Extinction Of Avoidance Response Research Articles

Comparación de Tres Procedimientos de Extinción de la Evitación Discriminada en Humanos

En la evitación discriminada, una respuesta emitida durante la señal impide la aparición de un estímulo aversivo. La extinción de las respuestas de evitación se ha estudiado como la terminación de la relación instrumental entre la respuesta y el estímulo aversivo. Su compresión ha sido primordial para comprender el mantenimiento de la respuesta de evitación en humanos. Se compararon tres procedimientos de extinción de la respuesta de evitación en humanos. Veintisiete participantes, aprendieron una tarea de evitación discriminada dividida en dos fases: Pavloviana, con apareamientos de dos señales (Estímulo Condicionados; EC 1 y EC2) con un sonido (90 dB, 60 Hz), e Instrumental, donde la respuesta R1 ante el EC1 o la respuesta R2 ante el EC2 evitaba el sonido. Posterior a estas fases, fueron asignados a tres grupos, cada grupo experimentó diferentes procedimientos de extinción; (Estímulo Incondicionado, EI) donde R1 no termino con la señal, pero si con el sonido, (EC) donde R1 termino con la señal, pero no con el sonido, y (EC/EI) donde R1 no termino con ninguno de los estímulos (señal, sonido). En todos los grupos R2 continuó evitando el sonido. Los resultados mostraron que las respuestas de evitación R1 disminuyeron en los grupos EC y EC/EI, y no se extinguieron en el grupo EI. Estos resultados enfatizan la importancia de la terminación de la señal en el mantenimiento del aprendizaje de evitación discriminada.

Direct and Derived Extinction of Avoidance Responses in Equivalence Classes

The present study compared the direct and derived extinction of avoidance responses in equivalence classes. Two classes with four abstract figures in each class (Class 1: A1-B1-C1-D1; Class 2: A2-B2-C2-D2) were first established. An avoidance response that was trained in the presence of one stimulus (B1) was emitted under control of the other stimuli from the same class (C1 and D1). The subjects were then assigned to two different groups (Direct Extinction Group and Derived Extinction Group). Different extinction procedures were implemented for each group. In the Direct Extinction Group, B1 was presented in extinction. In the Derived Extinction Group, C1 was presented in extinction. Finally, the transfer of extinction was evaluated in the presence of the other stimuli from each class. In the Direct Extinction Group, avoidance responses were extinguished for 4 of the 16 participants in the presence of B1. In the Derived Extinction Group, avoidance responses were extinguished for 10 of the 16 participants in the presence of C1. The results indicated that derived extinction occurred more easily than direct extinction. Considering that avoidance responses were extinguished only for a few participants, future studies should implement more efficient procedures to establish avoidance extinction and then evaluate possible differences between derived and direct extinction in the transfer of extinction.

Ventral hippocampus inactivation enhances the extinction of active avoidance responses in the presence of safety signals but leaves discrete trial operant active avoidance performance intact.

The acquisition of active avoidance (AA) behavior is typically aided by the presence of two signals-the warning signal, which predicts the future occurrence of an aversive event (e.g., shocks), and the safety signal, which is presented upon successful avoidance of oncoming shocks. While the warning signal could be conceived to act as a Pavlovian fear cue, and is likely mediated by brain areas that underlie Pavlovian fear cue conditioning, the neural substrates underlying safety signaling are less clear, largely due to the unavailability of AA tasks that are devoid of an explicit warning signal. The present study sought to investigate the role of the ventral hippocampus (VH) in safety signaled AA performance acquired without an explicit warning signal, using a novel discrete trial paradigm. Adult male Long Evans rats were divided into two groups and trained to acquire AA responses with, or without a safety signal. Analysis of the acquisition and stable state performance data revealed that the availability of a safety signal alone did not improve the acquisition or performance of AA responses. Furthermore, post-training, reversible VH inactivation did not impact stable state avoidance behavior. However, extinction of avoidance responses was facilitated in the group trained with a safety signal, and this effect was further potentiated by VH inactivation. Additional elevated plus maze (EPM), light-dark box, and locomotor tests demonstrated that VH inactivation reduced anxiety without affecting locomotor activity. Taken together, these results demonstrate the importance of VH in the extinction of persistent pathological avoidance behavior when safety is signaled.

