Hugo Liepmann

Hugo Karl Liepmann (April 9, 1863 - May 6, 1925) was a German neurologist and psychiatrist who was a native of Berlin. In the 1890s he was an assistant to Carl Wernicke in Breslau, and later became a professor of neurology at the University of Berlin.

Liepmann is remembered for his pioneer work concerning cerebral localization of psychological function. From anatomical studies, he postulated that planned or commanded actions were controlled in the parietal lobe of the brain's dominant hemisphere, and not in the frontal lobe. Beginning in 1900, he began extensive work with a disorder he called apraxia. Apraxia is the inability to act or move different parts of the body in a purposeful manner, even though the physical capability of movement is normal. Liepmann believed that damage in the parietal lobe prevented activation of learned sequences of actions that are necessary to produce desired results on command. As a result of his studies, he divided apraxia into three types:
 * ideational: object blindness, where the patient is incapable of making appropriate use of familiar objects upon command.
 * ideomotor: the inability to follow verbal commands or mimic an action, such as saluting or waving goodbye.
 * kinetic: clumsiness in performing a precision act that is not due to paralysis, muscle weakness, or sensory loss.