Learned Helplessness Effect Research Articles

Aprendizagem de fuga após estímulos apetitivos incontroláveis

O presente experimento teve por objetivo investigar se estímulos apetitivos não-contingentes (incontroláveis) produzem interferência na aprendizagem de fuga (desamparo aprendido). Ratos foram divididos em três grupos (n = 8), denominados contingente (C), não contingente (NC) e ingênuo (I). Na primeira fase (tratamento), os animais do grupo C receberam reforçamento positivo (água) sob contingência de CRF, FR5 e FR20. A cada reforço liberado a um sujeito do grupo C, era liberada uma gota de água (não-contingente) a um sujeito do grupo NC. Os animais do grupo ingênuo (I) permaneceram no biotério. Na fase seguinte (teste), os animais foram submetidos a choques que poderiam ser desligados em função da resposta de saltar na shuttlebox. Todos os sujeitos aprenderam igualmente a resposta de fuga, independentemente do tratamento prévio recebido. Esses resultados sugerem que estímulos apetitivos incontroláveis não produzem o desamparo aprendido. Discute-se a generalização do efeito entre contextos aversivo e apetitivo.

The effects of learned helplessness on the processing of a persuasive message

The current study examines the effects of exposure to unsolvable problems on the processing of a persuasive message. Participants exposed to either unsolvable failure or no-feedback tasks were presented with one of four versions of an advertisement about a hair shampoo and rated their attitude towards this product. Two aspects of the message were manipulated: the quality of arguments (strong, weak) and the attractiveness of the communicator (attractive, non-attractive). In addition, participants rated their anxiety and the frequency of off-task thoughts during the experiment. Attitude towards the target product of participants in the failure condition was less affected by the argument’s quality and more influenced by communicator attractiveness than the attitude of participants in the no-feedback condition. Participants exposed to failures reported more anxiety and task-related worries than those exposed to no-feedback, and these ratings were found to mediate the effects of failure on the processing of a persuasive message. Results were discussed in terms of Learned Helplessness theories and the Elaboration Likelihood Model.

Escape deficits induced by inescapable shock and metabolic stress are reversed by adenosine receptor antagonists

We examined the relationship between metabolic stress, brain adenosine regulation, and the learned helplessness effect in four experiments in rats. Glucoprivation and metabolic inhibition were induced by treating previously restrained (nonshocked) rats with 2-deoxy- d-glucose (2DG) shortly before escape testing. Experiment 1 demonstrated that 2-deoxy- d-glucose impairs escape performance in a dose-dependent manner. Experimnte 2 showed that 2-deoxy- d-glucose and shock induced escape deficits are completely reversed by peripheral administration of the adenosine receptor antagonist caffeine. This result indicates that both inescapable shock and 2-deoxy- d-glucose result in compensatory adenosine regulation which, in turn, mediates the behavioral impairment. Experiment 3 determined that 8-[ p-sulfophenyl]-theophylline, a peripheral adenosine receptor antagonist, fails to reverse the escape deficit resulting from metabolic stress, whereas centrally acting theophylline does. Experiment 4 showed that the behavioral impairments from both 2-deoxy- d-glucose and inescapable shock are reversed by intracranial ventricular (icv) caffeine treatment. The results of Experiments 3 and 4 indicate that the enhanced adenosine regulation and the ensuing performance deficit resulting from 2-deoxy- d-glucose treatment occurred in the central nervous system. These data are discussed in terms of the metabolic demands of neuronal over-activation during escape testing in inescapably shocked rats and the loss of normal behavioral function due to compensatory adenosine regulation in the brain.

Effects of learned helplessness on brain GABA receptors.

GABA is involved in both clinical depression and in animal models of depression; however, the roles of GABA(A) and GABA(B) receptors in specific brain regions are not clear. Changes in densities of both GABA(A) and GABA(B) receptors have been reported with the learned helplessness animal model of depression and with chronic antidepressant drug treatment. However, some of these findings are discrepant. Thus, we used quantitative autoradiography to study the GABA(A) and GABA(B) receptors in learned helplessness and we used an experimental paradigm that allows non-specific effects of stress to be differentiated from learned helplessness. Densities of GABA binding were measured in prefrontal cortex, septum, hippocampus, hypothalamus and amygdala. In the septum, learned helpless rats had increased densities of GABA(A) receptors and rats that did not become helpless after inescapable stress had decreased GABA(B) receptor densities. No significant group differences of GABA(A) or GABA(B) receptor densities were observed in any other brain region studied. These results suggest a unique role for the septum in modulating GABA in the learned helplessness animal model of depression.

