Can a little electrical stimulation help people learn quicker? And how would technology that does this be used? And why would you want to use this over medicines?
Professor Roi Cohen Kadosh describes a phenomena that they’ve noticed where giving people a little electrical stimulation to the scalp appears to help people learn things quicker; and rather than using this to make super-geniuses, could this be used to help people with learning difficulties? Roi discusses how it might work, and discussed the moral and ethical implications of such a technology. From Oxford Sparks.
In this video Roi Cohen Kadosh (Professor of Cognitive Neuroscience at the University of Oxford) likens the use tDCS without a task and purpose, to an athlete taking steroids and not exercising. He discusses recent papers coming out of his lab and describes the research that resulted in this paper: Combining brain stimulation and video game to promote long-term transfer of learning and cognitive enhancement. Kadosh points out that while tDCS did enhance performance in a math challenge, it simultaneously had a negative impact on another. Following Kadosh, Dr Hannah Maslen discusses DIY and DTC tDCS in the context of regulation in the EU.
Those who received real tDCS performed significantly better in the game than the sham group, and showed transfer effects to working memory, a related but non-numerical cognitive domain. This transfer effect was absent in active and sham control groups. Furthermore, training gains were more pronounced amongst those with lower baseline cognitive abilities, suggesting the potential for reducing cognitive inequalities. All effects associated with real tDCS remained 2 months post-training. Our study demonstrates the potential benefit of this approach for long-term enhancement of human learning and cognition.
Despite thousands of studies, there remain many mysteries. Most studies involve extremely short experiments with few participants, and they often assess results after just a single session, using very specific tasks. That means results are not generally applicable to real-life situations or to all people. And nobody knows what the consequences might be of frequent use for long periods of time, which is how many people would like to use tDCS.
There is plenty of optimism that tDCS will eventually have real, even transformative applications. But that time does has not come. “At the moment, I don’t know about any protocol or device for which we could really say you could use for gaming or everyday tasks and it would improve performance and there would be no risks with it,” Nitsche says. “My advice would be to be cautious.”
The device did seem to work on some level. For 15 minutes, I experienced a light pressure on the side of my forehead while the electrodes delivered pulses. Toward the end of the session and for about an hour afterward, my brain was definitely down a notch. However, I wouldn’t describe the feeling as zen so much as vaguely stoned. This is apparently not unusual, as one of the company’s publicity reps, Mark de la Vina, told me that it makes a small percentage of users feel high. I felt a pleasant, light floatiness and noticed myself typing and speaking more slowly.
The sensation was something I could definitely get used to — although I won’t be swapping out my meditation practice for a vibe session anytime soon.
“People seek to relax … in different ways,” said Dr. Judy Iles, a University of British Columbia neuroethicist. “But why it is better or safer than exercise, meditation or fresh air or other healthy lifestyle behaviors is not evident.”
The bottom line? Early adopters are essentially part of an experiment. Casual users might replace the evening cocktail with an occasional zap, but until more research is done, you’d be wise to think twice before replacing your morning coffee with a jolt to the head.
Katie, 23, has suffered from anxiety and depression since she was 18. When her boyfriend Lee told her about transcranial directcurrent stimulation (tDCS), a form of neurostimulation which involves administering a low level of electrical current to the brain, she was sceptical. But Lee had heard that it could help people with mood disorders and wondered if she might benefit from it.
“The first time, I freaked out,” she remembers. “I thought, ‘I can’t cope with putting electrical stimulations in my brain.’ Lee put this machine on and, it’s difficult to explain, but, everything went empty in a good way. I can’t remember if I’ve ever felt like that. I felt relaxed and chilled inside. It was a mad sensation and an out-of-body experience.”
She’d tried anti-depressants in the past but found they didn’t work for her. Now she uses the kit regularly. “It’s improved my life and improved my mind,” she says.
It is the rare human who doesn’t wish to change something about his or her brain. In my case, it’s depression, which runs on both sides of my family. I’ve been taking antidepressants for almost twenty years, and they help a lot. But every couple of years the effects wear off, and I have to either up the dose or switch to a different drug—neither process can be repeated indefinitely without the risk of liver or kidney damage. So although my symptoms are under control for now, I worry, depressively, about what will happen when I exhaust the meds. As I was researching this piece, my attention was caught by a number of randomized controlled trials showing a benefit from tDCS for depression. (The data are insufficient to allow definitive conclusions, but larger trials are in progress.) I was almost embarrassed by how excited I felt. What if it was possible to feel less sad—to escape the deterministic cycle of sadness? What if you could do the treatment yourself, at home, without the humiliation and expense of doctors’ visits? I asked Vince Clark whether any private physicians use tDCS outside of a research setting.
Very well researched and well-balanced article from Mark Harris at The Economist.
Hardly surprising, then, that DIY brain hackers want in on the action. Christopher Zobrist, a 36-year-old entrepreneur based in Vietnam, is one of them. With little vision he has been registered as blind since birth due to an hereditary condition of his optic nerve that has no established medical treatment. Mr Zobrist read a study of a different kind of transcranial stimulation (using alternating current) that had helped some glaucoma patients in Germany recover part of their vision. Despite neither the condition nor the treatment matching his own situation, Mr Zobrist decided to try tDCS in combination with a visual training app on his tablet computer. He quickly noticed improvements in his distance vision and perception of contrast. “After six months, I can see oncoming traffic two to three times farther away than before, which is very helpful when crossing busy streets,” he says.
