Selective reinforcement of schizophrenics' interview responses

In this experiment each of five examiners tested and interviewed four subjects in each of three conditions. The subjects were 60 male, hospitalized schizophrenics. The three conditions were the reinforcement, after an operant period, of “sick talk”, “healthy talk”, or plural nouns during a structured interview. Half the Welsh factor A and R scale items were administered before the interview, half after the interview. Significant differences were found among experimental conditions in terms of changes from operant to reinforced interview periods in percentage of “sick talk” emitted by subjects and changes from pre- to post-testing in terms of Welsh R scores. The correlation between these two measures of change was statistically significant. The results were discussed in terms of the different therapeutic strategies of neoanalytic and behaviour therapists.     

Effects of reinforcement history on response rate and response pattern in periodic reinforcement

Several researchers have suggested that conditioning history may have long-term effects on fixed-interval performances of rats. To test this idea and to identify possible factors involved in temporal control development, groups of rats initially were exposed to different reinforcement schedules: continuous, fixed-time, and random-interval. Afterwards, half of the rats in each group were studied on a fixed-interval 30-s schedule of reinforcement and the other half on a fixed-interval 90-s schedule of reinforcement. No evidence of long-term effects attributable to conditioning history on either response output or response patterning was found; history effects were transitory. Different tendencies in trajectory across sessions were observed for measures of early and late responding within the interreinforcer interval, suggesting that temporal control is the result of two separate processes: one involved in response output and the other in time allocation of responding and not responding.     

Self-control in children with autism: response allocation during delays to reinforcement.

This study examined the use of a progressive‐delay schedule of reinforcement to increase self‐control and decrease disruptive behavior in children with autism. When initially given the choice between an immediate smaller reinforcer and a larger delayed reinforcer, all participants chose the smaller reinforcer. When access to the larger reinforcer required either no activity or engaging in a concurrent task during the delay, all participants demonstrated both self‐control and preference for a response requirement. Disruptive behavior decreased during delays that required a concurrent task compared to sessions without an activity requirement.     

Effects of choice and immediacy of reinforcement on single response and switching behavior of children

Children responded on a single operandum to produce marbles or candy within a two-component multiple schedule and then were allowed to choose which component was in effect. Experiment I examined the effects of exchanging marbles after sessions for subject-selected or experimenter-selected candy. Rate of response to the single operandum was not affected. However, when the subjects could switch components, they spent the majority of time and responded at somewhat higher rates in a component where marbles were exchangable for subject-selected candy. Experiment II examined the effects of eliminating the immediate marble consequence for responses. Rate of response to the single operandum was not affected. However, when subjects could switch components they spent more time in a component where immediate marble consequences were available for responses, than where no immediate marble consequences were available.     

Conditioned reinforcement and response strength

Stimuli associated with primary reinforcers appear themselves to acquire the capacity to strengthen behavior. This paper reviews research on the strengthening effects of conditioned reinforcers within the context of contemporary quantitative choice theories and behavioral momentum theory. Based partially on the finding that variations in parameters of conditioned reinforcement appear not to affect response strength as measured by resistance to change, long-standing assertions that conditioned reinforcers do not strengthen behavior in a reinforcement-like fashion are considered. A signposts or means-to-an-end account is explored and appears to provide a plausible alternative interpretation of the effects of stimuli associated with primary reinforcers. Related suggestions that primary reinforcers also might not have their effects via a strengthening process are explored and found to be worthy of serious consideration.     

Intermittent reinforcement of a continuous response

Konorski showed that when a go/no-go procedure was used, sound quality discriminations were rapidly acquired and sound location discriminations were slowly acquired. These findings have been interpreted as a general constraint on the acquisition of auditory discriminations (quality-location effect). However, experiments carried out within an evolutionary framework (Harrison, 1984) have shown that the rate of acquisition of sound location discriminations varies widely as a function of the inclusion or exclusion of naturalistic features. These data suggest that Konorski's findings were a function of the special conditions of the experiments. The first purpose of the present experiments was to assess whether rats showed the effects noted by Konorski when studied under similar conditions. The second purpose was to study the effect of manipulating two natural features (novelty and stimulus-response adjacency) to assess whether the acquisition rates of quality and location discriminations could be greatly modified or made approximately equal, or both. When a go/no-go procedure was used and the other conditions were similar to those of Konorski, rats acquired a quality discrimination but did not acquire a location discrimination. However, when the S+ or S- were presented through a closely adjacent speaker, the sound location discrimination was acquired as rapidly as the quality discrimination. Finally, preexposing the animal to either S+ or S- retarded the rate of or prevented the acquisition of the quality discrimination. The experiments showed that the quality-location effect was determined primarily by the conditions used in Konorski's experiments, and that the effect is not a general constraint on learning.     

