Perseveration
Perseveration is the continued repetition of a word, phrase, or mental operation well past the point at which it is still relevant, so that it intrudes into and prevents progress on a new task or question. A classic example is a person who, having correctly named a previous fact, gives the same answer again when asked a different, related question.
This has traditionally been treated as a sign of organic brain disturbance, distinguished from a matter of the person's will or preference: they are not choosing to repeat themselves, and the difficulty tends to worsen as the task in front of them becomes harder.
Recognition features
- A word, phrase, or idea from a previous response inappropriately reappears in the answer to a new, different question
- Tends to worsen as the difficulty of the task increases
- The person may, especially early on, notice the repetition and try, with limited success, to correct it
- Strongly associated with generalised or localised organic brain disease when present
Eliciting it at interview
- Ask a short series of related but distinct questions (for example, naming a former office-holder followed by naming the current one) and listen for the previous answer intruding into the new response
- Use simple cognitive tasks of graded difficulty, since perseveration becomes more apparent as task difficulty increases
- Note whether the person appears aware of the error and attempts self-correction, which is common in earlier or milder presentations
Distinguishing features
- Differs from verbal stereotypy, in which the same word or phrase is repeated regardless of the situation or question, rather than a specific earlier answer specifically intruding into a new, different one
- Is not a matter of volition or preference, which helps distinguish it from a habitual verbal mannerism
- Its severity tracking with task difficulty is a useful bedside clue distinguishing it from other repetitive speech patterns
Common misconceptions
- That perseveration reflects simple inattention or not listening properly to the new question; it instead reflects a specific difficulty in shifting mental operations once they are underway
- That any repeated word or phrase in speech is perseveration; the defining feature is that a specific previous answer intrudes into a new, different question, not repetition in general
Related phenomena
Verbal Stereotypy · Motor and Verbal Perseveration · Lowering of Consciousness
Practice this
Asked to name the current prime minister, a patient with known brain disease answers correctly. Asked next what day of the week it is, he repeats the prime minister's name instead. He seems to notice something is wrong and tries again, with limited success. What is this? · A patient responds to every single question in an assessment, regardless of its content, with the same fixed phrase, 'I don't know, I don't know', showing no variation in relation to what is actually being asked. Before revealing the answer: is this perseveration? · A patient repeats something during the interview. Before revealing the answer, decide what distinguishes echolalia from perseveration. · A patient, asked a question about his name, answers correctly. Asked next what year it is, he again says his own name. Is this motor perseveration? · A patient repeats the same word or phrase more than once during an assessment. Before revealing the answer, decide what distinguishes perseveration from verbal stereotypy. · A patient's speech contains repeated content that does not fit the current question. Before revealing the answer, decide what distinguishes verbal stereotypy from perseveration. · A patient repeats the same verbal content over and over. Before revealing the answer, decide what distinguishes verbigeration from perseveration. · You want to test a patient for perseveration during a cognitive assessment. Before revealing the answer, decide how you would go about it. · Explain why perseveration getting worse as task difficulty increases is a clinically useful bedside observation.
Illustration
Asked to name the town he grew up in, a 74-year-old man with a progressive memory disorder correctly answers "Preston." Asked immediately afterward what he had for breakfast, he answers "Preston," pauses, looks puzzled, and tries again: "Preston — no, that's not right, I mean..." before trailing off, clearly aware something has gone wrong but unable to retrieve the correct answer.
References
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 4, 'Disorders of Thought and Speech'.