The morphological family size effect and morphology

Malay Lexicon Project 3: The impact of orthographic-semantic consistency on lexical decision latencies

Theories of word processing propose that readers are sensitive to statistical co-occurrences between spelling and meaning. Orthographic-semantic consistency (OSC) measures provide a continuous estimate of the statistical regularities between spelling and meaning. Here we examined Malay, an Austronesian language that is agglutinative. In Malay, stems are often repeated in other words that share a related meaning (e.g., sunyi/quiet; ke-sunyi-an/silence; makan/eat; makan-an/foods). The first goal was to expand an existing large Malay database by computing OSC estimates for 2,287 monomorphemic words. The second goal was to explore the impact of root family size and OSC on lexical decision latencies for monomorphemic words. Decision latencies were collected for 1,280 Malay words of various morphological structures. Of these, data from 1,000 monomorphemic words were analysed in a series of generalised additive mixed models (GAMMs). Root family size and OSC were significant predictors of decision latencies, particularly for lower frequency words. We found a facilitative effect of root family size and OSC. Furthermore, we observed an interaction between root family size and OSC in that an effect of OSC was only apparent in words with larger root families. This interaction has not yet been explored in English but has the potential to be a new benchmark effect to test distributional models of word processing.

LaDEP: A large database of English pseudo-compounds

The Large Database of English Pseudo-compounds (LaDEP) contains nearly 7500 English words which mimic, but do not truly possess, a compound morphemic structure. These pseudo-compounds can be parsed into two free morpheme constituents (e.g., car-pet), but neither constituent functions as a morpheme within the overall word structure. The items were manually coded as pseudo-compounds, further coded for features related to their morphological structure (e.g., presence of multiple affixes, as in ruler-ship), and summarized using common psycholinguistic variables (e.g., length, frequency). This paper also presents an example analysis comparing the lexical decision response times between compound words, pseudo-compound words, and monomorphemic words. Pseudo-compounds and monomorphemic words did not differ in response time, and both groups had slower response times than compound words. This analysis replicates the facilitatory effect of compound constituents during lexical processing, and demonstrates the need to emphasize the pseudo-constituent structure of pseudo-compounds to parse their effects. Further applications of LaDEP include both psycholinguistic studies investigating the nature of human word processing or production and educational or clinical settings evaluating the impact of linguistic features on language learning and impairments. Overall, the items within LaDEP provide a varied and representative sample of the population of English pseudo-compounds which may be used to facilitate further research related to morphological decomposition, lexical access, meaning construction, orthographical influences, and much more.

The Persian Lexicon Project: minimized orthographic neighbourhood effects in a dense language

In recent years large datasets of lexical processing times have been released for several languages, including English, French, Spanish, and Dutch. Such datasets have enabled us to study, compare, and model the global effects of many psycholinguistic measures such as word frequency, orthographic neighborhood (ON) size, and word length. We have compiled and publicly released a frequency and ON dictionary of 64,546 words and 1800 plausible NWs from a language that has been relatively little studied by psycholinguists: Persian. We have also collected visual lexical decision reaction times for 1800 Persian words and nonwords. Persian offers an interesting psycholinguistic environment for several reasons, including that it has few long words and has resultantly dense orthographic neighborhoods. These characteristics provide us with an opportunity to contrast how these factors affect lexical access by comparing them to several other languages. The results suggest that sensitivity to word length and orthographic neighbourhood may reflect the statistical structure of a particular language, rather than being a universal element of lexical processing. The dictionary and LDRT data are available from https://osf.io/tb4m6/ .

From decomposition to distributed theories of morphological processing in reading

The morphological structure of complex words impacts how they are processed during visual word recognition. This impact varies over the course of reading acquisition and for different languages and writing systems. Many theories of morphological processing rely on a decomposition mechanism, in which words are decomposed into explicit representations of their constituent morphemes. In distributed accounts, in contrast, morphological sensitivity arises from the tuning of finer-grained representations to useful statistical regularities in the form-to-meaning mapping, without the need for explicit morpheme representations. In this theoretically guided review, we summarize research into the mechanisms of morphological processing, and discuss findings within the context of decomposition and distributed accounts. Although many findings fit within a decomposition model of morphological processing, we suggest that the full range of results is more naturally explained by a distributed approach, and discuss additional benefits of adopting this perspective.

