Is morpho-orthographic decomposition purely orthographic? Evidence from masked priming in the same–different task

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.

EXPRESS: Are there Task-specific Effects in Morphological Processing? Examining Semantic Transparency Effects in Semantic Categorization and Lexical Decision

Current theories of morphological processing include form-then-meaning accounts, form-with-meaning accounts, and connectionist theories. Form-then meaning accounts argue that the morphological decomposition of complex words is based purely on orthographic structure, while form-with meaning accounts argue that decomposition is influenced by the semantic properties of the stem. Connectionist theories, on the other hand, argue that morphemes are encoded as statistical patterns of occurrences between form and meaning. The weight of evidence from the literature thus far suggests that morphological decomposition is best explained by form-then-meaning accounts. That said, conflicting empirical findings exist, and more importantly, semantic transparency effects in morphological processing have been examined almost exclusively with the lexical decision task, in which participants discriminate between words and nonwords. Consequently, the extent to which observed results reflect the specific demands of the lexical decision task remains unclear. The present study extends previous work by testing if the processing dynamics of early morphological processing are moderated by task requirements. Using the masked morphological priming paradigm, this hypothesis was tested by examining semantic transparency effects for a common set of words across semantic categorization and lexical decision. In both tasks, priming was stronger for transparent (e.g., painter-PAINT) than opaque (e.g., corner-CORN) prime-target pairs; these results speak against form-then-meaning accounts. These findings further inform theories of morphological processing and underscore the importance of examining the interplay between task-general and task-specific mechanisms.

Morpho-orthographic segmentation of opaque and transparent derived words: New evidence for Spanish

Semantic transparency has been extensively analysed in research on visual word recognition. Under the masked priming paradigm, it has consistently been shown that opaque and transparent words are facilitated relative to form-related controls, but differences in priming between one condition and another have not been conclusively proven. Hence, research has been unable to theoretically elucidate the possible value of semantic transparency in the processing of derived words. This study describes two lexical decision experiments in Spanish. Experiment 1 revealed differences between the transparent and orthographic conditions, with no differences between the other conditions in the analyses of the error rates. In the second experiment, the participants visited the laboratory on two occasions, separated by a week. The task was administered twice, with participants responding to one of the experimental lists on each day. The results of this second experiment revealed significant differences in the size of the priming effect of the opaque and transparent conditions compared with the form-related condition, but without differences between these two effects. We discuss these findings from the perspective of current models of visual lexical processing.

Phonological priming effects with same-script primes and targets in the masked priming same-different task

Norris, Kinoshita and colleagues (Kinoshita & Norris, Journal of Experimental Psychology: Learning, Memory, and Cognition, 35(1), 1-18, 2009; Journal of Experimental Psychology: General, 137(3), 434-455, 2010; Norris & Kinoshita, Quarterly Journal of Experimental Psychology, 63(1), 194-204, 2008) have suggested that the masked priming same-different task (SDT) is an excellent tool for studying the orthographic coding process because, in most circumstances, performance in that task is driven entirely by orthographic codes. More specifically, although evidence of phonological influences (i.e., phonological priming effects in the SDT) have been reported, Kinoshita, Gayed, and Norris (Journal of Experimental Psychology: Human Perception and Performance, 44(11), 1661-1671, 2018) have claimed that phonological priming does not arise in the SDT when the prime and target are written in the same script and the targets are words, the most typical experimental situation. Indeed, it does appear that no-one has yet reported phonological priming effects in such situations. The question of whether it is possible to observe phonological priming in such situations was more fully examined in the present experiments. Experiment 1 involved a masked priming SDT using Japanese Kanji script in which the primes and targets were homophonic but shared no characters. Experiment 2 was a parallel experiment using Chinese stimuli. In both experiments, phonological priming effects were observed for both one- and two-character words. These experiments indicate that, although the priming effects in masked priming SDTs undoubtedly have a strong orthographic basis, phonological codes also play a role even when the prime and (word) target are written in the same script.

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.

