Thomas Laycock FRSE FRCPE (10 August 1812 – 21 September 1876) was an English physician and neurophysiologist who was a native of Bedale near York. Among medical historians, he is best known for his influence on John Hughlings Jackson and the psychiatrist James Crichton-Browne. Laycock's interests were the nervous system and psychology; he is known as one of the founders of physiological psychology. He was the first to formulate the concept of reflex action within the brain, and is also known for his classification of mental illnesses. Life Laycock was born on 10 August 1812 in Wetherby, Yorkshire, and was the son of Wesleyan minister Rev Thomas Laycock. He attended the Wesleyan Academy on Woodhouse Grove in West Yorkshire. At the age of fifteen, Laycock trained as an apprentice surgeon-apothecary under a Mr. Spence. He went on to study at the University College in London and furthered his training in Paris in 1834 for two more years, where his instructors included Alfred Armand Velpeau (1795–1867) and Pierre Charles Alexandre Louis (1787–1872), renowned as an initiator of statistics. While in Paris, Laycock studied anatomy and physiology under Jacques Lisfranc de St. Martin and Velpeau at la Pitié. In the spring of 1837, Laycock began to learn German to further his readings beyond English and French literature. In 1839, he went to Germany and received his doctorate degree under Professor Karl Friedrich Heinrich Marx at University of Göttingen in Lower Saxony, Germany. Throughout 1839 to 1840, Laycock published many papers on hysteria and other mental illnesses. In his final paper on hysteria, Laycock wrote about the effects of hysteria on consciousness seen in comas, delirium, hallucinations, and somnambulism. This final paper introduced the revolutionary concept that stimuli to the brain could invoke actions in the subject without the subject being aware of them. This concept steered away from the notion of man as a unique spiritual human being, and saw man as more automated and animalistic. After receiving his doctorate degree in 1839, Laycock returned to York working as a physician at the York Dispensary and lecturer of medicine at York Medical School. During his time at the York Dispensary, he earned himself a reputation as a skilled physician, as well as a profound thinker, medical scientist, and prolific writer. In 1852, Laycock first encountered Hughlings Jackson, a new student; he also taught Jonathan Hutchinson whom Jackson was to meet in 1859