A stringent test of visuospatial position uncertainty accounts of letter position coding.

The encoding of letter position appears to be relatively flexible. Transposed-letter pseudowords (e.g. CHOLOCATE) are more often misidentified as their base words (CHOCOLATE) compared to replacement-letter pseudowords (CHOTONATE) – transposed-letter effect. One plausible explanation for this effect is that it arises from visuospatial position uncertainty in letter position encoding. To test this account, we conducted two lexical decision experiments. Pseudowords were presented syllable-by-syllable in vertical and zigzag formats, making the position of the critical transposed or replaced letters more noticeable. In Experiment 1, we found a transposed-letter effect in both formats, which was sizeable in the error rates. Experiment 2 introduced a delayed 900-ms response cue to assess whether the transposed-letter effect fully vanishes in the absence of immediate time pressure. Results again showed a transposed-letter effect. Thus, while visuospatial uncertainty contributes to letter position flexibility during word recognition, an additional non-visual component is necessary to fully explain this phenomenon. [ABSTRACT FROM AUTHOR]