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1.
In 2 experiments using the rabbit conditioned eyeblink preparation, the conditions under which a Pavlovian conditioned stimulus/stimuli (CS) potentiates or diminishes the unconditioned response (UCR) were examined. Results indicate that, after discrimination training (CS+ vs CS–), the CS+ diminished UCR amplitude at the training interstimulus interval (ISI). When CS+ trials were segregated into trials on which a conditioned response (CR) did or did not occur, the CS+ diminished the UCR when it elicited a CR, but not when a CR failed to occur. When the CS-unconditioned stimulus (UCS) interval was lengthened to 10 sec, the CS+ reliably potentiated the eyeblink UCR on CR trials but did not potentiate responding on trials on which a CR was absent. Results are discussed in terms of the modulatory effects and temporal properties of conditioned fear and an associatively produced decrement in UCS processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Swain Rodney A.; Shinkman Paul G.; Nordholm Alan F.; Thompson Richard F. 《Canadian Metallurgical Quarterly》1992,106(5):739
Implanted rabbits with chronic stimulating electrodes in white matter underlying lobule HVI of the cerebellar cortex. Stimulation elicited movements of the face or neck and, when paired with a tone CS, produced learning comparable to that seen with peripheral unconditioned stimulus/stimuli (UCS). CS-alone trials produced extinction. Reinstatement of paired trials produced reacquisition with savings. Additional groups received either explicitly or randomly unpaired CS–UCS trials before paired conditioning. Low-frequency responding during these sessions indicated that the paired training results were associative and not due to pseudoconditioning or sensitization. Explicitly unpaired sessions retarded learning on subsequent paired trials compared with groups that received either randomly unpaired or no CS–UCS preexposure. These results are interpreted in terms of the role of the cerebellum and associated pathways in classical conditioning of motor responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
Injected pentobarbital (PB) into rats 20 min after they were placed in an apparatus where heart rates were recorded. Amphetamine was injected after they were removed from the apparatus 29–30 min later. A Pavlovian conditioned response (CR) began after 3 or 4 trials in the form of a failure of conditioned Ss to show the same decline in heart rate obtained in controls after the PB injection. On later trials, the amphetamine was not injected until 50 min after the PB, and the CR was most obvious during the period 30–50 min after the PB injection. The pharmacological effects of PB were necessary for conditioning because the CR was not obtained (a) when normal saline was substituted for the PB after successful conditioning or (b) when saline was used instead of PB throughout. Because of the speed and effectiveness of the conditioning, we believe the mechanism responsible for it has homeostatic regulation as its natural role. It was puzzling that environmental cues seemed to have a role in the conditioned stimulus complex, because conditioning was not apparent when the drug–drug pairings were administered in the home cage. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
Rosen Jeffrey B.; West Elizabeth A.; Donley Melanie P. 《Canadian Metallurgical Quarterly》2006,120(2):290
Predator odors induce unconditioned fear in rats; however, the synthetic predator odor 2,4,5-trimethylthiazoline (TMT) either elicits robust fear behavior (e.g., freezing) or no fear responses at all. The authors investigated whether this is due to the use of different outbred rat strains. TMT induced robust freezing in Sprague-Dawley and Long-Evans rats but not in Wistar rats. All 3 strains avoided TMT, but Wistar rats were less sensitive to TMT. Wistar rats are capable of freezing; all 3 strains displayed the same amount of odor-cue conditioned freezing. Thus, TMT is a robust unconditioned fear stimulus in rats, and prior negative results from other laboratories were due to the choice of a rat strain (Wistar) that is less responsive to TMT. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
Reports eyelid conditioning data for 85 male New Zealand white rabbits, employing UCS durations of 50, 100, and 200 msec. Ss with a 50-sec UCS were slower to start conditioning than the 100- or 200-msec groups. The 200-msec group reached a lower terminal performance level than the other 2 groups. Results are related to drive-reduction theory and to possible technical difficulties in the presentation of the cheek-shock UCS. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
Cruikshank Scott J.; Edeline Jean-Marc; Weinberger Norman M. 《Canadian Metallurgical Quarterly》1992,106(3):471
The medial division of the medial geniculate nucleus (MGm) and the posterior intralaminar nucleus (PIN) are necessary for conditioning to an auditory conditioned stimulus/stimuli (CS), receive both auditory and somatosensory input, and project to the amygdala, which is involved in production of fear conditioned responses (CRs). If CS–unconditioned stimulus (UCS) convergence in the MGm-PIN is critical for fear conditioning, then microstimulation of this area should serve as an effective UCS during classical conditioning, in place of standard footshock. Guinea pigs underwent conditioning (40–60 trials) using a tone as the CS and medial geniculate complex microstimulation as the UCS. Conditioning bradycardia developed when the UCS electrodes were in the PIN. However, microstimulation was not an effective UCS for conditioning in other parts of the medial geniculate or for sensitization training in the PIN or elsewhere. Learning curves were similar to those found previously for footshock UCS. Thus, the PIN can be a locus of functional CS–UCS convergence for fear conditioning to acoustic stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
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) 相似文献
8.
