The invention is directed to the use of Ginkgo complexed with phosphatidylserine for the manufacture of a medicament or a dietary supplement for the enhancement of cognitive function and mental fatigue, i.e. to improve the factors related therewith such as to improve the speed of memory and memory quality, to increase accuracy and attention in activities in normal, healthy subjects, to prevent deterioration of the speed and quality of memory in people with decreased cognitive functions and to counteract cognitive fatigue, having also an influence on the mood, particularly in healthy children, young adults, middle-aged and/or old people. It is further provided the use of the Ginkgo phosphatidylserine complex for the treatment and prevention of a disease related with a decrease of the cognitive function and mental fatigue such as Dementia, e.g. Alzheimer's Disease.