Eliminating selective stimulus control: a comparison of two procedures for teaching mentally retarded children to respond to compound stimuli

Selective stimulus control occurs when behavior fails to come under control of all characteristics of a compound stimulus after discrimination training. Two different assessment procedures, one used in prior research and the other incorporating incorrect stimuli (S - 's) which differed minimally from the correct stimulus (S+), were used to detect stimulus control deficits characteristic of selective stimulus control. The efficacy of two training procedures in eliminating selective stimulus control observed with three trainable mentally retarded children was evaluated in Experiment 1. A training procedure using S - 's that were minimally different from the S+ was designed to reduce the probability that stimulus discriminations could be based on stimulus characteristics other than experimenter-specified characteristics defining the S+. This procedure proved more effective in preventing and eliminating selective stimulus control as measured by both assessment procedures than an alternate discrimination training procedure that failed to impact the more stringent measures of selective stimulus control. Experiment 2 indicated that these improvements in stimulus control were not a function of varying degrees of difficulty between stimulus sets or of a prior history of discrimination training with the less effective training procedure. The need for better assessment procedures to detect selective stimulus control and suggestions for further improvements in discrimination training procedures are discussed.     

Quasireinforcement: Control of behavior by second-order interval schedules

Pigeons were trained on a variable-interval 66-sec schedule of reinforcement that was segmented into either fixed- or variable-interval 10-sec components. Three-second access to food followed some components according to the overall VI 66-sec schedule, but 3-sec periods of nonreinforcement followed the other components. With both FI 10-sec and VI 10-sec segments, overall response rates were generally higher when the completion of unreinforced segments was signaled by a red key (never paired with food) than when it was unsignaled. Response rates during the red-key periods dropped to zero. Brief presentations of the red key engendered the distinctive (FI or VI) patterns of responding which would be expected if each segment were followed by food. These data demonstrate behavioral control by brief stimuli which are not paired with primary reinforcement and show that such control may develop even when the sequences of behavior required to produce food or brief stimuli are variable in duration.     

Stimulus control of responding by response-reinforcer temporal contiguity

The stimulus properties of brief disruptions in response-reinforcer temporal contiguity were investigated using a discrete trial conditional discrimination procedure. Key pecking (nondelay) or key pecking followed by a brief interval of nonpecking (delay) in the sample component produced a stimulus change (choice component). Pecks in the choice component to one of two alternatives resulted in food or blackout, conditional upon which response requirement was met in producing the choice component. A baseline condition, in which key pecking always produced the choice component and correct choices were arranged randomly, alternated with experimental conditions that included nondelay and delay values of either 0.2, 0.5, or 1.0 sec between the last key peck and the initiation of the choice component. All subjects accurately discriminated brief temporal delays between a response and stimulus change, with choice accuracy increasing for three of four subjects as the temporal disruption in contiguity increase. Implications of the research for the study of delayed reinforcement, response-independent reinforcement, and the discrimination of causality are discussed.     

Intertrial interval effects on internal stimulus control of behavior in brightness differential conditioning

In Experiment 1, groups were given a trial sequence in differential conditioning in which all S+ trials preceded all S? trials (+? schedule) or one in which some S+ trials followed S? trials (+?+ schedule) and either a 1- or a 30-min intertrial interval (ITI). ITI affected discrimination learning only in the +? schedule condition; schedule affected discrimination only at massed trials. In Experiment.2, all groups received a +?+ schedule. In two groups, given a 1- or 15-min ITI between all trials, discrimination learning was independent of ITI. Discrimination learning was facilitated in two other groups given a 1-min ITI between all trials except between S? and the subsequent S+ trial, when the ITI was either 15 or 60 min. The results were discussed in terms of their implications for internal reward-related stimulus control of behavior in differential conditioning.     

A study of some conditions relating to the retarded adult's stereotyped responding in a binary-choice task

This study was a longitudinal one that examined the effects of certain conditions on alternation and perseveration in a binary-choice task. The conditions manipulated included: (1) lapse of time (stability of the pattern), (2) stimulus dissimilarity, (3) spatial location of the two alternatives, (4) time-out (time away from the task), (5) delay between responses, and (6) differential reinforcement of the two choices. Eight mentally retarded adults, identified as “pure” alternaters or perseveraters, served as subjects. Perseveration was “disrupted” only by differential reinforcement. Alternation was affected by all experimental manipulations with the exception of stimulus dissimilarity.     

