Abstract
Two experiments were conducted in order to investigate the retardation of autoshaping following pretraining with intermittent US (reinforcer) presentations, and to examine the "competing response" hypothesis from Staddon's ideas about "adventitious reinforcement". Six homing pigeons were given 4 stages of training: (1) Unsignalled food delivery on a fixed time (FT) schedule of 12, 24 or 36 sec. (2) Autoshaping with a fixed intertrial interval (ITI). (3) Automaintenance on the fixed ITI with contextual cues changed. (4) Automaintenance on a variable ITI. Experiment 1 (stages 1 and 2) was done in a black wooden chamber, and Experiment 2 (stages 3 and 4) was in a green Plexiglas chamber. The average values of the interfood interval (IFI) for each subject were fixed throughout the 4 stages. Ten response classes that occurred during the IFI were recorded. It was found that: (1) Autoshaping and automaintenance of key-approach responses were retarded by prior FT training. (2) When retardation was found, "superstitious" responses, developed during the FT schedule, continued to occur even when food delivery was signalled. Most of the responses were magazine-directed behaviors. (3) Even in the presence of competing responses, the effects of the signal (CS) on behavior were clear (e.g. emergences of key-directed responses, concentrations of terminal responses during signal presentation). (4) A control group of 6 additional pigeons were given only stages 2, 3 and 4. They autoshaped faster and responded at a higher rate than the pretrained pigeons during stages 2 and 3 but not during stage 4. The key-approach responses of the pretraining group increased on the variable ITI, not context-changed, automaintenance. Implications for theories of retardation and "performance" of autoshaping were discussed.
