ DaSilva ,A.F., Volz, M.S., Bikson, M., Fregni, F.(2011) Electrode positioning and montage in transcranial direct current stimulation. J Vis Exp,51;pii:2744.

Low-level electrical stimulation may make you smarterJanuary 30, 2012

Debra Black

Researchers at Oxford University have found that low-level electrical stimulation to parts of the brain can improve learning and cognitive function and increase academic performance.

Roi Cohen Kadosh, a cognitive neuroscience scientist at Oxford University’s Department of Experimental Psychology, and a team of researchers have studied about 120

volunteers, looking at their performance in mathematics both before and after what is known as Transcranial Direct Current Stimulation.

The volunteers were divided up into two groups — some were given the stimulation and others were given a kind of placebo stimulation. In his research Cohen Kadosh has found that those who were given the electrical stimulation and received cognitive training in mathematics improved their ability to do it.

In his volunteers, the results lasted for six months after volunteers received 20 minutes of brain stimulation for six days. But in other studies, the cognitive improvements have lasted as long as a year, Cohen Kadosh said in a phone interview with the Star.

The device Cohen Kadosh uses runs on home batteries and the electrical stimulation people receive is very small — a mili amp at most. If someone was to take a home battery and put it on their tongue, they would receive more of an electrical current than with Transcrania Direct Current Stimulation, Cohen Kadosh said.

The technique has huge potential for helping those with the elderly who may have a loss in cognitive function or children with learning disabilities, Cohen Kadosh said.

But there are potential side effects and Cohen Kadosh urges caution. “This isn’t something that should be tried at home. It’s a very new and very young method. We need to know the side affects. We’re looking into it.

“There is lots of potential if it’s safe to be used. We could have it for children at schools who have learning disabilities; healthy people who want to enhance their abilities and the elderly.”

The stimulation, explains Cohen Kadosh, stimulated changes in the thresholds of neurons and that’s how it improves cognitive performance.

“The neurons need to fire in the brain to transmit information. We known in the long term there are some neurochemical changes in the brain and this method induces that in areas involved in learning and memory processes.”

Specifically the low-level electrical stimulation changes the levels of glutamate and GABA (gamma-amino butyric acid) produced in the brain.

Cohen Kadosh is just one of a number of researchers looking at this technique. Research into TDCS is also being done at the National Institutes of Health in Bethesda, Maryland and Harvard University as well as other universities.

Next up for Cohen Kadosh’s lab is testing the technique on children with learning disabilities and the elderly.

He is also discussing the possible commercialization of the technique with a number of companies, but he cautions there are some ethical issues that must be dealt with, including which is the appropriate brain area to be stimulated; what is the effect on the developing brain; is there a risk that cognitive enhancement in one area may impede other areas.

In a report in Current Biology, Cohen Kadosh and his co-authors write: “TDCS studies have shown that it is possible to enhance fundamental human capacities, such as motor and sensorimotor skills, vision, decision making and problem solving, mathematical cognition, language, memory, and attention — improvements that seem to persist without apparent cognitive side effects.”

But the authors add: “There is a substantial risk that it could be utilized prematurely, before proper protocols are established, and potentially before unwanted side effects are well understood, especially with regards to children.”

http://www.thestar.com/news/article/1122472

£500 electric shock machine can boost learning and memory - but scientists worry it could be misusedBy Katie Silver

Last updated at 2:50 PM on 27th January 2012

Researchers have found brain stimulation via small electric shocks can boost memory and learning

A machine which stimulates your brain with tiny electric shocks can improve memory, problem-solving and mathematical abilities, psychologists have found.

But Oxford University researchers have warned that the machine could spell trouble if it gets into the wrong hands or is used incorrectly, especially when it comes to children whose brains are still developing.

While the brain-stimulation technique has been previously used to treat cognitive impairment, new research shows it can also boost mental abilities among healthy adults.

Dr Roi Cohen Kadosh, a neuroscientist, uses a high-tech system called transcranial direct current stimulation (tDCS) to stimulate precise regions of the brain with a tiny buzz of electric current.

When he stimulates the parietal lobes, which are responsible for our skills in reading, writing and numeracy, he can boost mathematical skills.

The electric current triggers the area to produce chemicals that cause brain cells to develop or change. This process — ‘neural plasticity’ — is essential to learning (our brains change structure when we take on new information).

When Dr Cohen Kadosh’s subjects had their parietal lobes stimulated for 30 minutes every day for a week, they were able to pick up maths skills through conventional lessons far more quickly and effectively than they could before.

‘It’s completely safe. The electric current is one thousand times lower than anything that could cause damage,’ he says.

