The inability to repeat others’ speech is a common impairment among patients with aphasia

aphasia. Naturally, this impairment varies considerably based on aphasia type and severity. Although impaired repetition is found in several of the different aphasia types, it is the primary impairment in conduction aphasia. In 1874 Wernicke predicted that severing the connection between the speech production and comprehension modules included in the Wernicke-Lichtheim (Lichtheim, 1885; Wernicke, 1874) model would result in a disorder of repetition where speech fluency and comprehension remained intact. Although Wernicke had never seen such a patient at the time of his prediction, a patient with this condition was later described by Lichtheim (1885). Today, the definition of conduction aphasia is largely unchanged: Impaired repetition with relatively spared speech fluency and auditory comprehension. Conduction aphasia has been classically viewed as a result of acquired brain damage involving the left arcuate fasciculus where, true to the Wernicke-Lichtheim model, the connection between the posterior comprehension areas in the temporal lobe are disconnected from the anterior speech production region in the posterior-inferior frontal lobe; hence, conduction aphasia is commonly referred to as a disconnection syndrome.