Compound words and structure in the lexicon

Frequency effects can modulate the neural correlates of prosodic processing in Mandarin

In tonal languages, tone perception involves the processing of both acoustic and phonological information conveyed by tonal signals. In Mandarin, in addition to four canonical full tones, there exists a group of weak syllables known as neutral tones. This study aims to investigate the impact of lexical frequency effects and prosodic information associated with neutral tones on the auditory representation of Mandarin compounds. We initially selected disyllabic compounds as targets, manipulating their lexical frequencies and prosodic structures. Subsequently, these target compounds were embedded into selected sentences and auditorily presented to native speakers. During the experiments, participants engaged in lexical decision tasks while their event-related potentials were recorded. The results showed that the auditory lexical representation of disyllabic compounds was modulated by lexical frequency effects. Rare compounds and compounds with rare first constituents elicited larger N400 effects compared to frequent compounds. Furthermore, neutral tones were found to play a role in the processing, resulting in larger N400 effects. Our findings showed significantly increased amplitudes of the N400 component, suggesting that the processing of rare compounds and compounds with neutral tones may require more cognitive resources. Additionally, we observed an interaction effect between lexical frequency and neutral tones, indicating that they could serve as determining cues in the auditory processing of disyllabic compounds.

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.

Wolf-hound vs. sled-dog: neurolinguistic evidence for semantic decomposition in the recognition of German noun-noun compounds

Animacy is an intrinsic semantic property of words referring to living things. A long line of evidence shows that words with animate referents require lower processing costs during word recognition than words with inanimate referents, leading among others to a decreased N400 amplitude in reaction to animate relative to inanimate objects. In the current study, we use this animacy effect to provide evidence for access to the semantic properties of constituents in German noun-noun compounds. While morphological decomposition of noun-noun compounds is well-researched and illustrated by the robust influence of lexical constituent properties like constituent length and frequency, findings for semantic decomposition are less clear in the current literature. By manipulating the animacy of compound modifiers and heads, we are able to manipulate the relative ease of lexical access strictly due to intrinsic semantic properties of the constituents. Our results show additive effects of constituent animacy, with a higher number of animate constituents leading to gradually attenuated N400 amplitudes. We discuss the implications of our findings for current models of complex word recognition, as well as stimulus construction practices in psycho-and neurolinguistic research.

Visual event-related potentials reveal the early whole-word lexical processing of Chinese two-character words

Morphologically complex words are common across different languages, especially in Chinese, because more than 90% of common modern Chinese words are complex words. Many behavioral studies have suggested the whole-word processing of Chinese complex words, but the neural correlates of whole-word processing remain unclear. Previous electrophysiological studies revealed automatic and early (∼250 ms) access to the orthographic forms of monomorphic words in the ventral occipitotemporal area. In this study, we investigated whether there is also automatic and early orthographic recognition of Chinese complex words (as whole units) by recording event-related potentials (ERPs). A total of 150 two-character words and 150 two-character pseudowords composed of the same 300 characters (morphemes) were pseudorandomly presented to proficient Chinese readers. Participants were required to determine the color of each stimulus in the color decision task and to determine whether each stimulus was a word in the lexical decision task. The two constituent characters of each stimulus were horizontally arranged in Experiment 1 and vertically arranged in Experiment 2. The results revealed a significant early ERP difference between words and pseudowords approximately 250-300 ms after stimulus onset in the parieto-occipital scalp region. The early ERP difference was more prominent in the color decision task than in the lexical decision task, more prominent in Experiment 1 than in Experiment 2, and more prominent in the left parieto-occipital scalp region than in the right. Source analysis results showed that the early ERP difference originated from the left ventral occipitotemporal cortex. These results reflected early and automatic access to whole-word orthographic representations of Chinese complex words in the left ventral occipitotemporal cortex.

Sources of Heterogeneity in Functional Connectivity During English Word Processing in Bilingual and Monolingual Children

Diversity and variation in language experiences, such as bilingualism, contribute to heterogeneity in children's neural organization for language and brain development. To uncover sources of such heterogeneity in children's neural language networks, the present study examined the effects of bilingual proficiency on children's neural organization for language function. To do so, we took an innovative person-specific analytical approach to investigate young Chinese-English and Spanish-English bilingual learners of structurally distinct languages. Bilingual and English monolingual children (N = 152, M(SD)_age = 7.71(1.32)) completed an English word recognition task during functional near-infrared spectroscopy neuroimaging, along with language and literacy tasks in each of their languages. Two key findings emerged. First, bilinguals' heritage language proficiency (Chinese or Spanish) made a unique contribution to children's language network density. Second, the findings reveal common and unique patterns in children's patterns of task-related functional connectivity. Common across all participants were short-distance neural connections within left hemisphere regions associated with semantic processes (within middle temporal and frontal regions). Unique to more proficient language users were additional long-distance connections between frontal, temporal, and bilateral regions within the broader language network. The study informs neurodevelopmental theories of language by revealing the effects of heterogeneity in language proficiency and experiences on the structure and quality of emerging language neural networks in linguistically diverse learners.

