Peak shift following simultaneous discriminations.

Pigeons were exposed to stimuli presented on two keys. For some birds, the stimuli varied in a dimension of visual flicker-rate, and for others they varied in visual intensity. During differential training, concurrent schedules operated, with one stimulus correlated with one schedule and another stimulus correlated with a second schedule that arranged a lower, or zero, rate of reinforcement. The stimuli were alternated randomly on the two keys. Generalization tests were given in which the original two, and seven other stimuli lying in the same dimension, were presented in pairs on the two keys in various combinations. In the generalization test given after differential training, each bird showed peak shift. The data did not support explanation for peak shift that gave critical emphasis to whether stimuli were presented simultaneously or successively during differential training.

Preference for unsegmented interreinforcement intervals in concurrent chains.

Five pigeons were trained under concurrent-chain schedules in which a pair of independent, concurrent variable-interval 60-s schedules were presented in the initial link and either both variable-interval or both fixed-interval schedules were presented in the terminal link. Except for the baseline, one of the terminal-link schedules was always a two-component chained schedule and the other was either a simple or a tandem schedule of equal mean interreinforcement interval. The values of the fixed-interval schedules were either 15 s or 60 s; that of the variable-interval schedules was always 60 s. A 1.5-s changeover delay operated during the initial link in some conditions. The pigeons preferred a simple or a tandem schedule to a chain. For the fixed-interval schedules, this preference was greater when the fixed interval was 60 s than when it was 15 s. For the variable-interval schedules, the preferences were less pronounced and occurred only when the changeover delay was in effect. For a given type of schedule and interreinforcement interval, similar preferences were obtained whether the nonchained schedule was a tandem or simple schedule. The changeover delay generally inflated preference and lowered the changeover rate, especially when the terminal-link schedules were either short (15 s) or aperiodic (variable-interval). The results were consistent with the notion that segmenting the interreinforcement interval of a schedule into a chain lowers the preference for it.

Preference for less segmented fixed-time components in concurrent-chain schedules of reinforcement.

A concurrent-chain procedure was used to examine choice between segmented and less segmented response-independent schedules of reinforcement. A pair of independent, concurrent variable-interval 60-s schedules were presented in the initial link, along with a 1.5-s changeover delay. A chained fixed-interval fixed-time and its corresponding tandem schedule constituted the terminal links. The length of the fixed-interval schedule in the terminal link was varied between 5 s and 30 s while that of the fixed-time schedule was kept at 5 s over conditions. The first components of both terminal-link schedules were accompanied by the same stimulus. Except in the baseline condition, the onset of the second component of the terminal-link chained schedule was accompanied by either a localized (key color) or a nonlocalized (dark houselight) stimulus change. Stimulus conditions were constant during the terminal-link tandem schedule. With three exceptions, pigeons demonstrated a slight preference for the tandem over the chained schedule in the terminal link. Furthermore, this preference varied inversely with the length of the first component. In general, these results are consistent with previous studies that reported an adverse effect on choice by segmenting an interval schedule into two or more components, but they are inconsistent with studies that reported preference for signaled over unsignaled delay of reinforcement.

Inhibitory stimulus control in concurrent schedules.

Six pigeons were exposed to two keys, a main key and a changeover key. Pecking the main key was reinforced on a variable-interval 5-min schedule when the key was blue and never reinforced when the key displayed a vertical line on a blue background. Each peck on the changeover key changed the stimulus displayed on the main key. Each subject was given two generalization tests, consisting of presentations on the main key of six orientations of the line on the blue background, with no reinforcements being given. In one test changeover-key pecks changed the stimulus; in the other test the changeover key was covered and the experimenter controlled stimulus changes. Both responses to the six stimuli and time spent in the presence of the stimuli gave U-shaped gradients when the changeover key was operative. With most subjects, absolute rates of responding to each stimulus produced unsystematic gradients, whether or not the changeover key was operative.

Peak shift in concurrent schedules.

Pigeons were exposed to two keys, a main key and a changeover key. Initially non-differential training was given in which pecking the main key was reinforced on a variable-interval 2-min schedule when the key displayed the first stimulus, a black line on a blue background, and was reinforced on an identical but independent variable-interval 2-min schedule when the key displayed a plain blue stimulus. Later, differential training was given in which pecking the main key was reinforced on a variable-interval 2-min schedule when the first stimulus was displayed; and was reinforced on a variable-interval 10-min schedule when a second stimulus, a black line of another orientation on a blue background, was displayed. During non-differential and differential training, each peck on the changeover key changed the stimulus on the main key. Generalization tests were given before and after the differential training. These consisted of presentations on the main key of seven orientations of the black line on the blue background, including the first and second stimuli, with no reinforcements being given. Changeover-key pecks changed the stimuli on the main key. Generalization gradients were obtained using three measures: time spent, responses, and response rate in the presence of each test stimulus. Typically, maximum values on these measures occurred to stimuli away from the first in a direction opposite the second stimulus, and minimum values occurred to stimuli away from the second in a direction opposite the first.

Preference for simple interval schedules of reinforcement in concurrent chains: Effects of segmentation ratio.

