According to Allison,[1] the term “perseveration” was used first by Neisser in 1894 as a label for the repetitive
production of the same response to different commands. No doubt the phenomenon called
“perseveration” was observed by clinicians much earlier than that date because it
is a very frequently occurring behavior associated with neurological disorders of
the brain. In fact, perseveration is such a pervasive and vexing problem that it has
received much clinical and research attention for more than 100 years. Interestingly,
however, despite this attention, the mechanisms responsible for perseveration have
remained elusive.[2] What is more certain, is that perseveration is not a unitary phenomenon but rather
manifests itself in various forms and across all modalities of response output. Speech
and language pathologists and other clinicians working with individuals who have experienced
such neurological events as strokes and traumatic brain injury and such progressive
neurological disorders as Parkinson's disease and forms of dementia are well aware
of the common occurrence of perseveration in these populations. Furthermore, they
are familiar with the ways perseveration can interfere with assessment and treatment
procedures and, more importantly, functional activities.
Perseveration is, perhaps, one of the most interesting behaviors observed by clinicians
and studied by investigators from various disciplines. In my own clinical practice
I am continually amazed at the ways perseveration can manifest itself. For example,
I recently saw an individual who had experienced a large left hemisphere stroke and
displayed what might be labeled “pervasive” perseveration. He displayed the three
primary forms of perseveration (stuck-in-set, continuous, and recurrent; for definitions
see McNamara and Albert,[3] in this issue), and these forms occurred on various tasks and modalities. He often
pointed to the same (incorrect) items on an auditory comprehension test, whereas on
writing tasks he repeated letters and words. In drawing, elements of one drawing would
be carried over to other drawings. His speech output was highly perseverative with
inappropriate recurrence of both words and phonemes. Not surprisingly, the neuropsychologist
evaluating him found that the same problems contaminated his performance and resultant
test scores. In such cases, it appears that perseveration is blocking what may be
at least partially preserved underlying skills. Those of us who are therapists cannot
help but think about and pursue ways to “unblock” performance potential by helping
such patients control and even eliminate there perseverative behaviors. To begin to
accomplish such a feat, however, we must understand what perseveration is all about,
what causes it, and what factors can increase or decrease its occurrence. In other
words, if we are to develop successful methods for treating perseveration, we must
get a better “handle” on underlying mechanisms.
As a “seasoned” clinician and therapist, I have a great interest in the puzzling problem
of perseveration. So, when Hugh Buckingham and Sarah Christman offered to serve as
guest editors for an issue of Seminars in Speech and Language devoted solely to perseveration, I was delighted. I was familiar with the excellent
work and writing of both of these individuals and have read all of Dr. Buckingham's
publications on perseveration. I knew that they would know the best people to write
articles for this issue and that they would make my job as an editor-in-chief relatively
easy in many ways. That proved to be the case. Not only did Buckingham and Christman
make sure that I received a well-edited group of articles in a timely manner, but
also they provided me with an opportunity to learn a great deal more about perseveration
through reading these “cutting edge” articles. I think that all readers will find
them as informative and intellectually provocative as I did.
In closing, I must point out that this is the last issue of Seminars in Speech and Language for which I will serve as Co-Editor in Chief. I have had the pleasure of doing this
job for 5 years, during which time 10 issues devoted to adult topics were published.
It has been a pleasure working with Nan Bernstein Ratner and the people at Thieme
Medical Publishers, especially the very competent and pleasant Production Editor,
Xenia Golovchenko, whom I have never met but feel I know. Thank you Xenia, and all
the Guest Editors and authors who helped bring the 10 issues to fruition. It has been
a multifaceted learning experience for me and I look forward to reading future “Adult
Focus” issues of SSL that will be in the very capable hands of Audrey Holland starting
with the next issue.
