Morphological priming effect: the role of surface frequency

Decomposability and mental representation of French verbs

In French, regardless of stem regularity, inflectional verbal suffixes are extremely regular and paradigmatic. Considering the complexity of the French verbal system, we argue that all French verbs are polymorphemic forms that are decomposed during visual recognition independently of their stem regularity. We conducted a behavioral experiment in which we manipulated the surface and cumulative frequencies of verbal inflected forms and asked participants to perform a visual lexical decision task. We tested four types of verbs with respect to their stem variants: a. fully regular (parler “to speak,” [parl-]); b. phonological change e/E verbs with orthographic markers (répéter “to repeat,” [répét-] and [répèt-]); c. phonological change o/O verbs without orthographic markers (adorer “to adore,” [ador-] and [adOr-]); and d. idiosyncratic (boire “to drink,” [boi-] and [buv-]). For each type of verb, we contrasted four conditions, forms with high and low surface frequencies and forms with high and low cumulative frequencies. Our results showed a significant cumulative frequency effect for the fully regular and idiosyncratic verbs, indicating that different stems within idiosyncratic verbs (such as [boi-] and [buv-]) have distinct representations in the mental lexicon as different fully regular verbs. For the phonological change verbs, we found a significant cumulative frequency effect only when considering the two forms of the stem together ([répét-] and [répèt-]), suggesting that they share a single abstract and under specified phonological representation. Our results also revealed a significant surface frequency effect for all types of verbs, which may reflect the recombination of the stem lexical representation with the functional information of the suffixes. Overall, these results indicate that all inflected verbal forms in French are decomposed during visual recognition and that this process could be due to the regularities of the French inflectional verbal suffixes.

Are dyslexic children sensitive to the morphological structure of words when they read? The case of dyslexic readers of French

Typically, research has cited a deficient use of word recognition procedures mainly caused by a phonological deficit as the source of dyslexic students' reading difficulties. However, recent studies have shown that morphological processing also plays an important part in reading. In the present study, sensitivity to the morphological structure of words was assessed with a plausibility judgment task, where participants determined which of two pseudo-words most resembled a real word in French, and with a decomposition task requiring participants to extract the base forms of morphologically complex words. Dyslexic participants (DYS, n = 26) aged 9-12 years were matched to 26 participants of the same chronological age (CA) and 30 younger participants of the same reading age (RA). Overall, the decomposition task was less successful at demonstrating morphological knowledge than the plausibility judgment task. Results indicate that dyslexic participants demonstrated some morphological sensitivity, particularly on the plausibility task, but were outperformed by both control groups on both tasks. Performance on morphological tasks was significantly correlated to reading comprehension scores. More research needs to be carried out to better comprehend the effects of task characteristics on dyslexic participants' success and before claiming a different or deviant developmental path for morphological knowledge.

Morphological processing as we know it: an analytical review of morphological effects in visual word identification

The last 40 years have witnessed a growing interest in the mechanisms underlying the visual identification of complex words. A large amount of experimental data has been amassed, but although a growing number of studies are proposing explicit theoretical models for their data, no comprehensive theory has gained substantial agreement among scholars in the field. We believe that this is due, at least in part, to the presence of several controversial pieces of evidence in the literature and, consequently, to the lack of a well-defined set of experimental facts that any theory should be able to explain. With this review, we aim to delineate the state of the art in the research on the visual identification of complex words. By reviewing major empirical evidences in a number of different paradigms such as lexical decision, word naming, and masked and unmasked priming, we were able to identify a series of effects that we judge as reliable or that were consistently replicated in different experiments, along with some more controversial data, which we have tried to resolve and explain. We concentrated on behavioral and electrophysiological studies on inflected, derived, and compound words, so as to span over all types of complex words. The outcome of this work is an analytical summary of well-established facts on the most relevant morphological issues, such as regularity, morpheme position coding, family size, semantic transparency, morpheme frequency, suffix allomorphy, and productivity, morphological entropy, and morpho-orthographic parsing. In discussing this set of benchmark effects, we have drawn some methodological considerations on why contrasting evidence might have emerged, and have tried to delineate a target list for the construction of a new all-inclusive model of the visual identification of morphologically complex words.

The Role of the Striatum in Processing Language Rules: Evidence from Word Perception in Huntington's Disease

On the assumption that linguistic faculties reflect both lexical storage in the temporal cortex and combinatorial rules in the striatal circuits, several authors have shown that striatal-damaged patients are impaired with conjugation rules while retaining lexical knowledge of irregular verbs [Teichmann, M., Dupoux, E., Kouider, S., Brugières, P., Boissé, M. F., Baudic, S., Cesaro, P., Peschanski, M., & Bachoud-Lévi, A. C. (2005). The role of the striatum in rule application. The model of Huntington's disease at early stage. Brain, 128, 1155–1167; Ullman, M. T., Corkin, S., Coppola, M., Hickok, G., Growdon, J. H., Koroshetz, W. J., & Pinker, S. (1997). A neural dissociation within language: Evidence that the mental dictionary is part of declarative memory, and that grammatical rules are processed by the procedural system. Journal of Cognitive Neuroscience, 9, 266–276]. Yet, such impairment was documented only with explicit conjugation tasks in the production domain. Little is known about whether it generalizes to other language modalities such as perception and whether it refers to implicit language processing or rather to intentional rule operations through executive functions. We investigated these issues by assessing perceptive processing of conjugated verb forms in a model of striatal dysfunction, namely, in Huntington's Disease (HD) at early stages. Rule application and lexical processes were evaluated in an explicit task (acceptability judgments on verb and nonword forms) and in an implicit task (lexical decision on frequency-manipulated verb forms). HD patients were also assessed in executive functions, and striatal atrophy was evaluated with magnetic resonance imaging (bicaudate ratio). Results from both tasks showed that HD patients were selectively impaired for rule application but lexical abilities were spared. Bicaudate ratios correlated with rule scores on both tasks, whereas executive parameters only correlated with scores on the explicit task. We argue that the striatum has a core function in linguistic rule application generalizing to perceptive aspects of morphological operations and pertaining to implicit language processes. In addition, we suggest that the striatum may enclose computational circuits that underpin explicit manipulation of regularities.

