RESUMEN
BACKGROUND: The majority of research on obesity (OB) has focused primarily on clinical features (eating behavior, adiposity measures) or peripheral appetite-regulatory peptides (leptin, ghrelin). However, recent functional neuroimaging studies have demonstrated that some reward circuitry regions that are associated with appetite-regulatory hormones are also involved in the development and maintenance of OB. Prader-Willi syndrome (PWS), characterized by hyperphagia and hyperghrelinemia reflecting multi-system dysfunction in inhibitory and satiety mechanisms, serves as an extreme model of genetic OB. Simple (non-PWS) OB represents an OB-control state. OBJECTIVE: This study investigated subcortical food motivation circuitry and prefrontal inhibitory circuitry functioning in response to food stimuli before and after eating in individuals with PWS compared with OB. We hypothesized that groups would differ in limbic regions (that is, hypothalamus, amygdala) and prefrontal regions associated with cognitive control (that is, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC) after eating. DESIGN AND PARTICIPANTS: A total of 14 individuals with PWS, 14 BMI- and age-matched individuals with OB, and 15 age-matched healthy-weight controls viewed food and non-food images while undergoing functional MRI before (pre-meal) and after (post-meal) eating. Using SPM8, group contrasts were tested for hypothesized regions: hypothalamus, nucleus accumbens (NAc), amygdala, hippocampus, OFC, medial PFC and DLPFC. RESULTS: Compared with OB and HWC, PWS demonstrated higher activity in reward/limbic regions (NAc, amygdala) and lower activity in the hypothalamus and hippocampus in response to food (vs non-food) images pre-meal. Post meal, PWS exhibited higher subcortical activation (hypothalamus, amygdala, hippocampus) compared with OB and HWC. OB showed significantly higher activity versus PWS and HWC in cortical regions (DLPFC, OFC) associated with inhibitory control. CONCLUSION: In PWS, compared with OB per se, results suggest hyperactivations in subcortical reward circuitry and hypoactivations in cortical inhibitory regions after eating, which provides evidence of neural substrates associated with variable abnormal food motivation phenotypes in PWS and simple OB.
Asunto(s)
Neuroimagen Funcional/métodos , Hambre , Obesidad/fisiopatología , Síndrome de Prader-Willi/fisiopatología , Corteza Prefrontal/fisiopatología , Saciedad , Adulto , Mapeo Encefálico , Conducta Alimentaria/psicología , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Obesidad/psicología , Estimulación Luminosa , Periodo Posprandial , Síndrome de Prader-Willi/psicología , Recompensa , Encuestas y CuestionariosRESUMEN
OBJECTIVE: To investigate the neural mechanisms of food motivation in children and adolescents, and examine brain activation differences between healthy weight (HW) and obese participants. SUBJECTS: Ten HW children (ages 11-16; BMI < 85%ile) and 10 obese children (ages 10-17; BMI >95%ile) matched for age, gender and years of education. MEASUREMENTS: Functional magnetic resonance imaging (fMRI) scans were conducted twice: when participants were hungry (pre-meal) and immediately after a standardized meal (post-meal). During the fMRI scans, the participants passively viewed blocked images of food, non-food (animals) and blurred baseline control. RESULTS: Both groups of children showed brain activation to food images in the limbic and paralimbic regions (PFC/OFC). The obese group showed significantly greater activation to food pictures in the PFC (pre-meal) and OFC (post-meal) than the HW group. In addition, the obese group showed less post-meal reduction of activation (vs pre-meal) in the PFC, limbic and the reward-processing regions, including the nucleus accumbens. CONCLUSION: Limbic and paralimbic activation in high food motivation states was noted in both groups of participants. However, obese children were hyper-responsive to food stimuli as compared with HW children. In addition, unlike HW children, brain activations in response to food stimuli in obese children failed to diminish significantly after eating. This study provides initial evidence that obesity, even among children, is associated with abnormalities in neural networks involved in food motivation, and that the origins of neural circuitry dysfunction associated with obesity may begin early in life.
