Elisabeth Beyersmann

Morphological processing during visual word recognition in developing readers: Evidence from masked priming

Masked priming studies with adult readers have provided evidence for a form-based morpho-orthographic segmentation mechanism that “blindly” decomposes any word with the appearance of morphological complexity. The present studies investigated whether evidence for structural morphological decomposition can be obtained with developing readers. We used a masked primed lexical decision design first adopted by Rastle, Davis, and New (2004), comparing truly suffixed (golden–GOLD) and pseudosuffixed (mother–MOTH) prime–target pairs with nonsuffixed controls (spinach–SPIN). Experiment 1 tested adult readers, showing that priming from both pseudo- and truly suffixed primes could be obtained using our own set of high-frequency word materials. Experiment 2 assessed a group of Year 3 and Year 5 children, but priming only occurred when prime and target shared a true morphological relationship, and not when the relationship was pseudomorphological. This pattern of results indicates that morpho-orthographic decomposition mechanisms do not become automatized until a relatively late stage in reading development.

Parallel processing of whole words and morphemes in visual word recognition

Models of morphological processing make different predictions about whether morphologically complex written words are initially decomposed and recognized on the basis of their morphemic subunits or whether they can directly be accessed as whole words and at what point semantics begin to influence morphological processing. In this study, we used unprimed and masked primed lexical decision to compare truly suffixed (darkest) and pseudosuffixed words (glossary) with within-boundary (d ra kest/g ol ssary) to across-boundary (dar ek st/glos as ry) letter transpositions. Significant transposed-letter similarity effects were found independently of the morphological position of the letter transposition, demonstrating that, in English, morphologically complex whole-word representations can be directly accessed at initial word processing stages. In a third masked primed lexical decision experiment, the same materials were used in the context of stem target priming, and it was found that truly suffixed primes facilitate the recognition of their stem-target (darkest–DARK) to the same extent as pseudosuffixed primes (glossary–GLOSS), which is consistent with theories of early morpho-orthographic decomposition. Taken together, our findings provide evidence for both whole-word access and morphological decomposition at initial stages of visual word recognition and are discussed in the context of a hybrid account.

Early morphological decomposition during visual word recognition: Evidence from masked transposed-letter priming

The present experiments were designed to explore the theory of early morpho-orthographic segmentation (Rastle, Davis, & New, Psychonomic Bulletin & Review 11,1090–1098, 2004), which postulates that written words with a true morphologically complex structure (cleaner) and those with a morphological pseudostructure (corner) are both decomposed into affix and stem morphemes. We used masked complex transposed-letter (TL) nonword primes in a lexical decision task. Experiment 1 replicated the well-known masked TL-priming effect using monomorphemic nonword primes (e.g., wran–WARN). Experiment 2 used the same nonword TL stems as in Experiment 1, but combined them with real suffixes (e.g., ish as in wranish–WARN). Priming was compared with that from nonsuffixed primes in which the real suffixes were replaced with nonmorphemic endings (e.g., el as in wranel–WARN). Significant priming was found in the suffixed but not in the nonsuffixed condition, suggesting that affix-stripping occurs at prelexical stages in visual word recognition and operates over early letter-position encoding mechanisms.

Early morphological decomposition of suffixed words : masked priming evidence with transposed-letter nonword primes

Many studies have previously reported that the recognition of a stem target (e.g., teach) is facilitated by the prior masked presentation of a prime consisting of a derived form of it (e.g., teacher). We conducted two lexical decision experiments to investigate masked morphological priming in Spanish. Experiment 1 showed that equal magnitudes of masked stem-target priming are obtained for both morphologically complex word primes (e.g., doloroso-DOLOR [painful-PAIN]) and morphologically complex nonword primes that included letter transpositions within the stem (e.g., dlooroso-DOLOR). Experiment 2 used morphologically complex nonword primes comprising lexically illegal combinations of stems and suffixes (e.g., total + ito [a little total]). Priming was obtained for morphologically related nonword primes (e.g., totalito-TOTAL), but not for nonword primes that included letter transpositions within the pseudostem (e.g., ttoalito-TOTAL). Our data suggest that morphoorthographic parsing mechanisms benefit from semantic constraints at early stages in the reading system, which we discuss in the context of current morphological processing accounts.

Morpho-orthographic segmentation without semantics

Masked priming studies have repeatedly provided evidence for a form-based morpho-orthographic segmentation mechanism that blindly decomposes any word with the mere appearance of morphological complexity (e.g., corn + er). This account has been called into question by Baayen et al. Psychological Review, 118, 438–482 (2011), who pointed out that the prime words previously tested in the morpho-orthographic condition vary in the extent to which the suffix conveys regular meaning. In the present study, we investigated whether evidence for morpho-orthographic segmentation can be obtained with a set of tightly controlled prime words that are entirely semantically opaque. Using a visual lexical decision task, we compared priming from truly suffixed primes (hunter-HUNT), completely opaque pseudo-suffixed primes (corner-CORN), and non-suffixed primes (cashew-CASH). The results show comparable magnitudes of priming for the truly suffixed and pseudo-suffixed primes, and no priming from non-suffixed primes, and therefore provide further important evidence in support of morpho-orthographic segmentation processes operating in the absence of any possible role for semantics.

