zy zyxwvutsrq zyxwvutsrq MENTAL RETARDATION AND DEVELOPMENTAL DISABILITIES RESEARCH REVIEWS 7:94-98 (7995) BIOLOGICAL SETTING EVENTS FOR SELF-INJURY Edward G Carr and Christopher E Smith State University of New York at Stony Brook (E.G.C.) and Developmental Disabilities Institute (C.E.S.), Stony Brook, New York Self-injurious behavior typically occurs in response t o specific antecedent stimuli that predict the occurrence of such desirable consequences of the behavior as obtaining attention from others, escaping aversive situations, and securing preferred foods, objects, and activities Setting events constitute an additional controlling variable, altering the probability that a specific antecedent stimulus will evoke self-injury We discuss the influence of several biological factors, including menses, otitis media, fatigue, allergies, and constipation, that may serve as setting events We also present a model which suggests that these events alter the functional properties of the antecedent stimuli that control self-injurious behavior, thereby strengthening the specific consequences that maintain the behavior One implication of this model is the likelihood that effective intervention will have to have multiple components, addressing both the biological and environmental variables that control the behavior Asecond implication is that greater collaboration between medical and psychological or educational practitioners will be necessary in order to address the multiple factors that affect selfinjury D 1995 Wiley-Liss, Inc zyxwvutsrqp M R D D Research Reviews 1: 94-98 ~~ much more frequent, but when they withhold attention, the level of self-injury dramatically decreases [Lovaas et al., 1965; Carr and McDowell, 19801 Similarly, the escape function has been demonstrated in studies showing that when hstrating task demands are withdrawn in response to self-injury, the behavior increases, but that when such demands are not withdrawn after display of the behavior, self-injury becomes much less likely to occur [Iwata et al., 1982; Iwata et al., 19901 Finally, the tangible-seeking function of self-injury has been demonstrated Studies have shown that presentation of desired tangibles after self-injurious behavior causes an increase in the f?equency of such behavior [Derby et al., 19921 Other functions ofself-injury that have been demonstrated include, for example, avoidance of social situations [Taylor and Carr, 19921 and seeking sensory stimulation (e.g., auditory, visual, and gustatory) [Favell et al., 1982; Rincover and Devaney, 19821 However, the bulk of the relevant research has examined attention, escape, and tangbles as sources of reinforcement for self-injury Because self-injury typically is purposeful, it does not occur randomly Rather, it is closely associated with antecedent stimuli that predict whether the behavior is likely to be followed by desirable consequences Thus, a low level of attention can function as an antecedent stimulus that triggers episodes of self-injury [Carr and Durand, 19851 The process underlying this outcome is likely to involve a history in which an individual has repeatedly experienced the reinstatement of high levels of attention following the display of self-injury Over time, the individual learns that exhibiting self-injurious behavior in the presence of low levels of attention from others “pays off’ in the sense that it is quickly and reliably followed by nurture, support, and expressions of concern from others It is likely that a similar process is responsible for self-injury that serves the function of escape or attaining tangibles For example, in the case of escape, task demands, including those involving academic or work activities, sometimes function as antecedent stimuli that trigger episodes ofself-injury [Can et al., 19761 This may be related to a history in which an individual has repeatedly experienced the removal of frustrating, boring, or effortful tasks following the display of self-injury Over time, the individual learns that such behavior exhibited in the presence of task demands “pays off’ in the sense that the task is quickly and reliably removed [Carr et al., ~ ~ - ~~ ~ Key Words: self-injurious behavior, setting events, developmental disabilities, functional analysis rom a behavioral perspective, self-injury is a function of three sets of variables: consequences, antecedents, and setting events Consequences refer to the effects that self-injury has on others For example, a young boy diagnosed as retarded may engage in head banging One consequence of this behavior is that the boy’s anxiety-stricken mother quickly approaches her child and offers him physical comfort, soothing words, and other forms of attention Alternatively, the boy may start head banging when confronted with a frustrating academic task In consequence, his alarmed teacher withdraws the task, thereby permitting the boy to escape from the unpleasant situation O n another occasion, the boy may exhibit head banging in a toy store The consequence is that his embarrassed father offers him several toys in order to placate him In each case, self-injury serves a particular function or “purpose” for the child The specific consequence of each self-injurious