Asunto(s)
Hambre/fisiología , Sistema Límbico/fisiopatología , Motivación/fisiología , Obesidad/fisiopatología , Adolescente , Niño , Conducta Alimentaria/fisiología , Conducta Alimentaria/psicología , Femenino , Alimentos , Humanos , Imagen por Resonancia Magnética , Masculino , Obesidad/psicología , Estimulación Luminosa/métodos , Periodo PosprandialRESUMEN
BACKGROUND: Differences in behavioral phenotypes between the two most common subtypes of Prader-Willi syndrome (PWS) (chromosome 15q deletions and maternal uniparental disomy 15 (UPD) indicate that distinct neural networks may be affected. Though both subtypes display hyperphagia, the deletion subgroup shows reduced behavioral inhibition around food, whereas those with UPD are generally more able to maintain cognitive control over food intake impulses. OBJECTIVE: To examine the neural basis of phenotypic differences to better understand relationships between genetic subtypes and behavioral outcomes. We predicted greater food motivation circuitry activity in the deletion subtype and greater activity in higher order cognitive regions in the UPD group, especially after eating. DESIGN AND PARTICIPANTS: Nine individuals with PWS due to UPD and nine individuals with PWS due to (type 2) deletion, matched for age, gender and body mass index, underwent functional magnetic resonance imaging (fMRI) while viewing food images during two food motivation states: one before (pre-meal) and one after (post-meal) eating a standardized 500 kcal meal. RESULTS: Both PWS subgroups showed greater activity in response to food pre- and post-meal compared with the healthy-weight group. Compared with UPD, the deletion subtype showed increased food motivation network activation both pre- and post-meal, especially in the medial prefrontal cortex (mPFC) and amygdala. In contrast, the UPD group showed greater activation than the deletion subtype post-meal in the dorsolateral prefrontal cortex (DLPFC) and parahippocampal gyrus (PHG). CONCLUSION: These preliminary findings are the first functional neuroimaging findings to support divergent neural mechanisms associated with behavioral phenotypes in genetic subtypes of PWS. Results are discussed within the framework of genetic mechanisms such as haploinsufficiency and gene dosage effects and their differential influence on deletion and UPD subtypes, respectively.
Asunto(s)
Apetito/fisiología , Encéfalo/fisiopatología , Hiperfagia/fisiopatología , Síndrome de Prader-Willi/fisiopatología , Apetito/genética , Deleción Cromosómica , Cromosomas Humanos Par 15/genética , Femenino , Humanos , Hiperfagia/genética , Hiperfagia/psicología , Imagen por Resonancia Magnética , Masculino , Red Nerviosa , Fenotipo , Estimulación Luminosa , Síndrome de Prader-Willi/genética , Síndrome de Prader-Willi/psicología , Encuestas y Cuestionarios , Disomía Uniparental/genética , Adulto JovenRESUMEN
BACKGROUND: Within the scope of a double-blind, placebo-controlled, crossover medication study, the Diagnostic Assessment of the Severely Handicapped-II (DASH-II) was evaluated as a measurement for determining the effectiveness of the medication risperidone in treating the problem behaviour of 21 people with intellectual disabilities (ID). METHOD: Participants' caregivers completed the DASH-II during the placebo/baseline phase of the study and the maintenance phase of the study, and completed the Aberrant Behavior Checklist - Community (ABC-C) weekly throughout the entire study. The results obtained using the DASH-II were compared to those obtained using the ABC-C, an instrument shown to be well correlated with the DASH-II. RESULTS: Results suggest that while the DASH-II and the ABC-C were well correlated during the placebo/baseline phase of the current study, they were not well correlated at completion of the 6-month maintenance phase of the medication trial. CONCLUSION: The DASH-II, while appropriate for assisting in the diagnosis of psychopathology in people with ID, does not appear to monitor changes in problem behaviour as a result of risperidone use as well as the ABC-C. Differences in the frequency of problem behaviour that each measure evaluated and the applicability of using the DASH-II to measure medication effects on problem behaviour are discussed.
