Judging response-outcome relations: The role of response-outcome contingency,outcome probability,and method of information presentation

A series of four experiments investigated college students’ judgments of interevent contingency. Subjects were asked to judge the effect of a discrete response Itapping a wire) on the occurrence of a brief outcome (a radio’s buzzing). Pairings of the possible event-state combinations (response-outcome, response-no outcome, no response-outcome, no response-no outcome) were presented in a summary-table (Experiments 2 and 4), in an unbroken-time-line (Experimente 1, 2, and 4), or in a broken-time-line format (Experiment 3). Subjects judged the extent to which the response caused the outcome or prevented it from occurring. Across all methods of information presentation, judgments were a positive function of response-outcome contingency and outcome probability. In the unbroken-time-line condition, judgments of negative response-outcome contingencies were less extreme than judgments of equivalent positive contingencies. This asymmetry was smaller in the broken-time-line condition and in those conditions in which subjects were encouraged to segment an unbroken time line into discrete response outcome units. Finally, judgments of positive and negative relationships were generally symmetrical in the summary-table condition. Relative to the two time-line portrayals, summary table judgments were also less influenced by the overall probability of outcome occurrence. These judgment differences among format conditions suggest that, depending on the method of information presentation, subjects differently partition event sequences into discrete event pairings.     

Performance of pigeons on delayed simple and conditional discriminations under equivalent training procedures

A pair of experiments investigated the short-term memory of pigeons under delayed simple and conditional discriminations. Trial sequences in both discriminations consisted of a color as the sample stimulus, a memory interval, a line orientation as the test stimulus, and a trial outcome, which was either food reinforcement or blackout. Pecking rates during the test stimulus defined discrimination performance. In the simple discrimination, the sample provided the necessary information regarding the subsequent trial outcome. In the conditional discrimination, the sample and test stimuli conjointly provided this information. In Experiment 1, the two procedures were compared with independent groups of pigeons. In Experiment 2, the comparison was made within subjects. The simple discrimination was acquired more quickly and was performed better with a memory requirement. Introduction of long delays disrupted performance even at shorter delays in both discriminations. Postulation of prospective as well as retrospective mediating processes facilitates the interpretation of these results.     

The pigeon's variability discrimination with lists of successively presented visual stimuli.

Pigeons previously trained to peck 1 button (same) after the successive presentation of 16 identical pictures and to peck a 2nd button (different) after the successive presentation of 16 nonidentical pictures were tested on lists involving different degrees of variability, different list lengths, and different temporal organizations of list items. The pigeons' performances on this successive same-different task revealed a strong sensitivity to list entropy; but, their discrimination was also affected by their memory for list items and by the accumulated evidence for a same versus a different response. Statistical models confirmed and quantified the importance of these additional factors.     

Time and duration: A persistent illusion

Attention is drawn to a persistent illusory correlation between the words time and duration. This illusory correlation led Ward (1991) to conclude that neural adaptation and informational adaptation are asynchronous. But when the illusion is dispelled so that like is compared to like, it then appears possible that informational adaptation and neural adaptation may be closely linked.     

Analyzing the random control procedure: Effects of paired and unpaired CSs and USs on autoshaping the chick's key peck with heat reinforcement

A series of five experiments using a total of 264 subjects investigated the effects of paired and unpaired key light (CS) and heat (US) stimuli on autoshaping the chick's key peck. Experiment 1 established that paired presentations of CS and US promoted a more rapid rise in key pecking than did randomly presented CSs and USs and that the specific sequence of stimuli under the random control procedure affected key pecking performance. Experiment 2 used a trace conditioning procedure to determine the role of the CS-US interval on autoshaping and to define empirically unpaired CSs and USs. Key pecking declined as the trace delay interval was increased from 0 to 25 sec; at 25 sec, no conditioning of key pecking occurred. Experiments 3–5 assessed the effects on autoshaped key pecking of (a) number of daily CS-US pairings, (b) added unpaired CS presentations, and (c) added unpaired US presentations, since paired and random control schedules differed in all of these respects. Reduction in the number of CS-US pairings slowed the acquisition of key pecking as did the concurrent addition of nonreinforced CSs and unsignaled USs. These results support theories of association formation that stress the effects of both paired and unpaired CSs and USs.     

