Morphology and Meaning in the English Mental Lexicon By William Marlsen-Wilson, Lorraine Komisarjevsky Tyler, Rachelle Waksler, and Lianne Older Presented by Robyn Maler

Questions  How are lexical entries represented in the mental lexicon?  Are their representations based on whole phonetic words (full listing hypothesis) or morphemes (morphemic hypothesis)?  Are there differences between lexical representations at different levels?

Background  Lexical entry is distinct from access representation  Morphological category: the basic linguistic characteristics of the affixes (derivational vs. inflectional, prefix vs. suffix)  Semantic transparency: whether the form is synchronically compositional  Phonological transparency: whether the form has the same phonetic shape for both its affixed and unaffixed versions

Experimental Task Design  Cross-modal immediate repetition priming: subject hears a multimorphemic spoken word (prime) and immediately after sees a visual probe (target)  Subject must make a lexical-decision response to this probe  Response facilitation (priming) is measured by response latency relative to a baseline condition (subject’s response to same probe following unrelated prime)

Questions for Experiments 1-3:  Is the lexical entry for derived suffixed words in English morphologically structured?  How does the semantic and phonological transparency of stem and affix morphemes affect the representation of a derived form?

Experiment 1  Purpose: to determine whether there is evidence for a level of morphologically structured lexical representation that abstracts away from shared surface phonetic properties

Table 1: Experiment 1 ConditionMorphological Type ExampleResult 1: [+Morph, +Phon]Derived-stemFriendly/friendPriming observed 2: [+Morph, -Phon]Derived-stemElusive/eludePriming observed 3: [+Morph, -Phon]Derived-stemSerenity/serenePriming observed 4: [-Morph, +Phon]NATinsel/tinNo priming

Results and Discussion  Results are consistent with hypothesis that derived suffixed forms prime their free stems because of lexical entry processes and not just surface phonetic overlap

Experiment 2  Purpose: to determine whether the priming observed in [+Morph] conditions in Experiment 1 are simply due to semantic relationships between morphologically related pairs instead of shared morphemes in a morphologically structured mental lexicon

Table 2: Experiment 2 ConditionMorphological type ExampleResult 1: [-Sem, +Morph] Derived-stemCasualty/casualNo significant priming effect 2: [+Sem, +Morph] Derived-stemPunishment/punishPriming observed 3: [-Sem, +Morph] Derived-derivedSuccessful/successorNo priming 4: [+Sem, +Morph] Derived-derivedConfession/confessorNo priming 5: [+Sem, - Morph, -Phon] (CONTROL) NAIdea/notionPriming observed 6: [-Sem, -Morph, +Phon] (CONTROL) NABulletin/bulletNo priming

Results and Discussion  Priming only occurs when there is a synchronically semantically transparent relationship between derived and stem forms  Semantic links alone can produce priming, but semantic relatedness is not the only factor affecting facilitation!

Experiment 3  Purpose #1: to study effects of morphological type and semantic transparency more rigorously  Purpose #2: to investigate a new prime-target combination (stem- derived)

Table 3: Experiment 3 ConditionMorphological type ExampleResult 1: [-Sem, +Morph] Derived-stemCasualty/casualNo priming 2: [+Sem, +Morph] Derived-stemPunishment/punishStrong priming observed 3: [-Sem, +Morph] Derived-derivedSuccessful/successorNo priming 4: [+Sem, +Morph] Derived-derivedConfession/confessorNo priming 5: [+Sem, +Morph] Stem-derivedFriend/friendlyStrong priming observed

Results and Discussion  confirm results of Experiment 2  fit with prediction of shared- morpheme account of [+Sem, +Morph] priming

Experiment 4  Purpose #1: to investigate semantic transparency for prefixing morphology  Purpose #2: investigate morphological type (whether derived-derived and derived-stem prefixed pairs exhibit priming effects)

Table 4: Experiment 4 ConditionMorphological type ExampleResult 1: [-Sem, +Morph] Derived-stemRestrain/strainNo priming 2: [+Sem, +Morph] Derived-stemInsincere/sincerePriming observed 3: [-Sem, +Morph] Derived-derivedDepress/expressNo priming 4: [+Sem, +Morph] Derived-derivedUnfasten/refastenStrong priming observed

Results and Discussion  Like the suffixed pairs, only [+Sem] prefixed pairs showed priming  Prefixed [+Sem] derived-derived pairs show strong priming effects, consistent with idea that they are not cohort competitors  Prefixed [-Sem, +Morph] forms (e.g. mistake) are represented as monomorphemic items WHEREAS prefixed [+Sem, +Morph] forms (e.g. refasten) are broken down into abstract stems and prefixes at the level of lexical entry

Experiment 5  Purpose: to investigate stem-derived order in prefixed pairs

Table 5: Experiment 5 ConditionMorphological type ExampleResult 1: [-Sem, +Morph] Stem-derivedStrain/restrainNo priming 2: [+Sem, +Morph] Stem-derivedSincere/insincerePriming observed 3: [-Sem, +Morph] Bound stemsSubmit/permitNo priming 4: [-Morph, +Phon] PseudoprefixedDispatch/patchNo priming 5: [-Morph, +Phon] Initial stressMildew/dewNo priming 6: [-Morph, +Phon] Final stressTrombone/boneNo priming

Results and Discussion  Condition 3 results provide more evidence that there is no facilitation when there is no synchronic semantic basis for representing a word form as morphologically complex  Results consistent with a model of lexical representation in which there are inhibitory links between suffixes but not prefixes that share the same stem

Experiment 6  Purpose: to explore relationship between prefixed and suffixed forms

Table 6: Experiment 6 ConditionMorphological type ExampleResult 1: [+Sem, +Morph] Prefix-suffixDistrust/trustfulPriming observed 2: [+Sem, +Morph] Suffix-prefixJudgment/misjudgePriming observed 3: [-Sem, +Morph] Stem-derivedApart/apartmentNo priming

Results and Discussion  Consistent with a cohort-based model in which there are inhibitory links between competing suffixed forms but not prefixed and suffixed forms

In summary…  Semantically transparent suffixed pairs prime each other except in the case of two suffixed forms, which demonstrate a cohort- based inhibitory effect  Semantically transparent prefixed pairs always prime each other  Semantically opaque pairs do not prime each other  Thus, semantically transparent forms are decomposed at the level of lexical entry, while semantically opaque forms are represented monomorphemically

…cont’d  Phonological opacity had no effect on results  Thus, morphemes are phonologically abstract

What does it all mean?  Results suggest that there is a modality- independent and morphologically structured lexical level  The basic unit in terms of which the lexicon is organized, at least for derivational forms in English, is the developmentally-defined morpheme  The findings are (kind of) consistent with a partial decomposition view of the lexicon