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Transcranial Direct Current Stimulation: Fundamental enhancement for humanity?

The idea of a simple, cheap and widely available device that could boost brain function sounds too good to be true.

Yet promising results in the lab with emerging ‘brain stimulation’ techniques, though still very preliminary, have prompted Oxford neuroscientists to team up with leading ethicists at the University to consider the issues the new technology could raise.

Recent research in Oxford and elsewhere has shown that one type of brain stimulation in particular, called transcranial direct current stimulation or TDCS, can be used to improve language and maths abilities, memory, problem solving, attention, even movement.

Critically, this is not just helping to restore function in those with impaired abilities. TDCS can be used to enhance healthy people’s mental capacities. Indeed, most of the research so far has been carried out in healthy adults.

More details from Oxford Press Release

My Comment:

This research cuts to core of humanity: the capacity to learn. The capacity to learn varies across people, across ages and with illness. Enhancing the capacity to learn of children and adults, with impairments and without. The ability to learn is a basic human good. This kind of technology enables people to get more out of the work they put into learning something.
This is a first step down the path of maximizing human potential. It is a very exciting development. We need to control the release of the genie. Although this looks like a simple external device, it acts by affecting the brain. That could have very good effects, but unpredictable side effects. We should aim to do better than we have with the development of pharmaceuticals. We should learn from our mistakes over the last forty years.
Of course, as with any powerful technology, not only is there the possibility of great benefit, there is potential for misuse and abuse. This has been used in other experiments to improve ability to lie.

At this stage, we need more research to understand better the risks and benefits, in specific populations, in real life. Any regulation should prevent misuse and abuse, but facilitate good research. This kind of technology good be as important as the internet and computing. Those are external cognitive enhancements. This is basic fundamental cognitive enhancement.
This technology overcomes some standard objections to enhancement. It is not a set of cheat notes. You require effort and hard work to learn. It is just that you get more out of your effort.
And because it is cheap, low tech, easily affordable, it could be widely available. This addresses the objection that it will introduce inequality and unfairness. It could be available and should be available to all, if it is safe and effective.
What is the ethical way forward? More research before deployment. It is promising but not proven at this stage.

The issues were discussed this morning on the Today Programme , where Barbara Sahakian said that it should not be tested on young children because the risk/benefit profile was too high. I disagree. As we say in the paper, it may have different effects in normal young children to those with impairments. So we can’t extrapolate safety or efficacy from studies in impaired children or adults. We simply won’t be able to predict whether it is beneficial in normal kids without doing the experiments. 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. These won’t have disease or disorder but they may be relatively disabled by their lower capacity to learn. That is where I would start: kids who are at the lower end. See my blog on Lethal Ethics for elaboration of this kind of point.

This is liable to the objection that lower functioning children are being used as guinea pigs. If we find it is safe, it could be rolled out to higher functioning children. I have some sympathy with this egalitarian concern. Perhaps those who stand to benefit and use it should participate in the research. If we envisage it as a general educational aid, it is reasonable in one way that all groups of children contribute to the research.

 For a full discussion see Cell Biology Article   

Oxford University Science Blog


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15 Comment on this post

  1. Am I right in thinking that (a) TDCS has been trialled on young adults and (b) the brains of young adults are still developing (though the presumably the changes are less drastic than the changes of young children)? Barbara Sahakian complains that "I don't think we know enough about the long-term safety of these techniques to justify using them on the developing brains of children", even though the potential of the technique justified using them on the developing brains of young adults.

    So rather than jumping straight to do trials on young children, surely older children should be the next stage of research? If 18-25 year olds haven't suffered any adverse consequences, then see if 16 and 17 year olds are willing to be trialled on. Their brains will be slightly less mature than 18 year olds, but not significantly so. Then if these trials work out, progress to 14 and 15 year olds, and so on…

  2. I would like to see how i might enroll my son (who has high functioning autism) in a potential study for documenting learning possibilities. Please put me on a contact list if it available. We are very interesting in this asap. Time is of the essence for these children. @Matt. I disagree. Developing brains should be the immediate focus if this could be a hope for these children.

      1. Not at all. Because he is high functioning, his issues are really about understanding social cues. He has a delayed ability to learn because he got behind as we all tried to figure out the diagnosis – he didn't have the right learning environment right away which i have nothing but regrets. Schools are not equipped for these kids….he is behind on reading and math. I believe that the social cue stuff we can cope with. but the academics….we must do something in order to prepare him for adult hood and if this could help that…then my gosh, i can't imagine why we wouldn't try. So he can go to college! and compete with others!