The Effect of Semantic Transparency in a Flanker Task

Abstract. This study tried to replicate and extend the semantic transparency morphological effect using the flanker lexical decision paradigm ( Grainger et al., 2020 ). In the first experiment, stems were used as flankers of target words that could be truly morphological ( hunt hunter hunt), pseudomorphological ( corn corner corn), or form-related with the flanker ( broth brothel broth). In half of the trials, a related flanker was employed, and in the other half, an unrelated word was presented as flanker (e.g., table player table). The results showed a facilitative effect for the related condition as a main effect with no difference between experimental conditions. These results were interpreted in terms of an orthographic facilitation taking place when whole stems are presented as flankers. In the second experiment, short derivational suffixes were used as flankers of the same targets employed in the first experiment. The results showed an inhibitory effect of the same magnitude for the transparent and pseudomorphological conditions with no effect for the form condition. This finding suggests an inhibitory effect by which morphemes activate several lexical candidates that compete for recognition. Overall, the results are interpreted in terms of the cognitive requirements of the experimental task, the items selected, and the current models of morphological processing.

The role of information theory for compound words in Mandarin Chinese and English

We investigate the role of information-theoretic measures for compound word reading in two languages: Mandarin Chinese and English. For each language, we report the results of two analyses: a time-to-event analysis using piece-wise additive mixed models (PAMMs) and a causal inference analysis with causal additive models (CAMs). We use the PAMM analyses to gain insight into the temporal profile of the effects of information-theoretic measures in the word naming task. For both English and Mandarin Chinese, we report early effects of the entropy of both constituents, as well as temporally widespread effects of point-wise mutual information (PMI). The CAM analyses provide further insight into the relations between lexical-distributional variables. The image that emerges from the CAM analyses is that the information-theoretic measures entropy and PMI are embedded in a carefully balanced system in which lexical-distributional properties that lead to processing difficulties are offset by lexical-distributional properties that guarantee successful communication. The information-theoretic measures have a central position in this system, and are causally influenced not only by frequency, but also by the effects of other lower-level lexical-distributional variables such as visual complexity, and phonology to orthography consistency.

CompLex: an eye-movement database of compound word reading in English

The CompLex database presents a large-scale collection of eye-movement studies on English compound-word processing. A combined total of 440 participants completed eye-tracking experiments in which they silently read unspaced English compound words (e.g., goalpost) embedded in sentence contexts (e.g., Dylan hit the goalpost when he was aiming for the net.). Three studies were conducted using participants representing the non-college-bound population (300 participants), and four studies included participants recruited from the student population (140 participants). The database comprises trial-level eye-movement data (47,763 trials), participant data (including a measure of reading experience estimated via the Author Recognition Test), and lexical characteristics for the set of 931 English compound words used as critical stimuli in the studies. One contribution of the present paper is a set of regression analyses conducted on the full database and individual experiments. We report that the most reliable and consistent main effects were those elicited by compound word length, left constituent frequency, right constituent frequency, compound frequency and semantic transparency. Separately, we also found that the effect of left frequency and compound word length is weaker among more frequent compounds. Another contribution is a power analysis, in which we determined the sample sizes required to reliably detect effect sizes that are comparable to those observed in our regression models. These sample size estimates serve as a recommendation for researchers wishing to either collect eye-movement data for compound word reading, or use the current database as a resource for the study of English compound word processing.

Morphological and visual cues in compound word reading: Eye-tracking evidence from Hebrew

Hebrew noun-noun compounds offer a valuable opportunity to study the long-standing question of how morphologically complex words are processed during reading. Specifically, in some morpho-syntactic environments, the first (head) noun of a compound carries a suffix-a clear orthographic marker of being part of a compound-whereas in others it is homographic with a stand-alone noun. In addition to this morphological cue, Hebrew occasionally employs hyphenation as a visual signal that two nouns, which are typically separated by a space, are combined in a compound. In a factorial design, we orthogonally manipulated the morphological and the visual cues and recorded eye movements of 75 proficient Hebrew readers while they read sentences with embedded compounds. The effect of hyphenation on reading times was inhibitory. This slow-down was significantly weaker in compounds where the syntactic relation between constituents was overtly marked by a suffix compared with compounds without a morphological marker. We interpret these findings as evidence that hyphenation is largely a redundant cue but morphological markers of compounding are psychologically valid cues for semantic integration of compounds. We discuss the implications of this finding for accounts of morphological processing.

