Processing Multiple Unrelated Meanings versus Multiple Related Senses Ekaterini Klepousniotou McGill University

The so-called ambiguity advantage effect  Previous studies of lexical ambiguity reported faster reaction times for lexically ambiguous words than for unambiguous words in visual lexical decision tasks  “ambiguity advantage” effect  However, it is not clear what type of ambiguity is producing this effect

Theoretical distinctions of lexical ambiguity  Homonymy: a lexical item “accidentally” carries two (or more) distinct and unrelated meanings  “pen 1”  “a writing device” and “pen 2”  “an enclosure”  Polysemy: a single lexical item has several different but related senses  “mouth”  “organ of body” and “entrance of cave”

 Two types of polysemy:  Metaphorical: relation of analogy holds between the senses; it is irregular  “eye”  “organ of the body” and “hole in a needle”  Metonymic: relation of connectedness holds between the senses; it is regular  “rabbit”  “the animal” and “the meat of that animal”

 The distinction between words with multiple meanings and words with multiple senses has been the subject of limited investigation, e.g. Rodd et al. (2002)  However, classification based on standard dictionaries  In the present study:  homonymous words  chosen from standardized lists  metonymous and metaphorical words  chosen to exhibit specific relations between their two senses

Research Questions  Are ambiguous words with multiple unrelated meanings (i.e., homonymous words) processed differently from ambiguous words with multiple related senses (i.e., metonymic and metaphorical polysemous words)?  Is the “ambiguity advantage” actually a “sense- relatedness advantage”?

Predictions  Based on the “meaning-relatedness” hypothesis, it was predicted that:  ambiguous words with multiple related senses (i.e., polysemous words) < control words (i.e., CW)  metonymous words < CW  metaphorical words <? CW  ambiguous words with multiple unrelated meanings (i.e., homonymous words) = CW

Method  Participants. Eighteen native speakers of English Average age: 25 (range 20-35) Average education: 17 (range 15-25)  Task. Single-word visual lexical decision

 Procedure. For example: Fixation point ISIVisual Target Response Key ##### (150 ms)100 mspenyes ##### (150 ms)100 mshotelyes ##### (150 ms)100 msviodinno

 Materials.  Experimental target words consisted of three sets of ambiguous words:  homonymous words: “pen”  “a writing device” and “an enclosure”  polysemous words with metaphorical extensions: “eye”  “organ of the body” and “hole in a needle”  polysemous words with count/mass metonymic extensions “rabbit”  “the animal” and “the meat of that animal”

 Materials.  All ambiguous words had the same orthographic and phonological forms but different meanings  Equal number of unambiguous control words, matched for frequency of occurrence and length, to experimental ambiguous words  Equal number of non-word and real word targets

Mean RTs (in msec) for each condition CW: unambiguous frequency control word W: ambiguous word

Conclusion  Results support our hypothesis that there is a processing advantage for ambiguous words with multiple related senses, but not for ambiguous words with multiple unrelated meanings  Processing advantage confined to metonymically polysemous words, which have senses that are closely related in meaning  Metaphorical words, however, did not show such a processing advantage, due to the fact that their senses are more lexicalized

 Thus:  Results suggest that contrary to common view in literature, there is no processing advantage for words with multiple unrelated meanings (i.e., homonymous words)  The so-called “ambiguity advantage” effect has to be re-defined to reflect the “sense-ambiguity” effect

Implications for future research  The nature of mental representations  Possibly different mental representations depending on the type of ambiguity  Homonymy  distinct mental representations for each meaning  Polysemy  a single mental representation

 Lexical ambiguity studies  Important implications for neurolinguistic studies involving lexical ambiguity:  Patients with right hemisphere lesions are shown to have problems with ambiguous words  Better description of their linguistic abilities if we are able to distinguish between different types of lexical ambiguity

Acknowledgments Dr. Shari Baum Dr. Brendan Gillon Dr. Eva Kehayia McGill Major Scholarship McGill Medicine Internal Studentship