Conditioned Avoidance Task Research Articles

Effects of chronic d-amphetamine sulfate administration during development in rats

The present investigation was concerned with the effects of long-term administration of d-amphetamine in the daily drinking water of rats on weight and three behavioral tasks. No tolerance to the drug was found for weight measures, nor in the behavioral measures of lever pressing for illumination change or gross activity. Drug animals were significantly lighter than non-drug animals, pressed more for illumination change, and were more active. No difference was found between performance of drug and non-drug animals in an avoidance conditioning task. It may be that tolerance to the drug does not appear when measured by situations not employing strong motivational conditions (e.g. pressing for illumination change and activity), but where such conditions are employed (e.g. shock), tolerance as reflected in the lack of difference between drug and non-drug groups does appear.

Discharge of Purkinje and cerebellar nuclear neurons during rapidly alternating arm movements in the monkey.

Discharge of Purkinje and cerebellar nuclear neurons during rapidly alternating arm movements in the monkey.

Effects of p-chlorophenylalanine on conditioned avoidance learning

A single injection of p-chlorophenylalanine enhanced the performance of two strains of rats in a conditioned avoidance task. The enhancement was especially evident at low UCS intensities for one strain and at high UCS intensities for the other strain. Chronic p-chlorophenylalanine treatment retarded the performance of rats and mice in conditioned avoidance tasks.

A note on the action of methyl pentynol carbamate in strains of rats bred for differential conditioning ability.

Two strains of male rats, selectively outbred for differences in ability to learn a conditioned avoidance task, were compared for degrees of post-training stress in terms of activity (rearing) suppression. Further, the effect of the tranquilizing drug methylpentynol carbamate upon this suppression of activity in the strains was examined. It was found that although activity was suppressed by experience in the learning situation, there was no difference between the strains in respect of the amount of this suppression. The drug in the dosage employed appeared to have no effect either upon activity or its suppression.

Response contingent shock and avoidance conditioning

Hooded rats were trained on an avoidance conditioning task with varying amounts of response contingent shock (RCS) for the first 20 trials. RCS was either manipulated (withheld or added) or not manipulated when S began to respond during the CS-UCS interval. Ss were tested in 30 additional trials. RCS increased freezing and individual differences, and decreased mean avoidances. It is suggested that withholding shock has a combined effect of reducing freezing and of behavior shaping.

Transitory behavioral effects of interpeduncular nucleus damage

Previous research on rats has shown that the interpeduncular nucleus is implicated in retention of various learned habits. The present study tested whether the deficit in retention resulting from lesions in it is subject to diminution by lengthening the postoperative recovery period from 1 week to 3 weeks. Prolongation of the recovery period abolishes the deleterious effects of interpeduncular nucleus damage on retention of both an avoidance conditioning task and a visual discrimination habit. In contrast, experiments on other brain-stem areas (posterior thalamus and lateral hypothalamic area) found to be critical for visual retention showed that the consequent deficits are largely unaffected by variations in the length of the recovery period.