and Stereotyped Behavior in Autism;
Review of Behavior Analytic Perspectives
Connecticut State University
One of the distinguishing
features of many children with autism is their frequent engagement in
repetitive, apparently non-functional behaviors.
These have been historically been referred to as stereotypic behaviors.
Currently behavior analysts and others recognize other inappropriate
behaviors directed at producing self-sensory stimulation
and have broadened the area of concern to include all of these
“self-stimulatory” behaviors, some of which are more subtle to detect than
traditionally defined stereotopy. This
class of behaviors is problematic in all of its forms because of the obstacles
to learning they present and their socially stigmatizing nature.
Viewing these inappropriate behaviors as variations of normal functioning
is effective in understanding possible functionality of these behaviors.
This in turn offers important insight into the treatment of such behavior
excesses. Recent research on the
motivational components of antecedent conditions can also prove an important
tool in autism treatment.
with autism engage in apparently non-purposeful, repetitive sequences of fixed
behaviors including movement patterns (hand-flapping,
body-rocking, spinning or flipping of objects) and repetitive vocal sequences
(echolalia). The presence of
stereotypical movements has been a key feature of the syndrome of autism since
Kanner originally described it in the 1940’s.
These stereotyped behaviors are characterized mostly by their cyclical
and rhythmic nature (Berkson, 1983) and have been documented and studied in
other human populations such as nursing home patients
(Cohen-Mansfield, 1991) and drug addicts (Lewis, Baumeister and Mailman,
1987), and extensively in animal research.
Along with stereotypies, behaviorists generally include other
non-rhythmic behaviors, such as atypical body postures and staring into lights,
within a broader category of human behaviors referred to as self-stimulatory
behaviors. These behaviors
are produced and received by the performer, and are not always pathological in
nature. Some examples of normal
self-stimulatory behaviors are dribbling a basketball and playing solitaire
(Newsom & Lovaas, 1987).
However, because of their often excessive and behaviorally unusual nature
in children with autism, self-stimulatory behaviors can be socially
stigmatizing, thereby precluding significant inclusion in natural social,
occupational and educational environments.
These behaviors pose significant obstacles to learning and left untreated
they can easily become the dominant behavior in later years of life.
treatment of problem behaviors in people with developmental disabilities has
become an area of prolific study, with numerous articles addressing assessment
and intervention (Cuvo, 1997).
This paper will attempt to provide the reader with an overview of
behavior research on the effect of self-stimulatory behaviors on learning and
the acquisition and maintenance of such behaviors among children with autism
from a functional perspective of their consequences and in terms of their
research in the area of self-stimulation and learning in children with autism
included a study by Lovaas, Litrownik,
and Mann, 1971) which documented significant increase in response latencies when
children were engaged in self-stimulatory behavior.
A few years earlier, in 1968, Risley had reported an increase in certain
appropriate behaviors when self-stimulatory behaviors were punished (Koegel
& Covert, 1972). These studies
suggested to other researchers the possibility that skill acquisition could be
enhanced through a reduction of self-stimulatory behaviors.
In the early 1970’s Koegel and Covert conducted experiments that
attempted to define a functional analysis of the relationship of discrimination
learning and self-stimulatory behavior in children with severe autism.
They examined (1) whether the children they studied failed to acquire
discrimination learning tasks when engaged in self-stimulatory behaviors, (2)
whether the suppression of such behaviors resulted in an increase in learning of
the desired behaviors and (3) whether there was a spontaneous reduction of
self-stimulation (without external
suppression) during skill acquisition. In
one experiment that they conducted, subjects were trained to respond by pressing
a bar for a reinforcer when a light and tone were presented (SD)
and to refrain from responding during the negative stimulus (SD)
interval (absence of light and tone). Training
was first provided without suppression of self-stimulatory behavior for a
significant number of trials, and then during a period in which self-stimulatory
behaviors were suppressed (by the experimenter sharply saying “No!” and when
necessary, delivering a “brisk” slap on the hands to interrupt the
and Covert documented that skill acquisition was not achieved during the “no
suppression” period and that the target discrimination task was learned during
the “suppression” phase. The
data revealed a clear, almost perfectly inverse relationship in the rate of
correct responses to the rate of self-stimulation.