Consistency measures individuate dissociating semantic modulations in priming paradigms: A new look on semantics in the processing of (complex) words

In human language the mapping between form and meaning is arbitrary, as there is no direct connection between words and the objects that they represent. However, within a given language, it is possible to recognise systematic associations that support productivity and comprehension. In this work, we focus on the consistency between orthographic forms and meaning, and we investigate how the cognitive system may exploit it to process words. We take morphology as our case study, since it arguably represents one of the most notable examples of systematicity in form-meaning mapping. In a series of three experiments, we investigate the impact of form-meaning mapping in word processing by testing new consistency metrics as predictors of priming magnitude in primed lexical decision. In Experiment 1, we re-analyse data from five masked morphological priming studies and show that orthography-semantics-consistency explains independent variance in priming magnitude, suggesting that word semantics is accessed already at early stages of word processing and that crucially semantic access is constrained by word orthography. In Experiments 2 and 3, we investigate whether this pattern is replicated when looking at semantic priming. In Experiment 2, we show that orthography-semantics-consistency is not a viable predictor of priming magnitude with longer stimulus onset asynchrony (SOA). However, in Experiment 3, we develop a new semantic consistency measure based on the semantic density of target neighbourhoods. This measure is shown to significantly predict independent variance in semantic priming effect. Overall, our results indicate that consistency measures provide crucial information for the understanding of word processing. Specifically, the dissociation between measures and priming paradigms shows that different priming conditions are associated with the activation of different semantic cohorts.

LADEC: The Large Database of English Compounds

The Large Database of English Compounds (LADEC) consists of over 8,000 English words that can be parsed into two constituents that are free morphemes, making it the largest existing database specifically for use in research on compound words. Both monomorphemic (e.g., wheel) and multimorphemic (e.g., teacher) constituents were used. The items were selected from a range of sources, including CELEX, the English Lexicon Project, the British Lexicon Project, the British National Corpus, and Wordnet, and were hand-coded as compounds (e.g., snowball). Participants rated each compound in terms of how predictable its meaning is from its parts, as well as the extent to which each constituent retains its meaning in the compound. In addition, we obtained linguistic characteristics that might influence compound processing (e.g., frequency, family size, and bigram frequency). To show the usefulness of the database in investigating compound processing, we conducted a number of analyses that showed that compound processing is consistently affected by semantic transparency, as well as by many of the other variables included in LADEC. We also showed that the effects of the variables associated with the two constituents are not symmetric. In short, LADEC provides the opportunity for researchers to investigate a number of questions about compounds that have not been possible to investigate in the past, due to the lack of sufficiently large and robust datasets. In addition to directly allowing researchers to test hypotheses using the information included in LADEC, the database will contribute to future compound research by allowing better stimulus selection and matching.

Psycholinguistic measures for German verb pairs: Semantic transparency, semantic relatedness, verb family size, and age of reading acquisition

A central issue in visual and spoken word recognition is the lexical representation of complex words-in particular, whether the lexical representation of complex words depends on semantic transparency: Is a complex verb like understand lexically represented as a whole word or via its base stand, given that its meaning is not transparent from the meanings of its parts? To study this issue, a number of stimulus characteristics are of interest that are not yet available in public databases of German. This article provides semantic association ratings, lexical paraphrases, and vector-based similarity measures for German verbs, measuring (a) the semantic transparency between 1,259 complex verbs and their bases, (b) the semantic relatedness between 1,109 verb pairs with 432 different bases, and (c) the vector-based similarity measures of 846 verb pairs. Additionally, we include the verb regularity of all verbs and two counts of verb family size for 184 base verbs, as well as estimates of age of acquisition and age of reading for 200 verbs. Together with lemma and type frequencies from public lexical databases, all measures can be downloaded along with this article. Statistical analyses indicate that verb family size, morphological complexity, frequency, and verb regularity affect the semantic transparency and relatedness ratings as well as the age of acquisition estimates, indicating that these are relevant variables in psycholinguistic experiments. Although lexical paraphrases, vector-based similarity measures, and semantic association ratings may deliver complementary information, the interrater reliability of the semantic association ratings for each verb pair provides valuable information when selecting stimuli for psycholinguistic experiments.

