Naming Sequentially Presented Letters and Words

Subjects were presented with sequences of letters six units long. The sequences were presented serially so that each letter of a sequence fell upon the same part of a viewing screen as every other one. The task was to name the letters or to name the words they formed. The principal variables were the kinds of words, the duration of a blank interval between the third and fourth letters of a sequence, and the duration of the individual letters. Correct responses were found to increase toward 100% as the duration of the letters approached about 1/3 sec. The magnitude of the interval between the third and fourth letters had little effect upon recognition. Contextual factors were found to exert influences that enabled the words to be grouped over relatively long temporal separations. A distinction can be made experimentally between naming letters and naming the word they spell. In addition, it was found that the subject could sometimes name all the letters in a sequence but got their order wrong. This is taken to indicate differences in the mechanisms associated with identifying events and identifying their temporal order.