Brain bases of English morphological processing: A comparison between Chinese-English, Spanish-English bilingual, and English monolingual children

How do early bilingual experiences influence children's neural architecture for word processing? Dual language acquisition can yield common influences that may be shared across different bilingual groups, as well as language-specific influences stemming from a given language pairing. To investigate these effects, we examined bilingual English speakers of Chinese or Spanish, and English monolinguals, all raised in the US (N = 152, ages 5-10). Children completed an English morphological word processing task during fNIRS neuroimaging. The findings revealed both language-specific and shared bilingual effects. The language-specific effects were that Chinese and Spanish bilinguals showed principled differences in their neural organization for English lexical morphology. The common bilingual effects shared by the two groups were that in both bilingual groups, increased home language proficiency was associated with stronger left superior temporal gyrus (STG) activation when processing the English word structures that are most dissimilar from the home language. The findings inform theories of language and brain development during the key periods of neural reorganization for learning to read by illuminating experience-based plasticity in linguistically diverse learners.

The neural basis of compound word processing revealed by varying semantic transparency and morphemic neighborhood size

This study investigated the neural basis of compound word processing by using fMRI and Chinese two-character compounds for lexical decision. Semantic transparency and morphemic neighborhood size were manipulated to augment the processing profile for measurement. The behavioral results disclosed a semantic transparency effect and its interaction with the neighborhood size, which supported existence of a mechanism for compound processing. The fMRI results located a neural substrate in the left inferior prefrontal cortex (BA 45) which reacted in an interactive manner to the two variables. While its activities were lower when their neighborhood size was larger for processing transparent compounds, its activities became higher when their neighborhood size was larger for processing opaque compounds. When scaling to a larger scope, the function of this mechanism fitted well with the theoretical account of unification function of the left inferior frontal cortex for language processing.

Psycholinguistic norms for a set of 506 French compound words

Compounds are morphologically complex words made of different linguistic parts. They are very prevalent in a number of languages such as French. Different psycholinguistic characteristics of compounds have been used in certain studies to investigate the mechanisms involved in compound processing (see Table 7). We provide psycholinguistic norms for a set of 506 French compound words. The words were normed on seven characteristics: lexeme meaning dominance, semantic transparency, sensory experience, conceptual familiarity, imageability, age of acquisition (AoA) and subjective frequency. Reliability measures were computed for the collected norms. Descriptive statistical analyses, and correlational and multiple regression analyses were performed. We also report some comparisons made between our normative data and certain norms obtained in other similar studies. The entire set of norms, which will be very useful to researchers investigating the processing of compounds, is available as Supplemental Material.

Opacity, Transparency, and Morphological Priming: A Study of Prefixed Verbs in Dutch

A basic question for the study of the mental lexicon is whether there are morphological representations and processes that are independent of phonology and semantics. According to a prominent tradition, morphological relatedness requires semantic transparency: semantically transparent words are related in meaning to their stems, while semantically opaque words are not. This study examines the question of morphological relatedness using intra-modal auditory priming by Dutch prefixed verbs. The key conditions involve semantically transparent prefixed primes (e.g., aanbieden 'offer', with the stem bieden, also 'offer') and opaque primes (e.g., verbieden 'forbid'). Results show robust facilitation for both transparent and opaque pairs; phonological (Experiment 1) and semantic (Experiment 2) controls rule out the possibility that these other types of relatedness are responsible for the observed priming effects. The finding of facilitation with opaque primes suggests that morphological processing is independent of semantic and phonological representations. Accordingly, the results are incompatible with theories that make semantic overlap a necessary condition for relatedness, and favor theories in which words may be related in ways that do not require shared meaning. The general discussion considers several specific proposals along these lines, and compares and contrasts questions about morphological relatedness of the type found here with the different but related question of whether there is morphological decomposition of complex forms or not.

How the brain composes morphemes into meaning

Morphemes (e.g. [tune], [-ful], [-ly]) are the basic blocks with which complex meaning is built. Here, I explore the critical role that morpho-syntactic rules play in forming the meaning of morphologically complex words, from two primary standpoints: (i) how semantically rich stem morphemes (e.g. explode, bake, post) combine with syntactic operators (e.g. -ion, -er, -age) to output a semantically predictable result; (ii) how this process can be understood in terms of mathematical operations, easily allowing the brain to generate representations of novel morphemes and comprehend novel words. With these ideas in mind, I offer a model of morphological processing that incorporates semantic and morpho-syntactic operations in service to meaning composition, and discuss how such a model could be implemented in the human brain. This article is part of the theme issue 'Towards mechanistic models of meaning composition'.

