I’m someone who when sat in front of a fast food menu will always make a beeline for the most artery-clogging burger and a large fries. At the same time, I’m fascinated by those around me who will happily order “regular” or “small” servings (or even the dreaded “healthy” alternative). How do they resist temptation? What distinguishes these intriguing individuals from the rest of us – and, by the way, where can I get some more of that prized self-control?
I’m not alone. Understanding what self-control is and how it works has fascinated cognitive psychologists for decades, and more recently has led to the idea that perhaps we can harness our knowledge of cognition to temper compulsive behaviours. With over 50 per cent of adults in Europe now either overweight or obese, and numbers rising by 1 per cent per annum, even a modest effect of cognitive training could have major socioeconomic benefits. And that’s not even considering the potential it has for managing other addictions, such as alcohol dependence, smoking or gambling.
Cognitive theories tell us that one way of enhancing self-control may be to change the automatic associations we build throughout our lives between the stimuli around us and our responses. In 2011, Dr Katrijn Houben from the University of Maastricht provided support for this idea by showing that training people to stop simple motor actions to unhealthy foods reduced consumption of those foods in a lab setting. Other studies have shown how this type of training can encourage people to view ‘inhibited’ foods as more negative and less desirable.
So far so good, but there’s a problem: to date, almost all the studies on cognitive control training have relied on artificial settings, where participants do bogus taste tests or other contrived ‘eating tasks’ in the lab. This isn’t so much an oversight of existing work as it is an inevitable limitation within a budding field – before we can test interventions in the real world we need to know how they work under controlled conditions and whether they have any promise at all. But, of course, lab experiments tell us only half the picture. We won’t know if our promising, theoretically motivated interventions have the goods until we unleash them.
|Do you make a beeline for the artery-clogging option?|
Now an ambitious new study by Dutch psychologist Harm Veling and colleagues has done just this, asking whether training has benefits on actual weight loss. Over a four-week period, 113 participants took part in an internet trial in which they could be exposed to different forms of training. One type, called go/no-go training, required them to respond to images of foods but to restrain those responses when they saw palatable, unhealthy foods. Another, called implementation intentions training, relied more on conscious effort, asking participants to rehearse mental rules for avoiding unhealthy eating – for instance, “When I open the refrigerator, I will think of dieting”.
Reassuringly, both methods worked when compared against various control conditions, leading to an average weight loss of about 1 kg per person. The results also revealed some interesting effects of individual differences. Go/no-go training worked best in people with a higher body mass index, whereas implementation intentions were most effective in people who already had strong goals about losing weight. This suggests that by tailoring the training to individual characteristics, we may be able to make it more effective.
Losing 1 kg in a month may not sound like much, but what Veling’s study contributes is a proof of principle that cognitive control training can be taken outside the lab and produce measurable benefits. That alone provides a strong motivation for continuing this line of research, both inside the lab and beyond.
Veling, H., van Koningsbruggen, G., Aarts, H., & Stroebe, W. (2014). Targeting impulsive processes of eating behavior via the internet. Effects on body weight Appetite, 78, 102-109 DOI: 10.1016/j.appet.2014.03.014
Post written for the BPS Research Digest by guest host Chris Chambers, senior research fellow in cognitive neuroscience at the School of Psychology, Cardiff University, and contributor to the Guardian psychology blog, Headquarters.