Functional food products should provide scientifically proven beneficial effects in healthy subjects. The highly sensitive method of EEG recording from healthy human volunteers was used in a randomized, placebo controlled crossover study to investigate the effects of a change in physiological parameters after ingestion of a total of 750 ml of a softdrink containing 0.232 g of ginseng and 2 g of ginkgo extract, both produced by water extraction. Application of a random, placebo controlled crossover design was done with 10 healthy male volunteers. EEG recordings were performed 1, 2, 3 and 4 h under the conditions of 10 min eyes open, 5 min eyes closed and 5 min reading short stories. Auditory P300 potentials were recorded every hour in addition to the EEG recordings. Source density analysis of the data revealed an attenuation of circadian induced electrical delta power decreases under the condition of eyes open and closed recording from centro-parieto-occipital electrode positions. During a reading test even absolute increases of delta power were observed at these electrode sites. These changes were statistically significant at p < 2% for the second hour (eyes open and reading) and are interpreted to indicate a higher degree of emotional well-being. Decreases in latency (from 333.9 to 321.3 ms) as well as increases of amplitude (from 2.07 to 3.95 microV) of the auditory P300 potential at the electrode position Pz point to a possible improvement of attention, however, the difference did not reach statistical significance.