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 hy pothesis, subjects studied mixed lists of pictures and words that occu rred 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 freque ncy judgment rest on individual items. Forced-choice proportions for a ll pairings (picture-picture, word-word, and picture-word) were well f it 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 familiaritie s of pictures started lower than those of words but increased more rap idly with repetition. Results are discussed in connection with the dis tinction between familiarity and recall, and the possible role of resc aling in the mirror effect.