Some current themes in functional analysis research

Pergamon

Researchin DevelopmentalDisabilities,Vol.17, No. 3, pp. 229-249, 1996 Copyright© 1996ElsevierScienceLtd Printedin the USA.Allrightsreserved 0891-422.2/96$15.00+ .00

PII S0891-4222(96)00006-6

Some Current Themes in Functional Analysis Research Timothy R. Vollmer Louisiana State University

Richard G. Smith University of North Texas

The purpose of this article is to review and discuss some current themes in functional analysis research. The paper is divided into two general sections; one section discusses clinical application o f functional analysis and a second section discusses functional analysis as a research method. In the first section, current issues related to treatment logic and development are reviewed. Also, clinical limitations of functional analysis are described, including treatment and assessment implementation issues (such as time and resource constraints), in the second section, three areas o f research are reviewed with suggestions f o r further research: the analysis o f diverse response topographies, the analysis of basic behavioral processes, and the evaluation of methodological refinements.

Functional analysis has emerged as a most potent and effective behavioral assessment methodology for disorders associated with developmental disabilities. Functional analysis is generally described as a preintervention assessment designed to identify environmental factors responsible for occasioning and/or maintaining behavior. M u c h has been written about the logic of functional analysis (e.g., Mace, Lalli, & Pinter-Lalli, 1991), and the success o f f u n c t i o n a l a n a l y s i s as a f o r m o f a s s e s s m e n t (e.g., N e e f & I w a t a , 1994). Requests for reprints should be sent to Timothy R. Vollmer,Department of Psychology, Louisiana State University, Baton Rouge, LA 70803. 229

230

T. R. Vollmer and R. G. Smith

However, most discussions of functional analysis have focused on the methods utility in prescribing effective interventions. Although recent discussions of functional analysis have also identified several weaknesses of functional analysis methods (Sturmey, 1995), those limitations are perhaps drawn from the assumption that the goals of functional analysis are purely clinical. Functional analysis as a form of more basic research has received relatively little attention in the literature. The purpose of this paper is to discuss two general themes in current functional analysis research: (a) functional analysis as an assessment method for treatment prescription (clinical application) and (b) functional analysis as a research method. Recent developments and limitations in each area will be presented as will some possible directions for future research. To begin, we will draw a distinction in terms. Recently, the term functional assessment has been used to describe a range of procedures designed to identify maintaining variables for severe behavior problems. Such procedures include interviews (O'Neill, Homer, Albin, Storey, & Sprague, 1990), descriptive observations (Mace & Lalli, 1991), questionnaires, and rating scales (Durand & Crimmins, 1988). Functional analysis, on the other hand, refers to more specific procedures in which environmental variables are directly manipulated (Homer, 1994). In terms of treatment prescription, the goal of functional analysis is to experimentally identify operant reinforcement contingencies maintaining problem behavior in order to more directly prescribe effective behavioral interventions (Iwata, Slifer, Bauman, & Richman, 1982/1994). Thus, functional analysis can be considered a component of a more comprehensive functional assessment (Sturmey, 1995). However, conceptualizing functional analysis solely as a subcategory of functional assessment is not entirely accurate. In fact, a thesis of this paper is that the utility of functional analysis extends beyond clinical assessment goals. Skinner (1953) proposed that significant human behavior might best be addressed using function-analytic approaches, arguing that knowledge about the reinforcement contingencies associated with such behavior would permit the development of better methods for establishing, increasing, generalizing, limiting, or decreasing it. The initial adaptation of functional analysis logic and methods for assessing behavior disorders was associated with research on the evaluation and treatment of self-injurious behavior (SIB). Carr's (1977) seminal review of the SIB literature brought together findings from diverse fields to support several operant hypotheses related to the development and maintenance of self-injury. Specifically, Carr's review suggested that self-injury can be reinforced by contingent social positive reinforcement (attention or tangible items), social negative reinforcement (e.g., escape from aversive environmental stimulation, such as instructional demands), and/or contingent sensory or automatic reinforcement (e.g., self-stimulation). Carr's hypotheses were subsequently tested in an analog environment by Iwata et al. (1982/1994).

Functional Analysis

231

In the Iwata et al. (1982/1994) study, participants who engaged in severe self-injury were observed during four distinct experimental conditions that were presented in a multielement single subject experimental design. Fifteenmin sessions were alternated randomly until clear patterns of differential responding were observed. The experimental conditions were: Reprimand, Academic Demand, Alone, and Unstructured Play. In the reprimand condition, participants were allowed to play with toys but were otherwise ignored unless SIB occurred. When SIB occurred, an experimenter reprimanded the participant and provided other response-contingent attention. The reprimand condition was a test for sensitivity to adult attention as a positive reinforcer for SIB. In demand, participants were presented with requests to complete academic tasks, but were allowed brief (30 s) escape periods (timeout) contingent on SIB. The demand condition was a test for sensitivity to escape from instruction as a reinforcer for SIB. In alone, the participants were observed with no toys and no social interaction. Results showed the alone condition was a test to determine whether SIB persisted in the absence of social consequences. The play condition served as a control, during which participants received noncontingent attention and access to leisure and recreational materials and received no instructional demands. The behavioral function of SIB was idiosyncratic across individuals. For example, some participants engaged in high rates of SIB only during the reprimand condition (suggesting a positive reinforcement function). Others engaged in high rates of SIB only during the demand condition (suggesting a negative reinforcement function). Finally, some subjects showed high levels of SIB that persisted in the absence of social contingencies, suggesting that their SIB was not maintained by social consequences. More recently, functional analysis methods have been used to identify reinforcement contingencies for a wide variety of behavior problems, including aggression (O'Reilly, 1995), tantrums (Derby et al., 1992), pica (Mace & Knight, 1986), and stereotypy (Mace, Browder, & Lyn, 1987), among others. Further, functional analysis methods are now being extended to socially relevant behavior disorders unrelated to developmental disabilities, such as attention deficit/hyperactivity disorder (Northup et al., 1995). The development of functional analysis methodologies can be viewed as significant for two general reasons. First, identification of reinforcement contingencies can permit researchers and practitioners to reverse or eliminate maintaining variables that inadvertently support problem behavior (i.e., clinical application). Second, functional analysis methods can serve as a form of pure applied science, directed more toward the discovery of basic behavioral mechanisms underlying significant behaviors than toward the development of techniques for addressing those behaviors. Below, we will discuss emerging themes and contributions of functional analysis as clinical assessment and as operant research in the field of developmental disabilities.

