Wednesday November 16 2011
None of the teenagers studied was addicted to gaming
“Teenage video game players have brains ‘like gambling addicts’,” reported the Daily Mail. Covering the same research, The Daily Telegraph warned that “children’s brains could be hardwired to spend hours playing video games”.
These headlines are based on a small study of 154 healthy 14 year olds comparing the brain structure of those who played video games more than nine hours a week (frequent gamers) with those who played less (infrequent gamers). They focused on an area of the brain associated with rewards and decision-making (the ventral striatum) and found that a proportion of this area (the ‘grey’ matter, made up of nerve cells) was larger in frequent video game players.
Contrary to the headlines, this study did not compare the brain structures of gamblers with those of frequent video game players. However, the researchers did discuss the possible, but unproven, theory that there were similarities between the brains or reward systems of gamblers and frequent gamers.
This study was also unable to establish whether the brains of frequent gamers are different because they play games, or whether their brains were naturally different to begin with and this made them more likely to be a frequent gamer.
Where did the story come from?
The study was carried out by a large collaboration of researchers from European and Canadian universities and was funded by the European Community’s Sixth Framework programme, the UK Department of Health and a Medical Research Centre programme grant. The study was published in the peer-reviewed science journal Translational Psychiatry.
The Telegraph and Mail focused their reporting on the comparison of computer-gamers’ brains to that of gambling addicts, which was not examined in the research. The BBC News coverage was more measured and reported on the differences between regular and infrequent gamers.
What kind of research was this?
This was a cross-sectional study that used a magnetic resonance imaging (MRI) scanner to compare the brain structure of 14 year olds who were categorised as frequent or infrequent gamers.
The researchers were looking for differences in the size of an area of the brain, called the ventral striatum, known to be associated with reward and decision-making. This area of the brain is also associated with emotional and motivational aspects of behaviour. In particular, it can release a ‘feelgood chemical’ when presented with potential reward situations, such as the opportunity to gain money.
This type of study design cannot establish causal effect, so it cannot prove whether the brains of frequent gamers are different because they play games, or whether their brains were already different and this made them more likely to be a frequent gamer in the first place. A study that assessed brain changes over time would be needed to establish which scenario is correct.
What did the research involve?
Researchers compared the brain structure and function of 154 healthy 14 year olds recruited from secondary schools in Germany as part of a larger Europe-wide study called the IMAGEN project. This sample contained 72 boys and 82 girls.
The children were given a questionnaire that assessed computer gaming activity over a week. The most frequently reported time spent playing computer games was nine hours in a week. The adolescents were then categorised into frequent (over nine hours a week) and infrequent (less than nine hours a week) video game players, for comparison.
The participants’ brains were scanned using MRI. The researchers looked at the amount of two components of the nervous system: grey matter and white matter. Grey matter is mostly brain cell bodies, while white matter mainly contains the brain cell connections that link the grey matter together.
The teenagers were then given tasks to assess reward anticipation and reward feedback behaviour while their brains were scanned using a special ‘functional’ MRI (fMRI) scanner. The fMRI measures small changes in blood flow to parts of the brain. This gives an indication of the areas of the brain that are active during the task.
The teenagers also completed a task assessing gambling behaviour that took place outside of the MRI scanner.
The standard and fMRI scans of frequent and infrequent gamers were compared to look for differences. Researchers took into account the effect of gender, MRI scanner type and whole brain volume in their analysis.
What were the basic results?
The main finding was that the standard MRI scans showed the left ventral striatum of frequent gamers contained significantly more grey matter than infrequent gamers. No differences were found in other brain regions or for white matter.
The researchers then linked the volume of grey matter in this brain region to performance on the gambling task and found that adolescents with higher grey matter volume (the frequent gamers) were faster at making decisions.
They also found that frequent gamers demonstrated higher levels of brain activity on fMRI than infrequent gamers, when they lost during the tasks assessing reward anticipation and reward feedback.
How did the researchers interpret the results?
The researchers say that the larger volume and activity in the left ventral striatum is in line with the theory that the reward system from this region of the brain in frequent gamers may be similar to that at work in excessive gamblers. They also point out that it is not clear whether the differences in the size of the area of the brain are a result of frequent gaming, or whether they were already present and make a person more likely to become a frequent gamer.
This small study analysed a part of the brain associated with rewards and decision-making and showed that the grey matter of this area was larger in frequent video game players compared with infrequent players.
This study did not compare the brain structures of gamblers with those of frequent video game players. The theory that there were similarities between the brains or reward systems of frequent gamers and gamblers was made by the researchers when discussing the possible implications of their findings. These unproven theories brought the story to the news headlines.
The most important limitation of this study is that it cannot establish cause and effect. Therefore, it cannot prove whether the brains of frequent gamers are different because they play games, or whether their brains were naturally different to begin with, and this made them more likely to become a frequent gamer.
A study that assessed brain changes over time would be needed to establish which scenario is correct, and given the huge popularity of video games in the developed world, is long overdue.