Inflectional and derivational morphology in the mental lexicon: Symmetries and asymmetries in repetition priming

Using a repetition priming paradigm, the interrelations between morphologically related words in the mental lexicon were examined in two experiments. In contrast to most previous studies, in which morphologically complex words occur as primes and stems as targets, derivationally and inflectionally complex forms were fully crossed in prime-target pairs. Experiment 1 showed asymmetries in the pattern of priming effects between different inflectional forms of German adjectives. Such asymmetries are problematic for any theory that assumes that all members of an inflectional paradigm share one entry in the mental lexicon. Experiment 2 contrasted derivational and inflectional variants of the same stems used in Experiment 1. Once again, there were same clear asymmetries in the pattern of priming effects. The implications of these results for models of lexical organization of inflectional and derivational morphology are discussed.     

Processing of English inflectional morphology

The present paper explores the representation of inflectional morphology in the English lexicon. There has been a long-standing debate about how these inflectional relationships might be involved during on-line processing. Inflected forms may be derived from an uninflected base form by rule application; by contrast, both regular and irregular inflection may be treated in the same way, with morphological patterns emerging from mappings between base and inflected forms. The present series of experiments investigated these issues using a lexical decision task. The first experiment showed that response latencies to nouns were significantly shorter than those to verbs. A possible explanation for these results can be found in differences in inflectional structure between English nouns and verbs. Namely, the relative frequency of uninflected compared with inflected forms is greater for nouns than for verbs. Two additional experiments compared noun stimuli with different inflectional structures. In all cases, differences in response latencies were predicted by the frequency of the surface form, whether uninflected or inflected. The pattern of results lends support for a unitary associative system for processing regular inflection of nouns in English and argues against the view that regular inflected plurals are derived by rule from a single, uninflected lexical entry.     

On the representation of Portuguese gender-inflected words in the mental lexicon

This study aims at verifying whether Portuguese gender-inflected nouns and adjectives are represented as full forms as suggested by Spanish data (Dominguez, Cuetos, & Segui, 1999). A series of lexical decision experiments is reported. Grammatical gender, frequency dominance, and grammatical category are manipulated and cumulative frequency is controlled. The results do not provide support for a full form representation of gender-inflected words. They suggest that grammatical category, or the nature of the inflectional process involved (lexical or syntactic), affects the way words are represented and accessed. Shorter recognition latencies were obtained for nouns drawn from Feminine dominant gender-inflected pairs than from Masculine dominant pairs whereas a tendency in the opposite direction was observed in adjectives. The effect of frequency dominance appears, nevertheless, to be restricted to feminine nouns. The data are compatible with the view that masculine nouns and adjectives are represented as gender-unmarked forms. These results are discussed in relation to current dual-access models of word recognition and to the notion of "interpretability" of lexico-syntactic features, as put forward in the Minimalist Program of Generative Linguistics.     

Derivation by prefixation in Slovenian: two aphasia case studies

The present study is concerned with two Slovenian-speaking patients who were asked to produce, in various tasks, verbs, nouns, and adjectives derived by prefixation with prepositions. Despite differences due to their specific linguistic difficulties, both patients' performance was characterized by the differential processing of prefixes and remaining components of complex words. Prepositions in prefixation were mostly preserved, and less frequently substituted, regardless of the numerous errors produced in the remaining portion of the words. These errors seem clearly determined by the morphological structure of the words and therefore appear to be authentic morphological errors. These findings contribute to the theoretical debate on mental lexical representation, speaking in favor of a morphological decomposition in processing of prefixed complex words at different processing levels.     

Lexical Representation and Processing of Morphologically Complex Words: Evidence from the Reading Performance of an Italian Agrammatic Patient

The study of patients with acquired language disorders has provided crucial evidence for contemporary theories on mental lexical representation. This is particularly true for the representation of morphologically complex words. In this paper we analyzed the performance of a patient (M.B.) affected by agrammatism and dyslexia. M.B. was required to read aloud simple and morphologically complex words. The patient's pattern of errors was interpreted as the result of a predominant use of the lexical routine (phonological dyslexia). Three reading tasks were developed which allowed us to test M.B.'s ability to read morphologically complex words (reading of regular and irregular plurals; reading of high- and low-frequency singular and plural nouns; reading of evaluative suffixes). Errors were determined by frequency effect rather than by type of suffix (i.e., inflectional or derivational). High-frequency morphologically complex items seemed to meet stored representations, thus avoiding the parsing procedures that are required for less frequent items. These results are in keeping with dual route models of lexical representation of morphologically complex words.     