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.

Processing verb-noun compound words in Spanish: Evidence from event-related potentials

The following abstract contains 150 words: Studies regarding compound word processing have centred on Noun-noun words, which exhibit endocentricity. Nevertheless, other compound types, such as Spanish Verb-noun compounds, exhibit morphological particularities such as exocentricity, verb argument structure, and metaphorical features, increasing the attributes that may influence compound processing. We analysed whether these traits influenced Spanish Verb-noun compound processing. A lexical decision task was administrated with electroencephalogram (EEG) recording. Following differences in argument structure and metaphorical traits, three compound types were presented: Agentives, Locatives, and Metaphoricals. Locatives were responded worse and slower than Agentives. Metaphoricals elicited increases in the P300 and P600-like components. Thus, verb argument structure and metaphorical processes influence Spanish Verb-noun compound processing. Similarly to endocentric English Noun-noun compounds, processing Spanish Verb-noun compounds involves specific conceptual operations. These conceptual combinations appear to be determined by the projection of verb argument structure and the mapping and assignation of thematic roles.

Constituent frequency effects in the written production of Spanish compound words

The debate about whether compound words are accessed as whole words or via their constituents remains unresolved, especially in the field of language production. In this study, three experiments used a copying task to examine whether compound words are accessed via their constituents in handwriting production. In Experiment 1, production of compound words and noncompounds was compared. The last interletter interval within the first constituent of compounds was observed to be shorter than the same interval in noncompounds, revealing that writing durations are sensitive to morphological processing. In Experiments 2 and 3, the first and second constituent frequency was manipulated respectively. The frequency of both constituents affected writing onset times. Interestingly, the interval between the last two letters of the first constituent was shorter when the second constituent was of high frequency, suggesting that the effect obtained in this position in Experiment 1 was related to the anticipation of the second constituent. Our findings indicate that both constituents are activated before the initiation of the written response and that the second component is reactivated before the production of the first constituent has finished.

Age-related effects in compound production: Evidence from a double-object picture naming task

This study investigated effects of healthy ageing and of non-verbal attentional control on speech production. Young and older speakers participated in a picture-word interference (PWI) task with compound targets. To increase the processing load, the two pictures of the compounds’ constituents were presented side-by-side for spoken naming (e.g., a picture of a sun + a picture of a flower to be named with sunflower). Written distractors either corresponded to the first or second constituent ( sun or flower → sunflower), or were semantically related either to the first constituent of the target ( moon → sunflower) or to the second constituent/whole word ( tulip → sunflower). Morpho-phonological facilitation was obtained for both constituents, whereas semantic interference was restricted to first-constituent-related semantic distractors. Furthermore, a trend towards facilitation was obtained for distractors that were semantically related to the whole word. Older speakers were slower and produced more errors than young speakers. While morphological effects of first-constituent distractors were stronger for the elderly, the semantic effects were not affected by age. Non-verbal attentional control processes, measured in the Simon task, significantly contributed to morpho-phonological priming in the elderly, but they did not affect semantic interference or semantic facilitation. With a picture naming task that increases the semantic and lexical processing load, we corroborate earlier evidence that word-finding difficulties in the elderly result from deficient phonological encoding, whereas lexical-semantic and morpho-phonological representations remain stable with age.

Processing of Norwegian complex verbs: Evidence for early decomposition

We examined the processing of Norwegian complex verbs-compounds consisting of a prepositional prefix and a verbal root-to investigate the lexical decomposition of such morphologically complex compounds. In an eyetracking-while-reading study, we tested whether reading time measures were significantly predicted by a compound verb's whole-word frequency, its root family frequency, or some combination thereof. The results suggest that whole-word and root family frequencies make independent contributions to first-fixation durations. Subsequent reading time measures were better predicted by either whole-word frequency, root family frequency, or both in tandem. We interpret these results as providing support for hybrid models of lexical representation, in which complex verbs are associated with an atomic (whole-word) representation linked to the lexical entries for the compound's constituent morphemes.

