Reinforcement magnitude and the inhibiting effect of reinforcement

In a two-key concurrent variable-interval schedule (using pigeons), if the reinforcement frequency for one response is held constant while that for the other is increased, the rate of response on the constant key decreases. The immediate reinforcement for key pecking can usually be conceptualized as the change from a condition in which the key light is on and the food hopper light is off to one in which the key light is off and the hopper light is on. The prechange condition is associated with a delay to food of one-half the average interreinforcement interval in effect during this condition. The postchange condition is associated with a delay to food of about .5 seconds. The programming of additional reinforcement results in a decrease in the delay to food associated with the prechange stimulus condition, and thus a decrease in the value of the improvement that results from the change. This would appear to be analogous to a decrease in the amount of reinforcement, and thus sufficient explanation for the decrease in the rate of the response.     

Reducing residential electrical energy use: payments, information, and feedback

Monetary payments, energy information, and daily feedback on consumption were employed to reduce electricity use in four units of a university student housing complex. A combined multiple-baseline and withdrawal design permitted both within- and between-unit comparisons. Payments produced immediate and substantial reductions in consumption in all units, even when the magnitude of the payments was reduced considerably. Feedback also produced reductions, but information about ways to conserve and about the cost of using various appliances did not. It was also found that, in general, payments combined with either information or feedback produced no greater effect than payments alone.     

Time-series analysis in operant research

A time-series method is presented, nontechnically, for analysis of data generated in individual-subject operant studies, and is recommended as a supplement to visual analysis of behavior change in reversal or multiple-baseline experiments. The method can be used to identify three kinds of statistically significant behavior change: (a) changes in score levels from one experimental phase to another, (b) reliable upward or downward trends in scores, and (c) changes in trends between phases. The detection of, and reliance on, serial dependency (autocorrelation among temporally adjacent scores) in individual-subject behavioral scores is emphasized. Examples of published data from the operant literature are used to illustrate the time-series method.     

EFFECTS OF DIRECT,INTERMITTENT, AND VICARIOUS REINFORCEMENT PROCEDURES ON THE DEVELOPMENT AND MAINTENANCE OF INSTRUCTION-FOLLOWING BEHAVIORS IN A GROUP OF YOUNG CHILDREN1

A group of young children (mean age: 2.5 yr) were instructed to follow different requests by a teacher in a day-care setting. Experiment I verified that mean group instruction following was low (10%) despite the opportunity for “observational learning”, i.e., the group of 12 children could watch a nonreinforced adult comply with the teacher's request. In Experiment II, when positive consequences were provided contingent on the adult model's behavior, mean group instruction following was relatively unaffected (14%). When direct reinforcement was given to four peer models, each for several sessions, the individual performances of three of the four peer models was elevated (from 50% to 80%); however, the mean performance of the remaining nonreinforced children (N = 7) was only moderately affected (21%). When reinforcement contingencies were again changed, so that each group member was provided direct, but intermittent reinforcement, mean group performance increased substantially to levels of over 70%. Once instruction following was high, presentation of reinforcement only to one peer model sufficed to maintain performance whereas earlier, this same vicarious reinforcement procedure had failed to establish group compliance. The maintenance of instruction-following behavior when reinforcement was applied solely to one child was interpreted mainly in terms of a high resistance to extinction following a history of intermittent reinforcement rather than a “vicarious”- or “self”-reinforcement mechanism. Finally, removal and re-introduction of group intermittent reinforcement, respectively, lowered performance (to levels of 40%) and elevated (to levels of 65%) the group's performance.     

SOCIAL-SKILLS TRAINING FOR UNASSERTIVE CHILDREN: A MULTIPLE-BASELINE ANALYSIS1

The effects of social-skills training consisting of instructions, feedback, behavior rehearsal, and modelling were examined in a multiple-baseline analysis in four unassertive children. The treatment was effective in that the behaviors selected for modification changed markedly. The effects of treatment generalized from trained to untrained items (interpersonal situations requiring assertive responding) and gains were maintained at the two- and four-week followup probe sessions. In addition, overall assertiveness in all subjects increased from baseline assessment to the conclusion of treatment and into followup.     

TEACHING COIN EQUIVALENCE TO THE MENTALLY RETARDED1

A program was designed to teach coin equivalence to mentally retarded adolescents. Coin equivalence was defined as choosing several different combinations of coins to equal specified target values. A pretest-posttest matched-groups design was employed with an experimental group receiving the monetary training, and a no-training control group. A multiple baseline across coin-counting responses was also incorporated in the experimental group. Training was divided into six stages, each teaching one specific method of combining coins to equal 10 target values from 5¢ through 50¢. A three-component response chain was used, requiring (a) naming, (b) selecting and counting, and (c) depositing target monetary values into a coin machine. Experimental subjects improved significantly in coin equivalence performance and maintained their skill on follow up tests; control subjects did not.     

Control of responding by location of auditory stimuli: adjacency of sound and response.

Four rhesus monkeys were trained to respond on one key when a one-second noise burst was presented through one speaker and to respond on a second key when the noise burst was presented through a second speaker. The acquisition of stimulus control was studied under three conditions, in each of which the relationship between the sound source and the response-key positions varied: an adjacent condition in which the noise burst was presented through the key and a response on this key was reinforced; a reversed-adjacent condition in which the noise burst was presented through one key and responding on the other key was reinforced: and a nonadiacent condition in which responding on the key nearer the sound was reinforced. Under adjacent conditions, stimulus control developed within one or two sessions. Under reversed and nonadjacent conditions, 10 sessions were required for the development of control. The asymptote of correct responding was the same under each condition in all animals.     

Control of pigeons' pecking by trace stimuli

In Experiment I, pigeons' pecking a white key was reinforced with grain when white was immediately preceded by a vertical white line on a green surround, but not by green alone. This procedure produced control of pecking by the line. Next, pecking white was reinforced after vertical line on green, but not after green alone or other orientations of the white line on green. The line-tilt dimension initially did not control pecking, a result that showed that interdimensional (line versus no line) training does not always result in dimensional control. Line-tilt control was eventually established but was accompanied by a decrease in interdimensional control. In Experiment II, interdimensional training, with or without a trace interval intervening between line on green or green alone and white, was followed by tests for line-tilt control. While interdimensional control was unaffected by the trace interval, line-tilt control tended to be less with the trace interval. This dissociation of interdimensional and dimensional control, as well as the failure of interdimensional training to produce dimensional control in Experiment I, suggests that the line stimulus is multidimensional.     

Positive contrast, negative induction, and inhibitory stimulus control in the rat

In Experiment I, 24 rats were trained on a multiple variable-interval variable-interval schedule with a doorlight and white noise serving as component cues. Two groups were then shifted to a multiple extinction variable-interval schedule, and a third group was maintained on the multiple variable-interval variable-interval schedule. The multiple extinction variable-interval condition produced positive contrast when either the light or noise signalled extinction, and both of these cues acquired inhibitory stimulus control as measured by a combined cue test. In Experiment II, the multiple variable-interval variable-interval condition was shifted to multiple extinction variable-interval for one group, to multiple variable-time variable-interval for a second group, and was unchanged for the third group. The two experimental conditions produced identical patterns of response-rate reduction in the altered component, but the multiple extinction variable-interval condition produced positive contrast, whereas the multiple variable-time variable-interval condition did not. Subsequent combined cue and resistance to reinforcement tests revealed that the cue signalling extinction acquired stronger inhibitory stimulus control than the cue signalling variable time.     

Signalled free-operant avoidance of shock by pigeons pecking a key

Two pigeons were trained to peck a key under a free-operant avoidance schedule. Then, changes in key color signalled the beginning (safe period) and the end (warning period) of the response-shock interval, with a response required to change the key color. Finally, a change in key color signalled the warning period and either a response or a shock reinstated the safe stimulus. During signalled avoidance, response rate was higher during the warning stimulus than during the safe stimulus. More responding tended to occur in the warning stimulus when it was terminated by either a response or a shock than by only a response. In either procedure, response latency during the warning stimulus was a function of the duration of the warning stimulus. In general, response and shock rate were higher during unsignalled than during signalled avoidance. When the warning stimulus was brief, the results were similar to those of unsignalled avoidance. These results confirm previous findings with pigeons, are in general agreement with data provided by other species in studies of signalled avoidance, and thereby indicate the transituationality of the key-pecking operant.