Variable-interval punishment during variable-interval reinforcement

Variable-interval punishment was superimposed on a variable-interval food reinforcement baseline for three groups of rats. The value for the variable-interval punishment schedule was the same as that for the variable-interval food reinforcement schedule, although the two schedules were programmed independently. The three groups were Variable Intervals 0.5, 1, and 3 min. Little or no suppression occurred in the three groups at mild (0.2 and 0.4 ma) intensities of punishment, but at 0.6 ma, complete suppression occurred almost uniformly. During continued punishment, there was no consistent recovery toward the pre-punishment baseline at suppressing intensities of punishment. After punishment was discontinued, recovery from suppression was more rapid the lower the punishment intensity, and the lower the value of the variable-interval schedules of reinforcement and punishment.     

Abortive responding during punishment of bar holding

A continuous chain of homogeneous responding was established in rats by training animals to hold a lever down for 10 sec or longer before releasing it for food reinforcement. When criterion releases were subsequently punished, completed holding chains were greatly suppressed, aborted chains increased markedly, while the rate of chain initiations remained unchanged.     

Impaired cognitive control during reward pursuit and punishment avoidance

Motivation and Emotion - Two experiments were conducted to examine how cognitive control is modulated by response-contingent reward (Experiment 1) and response-contingent punishment (Experiment 2)....     

The deterrent effect of capital punishment during the 1950s

This investigation examines the deterrence hypothesis of an inverse relationship between state execution rates and homicides. Although this question has received some attention in recent studies, the findings of these investigations are mixed. Cross-sectional analyses of states have typically shown execution and homicide rates to be positively associated, while at least two national time-series studies report support for the deterrence hypothesis. To test whether these divergent findings are result of the two different methodologies employed (cross-sectional vs. time-series), a methodology that combines the strengths of each is used in the present study. For the period 1950 to 1960, we examine cross-sectionally for states the relationship between changes in execution rates and changes in murder rates. This analysis does not find support for the deterrence argument for the certainty of the death penalty when a number of models of the execution rate--murder rate relationship are considered, and when a variety of imprisonment and socio-demographic factors are considered as control variables.     

Dorsal striatum responses to reward and punishment: Effects of valence and magnitude manipulations

The goal of this research was to further our understanding of how the striatum responds to the delivery of affective feedback. Previously, we had found that the striatum showed a pattern of sustained activation after presentation of a monetary reward, in contrast to a decrease in the hemodynamic response after a punishment. In this study, we tested whether the activity of the striatum could be modulated by parametric variations in the amount of financial reward or punishment. We used an event-related fMRI design in which participants received large or small monetary rewards or punishments after performance in a gambling task. A parametric ordering of conditions was observed in the dorsal striatum according to both magnitude and valence. In addition, an early response to the presentation of feedback was observed and replicated in a second experiment with increased temporal resolution. This study further implicates the dorsal striatum as an integral component of a reward circuitry responsible for the control of motivated behavior, serving to code for such feedback properties as valence and magnitude.     

Fixed-ratio punishment

Responses were maintained by a variable-interval schedule of food reinforcement. At the same time, punishment was delivered following every nth response (fixed-ratio punishment). The introduction of fixed-ratio punishment produced an initial phase during which the emission of responses was positively accelerated between punishments. Eventually, the degree of positive acceleration was reduced and a uniform but reduced rate of responding emerged. Large changes in the over-all level of responding were produced by the intensity of punishment, the value of the punishment ratio, and the level of food deprivation. The uniformity of response rate between punishments was invariant in spite of these changes in over-all rate and contrary to some plausible a priori theoretical considerations. Fixed-ratio punishment also produced phenomena previously observed under continuous punishment: warm-up effect and a compensatory increase. This type of intermittent punishment produced less rapid and less complete suppression than did continuous punishment.     

Conditioned punishment

Responses of pigeons were maintained by a VI schedule of food reinforcement. Conditioned punishment was programmed by having these responses concurrently produce an originally neutral stimulus. The effectiveness of this response-contingent stimulus was maintained by infrequent and prearranged stimulus-shock pairings delivered independently of responses. This conditioned punishment procedure reduced the overall response rate as long as the procedure was in effect. The extent and durability of the reduction was a function of the intensity of the shock that was paired with the stimulus. Analysis of the reduction in the overall response rate revealed: (1) a reduction of responses occurring in the absence of the response-contingent stimulus, which was designated as a “punishing” effect, and (2) a reduction of responses during the response-contingent stimulus, which was designated as a “suppressive” effect.     

Fixed-interval punishment

The average rate of bar-pressing maintained by a variable-interval schedule of milk reinforcement in 33 rats was found to be a decreasing function of intensity of concurrent punishment and, over a wide range of shock intensities, was inversely related to punishment frequency. Cumulative records were, however, negatively accelerated during 30-min punishment sessions with complete suppression occurring earlier and earlier (after fewer and fewer shocks) as intensity increased. In addition, acceleration was often observed between successive fixed-interval shock presentations and, at low and moderate intensities, bursts of responding occurred after each shock. The time to recover between punishment sessions (post-punishment recovery) was an increasing monotonic function of punishment intensity.     

Overt activity during conditioned suppression: a search for punishment artifacts

Pigeons, previously trained to peck a key (using food as the reinforcer), were permitted unlimited access to food and, concurrently, key pecking was allowed to go unreinforced until all pecking ceased. A tone ending with electrical shock was then repeatedly presented in an effort to establish the tone as a potentially suppressing stimulus. When key pecking was later reestablished, tone presentation (without shock) sharply reduced the rate of pecks. At selected points throughout the experiment, special observation procedures supplemented the recordings of key pecks and provided detailed fine-grain protocols of the birds' overt movements during the periods before, during, and after tone presentations. Results indicated that neither punishment of key pecks nor punishment of other overt movements was a necessary precursor to the conditioned suppression observed in the final stage. As such, the findings support interpretations of conditioned suppression that characterize the phenomenon as reflecting a conditioned emotional reaction that either directly or indirectly inhibits overt activity.     

Children’s competitive peer aggression during reward and punishment

Behavior‐disordered children (N = 65) competed with a presumed unknown peer on consecutive administrations of an analogue aggression task of instrumental aggression (blocking the opponent’s game) and hostile aggression (sending the opponent a noise). The first administration as a reward‐only, nonpunishment condition. The second administration contained both reward and punishment conditions. Results indicated clear differences on aggressive responding during conditions of reward and punishment. Significant correlations were found between instrumental aggression during reward across the two administrations, whereas correlations between aggression during reward and aggression during punishment were nonsignificant. Teacher ratings of Covert‐Proactive Aggression correlated with analogue task instrumental aggression but not with hostile aggression on both administrations. Aggression during punishment was significantly correlated with Continuous Performance Test inattention and impulsivity scores, suggesting that impulsivity and inattention may play an important role in children’s ability to inhibit aggression during cues for punishment. These data indicate the utility of a laboratory analogue procedure to assess conditions associated with childhood aggression and to further our understanding of childhood aggression subtypes. Aggr. Behav. 27:1–13, 2001. © 2001 Wiley‐Liss, Inc.