Antipunishment effects of diazepam: interaction with shock and food deprivation levels in pigs.

The effects of 1mg/kg diazepam on punished behaviour of pigs were investigated under various degrees, of food deprivation and/or shock level. Responses emitted during the punishment signal were affected more by the shock level than by the degree of food deprivation while nonpunished response rates were modified by neither factor. Diazepam treatment increased the number of responses emitted during the punishment signal but interacted with the shock intensity: drug effects were attenuated when the shock intensity was severe, in spite of an equivalent control baseline. Diazepam also increased the overall rate of nonpunished responding. The drug treatment had no reliable effect on flinch and escape thresholds measured in separate experiments. The effects of diazepam on punished responding do not appear to be related to eventual changes in food motivation or sensitivity to electric shock.