Mentalism is a performing art in which its practitioners, known as mentalists, use mental acuity, principles of stage magic, and psychological tools like hypnosis and intuition to present the illusion of extraordinary cognitive powers. This discipline often includes mind reading, telepathy, clairvoyance, divination, precognition, psychokinesis, mediumship and memory feats. Originating from spiritualist practices in the late 19th century and having roots in circus sideshows and vaudeville acts of the time, it evolved into a specialised branch of magic in the 20th Century. Mentalists have been featured on stage in magic shows and also often in their own television programs. Notable figures in this field include Derren Brown and Uri Geller. The techniques employed by mentalists are underpinned by a deep understanding of psychology and human behaviour.