Asunto(s)
Antipsicóticos/uso terapéutico , Personas con Discapacidad , Trastornos Mentales/diagnóstico , Trastornos Mentales/tratamiento farmacológico , Risperidona/uso terapéutico , Encuestas y Cuestionarios , Estudios Cruzados , Método Doble Ciego , Humanos , Trastornos Mentales/clasificación , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
The efficacy of the atypical antipsychotic risperidone was evaluated in the treatment of aberrant behavior (e.g., aggression, self-injury) in 20 individuals with developmental disabilities. A double-blind, crossover design was used to compare risperidone with placebo in a 22-week trial with a 6-month follow-up phase. Based on a 50% reduction in mean Aberrant Behavior Checklist--Community total scores, 50% of the participants were identified as responders. Naturalistic observations of a subset of five individuals showed that for 4 out of 5 participants, risperidone was effective in reducing aberrant behavior. Side effects included weight gain (84% of participants) and sedation (40% of participants). The advantages of conducting a comprehensive analysis of the effects of medication on aberrant behavior are discussed.
Asunto(s)
Agresión/efectos de los fármacos , Discapacidad Intelectual/tratamiento farmacológico , Risperidona/uso terapéutico , Conducta Autodestructiva/tratamiento farmacológico , Adolescente , Adulto , Anciano , Niño , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/psicología , Masculino , Persona de Mediana Edad , Risperidona/efectos adversos , Conducta Autodestructiva/diagnóstico , Conducta Autodestructiva/psicología , Resultado del TratamientoRESUMEN
As part of an ongoing, prospective, ABA design, double-blind crossover study of risperidone versus placebo for the treatment of aggressive, destructive and self-injurious behavior in persons aged 6-65 years with mental retardation (MR) and autism, we measured the weight of 19 subjects at each study visit. We compared mean weight gain during the 16-week acute phase and 24-week open maintenance phase with that during the initial and middle placebo phases statistically, using a linear mixed model procedure. Results of the linear mixed model analysis showed that relative weight gain observed during the acute and maintenance drug phases was significantly greater than that observed during the initial and middle placebo phases respectively (p = .0001 and p = .0001). Over approximately a year, children aged 8-12 (n = 5) gained a mean of 8.2 kg (range = 2.7-17.7 kg); adolescents (n = 6) aged 13-16 gained a mean of 8.4 kg (range 3.6-15.5 kg); adults aged 21-51 (n = 8) gained a mean of 5.4 kg (range 0-9.5 kg). Weight gain observed in this controlled study of risperidone treatment in children, adolescents, and adults with MR and autism was significant. It may be greater in this population than in others reported and in this study was not limited to an acute effect only. Rate of weight gain diminished rapidly on tapering and stopping the drug. Further studies are urgently needed, including those incorporating diet and exercise programming.
Asunto(s)
Antipsicóticos/efectos adversos , Trastorno Autístico/tratamiento farmacológico , Discapacidad Intelectual/tratamiento farmacológico , Risperidona/efectos adversos , Aumento de Peso/efectos de los fármacos , Adolescente , Adulto , Anciano , Agresión/efectos de los fármacos , Antipsicóticos/uso terapéutico , Trastorno Autístico/complicaciones , Niño , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Humanos , Discapacidad Intelectual/complicaciones , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Risperidona/uso terapéutico , Conducta Autodestructiva/tratamiento farmacológico , Conducta Autodestructiva/etiologíaRESUMEN
A brief negative-reinforcement assessment was conducted with developmentally disabled children with severe destructive behavior. Five children were trained to engage in a simple escape response (e.g., a hand clap). Then each child was presented with a variety of stimuli or tasks that ranged on a scale from preferred to nonpreferred, based on parent ranking. The participant received a brief break from the stimuli or task, contingent on each escape response. For one child, an avoidance contingency was also implemented in which he could engage in the response to avoid the presentation of stimuli. Results showed that for each child, several stimuli were identified that may serve as effective negative reinforcers. Results also indicated that the procedure did not elicit any negative side effects for four children and low rates of destructive behavior for the fifth child. For one child, the results of the negative-reinforcement assessment were used to develop an effective treatment for destructive behavior. Additional applications of the reinforcement assessment to treatment interventions is discussed, as well as limitations to the procedure.