Sequential social network data

A new method is proposed for the statistical analysis of dyadic social interaction data measured over time. The data to be studied are assumed to be realizations of a social network of a fixed set of actors interacting on a single relation. The method is based on loglinear models for the probabilities for various dyad (or actor pair) states and generalizes the statistical methods proposed by Holland and Leinhardt (1981), Fienberg, Meyer, & Wasserman (1985), and Wasserman (1987) for social network data. Two statistical models are described: the first is an associative approach that allows for the study of how the network has changed over time; the second is a predictive approach that permits the researcher to model one time point as a function of previous time points. These approaches are briefly contrasted with earlier methods for the sequential analysis of social networks and are illustrated with an example of longitudinal sociometric data.Research support provided by National Science Foundation Grant #SES84-08626 to the University of Illinois at Urbana-Champaign and by a predoctoral traineeship awarded to the second author by the Quantitative Methods Program of the Department of Psychology, University of Illinois at Urbana-Champaign, funded by ADAHMA, National Research Service Award #MH14257. We thank the editor and three anonymous referees for helpful comments.This paper is based on research presented at the 1986 Annual Meeting of the Psychometric Society, Toronto, Ontario, June, 1986.     

College students' responding to and rating of contingency relations: The role of temporal contiguity

Two experiments investigated the role of temporal contiguity in college students' responding to and rating of contingency relations during operant conditioning. Schedules were devised that determined when but not whether appetitive or aversive events would occur. Subjects' reports concerning the schedules were obtained by means of a 200-point rating scale, anchored by the phrases “prevents the light from occurring” (−100) and “causes the light to occur” (+100). When tapping a telegraph key advanced the time of point gain, responding was maintained or increased and subjects gave positive ratings. When tapping a telegraph key advanced the time of point loss, subjects also gave positive ratings, but responding now decreased. When key tapping delayed the time of point gain, responding decreased and subjects gave negative ratings. When key tapping delayed the time of point loss, subjects also gave negative ratings, but responding now increased. These findings implicate response-outcome contiguity as an important contributor to causal perception and to reinforcement and punishment effects. Other accounts—such as those stressing the local probabilistic relation between response and outcome or the molar correlation between response rate and outcome rate—were seen to be less preferred interpretations of these and other results.     

Memory for sequences of stimuli and responses

Two experiments sought to determine if pigeons could discriminate and remember recent sequences of stimuli and responses. A variant of Konorski's short-term memory procedure involving successive presentation of sample and test stimuli was used. The samples were stimulus-response pairs of the form, (S-R)₁–(S-R)₂. Differential test responding disclosed memory of the two-item samples, with birds showing earlier and greater control by the second item than the first (Experiment 1). When the retention interval separating the second item of the sample sequence from the test stimulus was lenghtened from .5 to 2.0 or 4.0 sec, a systematic loss of stimulus control resulted; however, when varied over the same temporal range, the interval between the two items of the sample sequence had a much smaller effect, or none at all (Experiment 2). These results support an account of response-sequence differentiation that stresses short-term memory of organized behavior patterns.     

Suicide risk at juvenile justice intake

Many risks for suicidal behavior, identified in population samples, are elevated in justice youth. We examined whether risks operate similarly in a justice sample. We measured suicidal behavior and disorder on the Diagnostic Interview Schedule for Children in 991 randomly selected youths, and examined associations between demographic, offense, and disorder characteristics and past attempts. Recent attempts were more common in girls, in those with depression or substance disorder, and in violent offenders. While more girls reported recent attempts regardless of depression, depressed boys' attempt risk was as high as girls'. Depression contributed more to attempt history than did substance disorder.     

Figure-ground assignment in pigeons: evidence for a figural benefit

Four pigeons discriminated whether a target spot appeared on a colored figural shape or on a differently colored background by first pecking the target and then reporting its location: on the figure or the background. We recorded three dependent variables: target detection time, choice response time, and choice accuracy. The birds were faster to detect the target, to report its location, and to learn the correct response on figure trials than on background trials. Later tests suggested that the pigeons might have attended to the figural region as a whole rather than using local properties in performing the figure-background discrimination. The location of the figural region did not affect figure-ground assignment. Finally, when 4 other pigeons had to detect and peck the target without making a choice report, no figural advantage emerged in target detection time, suggesting that the birds' attention may not have been automatically summoned to the figural region.