Stimulus Control of Respondent and Operant Key Pecking: A Single Key Procedure

Abstract

Pigeons' responses to a uniformly illuminated response key were either reinforced on a variable-interval one-minute schedule of reinforcement or extinguished for one-minute periods. When 1.5 second signals were presented at the beginning of each compornent, so as to differentially predict reinforcement, the pigeons pecked at the signals, at rates higher than rates during the remainder of the component. When the brief signals were not differentially predictive of reinforcement, pecking in their presence decreased to near zero levels. Similar results were obtained with signals based upon colors and upon line orientations. Changes in rates of (unreinforced) pecking occurred during the signal whether pigeons responded differentially during the remainder of the component or not. Experiment II demonstrated that the presence of the signal correlated with extinction was not necessary for pecking to develop at the signal which preceded the component in which responding was intermittently reinforced. The experiments demonstrated a clear dissociation of respondent control from operant control of a response. In addition, operant behavior was shown to be relatively insensitive to differing rates of reinforcement, as compared to the sensitivity of respondent behavior to differing rates of reinforcement produced by the very same operant behavior.Key words: elicited and operant responding, stimulus control, trace stimuli, mixed schedules, key peck, pigeons Considerable evidence has accumulated which suggests that the stimuli associated with the various components of a multiple schedule have an eliciting, as well as a discriminative function (Gamzu & Schwartz, 1973;Gamzu & Williams, 1973;Ricci, 1973;Schwartz, 1973). The alternation of two stimuli which are differentially predictive of food appears to be a sufficient condition for the development of elicited pecking directed at the stimulus correlated with the higher frequency of reinforcement.The recognition of stimulus-reinforcer dependencies in multiple schedules of reinforcement led to the development of the additivity theory of behavioral contrast (Gamzu & Schwartz, 1973). The theory proposes that behavioral contrast-response rate increases in one component (S+) of the schedule resulting from a reduction in the frequency of reinforcement in another component (S-)-occurs beThis report is based on data presented by the author at the meetings of the Psychonomic Society, San Antonio, Texas, November 1978. A related procedure and similar data were reported independently by Coleman, Brown, and Hemmes, at the meetings of the American Psychological Association, Montreal, Canada, September, 1980. Reprints may be obtained from Henry Marcucella, Department of Psychology, Boston, Massachusetts 02215. 51 cause a differential stimulus-reinforcer dependency is imposed upon an already existing response-reinforcer dependency. The two sources of control are said to interact additively to generate a higher response rate than either dependency alone.Support for this view of contrast is provid...

Specification of the stimulus-reinforcer relation in multiple schedules: Delay and probability of reinforcement

“…Peck rate returned to baseline levels when the S-SR contingency was removed in Phase 3. Similar data were reported by Marcucella (1981). These results, together with the stimulus-specificity of performance changes, indicate that the S-SR contingency, rather than adventitious reinforcement of Component 1 keypecks by Component 2 reinforcers, was responsible for the behavioral effect.…”

“…The relative delay measure and a relative waiting time analysis differ in assumptions about the number of stimulus events participating in the stimulusreinforcer relation, that is, all vs. one. Data relevant to this issue come from a study by Marcucella (1981), who used a procedure similar to that in Experiment I, except that Component 1 of the negative sequence was uncued; that is, the key remained the same color, as in Component 2. Marcucella found that keypecking emerged in Component 1 of the positive sequence whether Component 1 in the negative sequence was differentially cued or not, a finding readily accommodated by a waiting time analysis, as modified for the present study, but not by the relative delay measure.…”

“…The paradigm, termed here the "temporal separation procedure," was developed independently by the present authors (Coleman,Brown,& Hemmes,Note 1) and by Marcucella (1981). Unlike autoshaping, the temporal separation procedure includes both S-SR and R-SR contingencies.…”

Perhaps More Consideration of Pavlovian-Operant Interaction May Improve the Clinical Efficacy of Behaviorally Based Drug Treatment Programs

“…Marcucella (1981) showed that Pavlovian-elicited key pecks in pigeons emerged subsequent to operant discriminative functions, and extinguished first. In that study, elicited key pecks were dissociated from operant key pecks despite comparable reinforcement magnitudes (i.e., between the CS → US and response → reinforcer) that varied only as a function of the operant response.…”

Responding of Pigeons Under Variable‐interval Schedules of Unsignaled, Briefly Signaled, and Completely Signaled Delays to Reinforcement

“…Operant and respondent functions of stimuli are often separable. Marcucella (1981), for example, showed that pigeons pecked a key when it was lit briefly with a stimulus that preceded a period of VI reinforcement more often than a different color key that preceded a period of extinction (thus reflecting the respondent relationship between the key and subsequent reinforcement), whereas operant key pecking following the two brief stimulus presentations occurred at nearly the same rate, indicating no discriminative control by the brief stimuli. It may be that further experimentation will allow us to separate the reinforcing from the discriminative and respondent functions of stimuli that signal delays to reinforcement.…”