EEG profile of three different extractions of Ginkgo biloba

Two experiment were conducted to assess the electroencephalographic effects of (1) three different dosages of a total extract of Ginkgo biloba (EGb 761, Tebonin) and (2) three different extractions of G. biloba (Tebonin and two fractions from it). The medicament was tested against placebo using a double-blind cross-over design in 12 normal healthy males for each experiment. Medication was administered for 3 days preceding the recording sessions. 25 parameters were computed from the EEG spectra. Medication-related effects were obtained for most of the power measures, whereas dominant frequencies of the respective frequency band remained largely unchanged. The differences between the EEG effects of the two studies are critically discussed.