232

T. R. Vollmer and R. G. Smith

CLINICAL APPLICATION Treatment Logic

A clinical tenet of functional analysis is that behavior disorders may not be evaluated solely on the basis of response topography. For example, three people may exhibit almost identical forms of hand-biting. However, the behavior may serve as an escape function for one person, may produce caregiver attention for a second person, and may be unrelated to the social environment for a third person. A second clinical tenet of functional analysis is that behavior disorders are best classified according to similar functions. For example, treatment for aggression maintained by escape (negative reinforcement) should be more similar to a treatment for SIB maintained by escape than to a treatment for aggression maintained by attention (positive reinforcement). When interventions are selected on the basis of a prior functional analysis, the goal is to match the intervention to the results of the assessment. That is, if environmental conditions or events are shown to be correlated with the occurrence (or nonoccurrence) of target behaviors, then those environmental conditions can be addressed directly during intervention. Most importantly, the development of interventions is dependent on the function of the problem behavior - - as identified during assessment. Once a behavioral function is identified, the most direct strategy for intervention is to withhold the relevant reinforcers following inappropriate behavior (e.g., withholding attention after SIB), and to present them contingent on some appropriate behavior. For example, one type of intervention derived from a functional analysis is functional communication training (FCT; Carr & Durand, 1985). If inappropriate behavior is shown to increase as a result of contingent reprimands during a functional analysis (i.e., positive reinforcement), the intervention may involve ignoring inappropriate behavior and reinforcing a more appropriate attention-seeking response (e.g., sign language, vocalizations, etc.). However, if inappropriate behavior is maintained by escape from academic tasks, the intervention might involve continuation of academic tasks when inappropriate behavior occurs and providing brief escape periods following appropriate requests or after work completion. Extinction may be a critical component of interventions based on functional analyses. Thus, the contingent relationship between a response and its consequence should be disrupted in some way. For example, Mazaleski, Iwata, Vollmer, Zarcone, and Smith (1993) showed that differential positive reinforcement schedules were ineffective when an attention contingency remained intact. When SIB was ignored, differential reinforcement (receiving attention for the nonoccurrence of SIB) resulted in rapid reductions in SIB. Similarly, Wacker et al. (1990) showed that FCT was less effective if the procedure did not ensure that reinforcement for aberrant behavior was eliminated. Thus, functional analyses are important preintervention assessment methods not only

FunctionalAnalysis

233

because alternative behavior can be reinforced, but because the assessment outcome prescribes an extinction component: if the reinforcer can be identified, it can be withheld. The identification of reinforcers maintaining aberrant behavior is an important contribution of functional analysis research as it relates to clinical application because it improves the clinician's ability to develop effective behavioral intervention. Figure 1 portrays differential reinforcement as a choice paradigm. The upper panel shows a choice created by differential reinforcement when the reinforcer for appropriate behavior is unrelated to that reinforcer maintaining aberrant behavior. Such an arrangement may be likely to occur if the maintaining contingency for aberrant behavior has not been identified through functional assessment. The success of differential reinforcement in this arrangement depends entirely on the ability of the reinforcer for appropriate behavior to compete with the (unknown) reinforcer for aberrant behavior. The lower panel DIFFERENTIALREINFORCEMENTWITHOUTA FUNCTIONALANALYSIS ABERRANTBEHAVIOR

C

O-QCE

)

~ UNKNOWNREINFORCER

I RESULT:COMPETINGSCHEDULESOFREINFORCEMENTI

APPROPRIATEALTERNATIVE

~ PROGRAMMEDREINFORCER

DIFFERENTIALREINFORCEMENTBASEDONA FUNCTIONALANALYSIS ABERRANTBEHAVIOR

C

CHOICE

)

~ NOREINFOF~ER

] RESULT:LrI3"LEORNOCOMPETITION

" ~

APPROPRIATEALTERNATIVE

I

~ FUNCTIONALREINFORCER

FIGURE 1. Differential reinforcement as choice behavior. The upper panel portrays a choice created when the reinforcer for aberrant behavior has not been Identified, and, therefore, the reinforcer for appropriate behavior is different from the (unidentified) reinforcers for aberrant behavior. The lower panel portrays a choice when the reinforcer for aberrant behavior has been identified and can be withheld.

234

T. R. Vollmer and R. G. Smith

shows a choice created by differential reinforcement when the reinforcer for aberrant behavior has been identified (i.e., via a functional analysis). The success of differential reinforcement in the case of the lower panel depends only on the degree to which the procedure can be conducted with integrity; because, assuming perfect procedural integrity, the client is faced with a simple and highly discriminable choice: engage in aberrant behavior and receive no reinforcement or engage in appropriate behavior and receive access to the reinforcers previously contingent on inappropriate behavior. Although extinction and differential reinforcement can be accomplished by manipulating the availability of a reinforcer, recent research has shown that response-reinforcer relations also can be disrupted by presenting reinforcers noncontingently. For example, Vollmer, Iwata, Zarcone, Smith, and Mazaleski (1993a) identified (via functional analysis) three women with attention-maintained SIB. During one treatment condition, response-independent attention was presented on a progressively increasing fixed-time schedule. The fixedtime schedule began as continuous attention, but was faded to one delivery of attention (for 10 s) per 5 min time block. The logic of the noncontingent reinforcement (NCR) procedure was twofold: (a) if SIB was maintained by positive reinforcement in the form of attention, the motivation to engage in SIB might be reduced by presenting attention freely and frequently, and (b) the contingent relationship between SIB and attention would be eliminated. Results and comparisons to differential reinforcement for all three participants showed that NCR reduced SIB as well as or better than differential reinforcement procedures. The efficacy of NCR has been replicated in studies showing that the progressively increasing fixed-time schedule is an important feature (Hagopian, Fisher, & Legacy, 1994) and also in studies showing that noncontingent escape can be effective in decreasing behavior maintained by negative reinforcement (Vollmer, Marcus, & Ringdahl, 1995). From a practical standpoint, NCR schedules are appealing because the care provider does not necessarily need to monitor each occurrence of a target behavior (due to the response-independent nature of reinforcer delivery). Also, NCR schedules are less likely to yield extinction bursts characteristic of some differential reinforcement procedures, presumably because the density of reinforcement is constant in NCR schedules, but will be decreased if target behaviors occur in differential reinforcement schedules (Vollmer et al., 1993a). Just as with differential reinforcement, NCR schedules are more likely to be effective when based on a functional analysis of behavior. Noncontingent access to reinforcers, when maintaining factors for aberrant behavior are unknown, does not disrupt the contingent relationship between aberrant behavior and its consequences. Suppose, for example, that a child exhibits severe tantrums that are inadvertently reinforced by food delivery (e.g., parents deliver food to calm him down). As treatment, the parents begin to provide noncontingent attention but continue to deliver food contingent upon tantrums. Such a procedure is unlikely to be effective because the motivational

Functional Analysis

235

operation (food deprivation) and reinforcement contingency (food delivery following tantrums) are intact. On the other hand, NCR with reinforcers that are known to maintain aberrant behavior will disrupt the contingent relationship because reinforcer delivery is independent of the client's behavior. In the above example, a noncontingent schedule of snacks should alter the motivation to engage in tantrums (because food is presented freely and frequently) and would also disrupt the response-reinforcer relationship (because tantrums no longer produce food).