In a related
experiment, Koegel and Covert recorded baseline rates of self-stimulatory
behavior during a pre-training period.
Discrimination training was then initiated
(without suppression) and was followed by another “free” period
without training. The results
showed a high rate of self-stimulatory behaviors in phase 1 (absence of
discrimination training) with children engaging in these inappropriate behaviors
for a majority of time in the pre-training period.
This was followed by marked decrease in self-stimulation during training
(again displaying an inverse relationship between the variables, as correct
responses increased, stereotypy decreased), with a return to somewhat higher
levels of self-stimulation in the period immediately following discrimination
training (but significantly lower levels than in the pre-trial period).
Koegel and Covert concluded that self-stimulatory behavior is
incompatible with successful learning. Some
children can spontaneously reduce self-stimulatory behavior without external
suppression during discrimination training and we can expect acquisition of the
skill in these cases. For
others, external suppression of self-stimulatory behaviors is a prerequisite for
learning new skills (Koegel & Covert, 1972).
Later work by Koegel found that suppression of self-stimulatory behavior
produced an increase in appropriate play without the use of external
reinforcers, but that regression to base stereotypy rate returned when
suppression was discontinued.
Functions of Self-Stimulating Behavior
feature of stereotypic behavior is that it appears to be non-adaptive and
purposeless, behavior analytic research suggests that stereotypic and other
self-stimulatory activities serve to provide and regulate sensory input from the
environment. It has been proposed
that these behaviors are operant responses that serve as an effective block
during times of excessive or aversive environmental stimulation and can provide
sensory input during periods of under-stimulation. Lovaas, Newsom and Hickman proposed a theory of “perceptual
reinforcement” in which they relate self-stimulatory behavior to the innate
need for stimulation among all organisms and that the excesses in these
behaviors among children with autism is a consequence of the absence of
appropriate alternative behaviors for accessing such stimulation.
et al., 1987).
position is that everyone, handicapped or not, both requires and can be rewarded
by certain amounts and kinds of stimulation, as indicated in the literature on
sensory deprivation and sensory/perceptual reinforcement.
The major difference between normal and handicapped persons lies in how
the stimulation is obtained:
obtain their stimulation primarily through normal verbal, social, work and
recreation/leisure behaviors, whereas retarded and autistic persons obtain
theirs through simpler behaviors, many of which are repetitive and stereotyped
(Newsom & Lovaas, 1987).
These operant responses are
maintained by the automatically reinforcing perceptual consequences (Newsom
& Lovaas, 1987). The
consequences of self-stimulatory behaviors are so highly reinforcing that this
type of behavior is often chosen over other primary reinforcers
(Lovaas et al., 1971).
It has been
found that the removal of a specific sensory consequence causes a reduction of
self-stimulation associated with that particular consequence (Rincover, Cook,
Peoples and Packard, 1979). Rincover
and colleagues studied the role of sensory reinforcement in maintaining
self-stimulation, and whether this preference for specific sensory stimulation
could be used to facilitate appropriate toy play.
Four children with autism were observed while engaging in stereotypic
behavior and the behaviors were categorized by various sensory consequences they
produced. Self-stimulatory behaviors (and the specific sensory consequences
produced) were defined individually for each subject.
For example they observed that one child, Reggie, continually chose to
spin a plate on a hard surface, and appeared to lean in to listen to the sound
of the plate as it whirled around. It
was determined that the sensory pay-off for this behavior was auditory.
