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This study examined the links among body mass index (BMI), weight control practices, binge eating, and eating disorders in 1164 middle school girls. Both the prevalence and frequency of weight control behaviors increased as BMI increased, but binge eating was reported approximately equally by girls across the BMI spectrum.
Behavior therapy of obesity is very widely used and is the subject of numerous reports in the medical literature. The background of this therapy is described and a table lists the 49 most commonly used elements of behavioral weight control as abstracted from five of the most widely read publications on the topic.
OBJECTIVE: To assess the impact of an obesity prevention intervention on use of self-induced vomiting/laxatives (purging) and diet pills to control weight in girls in early adolescence. DESIGN: We matched and randomly assigned 10 middle schools to an intervention or a control condition in a randomized controlled trial. Longitudinal multivariable analyses using generalized estimating equations were conducted with data from 480 girls to examine the effects of the intervention on the risk of reporting a new case of purging or diet pill use to control weight at follow-up 21 months later, while controlling for ethnicity and school matched pairs. Girls who reported purging or using diet pills at baseline were excluded from analyses. SETTING: Middle schools. PARTICIPANTS: Four hundred eighty girls in early adolescence aged 10 to 14 years (mean age, 11.5 years). INTERVENTION: The Planet Health obesity prevention program was implemented during 2 school years and was designed to promote healthful nutrition and physical activity and to reduce television viewing. OUTCOME: Reduced risk of using self-induced vomiting/laxatives or diet pills to control weight in the past 30 days. RESULTS: After the intervention, we found 14 (6.2%) of 226 girls in control schools and 7 (2.8%) of 254 girls in intervention schools reported purging or using diet pills to control their weight (P = .003). In a multivariable generalized estimating equation model, girls in intervention schools were less than half as likely to report purging or using diet pills at follow-up compared with girls in control schools (odds ratio, 0.41; 95% confidence interval, 0.22-0.75). CONCLUSION: These findings provide promising evidence that school-based interventions may effectively integrate prevention of both obesity and disordered weight-control behaviors.
The purposes of this study were to develop an instrument capable of assessing factors potentially related to disordered eating and weight control behaviors among university students and then to compare male and female students on these factors. A 90 item instrument was developed. Sixty-four items were written by these authors, such that eight items would assess each of eight identified factors related to disordered eating. Additionally, all 26 items from the Eating Attitudes Test (EAT-26) were included and interspersed within the instrument. The instrument was administered to 502 female university students and their responses were factor analyzed. Ten factors were identified. The instrument was then administered to 94 female and 76 male university students. Results indicate that compared to males, females report a greater desire to be thin, less tolerance for cold, more frequent use of laxatives, and a greater occurrence of eating in response to internal and external cues. There were no other sex differences. The students in this study appeared to be engaging in appropriate health practices.
The purpose of this study was to evaluate the feasibility and effectiveness of V.I.K. (Very Important Kids), a school-based, multi-component intervention designed to prevent teasing and unhealthy weight-control behaviors among fourth through sixth grade students. The effectiveness of the V.I.K. intervention was evaluated using a pre-post quasi-experimental design with one school assigned to each condition: intervention and assessment-only control. Data were collected at baseline and at 8-month post-test among 63 students at the intervention school and 57 students at the control school. The V.I.K. intervention included an after-school program, a theater program, school environment components and a family component. Process data suggest that the V.I.K. program can feasibly be implemented within a school setting and can effectively engage students, school staff and parents. Analysis of impact data revealed that the percentage of students reporting being teased decreased significantly in the intervention school relative to the control school, after controlling for baseline levels of teasing, body mass index z score and demographic factors (odds ratio = 0.22; 95% confidence interval = 0.06, 0.88; P = 0.03). These findings provide promising evidence that multi-component, school-based interventions may effectively reduce teasing in elementary schools. Future research of interventions aimed at preventing teasing using a larger sample of schools is warranted.
A new programming language SORCA has been defined and a compiler has been written for Z80-based microcomputer systems with CP/M operating system. The language was developed to control behavioral experiments by external stimuli and by time schedule in real-time. Eight binary hardware input lines are sampled cyclically by the computer and can be used to sense switches, level detectors and other binary information, while 8 binary hardware output lines, that are cyclically updated, can be used to control relays, lamps, generate tones or for other purposes. The typical reaction time (cycle time) of a SORCA-program is 500 microseconds to 1 ms. All functions can be programmed as often as necessary. Included are the basic logic functions, counters, timers, majority gates and other complex functions. Parameters can be given as constants or as a result of a step function or of a random process (with Gaussian or equal distribution). Several tasks can be performed simultaneously. In addition, results of an experiment (e.g., number of reactions or latencies) can be measured and printed out on request or automatically. The language is easy to learn and can also be used for many other control purposes.
