Nonword Letter Strings Research Articles

The Effect of Orthographic Structure and Lexical Meaning on “Same-different” Judgments

Pairs of high frequency English words, orthographically acceptable pseudo-words, and non-word letter strings were presented in a “same”-“different” task. The mean reaction times for “same” judgments were ordered; real words were faster than pseudo-words, and pseudo-words were faster than non-words. The RTs for the “different”, judgments showed no differences among the three types of words, except in the first two days of practice in a blocked presentation condition when the difference between the real words and non-words was marginally significant. These and other results suggest that “same” judgments are based upon a comparison process which efficiently uses higher order semantic and orthographic information in words, whereas “different” judgments are based upon comparison process which performs a self-terminating search of the graphemic information in words. The results were also discussed with reference to hierarchical models of word perception and reading.

Detection of single letters and letters in words with changing vs unchanging mask characters

With a forced-choice procedure and tachistoscopic displays, accuracy of identification was compared for letters presented alone vs the same letters embedded in words or in nonword letter strings. The advantage for single letters over letters embedded in words or nonwords was found to depend jointly upon characteristics of the pre- and postmasks and change vs no change in mask characters in nontarget locations at the onset of single letter displays.

Letter identification in relation to linguistic context and masking conditions

With a two-choice detection procedure, identifiability of signal letters was determined in backgrounds of words, nonword letter strings, or homogeneous noise characters. Under high performance conditions of exposure duration and pre- and postmasks, there was a substantial advantage in identifiability of letters presented alone over letters embedded in words; under low performance conditions there were generally no differences between the two types of context, but some interactive effects appeared involving particular letters with serial position and type of background. No differences were obtained between word and nonword contexts. The disparities between these findings and those reported by Reicher (1969) and Wheeler (1970) may be related to the more complete elimination under the present procedures of effects of redundancy on response selection.