Motivational effects of smoked marijuana: behavioral contingencies and low-probability activities.

Six adult male research volunteers, in two groups of 3 subjects each, lived in a residential laboratory for 15 days. All contact with the experimenters was through a networked computer system, and subjects' behavior was monitored continuously and recorded. During the first part of each day, they were allowed to socialize. Two cigarettes containing active marijuana (2.7% delta 9-THC) or placebo were smoked during the private work period and the period of access to social activities. Three-day contingency conditions requiring subjects to engage in a low-probability work activity (instrumental activity) in order to earn time that could be spent engaging in a high-probability work activity (contingent activity) were programmed during periods of placebo and active-marijuana smoking. During placebo administration, the contingency requirement reliably increased the amount of time that subjects spent engaged in the low-probability instrumental activity and decreased the time spent engaged in the high-probability activity. During active-marijuana administration, however, the increases in instrumental activity were consistently larger than observed under placebo conditions. The decreases in contingent activity were similar to those seen under placebo conditions. Smoking active marijuana was thus observed to produce increments in instrumental activity under motivational conditions involving contingencies for "work activities."     

Effects of ethanol on reinforced variations and repetitions by rats under a multiple schedule.

Response sequences emitted by five Long-Evans rats were reinforced under a two-component multiple schedule. In the REPEAT component, food pellets were contingent upon completion of a left-left-right-right (LLRR) sequence on two levers. In the VARY component, pellets were contingent upon variable sequences (i.e., a sequence was reinforced only if it differed from each of the previous five sequences). The rats learned to emit LLRR sequences in the REPEAT component and variable sequences in VARY. Intraperitoneal injections of ethanol (1.25, 1.75, and 2.25 g/kg) significantly increased sequence variability in REPEAT, thereby lowering reinforcement probability, but had little effect on sequence variability in the VARY component. These results extend previous findings that alcohol impairs the performance of reinforced repetitions but not of reinforced variations in response sequences.     

DECREASING BURNED CHILDREN'S PAIN BEHAVIOR: IMPACTING THE TRAUMA OF HYDROTHERAPY

We evaluated the effects of cartoon viewing with the use of a star feedback chart on two burned children's pain behavior during their physical therapy sessions. In addition, the degree to which the observational data corresponded with physical therapists' and mothers' ratings of the children's pain, fear, and cooperativeness was examined. Using a reversal single-subject design, the results showed that the children's pain behavior substantially decreased during experimental treatment sessions compared to their baseline levels. The rating scale data indicated that the physical therapist's and mother's rating of pain, anxiety, and cooperativeness were all correlated significantly with the observational data (p < .05). The contributions of respondent and operant conditioning to the occurrence and treatment of pain behavior in burned children are discussed.     

OPERANT TREATMENT OF OROFACIAL DYSFUNCTION IN NEUROMUSCULAR DISORDERS

The popularity and reported success of biofeedback treatment for neuromuscular disorders has occurred despite a lack of research identifying the critical variables responsible for therapeutic gain. In this study, we assessed the degree to which severe neurological dysfunction could be improved by using one of the components present in all biofeedback treatment, contingency management. Three cases of orofacial dysfunction were treated by reinforcing specific improvements reliably detectable without the use of biofeedback equipment. The results showed that contingency management procedures alone were sufficient to improve overt motor responses but, unlike biofeedback treatment, did not produce decreases in the hypertonic muscle groups associated with the trained motor behavior. The findings suggest that sophisticated, expensive biofeedback equipment may not be necessary in treating some neuromuscular disorders and that important clinical gains may be achieved by redesigning the patient's daily environment to be contingently therapeutic, rather than only accommodating the disabilities of the physically handicapped.     

BEHAVIORAL ASSESSMENT AND TREATMENT OF CHRONIC FOOD REFUSAL IN HANDICAPPED CHILDREN

In this study, we examined the eating behavior of four handicapped children, none of whom exhibited self-feeding skills. All children had a history of food refusal and were nutritionally at risk; one child received all nourishment by way of a gastrostomy tube. Baseline data taken during mealtimes indicated that all children accepted very little food, expelled food frequently, and engaged in a number of disruptive behaviors. Treatments consisted of one or more of the following contingent events: social praise, access to preferred foods, brief periods of toy play, and forced feeding. Results of multiple-baseline and reversal designs showed marked behavioral improvement for each child and increases in the amount of food consumed. Further improvements were noted at follow-up, which ranged from 7 to 30 months posttreatment.     

