Frustration odor of rats receiving small numbers of prior rewarded running trials

Three related experiments were performed to examine trial-to-trial differences in production of frustration odor during runway extinction by rats that had received 0, 2, 4, or 6 prior rewards. Differences in odor production were indexed by the subsequent speed of escape from the runway goal box by conspecifics. The results indicated that (a) subjects will perform a hurdle-jump response to escape from frustration odor; (b) escape performance even after several prior escape trials accurately reflects trial-to-trial changes in production of frustration odor; and (c) production of frustration odor requires only 4 prior rewards. Implications of the present data for frustration analyses of the limited-trial partial reinforcement effect and future investigations of frustration odor are discussed.     

Factors affecting the measurement of classically conditioned fear in rats following exposure to escapable versus inescapable signaled shock.

Three experiments are reported in which rats first received 50 escapable or inescapable signaled-shock trials. Experiment 1 (n = 22) employed an acquired-drive paradigm and found inescapable shock subjects learned a hurdle-jump response to escape the signal less rapidly than did escapable-shock subjects. Experiment 2 (n = 24) employed a conditioned emotional response paradigm and found inescapable-shock subjects suppressed more when the signal was introduced in the appetitive bar-pressing task. Both experiments measured spontaneous activity immediately following conditioning and found no group differences. Experiment 3 (n = 39) employed the same activity task and found no difference between escapable- and inescapable-shock groups when the signal was introduced into the activity task. Both groups displayed less activity than a nonshock control group during the signal. The results suggest that lack of control over the shock in the conditioning phase did not result in an increase of conditioned fear. The results are discussed in terms of a learned active-inactive predisposition to respond.     

Learned helplessness and immunization: sensitivity to response-reinforcer independence in immunized rats

In experiments 1 and 2, we examined the learned helplessness and immunization effects using a test in which appetitive responding was extinguished by delivering noncontingent reinforcers. Contrary to learned helplessness theory, "immunized" animals showed performance virtually identical to that of animals exposed only to inescapable shock, and different from nonshocked controls. Experiment 2 suggests that the helplessness effect and the lack of immunization are not due to direct response suppression resulting from shock. In Experiment 3, where the immunization effect was assessed by measuring the acquisition of a response to obtain food when there was a positive response-reinforcer contingency, immunization was observed. These results cannot be explained on the basis of proactive interference, but suggest that animals exposed to the immunization procedure acquire an expectancy of response-reinforcer independence during inescapable shock. Thus, immunization effects may reflect the differential expression of expectancies, rather than their differential acquisition as learned helplessness theory postulates.     

Learned helplessness in the rat.

Four experiments attempted to produce behavior in the rat parallel to the behavior characteristic of learned helplessness in the dog. When rats received escapable, inescapable, or no shock and were later tested in jump-up escape, both inescapable and no-shock controls failed to escape. When bar pressing, rather than jumping up, was used as the tested escape response, fixed ratio (FR) 3 was interfered with by inescapable shock, but not lesser ratios. With FR-3, the no-shock control escaped well. Interference with escape was shown to be a function of the inescapability of shock and not shock per se: Rats that were "put through" and learned a prior jump-up escape did not become passive, but their yoked, inescapable partners did. Rats, as well as dogs, fail to escape shock as a function of prior inescapability, exhibiting learned helplessness.     

Therapy and immunization of long-term analgesia in rats

Three experiments are reported which examine the effects of experience with escapable shock either subsequent to (Experiment 1) or prior to (Experiments 2 and 3) a session of inescapable shock on the subsequently produced long-term analgesic reaction in rats. Experment 1 demonstrated that experience with escapable shock 4 hr after a session of inescapable tail shock completely reverses the analgesic response that is normally observed 24 hr later upon reexposure to shock. The escapability of the shock was shown to be the important factor in reversing the analgesic reaction, since subjects given inescapable shock in amounts equivalent to escape subjects exhibited no reduction in analgesia. Experiment 2 showed that experience with escapable shock 4 hr prior to a session of inescapable tail shock could also completely eliminate the long-term analgesic reaction. Experiment 3 replicated the results of Experiment 2, but employed a different escape task and temporal parameters in order to extend the generality of the findings, and to more closely match the procedures employed in behavioral experiments reported by J. L. Williams and S. F. Maier (Journal of Experimental Psychology: Animal Behavior Processes, 1977, 3, 240–253). The implications of these results for the areas of pain control and learned helplessness were discussed.     

