IDENTIFYING THE EDUCATIVE AND SUPPRESSIVE EFFECTS OF POSITIVE PRACTICE AND RESTITUTIONAL OVERCORRECTION

Two major features of the overcorrection procedure, restitution and positive practice, were analyzed for their educative and suppressive properties in the treatment of profoundly retarded adults. Positive practice techniques that were topographically similar and dissimilar to the target behavior were studied. Eating behavior and puzzle performance were observed. Restitutional overcorrection and both forms of positive practice were effective for suppressing inappropriate behaviors. Even when appropriate behaviors had been acquired by positive practice, restitution and dissimilar positive practice were generally ineffective for increasing their rate of occurrence. However, topographically similar positive practice was successful as a means of teaching new appropriate behaviors.     

REINFORCER VARIATION: IMPLICATIONS FOR MOTIVATING DEVELOPMENTALLY DISABLED CHILDREN

Motivating developmentally disabled children to participate in educational activities can be very difficult. This is especially true for children diagnosed autistic. Because there is some evidence to suggest that stimulus variation may influence motivation, the present study investigated the effects of constant vs. varied reinforcer presentation on correct responding and on-task behavior. Results from a reversal design showed declining trends in both correct responding and on-task behavior when the same reinforcer was consistently presented, whereas, varying the reinforcers produced significantly improved and stable responding. The results are discussed in relation to the literature on stimulus variation and its effects on responsivity.     

Factors underlying the social readjustment rating scale

The Social Readjustment Rating Scale (SRRS) was administered to 185 subjects whose age ranged from 21 to 61 yr. The responses were factor analyzed for a principal axis solution followed by isopromax oblique rotation. All the items were loaded and clustered under five factors labeled as follows: (1) personal growth, maturation, and renewal; (2) tension and uncertainty; transitions in personal or occupational situations; (3) changes in one's usual routine and relationship; (4) significant changes in family or mirriage; and (5) personal catastrophies. Males scored significantly higher than females on factors 4 and 5. There were no age differences in the obtained scores. The finding of the factorial structure was thought to add credence to the scale especially in view of past criticism. Implications for future research were also discussed.     

Naturalistic observations of pathological behavior in hospitalized psychiatric patients

Naturalistic observations were conducted on 19 acutely ill psychiatric patients in the hospital ward milieu. The study was designed to determine relationships between selected social and environment variables and overt atypical behavior. Patients were observed on an individual basis with time-sampling techniques. In total, 16 pathological behaviors were coded and the most frequent (postural deviance, pace, agitation, hyperactivity, withdrawal, foot shake/body sway, leg swing) were selected in order to determine variation in frequency of these behaviors as a function of the following variables: area within hospital, week of hospitalization, distance between the focal subject and his/her nearest neighbor, number of people in an area, and time of day. Results showed differential changes in pathological behavior as a function of week of hospitalization, number of people in a given area, and distance from the focal subject's nearest neighbor. There was no significant change in the frequency of pathological behaviors as a function of area within hospital or time of day. In addition, most pathological behaviors decreased significantly when patients were engaged in the sending or receiving of verbal behavior. Cluster analyses revealed varying degrees of dissociation between pathological behaviors and social-interaction behaviors. These results support (a) a nonunitary concept of the general category pathological and (b) the view that there are inhibitory effects of social interaction on the enactment of atypical behaviors. Clinical implications of these findings are discussed.R.H.P. completed this research during his tenure as a postdoctocal fellow in the Department of Psychiatry, Human Ethology Laboratory, UCLA (NIMH Fellowship 1 F32MHO7627-01). Support for this research also came from the Veterans Administration.     

The effects of modifying consummatory behavior on the topography of the autoshaped pecking response in pigeons

The autoshaped responses of two debeaked pigeons that had developed modified eating behavior were compared to the autoshaped responses of three control subjects that ate grain normally. The control subjects exhibited keylight responding that was judged normal by two independent raters. The debeaked subjects pecked the key and ate grain with both normal and modified responses. The results of this study demostrate that an autoshaping procedure using grain as an appetitive stimulus may be used to establish a response that is not biologically preorganized.     

DINING OUT WITH CHILDREN: EFFECTIVENESS OF A PARENT ADVICE PACKAGE ON PRE-MEAL INAPPROPRIATE BEHAVIOR

The effectiveness of an advice package designed to restructure the restaurant environment and encourage parent praise was examined. Experiment 1 assessed the usefulness of the package when used with experimenter assistance. Videotapes were used to record the target child's behavior. Pre-meal inappropriate behavior decreased an average of 51% across target children. Mealtime inappropriate behavior and parent praise and disapproval were also measured. Experiment 2 was designed to determine whether families could implement the package without experimenter assistance and whether effects obtained would generalize to a different restaurant. Data were taken in vivo. Nine families were randomly assigned to one of three groups. Group assignment determined the order in which families went to two restaurants, the number of dinners each family participated in, and the point at which parents received the advice package. The order in which the families went to the two restaurants as well as the number of baseline meals was counterbalanced. Results of Experiment 2 showed that, when using the advice package, parents in all sequences were able to decrease pre-meal inappropriate behavior of their children, and that these effects generalized to a second restaurant.     

