Buzzer CS Research Articles

Bidirectional avoidance by mice as a function of CS, US, and apparatus variables

Acquisition of two-way avoidance by mice was slower with a light CS than with a buzzer CS, with punishment of intertrial responses than without punishment, and with a short CS-CS interval than with a long CS-CS interval (30 vs. 60 sec). Light-cued avoidance was little affected by shock level (.35–1.5 mA), whereas mice trained with the buzzer CS learned faster at 1.5 mA. Animals required to move away from light or toward light showed comparable rates of acquisition. Other CS, US, and apparatus variables (directionality of cue, maximal shock duration, and presence vs. absence of a central partition in the shuttlebox) interacted in a complex fashion with those already mentioned. This resulted in widely differing performances in what may superficially appear to be different versions of the same task. The differences in mouse and rat responses to some of the variables can contribute to an understanding of the interactions between organismic and test factors and the relative explanatory value of alternative avoidance models.

Some effects of a buzzer CS and a novel buzzer on self-punitive running in rats

Self-punitive behavior was demonstrated in prepunishment speeds during extinction following shock escape training in a straight runway under buzzer-CS and under no-CS conditions. The buzzer enhanced punished running (shock in the last half of the runway) and nonpunished running. The buzzer did not significantly enhance self-punitive behavior, defined as the difference between punishment conditions with faster running for punished rats than for nonpunished rats. Introduction of a novel buzzer at the beginning of extinction enhanced both punished and nonpunished running relative to no-CS conditions but had no effect on selfpunitive behavior. Discontinuance of the buzzer CS at the end of acquisition eliminated selfpunitive behavior during extinction. The results were interpreted as supporting explanations of self-punitive behavior in terms of fear conditioning and conflict resolution.

Some effects of type of auditory CS on self-punitive running in rats

Self-punitive behavior was demonstrated in prepunishment speeds during extinction following shock escape training in a straight runway under buzzer-CS and tone-CS conditions. Relative to the tone, the buzzer enhanced punished running (shock in the last half of the runway) and nonpunished running. These results extend the findings of Myers (1962), who reported better avoidance conditioning with a buzzer than with a tone. Self-punitive behavior, defined as the difference between punishment conditions with faster running under punishment conditions, was not significantly enhanced by the buzzer. These results do not support the suggestion (Delude, 1973) that self-punitive behavior may be uniquely affected by the use of a buzzer CS.

Fear-motivated vicious-circle behavior maintained through secondary punishment

Two experiments attempted to establish vicious-circle behavior through fear motivation combined with secondary punishment. In Experiment 1, rats were trained with two CSs, a tone and a buzzer, paired with shock in different contexts. Secondary punishment based on delay and trace conditioning procedures facilitated running in fear-motivated rats, relative to four control groups. In Experiment 2, rats were given pairings of a tone CS with shock, and a buzzer CS with a drop into a water tank. Fear-motivated rats which received secondary punishment during either 33% or 100% of test trials exhibited self-punitive running relative to a nonpunished (0%) group and a backward-conditioning control group. Results indicate that “all secondary” vicious-circle behavior can be established through Pavlovian conditioning, thus supporting a conditioned fear interpretation.

Two-way self-punitive locomotor behavior

The effect of an explicit buzzer CS upon self-punitive locomotor behavior was investigated in an experiment utilizing a fully automated two-way locomotor device. Two groups of rats received shock-escape training and extinction, with or without the CS. During extinction, half of the animals in each group were shocked in the middle segment of the alley while the other half were given no-shock regular extinction trials. Rats trained and extinguished with the CS completed more extinction trials than those trained and extinguished without a CS, while rats punished during extinction completed more trials than rats given regular extinction trials. In addition, the punishment-produced facilitation of extinction performance was greater for rats trained and extinguished with the CS than for those without the CS.