Reports 2 experiments in which 80 male and 96 female Blue Spruce rats were presented a serial CS procedure consisting of 2 components: S1 followed by S2 (S1/S2). In both experiments the stimulus similarity of S1 to S2 in terms of tonal frequency was systematically manipulated. Exp I tested the effects of similarity of components in a standard shuttle-box avoidance situation. Exp II employed a conditioned emotional response paradigm measuring the suppression of consummatory licking. Results suggest that the amount of fear elicited by S1 is a direct function of the stimulus similarity of S1 to S2, and support a generalization interpretation of fear transference. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
The strength of the orienting response (OR) to a light and its associability was studied in three experiments. In Experiment 1, three groups of rats received serial conditioning in which the light served as the first element of a serial compound. For Group Diff the light was followed by a conditioned stimulus (CS) of 10-s duration on some trials and by a different CS of 30-s duration on others. For the other groups, the light was also followed by a different stimuli, but these had equivalent durations. This procedure resulted in stronger OR toward the light in Group Diff than in either of the other groups. In Experiments 2 and 3 the OR was stronger to a light that was followed by a 10-s CS on some trials and on a 30-s CS on others than to one that was followed by different CSs that were both randomly either 10 s or 30 s. Following this training, both excitatory and inhibitory conditioning with the light was faster in those groups for which the light elicited a strong rather than a weak OR. These results are most readily explained by the proposal that the strength of the OR toward a CS is determined by the accuracy with which the value of its immediate consequences can be predicted and that this OR can be used as an index of the associability of the CS. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
Westbrook R. Frederick; Iordanova Mihaela; McNally Gavan; Richardson Rick; Harris Justin A. 《Canadian Metallurgical Quarterly》2002,28(1):97
The authors studied the role of context in reinstatement. Freezing was reinstated when the conditioned stimulus (CS) was extinguished in 1 context and rats moved to another context for reexposure to the shock unconditioned stimulus (US) and test. It was also reinstated (rather than renewed) when rats were shocked in the extinction context and moved to another context for test. This reinstatement was CS specific and reduced by nonreinforced exposures to the extinction context. Rats shocked in the context in which a stimulus had been preexposed froze when tested in another context. These findings suggest 2 roles for context in reinstatement: conditioning of the test context (M. E. Bouton, 1993) and mediated conditioning by the extinction context (P. C. Holland, 1990). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
11.
Salafia W. Ronald; Daston Anthony P.; Bartosiak Robert S.; Hurley James; Marino Linda J. 《Canadian Metallurgical Quarterly》1974,86(4):628
Examined the effects of different placements of electrodes used to present a shock UCS on conditioning the rabbit nictitating membrane response (NMR) in 2 experiments with 32 New Zealand and 24 albino rabbits. Ss were conditioned with shock leads attached either circumorbitally, at the ear base, or at the ear tip. In 1 circumorbital shock group, nictitating membranes of both shocked and unshocked eyes were monitored. Circumorbital, ear base, and ear-tip shock yielded best to poorest performances, respectively, and the shocked membrane yielded better performance than the unshocked one. Analysis of UCR and CR latencies and peak amplitude, as well as slow motion films of responses, suggests that poorer performance resulted from the elicitation of other responses, of which the NMR may have been a secondary or indirect component. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
12.
