Duration-reduction of avoidance sessions as negative reinforcement

Five rats were exposed to a shock-postponement procedure in which responses on each of two levers initially had equivalent effects. After an initial training sequence that ensured at least some responding on each lever, an additional consequence was made conjointly operative on the previously less-preferred lever for each animal. Each response on this lever continued to postpone shock, but also reduced the session duration by one minute. The conjoint contingencies were operative until, through session-shortening responses and the passage of time, the session was scheduled to end in two minutes; during the final two minutes the session-shortening contingency was disabled while the shock-postponement contingency continued to be operative on both levers. When responding shifted to a predominance on the session-shortening lever, the conjoint contingency was shifted to the other lever; for four of the five rats this reversal was followed by two additional reversals. Two of the rats' responding showed clear, strong, and unambiguous sensitivity to the session-shortening contingency. The responding of two others was also systematically controlled by that contingency, but the effects were less clearcut. The fifth animal showed an initial shift when session-shortening was introduced, but its subsequent behavior proved insensitive to reversals of procedure. The results clearly indicate a sensitivity of behavior to events on a time scale quite distinct from that of immediate consequences. They also support an interpretation of avoidance sessions, considered in their entirety, as events whose contingent relationship to behavior can affect that behavior—even in the absence of stimuli that delineate those relationships. Finally, these results support an interpretation of aversively based conditioning within a broader context, analogous to the “open versus closed economy” interpretation of appetitively controlled behavior.     

Performance of humans in concurrent avoidance/positive-reinforcement schedules

Performance maintained under concurrent schedules consisting of a variable-interval avoidance component and a variable-interval positive-reinforcement component was studied in three human subjects using points exchangeable for money as the reinforcer. The rate of responding in the avoidance component increased, and the rate of responding in the positive-reinforcement component declined, as a function of the frequency of point-losses avoided in the avoidance component. The performance of all three subjects conformed to equations proposed by Herrnstein to describe behavior in concurrent schedules. The logarithms of the ratios of the response rates in the two components, and the logarithms of the ratios of the times spent in the two components, were linearly related to the logarithms of the ratios of the frequency of loss avoidance in the avoidance component to the frequency of reinforcement in the positive-reinforcement component. When a changeover delay of 5.0 sec was imposed, the slopes of the linear functions were close to 1.0 in the case of two subjects, whereas the third subject exhibited significant undermatching. For two subjects the changeover delay was then reduced to 2.0 sec; in both cases the slopes of the linear functions were lower than under the 5.0-sec condition. One subject participated in a third phase, in which no changeover delay was imposed; there was a further reduction in the slopes of the linear functions.     

Signalled free-operant avoidance of shock by pigeons pecking a key

Two pigeons were trained to peck a key under a free-operant avoidance schedule. Then, changes in key color signalled the beginning (safe period) and the end (warning period) of the response-shock interval, with a response required to change the key color. Finally, a change in key color signalled the warning period and either a response or a shock reinstated the safe stimulus. During signalled avoidance, response rate was higher during the warning stimulus than during the safe stimulus. More responding tended to occur in the warning stimulus when it was terminated by either a response or a shock than by only a response. In either procedure, response latency during the warning stimulus was a function of the duration of the warning stimulus. In general, response and shock rate were higher during unsignalled than during signalled avoidance. When the warning stimulus was brief, the results were similar to those of unsignalled avoidance. These results confirm previous findings with pigeons, are in general agreement with data provided by other species in studies of signalled avoidance, and thereby indicate the transituationality of the key-pecking operant.     

Clock control of human performance on avoidance and fixed-interval schedules

The avoidance and fixed-interval performances of human subjects were studied in two experiments. Addition of time-correlated stimuli (added clock) improved behavioral efficiency, since response rates decreased without decreases in reinforcement rates. Response-dependent display of the clock maintained a second, observing response and reductions in clock duration weakened such observing behavior. Generally, the reinforcing properties of the clock were more apparent with the avoidance than with the fixed-interval schedule, a finding attributed to temporal cues already provided by delivery of the fixed-interval reinforcers. Reduced rates of the main response when the clock was dependent on an observing response were more than offset by rates of the observing response in the majority of subjects. Thus, the results do not support an interpretation of the reinforcing properties of added clocks simply in terms of work reduction.     