A biased random walk model for two choice reaction times

This paper generalizes Stone's (1960, Psychometrika 25, 251–260) random walk model of two choice response times (RTs) that is based on the sequential probability ratio test (SPRT) and that predicts equal correct and incorrect RTs to the same response. The generalized version allows a bias of the type found in signal detection theory to enter directly into the accumulation process so that ambivalent evidence may be seen as slightly favoring one alternative. The resulting biased SPRT model can predict any relation between correct and incorrect mean RTs. In particular, unlike the special symmetric case of Link and Heath's (1975, Psychometrika 40, 77–105) relative judgment theory (RJT), the biased SPRT model can predict that correct mean RTs are faster for one response but slower for the other. The biased SPRT model, the classical SPRT model, and the symmetric RJT model are all fit to the data of an RT deadline experiment reported by Green and Luce (1973, Attention and performance, New York: Academic Press) and it is shown that, of the three, the biased SPRT model provides the best account. Finally, a method for incorporating the same sort of bias into RJT models is sketched out.     

Preference for mixed versus constant delays of reinforcement: Effect of probability of the short, mixed delay

Preference for mixed versus constant delays of reinforcement was studied with a concurrent-chain procedure. Lever pressing by rats in concurrently available variable-interval 60-second initial links occasionally produced mutually exclusive terminal-link reinforcement delays. A constant delay of reinforcement (either 15 seconds or 30 seconds) composed one terminal link and mixed delays (.2 second and twice the value of the constant delay) were arranged in the other terminal link. The proportion of .2-second delays in the mixed-delay terminal link took on values of 0, .1, .25, .5, .75, .9, and 1.0 over experimental conditions. Based on relative rates of responding in the initial links, preference for the mixed delays was a negatively accelerated function of the proportion of short, mixed delays. Three of five rats preferred the mixed delays to the constant delays when the proportion of short, mixed delays was .1 or higher, and all five rats preferred the mixed delays when the proportion of short, mixed delays was .25 or higher. Neither Squires and Fantino's (1971) delay-reduction model of choice nor a model based on the harmonic mean reinforcement delay provided a close estimate of choice proportions over the range of short-delay proportions studied. The delay-reduction model underestimated choice for the mixed delays at low and intermediate proportions of short delays, and the harmonic-mean-delay model overestimated choice for the mixed delays at intermediate and high proportions of short delays.     

Hill-climbing by pigeons

Pigeons were exposed to two types of concurrent operant-reinforcement schedules in order to determine what choice rules determine behavior on these schedules. In the first set of experiments, concurrent variable-interval, variable-interval schedules, key-peck responses to either of two alternative schedules produced food reinforcement after a random time interval. The frequency of food-reinforcement availability for the two schedules was varied over different ranges for different birds. In the second series of experiments, concurrent variable-ratio, variable-interval schedules, key-peck responses to one schedule produced food reinforcement after a random time interval, whereas food reinforcement occurred for an alternative schedule only after a random number of responses. Results from both experiments showed that pigeons consistently follow a behavioral strategy in which the alternative schedule chosen at any time is the one which offers the highest momentary reinforcement probability (momentary maximizing). The quality of momentary maximizing was somewhat higher and more consistent when both alternative reinforcement schedules were time-based than when one schedule was time-based and the alternative response-count based. Previous attempts to provide evidence for the existence of momentary maximizing were shown to be based upon faulty assumptions about the behavior implied by momentary maximizing and resultant inappropriate measures of behavior.     

Duration-reduction of avoidance sessions as negative reinforcement

Five rats were exposed to a shock-postponement procedure in which responses on each of two levers initially had equivalent effects. After an initial training sequence that ensured at least some responding on each lever, an additional consequence was made conjointly operative on the previously less-preferred lever for each animal. Each response on this lever continued to postpone shock, but also reduced the session duration by one minute. The conjoint contingencies were operative until, through session-shortening responses and the passage of time, the session was scheduled to end in two minutes; during the final two minutes the session-shortening contingency was disabled while the shock-postponement contingency continued to be operative on both levers. When responding shifted to a predominance on the session-shortening lever, the conjoint contingency was shifted to the other lever; for four of the five rats this reversal was followed by two additional reversals. Two of the rats' responding showed clear, strong, and unambiguous sensitivity to the session-shortening contingency. The responding of two others was also systematically controlled by that contingency, but the effects were less clearcut. The fifth animal showed an initial shift when session-shortening was introduced, but its subsequent behavior proved insensitive to reversals of procedure. The results clearly indicate a sensitivity of behavior to events on a time scale quite distinct from that of immediate consequences. They also support an interpretation of avoidance sessions, considered in their entirety, as events whose contingent relationship to behavior can affect that behavior—even in the absence of stimuli that delineate those relationships. Finally, these results support an interpretation of aversively based conditioning within a broader context, analogous to the “open versus closed economy” interpretation of appetitively controlled behavior.