Schreurs Bernard G.; Smith-Bell Carrie A.; Burhans Lauren B. 《Canadian Metallurgical Quarterly》2011,125(4):604
Heart rate conditioning is used as an index of conditioned fear and is important for understanding disorders of anxiety and stress, including post traumatic stress disorder (PTSD). One important feature of PTSD is that patients generalize conditioned fear from danger signals to safety signals especially when the two signals have overlapping features. What has not been determined is whether generalization occurs between unconditioned stimuli with overlapping features. In the current experiment, heart rate conditioning and conditioning-specific reflex modification of rabbit heart rate were examined as a function of two different unconditioned stimulus locations. Heart rate conditioning occurred at identical terminal levels whether electrical stimulation was presented near the eye or on the back. Despite different heart rate response topographies to electrical stimulation at the two locations, conditioning-specific reflex modification was detected near the eye and on the back and appeared to generalize between the locations. Interestingly, only conditioning-specific reflex modification detected on the back persisted for a week after heart rate conditioning. This persistence may be a model for some features of post traumatic stress disorder. Overgeneralization of unconditioned responses to unconditioned stimuli similar to the trauma may also be an important aspect of PTSD modeled here. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
13.
Stetter Kathleen R.; McCann Lee I.; Leafgren Mark A.; Segar Michael T. 《Canadian Metallurgical Quarterly》1995,109(4):384
The relative contributions of social and stimulus factors in development of rat dietary preferences were examined. Investigation of odor-alone effects revealed that weak odors resulted in preference for familiar-odor diets, but only at longer exposure times. Shorter exposure to strong odors also produced differences in diet preference. When odor and conspecific presence were manipulated simultaneously, odors produced no diet preference at low intensities, whereas high-intensity odors did so regardless of conspecific presence. Medium-intensity odor concentrations produced differences only with conspecifics present, indicating social enhancement of stimuli that are ineffective in isolation. These results suggest the separate influence of social and stimulus factors on dietary preferences and explain contradictions in previous studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
14.
In 5 experiments with 164 male Wistar rats, Ss administered morphine (5 mg/kg, sc) during each of several daily sessions in an open field showed an increase in locomotor activity. Since increases were not observed in Ss given morphine in a different environment (home cage) and saline in the open field, it is concluded that they were due to conditioning. Increases in activity were retained over a 7-day rest period; they were also produced when a 2nd opiate (5 μg/kg etorphine) was substituted for morphine, were not seen when 2 mg/kg naloxone (ip) was administered during treatment, and were present in Ss showing tolerance to opiate-produced hypoactivity. Morphine's direct effect on activity is believed to have a biphasic dose–response curve; therefore, the relation of dose to conditioning was also studied. Increases in activity were the only conditioned behaviors observed; they were present only at the higher doses (16, 4, and 1 vs .25, .065, and 0 mg/kg), and they occurred whether or not the dose was associated with unconditioned hypoactivity. Discussion deals with the relation of conditioning and morphine tolerance, the question of whether the UCS of morphine conditioning is a compensatory or a direct effect of morphine, and the similarity of conditioned increases in activity produced by morphine and by other reinforcing stimuli. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
15.
Three experiments used rats as subjects to investigate the generalization of conditioned responding between stimuli as a function of the subjects' exposure to these cues prior to conditioning. Experiment 1 used a between-subjects design, food as the reinforcer, and measured the tendency of subjects to approach the site of food delivery during the stimuli. Generalization of this response was more marked when the training and test stimuli were equated in terms of their novelty (i.e., when both were novel or both were familiar) than when the stimuli differed in this respect (i.e., when one was novel and the other was familiar). Experiments 2a and 2b used within-subjects designs to confirm the reliability of the results of Experiment 1. Implications of these results for current theories of stimulus representation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
16.
