PubMed Health⌕ Search

Biomedical subjects

J J Pear

Publications and source records attributed to J J Pear.

23 records · Page 2Linked to original sources
PubMed1972

Lever attacking by rats during free-operant avoidance.

Rats pressed a lever to avoid shock on a free-operant avoidance schedule. Some subjects were also exposed to extinction in which the response-shock contingency was eliminated while the shock-shock contingency remained in effect. A specially constructed lever was used that registered not only presses, but also biting attacks on the lever. Throughout various phases of the study, shocks often elicited lever biting as well as post-shock responding. The results suggested that shock-elicited attacks that are forceful enough to activate the operandum might account for some of the responding that occurs in experiments on free-operant avoidance behavior. In particular, shock-elicited operandum attacking might account for post-shock response bursting during free-operant avoidance and the extreme persistence of responding sometimes noted when shocks are delivered during the extinction of avoidance behavior. To the extent that this is true, these phenomena should not be characterized as operant behavior in interpreting the results of experiments on free operant avoidance.

Journal Article↗
PubMed1971

Shock as punishment in a picture-naming task with retarded children.

Two retarded children were taught to name pictures according to a standardized procedure. In Exp. I, correct responses were positively reinforced on a five to one ratio under one stimulus condition, incorrect responses were followed with a sharp "no", and the subject was ignored for inattentive behavior. Under another stimulus condition, correct responses were reinforced as in the first condition, but incorrect responses and 5-sec periods of inattentive behavior were followed by "no" and an electric shock. Less inattentive behavior was exhibited and more words were learned to a pre-set criterion in the shock condition than in the no-shock condition. In Exp. II, the ratio of inappropriate responses to shock was varied. The amount of inattentive behavior tended to increase in the shock condition, relative to that in the no-shock condition, as this ratio was increased. Two other measures of performance used in the present experiments were the ratio of errors to correct responses and the number of correct responses. Shock tended to produce better performance on these measures also.

Journal Article↗
PubMed1971

Contrast and induction in rats on multiple schedules.

Eight rats were trained on a variable-interval schedule in the presence of a light (Phase I). Responding was then extinguished in the presence of darkness that alternated with the light (Phase II). Reinforcement was then introduced in the presence of darkness (Phase III). Several rats were then returned to the condition of Phase II (Phase IV) and then to that of Phase III (Phase V). The responding of most rats showed clear behavioral contrast in Phase II-i.e., an increase in responding in the presence of the light. When, for three rats, Phase III was introduced early after the occurrence of positive contrast, either positive induction occurred, i.e., an increase in responding in the presence of the light, or there was little change. Negative contrast did not occur. It was further shown that positive contrast dissipates over time, thus replicating a result previously obtained with pigeons and that the positive induction effect seems also to dissipate over time. The introduction of reinforcement in the presence of darkness (Phases III and V) after the dissipation of positive contrast seemed to have little consistent effect.

Journal Article↗
PubMed1968

Summation of response rates to discriminative stimuli associated with qualitatively different reinforcers.

In Experiment I, a four-ply multiple schedule was used to study the effects on rate of responding in rats of food, water, and food and/or water reinforcement under different deprivation conditions. Food and water were associated separately with different stimuli, the combination of which was associated with food and water together, or with food or water randomly. Rates in the presence of the combined stimuli were consistently intermediate to the rates generated by the separate stimuli, a result seemingly incompatible with a "summation" hypothesis. Experiment II was a simplified systematic replication of Experiment I, verifying the major findings.

Animals↗