Some tests of the interactive-activation model for word identification

SummaryThe interactive-activation model postulates (a) that activation at the letter level leads automatically to activation at the word level, (b) that the word-superiority effect reflects reactivation of letters by the word they spell, and (c) that subjects identify words on the basis of information obtained from separate letter-position channels. In the first two experiments, we showed words in upper, lower, or mixed case: the word-superiority effect was reduced when words were presented in mixed-case letters, presumably because extra-letter information is lost with mixed-case presentation; i.e., postulate (c) is wrong. The third experiment showed that when the letters of a word are rotated 180° subjects can identify the letters without producing a word-superiority effect; i.e., one of postulates (a) and (b) is wrong. In Experiments 4 and 5, we trained subjects to name words presented in inverted letters; training was more effective when subjects could exploit bigram information in addition to letter-channel information; i.e., reading inverted text is based on extra-letter-feature information, not on a general skill in rotating letters. Taken together, our data deny three of the interactive-activation model's major postulates. We offer some suggestions for future versions of the model.