Semantic processing during morphological priming: An ERP study

Previous research has yielded conflicting results regarding the onset of semantic processing during morphological priming. The present study was designed to further explore the time-course of morphological processing using event-related potentials (ERPs). We conducted a primed lexical decision study comparing a morphological (LAVAGE - laver [washing - wash]), a semantic (LINGE - laver [laundry - wash]), an orthographic (LAVANDE - laver [lavender - wash]), and an unrelated control condition (HOSPICE - laver [nursing home - wash]), using the same targets across the four priming conditions. The behavioral data showed significant effects of morphological and semantic priming, with the magnitude of morphological priming being significantly larger than the magnitude of semantic priming. The ERP data revealed significant morphological but no semantic priming at 100-250 ms. Furthermore, a reduction of the N400 amplitude in the morphological condition compared to the semantic and orthographic condition demonstrates that the morphological priming effect was not entirely due to the semantic or orthographic overlap between the prime and the target. The present data reflect an early process of semantically blind morphological decomposition, and a later process of morpho-semantic decomposition, which we discuss in the context of recent morphological processing theories.

A developmental investigation of the first-letter advantage

Skilled adult readers identify the first letter in a string of random consonants better than letters at any other position, and this advantage for the initial position is not seen with strings of symbols or familiar shapes. Here we examined the developmental trajectory of this first-letter advantage by testing children in Grades 1 to 5 of primary education in a target-in-string identification paradigm. Strings of five letters or five simple shapes were briefly presented, and children were asked to identify a target letter/shape at one of the five possible positions. Children responded by choosing between the target and an alternative that was a neighboring letter/shape (e.g., TPFMR-M vs. F at position 4). The serial position function linking accuracy to position-in-string was found to be affected by reading ability differently for letter stimuli compared with shape stimuli, and this was found to be almost entirely driven by differences in performance in identifying targets at the first position in strings. Here, accuracy increased more rapidly for letter stimuli than for shape stimuli as reading ability increased. This developmental pattern, plus the fact that letter strings were composed of random consonants and the task minimized the involvement of verbal recoding, allows us to exclude an explanation of the first-letter advantage in terms of serial reading strategies or phonological decoding. The findings suggest that the first-letter advantage is a function of, and a marker for, increasingly efficient orthographic processing.

Effects of reading proficiency on embedded stem priming in primary school children

Prior evidence from masked morphological priming has revealed conflicting findings regarding the acquisition of morpho-orthographic segmentation mechanisms in developing readers. Here, we examined changes in masked morphological priming across grade within a large sample of French primary school children (n = 191, Grades 2-5) and how these effects are modulated by individual differences in reading proficiency, spelling proficiency, and morphological awareness. Target words were preceded by either (a) a suffixed word prime (e.g., tristesse-TRISTE), (b) a suffixed nonword prime (e.g., tristerie-TRISTE), (c) a non-suffixed nonword prime (e.g., tristald-TRISTE), or (d) an unrelated prime (e.g., direction-TRISTE) using very short prime durations (50 ms). Moreover, a frequency manipulation was included for suffixes and non-suffixes. The results revealed robust suffixed word priming across all children independent of grade and proficiency. On the other hand, priming in the suffixed and non-suffixed nonword conditions was modulated by reading proficiency, with high-proficiency children showing facilitation and low-proficiency children showing inhibition. The effects of suffix and non-suffix frequency were modulated by grade, with decreasing effects as grade increased. None of the observed priming effects were modulated by grade, spelling proficiency, or morphological awareness. The results suggest that reading proficiency is an important predictor for embedded stem activation mechanisms in primary school children, which we discuss in the context of recent theories of morphological processing.

The Influence of plural dominance in aphasic word production

Background: Plural dominance refers to the relative difference between the frequencies of a word in its singular and plural forms. Most of the evidence for theoretical accounts of plural dominance has come from psycholinguistic perception experiments (e.g., Baayen, Burani, & Schreuder, 1996; Baayen, Dijkstra, & Schreuder, 1997; Baayen, Schreuder, & Sproat, 1998). Only a few studies have investigated the production side of dominance, even in unimpaired speakers (e.g., Baayen, Levelt, Schreuder, & Ernestus, 2008). To our knowledge there is only one published neuropsychological study from Luzzatti, Mondini, and Semenza (2001) that uses reading-aloud data from an Italian brain-impaired speaker. Although findings across paradigms are inconsistent, they do indicate that plural-dominant nouns behave differently from singular-dominant nouns, and therefore suggest a difference in representation. Aims: This paper investigates processing of plural nouns in aphasia with a specific focus on effects of dominance. Methods & Procedures: We carried out two single-case studies with two women with aphasia, FME and DRS, who showed word retrieval deficits in picture naming as a result of different underlying functional impairments. The main task of interest was picture naming of single and multiple objects in order to test effects of plural dominance. In addition, word–picture matching tested number representation in comprehension. Outcome & Results: DRS showed a specific morphological impairment with plural marking, whereas FME had no specific morphological deficit. The results are discussed in the framework of current psycholinguistic accounts on the representation and processing of plural nouns (e.g., Levelt, Roelofs, & Meyer, 1999; Schreuder & Baayen, 1995). Conclusions: Different effects of plural dominance shown by both women with aphasia result from different underlying functional deficits, which indicate differences in the representation of plural dominance across processing levels.

Does plural dominance play a role in spoken picture naming? A comparison of unimpaired and impaired speakers

Abstract This study investigates the effect of frequency on plural processing. In particular it explores the effect of relative frequency differences between plurals and their singular forms on the representation of plurals. This paper reports data from a group of thirty-eight unimpaired speakers and compares their spoken picture naming of single and multiple objects to that of two people with acquired language impairments (aphasia). For both participant groups (unimpaired and impaired), we observed two key findings for picture naming: first, plurals that are lower in frequency than their singulars (singular-dominant plurals) are responded to more slowly or with more errors compared to their singulars. Second, for plurals that are higher in frequency than their singulars (plural-dominant plurals), no difference in reaction time or error rate was detected between singulars and plurals. By capitalising on patterns observed in both unimpaired and impaired language processing, this study suggests that plural-dominant plurals are stored differently from singular-dominant plurals.