act allows one to infer what purposes the behavior serves-in the examples gwen, attention-seeking, escape from aversive events, and attempting to secure desired tangible items Research supports the idea that individuals generally exhibit self-injury because it produces desirable consequences for them The attention-seeking function has been demonstrated in studies showing that when adults offer children comforting words or pleas to desist from self-injury, the behavior becomes F o 1995 Wiley-Liss, Inc zyxwvu zyxwvuts Address reprint requests to Edward Cam, Department of Psychology, State Unlvenity of New York, Stony Brook, N Y 11794-2500 19911 The research literature is replete with descriptions of other stimuli that trigger self-injury: being teased, receiving negative feedback about task performance, desiring objects that are momentarily inaccessible, and being prompted by a teacher to improve performance on a given task [Carr et al., 1990; O’Neill et al., 1990; Gardner and Sovner, 19941 Although it is clear that self-injury is a joint function of antecedents and consequences, an emerging literature now suggests that a third set of variables, setting events, also has an important role Setting events are broad contextual influences that alter ongoing relationships between antecedent stimuli and responses such as self-injury [Bijou and Baer, 19611 For example, we noted earlier that there &equently is a relationship between antecedent stimuli such as task demands and self-injurious behavior This relationship can be made more or less probable through the influence of various setting events Some setting events are environmental For example, Kennedy and Itkonen [1993] reported that for one woman diagnosed as being retarded, an environmental setting event-use of a specific bus route to school-became associated with an increased probability of self-injurious behavior in the presence of a variety of antecedent stimuli, including self-help and community-based demands In contrast, the absence of the setting event-use of an alternative bus route-was associated with negligible levels of self-injury in the presence of the same types of task demands Other setting events are biological Although these have been frequently alluded to in the literature, they have not yet been systematically analyzed O u r purpose here is to focus on the nature of these biological setting events and propose a model for their operation that can serve as a heuristic basis for subsequent assessment and intervention research Menses A number of studies involving women with psychiatric disorders have described an exacerbation of problems associated with those disorders during the premenstrual phase, the first few days of menstrual flow, or both These problems include an increase in affective disorders such as depression [Endicott et al., 19811, and psychotic episodes [Felthous et al., 19801 Several case studies involving women diagnosed as retarded have also noted an increase in depressive symptoms [Dennerstein et al., 19831, as well as fearfulness and irritability [Altschule and Brem, 19631 associated with menses Most interestingly, a recent study of 24 women diagnosed as retarded reported a positive correlation between menses and occurred at this time Although this correlation is of considerable interest, the lack of a more fine-grained analysis in this study makes it impossible to determine whether the increase in self-injury was triggered by the menses, by a mensesrelated alteration in the response to specific environmental cues, or by some third factor spuriously related to menses Otitis Media Some forms of self-injury, such as head banging, are by no means limited to people with developmental disabilities There have been detailed descriptive accounts of head banging occurring as early as the first year of life in children without disabilities [deLissovoy, 19621 In one study of 374 normal children between the ages of 19 and 32 months, deLissovoy [1961, 19641 observed head banging by 57 children or 15.2% of the sample Interestingly, in the deLissovoy [1962] study, the tendency toward head banging increased in some children when they had colds or other unspecified illnesses In another study, deLissovoy [1963] found an association between otitis media (middle ear infection) and the onset of head banging by young children There is no evidence that children with developmental disabilities are less susceptible to such infection than are other children Because otitis media is so common in infancy and early childhood, one would expect that many children with disabilities develop the condition from time to time and that, as in the general pediatric population, a certain percentage of these children will develop associated head banging Several investigators in the disabilities area have suggested a causal link between otitis media and self-injury [Bailey and Pyles, 1989; Gardner and Sovner, 19941 However, only one group of investigators reported, and only anecdotally, a case documenting the association between head banging and middle ear infection [Gunsett et al., 19891 Moreover, that case involved an adult Given the data from the general pediatric literature and the allusions made to otitis