Human social defeat and approach–avoidance: Escalating social-evaluative threat and threat of aggression increases social avoidance

Basic research on avoidance by Murray Sidman laid the foundation for advances in the classification, conceptualization and treatment of avoidance in psychological disorders. Contemporary avoidance research is explicitly translational and increasingly focused on how competing appetitive and aversive contingencies influence avoidance. In this laboratory investigation, we examined the effects of escalating social-evaluative threat and threat of social aggression on avoidance of social interactions. During social-defeat learning, 38 adults learned to associate 9 virtual peers with an increasing probability of receiving negative evaluations. Additionally, 1 virtual peer was associated with positive evaluations. Next, in an approach–avoidance task with social-evaluative threat, 1 peer associated with negative evaluations was presented alongside the peer associated with positive evaluations. Approaching peers produced a positive or a probabilistic negative evaluation, while avoiding peers prevented a negative evaluation (and forfeited a positive evaluation). In an approach–avoidance task with social aggression, virtual peers gave and took money away from participants. Escalating social-evaluative threat and aggression increased avoidance, ratings of feeling threatened and threat expectancy and decreased ratings of peer favorableness. These findings underscore the potential of coupling social defeat and approach–avoidance paradigms for translational research on the neurobehavioral mechanisms of social approach–avoidance decision-making and anxiety.     

Horizontal eye movements foster approach to negative pictures but do not change emotional valence: A dopaminergic regulation hypothesis

A new dopaminergic regulation hypothesis is proposed based on two experiments exploring eye-movement effects. In the Eye Movement Desensitization and Reprocessing (EMDR) and Saccade-Induced Retrieval Enhancement (SIRE) domains, eye-movement mechanisms are mainly studied with explicit measures. Here implicit and explicit measures of emotion and memory for positive and negative pictures were investigated after eye movements or fixation in extreme right-handers. Eye movements enhanced explicit recognition predominantly for negative pictures. The absence of implicit repetition priming in both experiments supported a dissociation between implicit and explicit memory. Motivational eye-movement effects emerged but implicit and explicit affect remained unchanged. Experiment 2 revealed, after initial freezing to negative pictures, an acceleration, particularly of approach responses. Eye movements are postulated to foster approach towards negative memories, and promote, though dopaminergic pathways from the Superior Colliculus, enhanced explicit memory and active emotion regulation, primarily in persons with a collateralization of eye and dopamine dominance.     

Sitting with it: An investigation of the relationship between trait mindfulness and sustained attention

BackgroundSustaining attention for extended periods of time is associated with negative affect and this increase in negative affect is related to poorer task performance. Trait mindfulness has been shown to be associated with better sustained attention performance. This may be because trait mindfulness is associated with better attention ability or better emotion regulation ability.AimsThe present research aims to replicate previous findings and better understand why trait mindfulness is associated with better sustained attention performance.MethodParticipants responded to self-report questionnaires assessing their trait mindfulness, attentional control, and experiential avoidance. Next, participants performed a sustained attention task, during which they also reported their subjective feelings of discomfort and boredom. Finally, participants reported their retrospective discomfort and boredom after the task.ResultsWe replicated and extended previous findings by showing that the relationship between trait mindfulness and sustained attention performance was mediated by negative affect experienced during the task. Moreover, the correlation between trait mindfulness and sustained attention disappeared when controlling for experiential avoidance, but remined when controlling for attention control.ConclusionOur results suggest that trait mindfulness is associated with sustained attention because of enhanced emotion regulation and that enhancing affective regulation would be an effective strategy for improving sustained attention performance.     

社交焦虑大学生情绪调节灵活性：情绪内容对策略选择和使用的影响

尽管社交焦虑个体被认为存在情绪调节灵活性的不足,但至今尚不清楚这种不足究竟在于难以灵活选择策略,还是难以灵活使用策略,抑或二者兼有？对此,本研究采用情绪调节策略选择任务考察了37名高社交焦虑大学生和29名低社交焦虑大学生在面对社交-非社交情绪图片时对认知重评-回避策略的选择模式和使用效果。结果发现：在面对社交情绪图片时,高社交焦虑被试比低社交焦虑被试更少选择认知重评,而更多选择回避;在面对非社交情绪图片时,两组被试对两种策略的选择模式无显著差异。同时,无论面对社交还是非社交情绪图片,两组被试对两种策略的使用效果也无显著差异。以上结果表明,相比低社交焦虑个体,高社交焦虑个体只有在面对社交情绪刺激时才存在情绪调节灵活性的不足,且这种不足主要在于难以灵活选择策略,而非难以灵活使用策略。     

Murray Sidman: A life of giving

Murray Sidman's contributions to the science of behavior span many areas including avoidance behavior, coercion and its effects, stimulus control, errorless learning, programmed learning, stimulus equivalence, and single-subject methodology. He was also a great mentor to many and helped shape the discipline we now call behavior analysis. In this memoriam, we briefly highlight his scholarly legacy and share some personal anecdotes.