The purpose of this study is to investigate possible effects of radio frequency electromagnetic fields on EEG activity during sleep and on Brain function during wake (EEG in the resting state condition, slow EEG potentials, auditory evoked potentials) and cognitive performance measures in test of selective attention, divided attention and working memory in healthy elderly females (60 - 80 years).

To investigate possible effects of radio frequency electromagnetic fields on EEG activity during sleep and on Brain function during wake (EEG in the resting state condition, slow EEG potentials, auditory evoked potentials) and cognitive performance measures in test of selective attention, divided attention and working memory in healthy elderly females (60 - 80 years).

Subjects will be exposed with signals from mobile communication handheld devices for 7.5 h during the night and for the whole duration of the test session during the day. Exposures will be GSM (900 MHz), TETRA (400 MHz) and sham. Each subject is exposed with each exposure three times in addition to an adaptation/screening night and day to learn the test.

The results have to be discussed in the context of possible health risks resulting from RF

Inclusion Criteria:

• healthy male subjects (age 60 - 80 years) right handedness alpha EEG as resting state EEG

Exclusion Criteria:

• acute illness severe neurological, psychiatric or internal disease CNS active medication sleep disorders drug abuse