Selective punishment early and late in fixed-ratio schedules of food reinforcement

Pigeons key pecked for grain on a fixed-ratio 100 schedule; electric shocks occurred intermittently at the fifteenth or eighty-fifth response in the ratio. In Experiment I, shock was at the fifteenth response for two birds, and at the eighty-fifth response for two others, in every sixth, twelfth, or eighteenth ratio. Rate of responding decreased as frequency of shock increased, and the pattern of responding included an increased initial pause and low rates or pause-run sequences that extended further into the ratio when shock was at the fifteenth response than when it was at the eighty-fifth response. Shock early in the ratio engendered longer initial pauses than shock late in the ratio. In Experiment II, four birds responded on a two-component multiple schedule in which shock occurred at the fifteenth response of the third ratio in the presence of a white keylight and at the eighty-fifth response of the third ratio in the presence of a green keylight. The overall rates of responding decreased as shock intensity increased. All four birds responded differentially to the white and green keylights, but with a pattern that varied between birds. In general, punishment reduced the probability of responses that preceded it, regardless of the ordinal position of those responses. Both studies confirm that the probability of responding is reduced less by aversive stimuli produced late in a fixed-ratio than by aversive stimuli produced early in a fixed-ratio.     

An examination of vicarious reinforcement processes in children

The primary purpose of the present investigation was to examine vicarious reinforcement processes in children. More specifically, the effects on one child of observing another same-sex child receive direct reinforcement were explored across three different age levels. Subjects were 216 children, randomly assigned to experimental or control conditions. For the control condition, neither child in the same-sex, same-age dyad received reinforcement for performance on the experimental task. For the experimental condition, one child in each dyad received direct social reinforcement for performance, while the other child received no social reinforcement for similar performance. Although children who observed other children receive direct social reinforcement initially increased performance (as predicted by vicarious reinforcement hypotheses), their performance soon decreased and was characterized by verbal and nonverbal responses which appeared to interfere with task performance (e.g., “Hey, I can do them too”, “Look at mine”, “There's no use in trying”). It appeared as if these observing children were being punished for their performance. Such effects were more pronounced for older than younger children; however, they were observed equally in boys and girls. Results were discussed in terms of vicarious reinforcement and “implicit punishment” hypotheses. Implications for applied settings were also addressed.     

Differential reinforcement of interresponse times with controlled probability of reinforcement per response

Pigeons were presented food after interresponse times (IRTs) longer or shorter than a fixed percentage of their most recent IRTs. This procedure controlled probability of reinforcement per response while still allowing different classes of IRTs to be reinforced differentially. Support was found for IRT-reinforcement theory in that response rates were determined by the degree and direction of differential reinforcement of IRTs, but were relatively independent of probability of reinforcement per response and of the length of the control system's IRT memory. Stimulus control of these differential response rates was also demonstrated.     

Behavioral contrast and response independent reinforcement

Four pigeons received pre-training that included presentation of the reinforcer independently of behavior and then baseline training on a variable-interval schedule of reinforcement. With the introduction of a multiple schedule, in which the first stimulus was associated with a response contingent and a second stimulus with a response independent, 1-min variable-interval schedule, a reduction in response rate was obtained in the second component, which was not accompanied by a behavioral contrast effect in the first component. A further three pigeons were given the same pre-training and baseline training before the introduction of an otherwise identical multiple schedule, in which no reinforcement occured in the second component. Behavioral contrast was obtained from all three subjects. The results indicated that under conditions of constant reinforcement density a reduction in responding is not a sufficient condition for the occurrence of behavioral contrast.