Lexical access to inflected words as measured by lateralized visual lexical decision

In two lateralized visual lexical decision experiments conducted with normal subjects, we studied hemispheric performance in the recognition of case-inflected Finnish nouns. Previous research employing mainly locative cases has indicated that such noun forms undergo morphological decomposition. The present experiments extend this finding to syntactic cases by showing that nouns with partitive or genitive endings take longer to recognize and elicit more errors than otherwise comparable monomorphemic nominative singular nouns. Morpheme-based recognition of all case-inflected forms would be a particularly appropriate solution for mental lexicon in highly inflecting languages like Finnish: it saves storage space and enables fast recognition of inflected forms not encountered before. In real words, morphological structure did not interact with visual field. However, particularly demanding, morphologically decomposable nonwords elicited more errors in the left visual field/right hemisphere than did nondecomposable nonwords. Our results suggest that at least in Finnish, both hemispheres are capable of morpheme-based access, but this mechanism is more accurate in the left than in the right hemisphere. Received: 21 May 1997 / Accepted: 19 January 1998     

Processing differences between nouns,adjectives, and verbs

Summary Processing differences were investigated for nouns, adjectives, and verbs in Serbocroatian, a language that depends strongly on inflection to convey grammatical information. Four lexical decision experiments were run. Two of them inspected processing of inflected forms of nouns, demonstrating analogous processing for both singular and plural forms. Processing of the nominative case was faster for both grammatical numbers. Reaction times for the various case forms were not related to their respective frequencies of occurrence. Adjectival processing, on the other hand, gave no privileged role to the nominative case and the inflected form frequency had a strong influence. Similarly, verbs also showed frequency-based processing. An explanation was proposed, suggesting that the organization of inflectional processing is dependent on the number of inflectional alternatives available to a given word.This research was supported by National Institute of Health (USA) grants HD-08495 to the University of Belgrade and HD-01994 to the Haskins Laboratories.     

Representation of inflected nouns in the internal lexicon

The lexical representation of Serbo-Croatian nouns was investigated in a lexical decision task. Because Serbo-Croatian nouns are declined, a noun may appear in one of several grammatical cases distinguished by the inflectional morpheme affixed to the base form. The grammatical cases occur with different frequencies, although some are visually and phonetically identical. When the frequencies of identical forms are compounded, the ordering of frequencies is not the same for masculine and feminine genders. These two genders are distinguished further by the fact that the base form for masculine nouns is an actual grammatical case, the nominative singular, whereas the base form for feminine nouns is an abstraction in that it cannot stand alone as an independent word. Exploiting these characteristics of the Serbo-Croatian language, we contrasted three views of how a noun is represented: (1) the independent-entries hypothesis, which assumes an independent representation for each grammatical case, reflecting its frequency of occurrence; (2) the derivational hypothesis, which assumes that only the base morpheme is stored, with the individual cases derived from separately stored inflectional morphemes and rules for combination; and (3) the satellite-entries hypothesis, which assumes that all cases are individually represented, with the nominative singular functioning as the nucleus and the embodiment of the noun’s frequency and around which the other cases cluster uniformly. The evidence strongly favors the satellite-entries hypothesis.     

Rule-based versus associative processes in derivational morphology.

The present article examines whether derivational morphology shows evidence of an associative memory structure. A distributional analysis of stems of attested derivational forms revealed evidence of clustering around phonological properties (gangs) for all nonneutral affixes but only a few neutral affixes. Subjects' acceptability ratings for novel complex words revealed sensitivity to the gang structure associated with the relevant derivational affixes. Results suggest that, like inflectional morphology, derivational morphology shows dissociations between rule-based and associative generalization mechanisms.     