Limitations of Clinical Application The logic of using a functional analysis to prescribe treatment is rather direct: reinforcers that previously maintained aberrant behavior can be withheld contingent on aberrant behavior and presented either according to differential or noncontingent reinforcement schedules. Such a reversal of maintaining contingencies describes the primary role of a functional analysis from a clinical perspective. Despite the appeal of treatment logic derived from a functional analysis, several limitations may hinder the clinical application of functional analysis. In this section, we will discuss some limitations of functional analysis as it relates to clinical practice. These limitations include (a) functional analysis treatment prescriptions that are difficult to implement in practice, (b) functional analysis results that point to uncontrollable (automatic) sources of reinforcement, and (c) functional analysis procedures that are time consuming and seemingly impractical. We will also discuss potential solutions and areas of clinical research related to these limitations.

Difficulties in treatment implementation. It is clear that some interventions derived from a functional analysis can be difficult to conduct with procedural integrity. One such limitation is that the reinforcer maintaining problem behavior may be socially inappropriate or may be requested at inopportune times (even when requested appropriately). In other words, the difficulty can be as much with the reinforcer as with the client's behavior. A client who has been taught an alternative escape response or an alternative attention-seeking response may excessively engage in the alternative response. Continuous or frequent engagement in the alternative may be problematic if it occurs in inappropriate contexts, such as during instructional periods. Marcus and Vollmer (1995), for example, reported a case in which a participant continuously escaped instructional tasks by engaging in an alternative escape response (vocalization). Such an outcome of FCT is insufficient from a clinical standpoint because it may be impossible to conduct training or other habilitative routines if requests are always reinforced with escape. Similarly, a parent or teacher may be unable to provide attention when it is continuously requested (e.g., " . . . now he asks for attention all of the time, and I cannot attend to the other students; if I do not attend he begins to tantrum again."). Other problems

236

T. R. VoUmerand R. G. Smith

with differential reinforcement may arise when a client requests access to reinforcers that are unavailable (such as when food is requested while riding in a car) or at times when reinforcers should not be delivered (such as when food is requested before dinner). To address the problems related to excessive requesting, some preliminary work has evaluated the use of escalating fixed-interval reinforcement schedules in combination with FCT (Vollmer, Northup, Ringdahl, LeBlanc, & Chauvin, 1996). For example, one child engaged in severe tantrums that were reinforced by access to food. After being taught a sign for "eat," he was required to wait for progressively longer intervals before requests were reinforced. In principle, the intervals could be extended to socially relevant time periods, such as waiting an hour until dinner. Some other possible solutions to frequent or inappropriate requests include gradually increasing the time interval before an alternative request is reinforced (e.g., Day, Homer, & O Neill, 1994), or placing an escape contingency on work completion rather than on communication only (e.g., Marcus & VoUmer, 1995). Clearly, more research is needed to address problems that can arise when a client is taught a new and effective means of communicating that cannot or should not always be reinforced. Extinction-based procedures also can be difficult to implement for a variety of reasons. And, as discussed previously, if the contingency between aberrant behavior and its reinforcer is not disrupted, treatment success is compromised (Mazaleski et al., 1993; Wacker et al., 1990). One reason extinction may be difficult to implement is that it may produce a number of side effects, including extinction bursts (Zarcone, et al., 1993), response variation resulting in new forms of aberrant behavior (Lennox, Miltenberger, & Donnelly, 1987), and emotional behavior (Cowdery, Iwata, & Pace, 1990). Further, if the prescribed treatment involves escape extinction, the client is, by definition, required to stay on task. Staying on task often requires physical guidance (Iwata, Pace, Kalsher, Cowdery, & Cataldo, 1990), which can be extremely difficult or even dangerous if the client is larger, stronger, or faster than the therapist, parent, or teacher. Because of the difficulties inherent in some extinction-based procedures, further research is needed to evaluate procedures that may attenuate extinction-induced phenomena. Some possible directions for future investigations may include evaluating the effects of different reinforcement schedules on behavior in extinction (to ensure that access to reinforcement is available), reinforcer substitution during extinction (in cases when reinforcers maintaining aberrant behavior are inappropriate and cannot be delivered), and motivational operations (to alter the reinforcing efficacy of consequences maintaining aberrant behavior). For example, if a client exhibits aberrant behavior maintained by escape from instructional demands, it may be important to identify the aversive dimensions of the demand context (Smith, Iwata, Goh, & Shore, 1995) in order to reduce the likelihood of evoking escape behavior during instructional procedures (e.g., Dunlap, Kern-Dunlap, Clarke, & Robbins, 1991).

Functional Analysis

237

Although functional analysis-based interventions are sometimes difficult to implement, it is not clear that acceptable alternative approaches will achieve comparable effects. That is, unless default technologies such as punishment or sedation are embraced, the adoption of treatments based on behavioral function may be necessary to address problem behavior adequately in many cases. That it may be difficult or inconvenient to implement such procedures may thus be seen as a resource allocation issue; serious attempts to remediate complex behavior disorders may simply require dedication of increased professional, supervisory, and other resources. Further, behavioral procedures that are not based on a functional analysis may not be any more acceptable (from the practitioner's viewpoint) than procedures that are based on a functional analysis. However, treatment acceptability issues, and how they relate to treatment efficacy, have not been well-studied in the functional analysis literature (Reimers, Wacker, Derby, & Cooper, 1995).

Difficulties with uncontrolled sources of reinforcement. Another potential limitation is that functional analyses sometimes fail to identify events that maintain problem behavior. Although there are several reasons that a functional analysis may not identify specific sources of reinforcement (some of which will be discussed later in this paper), automatic reinforcement creates a unique set of problems for treatment. Automatic reinforcement occurs when a behavior produces reinforcing stimulation independent of the social environment (Vaughn & Michael, 1982). Although a functional analysis may reveal that target behaviors persist in the absence of social contingencies, specific automatic reinforcers are rarely empirically identified. Thus, although we may conclude that SIB occurring only in an alone condition (e.g., Cowdery et al., 1990) is not maintained by social reinforcement, the exact nature and source of reinforcement for SIB remains unclear. If the source of reinforcement cannot be controlled, it cannot be identified (except through inference). Conversely, if the source of reinforcement cannot be identified, it cannot be controlled during treatment. A failure to identify specific sources of reinforcement is a serious issue from a clinical standpoint because the practitioner's ability to develop and implement maximally effective differential reinforcement procedures is limited (e.g., the arrangement shown in the upper panel in Figure 1); that is, if maintaining variables are not identified, treatment success depends on the identification of reinforcers that are more potent than those reinforcers produced by the aberrant behavior - - and remain more potent over time. Several hypotheses have emerged from attempts to identify specific sources of automatic reinforcement for SIB, including perceptual reinforcement (Lovaas, Newsom, & Hickman, 1987), endogenous opiate production (Sandman, Barron, & Colman, 1990), and automatic pain attenuation (Cataldo & Harris, 1982), among others (see Vollmer, 1994, for a review). Although recent epidemiological data show that aberrant behavior maintained