Equally troublesome is a meta-analysis of the cognitive and behavioural effects on healthy adults that Mr Horvath subsequently carried out. As before, he included only the most reliable studies: those with a sham control group and replicated by other researchers. It left 200 studies claiming to have discovered beneficial effects on over 100 activities such as problem solving, learning, mental arithmetic, working memory and motor tasks. After his meta-analysis, however, tDCS was found to have had no significant effect on any of them.
If tDCS alters neither the physiology of the brain nor how it performs, thinks Mr Horvath, then evidence suggests it is not doing anything at all. Marom Bikson, a professor of biomedical engineering at City University of New York, disagrees. “I can literally make you fall on your butt using the ‘wrong’ type of tDCS,” he says. Dr Bikson thinks the biggest challenge for tDCS is optimising techniques, such as the dose.
Roi Cohen Kadosh is a leading non-invasive brain stimulation researcher. (Also elsewhere on the blog)
A new line of research opens the possibility of modulating and enhancing human cognition using mild and painless transcranial electrical stimulation (tES), which includes transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS). Such initial findings trigger excitement as well as scepticism. The current review aims to provide a guideline for those who are interested in expanding their research into this field. I will therefore discuss: (1) the principles of tES and its putative mechanisms; (2) its potential to modulate and enhance cognitive abilities; (3) the misconceptions on which scepticism about this method is based; and (4) possible directions for the advancement of this field in which psychologists in general and cognitive psychologists in particular should in my view play a key role. I will conclude that this nascent field, which has been neglected by psychologists, requires their contribution in order to lead to basic and translational advancements on human behaviour.
And another excerpt around the hot topic of ‘transfer’… Basically, that it’s difficult to measure (positive effects of stimulation leading to enhanced intelligence) when we’re not even sure what cognition means.
Another closely related issue in cognitive enhancement and training is the issue of transfer (Taatgen, 2013). Currently, there is mixed evidence from tES-paired training studies of transfer of tES-training benefits to another task. One of the issues regarding this lack of consistency is the difficulty of selecting appropriate training and transfer tasks, and this in my view is often due to a difficulty in identifying which cognitive functions and brain regions are activated by the specific training material. In other words, the constraint might not be due to the limited potential of tES to induce transfer, but due to suboptimal experimental design. This drawback is not limited to tES, but is a generic problem in the field of rehabilitation and cognitive enhancement (Cohen Kadosh, 2014). Indeed, some studies have shown that tES can even further increase the chance of transfer in paradigms that have struggled to show transfer without stimulation (Cappelletti et al., 2013; Looi, Duta, Huber, Nuerk, & Cohen Kadosh, 2013). Further studies are needed to examine the multifaceted issue of transfer effects, and their possible enhancement using tES. However, in order for such knowledge to progress, a better understanding of the cognitive mechanisms involved is necessary (Taatgen, 2013).
Zap goes the effect
The team pooled the results of more than 400 studies that reported a change in cognitive skills following a session of tDCS.
“Most studies have more than one outcome measure, such as accuracy, speed, errors made and so on,” explains Horvath. And while one study may show, for example, improved accuracy on a memory task after tDCS but no effect on speed or errors, another memory study may show improved speed, with no effect on accuracy or errors. When put together they cancel each other out. This pattern played out in studies of memory, processing speed and mathematical ability, Horvath found.
Roi Cohen Kadosh, a neuroscientist at the University of Oxford who has studied the effects of tDCS on mental arithmetic, is far from convinced by this argument. “My feeling is that it is very premature to do what they did,” he says. “They did have a large sample size, but they fractured it so that they are comparing the results of three or four studies and expecting to see something meaningful. It’s the easiest thing in science to not find results,” he says.
They found that participants with high maths anxiety made correct responses more quickly and, after the test, showed lower levels of cortisol, an indicator of stress. On the other hand, individuals with low maths anxiety performed worse after tDCS.
“It is hard to believe that all people would benefit similarly [from] brain stimulation,” says Cohen Kadosh. He says that further research could shed light on how to optimise the technology and help to discover who is most likely to benefit from stimulation.
Depending on where he puts the electrodes, Whitmore says, he has expanded his memory, improved his math skills and solved previously intractable problems. The 22-year-old, a researcher in a National Institute on Aging neuroscience lab in Baltimore, writes computer programs in his spare time. When he attaches an electrode to a spot on his forehead, his brain goes into a “flow state,” he says, where tricky coding solutions appear effortlessly. “It’s like the computer is programming itself.”
Whitmore no longer asks a friend to keep him company while he plugs in, but he is far from alone. The movement to use electricity to change the brain, while still relatively fringe, appears to be growing, as evidenced by a steady increase in active participants in an online brain-hacking message board that Whitmore moderates. This do-it-yourself community, some of whom make their own devices, includes people who want to get better test scores or crush the competition in video games as well as people struggling with depression and chronic pain, Whitmore says.
Felipe Fregni, an associate professor at Harvard Medical School who was involved with the research, has a theory on why that happened. “The students ingested fewer calories because they could make more rational decisions,” he says.
He says tDCS may have dialed up the activity in the students’ prefrontal cortices—where the stimulation was applied and where they make rational, considered decisions, which in turn dialed down the students’ initial knee-jerk reaction to eat food when they saw it. This makes good sense: The dorsolateral prefrontal cortex is known to be an area of the brain that enables us to inhibit temptation.
“It’s the part of the brain most developed in humans compared to monkeys, and it relates to some of the more advanced abilities we have,” says Roi Cohen Kadosh, a neuropsychologist at the University of Oxford who is another of the leading lights in tDCS research. “It’s involved in learning and working memory, and it’s highly connected to other brain regions, such as ones involved with addictions and rewards, and food is rewarding.”