Differential acquisition of lever pressing in inbred and outbred mice: comparison of one-lever and two-lever procedures and correlation with differences in locomotor activity

Recent progress in mouse genetics has led to an increased interest in developing procedures for assessing mouse behavior, but relatively few of the behavioral procedures developed involve positively reinforced operant behavior. When operant methods are used, nose poking, not lever pressing, is the target response. In the current study differential acquisition of milk-reinforced lever pressing was observed in five inbred strains (C57BL/6J, DBA/2J, 129X1/SvJ, C3H/HeJ, and BALB/cJ) and one outbred stock (CD-1) of mice. Regardless of whether one or two levers (an "operative" and "inoperative" lever) were in the operant chamber, a concomitant variable-time fixed-ratio schedule of milk reinforcement established lever pressing in the majority of mice within two 120-min sessions. Substantial differences in lever pressing were observed across mice and between procedures. Adding an inoperative lever retarded acquisition in C57BL/6J, DBA/2J, 129X1/SvJ, and C3H/HeJ mice, but not in CD-1 and BALB/cJ mice. Locomotor activity was positively correlated with number of lever presses in both procedures. Analyses of durations of the subcomponents (e.g., time to move from hopper to lever) of operant behavior revealed further differences among the six types of mice. Together, the data suggest that appetitively reinforced lever pressing can be acquired rapidly in mice and that a combination of procedural, behavioral, and genetic variables contributes to this acquisition.     

Tests of an indifference rule in variable‐delay and double‐reward choice procedures with humans

Four hundred and fifty participants were recruited from Amazon Mechanical Turk across 3 experiments to test the predictions of a hyperbolic discounting equation in accounting for human choices involving variable delays or multiple rewards (Mazur, 1984, 1986). In Experiment 1, participants made hypothetical choices between 2 monetary alternatives, 1 consisting of a fixed delay and another consisting of 2 delays of equal probability (i.e., a variable‐delay procedure). In Experiment 2, participants made hypothetical monetary choices between a single, immediate reward and 2 rewards, 1 immediate and 1 delayed (i.e., a double‐reward procedure). Experiment 3 also used a double‐reward procedure, but with 2 delayed rewards. Participants in all 3 experiments also completed a standard delay‐discounting task. Finally, 3 reward amounts were tested in each type of task ($100, $1000, and $5000). In the double‐reward conditions (Experiments 2 and 3), the results were in good qualitative and quantitative agreement with Mazur's model (1984, 1986). In contrast, when participants made choices involving variable delays (Experiment 1), there was relatively poor qualitative and quantitative agreement with this model. These results, along with our previous findings, suggest the structure of questions in hypothetical tasks with humans can be a strong determinant of the choice pattern.     

The effects of delayed physical prompts and reinforcement on infant sign language acquisition

Researchers and clinicians have recommended that sign language be taught to typically developing children during their first 2 years of life; however, existing research does not provide adequate information regarding appropriate methods of sign training. We used delayed physical prompting and reinforcement to teach manual signs to 3 children between the ages of 6 and 13 months. Data were collected on the occurrence of prompted and independent signs as well as crying. Sign training was successful in producing independent signing in all 3 children in under 4 hr of training per child.     

The effects of antecedent interventions and extinction on toddlers' compliance during transitions

We compared the effects of two antecedent strategies commonly used in early childhood settings to increase compliance during activity transitions: a warning condition, in which children were informed of the transition 2 min before it began, and a condition in which children were allowed access to a toy during the transition. Both antecedent interventions were ineffective when implemented alone; however, when these strategies were combined with extinction, improvements in compliance were observed for all children.     

Functional analysis of self‐injury maintained by automatic reinforcement: exposing masked social functions

Two functional analyses for self‐injurious behavior (SIB) exhibited by a child diagnosed with mental retardation and autism were conducted. Responding was high and undifferentiated in the first functional analysis, indicating that SIB was maintained by automatic reinforcement. During the second functional analysis, the client wore a padded helmet and all SIB was blocked. SIB decreased in all conditions except attention, suggesting that SIB was multiply controlled (social positive and automatic reinforcement). Copyright © 2001 John Wiley & Sons, Ltd.     

Training student teachers to reposition infants frequently

We evaluated the effects of an intervention designed to increase the variety of positions experienced by infants in a child-care setting. Six student teachers were trained, using a multicomponent intervention, to reposition infants according to a chart. The intervention was successful in increasing the mean percentage of correct position changes made by all 6 student teachers, and performance gains by 3 student teachers persisted when supervisor feedback was briefly removed.     

A Quantitative Analysis and Natural History of B. F. Skinner's Coauthoring Practices

This paper describes and analyzes B. F. Skinner's coauthoring practices. After identifying his 35 coauthored publications and 27 coauthors, we analyze his coauthored works by their form (e.g., journal articles) and kind (e.g., empirical); identify the journals in which he published and their type (e.g., data-type); describe his overall and local rates of publishing with his coauthors (e.g., noting breaks in the latter); and compare his coauthoring practices with his single-authoring practices (e.g., form, kind, journal type) and with those in the scientometric literature (e.g., majority of coauthored publications are empirical). We address these findings in the context of describing the natural history of Skinner's coauthoring practices. Finally, we describe some limitations in our methods and offer suggestions for future research.     

A descriptive analysis of potential reinforcement contingencies in the preschool classroom

In recent years, functional analysis methods have been extended to classroom settings; however, research has not evaluated the extent to which consequences presented during functional analysis are associated with problem behavior under naturalistic classroom conditions. Therefore, the purpose of this study was to determine whether the social consequences commonly manipulated in functional analyses occur in typical preschool classrooms. A total of 14 children attending preschool programs participated in the study. Data were collected on the occurrence of antecedent events (e.g., presentation of tasks), child behaviors (e.g., aggression), and teacher responses (e.g., delivery of attention). The probability of various teacher responses given child behavior was then calculated and compared to the response-independent probabilities of teacher responses. Attention was found to be the most common classroom consequence (100% of children), followed by material presentation (79% of children), and escape from instructional tasks (33% of children). Comparisons of conditional and response-independent probabilities showed that the probability of teacher attention increased given the occurrence of problem behavior for all children, suggesting that a contingency existed between these two events. Results suggest that functional analyses that test the effects of attention, escape, and access to materials on problem behavior may be appropriate for preschool settings.     

Effects of reward magnitude frames on measures of delay discounting in a hypothetical money scenario

The current study analyzed the effects of three frames of reward magnitude—quantity, volume, and duration—on the rate at which college students discounted hypothetical, delayed monetary rewards. Hypothetical scenarios were presented using the fill-in-the-blank discounting questionnaire and participants made choices between immediate and delayed hypothetical monetary rewards. Scenarios framed the monetary choices as (a) quantity of dollar bills, (b) height (inches) of a stack of dollar bills, and (c) duration of time spent in a hypothetical cash machine to collect dollar bills. For each scenario, participants' subjective values were used to calculate the area under the curve (AuC). Framing resulted in a moderate effect size: The duration frame yielded significantly smaller AuC values compared to the quantity and volume frames. Thus, the framing of reward magnitude was a significant variable in controlling discounting rates for hypothetical, delayed monetary rewards. Subsequent investigations should be aware of the independent effects of the reward magnitude frames on delay discounting rates.     

Functional analysis and treatment of breath holding maintained by nonsocial reinforcement.

A functional analysis showed that breath holding exhibited by a 16‐year‐old boy with mental retardation occurred independent of social consequences. Assessment results of the existing treatment procedure—a verbal reprimand—were used to design a treatment package that reduced the behavior to low levels across 7 months.