Shuttle-box versus -maze avoidance: Value of multiple response measures in interpreting active-avoidance performance of rats.

Compared active-avoidance performance in a shuttle box to avoidance performance in a -maze brightness discrimination task for 18 male albino rats from each of 4 strains: F344, CDF, Holtzman, and ZM. 2 acquisition sessions were given with procedural parameters the same in both testing situations. There were marked differences among the strains on the avoidance measure in both the shuttle box and the maze. Analysis of other response measures available in the -maze situation (correct discriminations, incorrect avoidances, incorrect escapes) suggests that the differences among the strains in avoidance behavior were due to strain-specific differences in unconditioned response to shock and cannot be attributed to strain-related differences in ability to form stimulus-response associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Species-specific behavior and acquisition of avoidance behavior in rats.

Studied thigmotaxis (i.e., the tendency to run in contact with objects) in 3 experiments with a total of 54 female Long-Evans rats. Exp. I indicated that Ss became more thigmotactic and immobile following shock compared with no-shock conditions. Exp. II demonstrated that when 2 groups were required to make comparable, but different, avoidance responses, the group whose avoidance response was more closely related to the S's species-specific defensive behavior was acquired at a faster rate. The 3rd experiment indicated that the differences in the acquisition of the avoidance responses in Exp. II were not due to differences in operant rates for the 2 responses per se, since acquisition of these same 2 responses was similar under appetitive motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strain differences in avoidance conditioning as a function of the classical CS-US contingency.

Examined rates of shuttle box avoidance responding in 3 strains of rats as a function of classical and instrumental contingencies in 2 experiments. Ss were a total of 126 female albino Fischer, Lewis, and Long-Evans rats. In Exp I, during classical conditioned-stimulus-unconditioned-stimulus (CS-UCS) pairings in the absence of an avoidance contingency, there were large differences between the 3 strains in rates of anticipatory responding to the CS. The same pattern of differences was observed in Exp II when the avoidance contingency was added. None of the instrumental contingencies of CS termination, UCS termination, or the avoidance contingency differentially affected the strains. Classically elicited anticipatory responses and their compatibility with the required avoidance response were viewed as central factors in both the acquisition and maintenance of skeletal avoidance responses. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of exposure to conditioned stimulus and control of its termination in the extinction of avoidance behavior.

Describes 2 experiments in which, following signaled shuttle box avoidance training, a total of 52 female Fischer344 rats were exposed to the conditioned stimulus (CS) during no-shock treatment trials and subsequently tested during extinction trials in which shock was also absent. In Exp I, Ss that could control the termination of the CS during treatment responded significantly more often during extinction than yoked partners that received the same pattern and duration of CS exposure but could not control its termination. Exp II revealed that the probability of responding during extinction was a decreasing function of the duration of CS exposure during treatment. Thus, in the absence of shock, both lack of control over CS termination and increasing CS exposure each independently facilitated the weakening of well-established avoidance responses. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction among genotype, unconditioned stimulus, d-amphetamine, and one-way avoidance behavior of rats.

In the genetic analysis of avoidance learning, questions relating to the generality to other avoidance behaviors and the role of motivation were investigated in 61 RHA/Lu and 61 RLA/Lu rats. Significant differences were found in 1-way avoidance behavior of the strains selectively bred for 2-way active avoidance. In 6 experiments, these differences in 1-way avoidance either disappeared or were minimized to a great extent under the effects of dextroamphetamine. The experimental manipulation of motivation (i.e., unconditioned stimulus shock level equivalent to the unconditioned flinch, jump, and fleeing response measures) accounted for only part of the variation in avoidance learning of these strains. Results are discussed in the terms of inverted-–U arousal function and quantitative genetics. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extinction of an avoidance response following response prevention: Some parametric investigations.

Conducted 2 experiments to investigate parameters influencing the efficacy of response prevention. In Exp. I, with 44 female hooded rats, the amount of response prevention given to Ss who had learned to avoid electric shock in an automated apparatus was systematically varied. Increasing the duration of response prevention increased its effectiveness in hastening extinction. In Exp. II, with 31 Ss, the intensity of shock used in avoidance learning was parametrically varied. More intense shock diminished the efficacy of a fixed amount of response prevention. In both experiments, S's spontaneous behavior during response prevention was systematically recorded. The cessation of fear behavior and the occurrence of relaxation during response prevention were found to predict accurately the successful extinction of the avoidance response. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic differences in avoidance learning by Rattus norvegicus: Escape/avoidance responding, sensitivity to electric shock, discrimination learning, and open-field behavior.

