There is no clam with coats in the calm coast: Delimiting the transposed-letter priming effect

Abstract

In this article, we explore the transposed-letter priming effect (e.g., jugde–JUDGE vs. jupte–JUDGE), a phenomenon that taps into some key issues on how the brain encodes letter positions and has favoured the creation of new input coding schemes. However, almost all the empirical evidence from transposed-letter priming experiments comes from nonword primes (e.g., jugde–JUDGE). Indeed, previous evidence when using word–word pairs (e.g., causal–CASUAL) is not conclusive. Here, we conducted five masked priming lexical decision experiments that examined the relationship between pairs of real words that differed only in the transposition of two of their letters (e.g., CASUAL vs. CAUSAL). Results showed that, unlike transposed-letter nonwords, transposed-letter words do not seem to affect the identification time of their transposed-letter mates. Thus, prime lexicality is a key factor that modulates the magnitude of transposed-letter priming effects. These results are interpreted under the assumption of the existence of lateral inhibition processes occurring within the lexical level—which cancels out any orthographic facilitation due to the overlapping letters. We examine the implications of these findings for models of visual-word recognition.

Keywords:

• Transposed-letter effect
• Priming
• Lexicality
• Letter position assignment
• Orthographic encoding

Acknowledgments

The research reported in this article has been partially supported by Grants SEJ2004–07680–C02–02/PSIC, SEJ2006–09238/PSIC and PSI2008–04069/PSIC from the Spanish Government, and by Grant BFI05.310 from the Basque Government. The authors express their gratitude to Ken Forster and Carol Whitney for their comments on an earlier draft.

Notes

¹ Two of the words from the nonword-primed set were discarded from the analyses because their error rates were higher than 50%. These words were CAMPA (a variety of “field”) and UNÍVOCO (“univocal”).

² One target word from the present experiment (i.e., arce, “maple tree”) produced error rates higher than 60%. When this word was taken out from the analyses, the p value of the F2 analysis was reduced to .04.

³ We must bear in mind that, in a priming paradigm, an item is explicitly activated, and the effect on target performance is measured. In contrast, in a single-presentation paradigm, the issue concerns whether partial activation of neighbouring words that were never presented influences responses to the target item.

⁴ We compared the scores for transposed-letter pairs (e.g., ce rd o–CE DR O) and double-substitution pairs (e.g., ce ns o–CE DR O) using the Match Calculator software, Version 1.9, programmed by Colin J. Davis. This application is available at Colin Davis' website: http://www.pc.rhul.ac.uk/staff/c.davis/Utilities/MatchCalc/index.htm