Avoidance Learning in the Lizard Dipsosaurus Dorsalis

5 desert iguanas ( Dipsosaurus dorsalis) were given avoidance training on a modified Mowrer-Miller one-way shuttle-box using shock as US and a compound light and buzzer CS. All lizards reached avoidance criterion with a mean of 140 trials. Several procedural factors may account for these results which are in marked contrast to previous reports of failure of lizards in avoidance acquisition. A longer CS-US and inter-trial interval was used in conjunction with high substrate temperature between trials and a more natural pseudo-tunnel one-way escape route.

Effects of magnesium pemoline on avoidance behavior in rats

Following oral injections of either 0, 5, or 20 mg/kg of magnesium pemoline mixed with tragacanth in an equal volume solution, 60 Long-Evans hooded rats were given 70 trials in a two-compartment one-way avoidance apparatus. Type of CS (light vs buzzer) and interval between drug injection and conditioning (30 vs 60 min) were varied factorially with drug dosage. Ss receiving either 5 or 20 mg/kg of magnesium pemoline performed significantly better than did controls, independent of the other two variables. These results fail to support the Beach & Kimble (1967) hypothesis that the major effects of magnesium pemoline on avoidance conditioning are due to an increased aversive responsiveness to a buzzer CS, which has typically been employed in studies of the drug, rather than directly affecting the avoidance learning.

Strain differences in response to shock in rats selectively bred for emotional elimination

Rats of the MNR and MR bi-directionally selected strains were given matched-impedance shocks. Shocks were escapable, inescapable, or inescapable and paired with a buzzer CS. Motor responses and skin resistance, which were recorded during each shock, differed between the strains. It was found that the MNR strain, which learns shuttle-box CARs more quickly than the MR strain, nevertheless performed more motor responses incompatible with efficient shuttle-box crossing than the MR. This paradox is discussed and it is concluded that study of behaviour other than motor response to shock is needed to clarify the determinants of avoidance behaviour in these strains.

Facilated responding in a discriminated lever press avoidance situation

Discriminated lever press avoidance training conditions were studied to determine some factors necessary for optimal, consistent responding in rats. Buzzer during training evoked a high level of performance, the first training session with buzzer CS being critical in producing avoidance responses which could carry over to later sessions. Exposure to free operant avoidance sessions facilitated later discriminated avoidance performance. Very few Ss failed to learn at a high level of proficiency under these conditions.

The differential effects of plasma from two groups of clinically similar schizophrenic patients on learning behavior in rats

The effects of plasma from normal subjects and chronic schizophrenic patients were determined on the rate of learning a pole jump response in rats. The animals were trained to a buzzer CS and electroshock US. Mean trials to a 90 per cent avoidance criterion were determined using a 100 trial cut off. Plasma and other control solutions were given intraperitoneally in the morning and the procedure repeated in the afternoon with separate groups of rats. Test trials were initiated five minutes after injection. It was found that all plasma, in contrast to saline, produced an increase in the number of trials to learn the avoidance response. No difference in behavioral effects was noted comparing the plasma of all chronic schizophrenics to normals. However, within the chronic schizophrenic population there are subgroups whose plasma was differentially effective in reducing rate of learning. These results are preliminary and subject to continued experimentation. They are presented here to make others awake of the need to consider the existence of possible biologic subgroupings of schizophrenia in future investigations of the plasma-behavior interaction.

Facilitation of classical conditioning in rabbits by reinforcing brain stimulation

Ss receiving positively or negatively reinforcing brain stimulation coupled to an eye-shock UCS achieved classically conditioned nictitating membrane responses to a buzzer CS faster than Ss receiving neutral or no brain stimulation.

Shuttle avoidance: Rapid acquisition by rats to a pressurized air unconditioned stimulus

Thirty-three adult rats were trained in a shuttlebox using a pressurized air US and a 65 decibel buzzer CS. All rats avoided the air blast, and 29 achieved the learning criterion (five avoidance responses in any six trials). Twenty-six of these required 20 or fewer trials to reach criterion. Learning was non-incremental: Ss shifted abruptly from escape responding to avoidance responding. Procedural advantages of air-blast shuttle-avoidance training are noted and applications suggested.