Skilled readers' sensitivity to meaningful regularities in English writing

Substantial research has been undertaken to understand the relationship between spelling and sound, but we know little about the relationship between spelling and meaning in alphabetic writing systems. We present a computational analysis of English writing in which we develop new constructs to describe this relationship. Diagnosticity captures the amount of meaningful information in a given spelling, whereas specificity estimates the degree of dispersion of this meaning across different spellings for a particular sound sequence. Using these two constructs, we demonstrate that particular suffix spellings tend to be reserved for particular meaningful functions. We then show across three paradigms (nonword classification, spelling, and eye tracking during sentence reading) that this form of regularity between spelling and meaning influences the behaviour of skilled readers, and that the degree of this behavioural sensitivity mirrors the strength of spelling-to-meaning regularities in the writing system. We close by arguing that English spelling may have become fractionated such that the high degree of spelling-sound inconsistency maximises the transmission of meaningful information.

Beyond decomposition: Processing zero-derivations in English visual word recognition

Four experiments investigate the effects of covert morphological complexity during visual word recognition. Zero-derivations occur in English in which a change of word class occurs without any change in surface form (e.g., a boat-to boat; to soak-a soak). Boat is object-derived and is a basic noun (N), whereas soak is action-derived and is a basic verb (V). As the suffix {-ing} is only attached to verbs, deriving boating from its base, requires two steps, boat(N) > boat(V) > boating(V), while soaking can be derived in one step from soak(V). Experiments 1 to 3 used masked priming at different prime durations to test matched sets of one- and two-step verbs for morphological (soaking-SOAK) and semantic priming (jolting-SOAK). Experiment 4 employed a delayed-priming paradigm in which the full verb forms (soaking and boating) were primed by noun and verb phrases (a soak/to soak, a boat/to boat). In both paradigms, different morphological priming patterns were observed for one-step and two-step verbs, demonstrating that morphological processing cannot be reduced to surface form-based segmentation.

Information and learning in processing adjective inflection

We investigated the processing of inflected Serbian adjective forms to bring together quantitative linguistic measures from two frameworks - information theory and discrimination learning. From each framework we derived several quantitative descriptions of an inflectional morphological system and fitted two separate regression models to the processing latencies that were elicited by inflected adjectival forms presented in a visual lexical decision task. The model, which was based on lexical distributional and information theory revealed a dynamic interplay of information. The information was sensitive to syntagmatic and paradigmatic dimensions of variation; the paradigmatic information (formalized as respective relative entropies) was also modulated by lemma frequency. The discrimination learning based model revealed an equally complex pattern, involving several learning-based variables. The two models revealed strikingly similar patterns of results, as confirmed by the very high proportion of shared variance in model predictions (85.83%). Our findings add to the body of research demonstrating that complex morphological phenomena can arise as a consequence of the basic principles of discrimination learning. Learning discriminatively about inflectional paradigms and classes, and about their contextual or syntagmatic embedding, sheds light on human language-processing efficiency and on the fascinating complexity of naturally emerged language systems.

Conceptual relations compete during auditory and visual compound word recognition

Previous research has shown that compound word recognition involves selecting a relational meaning (e.g., 'box for letters' for letterbox) out of a set of competing relational meanings for the same compound. We conducted five experiments to investigate the role of competition between relational meanings across visual and auditory compound word processing. In Experiment 1 conceptual relations judgments were collected for 604 English compound words. From this database we computed an information-theoretic measure of competition between conceptual relations - entropy of conceptual relations. Experiments 2 and 3 report that greater entropy (i.e., increased competition) among a set of conceptual relations leads to longer latencies for compounds in auditory lexical decision. Experiments 4 and 5 demonstrate the same result in two visual lexical decision studies. These findings provide evidence that relational meanings are constructed and evaluated during compound recognition, regardless of whether compounds are recognized via auditory or visual input.

