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Biomedical subjects

J Francis

Publications and source records attributed to J Francis.

At least 163 records · Page 9Linked to original sources

Shock-induced aggression as a function of prior experience with avoidance, fighting, or unavoidable shock.

Rats were trained in shock-induced aggression, free operant avoidance, or were presented with unavoidable shocks. Fighting in response to shock was subsequently measured by intermatching individual animals that had received the three training procedures. The fighting probabilities of animals with histories of avoidance and dominant animals with histories of fighting were higher than the fighting probabilities of non-dominant fighting rats or rats with a history of unavoidable shocks. Animals with higher fighting probabilities disrupted avoidance baselines more than animals with lower fighting probabilities. Control experiments suggested that fighting decrements produced by administration of prior grid-shock were due to the acquisition of behaviors incompatible with aggression.

Aggression↗

Frequency of attack in shock-elicited aggression as a function of the performance of individual rats.

Fighting rates between paired rats were investigated as a function of the probability of attack by a single animal. Animals from stable high-fighting and low-fighting frequency pairs were intermatched to detect individual high-fighting and low-fighting rats. Pairs of high-fighting animals then received saline or different chlorpromazine dosages during successive sessions. Finally, single high-fighting members of each pair also received the different drug dosages. The chief findings were that: (a) rats showing high fighting rates when matched against each other revealed low fighting rates when matched against one, but not the other member of a low-fighting pair; and (b) high-fighting rats decreased their fighting rates as their own or their opponent's chlorpromazine dosage increased. These results indicated that a low rate of fighting on the part of one rat results in a low fighting rate on the part of its opponent.

Aggression↗