Response-outcome contingency: Behavioral and judgmental effects of appetitive and aversive outcomes with college students

In two experiments, positive, negative, and zero response-outcome contingencies were responded to and rated by college students under a free-operant procedure. In Experiment 1, outcomes were either neutral or were associated with point gain. In Experiment 2, subjects were administered different outcome treatments: neutral outcomes, outcomes associated with money gain, or outcomes associated with money loss. In both experiments, subjects' judgments of response-outcome contingency and their operant responses were each strong linear functions of ΔP, the difference between the probability of an outcome given a response and the probability of an outcome given no response. Appetitive and aversive outcomes produced opposite and symmetrical response patterns. In Experiment 1, no differences in ratings occurred with neutral or appetitive outcomes; however, in Experiment 2, more potent appetitve outcomes led to somewhat more extreme ratings than either neutral or aversive outcomes. Increasing outcome probability produced only a slight bias in ratings of noncontingent problems in Experiment 1 and no bias in Experiment 2. Contrary to predictions derived from an analysis of superstitious behavior, increasing outcome probability in noncontingent problems decreased operant responding when outcomes were appetitive and increased operant responding when outcomes were aversive. Trend analyses revealed that Δ P was superior to several other metrics in predicting subjects' estimates of contingency and the behavioral effects of contingency. Operant responding was in closer accord with matching predictions than with maximizing predictions.     

Conformity of two sociometric relations

The problem of comparing two sociometric relations or measurements (A andB) recorded in distinct sociomatrices was originally discussed by Katz and Powell in the early 1950's and Hubert and Baker in the late 1970's. The problem is considered again using a probabilistic model designed specifically for discrete-valued network measurements. The model allows for the presence of various structural tendencies, such as reciprocity and differential popularity. A parameter that isolates the tendency for actors to choose other actors on both relations simultaneously is introduced, and estimated conditional on the presence of other parameters that reflect additional important network properties. The parameter is presented as a symmetric index but is also generalized to the predictive (A onB orB onA) situation. This approach to the problem is illustrated with the same data used by the earlier solutions, and the unique nature of the two relations in the data set (A = received choices,B = perceived choices), as it affects the modeling, is discussed. Significance tests for the parameter and related parameters are described, as well as an extension to more than two relations.Research support provided by National Science Grant #SES84-08626 to the University of Illinois at Urbana-Champaign. I am grateful to Dawn Iacobucci and Sheila Weaver for assistance with the research reported here, and to Carolyn Anderson, James Green, David Holtgrave, and four anonymous referees for comments on the paper.     

The role of the magazine-response contingency on signal-directed responding in pigeons

Three experiments used a procedure for directly delivering water into the thirsty pigeon's mouth to explore the role that the instrumental magazine contingency plays in autoshaped responding. Magazine training was accomplished by requiring birds to contact a “magazine” key when it was illuminated, in order to obtain intraoral injections of water. Other subjects received water injections independent of a magazine-response contingency. Subsequently, magazine-trained subjects showed a transient enhancement in responding to the illumination of another “signal” key, whether that stimulus was presented alone or paired with water delivery. The overall level of maintained autoshaped responding was little influenced by the instrumental magazine contingency, although the within-trial time course of signal-directed responding was affected. When illumination of the signal key preceded access to water only when the signal was not contacted, pigeons directed many responses toward the signal key. However, there was no evidence that the instrumental magazine contingency enhanced responding on this omission schedule of reinforcement. These results thus confirm a small, but measurable contribution of the magazine-response contingency to signal-directed responding; they fail to support the conclusion that the instrumental magazine contingency greatly affects the outcomes of autoshaping studies.     

Conditioning of within-trial patterns of key pecking in pigeons

The possibility of conditioning systematic patterns of responding during brief discrete trials was studied by requiring hungry pigeons to key peck and then pause or to pause and then key peck in order to gain access to food. These schedules were highly effective in promoting decelerated and accelerated rates of responding, respectively, within individual trials; indeed, performance was quite similar to that observed when explicit external stimuli were correlated with “peck” and “pause” portions of the daily trials. Finally, schedules of reinforcement that did not selectively reinforce peck-pause or pause-peck patterns neither generated these patterns nor maintained them at the previous high levels. The results, therefore, confirm Shimp's (1976) proposal that organized groupings of discrete responses may function as operants—even in the absence of strict response-reinforcer contiguity.     