Asunto(s)
Terapia Conductista/métodos , Trastornos de la Conducta Infantil/terapia , Discapacidad Intelectual/terapia , Refuerzo en Psicología , Adolescente , Agresión/psicología , Déficit de la Atención y Trastornos de Conducta Disruptiva/psicología , Déficit de la Atención y Trastornos de Conducta Disruptiva/terapia , Niño , Trastornos de la Conducta Infantil/psicología , Preescolar , Educación de las Personas con Discapacidad Intelectual , Femenino , Humanos , Discapacidad Intelectual/psicología , Masculino , Conducta Autodestructiva/prevención & control , Conducta Autodestructiva/psicología , Resultado del TratamientoRESUMEN
We used descriptive assessment information to generate hypotheses regarding the function of destructive behavior for 2 individuals who displayed near-zero rates of problem behavior during an experimental functional analysis using methods similar to Iwata, Dorsey, Slifer, Bauman, and Richman (1982/1994). The descriptive data suggested that destructive behavior occurred primarily when caregivers issued requests to the participants that interfered with ongoing high-probability (and presumably highly preferred) behaviors (i.e., a "don't" or a symmetrical "do" request). Subsequent experimental analyses showed that destructive behavior was maintained by contingent termination of "don't" and symmetrical "do" requests but not by termination of topographically similar "do" requests. These results suggested that destructive behavior may have been maintained by positive reinforcement (i.e., termination of the "don't" request allowed the individual to return to a highly preferred activity). Finally, a treatment (functional communication training plus extinction) developed on the basis of these analyses reduced destructive behavior to near-zero levels.
Asunto(s)
Agresión/psicología , Trastorno por Déficit de Atención con Hiperactividad/rehabilitación , Terapia Conductista/métodos , Trastorno Bipolar/rehabilitación , Refuerzo en Psicología , Adolescente , Agresión/clasificación , Trastorno por Déficit de Atención con Hiperactividad/complicaciones , Trastorno Bipolar/complicaciones , Cuidadores/educación , Comunicación , Discapacidades del Desarrollo/complicaciones , Extinción Psicológica , Femenino , Humanos , Discapacidad Intelectual/complicaciones , Masculino , Estadística como AsuntoRESUMEN
Providing a short break contingent on completed work may increase responding through positive reinforcement (e.g., access to preferred activities) or negative reinforcement (e.g., escape form work). In this investigation, three analyses conducted with a boy with profound mental retardation showed that (a) a 20-s break increased responding more than a positive reinforcer (cola) did, and (b) the reinforcing effect of a 20-s break were affected by the availability of positive reinforcers during the break were affected by the availability of positive reinforcers during the break.
Asunto(s)
Trastorno Autístico/terapia , Educación de las Personas con Discapacidad Intelectual , Discapacidad Intelectual/terapia , Actividades Recreativas , Motivación , Refuerzo en Psicología , Trastorno Autístico/psicología , Niño , Conducta Cooperativa , Aprendizaje Discriminativo , Humanos , Discapacidad Intelectual/psicología , Masculino , Desempeño Psicomotor , Régimen de RecompensaRESUMEN
We implemented a pyramidal training procedure for staff working with individuals who exhibited self-injurious behavior (SIB), aggression, and disruption. Two adults with developmental disabilities and their direct-care staff and supervisors participated. Following successful treatment by the experimenters, two types of baselines were conducted with the clients and their direct-care staff. During an initial baseline, the staff implemented preexisting procedures. Staff members then received instruction on the new treatment procedures using training methods common throughout the institution, and data were collected during this "post-in-service" baseline. Experimenters then taught unit supervisors to implement treatment, collect and interpret data, and provide similar instructions and feedback to the staff members. The supervisor training was implemented in a multiple baseline design across subjects (clients and direct-care staff). Results showed little change following in-service training but noticeable improvements in direct-care staff behaviors and corresponding decreases in the clients' inappropriate behavior following the pyramidal training intervention with supervisors. Six additional clients (along with their direct-care staff and supervisors) participated in pre- and posttreatment replication designs, and their results provided additional support for the efficacy of the supervisor training procedures.
