Perseveration

perseveration \pər-ˌse-və-ˈrā-shən\ noun: pathological repetition of a word, phrase, gesture or act despite the absence or cessation of a stimulus, often associated with brain damage or schizophrenia

Etymology: Latin perseveration-, perseveratio, from perseverare, from per- through + severus severe

We all know the word perseverance; it stems from the same root as perseveration, but it is a different kind of steadfastness, one that is looked upon as a favorable trait.