Studied the behaviors of Long-Evans rats selectively bred for either good (SHA line) or poor (SLA line) shuttle box avoidance learning. The results of Exp I indicated that the phenotypic difference in avoidance learning was not associated with differences in speed of escape or avoidance responding. Differences between the lines in frequency of intertrial responses (ITRs), which appeared during training but not during pretest, suggest that ITRs in Ss of the low-avoidance SLA line were more suppressed by electric shock than in Ss of the high-avoidance SHA line. This result suggests that SLA Ss may be more emotionally responsive than SHA Ss. Exp II demonstrated that the Ss of the 2 lines did not differ in absolute sensitivity to electric shock, and Exp III showed that the poor performance of the SLA line was not due to an inability to learn. Ss also provided evidence that the poor avoidance learning by SLA Ss was due to their emotional reactivity. Observations of open-field behavior in Exp IV were consistent with this hypothesis. It is concluded that the major consistent correlate of the phenotypic difference in avoidance learning was greater emotionality or emotional reactivity in SLA than in SHA Ss. (57 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of avoidance in aggressive responses to attack and no attack.

In 2 experiments male Ss interacted with a presumed opponent in a task that permitted the 2 participants to exchange various intensities of shock, including a zero intensity. The Ss' responses were considered separately following attack (receipt of shock) and no attack (no receipt of shock). For responses following no attack, the Ss' aggressive behavior varied with their ability to avoid further shock. Relative to controls, Ss who could avoid further shock by nonaggression (Exp I, 40 college students) were less aggressive. Those who could avoid shock by being very aggressive (Exp II, 20 college students) were more aggressive than controls. Aggressive responses following attack, however, were not influenced by avoidance contingencies. The ability to avoid further shocks apparently influenced males' aggressive responses in the absence of attack but failed to influence males' aggressive responses to attack. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of variations in stimulus similarity and response requirement during pre-shock upon subsequent one-way active avoidance learning.

Describes 2 experiments with 48 adult male Holtzman albino rats, which examine further the stimulus and response conditions under which prior fear conditioning facilitates 1-way active avoidance acquisition. Fear in both experiments was established during passive avoidance training by administering a single 2-sec shock following a cross-through response from a white to a black compartment. Subsequent active avoidance acquisition was facilitated in Exp. I even though the response requirements of the 2 tasks were incompatible. In Exp. II reversed stimulus-shock arrangements existed in the 2 learning tasks. Facilitation of avoidance acquisition as a function of the prior task was again obtained. (French summary) (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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Fischer 344 (F344) and Lewis (LEW) rats show considerable neuroanatomical and neurophysiological differences within the mesolimbic dopamine system. The aim of our experiments was to study the functional correlates of such differences by examining open-field behavior and the sensitivity towards the psychostimulant and rewarding effects of amphetamine in male and female, F344 and LEW rats. In addition, the consequences of short versus extended habituation to open-field testing on amphetamine locomotion in these two rat strains was assessed. LEW but not F344 rats irrespective of gender showed between-session habituation of open-field activity. Amphetamine-induced locomotion was higher in F344 compared to LEW rats and in females compared to male rats. In addition, extended habituation increased the locomotor effects of amphetamine. The rewarding effects of amphetamine as measured by the conditioned place preference test were more pronounced in F344 than in LEW rats. Our results suggest that the two rat strains differed in their behavioral response to mild stress and to amphetamine and that these differences may depend upon differences within the mesolimbic dopamine system.     

Behavioral impairments related to cognitive dysfunction in the autoimmune New Zealand black mouse.

Compared the sensorimotor competence and performance of 7–20 mo old male New Zealand Black (NZB) mice and CFW mice on tasks requiring learning and memory, including passive shock avoidance, taste avoidance, tailflick, rotorod, locomotor activity, reflex evaluation, auditory startle response, shock-induced startle response, and active shock avoidance. Results demonstrate that NZBs showed pronounced deficits in performance of passive and active shock avoidance responses. These deficits could not be accounted for by the slight sensorimotor disadvantage of NZBs relative to CFWs. No difference between the 2 mouse strains was seen in passive avoidance behavior at 1.5 mo of age. It is concluded that NZBs display a behavioral deficit related to cognitive dysfunction and that autoimmune mechanisms may be involved in the etiology of this deficit. It is suggested that such behavioral disturbances produced by an autoimmune mechanism may have relevance for the neurological declines observed in aging since the incidence of autoimmune disorders increases markedly in old age. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response prevention (flooding) in rats: The effects of restricting exploration during flooding and of massed vs distributed flooding.