A paradox of apparent brainless behavior: The time-course of compound word recognition

A review of the behavioral and neurophysiological estimates of the time-course of compound word recognition brings to light a paradox whereby temporal activity associated with lexical variables in behavioral studies predates temporal activity of seemingly comparable lexical processing in neuroimaging studies. However, under the assumption that brain activity is a cause of behavior, the earliest reliable behavioral effect of a lexical variable must represent an upper temporal bound for the origin of that effect in the neural record. The present research provides these behavioral bounds for lexical variables involved in compound word processing. We report data from five naturalistic reading studies in which participants read sentences containing English compound words, and apply a distributional technique of survival analysis to resulting eye-movement fixation durations (Reingold & Sheridan, 2014). The results of the survival analysis of the eye-movement record place a majority of the earliest discernible onsets of orthographic, morphological, and semantic effects at less than 200 ms (with a range of 138-269 ms). Our results place constraints on the absolute time-course of effects reported in the neurolinguistic literature, and support theories of complex word recognition which posit early simultaneous access of form and meaning.

The processing of blend words in naming and sentence reading

Research exploring the processing of morphologically complex words, such as compound words, has found that they are decomposed into their constituent parts during processing. Although much is known about the processing of compound words, very little is known about the processing of lexicalised blend words, which are created from parts of two words, often with phoneme overlap (e.g., brunch). In the current study, blends were matched with non-blend words on a variety of lexical characteristics, and blend processing was examined using two tasks: a naming task and an eye-tracking task that recorded eye movements during reading. Results showed that blend words were processed more slowly than non-blend control words in both tasks. Blend words led to longer reaction times in naming and longer processing times on several eye movement measures compared to non-blend words. This was especially true for blends that were long, rated low in word familiarity, but were easily recognisable as blends.

Grammatical-gender effects in noun–noun compound production: Evidence from German

We examined how noun–noun compounds and their syntactic properties are lexically stored and processed in speech production. Using gender-marked determiner primes ( dermasc, diefem, dasneut [the]) in a picture naming task, we tested for specific effects from determiners congruent with either the modifier or the head of the compound target (e.g., Teemasckannefem [teapot]) to examine whether the constituents are processed independently at the syntactic level. Experiment 1 assessed effects of auditory gender-marked determiner primes in bare noun picture naming, and Experiment 2 assessed effects of visual gender-marked determiner primes in determiner–noun picture naming. Three prime conditions were implemented: (a) head-congruent determiner (e.g., diefem), (b) modifier-congruent determiner (e.g., dermasc), and (c) incongruent determiner (e.g., dasneuter). We observed a facilitation effect of head congruency but no effect of modifier congruency. In Experiment 3, participants produced novel noun–noun compounds in response to two pictures, demanding independent processing of head and modifier at the syntactic level. Now, head and modifier congruency effects were obtained, demonstrating the general sensitivity of our task. Our data support the notion of a single-lemma representation of lexically stored compound nouns in the German production lexicon.

An Investigation into the Processing of Lexicalized English Blend Words: Evidence from Lexical Decisions and Eye Movements During Reading

New words enter the language through several word formation processes [see Simonini (Engl J 55:752-757, 1966)]. One such process, blending, occurs when two source words are combined to represent a new concept (e.g., SMOG, BRUNCH, BLOG, and INFOMERCIAL). While there have been examinations of the structure of blends [see Gries (Linguistics 42:639-667, 2004) and Lehrer (Am Speech 73:3-28, 1998)], relatively little attention has been given to how lexicalized blends are recognized and if this process differs from other types of words. In the present study, blend words were matched to non-blend control words on length, familiarity, and frequency. Two tasks were used to examine blend processing: lexical decision and sentence reading. The results demonstrated that blend words were processed differently than non-blend control words. However, the nature of the effect varied as a function of task demands. Blends were recognized slower than control words in the lexical decision task but received shorter fixation durations when embedded in sentences.

Competition between conceptual relations affects compound recognition: the role of entropy

Previous research has suggested that the conceptual representation of a compound is based on a relational structure linking the compound's constituents. Existing accounts of the visual recognition of modifier-head or noun-noun compounds posit that the process involves the selection of a relational structure out of a set of competing relational structures associated with the same compound. In this article, we employ the information-theoretic metric of entropy to gauge relational competition and investigate its effect on the visual identification of established English compounds. The data from two lexical decision megastudies indicates that greater entropy (i.e., increased competition) in a set of conceptual relations associated with a compound is associated with longer lexical decision latencies. This finding indicates that there exists competition between potential meanings associated with the same complex word form. We provide empirical support for conceptual composition during compound word processing in a model that incorporates the effect of the integration of co-activated and competing relational information.