Analogical effects in reading Dutch verb forms

Previous research has shown that the production of morphologically complex words in isolation is affected by the properties of morphologically, phonologically, or semantically similar words stored in the mental lexicon. We report five experiments with Dutch speakers that show that reading an inflectional word form in its linguistic context is also affected by analogical sets of formally similar words. Using the self-paced reading technique, we show in Experiments 1-3 that an incorrectly spelled suffix delays readers less if the incorrect spelling is in line with the spelling of verbal suffixes in other inflectional forms of the same verb. In Experiments 4 and 5, our use of the self-paced reading technique shows that formally similar words with different stems affect the reading of incorrect suffixal allomorphs on a given stem. These intra- and interparadigmatic effects in reading may be due to online processes or to the storage of incorrect forms resulting from analogical effects in production.     

Effects of morphological complexity on phonological output deficits in fluent and nonfluent aphasia

This study examined the effects of morphological complexity on aphasic speakers with lexical-phonological output deficits. Subjects were two fluent and two nonfluent aphasic speakers who repeated morphologically simple words at the same level of accuracy and whose errors were virtually all phonological in nature. They were asked to repeat a variety of morphologically complex (i.e., affixed) words. Results were interpreted within our two-stage model of lexical-phonological production (Kohn & Smith, 1994, 1995), which we expand to include a distinction between derivational and inflectional morphology. When comparing overall performance levels between morphologically simple and complex words, only three subjects exhibited more difficulty repeating the morphologically complex targets. Nevertheless, when comparing repetition accuracy between different types of morphologically complex words (e.g., derived vs. inflected), all four subjects displayed similar patterns. These findings suggested that while morphological complexity has different effects on the two stages within the lexical-phonological output system, the relative effects of different morphological structures are constant. At the level of error analysis, patterns of affix errors distinguished the nonfluent from the fluent subjects in ways that are reminiscent of the affix errors associated with agrammatic and paragrammatic speech. This finding raised questions concerning the relationship between morphosyntactic and morphophonological deficits.     

On the Representation of Inflections and Derivations: Data from Spanish

The four experiments reported in this paper were designed to determine to what extent words are lexically represented in terms of their morphological structure. The experiments are carried out in Spanish, a language with rich morphological resources, using a priming paradigm and a lexical decision task. In particular, they examined the pattern of priming effects in regular inflected words with gender and in derived words, in comparison to those produced by orthographically and semantically related words, by manipulating form similarity and semantic transparency. The results showed, on the one hand, that regular inflected words produced reliable facilitatory effects which are not driven just by form relatedness (Experiments 1 and 2). On the other hand, they showed that both transparent and nontransparent derived forms produced facilitatory effects distinct from purely orthographic and semantic effects (Experiments 3 and 4.). In general, these findings suggest that morphological information is represented in the mental lexicon and may play a central role in the individuation and retrieval of lexical entries.     

Stem Complexity and Inflectional Encoding in Language Production

Three experiments are reported that examined whether stem complexity plays a role in inflecting polymorphemic words in language production. Experiment 1 showed that preparation effects for words with polymorphemic stems are larger when they are produced among words with constant inflectional structures compared to words with variable inflectional structures and simple stems. This replicates earlier findings for words with monomorphemic stems (Janssen et al., 2002). Experiments 2 and 3 showed that when inflectional structure is held constant, the preparation effects are equally large with simple and compound stems, and with compound and complex adjectival stems. These results indicate that inflectional encoding is blind to the complexity of the stem, which suggests that specific inflectional rather than generic morphological frames guide the generation of inflected forms in speaking words.     

Putting the bits together: an information theoretical perspective on morphological processing

In this study we introduce an information-theoretical formulation of the emergence of type- and token-based effects in morphological processing. We describe a probabilistic measure of the informational complexity of a word, its information residual, which encompasses the combined influences of the amount of information contained by the target word and the amount of information carried by its nested morphological paradigms. By means of re-analyses of previously published data on Dutch words we show that the information residual outperforms the combination of traditional token- and type-based counts in predicting response latencies in visual lexical decision, and at the same time provides a parsimonious account of inflectional, derivational, and compounding processes.     

