Introduction

•Complex words may be either (a) stored as full forms in the mental lexicon, or (b) undergo decomposition into their constituent morphemes during processing

•The latter account of morphological processing is supported by the finding that the presentation of a morphologically related prime facilitates target processing, and the effects of morphological priming are greater than those found for purely semantically related or purely orthographically related primes.

•Morphological priming effects can be accommodated by two classes of models. The supra-lexical model (Giraudo and Grainger 2000; 2001), holds that morphologically complex words are represented as whole units at the level of form, but that morphological relatives are linked to common morphological representations at a higher, more abstract level of linguistic structure.

•In contrast to the supra-lexical account, Taft and Forster (Taft, 1994; Taft & Forster, 1975) have proposed a sub-lexical model in which morphemes are activated via their constituent graphemes, and these activated morphemes in turn activate the word units above them

•The supra-lexical and sub-lexical hypotheses differ with respect to their predications about the role of semantic relatedness in morphological priming.

Morpho-Orthographic and Morpho-Semantic Influences in Early Visual Word Recognition: An Morpho-Orthographic and Morpho-Semantic Influences in Early Visual Word Recognition: An ERP Investigation Using Masked PrimingERP Investigation Using Masked PrimingJoanna Morris1, Jonathan Grainger2 & Phillip J. Holcomb3

Hampshire College, Amherst, MA1; CNRS & University of Provence, Marseille, France2;Tufts University, Medford, MA3

Discussion

•In both experiments, we found a significant reduction in the N250 for related items across all three conditions.

•In Experiment 2 we also found a reduction of the N400 component.

•For both the N250 and the N400, the effects for the Opaque and Orthographic conditions were not as robust as for the Transparent condition.

•These data suggest that masked morphological priming is at least partly subtended by an early pre-lexical decomposition mechanism that works best for transparent primes.

•Because both the N250 and the N400 showed graded effects across with three conditions, our data suggest that the pre-lexical decomposition mechanism is based on properties that change in a monotonic fashion among the three conditions. One such property is the strength of the transition probabilities between bigrams (See Figure 4).

•The results of the present study suggest that the N250 component is sensitive to statistical sublexical regularities, such as transitional probabilities that govern a chunking process that divides the stimulus into salient sub-units. The fact that these sub-units often correspond to morphemes would simply be because morphemes, by definition, represent highly recurring orthographic and phonological patterns.

Figure 2: ERPs to targets preceded by primes with a (a) semantically transparent (b) semantically opaque and (c) orthographic relationship. Prime duration is 50 ms

This research was supported by HD25889 and HD043251

•In the supra-lexical model, morphological representations are contacted after whole-word representations, and thus the meaning of the whole-word should influence the extraction of the morphological constituents that comprise the word. Thus only semantically transparent morphological primes should result in facilitation of target processing.

•Recent studies that have obtained significant priming with semantically opaque primes have been problematic for the supra-lexical hypothesis (Longtin, Segui, & Halle, 2003; Rastle, Davis, & New, 2004)

•The goal of the current set of studies was to investigate the role of semantic information in the segmentation of morphologically complex words, by examining event-related responses to targets primed by semantically transparent, semantically opaque and orthographically, but not morphologically, related primes using the masked priming paradigm.

Method•48 adults (9 men and 15 women in Experiment 1 and 13 men and 11 women in Experiment 2). Age Range: 18-26 yrs (Mean = 20.8 yrs.)

•The stimuli were 324 prime-target pairs that had (a) were morphologically related and had a semantically and orthographically transparent relationship (hunter-hunt), (b) were not morphologically related and had a semantically opaque relationship (corner-corn) (c) were orthographically but not semantically or morphologically related (scandal-scan).

•The primes were presented for 50 milliseconds in Experiment 1 and for 100 milliseconds in Experiment 2 in order to manipulate the degree of prime processing.

•Subjects were instructed to monitor the list of words for words that referred to articles of clothing and press a button on a game controller when such a word appeared.

ReferencesGiraudo, H., & Grainger, J. (2000). Effects of prime word frequency and cumulative root

frequency in masked morphological priming. Language & Cognitive Processes, 15(4-5), 421-444.

Giraudo, H., & Grainger, J. (2001). Priming complex words: Evidence for supralexical representation of morphology. Psychonomic Bulletin & Review, 8(1), 127-131.

Longtin, C.-M., Segui, J., & Halle, P. A. (2003). Morphological priming without morphological relationship. Language & Cognitive Processes, 18(3), 313-334.

Rastle, K., Davis, M. H., & New, B. (2004). The broth in my brother's brothel: Morpho-orthographic segmentation in visual word recognition. Psychonomic Bulletin & Review, 11(6), 1090-1098.

Taft, M. (1994). Interactive-activation as a framework for understanding morphological processing. Language & Cognitive Processes, 9(3), 271-294.

Taft, M., & Forster, K. I. (1975). Lexical storage and retrieval of prefixed words. Journal of Verbal Learning & Verbal Behavior, 14(6), 638-647.

Figure 3: ERPs to targets preceded by primes with a (a) semantically transparent (b) semantically opaque and (c) orthographic relationship. Prime duration is 100 ms

Figure 1

Figure 4