Verbal discrimination learning theory and differential eyelid conditioning to related words at three interstimulus intervals

Two experiments examined the relevance of frequency theory and feature analysis models of verbal discrimination learning (VDL) for differential eyelid conditioning to related words. The single reinforced and nonreinforced stimuli were: (a) high associates, (b) homonyms, (c) members of the same taxonomic class, (d) unrelated nouns, or (e) unrelated noun and adjective or verb items. Experiment I examined these five types of relatedness at 1000-msec and 1400-msec interstimulus intervals (ISI), while Experiment II tested ISIs of 1000 msec and 600 msec. Conditioned discrimination was generally poorer at the 600-msec ISI, but neither VDL model’s relatedness interference predictions were fully confirmed. Contrary to frequency theory, associates were no more difficult to discriminate than unrelated words. The feature analysis model was partially supported, in that taxonomic but not homonymic relatedness produced some interference at the 600-msec ISI. Possible process differences between verbal recognition learning and differential conditioning which may account for these results were discussed