Altered activity of the medial prefrontal cortex and amygdala during acquisition and extinction of an active avoidance task.

Altered medial prefrontal cortex (mPFC) and amygdala function is associated with anxiety-related disorders. While the mPFC-amygdala pathway has a clear role in fear conditioning, these structures are also involved in active avoidance. Given that avoidance perseveration represents a core symptom of anxiety disorders, the neural substrate of avoidance, especially its extinction, requires better understanding. The present study was designed to investigate the activity, particularly, inhibitory neuronal activity in mPFC and amygdala during acquisition and extinction of lever-press avoidance in rats. Neural activity was examined in the mPFC, intercalated cell clusters (ITCs) lateral (LA), basal (BA) and central (CeA) amygdala, at various time points during acquisition and extinction, using induction of the immediate early gene product, c-Fos. Neural activity was greater in the mPFC, LA, BA, and ITC during the extinction phase as compared to the acquisition phase. In contrast, the CeA was the only region that was more activated during acquisition than during extinction. Our results indicate inhibitory neurons are more activated during late phase of acquisition and extinction in the mPFC and LA, suggesting the dynamic involvement of inhibitory circuits in the development and extinction of avoidance response. Together, these data start to identify the key brain regions important in active avoidance behavior, areas that could be associated with avoidance perseveration in anxiety disorders.

D-Cycloserine acts via increasing the GluN1 protein expressions in the frontal cortex and decreases the avoidance and risk assessment behaviors in a rat traumatic stress model

d-cycloserine (DCS), an FDA approved anti-tuberculosis drug has extensively been studied for its cognitive enhancer effects in psychiatric disorders. DCS may enhance the effects of fear extinction trainings in animals during exposure therapy and hence we investigated the effects of DCS on distinct behavioral parameters in a predator odor stress model and tested the optimal duration for repeated daily administrations of the agent.Cat fur odor blocks were used to produce stress and avoidance and risk assessment behavioral parameters were used where DCS or saline were used as treatments in adjunct to extinction trainings.We observed that DCS facilitated extinction training by providing further extinction of avoidance responses, risk assessment behaviors and increased the contact with the cue in a setting where DCS was administered before extinction trainings for 3 days without producing a significant tolerance. In amygdala and hippocampus, GluN1 protein expressions decreased 72h after the fear conditioning in the traumatic stress group suggesting a possible down-regulation of NMDARs. We observed that extinction learning increased GluN1 proteins both in the amygdaloid complex and the dorsal hippocampus of the rats receiving extinction training or extinction training with DCS.Our findings also indicate that DCS with extinction training increased GluN1 protein levels in the frontal cortex. We may suggest that action of DCS relies on enhancement of the consolidation of fear extinction in the frontal cortex.

Pinealectomy blocks modulation of active avoidance by central vasopressin application in rats

The inter-relationship between central vasopressin and the pineal gland in the modulation of active avoidance behavior was investigated. In sham-operated (SO) rats, intracerebroventricular (i.c.v) application of 10 ng arginine vasopressin (AVP) after both the last acquisition and the first extinction trials prolonged the extinction of the active avoidance response; application of 50 ng of the V1 antagonist, d(CH2)5Tyr(Me)AVP (AAVP) was without effect in both experiments. In contrast to the SO in pinealectomized (PX) rats neither AVP nor AAVP influenced the extinction of the avoidance response. Intraseptal infusion of 200 pg AVP or 5 ng AAVP either after the last acquisition or the first extinction trial was without effect in both SO and PX rats. Comparison of the acquisition trials revealed no differences between SO and PX rats.