In the first part of the study, sensory extinction procedures were
designed for each child, corresponding to the type of sensory consequences
identified with their behaviors. For
Reggie, carpeting was installed on the flat surfaced he used for plate spinning.
The carpeting did not interfere with the spinning, but no sound was
audible from the spinning plate during this part of the experiment.
Similar sensory extinction procedures were designed and implemented for
each child, based on their specific stereotypy.
Extinction of the self-stimulatory behavior occurred in all the children
when the sensory reinforcer was removed.
In phase 2, Rincover et al. found that the defined sensory reinforcers
could be used to train appropriate play with toys that imitated the preferred
sensory reinforcer (e.g. a music box and an autoharp for Reggie to provide
auditory feedback) and that these behavior changes remained intact for several
months without external suppression of self-stimulation or the use of external
have identified the function of stereotypy as a method of social interaction,
i.e. to influence the behavior of others in order to either access or escape
stimulation or instructional requests. Self-stimulatory
behaviors can be maintained in the individual with autism through negative
reinforcement by reducing or escaping from unwanted social interactions.
These studies suggest that stereotypy and other self-stimulatory
behaviors serve multiple functions for the child with autism (Kennedy, Meyer,
Knowles, and Shulka, 2000).
research on the multiple functions of stereotypic responses includes two studies
by Kennedy and colleagues (Kennedy et al., 2000).
In one, a multi-element design was utilized to determine the rate of
stereotypic responding under four separate conditions (attention, demand, no
attention and recreation). During
the attention condition, the experimenter and the subject engaged in separate
activities, with the researcher providing 5 seconds of attention to the student
when stereotypy occurred. During
the demand condition, the child was given an instructional request every 15
seconds, with praise for correct responses and full physical prompts for
non-compliance. Task demands were
suspended for 30 seconds immediately following stereotypic activity (to assess
the impact of negative reinforcement in the form of escape from environmental
demands). During the no-attention
condition the child received no social interaction or assigned activities,
assessing the rate of stereotypic behaviors in the absence of environmental
stimulation (and presumably for sensory reinforcement).
During the recreational condition, the child was given various preferred
activities and praised every 15 seconds in the absence of stereotypy (control
condition to minimize stereotypic behavior).
The results confirmed that stereotypic responses served multiple
functions: to access positive (attention) and negative (escape) reinforcer
functions within a social
context, and to provide sensory stimulation (consistent with perceptual
In a second
experiment, multiple reinforcer functions of stereotypy that were identified in
the preceding experiment were paired with functional communication training
(FCT) to teach separate alternate behaviors for each function that was
previously determined to influence the occurrence of stereotypic responses
(social attention, escape from instructional demand and sensory stimulation).
Hand raising was taught to acquire adult attention, signing “break”
was taught to escape instructional demands, and signing “more” was taught to
access preferred sensory stimuli. Kennedy
et al. documented significant decreases in stereotypic behaviors following the
FCT training. Their
research supports past studies on the functional components of self-stimulatory
behaviors (perceptual reinforcers
and social interactions). In
addition, their work offers important implications for the design of treatment
programs for self-stimulatory behaviors, with considerable emphasis on the need
to provide alternative behaviors in the treatment/education considerations for
children with autism.
Influence of Motivational Antecedent Events on Problem Behaviors
relationship of EOs to problem behavior is a relatively new topic in behavior
analysis. Several common EOs
have been identified in the motivation of problem behavior, including attention
deprivation, deprivation of tangible items, deprivation of stimulation, etc.
It has therefore been suggested that application of this concept to
the treatment of problem behaviors among people with developmental disabilities
could benefit by focusing on modifying the environmental challenges that these
people experience, rather than on the manipulation of contingencies (McGill,
study of motivational aspects of antecedent conditions is an area worthy of
further investigation. It offers
potential to increase efficacy of treatment programs for self-stimulatory
behaviors, especially when combined with current understanding of the functional
components of these behaviors and the consequences of neglect in this area of
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