A concurrent-chains procedure was used to examine pigeons' preferences between segmented and unsegmented terminal-link schedules of reinforcement. During the initial link, a pair of independent, concurrent variable-interval 60-s schedules was in effect. In the terminal link, reinforcement was provided by a chain fixed-interval fixed-interval schedule on one key and by a simple fixed-interval schedule with an equal interreinforcement interval in the other. The relative duration between the first and second components (segmentation ratio) in the terminal-link chained schedule was systematically varied while the terminal-link duration was kept constant at either 15 s or 30 s in two sets of conditions. With few exceptions, the simple schedule was preferred to the chained schedule. Furthermore, this preference was inversely related to the size of the segmentation ratio in the segmented schedule. When the segmentation ratio was smaller than 1:1, preference was more extreme for a 30-s condition than for a 15-s condition. However, preference decreased more rapidly in conditions with the longer terminal-link duration when the ratio increased. Taken together, these results were consistent with previous findings concerning the effect of the terminal-link duration on choice between segmented and unsegmented schedules. In addition, the data suggested that segmentation ratio in a segmented schedule constitutes another potent factor influencing preference for the unsegmented schedule.

Effects of a screening procedure on pica and collateral behaviors.

Pica, the ingestion of inedible objects, and several collateral behaviors of a profoundly retarded woman were measured before, during and after the application of a screening contingency for pica. A variant of visual screening, blindfold, was used. Inedible objects were removed from the subject's mouth, but not her hand, during both baseline and treatment. During treatment each occurrence of pica resulted in the covering of the subject's eyes with a blindfold for 1 min. Pica was rapidly suppressed as the treatment was introduced sequentially in each of three settings in a multiple baseline design. It was further reduced to near-zero levels during later ward-wide maintenance and follow-up. Antecedents of pica, picking and handling inedible objects, also decreased to low levels without receiving special attention. Other untreated collateral behaviors, stereotypy, destructive and aggressive behaviors and social interactions with staff and other residents, which occurred at various levels initially, showed generally positive changes although these were sometimes small.

Recognition of facial expressions of emotion by children with attention-deficit hyperactivity disorder.

Fifty children and adolescents were tested for their ability to recognize the 6 basic facial expressions of emotion depicted in Ekman and Friesen's normed photographs. Subjects were presented with sets of 6 photographs of faces, each portraying a different basic emotion, and stories portraying those emotions were read to them. After each story, the subject was asked to point to the photograph in the set that depicted the emotion described. Overall, the children correctly identified the emotions on 74% of the presentations. The highest level of accuracy in recognition was for happiness, followed by sadness, with fear being the emotional expression that was mistaken most often. When compared to studies of children in the general population, children with ADHD have deficits in their ability to accurately recognize facial expressions of emotion. These findings have important implications for the remediation of social skill deficits commonly seen in children with ADHD.

Treating self-injury: water mist spray versus facial screening or forced arm exercise.

In three experiments, the effect of water mist spray on self-injurious and collateral behaviors was compared with either facial screening or forced arm exercise. Water mist spray was as effective as facial screening in suppressing face-slapping in Experiment 1. However, it was not as effective as facial screening for self-injurious finger-licking in Experiment 2 or forced arm exercise for excessive ear-rubbing in Experiment 3. These results suggest that while water mist spray is effective, it may be less so than alternative procedures. In Experiments 2 and 3 there was a consistent decrease in the occurrence of untreated maladaptive behaviors. In addition, there was a moderate increase in appropriate social interaction in Experiment 2 and a substantial increase in Experiment 3.

Social skills training with institutionalized severely and profoundly mentally retarded persons.

This paper examines the literature on training severely and profoundly retarded individuals in social skills. Experimental studies have focused mainly on three areas: (1) cooperative responding during play, (2) non-verbal physical or close-proximity interactions, and (3) conversational skills. Training procedures varied but usually involved combinations of physical and verbal prompting, modeling, shaping, and social and edible reinforcement. These studies provide strong evidence that severely and profoundly retarded individuals can be taught useful interpersonal skills and can sometimes even assist the development of these skills in their peers. In general, the studies were methodologically sound in terms of basic design and interobserver reliabilities but weak with respect to maintenance and follow-up procedures. Only some studies tested for generalization of treatment effects and only a few specifically trained for such generalization.

Controlling pica by components of an overcorrection procedure.

Previous studies have shown that pica, the ingestion of inedible objects, can be effectively controlled in mentally retarded subjects using a two- or three-component overcorrection procedure or with one of these components in conjunction with another response-reduction procedure, differential reinforcement of other behavior. The present study showed that one of the components, oral hygiene, could eliminate pica by 2 retarded subjects when used alone. Although oral hygiene was the most effective component, each of the other components, tidying and personal hygiene, did decrease pica. In a later phase we found that a number of different therapists could easily and effectively implement the oral hygiene procedure.

Suppression of pica using brief-duration physical restraint.