How Children Become Sensitive to the Morphological Structure of the Words That They Read

Background: We tested the predictions of models of word reading development as to the effects of repeated exposure on reading of derived words. Aim: Our goal was to examine the impacts of variables that quantify different aspects of this exposure: base frequency, family frequency, and family size. Methods and Samples: In Experiment 1, we asked 75 children in Grades 3 and 5 to read derived words with low surface frequencies (e.g., questionable) that varied in base frequency, family frequency, and family size. In Experiment 2, we asked 41 adults to read the same set of words. Results: In Experiment 1, only base frequency made a contribution to word reading accuracy that was independent of the other two variables of interest (family size and family frequency) and the control variables (surface frequency, semantic relatedness, and neighborhood size). In Experiment 2, a similar pattern of results emerged, this time on reading speed. Conclusion: Together, results of these two studies suggest that base frequency has a special role in both children's and adults' reading of derived words. These findings suggest that it plays a specific role in development and maintenance of sensitivity to morphological structure in reading.

Age of acquisition and imageability norms for base and morphologically complex words in English and in Spanish

The extent to which processing words involves breaking them down into smaller units or morphemes or is the result of an interactive activation of other units, such as meanings, letters, and sounds (e.g., dis-agree-ment vs. disagreement), is currently under debate. Disentangling morphology from phonology and semantics is often a methodological challenge, because orthogonal manipulations are difficult to achieve (e.g., semantically unrelated words are often phonologically related: casual-casualty and, vice versa, sign-signal). The present norms provide a morphological classification of 3,263 suffixed derived words from two widely spoken languages: English (2,204 words) and Spanish (1,059 words). Morphologically complex words were sorted into four categories according to the nature of their relationship with the base word: phonologically transparent (friend-friendly), phonologically opaque (child-children), semantically transparent (habit-habitual), and semantically opaque (event-eventual). In addition, ratings were gathered for age of acquisition, imageability, and semantic distance (i.e., the extent to which the meaning of the complex derived form could be drawn from the meaning of its base constituents). The norms were completed by adding values for word frequency; word length in number of phonemes, letters, and syllables; lexical similarity, as measured by the number of neighbors; and morphological family size. A series of comparative analyses from the collated ratings for the base and derived words were also carried out. The results are discussed in relation to recent findings.

The Salience of Complex Words and Their Parts: Which Comes First?

This paper deals with the impact of the salience of complex words and their constituent parts on lexical access. While almost 40 years of psycholinguistic studies have focused on the relevance of morphological structure for word recognition, little attention has been devoted to the relationship between the word as a whole unit and its constituent morphemes. Depending on the theoretical approach adopted, complex words have been seen either in the light of their paradigmatic environment (i.e., from a paradigmatic view), or in terms of their internal structure (i.e., from a syntagmatic view). These two competing views have strongly determined the choice of experimental factors manipulated in studies on morphological processing (mainly different lexical frequencies, word/non-word structure, and morphological family size). Moreover, work on various kinds of more or less segmentable items (from genuinely morphologically complex words like hunter to words exhibiting only a surface morphological structure like corner and irregular forms like thieves) has given rise to two competing hypotheses on the cognitive role of morphology. The first hypothesis claims that morphology organizes whole words into morphological families and series, while the second sets morphology at a pre-lexical level, with morphemes standing as access units to the mental lexicon. The present paper examines more deeply the notion of morphological salience and its implications for theories and models of morphological processing.

The Role of Lexical Frequency in the Acceptability of Syntactic Variants: Evidence From that-Clauses in Polish

A number of studies report that frequency is a poor predictor of acceptability, in particular at the lower end of the frequency spectrum. Because acceptability judgments provide a substantial part of the empirical foundation of dominant linguistic traditions, understanding how acceptability relates to frequency, one of the most robust predictors of human performance, is crucial. The relation between low frequency and acceptability is investigated using corpus- and behavioral data on the distribution of infinitival and finite that-complements in Polish. Polish verbs exhibit substantial subordination variation and for the majority of verbs taking an infinitival complement, the that-complement occurs with low frequency (<0.66 ipm). These low-frequency that-clauses, in turn, exhibit large differences in how acceptable they are to native speakers. It is argued that acceptability judgments are based on configurations of internally structured exemplars, the acceptability of which cannot reliably be assessed until sufficient evidence about the core component has accumulated.

