Persistent behavior maintained by unavoidable shocks

Squirrel monkeys were trained on a multiple schedule in which 10-min periods on a continuous shock avoidance schedule, indicated by a yellow light, alternated with 10-min periods on a 1.5-min variable interval schedule of food reinforcement (VI 1.5). A white light indicated that VI 1.5 was in effect, except for the middle 2 min of the period on VI 1.5, in which a blue light appeared and terminated with the delivery of a 0.5-sec unavoidable shock. Stable response rates developed in the avoidance and VI 1.5 components. However, the highest response rates occurred in the blue, preshock stimulus. A series of experiments showed that responding in the blue stimulus persisted even when responding had been extinguished on both the VI schedule of food reinforcement and the shock avoidance schedule. Responding in the blue stimulus ceased when the blue stimulus terminated without shock or when it terminated with a response-contingent shock. Each time responding ceased, it was restored by terminating the blue stimulus with an unavoidable shock. When the blue stimulus was on throughout each session and unavoidable shocks were delivered at regular 10-min intervals, responding was well maintained. These results show that in monkeys that have been trained on a continuous avoidance schedule, unavoidable shocks can maintain responding even under conditions where responses have no programmed consequences.     

Conditioned reinforcement in second-order schedules

Pigeons responded under a schedule in which food was presented only after a fixed number of fixed-interval components were completed. Two such second-order schedules were studied: under one, 30 consecutive 2-min fixed-interval components were required; under the other, 15 consecutive 4-min fixed-interval components were required. Under both schedules, when a 0.7-sec stimulus light was presented at completion of each fixed interval, positively accelerated responding developed in each component. When no stimulus change occurred at completion of each fixed interval, relatively low and constant rates of responding prevailed in each component; a similar result was obtained when a 0.7-sec stimulus change occurred at completion of each fixed interval except the one which terminated with primary reinforcement. The 0.7-sec stimulus correlated with food delivery was an effective conditioned reinforcer in maintaining patterns of responding in fixed-interval components despite low average frequencies of food reinforcement.     

Fixed-interval responding under second-order schedules of food presentation or cocaine injection.

Squirrel monkeys operated a key under second-order schedules in which every tenth completion of a 5-minute fixed interval resulted in either presentation of food or intravenous injection of cocaine. When a 2-second light was presented at the completion of the component fixed-interval schedules, positively accelerated responding developed and was maintained in each component. Over a tenfold range of doses of cocaine(30 to 300 microgram/kg/injection) and amounts of food (0.75 to 7.5 g/presentation); the second-order schedule of cocaine injection maintained higher average rates of responding than the second-order schedule of food presentation. Substituting saline for cocaine or eliminating food presentation decreased average rates of responding. When no stimulus change occurred at the completion of the first nine component fixed-interval schedules, but the 2-second light and food presentation or cocaine injection still occurred after the tenth component, only low and relatively constant rates of responding were maintained in each component. Patterns of responding characteristic of 5-minute fixed-interval schedules were maintained by the 2-second light paired with either cocaine injection or food presentation, though the maximum frequency of cocaine injection or food presentation was less than once per 50 minutes.     

Lorenz Curves: A New Model for the Distribution of Psychiatric Services

The growth of child and adolescent psychiatric services based on the wraparound philosophy raises new questions for medical directors, investigators, and clinicians interested in improving quality of care and outcomes. Typically, quality improvement studies have focused on standardizing care and decreasing variation while community based services following a wraparound model are by definition individualized. To date, little information on how to evaluate such services in a managed care environment has been available. We present one option for evaluating the distribution of medical services and the extent to which providers individualize services for children with severe emotional disorders. Specifically, we (a) review the philosophy and goals of wraparound services, (b) introduce the Lorenz curve as a tool for determining the degree of inequality in service distribution at a given institution, and (c) present a case study on the use of Lorenz curves by a Medicaid Behavioral Health Organization in profiling behavioral providers.     

Deliberate Self-Poisoning,Unemployment, and Public Health

The purpose of the present investigation was to explore further the known relationship between deliberate self-poisoning and social deprivation. Each individual who attended one of Cork city's three casualty departments following an act of deliberate self-poisoning in 1988 was examined. The place of residence (ward) of each city resident patient was established. The social status of the city's 34 wards was estimated using a number of indices obtained from the 1981 and 1986 census reports and social service records. A comparison was made between the 1988 self-poisoning rate for each ward and the rate found in a 1982 study of the city. Correlations between self-poisoning rate and seven social deprivation indices were found to be significant. Multiple regression, factor, and partial correlation analyses were carried out to examine more closely the interrelationships between the social deprivation indices. With respect to explaining the variation in the self-poisoning rate, unemployment alone performed almost as well as all of the indices together and as well as the factors derived using factor analysis. The correlation between unemployment and self-poisoning rate remained highly significant when the other related variables were controlled for. However, at fixed levels of unemployment, these variables were found to be independent of the self-poisoning rate. It is suggested that whereas clinical intervention may benefit the individual, deliberate self-poisoning as an issue requires a public health approach for its resolution.