Neuromodulation: could it improve education?
By Roi Cohen Kadosh, Wellcome Research Career Development Fellow, University of Oxford.
Harnessing neuroplasticity for education using neuromodulation
I like movies. One of my favourite scenes is in “The Matrix” where the hero, Neo (no relationship to the cortex), took a short nap while a plug was inserted into the socket at the back of his head. A few seconds later, Neo woke up and said, “I know Kung Fu!” What a lovely idea! It would be much easier to learn maths, languages, and just to upload all the articles and books that I have not yet been able to read. Unfortunately, this remains as science fiction, and depending on the subject or type of learning it can take days, months, and even years of intensive labour. In the case of those with learning difficulties, such efforts do not improve their performance as they may in other people. My aim is not to invent a machine like the one Neo used, but to make a smaller step by examining the possibility of modulating neuronal activity in the brain whilst people are learning a skill and subsequently using it. Still, to the non-expert reader, it does sound like science fiction, and one of the questions that I was asked four years ago during my interview at the Wellcome Trust was if this idea is indeed feasible. In this blog I introduce the neuroscientific principles of the technique that I use in my research and describe the progress so far. I also discuss the work that still needs to be done in our efforts to improve the speed and quality of learning, and thus, educational achievements.
Stimulating the Brain using Electricity: A shocking idea?
The first association that comes to mind when electricity and brain stimulation are mentioned is electroconvulsive therapy (ECT) in which strong electrical current is induced in anaesthetised psychiatric patients for therapeutic effect. This is not what we are doing. Rather, my lab is using a technique called transcranial electrical stimulation (tES), in which we apply a small electrical current (for example, 1milliAmp, or one thousandth of an Ampere) to the scalp to modulate neuronal activity during training in order to enhance learning and high-level cognitive functions. The current is generated from a low power source, such as two AA batteries, and is delivered to the scalp using one or more electrodes.
Our research is supported by more basic research in neuroscience, in which animal studies have shown that low electrical currents can affect neuronal excitability and make it either easier or harder for neurons to fire (Bindmann, et al., 1964). More recently, research has shown that this is safe and effective in humans (Paulus, 2013; Cohen Kadosh, 2013). By employing mostly basic tasks that have little to do with education, this early research has shown that it is possible, for instance, to aid finger movements (Nitsche & Paulus, 2000) or help the brain to detect motion more accurately (Antal, et al., 2004).
Animal studies have shown that this low level of electricity can enhance the secretion of a growth factor (brain-derived neurotrophic factor) which is crucial for synaptic learning (Fritsch, et al., 2010). Furthermore, in humans, the modulatory effect of tES affects regional levels of neurochemicals (gamma-aminobutyric acid and glutamate) that are involved in learning, memory, and neuroplasticity (the brain’s ability to change in response to new experiences or learning; Stagg, et al., 2009). In line with these findings, some studies have shown that tES in combination with training can improve motor skills acquisition (Reis, et al., 2009).
This research led to a great deal of hope for rehabilitative applications of tES, mainly in rehabilitation of those with acquired neurological damage, such as stroke patients, or degenerative illnesses (Cohen Kadosh, 2013). However, I envisage that this tool can be used to improve educational outcomes, such as learning of maths, or other functions that are critical for optimum educational outcome, such as literacy, working memory or attention (Kraus & Cohen Kadosh, 2013; Cohen Kadosh, et al., 2013).
Such an approach—to modulate neuronal excitability whilst people are learning, inducing physiological changes and harnessing neuroplasticity—is, in my view, one of the most exciting synergies between neuroscience and education. We are not only examining the neural correlates of learning or cognitive skills, but rather we are affecting the brain to increase learning outcomes in a given cognitive area. In the next section, I will describe some results from my lab, which focus mainly on one of the most sophisticated human abilities: mathematical cognition.
We chose to work on mathematical abilities for three main reasons:
1. Maths cognition involves a complex system and affecting it may be more relevant to people than simpler abilities such as finger movements.
2. Maths is one of the most neglected fields of research, compared to attention, memory, and literacy, say. This is unfortunate, as in the 21st century, mathematical achievement is one of the foundations of a thriving society. Approximately 20 per cent of people have low numeracy skills, and 3-13 per cent of the population are considered to have a more serious, specific disability with numbers (e.g., developmental dyscalculia, or mathematical learning disability). Numerical difficulties are linked to lack of progress in education, increased unemployment, reduced salary and job opportunities, and additional costs in mental and physical health (Duncan, et al., 2007; Parsons & Bynner, 2005; Gross, et al., 2009). Furthermore, the effects of numeracy skills expand beyond the life of an individual and affect society in general (Gross, et al., 2009).