Buron Gaelle; Hacquemand Romain; Pourie Gregory; Lucarz Annie; Jacquot Laurence; Brand Gerard 《Canadian Metallurgical Quarterly》2007,121(5):1063
Synthetic 2,4,5-trimethylthiazoline (TMT)--a component of red fox (Vulpes vulpes) feces--is frequently used to induce unconditioned fear in rodents. Surprisingly, direct comparison between TMT and natural fox feces odor is almost nonexistent. In this study, Experiment 1 compared the avoidance in relation to TMT concentration, natural fox feces, and gender of fox and mice. Results show that the avoidance is (a) higher with either pure or 50% TMT as compared to natural fox feces, whereas the difference is slight with 10% TMT, and (b) significantly higher for the female mouse group compared to the male mouse group with TMT as well as natural fox feces. In addition, no clear difference in effect was observed between male and female fox feces. Experiment 2 compared behavioral parameters recorded as an index of fear and anxiety, general activity, and avoidance in elevated plus-maze and open-field chamber between 10% TMT and natural fox feces in relation to the estrus cycle of the mice. Results show no cycle period effect--except for the avoidance parameter "distance to odorant"--and no different effects between 10% TMT and natural fox feces except for freezing. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
17.
Heat was found to be effective as a conditional stimulus in the aversion failure procedure (S. Revusky et al; see record 1980-27581-001) and was also found to be effective as an unconditional stimulus using a taste aversion procedure in which rats exposed to high ambient temperature following saccharin consumption showed robust saccharin aversions relative to unpaired and unheated controls. The antisickness and taste aversion conditioning evidence force reexamination of the view that toxic heat effects are referred to the external environment. Together with other recent evidence from this laboratory, these data support the hypothetical antisickness mechanism of aversion failure, which requires that toxic heat serve as an internal stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
18.
Ohyama Tatsuya; Horvitz Jon C.; Drew Michael R.; Gibbon John; Malapani Chara; Balsam Peter D. 《Canadian Metallurgical Quarterly》2000,114(6):1251
Many drugs need to be taken multiple times to achieve a therapeutic effect. Researchers have identified several mechanisms to account for the slow onset of drug action, including drug accumulation and structural changes induced by drugs. This article provides an example of a new mechanism to account for this change in drug action. Stimuli that accompany drug administration may come to evoke conditioned responses (CRs), and these CRs may be the basis for changes in drug efficacy. Specifically, this research shows that a dopamine antagonist, pimozide, changes response rates through the direct action of the drug but changes time perception through the CRs elicited by drug administration. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
19.
Rusiniak Kenneth W.; Palmerino Claire C.; Garcia John 《Canadian Metallurgical Quarterly》1982,96(5):775
Three experiments with 94 male Sprague-Dawley rats tested the contribution of nonassociative neophobia and sensitization to the potentiation of odor by taste. In Exp I, neophobia for almond odor (O), saccharin taste (T), and odor-taste compound (OT) cues was tested before and after noncontingent LiCl poisoning and compared with conditioned aversions produced by OT–LiCl temporal pairing. The OT compound potentiated unconditioned neophobia, but there was no evidence of poison-enhanced neophobia, disinhibition of neophobia, or sensitization by noncontingent LiCl; temporal pairing produced aversions for the compound and its elements. In Exp II, generalization to a novel odor was tested after O–LiCl or compound OT–LiCl pairing. The potentiated odor aversion did not generalize to the novel odor; it was specific to the odor paired with taste and LiCl. In Exp III, potentiation of the odor component by a discriminant or nondiscriminant taste component was tested. Potentiation was evident only when a novel discriminant taste was in compound with odor prior to LiCl poisoning. Results from all experiments support an associative "indexing" hypothesis of the potentiation effect in rats. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
20.
Barnes Steven J.; Pinel John P. J.; Francis Lee H.; Wig Gagan S. 《Canadian Metallurgical Quarterly》2001,115(5):1065
The authors showed that conditional effects of the stimulation environment modulate both the ictal and interictal behaviors of rats subjected to amygdala kindling. Rats received 53 stimulations to the left basolateral amygdala in 1 conditional stimulus (CS) context (CS+) and 53 sham stimulations (the stimulation lead was attached but no current was delivered) in another context (CS-), quasirandomly over 54 days. Three kinds of conditional effects were observed, First, after several stimulations, less ambulatory activity, more freezing, and less rearing reliably occurred in the CS + context than in the CS context. Second, after 45 stimulations, all of the rats chose the CS - context over the CS + context in a conditioned place preference test. Third, when the rats were finally stimulated in the CS- context, their motor seizures were less severe: Latencies were longer, motor seizures were shorter, convulsive patterns were of a lower class, and there were fewer falls. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献