Computational Modeling of Morphological Effects in Bangla Visual Word Recognition

In this paper we aim to model the organization and processing of Bangla polymorphemic words in the mental lexicon. Our objective is to determine whether the mental lexicon accesses a polymorphemic word as a whole or decomposes the word into its constituent morphemes and then recognize them accordingly. To address this issue, we adopted two different strategies. First, we conduct a masked priming experiment over native speakers. Analysis of reaction time (RT) and error rates indicates that in general, morphologically derived words are accessed via decomposition process. Next, based on the collected RT data we have developed a computational model that can explain the processing phenomena of the access and representation of Bangla derivationally suffixed words. In order to do so, we first explored the individual roles of different linguistic features of a Bangla morphologically complex word and observed that processing of Bangla morphologically complex words depends upon several factors like, the base and surface word frequency, suffix type/token ratio, suffix family size and suffix productivity. Accordingly, we have proposed different feature models. Finally, we combine these feature models together and came up with a new model that takes the advantage of the individual feature models and successfully explain the processing phenomena of most of the Bangla morphologically derived words. Our proposed model shows an accuracy of around 80% which outperforms the other related frequency models.

The role of orthographic neighborhood size effects in Chinese word recognition

Previous studies about the orthographic neighborhood size (NS) in Chinese have overlooked the morphological processing, and the co-variation between the character frequency and the the NS. The present study manipulated the word frequency and the NS simultaneously, with the leading character frequency controlled, to explore their influences on word lexical decision (Experiment 1) and naming (Experiment 2). The results showed a robust effect that words with a larger NS produced shorter reaction time than those with a smaller NS, irrespective of the word frequency and the tasks. This facilitative effect may occur due to a semantic network formed by neighbor words, resulting in the semantic activation to accelerate the word recognition. Moreover, the comparison of the effect sizes of word frequency between the two tasks showed that lexical decision responses demonstrated a larger word frequency effect, indicating that the sub-word processing was involved in the multi-character word recognition.

Must analysis of meaning follow analysis of form? A time course analysis

Many models of word recognition assume that processing proceeds sequentially from analysis of form to analysis of meaning. In the context of morphological processing, this implies that morphemes are processed as units of form prior to any influence of their meanings. Some interpret the apparent absence of differences in recognition latencies to targets (SNEAK) in form and semantically similar (sneaky-SNEAK) and in form similar and semantically dissimilar (sneaker-SNEAK) prime contexts at a stimulus onset asynchrony (SOA) of 48 ms as consistent with this claim. To determine the time course over which degree of semantic similarity between morphologically structured primes and their targets influences recognition in the forward masked priming variant of the lexical decision paradigm, we compared facilitation for the same targets after semantically similar and dissimilar primes across a range of SOAs (34–100 ms). The effect of shared semantics on recognition latency increased linearly with SOA when long SOAs were intermixed (Experiments 1A and 1B) and latencies were significantly faster after semantically similar than dissimilar primes at homogeneous SOAs of 48 ms (Experiment 2) and 34 ms (Experiment 3). Results limit the scope of form-then-semantics models of recognition and demonstrate that semantics influences even the very early stages of recognition. Finally, once general performance across trials has been accounted for, we fail to provide evidence for individual differences in morphological processing that can be linked to measures of reading proficiency.