Tests have shown that the subjects’ maths abilities remain boosted six months after the treatment. To someone as numerically illiterate as me, the prospect of growing a ‘maths brain’ is exciting. But Dr Cohen Kadosh’s work is at the vanguard of a medical revolution.

With very little known on the side effects of shocking the brain, vulnerable users could be exploited or even worse, have disrupted, atypical brain development

It heralds a high-tech world of brain medicine where electronics will be used to repair deep faults, such as depression and Parkinson’s, modify problem personalities and boost everyone’s ability to learn, remember and think creatively.

Already a number of home ‘brain-fixers’ are available to buy. These generally work in the same way as Cohen Kadosh’s machine and are sold on the web in the U.S. (though their effectiveness is doubtful).

Still the psychologist, writing in the journal Current Biology, warns against the potential dangers of the technology.

Dr Roi Cohen Kadosh has warned that the device could be very dangerous if used incorrectly

Given the devices are relatively cheap (£500) and portable and there are no laws governing their use, they could be severely misused.

The researchers say: ‘When used within suggested guidelines, the acute safety risks (of seizures, for example) seem very low. There is a danger that it can be tried out ad hoc on adults and children — especially on vulnerable patient groups seeking help with serious and currently intractable developmental disorders

He said not enough is known on side effects and there are no training programs for administering the device. 

‘At best, this situation could result in the exploitation of vulnerable patients or parents for financial gain; at worst, it may risk long-term damage to the brain and exacerbate the disadvantage, potentially worsening other psychological functions.

It is especially problematic when it comes to using the device on children where misuse could not only worsen performance but could lead to ‘atypical brain development.’

‘Like other types of atypical experience during sensitive periods, the stimulation of the wrong brain area might induce abnormal patterns of brain activity in this brain region and interconnected areas, and increase metabolic consumption in brain areas that are irrelevant to the specific psychological function. 

‘Hence, research into the safety and potential hazards of TDCS in children is urgently needed.’

It is also dangerous in terms of how the different parts of the brain interact:

‘Highly-developed capacities in certain cognitive domains in some individuals are accompanied by reduced functioning in others.

'It would be premature to allow children, or their parents, to make the choices that lead to higher functioning in one domain (such as language) at a cost to functioning in other valuable domains (such as face recognition).’

For this reason, he suggests that parents should perhaps be banned from using the device.

‘If TDCS does enhance some abilities at a cost to others, then assessing its ethical permissibility will involve weighing its costs and benefits,’ he said.

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I used a machine like this now I can divide, and subtract but can not remember how to wipe my butt. I now am sprayed off with a hose by my live in caretaker while I do sudoku puzzles. Small price to pay for intelligence if you ask me. Pros definitely outweigh the cons the only thing different is now people won't give me hugs or walk behind me which troubles me deeply.

- Mr. Messy Buns, Virginia, 29/1/2012 00:30

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If they brought these out in 2004 I could have gone to a better university

- James, UK, 29/1/2012 00:21

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@Lady Pauline Maria: while the jury may be out on aspsrtame, flouride in water is actually a good thing. In one region here, wowsers won the right to remove flouride from their water supply (the same wowsers who still believe vaccines cause autism). In 5 years

the incidences of cavities in children's teeth grew by 600% Yeah that was a great idea. Armchair scientists like you cause more problems than flouride in water, honey!

- KJ, Wellington, NZ, 28/1/2012 22:58

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ECT for the masses, the world has gone totally mad!

- Life is a pie chart, UK, 28/1/2012 22:22

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ECT for the masses, the world has gone totally mad!

- Life is a pie chart, UK, 28/1/2012 22:22

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This is Joe 90 technology becoming true.

- Charles Siu, London, 28/1/2012 19:00

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Shocking thing to do.

- Graham, Thailand, 28/1/2012 15:39

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Can they be put in cushions for MP's to sit on ?. Then they could simulate their brains while they sat there..........

- derekkidd, romania ex uk, 28/1/2012 14:49

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Actually, the device is so simple that the component cost is less than £5 - not £500

- Dirk Bruere, Bedford, England, 28/1/2012 14:23

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"....maths skills through conventional lessons" You still have to study. If people were too lazy to study when they were stupid, what makes one think they will study when they are smart? "....boosted six months after the treatment." Isn't that the way it is now? A person running for office is the best and the brightest. He has all the answers and can solve all the problems.Six months after being elected, he's just another damn fool that doesn't have a clue as to what is going on.

- Southern Hoosier, Greenville, SC United States., 28/1/2012 11:58

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