title: THE INFLUENCE OF AGE, HYPOPHYSECTOMY, THYROIDECTOMY, AND THYROXIN INJECTION ON SIMPLE REACTION TIME IN THE RAT.
abstract: Thyroxin injection with associated increases in metabolic rate does not significantly affect simple reaction time to an electric shock. Hypophysectomy and thyroidectomy with associated decreases in metabolic rate produce a slight decline in reaction speed. Reaction time is long in young animals, probably due to incomplete development of certain integrative and conductive systems; it remains virtually constant between puberty and relatively advanced age when it increases rapidly, probably due to physicochemical changes in the composition of the conducting nervous system.
authors.affiliation: Departments of Dairy Husbandry and Psychology, University of Missouri, Columbia.
authors.forename: E B
authors.initials: EB
authors.lastname: Brody