1. Multiple microelectrode maps of the hand representation within and across the borders of cortical area 3b were obtained before, immediately after, or several weeks after a period of behaviorally controlled hand use. Owl monkeys were conditioned in a task that produced cutaneous stimulation of a limited sector of skin on the distal phalanges of one or more fingers. 2. Analysis of microelectrode mapping experiment data revealed that 1) stimulated skin surfaces were represented over expanded cortical areas. 2) Most of the cutaneous receptive fields recorded within these expanded cortical representational zones were unusually small. 3) The internal topography of representation of the stimulated and immediately surrounding skin surfaces differed greatly from that recorded in control experiments. Representational discontinuities emerged in this map region, and "hypercolumn" distances in this map sector were grossly abnormal. 4) Borders between the representations of individual digits and digit segments commonly shifted. 5) The functionally defined rostral border of area 3b shifted farther rostralward, manifesting either an expansion of the cutaneous area 3b fingertip representation into cortical field 3a or an emergence of a cutaneous input zone in the caudal aspect of this normally predominantly deep-receptor representational field. 6) Significant lateralward translocations of the borders between the representations of the hand and face were recorded in all cases. 7) The absolute locations--and in some cases the areas or magnifications--of representations of many skin surfaces not directly involved in the trained behavior also changed significantly. However, the most striking areal, positional, and topographic changes were related to the representations of the behaviorally stimulated skin in every studied monkey. 3. These experiments demonstrate that functional cortical remodeling of the S1 koniocortical field, area 3b, results from behavioral manipulations in normal adult owl monkeys. We hypothesize that these studies manifest operation of the basic adaptive cortical process(es) underlying cortical contributions to perception and learning.
Locomotor movements are generally considered to be established by integrating the activities of the neuronal mechanisms related to each of the "automatic" and "volitional" control. As one of the neuronal mechanisms contributing to such integration, the possible roles played by the ponto-medullary reticular formation have recently been reexamined. As is well established, cells in the ponto-medullary reticular formation are related to arousal behavior, and the reticular formation itself is one of the major sources for generalized motor drive. In intact, awake cats, electrical stimulation delivered directly or indirectly to the reticular formation can evoke locomotor movements accompanied by an "alerting response" and preceded by postural adjustments adequate for locomotion. Microinjection of bethanechol, a short-acting cholinergic agonist, into the pontine reticular formation results in a peculiar modification of posture and, as a consequence, locomotor movements, even changing the arousal level of the animals. The cats with bilateral tegmental lesions in the pons exhibit locomotor movements during a state of rapid eye movement sleep without atonia. It is conceivable that the ponto-medullary reticular formation contributes greatly to the integration of neuronal activities related to automatic and volitional control of locomotor movements so as to establish a goal-directed behavioral locomotor movement.
Exposure to polychlorinated biphenyls (PCBs) has been shown to detrimentally affect learning and memory in children as well as schedule-controlled behavior in experimental animals. The objective of the present series of experiments was to extend research into the effects of PCBs on behavior maintained under both short (30 s) and long (5 min) fixed-interval (FI) schedules as well as an FI 3-min with reinforcement omission. Long-Evans rats were exposed to 0 or 6 mg/kg/day Aroclor 1254 (A1254) via oral gavage from Gestation Day 6 (GD 6) through Postnatal Day 21 (PND 21). At approximately PND 90, acquisition and steady-state performance were assessed under a series of FI reinforcement schedules consisting of FI 30-s, FI 5-min, and FI 3-min with 33% of the scheduled reinforcers omitted. Performance measures included index of curvature (IOC), response rate, and postreinforcement pause (PRP). There were no effects of A1254 on the acquisition of behavior under the FI 30-s schedule. Subsequently, there was an initial decrease in response rate and IOC and an increase in PRP following the transition from FI 30-s to the FI 5-min; there were, however, no treatment-related effects on any measure. During the reinforcement-omission procedure, there was an increase in the rate of responding and a decrease in IOC and PRP following omission intervals irrespective of treatment. These data are inconsistent with previous findings and suggest that perinatal A1254 exposure in the rat does not disrupt temporally organized behavior.
Male Sprague-Dawley rats were trained to barpress under a FL-300 sec schedule of food presentation until responding patterns were stable. The effects of the ketamine optical isomers (enantioners) on this schedule-controlled behavior were examined over a dose range of 3.75 to 60 mg/kg i.p. At doses of 15 mg/kg and above, (-)-ketamine increased rate of responding, with a maximum increase of about 3 times control rate. This effect was rate-dependent, being more marked at lower control rates. In contrast (+)-ketamine did not increase overall fixed-interval response rate at any dose, but decreased rate of responding in a rate-dependent fashion at doses of 30 mg/kg and above. Spontaneous locomotor activity was increased about equally by equimolar doses of both enantiomers.
One of the most effective treatments for children with Attention Deficit Disorder with Hyperactivity (ADDH) has been the prescription of methylphenidate (MPH). While laboratory-based evidence indicates that MPH effects may be rate-dependent, little is known about changes evinced in operant behavior controlled by complex reinforcement schedules. The present study examined the effects of several doses of MPH on the operant key-pressing behavior of 20 children with ADDH who were favorable responders to the drug. Following a drug-free training period, each child performed the task across all doses in a randomly assigned sequence under double-blind placebo control conditions. Rate-dependent effects were found for both high- and low-rate reinforcement schedules. The strength of these effects varied across dose. These results have implications for the nature of rate-dependent phenomena in humans and investigations of treatment parameters in the pharmacotherapy of children with ADDH.
