ACHIEVING AND MAINTAINING COMPLIANCE WITH THE KETOGENIC DIET

The ketogenic diet, a treatment for intractable epilepsy, is rarely initiated because it requires strict compliance with a diet that is perceived to be unpalatable. In a case study of a 15-year-old girl with uncontrolled epilepsy, we used a stimulus-choice procedure to assess relative preferences of 33 foods from the diet and to develop two treatments based on Premack's principle. The results of a multielement analysis showed that both treatments increased dietary compliance. Compliance was maintained with generalization of treatment across settings, and was associated with a 40% reduction in seizures.     

THE TREATMENT OF COVERT SELF-INJURY THROUGH CONTINGENCIES ON RESPONSE PRODUCTS

Assessment and treatment of covert self-injurious behavior are complicated because it is difficult to quantify and apply differential consequences to covert responses. In this study, both tangible and social reinforcers were identified using reinforcer assessment methods. These reinforcers were then provided contingent upon the absence of tissue damage identified during physical examinations, resulting in near 100% success in physical assessment checks that was maintained over 10 months.     

THE EFFECTS OF CONTINGENT AND NONCONTINGENT ATTENTION ON SELF-INJURY AND SELF-RESTRAINT

Self-restraint and self-injurious behavior (SIB) are two responses that can sometimes be members of the same functional response class (i.e., maintained by the same contingency). In such cases, a single treatment should be effective for both responses. In this investigation, we examined the effects of providing attention (the presumed reinforcer) both noncontingently and contingent upon either SIB or self-restraint. Results were consistent with our hypothesis that both responses were maintained by attention and suggested that noncontingent reinforcement was a potentially effective treatment.     

A PRELIMINARY PROCEDURE FOR PREDICTING THE POSITIVE AND NEGATIVE EFFECTS OF REINFORCEMENT-BASED PROCEDURES

In the current investigation, a modification was made to the preference assessment described by Pace, Ivancic, Edwards, Iwata, and Page (1985) to predict the effects of stimuli when used in a differential-reinforcement-of-other-behavior (DRO) schedule for 2 clients with severe self-injurious behavior (SIB) and profound mental retardation. Based on the results of the preference assessment, three types of stimuli were identified: (a) high-preference stimuli associated with high rates of SIB (HP/HS), (b) high-preference stimuli associated with relatively lower rates of SIB (HP/LS), and (c) low-preference stimuli associated with low rates of SIB (LP/LS). Consistent with the results of the preference assessment, the DRO schedule with HP/HS stimuli resulted in increased SIB, and the DRO schedule with LP/LS stimuli resulted in no changes in SIB. HP/LS stimuli were demonstrated reinforcers but did not result in a change in SIB when used in a DRO schedule. Thus, the stimulus preference assessment may be useful clinically in some situations for predicting both the beneficial and the negative side effects of stimuli in DRO procedures.     

Repetition blindness and bilingual memory: Token individuation for translation equivalents

The repetition blindness effect (RB) occurs when individuals are unable to recall a repeated word relative to a nonrepeated word in a sentence or string of words presented in a rapid serial visual presentation task. This effect was explored across languages (English and Spanish) in an attempt to provide evidence for RB at a conceptual level using noncognate translation equivalents (e.g.,nephew-sobrino). In the first experiment, RB was found when a word was repeated in an English sentence but not when the two repetitions were in different languages. In the second experiment, RB was found for identical repetitions in Spanish and in English using word lists. However, the crosslanguage condition produced significant facilitation in recall, suggesting that although conceptual processing had taken place, semantic overlap was not sufficient to produce RB. The results confirm Kanwisher’s (1987) token individuation hypothesis in the case of translation equivalents.     

Cognitive Impairment and Its Relationship to Psychopathic Tendencies in Children with Emotional and Behavioral Difficulties

This study investigated whether performance on the card playing task (Newman, Patterson, & Kosson, 1987) and the moral/conventional distinction measure predict level of childhood conduct problems as indexed by the Psychopathy Screening Device (Frick & Hare, in press). The card-playing task indexes the child's sensitivity to changes in reinforcement rate. The moral/conventional distinction measure indexes the child's sensitivity to the difference between moral transgressions which result in harm to another from conventional transgressions which more usually result in social disorder. The Psychopathy Screening Device indexes a behavioral syndrome that consists of two dimensions: affective disturbance and impulsive and conduct problems. Thirty-nine children with emotional and behavioral difficulties were presented with both measures. Performance on both measures did predict extent of behavioral disturbance. Moreover, there was a significant association between performance on the card playing tasks and the moral/conventional distinction. The results are interpreted within the response set modulation and violence inhibition mechanism models and by reference to recent work at the anatomical level.     

ASSESSMENT AND TREATMENT OF DESTRUCTIVE BEHAVIOR MAINTAINED BY STEREOTYPIC OBJECT MANIPULATION

In the current investigation, 2 participants with mental retardation displayed property destruction and stereotypy, and both responses involved the same materials (e.g., breaking and tapping plastic objects). Three experiments were conducted (a) to indirectly assess the functions of these two responses, (b) to determine their relation to one another, and (c) to develop a treatment to reduce the more serious behavior, property destruction. In Experiment 1, previously destroyed materials were either present or absent, and their presence reduced property destruction but not stereotypy. In Experiment 2, matched toys (ones that produced sensory stimulation similar to stereotypy) were either present or absent, or were replaced by unmatched toys (for 1 participant). Matched toys produced large reductions and unmatched toys produced small reductions in property destruction and stereotypy. In Experiment 3, attempts to pick up undestroyed objects were either blocked or not blocked while matched toys were continuously available. Response blocking reduced property destruction (and attempts), prevented stereotypy, and increased manipulation of matched toys. These results suggest that the two aberrant responses formed a chain (e.g., breaking and then tapping the object), which was maintained by the sensory consequences (e.g., auditory stimulation) of the terminal response, and that previously destroyed material or matched toys made the initial response (property destruction) unnecessary.     

Sexual responding of “nonrapists” to aggressive sexual themes: Normative data

The present study presents data relevant to the sexual responding to aggressive cues of a large sample of nonrapist males recruited from the community. Two hundred three subjects received physiological assessment of sexual arousal to heterosexual and rape stimuli. Results indicated that under instructions not to interfere with sexual responding, approximately 80% of the nonrapists would be correctly classified, which was significantly different from chance. However, under instructions to suppress arousal, classification was no better than chance. The rape index was not related to age, socioeconomic status, sexual experience, or amount of arousal shown in the laboratory. However, there was a small but significant relationship to IQ. Overall, the data suggest that for instructions not to interfere with responding, the error rate seen in this larger-scale sample was equivalent to that in previous studies using smaller normative samples and that classification in general is not biased by the subject characteristics measured in this study.Portions of this project were supported by USPHS Grant MH-34030-02 from the Center for the Studies of Crime and Delinquency and by Tennessee Department of Mental Health and Mental Retardation Research Contract ID-0783 to the Department of Psychiatry.     

Visual recognition memory for binary pictures: another look

Recognition memory for matrices of 0s and 1s was examined as a function of the number of elements (complexity) and density of those elements within the matrix. It was found that with greater density and lesser complexity, recognition performance improved. This result contradicts an earlier finding of Green and Purohit, who concluded that the more complicated matrices led to better performance. The present study suggests that their conclusion was erroneous and stemmed from failure to control the physical parameters of density and number of elements in the matrix. Implications for the general problem of recognition memory and eye movements are discussed.