It can
be difficult to accurately distinguish between sensory craving and stereotypy.
Both symptoms play a big role in autism and both are part of the ASD¹
diagnosis, so you might think they are distinct. But they're not. They can be
easily mistaken for each other and even overlap. Does it matter that we
identify exactly what is going on? Yes. How can we create successful
interventions without pegging the problem correctly?
Look at
the descriptions and examples below and see if you can pick out inherent
problems. See if you notice the areas of overlap and blurry lines
between them, and also with them and hyperactivity (ADHD²) and obsessive
behaviors (OCD).
Stereotypy: Rapp and Lanovaz³ say, "Stereotypy
is often characterized as repetitious, invariant behavior that generates its
own reinforcing consequences (rewards)." Examples are vocalizations,
flicking fingers, slapping things, nail biting, and similar habitual
activities. The DSM describes it in terms of motor movement or use of
objects and gives these examples: "simple motor stereotypes, lining up
toys, flipping objects, echolalia, idiosyncratic phrases."
Sensory
craving: I'll venture
this definition: goal-driven behavior to satisfy
a sensory need. The DSM more broadly talks about "unusual interest
in sensory aspects of the environment ... such as ... excessive smelling or
touching of objects, visual fascination with lights or movement."
Did you
catch any problems? Stereotypy is defined in terms of motor, craving in terms
of the senses—as if the two inhabit separate worlds or separate people. But
they don’t. Let’s look at a few cases and see how the symptoms might occur in
real life.
We’ll
start with the example of the child who frequently vocalizes simple sounds or
phrases. Is it echolalia--a motor repetition? Or is it sensory
seeking: fascination with the sounds she produces, or the sensation
in her throat? Or is she doing it for some other reason such as attention
seeking? Without knowing what is driving the behavior, it's hard to classify
it. In fact, the behavior may be driven by all of these factors.
The stereotypy may co-exist with sensory seeking, and once the child learns
that her behaviors draw attention, she may use them to do so.
How do
school professionals view this behavior? It will likely be a mixed bag. First,
behaviorists⁵ and
sensory therapists will agree that the child is being rewarded by the sensation
of certain sounds. She is craving sensory stimulation; but she is
also engaging in stereotypy: behavior that generates its own reward.
While there is definite overlap of stereotypy and sensory craving here, they
will probably name it stereotypy and sensory therapists will look for any
connection to craving. Teachers, who are with children for long periods and can
see patterns in their behaviors, will be more attuned to the possibility of
attention seeking.
Now
let's explore this a little further. What about the child who has vocal
tics. Does he fall into the categories of stereotypy or craving?
No. Tics are involuntary speech and are usually the result of stress and
anxiety.
How
about a child who talks constantly? We see this in Asperger's Syndrome and
it is often pegged as repetitive behaviors, but constant talking is
also a symptom of ADHD hyperactivity. How do you distinguish between
impulsive talking and self-rewarding ("He just likes
to hear himself speak") stereotypy? For the unpracticed observer, the
signs seem subtle, but the give-away to it being a repetitive behavior is
constant talking about a single topic (such as types of
aircraft). Finally, is the non-stop talking a sensory behavior?
That's possible, but less likely.
Let's
look briefly at a few more examples: children who touch everything or
sniff things. Are these considered sensory cravings? Almost certainly, but it
may be more than that. Some children learn about their world using alternate
sensory paths: smell or touch instead of vision and hearing, and so the seeking
behaviors may be a form of learning. But which came first: the craving or the
learning pattern? It’s hard to know. And to further complicate things, the
behavior can also be tagged as stereotypy, if she smells or touches the
same things over and over in an “invariant pattern”.
Finally, let’s ask if a
behavior that looks like stereotypy is actually obsessive compulsion
(OCD). Hmm, it could be. The child who touches things in a certain prescribed
way, may have OCD. The motivation for the behavior will be fear-based: "If
I don't move in this exact sequence, something bad will happen",
rather than the reward-based behavior of stereotypy. (The topic of
differentiating OCD from stereotypy is explored in an article by Chok and Koesler
in the September, 2014 issue of Behavior Modification journal, a special issue
devoted to stereotypy, and I may blog on that at a later time.)
You can see that symptoms
can be easily confused. In my years of teaching classes on the topic
of self-regulation, I heard numerous accounts of doctors confusing
craving or stereotypy with hyperactivity or OCD and giving children
ADHD or OCD meds. It's truly important to distinguish the nuanced behavior
so that the correct intervention is given.
In my next post, I'll look
at the approaches taken by behavioral and sensory therapists to stop these
behaviors. Sometimes the interventions are surprisingly alike.
Footnotes and References
-
Autism Spectrum Disorder
- American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders. Arlington, VA: American Psychiatric Association.
- Attention-Deficit Hyperactivity Disorder
- Rapp, J. T., & Lanovaz, M. J. (2014). Introduction to the special issue: Assessment and treatment of stereotypy. Behavior Modification, 339-343.
- Rispoli, M., Camargo, S. H., Neely, L., Gerow, S., Lang, R., Goodwyn, F., & Ninci, J. (2014). Pre-session satiation as a treatment for stereotypy during group activities. Behavior Modification, 392-411.
- Chok, J. T., & Koesler, B. (2014). Distinguishing obsessive compulsive behavior from stereotypy: A preliminary investigation. Behavior Modification, 344-373.