The present study supported the finding of Bucher et al. (1976) that physical restraint can control pica. However, unlike the earlier study which additionally used a verbal reprimand, physical restraint alone was shown to be effective. Further, this study showed that while all three durations of physical restraint suppressed pica, the duration of 10 s was more effective than either 30 s used with one subject, or 3 s used with the other in alternating treatments designs. The procedure proved simple to use, took minimal staff training time, and required no equipment. During treatment some increase in pica was observed in settings where treatment had not yet been applied but later treatment in these settings quickly controlled the behaviour. Collateral behaviours were largely unaffected except for picking and handling, a precursor for pica, which showed variable changes, with reductions being the only large changes.

Behavioral monitoring of pharmacological interventions for self-injury.

Pharmacological interventions are often the treatment of choice for controlling the maladaptive behavior of institutionalized mentally retarded children. However, the efficacy of various psychotropic drugs for controlling the behavior of given individuals has not been well established. Further, it is not always clear that decisions to alter a drug regimen are based on actual changes in the behavior of interest. The present study illustrates the use of behavioral observation to assess the effects of various drugs prescribed for the self-injurious behavior of a profoundly mentally retarded 15 year old male. The clinical effectiveness of various dosages of carbamazepine (Tegretol), thioridazine (Melleril), and chlorpromazine (Largactil) was assessed. Except for Melleril 100 mg, tid, when a marked downward trend in the daily rate was observed, no significant reduction in self-injury occurred. Subsequently overcorrection (forced arm exercise) made contingent on each response reduced self-injury to near zero, but only when the last prescribed drug, Tegretol 200 mg, tid, had been withdrawn for several days.

Increasing physicians' awareness and use of community resources for mentally retarded persons.

General practitioners must frequently deal not only with the physical health of their mentally retarded patients, but also with their psychological and emotional problems and with difficulties that their families have with coping. In the present study all general practitioners in one city were questioned about their knowledge of mental retardation, their ability to counsel families with a mentally retarded member and their knowledge and utilization of community agencies which provided services for the mentally retarded and their families. The majority of the 400 physicians who satisfactorily completed the questionnaire accepted an obligation to deal with the various problems of the mentally retarded, to counsel their families and to know about and make referrals to available community services. However most also expressed lacks in their knowledge about these various matters. Subsequently, detailed information was sent to them about the available community agencies and then sometime later they were given a second questionnaire concerning their referrals to and advice to parents about the community services. The replies indicated that the physicians now had a much greater awareness of the services available, and that they more regularly made referrals to and advised parents to use these facilities.

Effects of delayed versus immediate attention to oral reading errors on the reading proficiency of mentally retarded children.

The impact of two variations of teacher attention to oral reading errors and a no-treatment control condition were compared in an alternating treatments design. For four moderately mentally retarded children, each uncorrected oral reading error was followed by: (a) immediate teacher attention, with the teacher correcting the error word as soon as it occurred, (b) delayed teacher attention, with the teacher correcting the error word at the end of the sentence in which it occurred or within 10 to 15 seconds if the subject paused following an error, or (c) no teacher attention. Both immediate and delayed teacher attention were effective in reducing the number of uncorrected oral reading errors and increasing the number of self-corrections when compared to the no-treatment control. However, the delayed condition had greater effect than the immediate condition on both measures. In a later remediation phase, when only the delayed treatment was given, uncorrected errors remained at low levels whereas self-corrections generally increased. Total errors, whether subsequently self-corrected or not, with one exception, decreased during the study.

Suppressive effects of visual and facial screening on self-injurious finger-sucking.

Effects of following the self-injurious finger-sucking of two profoundly mentally retarded persons by 5 seconds of either visual or facial screening were compared using an alternating treatments design. The two screening procedures reduced the self-injury more than did a no-treatment control condition. Visual screening was more effective than facial screening with one of the subjects. Subsequently, when the only treatment was visual screening, the contrast in the effect on self-injury between visual screening and no-treatment was further increased. The greatest suppression occurred when visual screening was given in all sessions. Toy play reliably occurred only with appropriate training: The mere provision of toys had no impact on toy play. The effect of toy play on self-injury was equivocal. Possible limitations to the generality of the findings were discussed.

Effects of facial screening and blindfold on self-injurious behavior.

Previous research has demonstrated that a variety of maladaptive behaviors in children can be suppressed by facial screening. The effectiveness of various screening procedures for reducing self-injurious behaviors were compared in three experiments using alternating treatments designs. In Experiments 1 and 2, an immediate substantial response reduction occurred with facial screening in which visual blocking was present but not when visual blocking was absent. In Experiment 3, both facial screening with visual blocking and a blindfold procedure proved equally effective in reducing self-injury but for practical reasons, therapists preferred to use facial screening.

Effects of physical restraint on the behavior of hyperactive mentally retarded persons.

The effects of brief response-contingent physical restraint on the behavior of four hyperactive moderately or severely mentally retarded persons were investigated. Each instance of out-of-seat behavior resulted in a return to the seat followed by a 15-second physical restraint. Using a combined reversal and multiple-baseline across subjects design, we found that the out-of-seat behavior of all four subjects increased during the two implementations of the restraint contingency when compared with levels obtained during alternative baseline periods. Possible reasons for the increase in the behavior under the restraint contingency rather than the expected decrease were discussed.