The relaxation word of the day: A simple technique to measure adherence to relaxation

A new procedure of assessing adherence to home practice of relaxation is presented. The technique involved the subject identifying one of four possible relaxation words of the day at the end of a taped relaxation session. The method was employed to assess the relationship between adherence to relaxation and decline of blood pressure during a 10-session/8-week relaxation program involving 17 hypertensive subjects. No statistically significant relationship was found on either a short-term or a long-term basis. An advantage of the assessment technique is that it appears easily integrated into the overall therapeutic objective for relaxation therapy; a disadvantage is that the subject needs to comply not only with the relaxation schedule but also with the monitoring procedure.This research study was funded by NIH Grant HL27159.     

Utilization and predicted trends of behavioral inventories

Published articles (N=1703) during the period 1975 to 1982 in three behavioral journals (Behavior Therapy, Journal of Behavior Therapy and Experimental Psychiatry, andJournal of Applied Behavior Analysis) were reviewed for the utilization of preintervention and categories of behavioral inventories. Results revealed that (a) the three forms of the Fear Survey Schedule (FSS) and the Social Avoidance and Distress Scale (SADS) were the most utilized traditional behavioral measures, (b) new self-developed inventories were reported with significantly (p<.05) different frequencies across the three journals, (c) numerous published inventories beyond the traditional FSS and SADS were reported, and (d) an expanded use of IQ measures in preintervention behavioral assessment was also found. Trends regarding the nature of behavioral inventories among the three journals and a discussion on advances in behavioral assessments are presented.     

Positive behavioral contrast when pigeons press treadles during multiple schedules

Pigeons were placed on multiple variable-interval 15-second variable-interval 15-second and on multiple variable-interval 15-second extinction schedules in which treadle presses produced food reinforcers. Positive behavioral contrast occurred. That is, rates of responding were higher during the variable-interval 15-second component when the other component was extinction than when it was another variable-interval 15-second schedule. These results contradict the findings of other studies, which failed to find positive contrast when pigeons pressed treadles for food reinforcers. They may also question the additive theories of behavioral contrast that predict that contrast should not occur in this situation.     

Quantification of rats' behavior during reinforcement periods

What is treated as a single unit of reinforcement often involves what could be called a reinforcement period during which two or more acts of ingestion may occur, and each of these may have associated with it a series of responses, some reflexive, some learned, that lead up to ingestion. Food-tray presentation to a pigeon is an example of such a “reinforcement period.” In order to quantify this behavior, a continuous-reinforcement schedule was used as the reinforcement period and was chained to a fixed-ratio schedule. Both fixed-ratio size and reinforcement-period duration were manipulated. Rats were used as subjects, food as reinforcement, and a lever press as the operant. Major findings included (a) a rapid decline in response rates during the first 15 to 20 seconds of the reinforcement periods, and (b) a strong positive relationship between these response rates and the size of the fixed ratio. Also revealed was a short scallop not normally found in fixed-ratio response patterns, whose length was a function of fixed-ratio size and reinforcement-period duration. It is suggested that rapidly fluctuating excitatory processes can account for many of these findings and that such processes are functionally significant in terms of behavioral compensation.     

Analysis of discriminative control by social behavioral stimuli

Visual discriminative control of the behavior of one rat by the behavior of another was studied in a two-compartment chamber. Each rat's compartment had a food cup and two response keys arranged vertically next to the clear partition that separated the two rats. Illumination of the leader's key lights signaled a “search” period when a response by the leader on the unsignaled and randomly selected correct key for that trial illuminated the follower's keys. Then, a response by the follower on the corresponding key was reinforced, or a response on the incorrect key terminated the trial without reinforcement. Accuracy of following the leader increased to 85% within 15 sessions. Blocking the view of the leader reduced accuracy but not to chance levels. Apparent control by visual behavioral stimuli was also affected by auditory stimuli and a correction procedure. When white noise eliminated auditory cues, social learning was not acquired as fast nor as completely. A reductionistic position holds that behavioral stimuli are the same as nonsocial stimuli; however, that does not mean that they do not require any separate treatment. Behavioral stimuli are usually more variable than nonsocial stimuli, and further study is required to disentangle behavioral and nonsocial contributions to the stimulus control of social interactions.