Vasopressin's effects on acquisition and extinction of conditioned avoidance response to smoking

Lysine-8-vasopressin (LVP) 5 I.U. or NaCl was administered intranasally daily for 5 days in a double blind study to 14 women and 7 men volunteers, 30 minutes prior to aversive conditioning sessions designed to assist them to stop smoking. Subjects were asked to record the number of urges to smoke, the strength of their strongest urge to smoke and the number of cigarettes smoked on a daily basis. Adequate data was obtained from 17 subjects for the Lead-in (pretreatment) week and for the Treatment week. Of these, 10 continued to supply sufficient responses through the sixth week of follow-up. During the week of aversive conditioning those subjects receiving LVP smoked significantly fewer cigarettes than the saline treatment group ( p<0.01). During the Follow-up period the LVP group had significantly more urges to smoke than the saline group ( p<0.01). The LVP group also smoked significantly more cigarettes than the saline group 4 weeks ( p<0.05) and 6 weeks (0.01) after the Treatment week. LVP was associated with a facilitation of the acquisition of the avoidance response to smoking followed by an apparent acceleration of the extinction of the avoidance response compared to saline.

Effects of desglycinamide-lysine vasopressin on a conditioned taste aversion in rats

Vasopressin and other pituitary peptides have been shown to increase resistance to extinction of active and passive shock-avoidance responses. Both paradigms use external cues as warning and punishing stimuli. The present work asked if a variant of vasopressin would have a similar effect on conditioned taste aversions (CTA), which use internal cues as warning and punishing stimuli. Eight groups of rats were defined by factorial combination of Pretreatment during Neophobia and Conditioning (vasopressin vs saline), UCS during Conditioning (pairing saccharin-flavored water with injections of lithium chloride or saline), and Pretreatment during Extinction (vasopressin vs saline). Rats given three saccharin-lithium pairings developed strong aversions. Of the rats with CTAs, those given vasopressin during conditioning, extinction, or both showed increased resistance to extinction on the last four of eight extinction days. Vasopressin had no other effect on drinking of saccharin. Vasopressin thus appears to enhance resistance to extinction of avoidance responses in both external and internal milieus.

Dissociative effects of different types and amounts of nonreinforced CS exposure on avoidance extinction and the CER

Two experiments examined the effectiveness of two amounts of flooding or response-prevention on hastening avoidance response extinction and on reducing CS-produced suppression of bar-pressing for food. In Experiment 1, 20 and 30 flooding trials were both shown to be effective in hastening the extinction of a well-learned shuttlebox avoidance response. In Experiment 2, rats trained under comparable conditions to those in Experiment 1 were tested following flooding for the CER in a different apparatus. The results indicated that 30, but not 20, flooding trials were sufficient to reduce the CER. In each experiment the results of additional control groups equated with the flooded groups for nonreinforced CS exposure also revealed a dissociation between the effectiveness of this CS time control procedure in hastening avoidance response extinction and in reducing the CER. Further comparisons showed that although 30 flooding trials did reduce the CER, the same total duration of nonreinforced CS Exposure in the form of avoidance extinction trials did not. Thus the context in which CS exposure occurs may affect the dynamics of extinction of the CER. The experiments are discussed in the broader context of dissociation of various indices of fear in humans.

Some further tests of the brief confinement effect and the SSDR account of flooding

Although brief confinement in novel or fearful places may occasionally produce flooding-like effects with regard to hastening avoidance response extinction, the results of the three experiments reported here indicate that this is not as robust a phenomenon as is flooding. Experiments 1 and 2 found that any tendency for a brief confinement effect to occur is likely to result from the use of a procedure where extinction is started on the grid floor as opposed to on the ledge of a jump-up box. Experiment 3 found no evidence at all that confinement in either a novel or a fearful place can hasten the extinction of a more well-learned jump-up response than that studied in previous experiments, even when the grids extinction procedure was used. Overall these results do not support the SSDR account of flooding, which has derived its chief support from experiments demonstrating a brief confinement effect.

