ETUDE DE L'ACTIVITE DES SUBSTANCES PSYCHOTROPES SUR LE COMPORTEMENT DE PUNITION DU PORC

Pigs were conditioned to respond for food on a variable interval schedule. Two types of conditioned stimulus could be presented while the pig was working: one (the CS-) signalled the change from the VI schedule to a continuous reinforcement schedule; during the other (the CS +), each response was rewarded with food and punished at the same time with an electric shock. Conflict was evidenced by the suppression of operant responding during and after the CS+. Anxiolytic sedatives and neuroleptic drugs were administered in order to establish whether they would attenuate the response suppression. Diazepam consistently increased the number of punished responses with little or no effect on the behaviour in the non punishment component; phenobarbital and meprobamate were less effective than diazepam. Neuroleptic drugs decreased the response rate but azaperone and propericiazine increased the number of punished responses. The effects of neuroleptics are discussed in terms of interference with stimulus control and attention. The pig punishment procedure appears to be a sensitive technique to measure the tranquilizing activity of psychotropic drugs.