media in the literature on disabilities, the time appears to be right for a systematic experimental analysis of the role this biological factor plays in producing selfinjury zyxwv zyx zyxw zyxwvutsrq Although it is clear that self-injury is a joint function of antecedents and consequences, an emerging literature now suggests that a third set of variables, setting events, also has an important role Setting events are broad contextual influences that alter ongoing rela tionships between antecedent stimuli and responses such as self-inju ry DESCRIPTION OF BIOLOGICAL SETTING EVENTS Self-injurious behavior has been linked to biological setting events associated with every major physiological system: central nervous, gastrointestinal, immune, reproductive, and respiratory pailey and Pyles, 1989; Gunsett et al., 1989; Gardner and Sovner, 19941 Although these linkages have not yet been demonstrated experimentally, the correlational and descriptive evidence is pervasive enough to warrant closer scrutiny by scientists and clinicians MRDD RESEARCH REVIEWS BIOLOGICAL self-injury [Ghaziuddin et al., 19931 Clearly, a variety of problems associated with menses has been identified However, the studies cited were based in large measure on anecdotal data Moreover, only one of these studies involved self-injury Recently, however, a detailed, systematic report on women with mental retardation has described more clearly the association between menses and self-injury [Taylor et al., 19931 The major finding was that the frequency of self-injurious behavior was typically elevated during the early phases of the menstrual cycle (menses, early and late follicular) The vast majority of selfinjurious episodes, which included selfbiting, head banging, and face slapping, SETTINGEVENTS CARRS~SMITH Other Biological Variables Although menses and otitis media are not the only biological factors that have been linked to the occurrence of self-injurious behavior, they are the ones described in greatest detail in the litera- zyxw 95 zyxwvu Fig A conceptual framework for understanding the effects of biological setting events on self-injurious behavior Problem behavior is influenced by context (setting events and trigger stimuli) Setting events alter the likelihood that antecedent stimuli will trigger self injury by changing the value of the consequences (escape, attention, tangibles) of self-injury r zyxwvutsrqponmlkjihgf ture Scattered throughout the literature are references, almost always anecdotal, to other factors The scope and variety of these factors strengthens the argument that biological setting events are pervasive and therefore worth looking at more systematically than has been done to date Fatigue has been suggested as a possible setting event for self-injury A number of variables can induce fatigue: nocturnal sleep deficit, prolonged physical activity, temperature extremes, and lack of sugar, salt, or water in the body For this reason, remediation of problem behavior associated with fatigue should plausibly be linked with the specific variable underlying the fatigue The relationship between fatigue and selfinjury has been observed in populations with developmental disabilities [Gardner et al., 1986; Bailey and Pyles, 19891 However, documentation has been purely anecdotal, leaving unclear the precise relationship between fatigue and selfinjury Allergies have been identified as a factor influencing problem behavior in people without developmental disabilities [e.g., Field, 19811 Interestingly, Gardner [1985] noted similar influences in the case of a young man diagnosed as being severely retarded Careful observation of this person over a long period suggested a relationship between his severe selfinjury, which necessitated the use of restraints, and seasonal allergies Staff were trained to monitor his medical condition and administer antihistamines when appropriate The result was that restraints were no longer necessary and self-injury became infrequent This case study is suggestive, as are other anecdotal accounts of the relationship between allergies and self-injury [Gourash, 1986; Bailey and Pyles, 19891 Some reports indicate that constipation is more common among people with mental retardation than among others [Roy and Simon, 19871 In one study, staff reported that individuals most often engaged in self-injurious behaviors such as hitting themselves in the abdomen when they had distended abdomens and were screaming, which led to the hypothesis that such behavior was a response to pain associated with constipation [Lekkas and Lentino, 19781 Several other case reports have suggested that chronic constipation makes individuals more irritable than is normal and may therefore be a predisposing factor for increased levels of self-injurious behavior such as head banging and self-slapping [Gunsett et al., 1989; Gardner and Sovner, 19941 BIOLOGICAL SETTING EVENTS: A CONCEPTUAL FRAMEWORK Figure illustrates a model for understanding the impact of biological setting events on problem behavior such as self-injury This model brings together the three sets of controlling variables we have described thus far: antecedents (trigger stimuli), consequences, and setting events Consider an