According to a recently published study, mobile phone users who use their phone frequently demonstrated slowed brain function. However researchers also found that frequent mobile phone users showed better focused attention, which can be explained as a learning effect related to making more phone calls in distractive surroundings.

Scientists are quick to say that no firm conclusions can be drawn as to whether these effects are to be considered an adverse health effect or not, but data have already been collected from more than 20.000 people to replicate this study and further investigate the adverse health effects.

In the study published in the September issue of the International Journal of Neuroscience researchers analyzed 300 people of which 100 were 'frequent mobile phone users', 100 'non-mobile phone users' and an 'intermediate group' of 100 people. Differences in brain activity (measured using QEEG or quantative EEG), Neuropsychological functions such as attention, memory and executive function and personality traits were assessed.

According to the results frequent mobile phone users score higher on extraversion - probably a cause rather then an effect. Furthermore, frequent mobile phone users showed improved focused attention.

"In Alzheimer's dementia you also find a severely slowing of brain activity. However, the slowing found in this study, with mobile phone users, can still be considered within 'normal' limits" according to Martijn Arns, the main investigator.

Analysts say this could be a result of the learning effect due to making more phone calls in busy environments, whereby people learn to focus better on the phone call and filter out irrelevant environmental information.