Cross-language activation of morphological relatives in cognates: the role of orthographic overlap and task-related processing

We considered the role of orthography and task-related processing mechanisms in the activation of morphologically related complex words during bilingual word processing. So far, it has only been shown that such morphologically related words (i.e., morphological family members) are activated through the semantic and morphological overlap they share with the target word. In this study, we investigated family size effects in Dutch-English identical cognates (e.g., tent in both languages), non-identical cognates (e.g., pil and pill, in English and Dutch, respectively), and non-cognates (e.g., chicken in English). Because of their cross-linguistic overlap in orthography, reading a cognate can result in activation of family members both languages. Cognates are therefore well-suited for studying mechanisms underlying bilingual activation of morphologically complex words. We investigated family size effects in an English lexical decision task and a Dutch-English language decision task, both performed by Dutch-English bilinguals. English lexical decision showed a facilitatory effect of English and Dutch family size on the processing of English-Dutch cognates relative to English non-cognates. These family size effects were not dependent on cognate type. In contrast, for language decision, in which a bilingual context is created, Dutch and English family size effects were inhibitory. Here, the combined family size of both languages turned out to better predict reaction time than the separate family size in Dutch or English. Moreover, the combined family size interacted with cognate type: the response to identical cognates was slowed by morphological family members in both languages. We conclude that (1) family size effects are sensitive to the task performed on the lexical items, and (2) depend on both semantic and formal aspects of bilingual word processing. We discuss various mechanisms that can explain the observed family size effects in a spreading activation framework.

The effects of base frequency and affix productivity in Spanish

In this study we present the results of a lexical decision experiment where the variables manipulated are Base frequency and Affix productivity. The results show significant main effects for both variables for the first time in Spanish, as well as for the interaction between the two. However, pair analysis shows that the Base Frequency effect is not significant when the Affix Productivity is low, while the Affix Productivity effect is produced regardless of the Base Frequency. The results for the main effects show a morphological representation in the lexicon, whilst the results of pair comparisons suggest a different representation of stems and affixes in the lexicon. These results support the idea that complex words incorporating unproductive affixes are processed differently from words incorporating productive affixes. The results are finally explained in terms of a hierarchical model of morphological processing.

The effect of family size on spanish simple and complex words

This study presents the results of three experiments in which the Family Size (FS) effect is explored. The first experiment is carried out with no prime on simple words. The second and third experiments are carried out with morphological priming on complex words. In the first experiment a facilitatory effect of FS is observed: high FS targets produced faster responses than low FS targets. However, an inhibitory effect of Stem-FS is observed in the second experiment: low Stem-FS targets produced faster responses than high Stem-FS targets. In the third experiment a facilitatory effect is observed when the Affix-FS is manipulated: high Affix-FS targets produced faster responses than low Affix-FS targets. Overall data confirms that the effect of FS plays an important role in lexical access in Spanish. The results also show that the effect of FS is modulated by the lexical nature of the prime (lexical or sublexical) and by the number of candidates activated. Finally, it is suggested that the nonwords employed were decisive in obtaining the results mentioned.

Effects of morphological Family Size for young readers

Dutch children, from the second and fourth grade of primary school, were each given a visual lexical decision test on 210 Dutch monomorphemic words. After removing words not recognized by a majority of the younger group, (lexical) decisions were analysed by mixed-model regression methods to see whether morphological Family Size influenced decision times over and above several other covariates. The effect of morphological Family Size on decision time was mixed: larger families led to significantly faster decision times for the second graders but not for the fourth graders. Since facilitative effects on decision times had been found for adults, we offer a developmental account to explain the absence of an effect of Family Size on decision times for fourth graders.

Proportion of categories of associates and structure of the mental lexicon

The aim of this study was to investigate whether there is a systematic distinction between associate pairs that constitute categories of lexical relations (e.g. synonyms, antonyms, hyponyms etc.) and categories of associate pairs that have no obvious lexical relation. Proportion of categories of associates were estimated on 80 nouns from "Associative Dictionary of Serbian Language" (Piper, Dragicevic & Stefanovic, 2005), while frequencies of associates were estimated from "Frequency Dictionary of Contemporary Serbian Language" (Kostic, Dj., 1999). Categories of associates were divided into two groups: group of categories that included standard lexical relations and group that included idiosyncratic associates. Proportions of categories were analyzed with respect to a) frequency of a noun to which associates were generated and b) whether it was an abstract or concrete noun. Three measures were used to estimate proportion of categories: a) number of associates, b) sum frequency of associates and c) the average frequency per associate. When estimated with respect to number of associates and sum frequency of associates proportion of categories that included standard lexical relations were negligible (6% and 18%), but they become dominant when estimated with respect to the average frequency per associate. Such an outcome suggests that categories that include standard lexical relations are characterized by small number of associates (due to the fact that they are closed classes) with high frequency associates. Distinction between abstract and concrete nouns did not affect number of associates per category, which was not the case when proportions were estimated with respect to sum frequency of associates. Frequency of a noun to which associates were generated has no effect on productivity of associates, nor does it affects sum frequency per category. However, it has significant effect on the average frequency per associate within a given category.

