Happy memories can come flooding back

Too much time on the "moby" is bad for you, right? Cell phone not good for brain cells? Hot spots...killer watts...Hello, darling, I'm on the train...blah blah! But don't bin your mobile phone just yet.

Researchers at the University of Bradford, U.K., have conducted a study revealing that mobile phone use can actually improve the short-term memory of men—but, oddly, not women. Dr. Jim Smythe and Prof. Brenda Costall of the University's School of Life Sciences have carried out an experiment on both the long- and short-term memory of people that were briefly exposed to electromagnetic fields emitted from mobile telephones: 33 male and 29 female students volunteered to be randomly assigned to one of three conditions in the experiment. The students were all right-handed, aged between 18 and 53 years, and of good health with normal hearing and vision.

The findings following the completed study suggest that mobile-phone use may actually enhance cognitive function (memory) in male subjects only and only short-term. "These findings are unique as far as we are aware," concluded Smythe and Costall. "There has not been a suggestion before that mobile-phone effects may be sex-dependent." As yet, they cannot explain the difference in reaction between males and females.

The experiment took place in two phases: the first phase testing the students' ability to learn a series of words and remember them for the short-term, and the second testing how well the students could remember the information a week later.

In the first phase, each student was taken to a secluded room and had to follow a set of instructions given by a research assistant. They were then given an inactive mobile phone, an active mobile phone, or no phone at all. Those students with phones were unaware if they were active or not, and they were asked to hold it to their left ear whilst following the instructions given to them.

Each student was given three minutes to memorise as many words as possible from a set of 12 contained in the shape of a pyramid, then they had to read aloud passages from the daily newspaper to prevent them from rehearsing the original 12 words. After 12 minutes the students were given a blank sheet of paper and another three minutes to redraw the pyramid with the words positioned in the correct places. Mobile-phone exposure for those students with phones lasted the full 15 minutes. The participants were tested on their ability to recall words correctly. Omissions or incorrect words were called "semantic" errors and incorrectly positioned words or blanks were called "spatial" errors.

The collated results showed differences according to the gender of the subjects: Male students exposed to an active mobile phone made about 20% fewer spatial errors than the male students exposed to an inactive phone. The female students were largely unaffected by the experience.

Following this part of the experiment, the second phase invited the students to return to the same place a week later for another test but without telling them that they would be asked to recall the same words and shape. This time, all the subjects performed about the same in recall.

Further tests are planned to examine the effects of higher-powered phones than the test's standard Ericsson A2618s model, which delivers a modest 0.8 W/kg. Smythe and Costall are also interested to see if the gender effect is noticeable before the onset of puberty.

However, the results obtained so far don't simply mean that mobile-phone use is good for short-term memory. Although Smythe is fairly confident that typical mobile-phone use is harmless, he told Lightwave Europe, "The fact that mobile-phone exposure influences brain function in any measurable way could possibly mean that cumulative EMF exposure could result in damage."

What other mysterious effects could be lurking in the networks and wavelengths around us? Read on for further details of hybrid CWDM/DWDM developments, all-optical troubleshooting, new material processes to shrink components, and more.

Matthew Peach
Editor-in-Chief, Lightwave Europe

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