Asunto(s)
Agresión/psicología , Terapia Conductista/métodos , Capacitación en Servicio , Discapacidad Intelectual/terapia , Grupo de Atención al Paciente , Conducta Autodestructiva/terapia , Actividades Cotidianas/psicología , Adulto , Centros de Día , Retroalimentación , Femenino , Estudios de Seguimiento , Humanos , Discapacidad Intelectual/psicología , Masculino , Instituciones Residenciales , Conducta Autodestructiva/psicología , Conducta Social , Régimen de RecompensaRESUMEN
Multielement and reversal designs used to identify maintaining variables for behavior disorders such as self-injury have several potential limitations, including interaction effects (multielement), inefficiency (reversal), and lack of a continuous control (reversal). This article describes a methodology that minimizes these problems yet captures the best features of both designs. This design consists of several phases implemented in a sequential (A-B-C) fashion, as in the reversal design. However, each phase consists of two conditions, a test and a control, presented concurrently in a multielement format. Five subjects' self-injury was assessed using both the multielement design and the sequential, test-control (or pairwise) design. Results for two subjects indicated that the multielement design produced clear assessment outcomes, and similar findings were obtained using the pairwise design. For two other subjects, the multielement assessments were somewhat undifferentiated, and clearer results were obtained using the pairwise design. The fifth subject's self-injury showed cyclical patterns using both assessment techniques. Benefits and limitations of the sequential assessment methodology are discussed.
Asunto(s)
Conducta Autodestructiva/diagnóstico , Adulto , Terapia Conductista , Femenino , Humanos , Masculino , Conducta Autodestructiva/terapiaRESUMEN
Data are summarized from 152 single-subject analyses of the reinforcing functions of self-injurious behavior (SIB). Individuals with developmental disabilities referred for assessment and/or treatment over an 11-year period were exposed to a series of conditions in which the effects of antecedent and consequent events on SIB were examined systematically by way of multielement, reversal, or combined designs. Data were collected during approximately 4,000 experimental sessions (1,000 hr), with the length of assessment for individuals ranging from 8 to 66 sessions (M = 26.2) conducted over 2 to 16.5 hr (M = 6.5). Differential or uniformly high responding was observed in 145 (95.4%) of the cases. Social-negative reinforcement (escape from task demands or other sources of aversive stimulation) accounted for 58 cases, which was the largest proportion of the sample (38.1%). Social-positive reinforcement (either attention or access to food or materials) accounted for 40 (26.3%) of the cases, automatic (sensory) reinforcement accounted for 39 (25.7%), and multiple controlling variables accounted for 8 (5.3%). Seven sets of data (4.6%) showed either cyclical or inconsistent patterns of responding that were uninterpretable. Overall results indicated that functional analysis methodologies are extremely effective in identifying the environmental determinants of SIB on an individual basis and, subsequently, in guiding the process of treatment selection. Furthermore, an accumulation of assessment data from such analyses across a large number of individuals provides perhaps the most rigorous approach to an epidemiological study of behavioral function.
Asunto(s)
Conducta Autodestructiva/epidemiología , Adolescente , Adulto , Anciano , Atención , Niño , Preescolar , Extinción Psicológica , Femenino , Humanos , Lactante , Discapacidad Intelectual/complicaciones , Masculino , Persona de Mediana Edad , Refuerzo en Psicología , Reproducibilidad de los Resultados , Conducta Autodestructiva/complicaciones , Conducta Autodestructiva/diagnósticoRESUMEN
Based on results of a functional analysis indicating that the self-injurious behavior (SIB) of 3 individuals was maintained by negative reinforcement (escape from instructional situations), the effects of stimulus (instructional) fading were evaluated in a multiple baseline design across subjects. The rate of instructions was reduced to zero at the beginning of treatment and was gradually increased (faded in) across sessions as long as SIB remained low. However, if SIB remained high for 10 consecutive sessions, extinction was implemented until SIB decreased, at which point extinction was withdrawn and fading was resumed. Treatment was completed when the rate of instructions was the same as in baseline (two per minute), and SIB remained below 0.5 responses per minute for two consecutive sessions. Results showed that instructional fading (without extinction) virtually eliminated SIB initially, but these effects were not maintained. All 3 subjects required multiple exposures to extinction and over 150 treatment sessions in order to meet the end-of-treatment criteria. Advantages and limitations of fading procedures without an extinction component, as well as extensions of both interventions to other clinical problems, are discussed.
