The imagery effect and phenomenal background frequency in verbal discrimination learning

A series of four experiments was conducted to assess the role of phenomenal background frequency in verbal discrimination learning and its possible involvement in the imagery effect. The initial two experiments produced a reliable imagery effect for mixed and unmixed lists with respect to concreteness of pair members, regardless of phenomenal frequency manipulations, with words high in objective background frequency. No effects were found for phenomenal background frequency. Experiment 3 involved phenomenal frequency ratings for 200 abstract and 200 concrete words. Experiment 4 evaluated the role of phenomenal background frequency for a mixed list using words low in objective frequency. A reliable imagery effect was again found with no effects for phenomenal frequency. An alternative hypothesis involving differential accrual of situational frequency to abstract and concrete items during verbal discrimination learning to explain the imagery effect was also tested by Experiment 4 but was not supported by the data.