MORPHOLOGICAL REPRESENTATION AND VISUAL SEARCH : LETTER POSITION EFFECTS IN READING AFFIXES

Abstract

Models of morphological representation and processing comprise two main hypotheses: morpheme-based and whole word based. The morpheme-based approach proposes that affixed words are represented in a decomposed morphemic format (affix and stem) while the word based approach posits independent listing of affixed words as whole entries in the lexicon. The present study investigates differential processing of affixes in words using lexical decision to establish affixation effects and the visual search paradigm to investigate letter position effects. Two within-participant variables were examined: morphological complexity (affixed/pseudoaffixed) and affix type (prefix/suffix). Results obtained using both paradigms demonstrated an advantage of suffixed over prefixed items, indicating a serial access procedure. However, contrary to prediction, no difference was observed between prefixed and pseudoprefixed words whilst suffixed words were recognized significantly faster than pseudosuffixed words. More importantly, letter position effects found in the visual search task and trend analyses showed differential processing of affixes and stems at morpheme boundaries. These findings can be accommodated by the Interactive activation model (Taft, 1994). This is consistent with the morpheme-based approach, suggesting that lexical access operates via morphemes rather than whole word.