O278-7393/93/S3.OO Direct Comparison of Four Implicit Memory Tests

Four verbal implicit memory tests, word identification, word stem completion, word fragment completion, and anagram solution, were directly compared in one experiment and were contrasted with free recall. On all implicit tests, priming was greatest from prior visual presentation of words, less (but significant) from auditory presentation, and least from pictorial presentations. Typefont did not affect priming. In free recall, pictures were recalled better than words. The four implicit tests all largely index perceptual (lexical) operations in recognizing words, or visual word form representations. Implicit memory tests are those in which retention is mea-sured indirectly by having subjects perform some task os-tensibly unrelated to a prior study phase in the experiment (Graf & Schacter, 1985). Retention is indicated when per-formance on studied items exceeds that on similar items not presented in a prior study phase, a phenomenon commonly referred to as priming. For example, subjects might be ex-posed to a word such as polliwog during the study phase and then later be asked to identify the word from a brief display (a word identification test), to respond with the first word they can think of when provided with the first three letters (a word stem completion test), to complete a word puzzle such as p 1 iwo (a word fragment completion test), or to rearrange presented letters such as olpliwgo to form a word (an anagram solution test). Priming refers to better perfor-mance on studied than on nonstudied words in these tasks. These four implicit memory tests will be examined in the present research. When subjects are given these sorts of tests, the instruc-tions given to disguise the implicit nature of the tests do not guarantee that subjects will eschew the conscious use of memory in performing the task. However, one reason for suspecting that implicit tests measure something different from standard explicit memory tests such as recall or rec-ognition is that often the two types can be dissociated. In-Parts of the research reported here were presented at the 199