3. Currently, only behavioural interventions have been used to improve mathematical abilities in maths. A better approach would be to combine behavioural training together with a method that will “prime” the brain regions that are involved in the skill, in order to facilitate the brain in consolidating the information and in processing it more efficiently (Reis, in press).
So far, we have carried out studies that include more than 1,000 sessions of tES combined with cognitive training. The sessions mostly involved mathematical training of university students (e.g., learning the quantity conveyed by different symbols, learning to calculate using an algorithm, or via arithmetic fact retrieval). To date, we have found mostly positive effects, indicating that stimulation to brain regions that are involved in mathematical cognition and learning can improve the learning and subsequent performance (Cohen Kadosh, 2010; Iuculano & Cohen Kadosh, 2013; Snowball, et al., 2013). One of the important findings is that the effect of the stimulation is long-lasting. More specifically, we found that compared to placebo stimulation, when brain stimulation is applied during training to relevant brain regions, it leads to improvements that last for up to six months. While the current findings in each study are based on relatively small sample sizes, findings have been replicated in four different studies, including one carried out by another group, with our help (Cappelletti, et al., 2013).
Another important issue is the possibility of side effects. TES seems to be safe in terms of physical side effects; we have not encountered any major or minor safety incidents such as induced seizure, burning to the scalp or dizziness in any of our studies. Most of our subjects cannot feel the stimulation and cannot tell whether they received real or placebo stimulation. However, little attention has been given to the cognitive side effects; that is, whether enhancing one ability is achieved at a cost to another. While we found evidence for such trade-off in one study (Iuculano & Cohen Kadosh, 2013), we did not find it in others using different types of stimulations. Nevertheless, potential cognitive side effects are one of the important points to keep in mind in order to optimise tES for successful, safe and beneficial neuroenhancement.
All together, the current results indicate that it is possible to improve mathematical learning and subsequent performance in young, typically developing adults. We know that many people struggle with maths during school and afterwards. We receive many e-mails from interested individuals who would like to use this technique in order to improve their maths abilities or their children’s low numeracy skills.
In order to shed light on the efficacy of this approach with those with learning difficulties, we are now running a small scale study in a London school tailored for those with specific learning difficulties (Fairley House). The training is conducted in school, using a maths video game that we designed based on neuroscientific, psychological, and educational principles, and we are working with the motivated team there to examine the potential of TES to enhance the abilities in those who need it the most. So far, the children seem to enjoy the training and there are no complaints about the stimulation. However, a larger scale study will be necessary in the future. Once we run all the required studies to determine the best stimulation parameters, efficacy, safety, and the potential operating mechanism, it will be a straightforward process to integrate this tool in a full scale trial, in several sites and countries.
Promises and Perils
TES has been used to a very limited degree with children. The studies in these cases were on children with severe developmental disorders such as autism (Schneider, et al., 2011) or schizophrenia (Mattai, et al., 2011). It is unknown currently what effects tES may have on the developing brain. On the one hand, it might be that tES at a stage where the brain is more amendable to changes will lead to even more optimal results. On the other hand, it might lead to unexpected side effects by modifying intact brain functions. In addition to the unknown effects on children, tES brings a question of neuroethics.
The current results indicate that it is possible to improve learning in those with average abilities. However, it is unknown how the efficacy of tES is modulated by individual differences. Is it more efficacious in those with lower abilities, or higher abilities? If the latter, it might lead to increase in the cognitive gap between those populations.
We have yet to understand the exact mechanisms that are involved in the current methods of cognitive enhancement, especially when applied to children. Neuroscientific knowledge in this area will allow us to assess the potential risk, if applicable, and to allow for safer stimulation.
Keeping these limiting factors in mind, the potential benefits of applying this area of neuroscience to education is large. The possibilities of improving the speed and quality of learning and subsequent performance could mean improving cognitive achievements in those with atypical development, those with average abilities, and even those at more advanced ages, who would like to acquire new skills. Ultimately, this means improving the quality of life, career prospects, and self-esteem of large groups of people, and shortening the burden of long and tedious behavioural interventions.
While the current results are promising, there is room for future development. For example, the current findings show the feasibility of tES in maths learning. It would be desirable to assess the feasibility of tES to improve other domains such as literacy, attention, and working memory. While some effects have been noted in adults (Sela, et al., in press), there is no record of effects longer than six months, and no research at the moment on children who experience difficulties in these domains. While it is unlikely at the moment for people to learn French, algebra, or Kung Fu as quickly as Neo, a successful advancement in this field will allow a method in which people will be able to enhance their learning and cognition in a safe and easy manner in and outside the classroom.