Delayed matching in the pigeon: Effect on performance of sample-specific observing responses and differential delay behavior

Pigeons were trained on a delayed matching-to-sample task with a 0-sec delay and then transferred to a 1-sec delay (Experiment 1) or were trained with mixed 0-sec/1-sec delays and then transferred to longer mixed delays up to 28 sec (Experiment 2). Four groups were distinguished by the nature of the observing response required to each sample color (red and blue). For Group NN pecks were allowed to neither color. For Group PcPc pecks were required to both colors. For Group PcN pecks were required to red but were not allowed to blue. For Group PcPt pecks were required at the center key in the presence of red, but at a key located directly above the center key in the presence of blue. The results of both experiments indicated significant effects of both Pecking vs Not Pecking, and Sample-Specific vs Sample-Independent Responding. At the longer delays individual differences in sample-specific delay behavior were a better predictor of performance than the behavior required in the presence of the sample.     

The relationship of moral judgment, self-awareness, and sex to complicance behavior

Sixty male and sixty female college students, representing three of Kohlberg's stages of moral judgment, were exposed to a complicance situation in which their personal count of a series of metronome clicks was contradicted by a unanimous group. Group differences were either one or two steps from veridical. For half of the subjects self-awareness was experimentally increased. The results indicated that subjects in moral judgment Stages 3 and 4 complied significantly more than Stage 5 subjects. The self-awareness manipulation produced a complex pattern of results in the form of a three way interaction with moral judgment and type of compliance. Finally, sex differences in compliance behavior were significant, with females complying more than males. The results were discussed in terms of a cognition-behavior relationship.     

On the formation of personal space and self-boundary structures in early human development: The case of infant stranger reactivity

Personal space and self-boundary are, respectively, sociological and intra-psychological concepts that refer to a complex of behavioral and subjective events between and within individuals. While there are large bodies of literature concerned with each of these concepts, literature that cuts across many disciplines of study, there has never been an integration of these concepts around specific human developmental issues. The present article focuses upon human infancy as a period in which both personal space and self-boundary phenomena can be observed. Developmental links between personal space and self-boundary phenomena in infancy and adulthood are outlined and discussed.     

Social control by adult preference in operant conditioning with children

During daily sessions four institutionalized retardates and four normal, first-grade children each played a two-choice marble dropping game while an adult experimenter sat beside and watched. When one of two colored lights was presented, two tokens were dispensed as soon as the subject dropped a marble, and when the other light was on, one token was dispensed. During choice trials that were interspersed among single-colored trials the subject was required to choose one of the two different colored holes. After the subject developed a preference for the color that earned two tokens, the experimenter stated a preference for the response that earned only one token (i.e., “I like it better when you put it into the —colored hole.”) Six of the eight subjects immediately switched to the response that earned low magnitude reinforcement when the experimenter stated his preference. Only two subjects switched back to the response that earned high magnitude reinforcement when the experimenter left the room. Subjects complied with the experimenter's preference statement regardless of whether or not it also included a negative component (i.e., what the experimenter did not like). There were no systematic differences between mentally retarded and normal subjects.     

Response discriminative and reinforcement factors in stimulus control of performance on multiple and chained schedules of reinforcement

Discriminative control of the response rates of two groups of rats was equated by training them to cease bar pressing in light-out no-tone ( + ) and to respond during tone and light. Multiple-schedule subjects received food at the same rate for responding during tone or light as for nonresponding in + . For the chained-schedule subjects responding in tone or light only produced + where food was received for nonresponding. In extinction tests multiple-schedule subjects emitted approximately twice the responses to tone-plus-light as to tone or light presented individually (additive summation). The rats trained on the chained schedule, in which the tone and light each controlled substantial response rates but were never paired with food, showed no summation when the tone and light were presented together. The results indicate that discriminative control of response rates and reinforcement differences between schedule components determine stimulus control.     

Recognition memory in mentally retarded persons

The continuous recognition memory of retarded and normal subjects was assessed. The stimuli were magazine pictures, arranged so that lags of up to 250 pictures occured. The overall performance of the retarded subjects was poorer, in terms of hit rate or d′. However, the differences were present at 0 lag and the slopes of the forgetting curves were similar in both groups. It was concluded that differences between these subjects were due to a perception related process and not to memory.