Blocking of EEG alpha activity during visual performance in healthy adults. A quantitative study

The reactivity of the electroencephalogram was studied in a group of 54 healthy adults (23 women and 31 men, aged 23–80 years). The amplitude ratio between the situation with eyes closed and that with eyes open (EC/EO ratio) was calculated from quantitative parameters for each subject. The whole group was further divided into two subgroups according to age (younger than 60 and older 60 years). In the temporo-occipital bipolar derivations (T6-O2, T5-O1), a negative was found between alpha amplitude ratio and age in the whole group and especially in the subjects older than 60 years.