antecedent (trigger) stimulus such as an academic demand (e.g., “Tommy, point to the picture of the horses.”) The stimulus may occasionally trigger an episode of self-injurious behavior because, in the past, it has caused the teacher to stop teaching and withdraw the task That is, the consequence of self-injury in the presence of the trigger stimulus is that the child is allowed to escape from a putatively aversive task However, the trigger stimulus does not always evoke self-injury at the same level Instead, it appears that when an individual with disabilities is suffering from some medical condition or particular physiologcal state, self-injury is more likely to occur Thus, in our example, if Tommy is suffering from otitis media, constipation, fatigue, or allergies, he is much more likely to engage in self-injurious behavior when presented with demands Why should this be the case? One current view is that setting events, including the biologcal factors we have described, can alter the aversiveness of antecedent trigger stimuli, thereby increasing the motivation for escape behavior such as self-injury [Michael, 1982; Bailey and Pyles, 1989; Gardner and Sovner, 19941 Our model has considerable face validity given that the zyxwvutsr 96 Summary Our overview of the literature suggests that the relationship between self-injurious behavior and biological factors is pervasive, cutting across a variety ofphysiological states and medical conditions Many medical conditions are mentioned in passing in the literature Despite the suggestive nature of this relationship, the role of biological setting events has not been systematically explored The best studies, and there have been few, present detailed correlational data rather than the results of systematic experimental analyses The substantial majority of reports present only case studies or anecdotes The rudimentary but suggestive data in this field argue in favor of a more detailed and organized approach To that end, we propose a model for exploring the relationship between self-injury and b i o l o g d setting events MRDD RESEARCH REVIEWSBIOLOGICALSETTINGEVENTS zy CARR& SMITH various biological factors we have discussed have in common pain, physical discomfort, or both Thus, the notion is that a mildly aversive antecedent such as a task demand becomes extremely aversive when it occurs in the context of a painful or uncomfortable biologcal condition An important point is that with this process in play, escape behavior (selfinjury) becomes more likely One could plausibly extend this model to other sources of motivation besides escape Thus, a person who is ill and in pain may, given an appropriate learning history, exhibit self-injury in the presence of a trigger stimulus to secure comfort, nurturance, and support (attention-seeking pattern) o r specific foods, toys, or activities (tangible-seeking pattern) The model we have just described is a plausible one that has been discussed in the literature However, because of the paucity of research in this area, it is fair to say that, in large measure, setting events is a descriptive rather than an explanatory term Thus, the lawful behavior changes that occur in response to the manipulation of setting events not in themselves explain the observed correlations or identift the responsible processes Nonetheless, it is the observed lawfulness of such behavior change that justifies making the exploration of setting events a research imperative for the future Because the proposed model links self-injurious behavior to specific consequences (escape, attention, and tangibles), it is an example of operant conditioning [Skinner, 19381-that is, the control of behavior by its consequences There is an important alternative to this operant setting event model Specifically, behavior can also be controlled by its antecedents in a reflexive paradigm [Pavlov, 19271 In this case, the painful stimulus functions as an unconditional stimulus that elicits self-injurious behavior irrespective ofwhether, for example, a demand is present or absent Thus, the pain associated with otitis media or constipation could set off a bout of self-injury even in the absence of demands A biological reflexive model is especially plausible in light of animal experiments showing that the delivery of a painful stimulus (electric shock) can elicit episodes of self-injury in monkeys [Frank et al., 1977; Gluck et al., 19851 It is likely that self-injurious behavior is influenced by both operant and reflexive biologcal factors It is useful, therefore, to consider how the relative contribution of each could be assessed empirically ASSESSMENT STRATEGY W e can illustrate one approach to the assessment issues just described by referring to our ongoing work on menstrual discomfort as a biological setting event for self-injurious behavior [Carr et al., 19931 W e have worked with several young women living in community residences whom staff members described as exhibiting greatly increased levels of self-injury during or just prior to their menses Staff descriptions clearly noted that the women showed many verbal and nonverbal manifestations of pain and discomfort at this time Further, it appeared that it was the combination