The effect of family size on processing Serbian nouns

In two lexical decision experiments the effect of family size was investigated for Serbian nouns. In the first experiment there were 15 nouns of low and 15 nouns of high family size, while in the second experiment 50 nouns that cover the whole range of family size spectrum were presented. In both experiments family size accounts for significant proportion of explained variance of response latencies. In multiple regression the effect of family size is significant over and above word frequency and word length, while frequency and word length do not account for significant proportion of variance over and above family size.

Allomorphic variation in Arabic: implications for lexical processing and representation

This study probes the effects of allomorphy on access to Arabic roots and word patterns in two cross-modal priming experiments. Experiment 1 used strong roots which undergo no allomorphy, and weak roots which undergo allomorphy and surface with only two of their three consonants in some derivations. Word pairs sharing a root morpheme prime each other reliably not only when the root was strong (e.g., [see text] participant/participate), but also when it was weak (e.g., [see text] agreement-agree, where the weak root [wfq] surfaces fully in the target but not the prime). This facilitation occurred even when the weak root surfaced with different semantic meanings across prime and target (e.g., [see text] destination/confront). Experiment 2 assessed the effects of allomorphy on word pattern processing, comparing word pairs where the word pattern is transparently realised in both prime and target (e.g., [see text] spread/bear], with pairs which share the same underlying word pattern but where a weak root triggers an assimilation process in the prime (e.g., [see text] unite/smile). This assimilation process does not disrupt the CV-structure of the word pattern, in contrast to a third condition where this is disrupted in both prime and target (e.g., [see text] turn around/say). Strong priming effects were observed in the first two conditions but not in the third. The bearing of these findings on models of lexical processing and representation is discussed.

Conceptions and questions concerning morphological processing

The understanding of the nature and extent of morphological processing is critical to the overall investigation of how words are organized in the mind. In this overview article, we discuss the nature of morphological processing and the domain of morphological processing research. We claim that investigations crucially involve the understanding of relations among morphologically simple and morphologically complex words, and sketch how specific questions of morphological processing within the 2004 special issue on the mental lexicon fall under these categories. Finally, we discuss issues of construct, content and ecological validity within the field and what morphological processing can reveal about the association of form and meaning in the mind.

What do graded effects of semantic transparency reveal about morphological processing?

We examined the influence of semantic transparency on morphological facilitation in English in three lexical decision experiments. Decision latencies to visual targets (e.g., CASUALNESS) were faster after semantically transparent (e.g., CASUALLY) than semantically opaque (e.g., CASUALTY) primes whether primes were auditory and presented immediately before onset of the target (Experiment 1a) or visual with an stimulus onset asynchrony (SOA) of 250 ms (Experiment 1b). Latencies did not differ at an SOA of 48 ms (Experiment 2) or with a forward mask at an SOA of 83 ms (Experiment 3). Generally, effects of semantic transparency among morphological relatives were evident at long but not at short SOAs with visual targets, regardless of prime modality. Moreover, the difference in facilitation after opaque and transparent primes was graded and increased with family size of the base morpheme.

Morphological processing: a comparison between free and bound stem facilitation

Linguists distinguish between words formed from free stems (e.g., actor: act) and those formed from bound stems (e.g., spectator: spect). In a forward masked priming task, we observed significant morphological facilitation for prime-target pairs that shared either a free (e.g., deform-CONFORM) or a bound (e.g., revive-SURVIVE) stem. Relative to an unrelated baseline, magnitudes of facilitation for free (e.g., form) and bound (e.g., vive) stems were significant and comparable, but relative to an orthographic baseline free stem facilitation was greater than bound stem facilitation. In addition, the magnitude of bound (but not free) stem morphological facilitation correlated with the number of morphological relatives.