Pavlovian processes and response competition as determinants of avoidance response-prevention effects

Two experiments investigated the facilitation of avoidance extinction by exposure to lengthy (5-sec) shock during avoidance response prevention. In Experiment 1, animals exposed to light only or to light-shock pairings during response prevention showed equal facilitation of extinction relative to shock-only animals or to animals receiving no response prevention. Preshock rearing, directly antagonistic to the avoidance response, developed for shocked animals during response prevention and persisted during extinction for light-shock animals. Immediately before extinction, half of each group was permitted a single escape from a light-shock compound by means of the response previously required for avoidance. The only effect was upon the extinction performance of light-shock animals. Rearing was eliminated and extinction responding increased to a level far above that for any of the other animals. Experiment 2 demonstrated that the shock-only treatment affected the extinction performance and rearing of nonescape and escape animals in a manner entirely equivalent to the effects of the light-shock treatment of Experiment 1, provided stimulus conditions (light absent) were the same for all experimental phases. Thus, lengthy shock during avoidance response prevention simultaneously leads to the acquisition of competing behavior and enhances control by a warning signal or contextual stimuli over the avoidance response. Implications for the CS-only response-prevention treatment and the transfer of aversive control are discussed.     

习得性无助是习得的吗？——对习得性无助理论及其反思的评述

Seligman和Maier（1967）在动物实验的基础上提出了著名的习得性无助理论,但在2016年,Maier和Seligman二人却联合发文对该理论进行了反思：从最新的神经生物学证据来看,习得性无助的经典理论概括存在基本错误,习得性无助并非习得而来！所谓“习得性”无助,实质上是动物对厌恶刺激长期作用的先天适应性反应,而非认知学习的结果。本文简要梳理习得性无助理论的起源与发展,深入分析这一反思的核心内容、依据及意义,对其中否定习得性无助理论概括的观点,从证据的充分性、研究范式的效度、规范概念等角度作了进行进一步的探讨,并结合新的实验范式对未来研究提出建议。     

Learned helplessness in groups

Group learned helplessness is demonstrated in Experiment I. Groups of 2 tried to turn off noise by their joint action. In the solvable group (S), noise offset was contingent on their sequence of button pushing. In the yoked, unsolvable group (U), noise offset was independent of all sequences of button pushes they produced. In a practice group (O). subjects practiced coordinated sequences of button pushes with their partners, but heard no noise. Later, all 3 groups were tested in pairs in a shuttlebox which required coordinated joint responding to turn off noise. The unsolvable group escaped more poorly than the other 2 groups, paralleling helplessness effects with individuals. Experiment 2 and 3 found no transfer from individual helplessness training to group testing and no transfer from group helplessness training to individual testing. We suggest that the same mechanism, the expectation of response ineffectiveness, may mediate both individual and group learned helplessness.     

Instrumental to Pavlovian transfer: Learning about response-reinforcer contingencies affects subsequent learning about stimulus-reinforcer contingencies

Two experiments examined the interaction between response-reinforcer (R-S) and stimulus-reinforcer (S-S) learning. In both experiments, three groups of rats were exposed to escapable, yoked inescapable, or no shocks. All groups were then exposed to either two or four sessions of truly random control (TRC) conditioning (Experiment 1) or to an excitatory conditioning procedure (Experiment 2) in which the shock US occurred with either moderate or low probability. Excitatory strength of the CS was assessed during extinction by a conditioned emotional response (CER) test. Inescapably shocked rats conditioned less than did their escapably shocked and nonshocked partners under all TRC conditions of Experiment 1, but only conditioned less than their partners in Experiment 2 when exposed to the moderate CS-US contingency for four sessions. These results provide a clear demonstration of transfer between instrumental training and Pavlovian excitatory conditioning and thus, support the influence of learning about R-S contingencies upon subsequent learning about S-S contingencies. Both a contextual blocking interpretation and an expansion of the learned helplessness theory were discussed as possible explanations of this transfer.     