Do Morphemes Matter when Reading Compound Words with Transposed Letters? Evidence from Eye-Tracking and Event-Related Potentials

The current study investigates the online processing consequences of encountering compound words with transposed letters (TLs), to determine if TLs that cross morpheme boundaries are more disruptive to reading than those within a single morpheme, as would be predicted by accounts of obligatory morpho-orthopgrahic decomposition. Two measures of online processing, eye movements and event-related potentials (ERPs), were collected in separate experiments. Participants read sentences containing correctly spelled compound words (cupcake), or compounds with TLs occurring either across morpheme boundaries (cucpake) or within one morpheme (cupacke). Results showed that between- and within-morpheme transpositions produced equal processing costs in both measures, in the form of longer reading times (Experiment 1) and a late posterior positivity (Experiment 2) that did not differ between conditions. Findings converge to suggest that within- and between-morpheme TLs are equally disruptive to recognition, providing evidence against obligatory morpho-orthographic processing and in favor of whole-word access of English compound words during sentence reading.

A database of 629 English compound words: ratings of familiarity, lexeme meaning dominance, semantic transparency, age of acquisition, imageability, and sensory experience

Since the work of Taft and Forster (1976), a growing literature has examined how English compound words are recognized and organized in the mental lexicon. Much of this research has focused on whether compound words are decomposed during recognition by manipulating the word frequencies of their lexemes. However, many variables may impact morphological processing, including relational semantic variables such as semantic transparency, as well as additional form-related and semantic variables. In the present study, ratings were collected on 629 English compound words for six variables [familiarity, age of acquisition (AoA), semantic transparency, lexeme meaning dominance (LMD), imageability, and sensory experience ratings (SER)]. All of the compound words selected for this study are contained within the English Lexicon Project (Balota et al., 2007), which made it possible to use a regression approach to examine the predictive power of these variables for lexical decision and word naming performance. Analyses indicated that familiarity, AoA, imageability, and SER were all significant predictors of both lexical decision and word naming performance when they were added separately to a model containing the length and frequency of the compounds, as well as the lexeme frequencies. In addition, rated semantic transparency also predicted lexical decision performance. The database of English compound words should be beneficial to word recognition researchers who are interested in selecting items for experiments on compound words, and it will also allow researchers to conduct further analyses using the available data combined with word recognition times included in the English Lexicon Project.

Morphological Decomposition in Reading Hebrew Homographs

The present work investigates whether and how morphological decomposition processes bias the reading of Hebrew heterophonic homographs, i.e., unique orthographic patterns that are associated with two separate phonological, semantic entities depicted by means of two morphological structures (linear and nonlinear). In order to reveal the nature of morphological processes involved in the reading of Hebrew homographs, we tested 146 university students with three computerized experiments, each experiment focusing on a different level of processing. Participants were divided into three experimental groups given that the three experiments used the same stimulus lists. Evidence obtained from the analysis of the participants' processing time and processing accuracy points to a propensity to process heterophonic homographs by default as morpho-syntactically simple rather than complex words. Findings are discussed with reference to assumptions made by Dual-Route models regarding the importance of morphological knowledge in fast and accurate access of written words' representations which mediate the retrieval of their meanings with direct reference to the context in which they occur.

Towards a computational(ist) neurobiology of language: Correlational, integrated, and explanatory neurolinguistics

We outline what an integrated approach to language research that connects experimental, theoretical, and neurobiological domains of inquiry would look like, and ask to what extent unification is possible across domains. At the center of the program is the idea that computational/representational (CR) theories of language must be used to investigate its neurobiological (NB) foundations. We consider different ways in which CR and NB might be connected. These are (1) A Correlational way, in which NB computation is correlated with the CR theory; (2) An Integrated way, in which NB data provide crucial evidence for choosing among CR theories; and (3) an Explanatory way, in which properties of NB explain why a CR theory is the way it is. We examine various questions concerning the prospects for Explanatory connections in particular, including to what extent it makes sense to say that NB could be specialized for particular computations.

Morphological structure processing during word recognition and its relationship to character reading among third-grade Chinese children

In the present study, we explored the characteristics of morphological structure processing during word recognition among third grade Chinese children and its possible relationship with Chinese character reading. By using the modified priming lexical decision paradigm, a significant morphological structure priming effect was found in the subject analysis when reaction time difference was considered as dependent variable. In the regression analyses, the children's implicit morphological structure processing demonstrated a significant effect on Chinese character reading, even though its effect became non-significant when morphological awareness was entered. We achieved this result after controlling for the children's age, non-verbal intelligence, and phonological awareness. These findings indicate that third grade Chinese children are sensitive to morphological structure information in the processing of compound words. Moreover, such sensitivity is, to some extent, a good predictor of Chinese children's word reading performance.