238

T. R. Vollmer and R. G. Smith

independent of the social environment is not rare (Derby et al., 1992; Iwata et al., 1994), treatment evaluations of automatically reinforced behavior are not commonly reported in functional analysis studies (Vollmer, Marcus, & LeBlanc, 1994). Because clinical treatments for automatically reinforced behavior seem to be underrepresented in the literature, evaluating the various hypotheses related to automatic reinforcement is an important area for current and future clinical research. For example, Kennedy and Souza (1995) evaluated a case in which a young man engaged in self-injurious eye poking. The behavior was shown (via functional analysis) to occur only when the participant was not receiving stimulation (i.e., during an alone condition). Hypothesizing that the eye poking was producing visual stimulation, the researchers effectively treated the behavior by disrupting the hypothesized contingency with eye goggles and providing alternative visual stimulation in the form of video games. The results were consistent with the interpretation of automatic visual stimulation as a source of reinforcement for the particular client. The study is significant because it not only provides a model for isolating automatic sources of reinforcement, but directly links such an assessment to intervention. To date, other possible sources of automatic reinforcement have not been well studied using functional analysis methods. Nonetheless, using functional analysis as an assessment method for automatically reinforced behavior is sound logic in principle. If SIB is hypothesized to be maintained by endogenous opioid production, for example, the alone condition of a functional analysis should serve as an appropriate baseline for medication evaluations using opiate antagonists, such as naltrexone. When the activity of endogenous opioids is blocked, an extinction effect is predicted if the production of endogenous opioids is in fact serving as reinforcement. Similarly, if pain attenuation is a hypothesized source of automatic reinforcement, the alone condition would serve as an appropriate baseline to test the effects of analgesics (for toothaches, etc.), antibiotics (for infections), or antihistamines (for allergies). Finally, if specific sources of sensory reinforcement can be identified (e.g., tactile, visual, auditory), it may be possible to identify substitutable reinforcers through systematic stimulus preference assessments (Favell, McGimsey, & Shell, 1982; Green & Freed, 1993). Difficulties in conducting assessments due to time and resource constraints.

Another practical limitation is that functional analyses can be extremely labor intensive and time consuming. Labor intensiveness and time constraints are both factors that have steered clinicians away from the method in favor of alternative types of assessments (Northup et al., 1991). In short, criticisms of using functional analyses for treatment prescription have taken two interrelated forms: (a) the method is time consuming and cumbersome, and (b) there may be alternative assessment methods that would yield adequate information to begin evaluating function-based interventions (Sturmey, 1995).

Functional Analysis

239

At one level, the issue of time constraints is a superfluous one, which belittles the role of a practicing psychologist or behavior analyst. Medical patients would not be denied evaluation of a life-threatening illness requiting extensive physician/patient interactions based on time constraints. Rather, the solution would be to hire more physicians or to shift priorities of hospital personnel. Similarly, if serious criminal behavior (such as rape or aggression) requires extensive judicial evaluation, no citizen (victim or defendant) would be denied the time-consuming due course of the law. It follows then, if a behavior problem displayed by an individual with developmental disabilities is sufficiently dangerous and intractable and sources of reinforcement for the behavior have been difficult to identify, the client and the practitioner have the right and ethical obligation to afford whatever services are necessary to complete a functional analysis (National Institues of Health, 1989). Thus, time constraints per se are not defensible objections to functional analyses unless other methods are shown to be equally effective. At a second level, if altemative forms of assessment methods could prescribe effective interventions, and do so more efficiently, they should be evaluated and applied. If a medical diagnostician develops a 15-min evaluation of an illness, and the evaluation is as reliable and valid as a 40-h evaluation, prolonged evaluation is unjustifiable from a clinical perspective. Similarly, if questionnaires, brief functional analyses, or rating scales can be developed that are reliable and valid, clinical applications of extended functional analyses would be unjustified. However, significant problems have arisen with the reliability and validity of some alternative assessment formats (e.g., ratings scales and questionnaires). For example, Durand and Cfimmins (1988) developed the Motivational Assessment Scale (MAS), which contains a series of questions designed to isolate the circumstances under which serious behavior problems occur. In principle, the value of such a scale is not questioned; but research has shown that the MAS yields poor interrater reliability with some groups of responders (e.g., Zarcone, Rodgers, Iwata, Rourke, & Dorsey, 1991). Future research should continue to refine questionnaires and rating scales in an effort to improve reliability and to compare the results to those of experimental analyses. As an alternative to verbal reports, some practitioners have used the logic of a functional analysis in settings that require time-restricted evaluations. For example, Northup et al. (1991) conducted analog sessions based on the procedures described by Iwata et al. (1982/1994), in an outclinic setting. The assessments were completed during 90-min clinic visits and were shown to isolate specific contingencies of reinforcement for aberrant behavior including aggression and self-injury. Subsequent research has shown that brief assessments can prescribe treatments that are effective and remain effective for extended periods of time (e.g., Northup et al., 1994). To date, there have been no large scale studies comparing the outcome of brief assessments to more traditional assessments, but preliminary research suggests that brief assessment outcomes more closely match extended assessment outcomes than do MAS

240

T. R. Vollmer and R. G. Smith

assessments (Rodgers, Zarcone, & Iwata, 1990). However, data also suggest that brief assessments are less likely than extended analyses to identify behavioral functions (Derby et al., 1992; Iwata et al., 1994). If reliable and valid questionnaires or brief assessment procedures can be developed, it does not necessarily follow that extensive experimental analyses are no longer needed. In short, clinical evaluation is only one purpose of a functional analysis. If future research can eliminate the need for functional analyses in clinical settings, there may still be a need for functional analysis methods for the purposes of scientific investigation. In the next section, we will address functional analysis as a purely research method.

F U N C T I O N A L ANALYSIS AS A R E S E A R C H M E T H O D Although clinical assessment often is the primary purpose of a functional analysis, the method also represents a scientific preparation. Consider the case of SIB; prior to Carr's (1977) paper and Iwata et al.'s (1982/1994) study, little was known about why SIB occurs. Clinical research had shown that some interventions were quite effective in reducing SIB (e.g., Foxx & Azrin, 1973), but essentially scientific questions about the functional properties of SIB were left to biological laboratories. Such a separation of clinical and basic research goals made sense because the traditional function of basic science was laboratory work and the traditional function of clinical research was field work. Functional analysis, however, represents a unique merger of basic and applied science: we now know more about basic processes related to SIB, and information about those basic processes has been useful in developing effective intervention. In other natural sciences, the importance of gaining a fundamental understanding of the subject matter is generally accepted, independent of immediate demonstrations of practical utility. Thus, functional analysis may be useful for the elucidation of basic principles involved in a range of socially significant behaviors - - absent immediate considerations about treatment of those behaviors. In this section we will discuss some scientific contributions of functional analysis and current directions for research.