Um olhar crítico sobre o estudo do desamparo aprendido

O desamparo aprendido vem sendo observado numa grande variedade de espécies. Esse artigo mostra as características básicas dos experimentos sobre desamparo aprendido realizados com sujeitos infra-humanos. A análise crítica da maioria desses experimentos revela problemas de procedimento e mensuração do fenômeno, além de pouca precisão nas definições empregadas. É descrito um procedimento modificado, o qual produziu resultados mais precisos quanto à aprendizagem operante em estudo, se comparados com os resultados dos procedimentos convencionais. Sugere-se que a maior precisão dos experimentos sobre desamparo aprendido trará importantes contribuições para a análise do comportamento em geral, e para a investigação do controle aversivo e dos efeitos da não contingência, em particular.

The health practices of homeless women: a causal model.

A theoretical model was developed and tested to explain the effects of learned helplessness, self-esteem, and depression on the health practices of homeless women. Data were collected from a sample of 122 homeless women recruited from six shelters. Structural equation analysis was used to evaluate the model. Analysis revealed a goodness-of-fit index of 98, indicating a good fit of the model with the data. Overall, the variables in the model accounted for 14% to 21% of the variance in the health practices of homeless women.

Inescapable shock-induced potentiation of morphine analgesia.

Exposure to various stressors potentiates nociceptive and nonnociceptive responses to morphine. These phenomena have received little study despite their seeming generality and importance for understanding analgesia and opiate action. The present experiments characterize inescapable shock (IS)-induced potentiation of morphine analgesia. Rats were exposed to IS, equal escapable shocks (ESs), or restraint (control). Potentiation of analgesia (tail-flick [TF] test and hotplate test) was observed only in rats given IS 24 or 48 hr earlier, in agreement with previously reported learned-helplessness effects. Finally, no change in tail temperature or motor function was found that could be inaccurately interpreted as analgesia. The relevance of these findings to stressor-induced enhancement of morphine analgesia and potential substrates of IS effects are discussed.

Aerobic exercise and chocolate as means for reducing learned helplessness

This study tested the effects of 10 min of aerobic exercise, a chocolate snack, or guided imagery as a means of reducing the learned helplessness effects due to the experience of an unsolvable task. It was hypothesized that exposure to unsolvable tasks would lead to a higher level of anxiety, engagement in more task-irrelevant cognitions, and a poorer performance on a solvable test task. Intervention with either chocolate, 10 min of aerobic exercises, or guided imagery would reduce anxiety, reduce task irrelevant cognitions, and prevent performance decrement. Five groups of subjects (n = 100) were tested on a visual search task after experiencing an unsolvable task. Results indicated that the experience of the unsolvable task led to a higher level of anxiety arousal compared to a group that did not experience the unsolvable task. The intervention of either aerobic exercise, chocolate, or guided imagery led to a reduction in anxiety to the level of the control group that had not experienced an unsolvable task. Task-irrelevant cognitions were found to be higher in the classic nonintervention learned helplessness group and in the guided imagery group. The only group to suffer a performance decrement on the test task was the classic learned helplessness group without intervention. All three interventions were found to be equally effective in preventing performance decrement. Results are discussed in terms of an irrelevant defensive cognition/anxiety model as well as in terms of a controllability model.

Learned helplessness inducing foot shock can exacerbate morphine responsiveness

Exposure to inescapable tail shock or foot shock has been shown to produce effects on a number of learning tasks. Tail-shock exposure is also known to influence nociception and morphine reactivity. The present series of experiments investigated the effects of foot shock known to induce learned helplessness effects in our laboratory on the subsequent reactivity to morphine. A first set of experiments investigated the hypoalgesic response to a 4 mg/kg dose morphine over 4 consecutive days following exposure to foot shock. Experiment 1A did not reveal an effect of foot shock on morphine-induced hypoalgesia when testing was conducted in a novel context. In Experiment 1B, we observed an increased hypoalgesic response to morphine when testing was conducted in the shock context. The findings of Experiment 1B were replicated in Experiment 2 and extended to assess the contribution of conditioned fear hypoalgesia to these effects. The possible mechanisms responsible for these findings are discussed.

