The early history of cognitive neuropsychology begins with humans’ first acknowledgement of the mind/brain. Beliefs in the importance of the mind/brain/head emerge as early as 4000BC with the Sumerians. Records of Sumerian intake of the poppy plant (which contains opium) include descriptions of the mind-altering affects upon ingestion. This suggests a reference to the brain. Another clue pointing towards acknowledgement of the brain is the discovery of skulls with holes drilled into them in 2000BC. Discovery of these skulls points to cultural acknowledgement of the brain as important to life. The motivation behind these drillings could vary from spiritual to medical.