Learned helplessness in the rat: time course, immunization, and reversibility.

Rats, like dogs, fail to escape following exposure to inescapable shock. This failure to escape does not dissipate in time; rats fail to escape 5 min, 1 hr., 4 hr., 24 hr., and 1 wk. after receiving inescapable shock. Rats that first learned to jump up to escape were not retarded later at bar pressing to escape following inescapable shock. Failure to escape can be broken up by forcibly exposing the rat to an escape contingency. Therefore, the effects of inescapable shock in the rat parallel learned helplessness effects in the dog.     

Incentive shift in the rat following training to resist punishment

An incentive shift paradigm was used to test for the similarity of fear and frustration. In Experiment 1, rats trained to resist electric shock punishment showed neither a negative contrast effect nor any performance decrement when reward was shifted from 10 to one pellet. Experiment 2 replicated the basic findings of Experiment 1, but also showed that punishment training did not influence the magnitude of performance shift for animals receiving increases in reward magnitude. Finally, Experiment 3 additionally found that rats sensitized to punishment showed an increase in negative contrast effect. These results support the hypothesized functional similarity between conditioned fear and conditioned frustration with learned persistence or sensitivity to one generalizing to the other as suggested by Amsel's (1972) theory of persistence.     

The debilitating effect of exposure to noncontingent escape: A test of the learned helplessness model

Two studies were conducted to test the hypothesis that exposure to non-contingent escape leads to performance deficits similar to those observed when subjects are exposed to noncontingent aversive outcomes from which there is no escape, and that causal attributions mediate these deficits. Previous attempts to produce “appetitive helplessness” (deficits resulting from exposure to noncontingent positive events) have been plagued by subjects' tendency to believe that they are responsible for positive events. In Experiment 1, 40 subjects were exposed to contingent or noncontingent noise escape trials. As predicted by the learned helplessness model, subjects who received inescapable noise performed less well on a subsequent anagram task than subjects exposed to escapable noise. Similarly, subjects who escaped from the noise owing to the benevolence of a powerful other rather than because of their own efforts, showed performance deficits paralleling those of the inescapable noise subjects. In Experiment 2, subjects who escaped an aversive tone through no effort of their own showed subsequent performance deficits, but globality of their self-reported attributions did not predict subsequent anagram performance. The results of these studies provide support for the hypothesis that uncontrollability, independent of the valence of a particular outcome, is responsible for helplessness deficits, but do not support the mediational role of attributions, at least in the laboratory.     

Acquisition of a free-operant-appetitive response in pigeons as a function of prior experience with response-independent food

Deficits in learning to escape from electric shock following exposure to response-independent preshocks have frequently been reported and have been referred to as learned helplessness. Experiments were conducted in order to determine whether a phenomenon similar to learned helplessness could be induced in appetitive free-operant procedures with pigeons. Subjects received preliminary training under one of the following conditions; protracted exposure to response-dependent grain presentations (key pecking), protracted exposure to response-independent grain deliveries, or short-term hopper training. Subjects were then tested for acquisition of a treadle-pressing response which was the only means of access to grain in the experimental chamber. The acquisition of the treadle-pressing response was retarded following protracted exposure to response-independent grain deliveries and the degree of this retardation was related to the complexity of the response-reinforcer contingency.     

Helplessness,stress level,and the coronary-prone behavior pattern

Two experiments were conducted to examine the relationship between stress level and learned helplessness in human subjects. Experiment I subjected subjects to loud or moderate noise in order to induce differential stress. Half of the subjects within each stress group were unable to escape from a series of noise bursts, whereas the other half could terminate each burst by manipulating appropriate switches. After the pretreatment series, the same noise was again delivered to subjects, all of whom could now escape or avoid noise by making an appropriate response on a shuttle box. Inescapable (helplessness) pretreatment interfered with escape learning in the second (test) phase of the study under both levels of stress. Experiment II was a partial replication of the first study using only loud noise. The interference effect during test trials was greater than in the first study. In addition to these findings, measures of a coronary-prone behavior pattern were related to differential susceptibility to the interference effect under both high stress and moderate stress conditions. These results were interpreted in terms of differing perceptions of threat imposed by lack of environmental control.     

