Importance of Reward and Prefrontal Circuitry in Hunger and Satiety: Prader-Willi Syndrome vs. Simple Obesity

Background: The majority of research on obesity 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 which are associated with appetite-regulatory hormones are also involved in the development and maintenance of obesity. 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 obesity. Simple (non-PWS) obesity (OB) represents an obesity 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 (i.e., hypothalamus, amygdala) and prefrontal regions associated with cognitive control [i.e., dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC)] after eating. Design and Participants: Fourteen individuals with PWS, 14 BMI- and age-matched individuals with OB, and 15 age-matched healthy-weight controls (HWC) 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 hypothalamus and hippocampus, in response to food (vs. non-food) images pre-meal. Post-meal, PWS exhibited higher subcortical activation (hypothalamus, amygdala, hippocampus) compared to 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 obesity 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 obesity

Response to ABAI task force on the use of contingent electric skin shock

In this article, the authors provide their response to the Association for Behavior Analysis International (2022) position statement on the use of contingent electric skin shock (CESS). In this response, we address concerns raised by the task force regarding limitations of the Zarcone et al. (2020) review article in which both methodological and ethical concerns were raised about the quality of research in the use of CESS with people with disabilities in the treatment of challenging behavior. We note that with the exception of the Judge Rotenberg Center in Massachusetts, no state or country currently supports the use of CESS as it is not recognized as the standard of care in any other program, school, or facility

MOMENTUM VERSUS EXTINCTION EFFECTS IN THE TREATMENT OF SELF-INJURIOUS ESCAPE BEHAVIOR

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

TEACHING WOMEN WITH INTELLECTUAL DISABILITIES TO IDENTIFY AND REPORT INAPPROPRIATE STAFF-TO-RESIDENT INTERACTIONS

This study examined the effectiveness of behavioral skills training in teaching 2 adult women with mild intellectual disabilities to report inappropriate staff-to-resident interactions. The reporting skill included making a self-advocacy response, walking away, and reporting the interaction. Participants' performance was measured during baseline, posttesting, 2- and 4-week follow-up, and generalization probes in new situations. All participants learned reporting skills, maintained these skills at 2- and 4-week follow-up, and generalized the skills to novel stimulus situations

Reemergence and extinction of self-injurious escape behavior during stimulus (instructional) fading.

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

PARAMETRIC ANALYSIS OF PRESESSION EXPOSURE TO EDIBLE AND NONEDIBLE STIMULI

We assessed the effects of individually defined small, medium, and large periods of presession access to edible and nonedible reinforcers on response rates during sessions in which responding produced access to identical reinforcers. Any presession access to an edible reinforcer decreased response rates for 1 participant, and small and medium periods of presession access to nonedible reinforcers resulted in similar or increased response rates for 2 participants

Pyramidal staff training in the extension of treatment for severe behavior disorders.

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

ADouble-Blind, Placebo-Controlled Study of Valproate for Aggression in Youth with Pervasive Developmental Disorders

Objective: The aim of this study was to study valproate efficacy and safety for aggression in children and adolescents with pervasive developmental disorders (PDD). Methods: In this prospective double-blind, placebo-controlled study, 30 subjects (20 boys, 10 girls) 6–20 years of age with PDD and significant aggression were randomized and received treatment with valproate (VPA) or placebo (PBO) for 8 weeks as outpatients. Mean VPA trough blood levels were 75.5 mcg/mL at week 4 and 77.8 mcg/mL at week 8. Results: No treatment difference was observed statistically between VPA and PBO groups. The Aberrant Behavior Checklist—Community Scale (ABC-C) Irritability subscale was the primary outcome measure (p = 0.65), and CGI—Improvement (p = 0.16) and OAS (p = 0.96) were secondary outcome measures. Increased appetite and skin rash were significant side effects. Only 1 subject was dropped from the study owing to side effects, notably a spreading skin rash, which then resolved spontaneously. Two subjects receiving VPA developed increased serum ammonia levels, one with an associated parent report of slurred speech and mild cognitive slowing. Poststudy, of 16 VPA and PBO subjects receiving VPA, 10 subjects demonstrated sustained response, 4 of whom later attempted taper, with significant relapse of aggression. Conclusion: The present negative findings cannot be viewed as conclusive, partly owing to the large placebo response, subject heterogeneity, and size of the groups. Larger studies are needed to expand upon these findings.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63307/1/cap.2005.15.682.pd