A comparison of the effects of partial reinforcement schedules using a within-subject serial autoshaping procedure

Three experiments, each using a single group of pigeons, are reported. In Experiment 1 subjects were initially trained with two stimuli, one of which was always followed by food, the other being reinforced according to a 50% partial reinforcement schedule. Subsequently a serial procedure was adopted in which an additional stimulus, C, was consistently followed by the partially reinforced CS. A second additional stimulus, A, was followed on half of its occurrences by the continuously reinforced CS, its remaining presentations being followed by nothing. The rate of autoshaped keypecking was substantially greater during A than during C. In the remaining experiments subjects received first-order conditioning with a single stimulus that was either partially (Experiment 2) or continuously (Experiment 3) reinforced. The stimuli A and C were then again introduced for serial autoshaping. Stimulus A was occasionally paired with the CS and occasionally followed by nothing, whereas stimulus C was always followed by the CS. As in Experiment 1, the rate of responding during A was greater than during C. It is proposed that one influence on the rate of autoshaped keypecking during a CS is the accuracy with which the immediate consequences of that CS are predicted.     

CLINICAL BEHAVIORAL PHARMACOLOGY: METHODS FOR EVALUATING MEDICATIONS AND CONTINGENCY MANAGEMENT

We evaluated methods for comparing the effects of dextroamphetamine (Dexedrine), thioridazine (Mellaril), and contingency management in the control of severe behavior problems. A reversal design was used in which medications were systematically titrated and assessed in unstructured as well as structured settings with three clients. Subsequently, behavioral procedures including timeout, differential reinforcement of other behavior, and visual screening, were used in a multiple-baseline design across settings. The assessment and design methods were useful in comparing the interventions. Dextroamphetamine decreased inappropriate behaviors and improved academic behaviors in one client, but no reliable effects were observed in the other two clients. Thioridazine was variable across clients, settings, behaviors, and dosages. Contingency management produced consistent decreases in inappropriate behaviors and small improvements in academic performance.     

Parents' teaching strategies with their children: The effects of parental and child status variables

The intent of the study was to examine the effects of parental (mother and father) and child (gender and communicative status) status variables on the teaching strategies used by parents in a paper-folding task. The linguistic and nonverbal strategies of 120 parent-child groupings were analyzed during paper-folding tasks. Parents' strategies were coded according cognitive demand and directiveness. Results indicated that strategies varied as a function of children's communicative status. Parents were less directive and more demanding of nonhandicapped children compared to handicapped children. Parents' strategies seemed to be determined by children's ability to sustain discourse. Results are discussed in terms of Vygotsky's notion of the zone of proximal development.This research was partially supported by a grant from the U.S. Office of Education, Office of Special Education (Grant No. G007902000) to I. Sigel and A. McGillicuddy-DeLisi at Educational Testing Service, Princeton, and from the Biomedical Research Support Grant Program, Division of Research Resources, N.I.H. (Grant No. BRSG 507RR07025-17) to the first two authors. We acknowledge the helpful comments of two anonymous reviewers.