Schemas and competing paradigms in Swedish plural formation

According to autonomous descriptions of Swedish morphology, for the majority of nouns the gender of the lexeme and the phonological nature of the last segment or segments of the base form (indefinite singular) determine the inflectional category of the noun. The purpose of the present study is to find out if Swedish may resort to the use of larger shapes than the terminal segment or segments in the allegedly ambiguous monosyllabic CVC words. It has been shown in other languages-here giving English as an example-that items in semiproductive classes (like the English ablaut verbs string:strung and spin:spun) are associated via formal phonological links or bundles of links that constrain the manner in which native speakers pattern these form-to-form connections within morphological paradigms (see Bybee & Slobin, 1982; Bybee, 1985). The present wug-type experiment with legal nonwords was administered to three groups of children, i.e., 8- to 9-year-olds, 10- to 11-year-olds, and 15-year-olds. It was hypothesized that the ambiguous monosyllabic CVC lexemes would stabilize themselves slowly and late during language acquisition. The results show a vowel and consonant effect in the en-gender CVC nonwords. Swedish thus resorts to the use of larger shapes (schema analogies) than the terminal segment or segments. Moreover, a development of paradigm membership toward adultlike patterns is seen at late stages of language acquisition of both the ambiguous and the unambiguous nonword types.

Cross-modal morphological priming in French

We investigated the lexical representation of morphologically complex words in French using a cross-modal priming experiment. We asked if the lexical representation for derivationally suffixed and prefixed words is morphologically structured and how this relates to the phonological transparency of the surface relationship between stem and affix. Overall we observed a clear effect of the morphological structure for derived words, an effect that is not explicable by a formal effect. Prefixed words prime their stems, even when they have a phonologically opaque relationship, and a prefixed word primes another prefixed word derived from the same stem. However, suffixed words prime their stems only if their relationship is phonologically transparent. Two suffixed words derived from the same stem prime each other. These two latter results differ from those observed in English by Marslen-Wilson, Tyler, Waksler, and Older (1994). We argue that it is the specific properties of the language, such as rhythm, that could explain the differences between the results observed for the two languages and we propose a model where prefixed and suffixed words are decomposed at different stages during their identification process.

Does prime modality influence morphological processing?

Facilitation among morphologically related words generally is impervious to the prefixed or suffixed structure of primes and targets. A notable exception arises, however, when both primes and targets are suffixed. More specifically, when primes are auditory and targets are visual, facilitation for a suffixed target (e.g., payment) is absent when it follows a prime (e.g., payable) that is morphologically related and suffixed (Marslen-Wilson, Tyler, Waksler, & Older, 1994). To account for null facilitation (viz., the "suffix-suffix" effect), Marslen-Wilson and his colleagues posit inhibitory links between suffixes of morphological relatives. The present study assesses the generality of the "suffix-suffix" effect. When morphological facilitation is assessed relative to an orthographically related baseline, suffixed primes facilitate derivationally as well as inflectionally related morphological targets when primes are visual as well as auditory in both the lexical decision and naming tasks. The present findings call into question lexical models that posit inhibitory links between suffixes of morphological relatives.

Morphological units in the Arabic mental lexicon

Standard views of morphology in Modern Standard Arabic hold that surface word forms comprise at least two morphemes: a three-consonantal root conveying semantic meaning and a word pattern carrying syntactic information. An alternative account claims that semantic information is carried by a bi-consonantal morphological unit called the etymon. Accordingly, in the form [batara] the core meaning is carried not by the tri-consonantal root morpheme [btr] but by the etymon morpheme [b,t] which surfaces in other forms like [batta] "sever", [batala] "cut off" with the same meaning "cutting". Previous experimental research in Semitic languages has assumed the tri-consonantal root/word pattern approach. In cross-modal and masked priming experiments we ask whether the etymon, as a more fine-grained two-consonantal morphological unit, can yield the morphological priming effects typically obtained with tri-consonantal root morphemes. The results clearly show that two words sharing an etymon do facilitate each other both in cross-modal and masked priming even though they do not share a root, controlling for semantic and for form overlap effects. The bearing of these results on theories of morphological processing and representation is discussed.

Morphological facilitation following prefixed but not suffixed primes: lexical architecture or modality-specific processes?

Morphological facilitation was examined in immediate (Experiment 1) and long-term (Experiment 2) lexical decision with English materials. For the target (payment), related primes consisted of base-alone (pay), affix-plus-base (prepay), or base-plus-affix (payable) combinations, thereby defining position of overlap. In addition, modality of presentation varied for primes and targets (Experiment 1). At short lags, the advantage for prepay-payment over payable-payment type pairs was significant when primes were visual (V) and targets were auditory (A), marginal under AV conditions, and nonexistent under VV conditions. At long lags, the magnitude of VV did not vary with position of overlap. Morphological facilitation was stable across changes in modality following prefixed and simple forms, reflecting lexical architecture. By contrast, the absence of facilitation following suffixed primes presented cross-modally implicates modality-specific processing.