Conducted 2 experiments with 33 and 60 female hooded rats to determine ways of decreasing or increasing the efficacy of response prevention (flooding). In Exp. I, Ss were trained to avoid electric shock and following learning some groups were given the response-prevention treatment. (Response prevention consisted of thwarting the avoidance response while forcing Ss to remain in the presence of the feared stimuli.) Mechanically confining the Ss during response prevention (interfering with the occurrence of spontaneous exploration and locomotion) decreased the efficacy of the treatment in leading to extinction of the avoidance response. In Exp. II, Ss were trained to avoid intense shock and then were given response prevention in either 1 single, long-duration session or in several shorter sessions distributed over days (massed vs. distributed flooding). Results indicate that distributed response prevention was more effective than massed response prevention. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factors modulating the effects of teleost telencephalon ablation on retention, relearning, and extinction of instrumental avoidance behavior.

Examined the nature of avoidance behavior in a total of 65 goldfish (Carassius auratus) in 2 experiments. In Exp I, a master/yoked design was used to determine the degree to which Pavlovian conditioning would generate acquisition of a shuttle response by 24 Ss. Results indicate that the sequence of signal-shock pairings experienced by the avoidance Ss was not in this situation sufficient to explain the development of the instrumental avoidance responding. In Exp II, the effects of 3 variables on the retention and extinction of the avoidance response were studied. First, unilateral lesions of the telencephalon produced a transient deficit from which the Ss recovered to normal levels. Retention of avoidance response after bilateral telencephalon ablation was impaired and never fully recovered with additional training. Second, this deficit was reduced under higher intensities of electric shock. Overtraining on the task before the ablation had only a nonsignificant enhancing effect on retention levels. Extinction was always poorer following ablation, independent of the type of ablation, intensity of shock, degree of overtraining, and terminal retention level of performance. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of genotype and postnatal experiences on activity, avoidance, shock threshold, and open-field behavior of rats.

Studied the effects of postnatal experience in 6 experiments on the activity, avoidance, shock threshold, and open-field behavior of 91 selectively-bred Ss from high-avoidance (RHA/Lu) strains and 93 from low-avoidance (RLA/Lu) strains. Significant differences were found between postnatal experiences in shuttle box activity, but strain differences were not significant. The high-avoidance Ss acquired avoidance learning significantly faster and had lower shock thresholds than the low-avoidance Ss. However, postnatal experience had significant effects on avoidance and shock threshold only in the high-avoidance Ss. No significant strain differences were found in open-field behavior, and the postnatal experience effects showed only higher order significant interactions. Results are discussed in the framework of quantitative genetics and a direct-action hypothesis of postnatal experience. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Safety training: The elimination of avoidance-motivated aggression in dogs.

In Exp I, retrospective data of 92 cases on dangerously aggressive companion dogs demonstrated the avoidance nature of the aggressive response and its intractability to established counterconditioning treatments. In Exp II, safety training, a modified avoidance-learning procedure, resulted in complete and permanent elimination of aggression in all 36 dogs tested. In addition, it produced extinction-resistant prosocial avoidance responses, significant increases in the dogs' emotional stability, an avoidance-learning and safety acquisition response set, and improvements in measures of the dog's "carriage." Exp III (18 Ss) showed how effective safety training is when compared with other behavior modification techniques that, in theory, should have an impact on avoidance-motivated aggression. Exp IV (16 Ss) demonstrated the importance of using the conditioned safety cue as a positive reinforcement. The relationship of avoidance-motivated aggression to other forms of aggression is discussed, the theoretical concepts of behavioral balance and an avoidance-learning set are presented, and suggestions to improve the effectiveness of counterconditioning for human avoidance-motivated pathologies are offered. (90 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impairment of cliff avoidance reaction induced by subchronic methamphetamine administration and restraint stress: comparison between two inbred strains of rats

