After all the concern over possible damage to health from using mobile phones, scientists have found a potential benefit from radiation.
Their work has been carried out on mice, but it suggests mobiles might protect against Alzheimer's.
Florida scientists found that phone radiation actually protected the memories of mice programmed to get Alzheimer's disease.
They are now testing more frequencies to see if they can get better results.
The study by the Florida Alzheimer's Disease Research Centre is published in the Journal of Alzheimer's Disease.
Genetically altered mice
It involved 96 mice, most of which had been genetically altered to develop beta-amyloid plaques in their brains, which are a marker of Alzheimer's disease, as they aged.
The rest of the mice were non-demented.
All the mice were exposed to the electro-magnetic field generated by a standard phone for two one-hour periods each day for seven to nine months.
The memory benefits of phone exposure took months to show up, suggesting that a similar effect in humans would take years.
The researchers conclude that electro-magnetic field exposure could be an effective, non-invasive and drug-free way to prevent and treat Alzheimer's disease in humans.
They are currently testing whether different sets of frequencies and strengths might produce a more rapid and greater cognitive benefit.
Chuanhai Cao, another author of the study, said: "Since production and aggregation of beta-amyloid occurs in traumatic brain injury, particularly in soldiers during war, the therapeutic impact of our findings may extend beyond Alzheimer's disease."
The authors say previous studies have linked a possible increased risk of Alzheimer's with "low-frequency" electro-magnetic exposure like the energy waves generated by power and telephone lines.
They say mobile phones emit "high frequency" electro-magnetic waves that are very different because they can have beneficial effects on brain function, such as increasing brain cell activity.