Have you ever caught a whiff of freshly baked bread, or spotted a gooey chocolate brownie, and instantly been hit with a craving?
Do you run to the shops to buy yourself a treat, or just walk away and carry on with life?
Your response to food is a key part of eating behaviour, and your brain is an important hub for controlling these responses. By interpreting signals from our body, our brain directs us to eat (or stop eating) to maintain our energy needs. But eating goes beyond mere energy requirements – eating is often a social activity, and foods are a source of pleasure and reward. Our brain is able to incorporate these different factors to drive and control our eating behaviours. However, in the current environment, where we are constantly bombarded by food cues (such as the smell and sight of tempting food), it can be difficult to control our eating behaviour.
Data suggests that for some individuals, there is reduced activity within certain areas of the brain that are important for controlling eating behaviour and particularly for preventing impulsive actions associated with overconsumption (e.g. binge eating). This means it is even more difficult to control the response to food and related cues, and we know that people respond differently to the rewarding components of food with some individuals experiencing heightened reward sensitivity. This means these individuals find it particularly difficult to walk away from tempting foods, which often leads to the consumption (or overconsumption) of these highly rewarding, high-calorie foods.
That’s where our research comes in!
Our research looks to change how people respond to food and food-related cues. Specifically, we are looking to alter eating-related measures (e.g. in-the-moment food craving) using transcranial direct current stimulation (tDCS), a form of non-invasive brain stimulation where a weak electrical current is passed through the brain via electrodes placed on the scalp.
You want to do what, to my what?!
Electric currents + your brain = nasty One Flew Over the Cuckoo’s Nest vibes, but it’s not what you think.
The electric current is very weak, usually up to 2.0 milliampere (mA). To give some context, electroconvulsive therapy (as seen in One Flew Over the Cuckoo’s Nest) uses electric currents of up to 900 mA. At 2.0 mA, you’re likely to feel a little tingling or itching, but research on the safety of tDCS shows no damage to either the skin or brain tissue, and the technique is widely considered safe for children and adults, as well as healthy individuals and patient populations. (However, do note the ‘do not try this at home’ message at the end of the blog!)
While the technique may seem a little elaborate, the equipment is relatively simple – it involves two conductive rubber plates (electrodes), housed inside saline-soaked sponge pads, which are connected to a stimulation device powered using 2x AA batteries. To hold the electrodes in place, you wear a (very flattering) elasticated cap – modelled by yours truly above. That is as exciting as the equipment gets. During stimulation, you’re usually asked to remain seated and relaxed, but can also be asked to complete a computer-based task or watch a short video.
But, what does it actually do?
The brain is like a packed room, with people (neurons, or nerve cells) constantly chatting to each other (sending chemical signals called neurotransmitters). This chatting, or the passing of neurotransmitters from one neuron to the next, is how the brain tells our body to perform certain functions, and is important for driving our behaviour. Through tDCS, we are able to increase or decrease the amount of chatting that occurs, and as such the level of activity within certain parts of the room.
This becomes important where we see low activity in some areas of the brain, such as those that help control our eating behaviours, which contributes to “problematic” behaviour. Through tDCS, we are able to alter brain activity, learning, task performance and behaviour.
The miracle cure for obesity!
Well, not quite. Obesity and eating behaviour are incredibly complex – although the techniques show promise for altering our response to food and food-related cues in some populations (such as those with binge eating behaviour), we’re a long way from testing the efficacy as a tool for obesity treatment. To fully determine the role tDCS may play in altering eating behaviours, and the potential use of this technique for weight management, we need to carry out many (many) more studies. As such, we’re in constant need of participants…
We need your help!
Share your views on non-invasive brain stimulation (NIBS) techniques.
Whether you’re a tDCS pro, or just hearing about brain stimulation for the first time, we’re looking for individuals over the age of 18 to share their thoughts of these techniques. Simply fill out this short survey around the perceptions of tDCS and other forms of NIBS.
On completion of the survey, you have the opportunity to be entered into a free prize draw to win one of three £50 vouchers.
If you would like to find out more about our research, or you would like to participate in one of our other studies, you can email me via firstname.lastname@example.org.
An important note…
Please do not try this at home. tDCS procedures within research and clinical settings are rigorously controlled and meticulously monitored to ensure the protocols are safe and ethical. Do-it-yourself (DIY) tDCS can lead to some worrying side effects (e.g. headaches, skin burns, persistent metallic taste) due to the use of unregulated devices and settings beyond safe limits. tDCS should always be delivered by a trained professional.
About the author
Jordan Beaumont (@JordanDBeaumont) is a Registered Nutritionist and Associate Lecturer in Food and Nutrition at Sheffield Hallam University. He is also a PhD candidate and Visiting Lecturer at Leeds Trinity University. The research discussed in this blog was conducted at Leeds Trinity University, under the supervision of Dr Martin Barwood, Dr Danielle Davis, Dr Michelle Dalton and Professor Mark Russell.