Asunto(s)
Extinción Psicológica , Conducta Autodestructiva/terapia , Adulto , Terapia Conductista , Femenino , Humanos , Discapacidad Intelectual/complicaciones , Discapacidad Intelectual/psicología , Masculino , Conducta Autodestructiva/complicacionesRESUMEN
We examined the effects of noncontingent and contingent protective equipment as treatment for self-injurious hand mouthing exhibited by 2 individuals with profound mental retardation. Results of a functional analysis assessment revealed that neither subject's self-injury was maintained by social reinforcement: One subject's self-injury was cyclical in nature; the other's occurred during all assessment conditions but most frequently when left alone. In the noncontingent-equipment condition, oven mitts were placed on the individual's hands at the beginning of a session and remained on throughout. In the contingent-equipment condition, the mitts were briefly placed on the individual's hands following occurrences of hand mouthing. For 1 subject, noncontingent mitts produced a large decrease in the rate of hand mouthing and contingent mitts produced similar results following a return to baseline. Hand mouthing was also reduced in the 2nd subject, but this individual was exposed only to the contingent-equipment condition (i.e., there was no prior history with the noncontingent-equipment condition). These results suggest either a punishment or a time-out interpretation rather than an extinction interpretation to account for the behavior-reducing effects of contingent protective equipment on self-injury.
Asunto(s)
Equipos de Seguridad/estadística & datos numéricos , Conducta Autodestructiva/terapia , Adulto , Extinción Psicológica , Femenino , Humanos , Discapacidad Intelectual/complicaciones , Refuerzo en Psicología , Reproducibilidad de los Resultados , Proyectos de Investigación , Conducta Autodestructiva/complicaciones , Conducta EstereotipadaRESUMEN
When relapse occurs following successful treatment to reduce problem behavior, it is often attributed to inconsistent implementation of maintenance programs. Although less likely, another potential cause for relapse is a change in the behavior's maintaining contingency over time. To examine this possibility, additional assessment was conducted with 4 individuals who were rereferred to a day-treatment program due to recurrence of their self-injurious behavior (SIB) 2 months to 2 years following successful treatment. In each case, the original treatment had been developed and implemented based on the outcome of functional analysis assessments. For 1 subject, results of a second functional analysis were consistent with those from the original assessment, indicating that the function of her SIB had remained unchanged. For the other 3 subjects, results of the second assessment suggested that their SIB had acquired new or additional functions. These findings indicate that factors other than program inconsistency can lead to relapse, and that clinical reevaluation for such cases should include a current functional analysis to determine if new treatment components are needed.
Asunto(s)
Conducta Autodestructiva/terapia , Adulto , Terapia Conductista , Extinción Psicológica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia , Refuerzo en Psicología , Proyectos de Investigación , Conducta Autodestructiva/diagnósticoRESUMEN
Previous research on applications of behavioral momentum has indicated that a high-probability (high-p) instructional sequence, in which a series of instructions for which there is a high probability of compliance is presented immediately before an instruction for which there is a low probability of compliance, is an effective method for increasing compliance. It is not clear, however, whether the procedure is effective when individuals actively attempt to escape from the instructional situation. In this study, we examined the effects of the high-p sequence, when implemented first alone and then later with an extinction component, as treatment for the self-injurious escape behavior of 2 individuals. Results showed that when the instructional sequence was implemented without extinction, rates of self-injury increased and percentage of compliance decreased. In addition, the percentage of trials occasioning escape behavior increased for both high- and low-probability instructions. When an extinction component was added to the high-p sequence, rates of self-injury and the percentage of trials containing self-injury decreased, and compliance increased. These findings suggest that extinction may be an important component of treatment when escape behavior such as self-injury accompanies noncompliance in instructional contexts and competes with compliant behavior.