Trace autoshaping: Acquisition, maintenance, and path dependence at long trace intervals

The pigeon's tendency to acquire and maintain signal-directed key pecking under a trace conditioning procedure was parametrically examined. In Experiment 1, the percentage of CS trials with a key peck response was a decreasing function of the trace interval for separate groups of pigeons. The majority of subjects acquired signal-directed key pecking with trace intervals as long as 36 sec. In Experiment 2, differential maintenance of key pecking occurred across trace intervals in a within-subject procedure. Maintenance of key pecking at 36- and 60-sec trace intervals was path dependent in that responding depended on the subject's performance under the preceding trace interval.     

Limulus psychophysics: Increment threshold

Prior temporal summation work had indicated that the sensory code for certain behaviors (in bothLimulus and humans) can be understood if one suggests that the central nervous system analyzes the integral of the photoreceptor potential. An independent test of this suggestion is available because (inLimulus) the physiological increment threshold function obtained from the receptor potential integral is inflected, whereas that obtained from the initial transient peak of the receptor potential is not. The behavioral increment threshold function was measured inLimulus and found to be inflected. Fechner’s scaling assumption (that equally detectable stimulus increments are mediated by sensory signals of equal size) was supported by the fact that a theoretical function, which was calculated from the receptor integral intensity-response function by using Fechner’s scaling assumption, was able to fit the behavioral increment threshold function quite well. Furthermore, the variability of the behavioral data was proportional to the receptor integral variability. A seasonal effect was observed: Fall animals were more sensitive and had a higher criterion than winter animals. These findings permit the specification of the rerceptor potential that mediates this particular behavior at threshold: It has a steady-state amplitude of 7 mV in winter and 16 mV in fall. Taken in conjunction with the results of earlier temporal summation work indicating that the threshold receptor potential is 4.5 sec long, this specification implies that at least some behaviors are mediated by large, long sensory signals, which have properties very different from those of small, short signals, particularly with regard to both linearity and their relative dependence on time vs. energy.     

Distinguishing between stochastic models of heterogeneity and contagion

Historically, the Poisson process has been the “benchmark” model for many stochastic processes. When event counts from a particular process fail to be described adequately by a Poisson distribution, a researcher may turn to generalized Poisson processes to model the empirical data more accurately. Two common generalizations are the (1) heterogeneous Poisson process, in which the process rate is a Gamma random variable, and (2) contagious Poisson process, in which the process rate depends linearly on the current state of the process. Paradoxically, both the heterogeneous and contagious processes yield the same theoretical distribution for the number of events that occur in a single interval of time. Consequently, distinguishing between these two using event counts can be difficult. This situation is discussed, first reviewing the models and distribution, then giving strategies for choosing between them using event count data, and demonstrating these techniques on episodes of hospitalization for schizophrenia.     

Predicting counterproductivity among drug store applicants

The ability of a preemployment integrity test to predict future admissions of counterproductive behavior by employees was investigated. Job applicants completed the London House Personnel Selection Inventory (PSI) as part of an overall selection process. Approximately one year later, a survey was sent to applicants at their home addresses. The survey asked for the frequency with which these applicants engaged in a variety of counterproductive behaviors at work. The PSI accurately predicted admissions of cash and merchandise theft, theft of time, behaviors associated with poor job performance, and the frequency with which the theft of other employees was observed.     

Application of an Integrated Behavioral Model to Predict Condom Use: A Prospective Study Among High HIV Risk Groups1

An integrated theoretical model using constructs from multiple behavioral models was applied to understand and predict condom use among a sample of injecting drug users, commercial sex workers, men who have sex with men, and multipartnered heterosexuals. Elicitation interviews were conducted to develop a questionnaire to measure model constructs that may be predictive of condom use for sex with vaginal, anal, and oral regular and casual partners. A prospective survey design was used, with 993 participants interviewed at Time 1, and 686 returning for Time 2 interviews 3 months later. Regression analyses were conducted using Time 1 measures to predict intention and Time 2 behavior. Strong support was found for a model that includes attitude, social norm, and facilitators/constraints as predictors of behavior, with multiple correlations in the 0.20 to 0.40 range. Findings also indicate perceived control and facilitators/constraints are distinct constructs and both, along with attitude and social norm, contribute to explaining behavioral intention. Implications for intervention development are discussed.     

COMPARATIVE COGNITION:

Abstract— Human and nonhuman animals alike must adjust to complex and ever-changing circumstances if they are to survive and reproduce. Advanced neural mechanisms enable animals to remember the past, to act in the present, and to plan for the future. Exploring the species generality of cognitive processes in behavior is central to the field of comparative cognition. A comparative perspective may not only broaden but also deepen our understanding of cognition—both in human and in nonhuman animals.