Functional Analysis of Diverse Response Topographies Functional analysis research has shown clearly that SIB can be sensitive to attention, escape, and tangible stimuli as reinforcers. In other words, for some people SIB occurs specifically because it produces one or more of those environmental consequences. One extension of previous work in functional analysis would be to evaluate the effects of environmental consequences that may serve as reinforcement for other behavior problems. Indeed, methods similar to those of Iwata et al. (1982/1994) recently have been used to demonstrate oper-

Functional Analysis

241

ant functions for classroom disruption (Northup et al., 1995), breath holding (Kern, Mauk, Marder, & Mace, 1995), tantrums (Vollmer et al., 1996), and pica (Mace & Knight, 1986), among others. Also, for many years, operant analyses have been proposed for other clinical problems including disruptive behavior in the elderly (Burgio & Burgio, 1986), childhood aggression (Patterson, Littman, & Bficker, 1967), and delusional verbal behavior (Liberman, Tcigen, Patterson, & Baker, 1973). It is conceivable that systematic replications of existing operant methodologies could extend current understanding of serious and disturbing behavior disorders in addition to the more well researched areas, such as SIB. Systematic replications of functional analysis methods to new behavioral topographies may require special considerations. Carr's (1977) discussion of the SIB literature pointed to specific environmental consequences that appeared to function as reinforcement - - accounts that were supported by years of behavioral research. It should be recognized that other problem behaviors are not necessarily maintained by similar environmental variables. For example, a client's verbal reports of auditory hallucinations may be increased by the attention they produce from others, but they may also be reports occasioned by very real and disturbing private stimuli. Discovery of such functional relations would have scientific value, as well as important treatment implications. Similarly, the set of consequences typically evaluated in SIB research (e.g., attention, tangibles, and escape) may need to be expanded for other behavioral topographies. For example, aggression appears to be sensitive to attention (Northup et al., 1991), escape (Carr, Newsom, & Binkoff, 1980), and tangible stimuli (Patterson et al., 1967) as reinforcers. However, aggression also appears to serve a phylogenic function insofar as animals will behave aggressively (and reflexively) in response to extreme aversive stimulation (Ulrich & Azrin, 1962). Further, the role of imitation in aggression has been well documented (e.g., Bandura & Waiters, 1963). Thus, adaptation of the SIB assessment model to investigate other behavior problems has merit if those behavior problems have been shown to respond to similar operant contingencies; but, the assessment methods should remain flexible enough to integrate new information about other controlling variables. Ideally, comprehensive hypotheses could be set forth based on integrated literature reviews to support the development of experimental assessment preparations. Other important considerations should be evaluated before attempting to replicate functional analysis methods with infrequently studied behavior problems. When a behavior occurs at a low frequency, when a behavior is too dangerous to reinforce or allow (such as aberrant sexual behavior), or when the functional properties of behavior can be identified by other means, experimental analysis may be contraindicated. Of course, these same considerations are relevant to more traditionally studied behavioral topographies, such as SIB.

242

T. R. VoUmerand R. G. Smith

Functional Analysis of Basic Behavioral Processes

In addition to evaluating various problematic response topographies, functional analysis is frequently used to evaluate basic behavioral processes. For example, extinction has been rarely studied in humans because the reinforcers supporting aberrant behavior have, until recently, rarely been identified. With the advent of functional analysis methods, specific reinforcing consequences are not only identified, they are also intentionally presented during baseline. Thus, by subsequently withholding those reinforcing consequences, the effects of extinction can be evaluated (e.g., Mazaleski et al., 1993). Treatments prescribed by functional analyses often represent a type of concurrent schedule of reinforcement (see Figure 1), in which two or more alternatives for reinforcement are available simultaneously. Thus, the applicability of the matching equation (Baum, 1974; Hemnstien, 1970) to human behavior has become a viable area of research that links applied and basic science. The matching equation states that the relative rate of responding to one alternative (i.e., one reinforcement schedule) will match the relative rate of reinforcement for responding for that alternative. Further, research with humans and nonhumans has shown that variables such as delay to reinforcement, frequency of reinforcement, magnitude of reinforcement, and quality of reinforcement will influence choice behavior (McDowell, 1988; Neef, Shade, & Miller, 1994). These variables are particularly appropriate for functional analysis research: the matching law should be useful in predicting relative rates of problem behavior and appropriate alternatives, based on knowledge about the parameters of reinforcement for each. For example, if aggression results in immediate attention but sign language results in intermittent and delayed attention, aggression may be expected to occur more frequently than sign language because the schedule of reinforcement is more favorable. Future research could evaluate the effects of reinforcement parameters among alternatives by systematically manipulating variables such as rate, schedules, and delays to reinforcement. Although such investigations could reasonably be characterized as basic research on human behavior, they also may have important clinical implications. Evaluating the circumstances leading to treatment erosion can provide information about the integrity with which treatment must be implemented to maintain desired effects. Functional analysis baselines also represent an ideal method for evaluating the effects of molar or complex variables. Sturmey (1995) criticized functional analysis methods as being limited to evaluations of immediate antecedent and consequent variables. We would argue that the opposite is true: functional analysis baselines allow an experimenter to hold antecedent and consequent variables constant, which may be a requirement for studying progressively more complex environmental operations. For example, in a functional analysis of aggression, O'Reiily (1995) conducted two instructional demand baselines that were identical except that some sessions were conducted after the client

Functional Analysis

243

had more than 5 h of sleep and other sessions were conducted when the client had less than 5 h of sleep. O'Reilly showed that less sleep was correlated with consistently higher levels of escape-maintained aggression. Smith et al. (1995) used a functional analysis approach to evaluate potential motivational variables associated with escape-maintained SIB. By continuing to reinforce SIB with escape, the effects of antecedent variables such as task novelty, rate of task trials, and duration of instructional sessions were investigated. Results showed that these variables altered the reinforcing effects of escape for several subjects. Although immediate implications of these outcomes for treatment were not shown, possible applications could include manipulation of motivational variables as antecedent intervention or in combination with extinctionbased treatments.