Asunto(s)
Extinción Psicológica , Cooperación del Paciente , Conducta Autodestructiva/prevención & control , Adulto , Humanos , Masculino , Persona de Mediana Edad , Tiempo de ReacciónRESUMEN
Certain responses of both humans and nonhumans appear to be maintained indirectly by intermittent reinforcement schedules and have been referred to collectively as adjunctive behavior. Although basic research has examined adjunctive behavior extensively, relatively few studies have been conducted with humans, particularly those with developmental disabilities who often engage in frequent and varied stereotypic behavior. This study assessed possible adjunctive characteristics of self-injurious and stereotypic behaviors using a multielement design containing two types of control conditions. Four subjects who engaged in both self-injurious behavior and stereotypy participated after variables maintaining their self-injury were identified via functional analyses. Each day, subjects were exposed to three 15-min sessions in random order: (a) noncontingent presentation of food on a fixed-time schedule (e.g., FT 30 s), (b) a massed-reinforcement (food) control, and (c) a no-reinforcement control. A variety of fixed-time schedules were examined during different experimental phases. Results of this preliminary study suggested that self-injury was not induced by intermittent reinforcement schedules, whereas the stereotypic behavior of some individuals showed characteristics of adjunctive behavior. The importance of research on adjunctive behavior and suggestions for future studies are discussed.
Asunto(s)
Esquema de Refuerzo , Refuerzo en Psicología , Conducta Autodestructiva , Conducta Estereotipada , Adulto , Femenino , Humanos , Discapacidad Intelectual/complicaciones , Masculino , Tiempo de Reacción , Conducta Autodestructiva/complicacionesRESUMEN
Functional analysis assessment procedures have proven to be highly useful in identifying variables maintaining aberrant behavior like self-injury. When successful, assessments can lead to more effective treatment than when behavioral function is unknown. Because of practical limitations, not all clinicians can conduct extensive and thorough analyses prior to treatment implementation. Although relatively brief assessments have proven successful in a number of published studies, it is unclear under what conditions those assessments would match the results of a more extended analysis. This study examined a method for assessing the behavioral function of severe self-injury in four adult participants. For each participant, the initial assessment involved analyzing within-session trends and fluctuations in rates of self-injury by plotting the frequency within each minute of a session. The results of these analyses were then compared to a set of more traditional, longer-term functional analyses conducted with each participant. Results suggested that within-session analyses are viable procedures for the assessment of self-injury. Potential benefits of within-session analyses over other brief assessments and longer-term analyses are discussed.
Asunto(s)
Terapia Conductista , Condicionamiento Operante , Discapacidad Intelectual/psicología , Conducta Autodestructiva/psicología , Adulto , Atención , Educación de las Personas con Discapacidad Intelectual , Extinción Psicológica , Femenino , Humanos , Discapacidad Intelectual/terapia , Masculino , Juego e Implementos de Juego , Refuerzo Social , Conducta Autodestructiva/terapia , Medio SocialRESUMEN
Three individuals with developmental disabilities participated in a study of the treatment of self-injurious behavior (SIB) maintained by negative reinforcement (escape from educational tasks). Treatment was implemented in a multiple baseline design across subjects, in which two treatments were compared in a multielement format. Both treatment conditions included an escape-extinction component in which SIB no longer produced escape. One of the conditions also included a fading component in which the frequency of instructions was initially reduced to zero and then was gradually faded back in across sessions until the instructional rate matched that of the original baseline. Results indicated that extinction alone reduced SIB to the end-of-treatment criterion in fewer sessions than did extinction plus fading for all 3 subjects. For 2 of the 3 subjects, however, there was an initial increase in the frequency of SIB at the outset of treatment with extinction (an extinction burst) that was not observed when extinction was combined with the fading component.
Asunto(s)
Terapia Conductista/métodos , Síndrome de Down/terapia , Reacción de Fuga , Extinción Psicológica , Discapacidad Intelectual/terapia , Conducta Autodestructiva/terapia , Adulto , Atención , Síndrome de Down/psicología , Educación de las Personas con Discapacidad Intelectual , Femenino , Humanos , Discapacidad Intelectual/psicología , Refuerzo en Psicología , Conducta Autodestructiva/psicología , Resultado del TratamientoRESUMEN
An individual's self-injurious escape behavior was treated using a high-probability instructional sequence with and without extinction. When presented alone, the high-probability sequence did not reduce self-injurious behavior. When escape extinction was implemented either alone or in combination with the high-probability sequence, self-injury decreased and compliance increased, suggesting that extinction may be a necessary component of the treatment for behavior problems maintained by escape.