Contemporary theories of associative learning require cues be trained in compound for cue competition (interference) to occur. That is, Cues A and X should compete for behavioral control only if training consists of AX-outcome (O) trials and not if each cue is separately paired with O (i.e., X-O and A-O). Research with humans challenges this view by showing that A-O trials interpolated between training and testing of a X-O association impair responding to X (i.e., retroactive interference). In six conditioned suppression studies with rats, the authors demonstrate that two cues trained apart can each interfere with the potential of the other to predict the outcome. The authors conclude that this type of interference (a) reflects a failure to retrieve the target association due to priming at test of the interfering association and (b) is attenuated if the outcome is of high biological significance. These findings parallel previous reports in verbal learning research and suggest that a similar associative structure underlies some types of associations in nonverbal subjects.
To examine the assertion that changes in nucleus accumbens (NAC) dopamine (DA) activity serve as a mechanism of lead (Pb)-induced disruption of fixed interval (FI) schedule-controlled behavior, the effects of intra-NAC administration of the irreversible DA antagonist EEDQ (N-ethoxycarbonyl-2-ethoxy-1,2-dihyroquinoline) and of dopamine itself on FI performance were compared in rats that had been chronically exposed to 0, 50 or 500 ppm Pb acetate in drinking water from weaning. Pb exposure per se (500 ppm), as in past studies, increased FI response rates, primarily by shortening interresponse times. Although DA, which produced rate-dependent effects, increased FI rates at low doses in the 0 and 50 ppm groups, it did so by decreasing postreinforcement pause times. All DA doses decreased rates in the 500 ppm group. In contrast, the DA antagonist EEDQ suppressed FI response rates, effects that were not strongly rate dependent, by increasing both postreinforcement pause values and mean interresponse times. Pb exposure (500 ppm) delayed the recovery of response rates to control levels at the highest EEDQ dose, raising the possibility of a delay in receptor production rate. Collectively, these data suggest that NAC DA activity may be an important modulator of FI response rates. Enhanced NAC DA activity may contribute to Pb-associated increases in FI rates and may underlie the differential response of control and 500 ppm Pb-treated groups to intra-NAC DA administration. The different processes by which DA and Pb increase FI rates, however, suggests that additional mechanisms are operative in the case of Pb.
The purpose was to examine the sociodemographic characteristics of adolescents who read magazine articles about dieting/weight loss and the relationship between reading these types of magazine articles and psychosocial well-being and weight control behaviors. Dieting-related magazine exposure was associated with indicators of psychosocial distress and unhealthy dieting; interventions that address media consumption should reach out to all youth regardless of ethnic and social backgrounds
Cognitive-behavioral approaches appear to offer a viable alternative for the management of arthritis pain. Controlled studies have documented the efficacy of CBT protocols for managing pain in individuals having OA and RA. Preliminary studies examining the efficacy of CBT for FM patients have also yielded encouraging results. A number of clinical and research issues need attention if CBT is to be incorporated into rheumatology practice settings. These issues include identifying the most important components of CBT, developing strategies for matching CBT interventions to patients' readiness for behavior change, testing the efficacy of different therapy formats (e.g., individual versus group), broadening the scope of CBT to address issues other than pain, and insurance reimbursement.
Schedule-controlled responding was maintained under a multiple fixed-interval, fixed-ratio schedule in pigeons. Dose-related decreases in response rates were produced by clonidine (0.001-0.1 mg/kg) and morphine (0.3-5.6 mg/kg). Chronic administration of morphine produced (1) tolerance to effects of morphine, as evidenced by a decrease in potency of morphine and (2) sensitivity to opioid antagonists, as evidenced by an increase in potency of naloxone. Dose-effect curves for clonidine were not appreciably altered by chronic morphine administration.
PURPOSE: The purpose of this study was to compare parents' acceptance of passive restraint with their personal perception of their own anxiety, their evaluation of their child's emotional state while being restrained and the treating dentist's perception of their levels of stress. METHODS: A convenience sample of 100 children who needed passive restraint in order to complete their restorative dental needs were included in the study. After the dental treatment was completed, surveys were mailed to the parents who were in the operatory during the restorative procedure, asking them to evaluate their level of stress, their view of how their child accepted the passive restraint device and their view of the success of the procedure. The treating dentist also evaluated their apparent levels of apprehension and the behavior of the children while being restrained, using the Sarnat Scale. There were 42 replies to the survey. RESULTS: The results showed that the difference between the percentage of parents that felt no anxiety vs. moderate to severe anxiety was not significant. Ten percent of the parents felt their child did not mind being restrained, while the balance was evenly split between feeling that their child was either unhappy but accepting or unhappy and not accepting of restraint. CONCLUSIONS: For the population studied, the use of passive restraint was acceptable to most parents, as those in this study did not view it negatively. They were clam while observing their child being treated and happy with their decision for its use. The results suggest that most parents will accept this modality for behavior control.