Modification of conditioned behavior of rats by neurohypophyseal hormones and analogues

Vasopressin and other neurohypophyseal peptides affect various processes related to memory and/or learning. A single subcutaneous injection of vasopressin increases resistance to extinction of a pole-jumping avoidance response in rat. This test system has been applied in an attempt to relate structural aspects of neurohypophyseal peptides, analogues, and derivatives with truncated sequences to their effects on conditioned behavior. Thus far it can be concluded that there are more stringent requirements on certain residues in the 20-member covalent ring than in positions 8 and 9 of the linear peptide portion for neurohypophyseal hormones to be active. Critical are the contributions of residues in positions 2, 3, and 5; these results are reminiscent of those from conformation-activity correlations of the endocrine effects of neurohypophyseal hormones, in which the side chain of the residue in position 3 is critical for receptor binding and the side chains of residues in positions 2 and 5 are key for the activation of the receptor. Chemical modifications in position 4 yield analogues that are active and inactive in increasing the resistance to extinction of the avoidance response, depending on the particular structural substitution, similar to results from structure-activity studies of the endocrine activities of neurohypophyseal hormones. Because behavioral activities of vasopressin are more tolerant than endocrine activities to modifications of the hormone in positions 8 and 9, analogues with the most striking dissociation of potencies in learned behavior and endocrine responses are expected to be those with sequence alterations in the linear peptide portion. Peptides with linear part sequences of neurohypophyseal hormones showed little or no activity. The results obtained in this structure-activity study are compared with those of an earlier study in which the ability of various neurohypophyseal peptides to attenuate puromycin-induced amnesia in mice was evaluated.

One session of flooding as treatment for conditioned avoidance responding in humans: effect of individualization of treatment duration.

An avoidance response was conditioned to three stimuli (tone, vibrator, and light) presented in serial order. Following conditioning, each group of subjects underwent a different treatment procedure. Group 1 received a completely individualized flooding procedure distributed over multiple trials. Duration of the conditioned stimulus presentations was individualized by making them contingent upon termination of conditioned suppression, and duration of the treatment session by termination of conditioned avoidance. The Group 2 flooding procedure was completely non-individualized, massed into one trial and yoked to Group 1 to control for the amount of exposure to each of the conditioned stimuli and the duration of treatment sessions. Group 3 experienced non-individualized duration of treatment, individualized conditioned stimulus presentations distributed over trials and controlled for the duration of the treatment session and the distribution of trials. Analysis indicated that individualized duration of the flooding session utilizing a measure of anxiety dissipation significantly hastened the extinction of avoidance responses. Implications for the effective practice of implosive therapy were discussed.

The effects of overtraining on flooding of jump-up and shuttlebox avoidance responses

Two experiments are reported which test the effects of overtraining (2, 4 or 6 days) on the efficacy of flooding (response-prevention) in hastening the extinction of jump-up and two-way shuttlebox avoidance responses. In the jump-up box, overtraining reduces the effectiveness of flooding in two ways: Rats trained for 6 days and given a flooding treatment are more resistant to extinction than rats trained for only 2 or 4 days and given a flooding treatment. By contrast, rats trained for 6 days and given a control treatment are less resistant to extinction than control rats trained for 2 or 4 days. In the shuttlebox, overtraining neither reduces the effectiveness of flooding in hastening avoidance response extinction, nor reduces the resistance to extinction of control animals. Implications of these different effects of overtraining on jump-up and two-way shuttlebox responses are discussed.

The Effects of Manipulation of the CS and Variations in the Duration of Response Prevention on Extinction of Avoidance Responses

Rats were trained to avoid 0.5 mA shock and, following learning, were divided into two groups ‐ control and experimental. Following acquisition trials, the control animals were left in the shuttle box for 5 min and the experimental animals were removed from the shuttle box and placed in a plastic pail. The CS was presented continuously for 5 min. The rats were then returned to the shuttle box and extinction trials began. The results showed that response prevention was ineffective when it occurred in the presence of the discrete CS. After learning to avoid 0.5 mA shock, animals in the second experiment were divided into the following four groups: controls and three groups which received response prevention for 10 sec, 3 min and 5 min, respectively. The results showed that there was no significant difference between the groups. Clinical implications of the results of both experiments are discussed.