Real-time Functional Architecture of Visual Word Recognition

Despite a century of research into visual word recognition, basic questions remain unresolved about the functional architecture of the process that maps visual inputs from orthographic analysis onto lexical form and meaning and about the units of analysis in terms of which these processes are conducted. Here we use magnetoencephalography, supported by a masked priming behavioral study, to address these questions using contrasting sets of simple (walk), complex (swimmer), and pseudo-complex (corner) forms. Early analyses of orthographic structure, detectable in bilateral posterior temporal regions within a 150–230 msec time frame, are shown to segment the visual input into linguistic substrings (words and morphemes) that trigger lexical access in left middle temporal locations from 300 msec. These are primarily feedforward processes and are not initially constrained by lexical-level variables. Lexical constraints become significant from 390 msec, in both simple and complex words, with increased processing of pseudowords and pseudo-complex forms. These results, consistent with morpho-orthographic models based on masked priming data, map out the real-time functional architecture of visual word recognition, establishing basic feedforward processing relationships between orthographic form, morphological structure, and lexical meaning.

The role of morphology in phoneme prediction: evidence from MEG

There is substantial neural evidence for the role of morphology (word-internal structure) in visual word recognition. We extend this work to auditory word recognition, drawing on recent evidence that phoneme prediction is central to this process. In a magnetoencephalography (MEG) study, we crossed morphological complexity (bruis-er vs. bourbon) with the predictability of the word ending (bourbon vs. burble). High prediction error (surprisal) led to increased auditory cortex activity. This effect was enhanced for morphologically complex words. Additionally, we calculated for each timepoint the surprisal corresponding to the phoneme perceived at that timepoint, as well as the cohort entropy, which quantifies the competition among words compatible with the string prefix up to that timepoint. Higher surprisal increased neural activity at the end of the word, and higher entropy decreased neural activity shortly after word onset. These results reinforce the role of morphology and phoneme prediction in spoken word recognition.

Word-specific repetition effects revealed by MEG and the implications for lexical access

This magnetoencephalography (MEG) study investigated the early stages of lexical access in reading, with the goal of establishing when initial contact with lexical information takes place. We identified two candidate evoked responses that could reflect this processing stage: the occipitotemporal N170/M170 and the frontocentral P2. Using a repetition priming paradigm in which long and variable lags were used to reduce the predictability of each repetition, we found that (i) repetition of words, but not pseudowords, evoked a differential bilateral frontal response in the 150-250ms window, (ii) a differential repetition N400m effect was observed between words and pseudowords. We argue that this frontal response, an MEG correlate of the P2 identified in ERP studies, reflects early access to long-term memory representations, which we tentatively characterize as being modality-specific.

Electrophysiological evidence for the morpheme-based combinatoric processing of English compounds

The extent to which the processing of compounds (e.g., "catfish") makes recourse to morphological-level representations remains a matter of debate. Moreover, positing a morpheme-level route to complex word recognition entails not only access to morphological constituents, but also combinatoric processes operating on the constituent representations; however, the neurophysiological mechanisms subserving decomposition, and in particular morpheme combination, have yet to be fully elucidated. The current study presents electrophysiological evidence for the morpheme-based processing of both lexicalized (e.g., "teacup") and novel (e.g., "tombnote") visually presented English compounds; these brain responses appear prior to and are dissociable from the eventual overt lexical decision response. The electrophysiological results reveal increased negativities for conditions with compound structure, including effects shared by lexicalized and novel compounds, as well as effects unique to each compound type, which may be related to aspects of morpheme combination. These findings support models positing across-the-board morphological decomposition, counter to models proposing that putatively complex words are primarily or solely processed as undecomposed representations, and motivate further electrophysiological research toward a more precise characterization of the nature and neurophysiological instantiation of complex word recognition.

ERPs and morphological processing: the N400 and semantic composition

Both behavioral and electrophysiological evidence suggests that fluent readers decompose morphologically complex words into their constituent parts. Previous event-related potential (ERP) research has been equivocal with regard to whether the N400 component indexes morphological decomposition or the integration of the products of decomposition, a process called semantic composition. In a visual lexical decision task with college students, we recorded ERPs to a well-controlled set of words and nonwords made up of bound morphemes (discern, predict; disject, percern) or free morphemes (cobweb, earring; cobline, bobweb) and monomorphemic control words and nonwords (garlic, minnow; gartus, buzlic). For each of the three morphological types, participants were faster to respond to words than to nonwords. Furthermore, for each of the three morphological types, the amplitude of the N400 was more negative to nonwords than to matched words, an effect indicating that the N400 is more sensitive to the lexicality of the whole stimulus than to the meaningfulness of the constituent parts of the stimulus. The N400 lexicality effect was not significantly different across the three morphological types. To our knowledge, this is the first ERP study to directly compare the processing of printed sets of words composed of bound and free morphemes and monomorphemic control stimuli in order to explore the relative sensitivity of the N400 to morphological decomposition (i.e., the status of the parts) and semantic composition (i.e., the status of the whole). Our findings are consistent with an interpretation of the N400 as an index of a process of semantic composition.

