Facilitation and interference in indirect/implicit memory tests and in the process dissociation paradigm: the letter insertion and the letter deletion tasks.

This paper introduced the letter insertion and letter deletion tasks. In these tasks participants are presented with letter strings and are instructed to insert or delete a letter to create a word. Experiment 1 demonstrated facilitation priming and established these tasks as sensitive indirect measures of memory. Experiments 2 and 3 demonstrated interference priming effects. In Experiment 4 the process dissociation paradigm (Jacoby, 1991) was applied to investigate the contributions of automatic and consciously controlled processes to performance on the letter insertion task. In addition, performance in the exclusion condition demonstrated an interference effect caused by automatic retrieval. Potential applications for the letter insertion and letter deletion tasks are discussed.