Functional Analysis as a Participant Screening Method

Another role of functional analysis as a research method is to identify individuals whose behavioral functions are appropriate to address specific research questions. For example, Iwata et al. (1990) were interested in evaluating escape extinction, largely because little research had been conducted on the suppression of behavior maintained by negative reinforcement. In Phase 1 of the study, seven individuals were selected for the escape extinction evaluation based on the results of functional analyses. If clients did not display escape behavior, they were presumably treated in other ways or participated in other studies. Thus, functional analysis as a form of assessment ensured that the participants in the study were appropriate for the analysis. Further, the reinforcer (escape) and the schedule of reinforcement (continuous) were controlled. If functional analysis served only a clinical purpose, the study could be criticized because it is unlikely that all SIB outside of the laboratory setting resulted in escape and it is unlikely that the teachers (the experimenters) were presenting exactly the same instructions the participants received outside the laboratory context. But, because the study had a more basic purpose (to evaluate escape extinction), it was essential for the researchers to show: (a) a differential responsiveness to escape contingencies, and (b) reductions in SIB when escape contingencies were no longer provided. Hagopian et al. (1994) were interested in evaluating the operative components of noncontingent positive reinforcement procedures. As such, a preintervention functional analysis identified four participants whose disruptive behavior was maintained by attention. Similarly, Vollmer, Marcus, and LeBlanc (1994) were interested in evaluating the effects of noncontingent reinforcers on behavior that was insensitive to social contingencies. As such, preintervention functional analyses were conducted to identify individuals whose stereotypy and SIB persisted in the absence of social contingencies. In short, functional analysis provides a convincing screening method by which to

244

T. R. Vollmer and R. G. Smith

include or exclude individuals from participation in a study - - b a s e d on the research question being addressed. Further, functional analysis conditions serve as appropriate baselines because antecedent and consequent variables are known, and can be arranged to maximize contact with the relevant contingency (e.g., Iwata et al., 1994) or to simulate intermittent schedules that occur in the natural environment (e.g., Mace & Lalli, 1991).

Functional Analysis Research as Methodological Refinement

As mentioned previously, not all functional analyses yield conclusive results. Undifferentiated results are a problem because if conclusive results are not obtained, the clinical and basic research roles of the method are undermined. Undifferentiated results occur either when the rate of aberrant behavior is relatively high in more than one assessment condition or when the rate of aberrant behavior is uniformly low across all assessment conditions. Although there are many reasons functional analyses might yield inconclusive results, some of the more common reasons include automatic reinforcement (Vollmer, 1994), interaction effects (Higgins Hains & Baer, 1989), multiply controlled behavior (Day, Homer, & O'Neill, 1994; Smith, Iwata, Vollmer, & Zarcone, 1993), and idiosyncratic sources of reinforcement (Carr, 1994). Some recent functional analysis research has been conducted for the sole purpose of refining methods to interpret undifferentiated outcomes or to minimize the likelihood of obtaining undifferentiated outcomes. We have discussed the clinical implications of automatic reinforcement previously. From the standpoint of experimental design, one important goal of a functional analysis is to distinguish undifferentiated results produced by automatic reinforcement versus undifferentiated results produced by other factors such as interaction effects between experimental conditions. If a behavior occurs exclusively in an alone or no-interaction condition and persists without extinction, it is reasonable to argue that the behavior is serving to produce reinforcing stimulation in the absence of other sources of reinforcement (Cowdery et al., 1990). However, if a behavior occurs at a relatively constant level across all or more than one experimental assessment condition, it is difficult to ascertain whether the behavior persists because it produces automatic reinforcement or because the effects of socially mediated reinforcement during one condition carry over to other conditions. In an attempt to separate the effects of automatic reinforcement and interaction, Vollmer, Marcus, Ringdahl, and Roane (1995) exposed participants whose original assessments yielded undifferentiated outcomes to several consecutive no-interaction (alone) sessions. For those participants whose behavior was maintained by social reinforcement, behavior extinguished during the no-interaction sessions. For other participants, aberrant behavior persisted across many sessions in the absence of social consequences, suggesting that the behavior was not maintained by socially mediated

Functional Analysis

245

contingencies of reinforcement. Another technique for evaluating possible interaction effects involves plotting within-session response patterns (e.g., minute-by-minute frequencies), which may indicate whether carryover or extinction effects are occurring over the course of a single session (Cooper, Wacker, Sasso, Reimers, & Donn, 1990). For example, Vollmer, Iwata, Zarcone, Smith, and Mazaleski (1993b) showed that high rates of SIB during alone and play conditions for one participant were a direct result of reinforcement effects from preceding attention (positive reinforcement) sessions. This was demonstrated by evaluating the within-session patterns of responding, which showed an extinction burst of SIB during all sessions that followed attention sessions. In addition to automatic reinforcement and interaction effects, behavior that is sensitive to more than one general source of reinforcement may produce undifferentiated functional analysis results (Smith et al., 1993). For instance, aberrant behavior may occur at high rates during demand conditions because escape is a functional reinforcer, but may also occur at high rates during attention sessions because attention is a functional reinforcer. Two recent studies have developed methods for evaluating multiply controlled behavior by progressively introducing treatments for each hypothesized function (Day et al., 1994; Smith et al., 1993). For example, with one participant, Smith et al. showed that SIB occurred at high levels in an alone condition and in an instructional demand condition. During treatment, the participant was first given access to highly preferred alternative stimuli (beads). Access to the beads suppressed SIB during the alone condition but had little effect on SIB during the demand condition. Next, escape extinction was introduced during the demand condition and escape behavior eventually was reduced. These results showed that inconclusive assessment results could be clarified by using the relevant assessment conditions as baselines from which to compare the effects of relevant treatment conditions. Finally, undifferentiated functional analyses may result from a failure to identify idiosyncratic sources of reinforcement. A client may display very few or no instances of behavior during an assessment because the relevant reinforcers or other environmental features are not included in the analysis. For example, a particular client may only engage in escape behavior when he is asked to take a shower or wash up (perhaps water is an aversive stimulus). If the escape condition during a functional analysis does not happen to include showers or washing, the escape function may go unrecognized. Similarly, a client may engage in aberrant behavior that is reinforced by access to food. If functional analysis sessions are conducted after lunch or do not include food access conditions, the operative reinforcers may go undetected. The issue of idiosyncratic sources of reinforcement is most critical from a clinical perspective because reinforcers must be identified for a given client in order to develop effective interventions. As such, more research should be conducted linking descriptive information from observations in the natural environment and interviews to the conditions