Multiple routes for compound word processing in the brain: evidence from EEG

Are compound words represented as unitary lexical units, or as individual constituents that are processed combinatorially? We investigated the neuro-cognitive processing of compounds using EEG and a passive-listening oddball design in which lexical access and combinatorial processing elicit dissociating Mismatch Negativity (MMN) brain-response patterns. MMN amplitude varied with compound frequency and semantic transparency (the clarity of the relationship between compound and constituent meanings). Opaque compounds elicited an enhanced 'lexical' MMN, reflecting stronger lexical representations, to high- vs. low-frequency compounds. Transparent compounds showed no frequency effect, nor differed to pseudo-compounds, reflecting the combination of a reduced 'syntactic' MMN indexing combinatorial links, and an enhanced 'lexical' MMN for real-word compounds compared to pseudo-compounds. We argue that transparent compounds are processed combinatorially alongside parallel lexical access of the whole-form representation, but whole-form access is the dominant mechanism for opaque compounds, particularly those of high-frequency. Results support a flexible dual-route account of compound processing.

Lexical decision and the number of morphemes and affixes

There has been a considerable amount of research looking at the effects of both syllable number and syllable frequency on lexical decision and word naming times. Recently, there has also been an increased interest in morphological variables, but there have been no large scale studies that have examined the role of the number of morphemes in lexical decision for nonwords. This is partly because of the difficulty of identifying morphemes in nonwords. We present a program that identifies the presence of affixes and, therefore, can be used to count the number of morpheme-like elements in a nonword. We then used the program to measure the importance of affixes/morphemes in predicting lexical decision in nonwords. The results suggested that morphemes have an important role in lexical decision for both words and nonwords.

Understanding the mental lexicon through neglect dyslexia: a study on compound noun reading

The present study employs neglect dyslexia (ND) as an experimental model to study compound-word processing; in particular, it investigates whether compound constituents are hierarchically organized at mental level and addresses the possibility of whole-word representation. Seven Italian-speaking patients suffering from ND participated in a word naming task. Both left-headed (pescespada, swordfish) and right-headed (astronave, spaceship) Italian compound nouns were used as stimuli. Non-existent compounds, which were generated by substituting the leftmost constituent of a compound with an orthographically similar word (e.g., *pestespada, *plaguesword), were also employed. A significant headedness effect emerged in the group analysis: patients read left-headed compounds better than right-headed compounds. A significant lexicality effect was also found: the participants read real compounds better than their non-existent compound pairs. Moreover, logit mixed-effects analyses indicated a left-hand constituent frequency effect. Results are discussed in terms of hierarchical representation of compounds and direct access to compound lemma nodes.

The interface between morphology and phonology: exploring a morpho-phonological deficit in spoken production

Morphological and phonological processes are tightly interrelated in spoken production. During processing, morphological processes must combine the phonological content of individual morphemes to produce a phonological representation that is suitable for driving phonological processing. Further, morpheme assembly frequently causes changes in a word's phonological well-formedness that must be addressed by the phonology. We report the case of an aphasic individual (WRG) who exhibits an impairment at the morpho-phonological interface. WRG was tested on his ability to produce phonologically complex sequences (specifically, coda clusters of varying sonority) in heteromorphemic and tautomorphemic environments. WRG made phonological errors that reduced coda sonority complexity in multimorphemic words (e.g., passed→[pæstıd]) but not in monomorphemic words (e.g., past). WRG also made similar insertion errors to repair stress clash in multimorphemic environments, confirming his sensitivity to cross-morpheme well-formedness. We propose that this pattern of performance is the result of an intact phonological grammar acting over the phonological content of morphemic representations that were weakly joined because of brain damage. WRG may constitute the first case of a morpho-phonological impairment-these results suggest that the processes that combine morphemes constitute a crucial component of morpho-phonological processing.

The Role of Hyphens at the Constituent Boundary in Compound Word Identification

The current eye-movement study investigated whether a salient segmentation cue like the hyphen facilitates the identification of long and short compound words. The study was conducted in Finnish, where compound words exist in great abundance. The results showed that long hyphenated compounds (musiikki-ilta) are identified faster than concatenated ones (yllätystulos), but short hyphenated compounds (ilta-asu) are identified slower than their concatenated counterparts (kesäsää). This pattern of results is explained by the visual acuity principle ( Bertram & Hyönä, 2003 ): A long compound word does not fully fit in the foveal area, where visual acuity is at its best. Therefore, its identification begins with the access of the initial constituent and this sequential processing is facilitated by the hyphen. However, a short compound word fits in the foveal area, and consequently the hyphen slows down processing by encouraging sequential processing in cases where it is possible to extract and use information of the second constituent as well.

