The neurotransmitter histamine is gaining attention by the scientific community and pharmaceutical industry, as it has been shown to be involved in disorders like Parkinson's disease, Alzheimer's disease, Attention Deficit Hyperactivity Disorder and schizophrenia. Increasing histaminergic activity in rodents has shown to increase cognitive functioning, which may therefore possibly serve as a new treatment. In order to understand the role of histamine in human cognition and determine whether new treatments may be suitable, this thesis describes experiments in which the effects of lowered histamine functioning on performance tests and Event Related Potentials are measured.