What Cross-morphemic Letter Transposition in Derived Nonwords Tells us about Lexical Processing

According to an obligatory decomposition account of polymorphemic word recognition, a nonword that is composed of a real word plus derivational affix (e.g., teachen) should prime its stem (TEACH) to the same extent that a truly suffixed word does (e.g., teacher). The stem will be activated in both cases after the suffix is removed prior to the lexical status of the letter-string being of relevance. Importantly, disruption to the stem and suffix through letter transposition should have the same impact on the nonwords and words, with teacehn and teacehr equally priming TEACH. However, an experiment by Diependaele, Morris, Serota, Bertrand, and Grainger (2013) found that the equivalent priming for nonwords and words only occurred when they were intact. When letters were transposed, only the truly derived words showed priming. Since such a result cannot be handled by an obligatory decomposition account, it is important to replicate it. Therefore, the present study repeated the conditions of Diependaele et al. (2013), along with a nonword condition where the stem was followed by a non-suffix (e.g., teachin or teacihn). It was found that priming was maintained across all conditions regardless of letter transposition, hence maintaining obligatory decomposition as a viable account. However, the findings with the non-suffixed nonwords led to the conclusion that morphological structure does not control decomposition, but rather, has its impact after form-based components of the letter-string have been activated.

A backwards glance at words: Using reversed-interior masked primes to test models of visual word identification

The experiments reported here used “Reversed-Interior” (RI) primes (e.g., cetupmor-COMPUTER) in three different masked priming paradigms in order to test between different models of orthographic coding/visual word recognition. The results of Experiment 1, using a standard masked priming methodology, showed no evidence of priming from RI primes, in contrast to the predictions of the Bayesian Reader and LTRS models. By contrast, Experiment 2, using a sandwich priming methodology, showed significant priming from RI primes, in contrast to the predictions of open bigram models, which predict that there should be no orthographic similarity between these primes and their targets. Similar results were obtained in Experiment 3, using a masked prime same-different task. The results of all three experiments are most consistent with the predictions derived from simulations of the Spatial-coding model.

Discrimination in lexical decision

In this study we present a novel set of discrimination-based indicators of language processing derived from Naive Discriminative Learning (ndl) theory. We compare the effectiveness of these new measures with classical lexical-distributional measures-in particular, frequency counts and form similarity measures-to predict lexical decision latencies when a complete morphological segmentation of masked primes is or is not possible. Data derive from a re-analysis of a large subset of decision latencies from the English Lexicon Project, as well as from the results of two new masked priming studies. Results demonstrate the superiority of discrimination-based predictors over lexical-distributional predictors alone, across both the simple and primed lexical decision tasks. Comparable priming after masked corner and cornea type primes, across two experiments, fails to support early obligatory segmentation into morphemes as predicted by the morpho-orthographic account of reading. Results fit well with ndl theory, which, in conformity with Word and Paradigm theory, rejects the morpheme as a relevant unit of analysis. Furthermore, results indicate that readers with greater spelling proficiency and larger vocabularies make better use of orthographic priors and handle lexical competition more efficiently.

Transposed-Letter Priming Across Inflectional Morpheme Boundaries

This study reports findings from two experiments testing whether a transposed-letter (TL) priming effect can be obtained when the transposition occurs across morphological boundaries. Previous studies have primarily tested derivationally complex words or compound words, but have not examined a more rule-based and productive morphological structure, i.e., inflectionally complex words, using masked priming. Experiment 1 tested TL priming with nonword primes and inflected targets (FOCUSING). Nonword primes were formed by transposing letters either within the root morpheme (fcousing) or across two morphemes (focuisng). Experiment 2 used the same nonword primes, but had the root words as targets (FOCUS). Both experiments showed similar TL priming effects for within-morpheme and across-boundary positions, indicating that morphological decomposition takes place only after letter positions in a word have been assigned. This finding provides additional evidence to previous research testing derived and compound words showing TL priming regardless of the position of transposition.

Does Top-Down Feedback Modulate the Encoding of Orthographic Representations During Visual-Word Recognition?

In masked priming lexical decision experiments, there is a matched-case identity advantage for nonwords, but not for words (e.g., ERTAR-ERTAR <  ertar-ERTAR; ALTAR-ALTAR = altar-ALTAR). This dissociation has been interpreted in terms of feedback from higher levels of processing during orthographic encoding. Here, we examined whether a matched-case identity advantage also occurs for words when top-down feedback is minimized. We employed a task that taps prelexical orthographic processes: the masked prime same-different task. For "same" trials, results showed faster response times for targets when preceded by a briefly presented matched-case identity prime than when preceded by a mismatched-case identity prime. Importantly, this advantage was similar in magnitude for nonwords and words. This finding constrains the interplay of bottom-up versus top-down mechanisms in models of visual-word identification.