of menstrual pain and the demands of daily living that exacerbated the problem behavior To test this notion, we pre- pain alone, even in the absence of trigger stimuli (the second assessment condition), should have generated self-injury, but it did not Second, it is likely that an operant setting-event model was operating because self-injury occurred almost exclusively as a joint function of the presence of both the trigger stimuli and the biologcal setting event (the fourth condition); this is the model outlined in Fig Trigger stimuli alone (the third condition), menses alone (the second condition), and, of course, the absence of both factors (the first condition) all failed to produce significant levels of selfinjury Thus, this assessment format can be useful in disentangling the role of reflexive and operant factors, thereby permitting identification of true setting events The likelihood that INTERVENTION IMPLICATIONS The likelihood that successful intervention will be multicomponent in nature is the most important implication of a setting-event model That is, some aspects of the intervention will need to target the biological component (e.g., menses) and some aspects will need to target the environmental component (e.g., demands) Again, we can illustrate these points with reference to our study of menses W e constructed multicomponent interventions that addressed the pain and discomfort associated with menses For one woman, for example, we included the following intervention components: use of a hot water bottle to alleviate cramping; restructuring her diet to avoid acidic foods that exacerbated stomach upset during menses; responding to her request for panty liners rather than pads because she found the latter more uncomfortable; providing comforting hugs, pats, and the like by female staff during periods of increased discomfort W e also included intervention components to address issues related to the trigger stimuli (demands): temporarily reducing demands during periods of intense discomfort; shifting the demands to times of day when the woman was feeling better; teaching her to request assistance from staff in carrying out demands when she was feeling badly; implementing positive mood induction techniques as a way of reducing the aversiveness of the demands The combination of biological and environmental elements into a multicomponent intervention package is a logical byproduct of a model that stresses the dual control of self-injurious behavior by environmental trigger stimuh and biologi- successful intervention will be multicomponent in nature is the most important implication of a setting-event model That is, some aspects of the intervention will need to target the biological component (e g ,menses) and some aspects will need to target the environmental component (e.g., demands) zyxw zyxw zyxw sented various combinations of trigger stimuli-eg., demands involving food preparation, grooming, cleaning one’s room, and the like-in the presence or absence of the biological setting event (i.e., obvious discomfort or pain associated with menses) The assessment consisted of four conditions: trigger stimulus absent and setting event absent; trigger stimulus absent and setting event present; trigger stimulus present and setting event absent; trigger stimulus present and setting event present Self-injury was negligible during the first three conditions and severe during the final condition This method of assessment is useful in addressing several issues raised earlier First, reflexive factors were not a major influence If they had been, menstrual zyxwvutsrq zyxwvutsrq MRDD RESFARCH REVIEWS BIOLOGICALSETTINGEVENTS CARR& SMITH zyxwvu 97 cal setting events Because of the complexities involved in such dual control, increased collaboration between medical practitioners and psychologists or educators in designing intervention is another logical consequence of the model we have presented H teaching behavior of adults J Appl Behav Analysis 24523-535 deLissovoy V (1961): Head banging in early childhood J Pediatr 58:803-805 deLissovoy V (1962): Head banging in early childhood Child Dev 33:43-56 deLissovoy V (1963): Head banging in early childhood: A suggested cause J Genet Psychol 102:109-1 14 deLissovoy V (1964): Head bangmg in early childhood: Review of empirical studies Pediatr Digest 649-55 Dennerstein L, Judd F, Davies B (1983): Psychosis and the menstrual cycle Med J Aust 1524526 Derby KM, Wacker DP, Sasso G, et al (1992): Brief functional assessment techniques to evaluate aberrant behavior in an outpatient setting: A summary of 79 cases J Appl Behav Analysis 25:713-721 Endicott J, Halbreich U, Schacht S, et al (1981): Premenstrual changes and affective disorders Psychosomat Med 43:519-529 Favell JE, McGimsey JF, Schell R M (1982): Treatment of self-injury by providing alternate sensory activities Analysis Intervention Dev Disabilities 2:83-104 Felthous AR, Robinson DB, Conroy R W (1980): Prevention of recurrent menstrual psychosis by an oral contraceptive Am J Psychiatry 137:245-246 Field C R (1981): Ecological illness: A factor in your caseload and perhaps in your life J Rehabil 47:15-18 Frank R G , Gluck JP, Strongin TS (1977): Response suppression