Stephen E. Breuning

Effects of phenytoin withdrawal on matching to sample and workshop performance of mentally retarded persons

&NA; The present study was designed to examine the effects of gradual phenytoin withdrawal on the matching to sample performance of three mentally retarded persons. The percentage of correct responses per session served as the dependent variable, and the sample and comparison stimuli were red, green, and blue illuminations of translucent response windows. With two of the subjects, the sensitivity of a workshop assembly task to phenytoin effects was explored retrospectively. The dependent variables were percentage of time on task. number of completions, and number and type of prompts required per session. The results showed that doses of phenytoin considerably lower than the suggested optimum therapeutic level impaired the performance of mentally retarded individuals on both matching to sample and workshop assembly tasks. As doses were reduced for each subject, there were increases in the percentage of correct responding on the matching to sample task with the highest percentage correct being obtained after, and only after, the 0‐mg dose was reached. In the workshop setting, the greatest number of assemblies completed and the lowest number of prompts required occurred only after the 0‐mg dose was reached. The results are discussed in terms of generality, the tasks being well suited to the study of drug effects with mentally retarded individuals, and implications for habilitation.

Analysis of single-double blind procedures, maintenance of placebo effects and drug induced dyskinesia with mentally retarded persons.

Abstract The present study examined the importance of reliability checks, placebo conditions, and double blind conditions in assessing medication effects with ten institutionalized mentally retarded persons. In addition, a procedure for discontinuing the use of placebo and double blind conditions was explored and all residents received weekly assessments and one year follow-up of withdrawal and persistent dyskinesia. The results empirically demonstrate the importance of using reliability checks, placebo conditions, and double blind conditions. The procedure for discontinuing placebo-double blind conditions was effective and is discussed in terms of ethical and practical issues concerning their use in institutions. Placebo effects were observed to last 12 or more weeks and are discussed in terms of being maintained via operant variables. Withdrawal dyskinesias were present in nine of the ten residents and a 1.5 year follow-up showed persistent dyskinesias present in six of the ten residents. Lip-mouth and tounge movements were the primary dyskinesias.

Comparison of psychotropic drug, response cost, and psychotropic drug plus response cost procedures for controlling institutionalized mentally retarded persons ☆

Abstract The present study compared the effectiveness of psychotropic drug, response cost, and psychotropic drug plus response cost procedures in controlling the inappropriate behaviors of 18 institutionalized mentally retarded persons. Subjects were randomly assigned to one of two sequences. Sequence 1 utilized 11 subjects and was drug, drug plus response cost, then response cost. Sequence 2 utilized seven subjects and was drug, placebo (no drug), then response cost. Subjects and staff were blind to conditions and sequences. The results showed that the frequencies of inappropriate behaviors were lowest during the response cost conditions. The drug, drug plus response cost, and placebo conditions resulted in similar frequencies of inappropriate behaviors. These frequencies were approximately 45% higher than those obtained during the response cost conditions. Withdrawal dyskinesias and symptoms were present in 13 of the 18 subjects and a one year follow-up showed persistent dyskinesias present in 7 of the 18 subjects. Results are discussed in terms of drug-behavior interactions and legal and programmatic implications for habilitative training with mentally retarded persons.

Effects of methylphenidate on the fixed-ratio performance of mentally retarded children☆

The effects of methylphenidate on the lever-pressing of 12 mentally retarded children maintained under fixed-ratio 5, 10 and 20 schedules of food delivery were examined. For five children, methylphenidate at oral doses of 0.3, 0.7 and 1.0 mg/kg produced generally dose-dependent decreases in response rates, whereas for the other seven children the two lower doses increased response rates while the highest dose decreased responding. The differential effects of methylphenidate across participants could not be attributed to differences in control response rates or demographic factors. However, each child whose rate of fixed-ratio responding was increased by methylphenidate also demonstrated a therapeutic response to the drug.

Medication regimen: A subject characteristic rarely reported in behavior modification studies

The present study determined whether articles describing attempts to alter behavior in mentally retarded participants through nonpharmacological interventions typically specify whether participants received medication during the experiments. From 1978 through 1982, the vast majority of such articles published in the American Journal of Mental Deficiency, Behavior Modification, Behavior Therapy, the Journal of Applied Behavior Analysis, and Mental Retardation failed to specify whether participants were receiving drugs. In addition, very few articles examined pharmacological interventions or attempted to address the interaction of drug and nondrug treatments.

A review and analysis of applied research in mental retardation: 1975–1980

A review of the number and type of studies in mental retardation published in six prominent journals was made. Variables examined included whether the study was applied or not and in the latter case, whether the study was an assessment, treatment or epidemiological paper. Other variables evaluated were length of follow-up, frequency of applied studies published in each journal, whether subjects were children or adults, inpatients or outpatients, level of mental retardation and form of treatment employed. Implications of the present studies with regard to future directions of applied research are discussed.

Second-Order Schedule Effects With Goldfish: A Comparison of Brief-Stimulus, Chained, and Tandem Schedules

AbstractThe performance of goldfish was examined under two-component chained and tandem food reinforcement schedules with and without brief stimuli added. Both food-paired and nonpaired brief stimuli were evaluated under conditions in which each component schedule was a fixed-interval 90- sec and the operant response was contact with the feeder tube. In general, the chained schedule engendered a higher rate of responding than the tandem schedule. Responding within a schedule occurred at the highest rate when a food-paired brief stimulus (tone) was used. The brief stimulus not paired with food had little effect on responding. Under both the tandem and chained schedules, a pronounced pattern of positively accelerated responding was observed within the initial component when the food-paired brief stimulus was presented. These results indicate that in goldfish, as in better studied species, a briefly presented food-paired stimulus is a more effective conditioned reinforcer than the presentation of a discriminative stimulus associated with a schedule component under which food is earned, which is in turn more effective than a nonpaired brief stimulus.

Overtraining Extinction Effect for Goldfish (Carassius a Ura Tus) Experiencing Classical Conditioning With An Aversive Us

Restrained goldfish experienced 25, 50, 75, or 150 forward conditioning trials with a 9.5-sec conditioned stimulus-unconditioned stimulus (CS-US) interval. The CS was a light, click, or weak electric shock. A transducer monitored US-induced cessation of breathing, unconditioned response (UR), and the decrease in breathing that occurred to the CS after repeated pairings of the CS and US. Following classical conditioning training each fish experienced 25 extinction trials with the CS that it experienced during acquisition. An overtraining extinction effect was obtained; i.e., resistance to extinction for fish with 150 acquisition trials was lower than resistance to extinction for fish with 75 acquisition trials. The overtraining extinction effect was present for a greater number of trials when the CS was a weak shock as opposed to a light or click. Groups with 175 forward conditioning trials indicated that the overtraining extinction effect was not a result of deterioration of the fish across days of training. Control groups with CS alone, US alone, or random CS, US presentations showed that the overtraining extinction effect was a result of extinction of a true conditioned response.

Reinforcement effects on the intelligence test performance of institutionalized retarded adults: behavioral analysis, directional control, and implications for habilitation.

Abstract Forty mentally retarded individuals participated in a study designed to examine the relationship between increases and decreases in intelligence test scores and the availability of habilitative programs. Several test administrations were included to allow for analyses across successive conditions and examinations of both interest and intratest peformance were included. The results showed that reinforcement for correct responding increased IQs and reinforcement for incorrect responding decreased IQs. Concomitant with increases and decreases in IQs were increases and decreases in the availability of habilitative programs. These increases and decreases occurred independent of participant performance in the programs. The results are discussed in terms of a behavioral analysis and implications for habilitation.