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.

Differential Sensitivity of Letters, Numbers, and Symbols to Character Transpositions

This study was designed to explore whether the human visual system has different degrees of tolerance to character position changes for letter strings, digit strings, and symbol strings. An explicit perceptual matching task was used (same–different judgment), and participants' electrophysiological activity was recorded. Materials included trials in which the referent stimulus and the target stimulus were identical or differed either by two character replacements or by transposing two characters. Behavioral results showed clear differences in the magnitude of the transposed-character effect for letters as compared with digit and symbol strings. Electrophysiological data confirmed this observation, showing an N2 character transposition effect that was only present for letter strings. An earlier N1 transposition effect was also found for letters but was absent for symbols and digits, whereas a later P3 effect was found for all types of string. These results provide evidence for a position coding mechanism that is specific to letter strings, that was most prominent in an epoch between 200 and 325 msec, and that operates in addition to more general-purpose position coding mechanisms.

Transposed-letter priming effect in Hebrew in the same-different task

We investigated the interaction between morphological structure and transposed-letter priming using the same-different task with Hebrew, a Semitic language in which morphology has been shown to play a key role in visual word recognition. In contrast to the results observed with lexical decision (e.g., Velan & Frost, 2009, 2011), a transposed-letter priming effect was observed irrespective of the morphological structure of the words. We take these results to suggest that morphological decomposition occurs only in the service of lexical access. We discuss further a unique feature of written Arabic, another Semitic language, to explain the apparent conflict between our findings and those reported by Perea, Abu Mallouh, García-Orza, and Carreiras (2010).

Facilitation versus Inhibition in the Masked Priming Same–Different Matching Task

In the past years, growing attention has been devoted to the masked priming same–different task introduced by Norris and Kinoshita (2008, Journal of Experimental Psychology: General). However, a number of researchers have raised concerns on the nature of the cognitive processes underlying this task—in particular the suspicion that masked priming effects in this task are mostly inhibitory in nature and may be affected by probe–prime contingency. To examine the pattern of facilitative/inhibitory priming effects in this task, we conducted two experiments with an incremental priming paradigm using four stimulus–onset asynchronies (13, 27, 40, and 53 ms). Experiment 1 was conducted under a predictive-contingency scenario (probe–prime–target; i.e., “same” trials: HOUSE– house– HOUSE vs. house– water– HOUSE; “different” trials: field– house– HOUSE vs. field– water– HOUSE), while Experiment 2 employed a zero-contingency scenario (i.e., “same” trials: HOUSE– house– HOUSE vs. house– water– HOUSE; “different” trials: field– field– HOUSE vs. field– water– HOUSE). Results revealed that, for “same” responses, both facilitation and inhibition increased linearly with prime duration in the two scenarios, whereas the pattern of data varied for “different” responses, as predicted by the Bayesian Reader model.

Masked priming effects are modulated by expertise in the script

In a recent study using a masked priming same-different matching task, Garcı´a-Orza, Perea, and Munoz (2010) found a transposition priming effect for letter strings, digit strings, and symbol strings, but not for strings of pseudoletters (i.e., EPRI-ERPI produced similar response times to the control pair EDBI-ERPI). They argued that the mechanism responsible for position coding in masked priming is not operative with those "objects" whose identity cannot be attained rapidly. To assess this hypothesis, Experiment 1 examined masked priming effects in Arabic for native speakers of Arabic, whereas participants in Experiments 2 and 3 were lower intermediate learners of Arabic and readers with no knowledge of Arabic, respectively. Results showed a masked priming effect only for readers who are familiar with the Arabic script. Furthermore, transposed-letter priming in native speakers of Arabic only occurred when the order of the root letters was kept intact. In Experiments 3-7, we examined why masked repetition priming is absent for readers who are unfamiliar with the Arabic script. We discuss the implications of these findings for models of visual-word recognition.