246

T. R. Vollmer and R. G. Smith

used in a functional analysis (Mace & Lalli, 1991; O'Neill et al., 1990). The issue of idiosyncratic sources of reinforcement is less critical from a basic research standpoint, because functional analysis studies are often designed to evaluate general behavioral processes (such as extinction) rather than responsiveness to specific and unusual sources of stimulation. CONCLUSIONS Functional analysis research, although widely disseminated, is a young field. Many of the limitations that have been noted in prior commentaries (e.g., Sturmey, 1995) are limitations that may be addressed through future research. Other limitations may be viewed as problems only if the role of functional analysis is limited to clinical application. We have argued that the role of functional analysis is at least twofold: for clinical application and for more basic research purposes. That these two aims are sometimes interrelated is a unique contribution of functional analysis research. Further, studies in the area of functional analysis should be evaluated along either (or both) dimensions. For example, the development of a reliable and valid questionnaire may be of high clinical significance but may contribute little to the understanding of basic behavioral processes. An evaluation of escape extinction may contribute significantly to an understanding of basic behavioral processes but may represent an incomplete clinical intervention for any given client. But, the clinical and research themes in functional analysis studies are usually symbiotic. REFERENCES Bandura, A. & Waiters, R. H. (1963). Social learning and personality development. New York: Holt, Rinehart & Winston. Baum, W. M. (1974). On two types of deviations from the matching law: Bias and undermatching. Journal of the Experimental Analysis of Behavior, 22, 231-242. Burgio, L. D., & Burgio, K. L. (1986). Behavioral gerontology: Application of behavioral methods to the problems of older adults. Journal of Applied Behavior Analysis, 19, 321-328. Carl E. G. (1977). The motivation of self-injurious behavior: A review of some hypotheses. Psychological Bulletin, 84, 800-816. Carr, E. G. (1994). Emerging themes in the functional analysis of problem behavior. Journal of Applied Behavior Analysis, 27, 393-399. Carr, E. G., & Durand, V. M. (1985). Reducing behavior problems through functional communication training. Journal of Applied Behavior Analysis, 18, 11 I - 126. Cart, E. G., Newsom, C. D., & Binkoff, J. (1980). Escape as a factor in the aggressive behavior of two retarded children. Journal of Applied Behavior Analysis, 13, 101-117. Cataldo, M. F., & Harris, J. (1982). The biological basis for self-injury in the mentally retarded. Analysis and Intervention in Developmental Disabilities, 2, 21-39. Cooper, L., Wacker, D., Sasso, G., Reimers, T., & Donn, L. (1990). Using parents as therapists to assess the appropriate behavior of their children: Application to a tertiary diagnostic clinic. Journal of Applied Behavior Analysis, 23, 285-296. Cowdery, G. E., Iwata, B. A., & Pace, G. M. (1990). Effects and side effects of DRO as treatment for self-injurious behavior. Journal of Applied Behavior Analysis, 23, 497-506.

Functional Analysis

247

Day, M. H., Homer, R. H., & O'Neill, R. E. (1994). Multiple functions of problem behaviors: Assessment and intervention. Journal of Applied Behavior Analysis, 27, 279-289. Derby, K. M., Wacker, D., Sasso, G., Steege, M., Northup, J., Cigrand, K., & Asmus, J. (1992). Brief functional assessment techniques to evaluate aberrant behavior in an outpatient setting: A summary of 79 cases. Journal of Applied Behavior Analysis, 25, 713-721. Dunlap, G., Kern-Dunlap, L., Clarke, S., & Robbins, E R. (1991). Functional assessment, curricular revision, and severe behavior problems. Journal of Applied Behavior Analysis, 24, 387-397. Durand, V. M., & Crimmins, D. B. (1988). Identifying variables maintaining self-injurious behavior. Journal of Autism and Developmental Disorders, 18, 99-117. Favell, J. E., McGimsey, J. E, & Schell, R. M. (1982). Treatment of self-injury by providing alternate sensory activities. Analysis and Intervention in Developmental Disabilities, 2, 83-104. Foxx, R. M., & Azrin, N. H. (1973). The elimination of autistic self-stimulatory behavior by overcorrection. Journal of Applied Behavior Analysis, 6, 1-14. Green, L. & Freed, D. E. (1993). The substitutability of reinforcers. Journal of the Experimental Analysis of Behavior, 60, 141-158. Hagopian, L. P., Fisher, W. W., & Legacy, S. M. (1994). Schedule effects of noncontingent reinforcement on attention-maintained destructive behavior in identical quadruplets. Journal of Applied Behavior Analysis, 27, 317-325. Hermstein, R. J. (1970). On the law of effect. Journal of the Experimental Analysis of Behavior, 13, 243-266. Higgins Hains, A., & Baer, D. M. (1989). Interaction effects in multielement designs: Inevitable, desirable, and ignorable. Journal of Applied Behavior Analysis, 22, 57-69. Homer, R. H. (1994). Functional assessment: Contributions and future directions. Journal of Applied Behavior Analysis, 28, 401-404. lwata, B. A., Pace, G. M., Dorsey, B. E, Zarcone, J. R., VoUmer, T. R., Smith, R. G., Rodgers, T. A., Lerman, D. C., Shore, B. A., Mazaleski, J. L., Goh, H. L., Cowdery, G. L., Kalsher, M. J., McCosh, K. C., and Willis, K. D. (1994). The function of self-injurious behavior: An experimental-epidemiological analysis. Journal of Applied Behavior Analysis, 27, 215-240. Iwata, B. A., Slifer, K. J., Bauman, K. E., & Richman, G. S. (1982/1994). Toward a functional analysis of self-injury. Journal of Applied Behavior Analysis, 27, 197-209. (Reprinted from Analysis and Intervention in Developmental Disabilities, 2, 1-20, 1982). lwata, B. A., Pace, G. M., Kalsher, M. J., Cowdery, G. E., & Cataldo, M. E (1990). Experimental analysis and extinction of self-injurious escape behavior. Journal of Applied Behavior Analysis, 23, 11-27. Kern, L., Mauk, J. E., Marder, T. J., & Mace, E C. (1995). Functional analysis and intervention for breath-holding. Journal of Applied Behavior Analysis, 28, 339-340. Kennedy, C. H., & Souza, G. (1995). Functional analysis and treatment of eye poking. Journal of Applied Behavior Analysis, 28, 27-37. Lennox, D. B., Miltenberger, R. G., & Donnelly, D. R. (1987). Response interuption and DRL for the reduction of rapid eating. Journal of Applied Behavior Analysis, 20, 279-284. Liberman, R. P., Teigen, J., Patterson, R., & Baker, V. (1973). Reducing delusional speech in chronic, paranoid schizophrenics. Journal of Applied Behavior Analysis, 6, 57-64. Lovaas, O. I., Newsom, C. D., & Hickman, C. (1987). Self-stimulatory behavior and perceptual reinforcement. Journal of Applied Behavior Analysis, 2@, 45-68. Mace, F. C., & Knight, D. (1986). Functional analysis and treatment of severe pica. Journal of Applied Behavior Analysis, 19, 411-416. Mace, E C., Browder, D., & Lyn, Y. (1987). Analysis of demand conditions associated with stereotypy. Journal of Behavior Therapy and Experimental Psychiatry, 18, 25-3 I. Mace, E C., & Lalli, J. S. (1991). Linking descriptive and experimental analyses in the treatment of bizarre speech. Journal of Applied Behavior Analysis, 24, 553-562. Mace, F. C., Lalli, J. S., & Pinter-Lalli, E. (1991). Functional analysis and the treatment of aberrant behavior. Research in Developmental Disabilities, 12, 155-180.