to a shock-predicting stimulus in differentially reared monkeys (Macaca mulafa) Dev Psychol 13:295-296 Gardner JM (1985): Using microcomputers to help staff reduce violent behavior Comput Hum Serv 1:53-61 Gardner WI, Cole CL, Davidson DP et al (1986): Reducing aggression in individuals with developmental disabilities:An expanded stimulus control, assessment, and intervention model Educ Training Ment Retard 21:3-12 Gardner WI, Sovner R (1994): Self-Injurious Behaviors Willow Street, P A Vida Publishing Ghaziuddin M, Elkins TE, McNeeley SG, et al (1993): Premenstrual syndrome in women with mental handicap: A pilot study Br J Dev Disabil39:104-107 Gluck JP, Otto MW, Beauchamp AJ (1985): Respondent conditioning of self-injurious behavior in early socially deprived rhesus monkeys J Abnorm Psychol 94:222-226 Gourash LF (1986): Assessing and managing medical factors In Barrett R P (ed): Severe Behavior Disorders in the Mentally Retarded New York: Plenum, pp 157-205 Gunsett R P , Mulick JA, Fernald WB et al (1989): Brief report: Indications for medical screening prior to behavioral programming for severely and profoundly mentally retarded clients J Autism Dev Disord 19:167-172 Iwata BA, Dorsey MF, Slifer KJ, et al (1982): Toward a functional analysis of self-injury Analysis Intervention Dev Disabil2:3-20 Iwata BA, Pace GM, Kalsher MJ, et al (1990): Experimental analysis and extinction of selfinjurious escape behavior J Appl Behav Analysis 23:ll-27 Kennedy CH, Itkonen T (1993): Effects of setting events on the problem behavior of students with severe disabilities J Appl Behav Analysis 26:321-327 Lekkas C N , Lentino W (1978): Symptomproducing interposition of the colon: Clinical syndrome in mentally deficient adults J Am Med Assoc 240:747-750 Lovaas 01, Freitag G, Gold VJ, et al (1965): Experimental studies in childhood schizophrenia: Analysis of self-destructive behavior J EXPChild Psycho1 2~67-84 Michael J (1982): Distinguishing between discriminative and motivational functions of stimuli J Exp Analysis Behav 37:149-155 O’Neill RE, Horner R H , Albin R W , et al (1990): Functional Analysis of Problem Behavior: A Practical Assessment Guide Sycamore, IL: Sycamore Press Pavlov IP (1927): Conditioned Reflexes New York: Dover Publications Rincover A, Devaney J (1982): The application of sensory extinction procedures to self-injury Analysis Intervention Dev Disabil2:67-81 Roy A, Simon GB (1987): Intestinal obstruction as a cause ofdeath in the mentally handicapped.J Ment Defic Res 31:193-197 Skinner BF (1938): The Behavior of Organisms New York Appleton-Century-Crofts Taylor JC, Carr EG (1992): Severe problem behaviors related to social interaction I: Attention seeking and social avoidance Behav Modif 16:30S-335 Taylor DV, Rush D, Hetrick WP, et al (1993): Self-injurious behavior within the menstrual cycle ofwomen with mental retardation Am J Ment Retard 97559-664 zyxwvutsrq zyxwvutsr ACKNOWLEDGMENT Preparation of this manuscript was supported in part by Grant H133G20098 and Cooperative Agreement H133B20004 from the U.S Department of Education We thank Dr Martin Hamburg, Executive Director, Developmental Disabilities Institute, for his generous support References Altschule MD, Brem J (1963): Periodic psychosis of puberty AmJ Psychiatry 119:1176-1178 Bailey JS, Pyles DAM (1989): Behavioral diagnostics In Cipani E (ed), The treatment of severe behavior disorders, Monographs ofthe Amencan Association on Mental Retardation, 12 Bijou SW, Baer DM (1961): Child Development I: A Systematic and Empirical Theory Englewood Cliffs, NJ: Prentice-Hall Carr EG, Durand VM (1985): Reducing behavior problems through functional communication training J Appl Behav Analysis 18:111-126 Carr EG, McDowell JJ (1980): Social control of self-injurious behavior of organic etiology Behav Ther 11:402-409 Carr EG, Newsom CD, Binkoff JA (1976): Stimulus control of self-destructive behavior in a psychotic child J Abnorm Child Psychol 4:139-153 Carr EG, Robinson S, TaylorJC, CarlsonJI (1990): Positive approaches to the treatment of severe behavior problems in persons with developmental disabilities: A review and analysis of reinforcement and stimulus-based procedures Monograph of The Association for Persons with Severe Handicaps Carr EG, Smith CE, Magito-McLaughlin D, Reeve CE (1993, May): Mood, menses, and meaning: Complex determinants ofproblem behavior Paper presented at the annual meeting of the Association for Behavior Analysis, Chicago Carr EG, TaylorJC, Robinson S (1991): The effects ofsevere behavior problems in children on the 98 zyxwvuts MRDD RESEARCH REVIEWS BIOLOGICALSETTINGEVENTS zy CARR& SMITH ... framework for understanding the effects of biological setting events on self-injurious behavior Problem behavior is influenced by context (setting events and trigger stimuli) Setting events alter... we propose a model for exploring the relationship between self-injury and b i o l o g d setting events MRDD RESEARCH REVIEWSBIOLOGICALSETTINGEVENTS zy CARR& SMITH various biological factors we... argument that biological setting events are pervasive and therefore worth looking at more systematically than has been done to date Fatigue has been suggested as a possible setting event for self-injury