McSweeney, F. K., Swindell, S., & Weatherly, J. N. (1996). Within-session changes in responding during autoshaping and automaintenance procedures. Journal of the Experimental Analysis of Behavior, 66, 51-61.

Four pigeons were exposed to autoshaping procedures in which an 8-second light on a response key was followed by food. Pecks on the key had no scheduled consequences. Subjects were also exposed to negative automaintenance procedures in which a peck on the illuminated key canceled the following food. The intertrial interval varied from an average of 7 seconds to an average of 232 seconds in different conditions. Rate of responding usually changed within sessions during autoshaping. Responding also changed within sessions for the 1 subject that responded during negative automaintenance. The within-session patterns of responding were flatter, peaked later, and were more symmetrical around the middle of the sessions at lower rates of food presentation, regardless of whether subjects responded on autoshaping, negative automaintenance, or previously reported variable-interval schedules. These results imply that similar variables produce within-session changes in responding during both classical (Pavlovian) and operant conditioning procedures.

Key words: within-session changes in responding, autoshaping, classical conditioning, operant conditioning, variable-interval schedule, key peck, pigeons