Freezing as an avoidance response: Another look at the operant-respondent distinction

Groups of rats were trained with shock either contingent on freezing (punishment procedure) or contingent on not freezing (avoidance procedure). Although the different contingencies produced different levels of freezing behavior, these levels were attained immediately rather than over a number of trials. This result, together with the results of control rats, suggest that while freezing can be controlled by both punishment and avoidance procedures, in both cases the effects on freezing are due to elicitation rather than learning.