1. The effects of subchronic methamphetamine (MAP) treatment and restraint stress on the behavioral sensitization in stereotypy (stereotypy sensitization) and cliff avoidance reaction (CAR) were examined in two inbred strains of male rats; Fischer 344/N (F344), and Lewis/N (LEW). 2. In experiment 1, the animals received 4 mg/kg/day MAP for 30 days. LEW rats developed stereotypy sensitization earlier than F344 rats. However, both strains plateaued at the same stereotypy rating score. Furthermore, F344 rats were susceptible to CAR impairment as a result of MAP treatment, whereas LEW rats were not. 3. In experiment 2, the animals were exposed to daily restraint stress of 2hr for 4 weeks. MAP was administered (4mg/kg) 7 days after the last treatment day. Repeated restraint stress induced almost the same degree of stereotypy sensitization in both strains. F344 rats were susceptible to CAR impairment induced by repeated stress, whereas LEW rats were not. 4. The effects of psychostimulant and stressors appear to be similar not only with respect to stereotypy sensitization but also CAR impairment. Differences in MAP- or stress-induced CAR impairment between the two inbred strains may be genetically linked and may be involved in the development of psychotic behavior.     

Effects of response restriction during exposure to inescapable shock upon subsequent one-way and shuttle-avoidance performance in rats.

Investigated the effects of signaled inescapable shock on subsequent avoidance performance in 3 experiments with male Holtzman rats (N = 188). Exp I indicated that prior shock exposure (PSE) facilitated 1-way and shuttle avoidance. When Ss were preshocked in a harness so that free mobility was not possible, the facilitative effects of PSE on shuttle, but not 1-way avoidance performance, were largely reduced. Exp II indicated that activity during CS periods following PSE was greater among unrestrained than restrained Ss. Exp III showed that immobilization via injection of succinylcholine chloride did not affect the facilitative effects of PSE relative to that of Ss preshocked in a harness. Results are interpreted in terms of response repertoire changes produced by PSE in conjunction with the response requirement of the avoidance task. (French summary) (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Active avoidance behavior following archistriatal lesions in pigeons.

Exp I examined the performance of 10 pigeons, 5 with bilateral medial archistriatal lesions and 5 sham-operated controls, in the acquisition and maintenance of a discrete-trial treadle-press avoidance response. The archistriatal Ss had longer response latencies and never attained the level of performance achieved by the controls. In Exp II, 8 pigeons learned a treadle-press response to avoid or escape shock on a signaled free-operant schedule. After 17 daily sessions, 4 Ss received bilateral lesions in the medial archistiatum, and 4 received control lesions in the neostriatum. After recovery from surgery, all Ss were returned to the experimental procedure. Avoidance of those Ss with archistriatal lesions was impaired relative to the postoperative level while that of the control group was unchanged. Results are interpreted in the light of earlier experiments showing reduced escape and avoidance behavior both in other avian species and in mammals with lesions in the amygdala, to which the archistriatum is considered homologous. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term retention of avoidance learning by immature and adult rats as a function of environmental enrichment.

Taught 32 23-day-old female Sprague-Dawley albino rats active or passive avoidance. 32 controls received equivalent handling and shock in a different apparatus. Both groups were then exposed to an enriched or standard laboratory environment for 60 days prior to a retention test. Environmental enrichment resulted in greater forgetting of active avoidance. The lack of initial latency differences between control groups together with other indices of activity suggested that the differential forgetting was due to memorial effects rather than environmentally induced activity differences. Exp. II with 26 Ss indicated that environmental enrichment resulted in greater forgetting for both weanlings and adults, implicating extraexperimental interference as a general source of incomplete retention by the rat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-dependent improvement in passive avoidance learning of the young chick: Cholinergic mediation?

Studied cholinergic mediation of the age-dependent improvement in response suppression of the young chick by determining the performance of 144 Vantress?×?Arbor Acre 4-day-old chicks, pretreated with scopolamine (SCO), during passive avoidance (PA) and extinction testing. In Exp I, Ss were trained to keypeck for heat reward (prepunishment training), and then tested for PA learning under immediate, 2-sec-delayed, or no shock condition. Half of the Ss in each condition received saline injections before prepunishment training and .5 mg/kg SCO injections after training. The rest received .5 mg/kg SCO injections both before and after training. For Ss in both SCO groups, delaying shock onset resulted in significantly less response suppression than immediate response-contingent shock. In Exp II, 4-day-old Ss injected with saline or SCO were trained to keypeck for heat reward and then tested for resistance to extinction under response-contingent shock or nonshock conditions. Punishment decreased the number of extinction responses for both saline and SCO groups. Results indicte that the age-dependent improvement in response suppression of the young chick cannot be explained solely by a significant increase in central cholinergic functioning. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)