  3. Krista I passed your comment on to Roi. Matt, I am not sure that starting with older children avoids the problem – though this is a scientific issue. We need to know whether the populations are relevantly similar or relevantly different, in which case safety and efficacy data won't translate across groups. Your proposal that we move down the age groups in small steps is interesting and might overcome this, if feasible practically

  4. Professor Karin Lesnik-Oberstein

    I am alarmed and saddened to see exactly the kind of hopeful responses from caring parents and individuals with certain learning difficulties to this kind of unethical research claims. Of course any suggestion that a 'brain stimulus' can improve learning is going to give hope to people who find themselves or their children under pressure of some kind to find such improvement. Any ethical reseracher would have gone out of their way to make clear their are still profound scientific questions which make this kind of claim extremely problematic and unlikely. Not just, as Matt Sharp rightly points out, that it might precisely exacerbate the very conditions it might seem to hold out promise for, but, as much research points out, there are still serious and crucial questions about the very diagnostic criteria for, for instance, both autism and ADHD (mentioned above). Both these diagnoses, just to begin with, rely on descriptions of clusters of symptoms, for instance, not on known biological or psychological mechanisms or causes. Even within such theories themselves, Matt Sharp's point would be valid: there are theories, for instance, that both autism and ADHD have to do with a lack of a barrier to external stimuli in the brain, in which case it would certainly be a risk that any further stimulation would be potentially counter-productive.

    Never mind further fundamental problems around what constitutes 'cognition' at all…

    I would warn people not to cling to hope from research presented in such an inherently unethical and careless manner: the fact that these researchers are even jumping from highly speculative experimental work to themselves suggesting working on children at all (never mind children with learning difficulties of whatever kind) should set all alarm bells ringing in and of itself.

    Yours sincerely,
    Professor Karin Lesnik-Oberstein, Director of the Centre for International Research in Childhood: Literature, Culture, Media, University of Reading

  5. Thank you for this good dose of common-sense, Karin.
    Anyone who has read Siddhartha Mukherjee's wonderful book on cancer ("The Emperor of all Maladies") will recognise the high risk of appalling consequences in making premature announcements of "breakthrough" remedies, both on patients and their loved ones.

  6. Transcranial direct current stimulation is being studied in children. Just off the top of my head, I am aware of: 1) a study in children with schizophrenia documenting the safety of tDCS, 2) a study documenting improvement for childhood-onset epilepsy utilizing tDCS and 3) an unpublished and on-going study using tDCS to improve language in severly autistic children.

    For perspective, 500 studies using tDCS demonstrate insignificant side effects. tDCS causes only temporary effects, providing additional safety.

    Assuming the continued safety record of tDCS, I would hope for facilitated research and availability for those who could benefit.

  7. @ Professor Karin. Thanks for your concern – i think its important that researchers have the highest standards of ethics. But what i was reacting to when i sent my interest was in fact, news that this research is showing positive results with little side effects. I also thought about Harrison Bergeron when i read this original article. But the benefits outweigh the risks. Our society is very cruel in its own way and I want my children to be set up for success just like everyone does. @Dr. Fugedy – i wonder about whether this is being study to be used in patients with advanced dementia….curious.

    1. tDCS has demonstrated benefit for Alzheimer's and Parkinson's patients. Appreciate that tDCS enhances neuroplasticity -nerve connections, which are constantly being formed and account for memory and learning. The greater the pathology, the less tDCS can compensate. I wonder if brain enhancement could be preventative for dementia.

      I also wonder if can tDCS be considered an electrical environment conducive to learning. tDCS doesn't replace study, but enhances the results of study. How could I be against safely enhancing my children's ability to study? The answers will result from scientific and ethical considerations. is a wonderful search engine. Simply insert search terms (such as tDCS, ADHD) and you will be provided abstracts of every scientific study published.

  8. Having tried quite a range of medication for depression and ADHD, several of which have had fairly miserable, albeit apparently non-serious side-effects, I'm really very keen to hear about successful early indications for new, particularly non-drug, treatments. The reported benefits of tDCS on memory and activation are of pretty great interest to me. The drugs haven't worked, I'm hoping something else does. I'm not about to strap my head to a car battery, but I'm willing to be right there at the front of the queue if it helps find a new and effective way of overcoming some of the negative aspects of ADHD. I don't think this makes me naive.

  9. Me too. My mother is a neuropsychologist and often deals with with ADHD cases – she works with learning disorders. If there are conclusive alternative methods, – or at least more conclusive than drugs-, I am sure they would be very useful. In this sense, any links to related articles you might have would be greatly appreciated.

      1. Thanks, it didn't occur to me to use Pubmed. However, an initial, simpler search found only three articles, which in their turn deal only tangentially with ADHD.

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