Compound nouns in spoken language production by speakers with aphasia compared to neurologically healthy speakers: an exploratory study

Compounds are words that are made up of at least two other words (lexemes), featuring lexical and syntactic characteristics and thus particularly interesting for the study of language processing. Most studies of compounds and language processing have been based on data from experimental single word production and comprehension tasks. To enhance the ecological validity of morphological processing research, data from other contexts, such as discourse production, need to be considered. This study investigates the production of nominal compounds in semi-spontaneous spoken texts by a group of speakers with fluent types of aphasia compared to a group of neurologically healthy speakers. The speakers with aphasia produce significantly fewer nominal compound types in their texts than the non-aphasic speakers, and the compounds they produce exhibit fewer different types of semantic relations than the compounds produced by the non-aphasic speakers. The results are discussed in relation to theories of language processing.

Evidence for early morphological decomposition: combining masked priming with magnetoencephalography

Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked morphological priming with magneto-encephalography (MEG), a technique particularly adept at indexing processes involved in lexical access. The latency of an MEG component peaking, on average, 220 msec post-onset of the target in left occipito-temporal brain regions was found to be sensitive to the morphological prime-target relationship under masked priming conditions in a visual lexical decision task. Shorter latencies for related than unrelated conditions were observed both for semantically transparent (cleaner-CLEAN) and opaque (corner-CORN) prime-target pairs, but not for prime-target pairs with only an orthographic relationship (brothel-BROTH). These effects are likely to reflect a prelexical level of processing where form-based representations of stems and affixes are represented and are in contrast to models positing no morphological structure in lexical representations. Moreover, we present data regarding the transitional probability from stem to affix in a post hoc comparison, which suggests that this factor may modulate early morphological decomposition, particularly for opaque words. The timing of a robust MEG component sensitive to the morphological relatedness of prime-target pairs can be used to further understand the neural substrates and the time course of lexical processing.

Parafoveal processing during reading is reduced across a morphological boundary

A boundary change manipulation was implemented within a monomorphemic word (e.g., fountaom as a preview for fountain), where parallel processing should occur given adequate visual acuity, and within an unspaced compound (bathroan as a preview for bathroom), where some serial processing of the constituents is likely. Consistent with that hypothesis, there was no effect of the preview manipulation on fixation time on the 1st constituent of the compound, whereas there was on the corresponding letters of the monomorphemic word. There was also a larger preview disruption on gaze duration on the whole monomorphemic word than on the compound, suggesting more parallel processing within monomorphemic words.

What does the right hemisphere know about phoneme categories?

Innate auditory sensitivities and familiarity with the sounds of language give rise to clear influences of phonemic categories on adult perception of speech. With few exceptions, current models endorse highly left-hemisphere-lateralized mechanisms responsible for the influence of phonemic category on speech perception, based primarily on results from functional imaging and brain-lesion studies. Here we directly test the hypothesis that the right hemisphere does not engage in phonemic analysis. By using fMRI to identify cortical sites sensitive to phonemes in both word and pronounceable nonword contexts, we find evidence that right-hemisphere phonemic sensitivity is limited to a lexical context. We extend the interpretation of these fMRI results through the study of an individual with a left-hemisphere lesion who is right-hemisphere reliant for initial acoustic and phonetic analysis of speech. This individual's performance revealed that the right hemisphere alone was insufficient to allow for typical phonemic category effects but did support the processing of gradient phonetic information in lexical contexts. Taken together, these findings confirm previous claims that the right temporal cortex does not play a primary role in phoneme processing, but they also indicate that lexical context may modulate the involvement of a right hemisphere largely tuned for less abstract dimensions of the speech signal.

Processing of existing, synonymous, and anomalous German derived adjectives: an MEG study

Neuronal activation as response to reading existing derived German adjectives (e.g., freundlich, friendly) was measured using MEG and compared to that evoked by non-existing, but semantically synonymous adjectives (*freundhaft) and to activation induced by non-existing, semantically and morphologically anomalous adjectives (*freundbar). By applying distributed source modeling we revealed a gradual increase of neuronal activity within areas of the left temporal lobe in the time range of the N400. Activity increased from existing over synonymous to anomalous adjectives. Underscoring the use of neurophysiological measures, these results demonstrate that morpho-semantic analysis take place for non-existing morphologically complex pseudowords even if not warranted by the current task. Furthermore, these data argue in favor of morphological decomposition.