Whether or not your mobile phone is harmful to your health has long been the subject of debate. It's been speculated that frequent and lengthy mobile phone use may cause brain tumours. Now a new study has shown that brain activity is affected, with mobile telephony actually slowing it down, according to PCworld.com.

The study results, published in this month's International Journal of Neuroscience, are based on a study of 300 people over two years. The British, Australian and Dutch scientists involved in the research now want to expand the study to 17,000 people over a longer period of time.

Minor difference

According to the findings, those who used their mobiles a lot had lower brain activity. However, the difference was minor and fell within the frame for normal deviations. Whether the affect was caused by mobile phone use or just a coincidence will be looked at, if the study is expanded.

The 300 participants included 100 people who used their mobile occasionally, 100 who didn't use one at all, and 100 people who used their handset a lot.

The researchers used EEG (electroencephalography), a technology that measures the electrical activity in the brain. Some functions, such as focusing attention, were actually enhanced - although the overall activity was down.

The increase in focused attention was described as a learning effect. It has been suggested that those who make lots of phone calls have learned to filter out background noise and other distractions when using their mobiles on public transport and in other public places.