Opioid nature of learned helplessness and stress-induced analgesia observed without re-exposure to shock

It has been shown that uncontrollable shocks that produce learned helplessness also produce long-term opioid analgesia if th animal is re-exposed to shock immediately before the test. The present study was conducted in order to investigate if this effect can be observed 24h after the uncontrollable shock treatment without re-exposure to shock, and if it is opioid mediated. Long-term analgesia was found in the absence of re-exposure to shock, and was prevented by an i.p. injection of naloxone (10mg/kg) administered 10min before the test. The learned helplessness effect produced by the same shock treatment was prevented by the administration of 10 and 20mg/kg of naloxone 10min before the shuttlebox test, but not by a lower naloxone dose (5mg/kg). These findings suggest that the shock re-exposure requirement proposed in previous studies is not crucial in determining the long-term analgesia, and that both the long-term analgesia and the learned helplessness effect produced by this shock treatment were opioid mediated.

Learned helplessness in chess players: the importance of task similarity and the role of skill.

The effects of noncontingency between subjects' responses and outcomes were examined with respect to treatment-and-posttest similarity and skill in the task. The experimental design consisted of three groups. The first group had to solve chess problems with objective solutions and received veridical feedback; each member of the second group faced problems with no objective solutions, and received the same feedback as the member of the first group he was yoked with, but without any control on it; the control group received a waiting task. It was found at the end of the experiment that the group with unsolvable problems was more depressed than the two other groups. The mid-strength players were the most sensitive to the manipulation, and the weakest players showed little effect of learned helplessness. It was also found that the effects were proportional to the degree of similarity between the treatment and the posttest. The results limit the domain of applicability of the learned-helplessness model.

Enhanced retrieval of unpleasant memory in helpless rats

Several studies in humans have indicated an association between enhanced retrieval of unpleasant events and depressive mood. No analogy has so far been demonstrated in animals, however. The purpose of the present study was to determine the effect of learned helplessness on the retrieval of unpleasant memory in rats. Animals initially exposed to a single unpleasant event in a passive avoidance task were subjected, respectively, to inescapable, escapable, or no shock stress exposure. A retention test conducted 48 hr following stress exposure showed an enhanced performance for the passive avoidance task in rats subjected to inescapable shock stress. This improved performance was not observed in escapable or no shock stress groups. This finding in the learned helplessness condition in rats, is qualitatively similar to that found in humans in depressive mood.

Modulation of [3H]Paroxetine Binding to the 5‐Hydroxytryptamine Uptake Site in an Animal Model of Depression

The effects of learned helplessness on the 5-hydroxytryptamine (5-HT) uptake site were studied in rats using [3H]paroxetine binding. This ligand was chosen because it was demonstrated to label directly the 5-HT uptake site whereas the [3H]imipramine binding site has been demonstrated to be heterogeneous in nature. Moreover, [3H]imipramine appears to bind to a presynaptic recognition site different from the uptake site. Exposure to uncontrollable shock training and testing resulted in an overall increase in [3H]paroxetine binding in all the groups studied [nonhelpless (NLH), learned helpless (LH), spontaneously helpless (SPLH)] as compared to naive controls (NC). However, the increase in [3H]paroxetine binding was significantly higher in the LH and SPLH groups. The maximum number of [3H]paroxetine binding sites in the rat hippocampus was increased significantly in learned helpless rats (LH and SPLH) at day 4 and day 30 after the shock escape test as compared to NC and NLH rats. By contrast, in the rat hypothalamus the maximum number of [3H]paroxetine binding sites was reduced significantly in the LH rats as compared to naive controls and NLH rats during the same time course. There was no change in [3H]paroxetine binding sites in any other brain regions examined in LH, NLH, and NC rats. The results suggest that a hippocampal hypothalamic connection might play a role in the serotonergic mediation of learned helpless behavior.

Differential effects of escapable and inescapable footshock on hippocampal theta activity.