248

T. R. Vollmer and R. G. Smith

Marcus, B. A., & Vollmer, T. R. (1995). Effects of differential negative reinforcement on disruption and compliance. Journal of Applied Behavior Analysis, 2,8, 229-230. Mazaleski, J. L., Iwata, B. A., Vollmer, T. R., Zareone, J. R., & Smith, R. G. (1993). Analysis of the reinforcement and extinction components in DRO contingencies with self-injury. Journal of Applied Behavior Analysis, 26, 143-156. McDowell, J. J. (1988). Matching theory in natural human environments. The Behavior Analyst, 11, 95-109. National Institutes of Health. NIH consensus development conference on the treatment of destructive behaviors in persons with developmental disabilities. Bethesda, MD: Author. Neef, N. A., & Iwata, B. A. (1994). Current research on functional analysis methodologies: An introduction. Journal of Applied Behavior Analysis, 28, 21 I-214. Neef, N. A., Shade, D., & Miller, M. S. (1994). Assessing influential dimensions of reinforcers on choice in students with serious emotional disturbance. Journal of Applied Behavior Analysis, 27, 569-574. Northup, J., Broussard, C., Jones, K., George, T., Vollmer, T. R., & Herring, M. (1995). The differential effects of teacher and peer attention on the disruptive classroom behavior of three children with a diagnosis of attention deficit hyperactivity disorder. Journal of Applied Behavior Analysis, 28, 277-228. Northup, J., Wacker, D. P., Sasso, G., Steege, M., Cigrand, C., Cook, J., & DeRaad, A. (1991). A brief functional analysis of aggressive and alternative behavior in an outclinic setting. Journal of Applied Behavior Analysis, 24, 509-521. Northup, J., Wacker, D. P., Berg, W. K., Kelly, L., Sasso, G., & DeRaad, A. (1994). The treatment of severe behavior problems in school settings using a technical assistance model. Journal of Applied Behavior Analysis, 27, 33-47. O'Neill, R. E., Homer, R. H., Albin, R. W., Storey, K., & Sprague, J. R. (1990). Functional analysis of problem behavior: A practical assessment guide. Pacific Grove, CA: Brooks/Cole. O'Reilly, M. E (1995). Functional analysis and treatment of escape-maintained aggression correlated with sleep deprivation. Journal of Applied Behavior Analysis, 28, 225-226. Patterson, G. R., Littman, R. A., & Bricker, W. (1967). Assertive behavior in children: A step toward a theory of aggression. Monographs of the Society for Research in Child Development, 32, 1-12. Reimers, T. M., Wacker, D. P., Derby, K. M., & Cooper, L. J. (1995). Relation between parental attributions and the acceptability of behavioral treatments for their child's behavior problems. Behavioral Disorders, 20, 171-178. Rodgers, T. A., Zarcone, J. R., & Iwata, B. A. (1990). A comparison of methods for conducting functional analysis of self-injurious behavior. Paper presented at the 16th annual convention of the Association for Behavior Analysis, Nashville, TN. Sandman, C. A., Barron, J. L., & Colman, H. (1990). An orally administered opiate blocker, Naltrexone, attenuates self-injurious behavior. American Journal on Mental Retardation, 95, 84-92. Skinner, B. E (1953). Science and human behavior. New York: Macmillan. Smith, R. G., Iwata, B. A., Goh, H. L., & Shore, B. S. (1995). Analysis of establishing operations for self-injury maintained by escape. Journal of Applied Behavior Analysis, 2,8, 515-535. Smith, R. G., lwata, B. A., Vollmer, T. R., & Zarcone, J. R. (1993). Experimental analysis and treatment of multiply controlled self-injury. Journal of Applied Behavior Analysis, 26, 183-196. Sturmey, P. (1995). Analog baselines: A critical review of the methodology. Research in Developmental Disabilities, 16, 269-284. Ulrich, R. E., & Azrin, N. H. (1962). Reflexive fighting in response to aversive stimulation. Journal of the Experimental Analysis of Behavior, 5, 511-520. Vaughn, M. E., & Michael, J. L. (1982). Automatic reinforcement: An important but ignored concept. Behaviorism, 10, 217-228.

Functional Analysis

249

Vollmer, T. R. (1994). The concept of automatic reinforcement: Implications for behavioral research in developmental disabilities. Research in Developmental Disabilities, 15, 187-207. Vollmer, T. R., Iwata, B. A., Zarcone, L R., Smith, R. G., & Mazaleski, J. L. (1993a). The role of attention in the treatment of attention-maintained self-injurious behavior: Noncontingent reinforcement (NCR) and differential reinforcement of other behavior (DRO). Journal of Applied Behavior Analysis, 26, 9-21. Vollmer, T. R., Iwata, B. A., Zarcone, J. R., Smith, R. G., & Mazaleski, J. L. (1993b). Within-session patterns of self-injury as indicators of behavioral function. Research in Developmental Disabilities, 14, 479-492. Vollmer, T. R., Marcus, B. A., & LeBlanc, L. A. (1994). Treatment of self-injury and hand mouthing following inconclusive functional analyses. Journal of Applied Behavior Analysis, 27, 331-343. Voilmer, T. R., Marcus, B. A., & Ringdahl, J. E. (1995). Noncontingent escape as treatment for self-injurious behavior maintained by negative reinforcement. Journal of Applied Behavior Analysis, 28, 15-26. Vollmer, T. R., Marcus, B. A., Ringdahl, J. E., & Roane, H. S. (1995). Progressing from brief assessments to extended functional analyses in the evaluation of aberrant behavior. Journal of Applied Behavior Analysis, 28, 561-576. Vollmer, T. R., Northup, J., Ringdahl, J. E., LeBlanc, L. A., & Chauvin, T. M. (1996). Functional analysis of severe tantrums displayed by children with language delays: An outclinic assessment. Behavior Modification, 20, 97-115. Wacker, D. P., Steege, M. W., Northup, J., Sasso, G., Berg, W., Reimers, T., Cooper, L, Cigrand, K., & Donn, L. (1990). A component analysis of functional communication training across three topographies of severe behavior problems. Journal of Applied Behavior Analysis, 23, 417-429. Zareone, J. R., Iwata, B. A., Vollmer, T. R., Jagtiani, S., Smith, R. G., & Mazaleski, J. L. (1993). Extinction of self-injurious escape behavior with and without instructional fading. Journal of Applied Behavior Analysis, 26, 353-360. Zarcone, J. R., Rodgers, T. A., Iwata, B. A., Rourke, D., & Dorsey, M. E (1991). Reliability analysis of the motivational assessment scale: A failure to replicate. Research in Developmental Disabilities, 12, 349-360.