Blocking observed in human eyelid conditioning.
Four eyelid conditioning experiments designed to be comparable to rabbit nictitating membrane (NMR) studies examined the blocking phenomenon in humans. All experiments utilized a within-subjects design, with Stage 1 of discrimination, Stage 2 of compound training, and a final test stage comparing responding to the blocked and non-blocked CSs. In two of the experiments (1 and 4) the comparison was made within subjects over all extinction trials. In Experiment 3 the test phase consisted of further reinforced training of the blocked and non-blocked CSs. These three experiments produced evidence of blocking when all extinction trials were entered into the analysis. Experiment 2, which involved a between-subjects comparison, failed to demonstrate the blocking effect. Wide variability both between and within subjects obscured the experimental effects. Post-experimental questionnaires designed to assess awareness of stimulus relations failed to identify a subjective blocking effect and showed no relationship to conditioned eyelid responding.
Martin
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I
Psychology Department, Institute of Psychiatry, London, U.K.
Levey
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D000293:Adolescent; D000328:Adult; D001245:Association Learning; D001288:Attention; D003214:Conditioning, Classical; D003215:Conditioning, Eyelid; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall