The retarding effect of the TRC response-elimination procedure upon the subsequent reacquisition of autoshaping: Comparison of between- and within-subjects assessment procedures and the evaluation of the role of background contextual stimuli

In Experiment 1, two groups of pigeons were autoshaped to a green keylight CS and then administered either CS only or truly random control (TRC) response-elimination procedures with the green keylight CS. The groups ceased responding at comparable rates. In a subsequent reacquisition test with a vertical-line key stimulus, the group administered CS only during response elimination reacquired the keypecking CR more rapidly. The two groups were then administered the alternative response-elimination treatment with the vertical-line CS. Again, the groups ceased responding at comparable rates. In a subsequent reacquisition test with a red keylight CS, the group administered CS only during the immediately preceding response-elimination phase reacquired the keypecking CR more rapidly. In Experiment 2, following initial acquisition, the CS-only and TRC response-elimination treatments were administered under the context-change and no-context change conditions. The TRC/context-change and CS-only/context-change groups ceased responding more rapidly than either the TRC/ no-context-change or CS-only/no-context-change groups. In subsequent reacquisition to a novel CS, the CS-only/no-context-change group reacquired the fastest, the TRC/no-context-change group reacquired the slowest, and the CS-only/context-change and TRC/context-change groups reacquired at similar intermediate rates. Implications of these results for the context-blocking hypothesis are discussed.