SCALING THE EPISODIC FAMILIARITIES OF PICTURES AND WORDS

Most current memory theories assume that judgments of past occurrence are based on a unidimensional familiarity signal. In a test of this hypothesis, subjects studied mixed lists of pictures and words that occurred up to three times each. They then were given two tests: a forced-choice frequency discrimination rest including all pairs of conditions (e.g., picture seen twice vs. word never seen) and a numerical frequency judgment rest on individual items. Forced-choice proportions for all pairings (picture-picture, word-word, and picture-word) were well fit by a one-dimensional scaling solution, suggesting a common basis of recognition and frequency judgments for both pictures and words. Both forced-choice and numerical judgment data indicated that familiarities of pictures started lower than those of words but increased more rapidly with repetition. Results are discussed in connection with the distinction between familiarity and recall, and the possible role of rescaling in the mirror effect.