[Effects of structural and naming factors of letters upon the recognition of tachistoscopic letters (author's transl)].

To determine the nature of effects of a preceding letter stimulus upon the recognition of a following letter stimulus, 20 subjects were sequentially and tachistoscopically presented pairs of letters of pairs of random patterns, which consist of the same number of elements, and asked to judge whether they were "same" or "different" in form. Four variable interstimulus intervals (ISI) between the 1st stimuli and the 2nd stimuli were employed as parameters. Results obtained were as follows: (a) percentages of correct responses for the letters were not significantly different from those for the random patterns, and (b) percentages of correct responses for the "same" matching tasks were significantly higher than those for the "different" matching tasks, but, differences in number of correct responses between the two tasks diminished as ISI increased. These results reveal structural, rather than naming, effects of preceding letters in the information processing of matching single letters.