Knowing what a novel word is not: Two-year-olds 'listen through' ambiguous adjectives in fluent speech

Three studies investigated how 24-month-olds and adults resolve temporary ambiguity in fluent speech when encountering prenominal adjectives potentially interpretable as nouns. Children were tested in a looking-while-listening procedure to monitor the time course of speech processing. In Experiment 1, the familiar and unfamiliar adjectives preceding familiar target nouns were accented or deaccented. Target word recognition was disrupted only when lexically ambiguous adjectives were accented like nouns. Experiment 2 measured the extent of interference experienced by children when interpreting prenominal words as nouns. In Experiment 3, adults used prosodic cues to identify the form class of adjective/noun homophones in string-identical sentences before the ambiguous words were fully spoken. Results show that children and adults use prosody in conjunction with lexical and distributional cues to ‘listen through’ prenominal adjectives, avoiding costly misinterpretation.     

Lexical status of inflectional and derivational suffixes: Evidence from Finnish

The present study tested whether Finnish inflectional or derivational suffixes have lexical access units separate from word roots. In three lexical decision experiments, pseudowords carrying a case-inflection required significantly longer rejection times than nonaffixed pseudowords. This suggests that case-inflections have separate lexical access units. Similar effects were obtained for productive derivational suffixes, too. A specific lexical architecture, being able to account for both the present pseudoword results as well as earlier ones obtained with real Finnish nouns, is proposed.     

Semantic networks of English.

Principles of lexical semantics developed in the course of building an on-line lexical database are discussed. The approach is relational rather than componential. The fundamental semantic relation is synonymy, which is required in order to define the lexicalized concepts that words can be used to express. Other semantic relations between these concepts are then described. No single set of semantic relations or organizational structure is adequate for the entire lexicon: nouns, adjectives, and verbs each have their own semantic relations and their own organization determined by the role they must play in the construction of linguistic messages.     

Disentangling the effects of cognitive development and linguistic expertise: a longitudinal study of the acquisition of English in internationally-adopted children

Early language development is characterized by predictable changes in the words children produce and the complexity of their utterances. In infants, these changes could reflect increasing linguistic expertise or cognitive maturation and development. To disentangle these factors, we compared the acquisition of English in internationally-adopted preschoolers and internationally-adopted infants. Parental reports and speech samples were collected for 1 year. Both groups showed the qualitative shifts that characterize first-language acquisition. Initially, they produced single-word utterances consisting mostly of nouns and social words. The appearance of verbs, adjectives and multiword utterances was predicted by vocabulary size in both groups. Preschoolers did learn some words at an earlier stage than infants, specifically words referring to the past or future and adjectives describing behavior and internal states. These findings suggest that cognitive development plays little role in the shift from referential terms to predicates but may constrain children's ability to learn some abstract words.     

Immediate effects of form-class constraints on spoken word recognition

In many domains of cognitive processing there is strong support for bottom-up priority and delayed top-down (contextual) integration. We ask whether this applies to supra-lexical context that could potentially constrain lexical access. Previous findings of early context integration in word recognition have typically used constraints that can be linked to pair-wise conceptual relations between words. Using an artificial lexicon, we found immediate integration of syntactic expectations based on pragmatic constraints linked to syntactic categories rather than words: phonologically similar "nouns" and "adjectives" did not compete when a combination of syntactic and visual information strongly predicted form class. These results suggest that predictive context is integrated continuously, and that previous findings supporting delayed context integration stem from weak contexts rather than delayed integration.     

Errors of Omission in English-Speaking Children's Production of Plurals and the Past Tense: The Effects of Frequency, Phonology, and Competition

How do English‐speaking children inflect nouns for plurality and verbs for the past tense? We assess theoretical answers to this question by considering errors of omission, which occur when children produce a stem in place of its inflected counterpart (e.g., saying “dress” to refer to 5 dresses). A total of 307 children (aged 3;11–9;9) participated in 3 inflection studies. In Study 1, we show that errors of omission occur until the age of 7 and are more likely with both sibilant regular nouns (e.g., dress) and irregular nouns (e.g., man) than regular nouns (e.g., dog). Sibilant nouns are more likely to be inflected if they are high frequency. In Studies 2 and 3, we show that similar effects apply to the inflection of verbs and that there is an advantage for “regular‐like” irregulars whose inflected form, but not stem form, ends in d/t. The results imply that (a) stems and inflected forms compete for production and (b) children generalize both product‐oriented and source‐oriented schemas when learning about inflectional morphology.