Effects of flooding an irrelevant response on the extinction of avoidance responses.

Effects of flooding an irrelevant response on the extinction of avoidance responses.

Dorsal hippocampus: A site of action of neuropeptides on avoidance behavior?

Vasopressin and ACTH 4–10 induce a dose dependent long-term, respectively short-term inhibition of extinction of a pole jumping avoidance response in animals with sham lesions in the antero-dorsal hippocampus. Small lesions, causing a restricted damage in this area of the brain, partly inhibit the behavioral effect of vasopressin. Extensive lesions in the antero-dorsal hippocampus completely prevent the inhibitory effects of vasopressin and of ACTH 4–10 on extinction of the avoidance response. The extensive lesions in the dorsal hippocampus complex do not interfere with the rate of extinction, but acquisition of the response is retarded. These observations do not allow the conclusion that the hippocampal complex is the locus of action of neuropeptides in relation to avoidance behavior; it is more likely that this brain region is but one site of behavioral action of these hormones, and that the limbic system needs to be intact to permit the neuropeptides to exert their behavioral effects.

Effects of catecholamines on behavior.

The potential for at least partial reversible transition of aggression- and anxiety-type symptomatology suggested searching for a potential biochemical link between subcellular mechanisms involved in the execution of aggression and anxiety. The effects of norepinephrine combined with dopamine and of epinephrine on these two types of behavior were tested. Responses to foot-shock were used to test aggression, extinction of avoidance response was used to test anxiety-type behavior. The results suggested that one of the possible links between the intracerebral processes responsible for execution of aggression- and anxiety-type behaviors is transmethylation of norepinephrine and/or dopamine to epinephrine.

Effects of flooding an irrelevant response on the extinction of avoidance responses.

Effects of flooding an irrelevant response on the extinction of avoidance responses.

An experimental analysis of exposure to “explicit” heterosexual stimuli as an effective variable in changing arousal patterns of homosexuals

The effect of exposure to explicit heterosexual stimuli on heterosexual arousal was experimentally analyzed in four homosexuals in a series of single case experimental designs. Each subject was sequentially exposed to films of female or male sexual content under positive therapeutic instructions. Penile response to female slides in separate measurement sessions increased during exposure to the female film, decreased during exposure to the male film, and increased once again when the female film was reinstated. The increase in penile response to female stimuli was paralleled in many instances by changes in masturbatory fantasy, reports of arousal and heterosexual behavior outside the laboratory. Increasing heterosexual arousal had little effect on homosexual responsivity. Results are discussed in terms of exposure facilitating extinction of avoidance responses toward females and providing new sexual fantasy content.

Socially facilitated extinction of a conditioned avoidance response

In the present experiment, rats were trained to avoid shock by crossing to the adjacent compartment in a one-way avoidance box. Extinction of this response was then carried out in the presence of: (1) three active rats, the social facilitators (SF) which had been trained not to avoid the conditional stimuli; (2) three completely anesthetized rats, the anesthetized social facilitators (ASF); (3) three objects (O); and (4) alone (C). Groups SF and ASF extinguished significantly faster than Groups O and C; however, there were no significant differences observed between Groups O and C or between Groups SF and ASF. It was concluded that anesthetized rats were as effective as the active, nonanesthetized rats in facilitating extinction of the avoidance response. *We would like to thank Joseph Ternes for his comments and suggestions, for sponsoring and for taking editorial responsibility for this paper. This study was submitted by the first author in partial fulfillment of the requirements for a degree of Master of Arts, Department of Psychology, University of Puerto Rico.