Three groups of rats were exposed to escapable shock, inescapable shock, or no shock using procedures known to induce learned helplessness effects. Twenty-four hours later, hippocampal electroencephalograms were recorded from freely moving subjects. A 5-s probe shock was delivered after 15 min, and recording continued. Frequency analyses revealed no differences between the pretreatment groups during the first recording segment. Immediately after the probe shock, however, trains of immobility-related theta activity were observed in both the escapable-and no-shock groups. No such activity was observed in the inescapable-shock group. Because immobility followed the probe shock in all groups, this relative impairment was not due to differential motor activity. These results offer in vivo support for in vitro findings suggesting that hippocampal activity is sensitive to event contingencies and is involved in stress-induced learning deficits.

Prenatal stress and learned helplessness

Prenatally stressed rats (n = 18) and non-stressed controls (n = 18) were given prior avoidance experience in a Skinner box before being trained in a two-way shuttlebox avoidance task within a standard triadic learned helplessness paradigm. Results indicated that there was no effect of prenatal stress on the acquisition of a lever press in a Skinner box, but that prenatal stress had significant adverse effects on the acquisition of a more difficult two-way shuttlebox avoidance response. The phenomenon of learned helplessness was demonstrated for non-stressed but not for prenatally stressed subjects. The failure to observe the learned helplessness effect in the prenatally stressed subjects appears to have been due to the performance of the prenatally stressed, unshocked control group which displayed slower learning similar to that of the groups exposed to uncontrollable shock.

Burnout in day care workers: The effects of learned helplessness and self-esteem

The study focused on the relationships between selected personality factors and burnout in day care workers. The results indicated that caregivers who experienced emotional exhaustion and depersonalization tended toward lower self-esteem and learned helplessness. Burnout did not, however, include a reduced sense of personal accomplishment in this population.

Learned helplessness in chickens

Evidence of the learned helplessness effect was obtained in 24- to 48-h-old domestic chickens. Twenty-four hours after exposure to escapable shock, inescapable shock, or no shock, subjects were tested on a one-way shuttle task with shock-offset reinforcement. The inescapable shock group showed retarded learning in comparison with other groups. It is argued that the data are difficult to account for in terms of Costello’s (1978) application of the systematic bias in the triadic design.

Predictability and Timing of Self-Report in Learned Helplessness Experiments

An experiment is reported that attempted to assess the contribution of unpredictability to the learned helplessness effect. Contrary to learned helplessness theory, performance deficits resulted from exposure to uncontrollable events only when uncontrollability was also accompanied by unpredictability. Uncontrollable but predictable outcomes did not produce the effect. The experiment also demonstrated that the timing of self-report has an influence on expressed subjective confidence ratings, a finding of some significance in view of the methodology of human helplessness experiments.

The influence of stimulus intensity and motivational differences on learned helplessness deficits

Two experiments are reported which assess the moderating effects on learned helplessness deficits of individual differences in task-specific motivation and expectation of control. In Experiment 1 a neutral stimulus was used and in this case only high motivation subjects displayed helplessness deficits in response to noncontingency training. In addition, high motivation subjects demonstrated greater sensitivity to the noncontingency than did low motivation subjects. However, when an aversive stimulus was used in Experiment 2 the moderating effect of motivational differences was removed and this was accompanied by greater sensitivity to the noncontingency on the part of low motivation subjects. Indeed, the learned helplessness effect in Experiment 2 was more pronounced within the low motivation group. The theoretical significance of these findings is explored and directions for future research are suggested.

Cognitive developmental level, gender, and the development of learned helplessness on mathematical calculation and reasoning tasks

The purposes of the study were, theoretically, to extend learned helplessness findings along the cognitive developmental dimension and, practically, to assess the extent to which learned helplessness in a mathematical calculation task transfers to a mathematical reasoning task. One hundred twenty-eight adolescents were assigned to appropriate treatments in a 2 × 2 × 2 × 2 factorial arrangement (formal vs concrete operational level; male vs female; strategy training vs no training; helplessness treatment vs controls), with percentage correct and incorrect on a calculation and a reasoning task, respectively, as dependent variables. Large and significant main effects occurred for all factors; however, none of the interaction effects was significant. There was thus no differential advantage to persons of either gender, nor to those of the formal reasoning stage of development, in either resisting the effects of learned helplessness or in benefiting from strategy training.