Attributional style and the generality of learned helplessness

According to the logic of the attribution reformulation of learned helplessness, the interaction of two factors influences whether helplessness experienced in one situation will transfer to a new situation. The model predicts that people who exhibit a style of attributing negative outcomes to global factors will show helplessness deficits in new situations that are either similar or dissimilar to the original situation in which they were helpless. In contrast, people who exhibit a style of attributing negative outcomes to only specific factors will show helplessness deficits in situations that are similar, but not dissimilar, to the original situation in which they were helpless. To test these predictions, we conducted two studies in which undergraduates with either a global or specific attributional style for negative outcomes were given one of three pretreatments in the typical helplessness triadic design: controllable bursts of noise, uncontrollable bursts of noise, or no noise. In Experiment 1, students were tested for helplessness deficits in a test situation similar to the pretreatment setting, whereas in Experiment 2, they were tested in a test situation dissimilar to the pretreatment setting. The findings were consistent with predictions of the reformulated helplessness theory.     

Modeling signal features of escape response: effects of cessation conditioning in "learned helplessness" paradigm

Six experiments examined the effects of signaling the termination of inescapable shock (cessation conditioning) or shock-free periods (backward conditioning) on later escape deficits in the learned helplessness paradigm, using rats (Sprague-Dawley and Bantin-Kingman). A cessation signal prevented later performance deficits when highly variable inescapable shock durations were used during pretreatment. The inclusion of short minimum intertrial intervals during pretreatment did not alter the benefits of cessation conditioning but eliminated the protection afforded by a safety signal. The beneficial effects of both cessation and backward signals were eliminated when a single stimulus signaled shock termination and a shock-free period. Finally, a combination of cessation and backward signals was found to be most effective in immunizing against the effects of subsequent unsignaled, inescapable shock on later escape performance. These data suggest that cessation conditioning may be crucial to the prophylactic action of an escape response.     

Modulating effects in learned helplessness of dyadic dominance-submission relations

In this experiment, learned helplessness was studied from an ethological perspective by examining individual differences in social dominance and its influence on the effects of helplessness. Ninety animals were used, 30 randomly selected and 60 selected because of their clear dominance or submission. Each condition (dominant, submissive, and random) was distributed in three subgroups corresponding to the triadic design. The test consisted of an escape/avoidance task. The results showed that the animals in the uncontrollable condition performed worse than those in the controllable and no treatment conditions. Social submission and dominance reduced vulnerability of the subjects against learned helplessness. Submission had a facilitating effect on subsequent learning, independently of whether pretreatment was controllability or uncontrollability. Learned mastery was observed in the submissive condition, because submission benefited the subjects in the controllable condition in comparison with the untreated subjects, and dominance impaired the subjects in the controllable condition.     

Shock preexposure and the reduced effectiveness of shock

In three experiments experience with shock was shown to reduce the effectiveness of shock as a reinforcer or motivator. In Experiment 1 rats were given signaled shock in a box separate from the runway where they were subsequently punished. These rats were less suppressed by shock punishment than rats that had no previous shock experience. In Experiment 2 preshocked rats were less suppressed by punishment and were slower to learn an escape-avoidance response than nonpreshocked rats, whether the preshock was signaled or unsignaled. In Experiment 3 as number of CS-shock pairings increased, fear of the CS decreased as did fear of the context. These results suggest that some central adaptation process produced by experience with shock reduces the effectiveness of shock as a reinforcer whenever shock is used repeatedly. This is independent of other effects, such as context blocking, that can affect responding after shock preexposure.     

Feedback during exposure to inescapable shocks and subsequent shock-escape performance

In two experiments, we assessed the ability of a feedback stimulus during helplessness training to reduce the performance deficits common to inescapable shock. In each experiment, four groups of rats were exposed to either escapable shock (E), inescapable shock with a feedback stimulus following shock termination (Y-FS), inescapable shock with no feedback stimulus (Y-NFS), or no shock (N). The feedback stimulus eliminated the interference effects of inescapable shock when tested with an FR-3 lever press escape task (Experiment 1) or on an FR-1 task with a 3-s delay between the response and shock termination (Experiment 2). These results suggest that stress-induced biochemical changes may mediate the interference effects seen in inescapably shocked rats.