Transposed-letter similarity effects in naming pseudowords: Evidence from children and adults

Transposition and substitution-letter effects in a flanker task: Evidence from children and adults

Several studies have shown that parafoveal processing is essential in reading development. In this study, we explore the effect of transposing and substituting inner and outer letters in a flanker lexical decision task administered to 78 children and 65 adults. The results show a significant interaction between the Group factor and the Flanker factor, suggesting differences in the effects of flankers for children and adults. In the case of adults, transposed and substituted letters generated benefit of the same magnitude in comparison with the unrelated condition, but of lesser magnitude than the Identity condition. In the case of children, the results show facilitation for the transposed conditions of the same magnitude as the Identity condition. However, the substitution conditions failed to generate any benefit in comparison with the unrelated condition. The results for the adults are in line with the predictions of the open bigram model, whereas the results for the children are explained through a developmental perspective of the dual-route architecture and open bigram framework.

Eye Movement Measures of Within-Language and Cross-Language Activation During Reading in Monolingual and Bilingual Children and Adults: A Focus on Neighborhood Density Effects

We used eye movement measures of first-language (L1) and second-language (L2) paragraph reading to investigate how the activation of multiple lexical candidates, both within and across languages, influences visual word recognition in four different age and language groups: (1) monolingual children; (2) monolingual young adults; (3) bilingual children; and (4) bilingual young adults. More specifically, we focused on within-language and cross-language orthographic neighborhood density effects, while controlling for the potentially confounding effects of orthographic neighborhood frequency. We found facilitatory within-language orthographic neighborhood density effects (i.e., words were easier to process when they had many vs. few orthographic neighbors, evidenced by shorter fixation durations) across the L1 and L2, with larger effects in children vs. adults (especially the bilingual ones) during L1 reading. Similarly, we found facilitatory cross-language neighborhood density effects across the L1 and L2, with no modulatory influence of age or language group. Taken together, our findings suggest that word recognition benefits from the simultaneous activation of visually similar word forms during naturalistic reading, with some evidence of larger effects in children and particularly those whose words may have differentially lower baseline activation levels and/or weaker links between word-related information due to divided language exposure: bilinguals.

The influence of reading expertise in mirror-letter perception: Evidence from beginning and expert readers

The visual word recognition system recruits neuronal systems originally developed for object perception which are characterized by orientation insensitivity to mirror reversals. It has been proposed that during reading acquisition beginning readers have to "unlearn" this natural tolerance to mirror reversals in order to efficiently discriminate letters and words. Therefore, it is supposed that this unlearning process takes place in a gradual way and that reading expertise modulates mirror-letter discrimination. However, to date no supporting evidence for this has been obtained. We present data from an eye-movement study that investigated the degree of sensitivity to mirror-letters in a group of beginning readers and a group of expert readers. Participants had to decide which of the two strings presented on a screen corresponded to an auditorily presented word. Visual displays always included the correct target word and one distractor word. Results showed that those distractors that were the same as the target word except for the mirror lateralization of two internal letters attracted participants' attention more than distractors created by replacement of two internal letters. Interestingly, the time course of the effects was found to be different for the two groups, with beginning readers showing a greater tolerance (decreased sensitivity) to mirror-letters than expert readers. Implications of these findings are discussed within the framework of preceding evidence showing how reading expertise modulates letter identification.

Perceptual uncertainty is a property of the cognitive system

We qualify Frost's proposals regarding letter-position coding in visual word recognition and the universal model of reading. First, we show that perceptual uncertainty regarding letter position is not tied to European languages-instead it is a general property of the cognitive system. Second, we argue that a universal model of reading should incorporate a developmental view of the reading process.

On the flexibility of letter position coding during lexical processing: the case of Thai

In Indo-European languages, letter position coding is particularly noisy in middle positions (e.g., judge and jugde look very similar), but not in the initial letter position (e.g., judge vs. ujdge). Here we focus on a language (Thai) which, potentially, may be more flexible with respect to letter position coding than Indo-European languages: (i) Thai is an alphabetic language which is written without spaces between words (i.e., there is a degree of ambiguity in relation to which word a given letter belongs to) and (ii) some of the vowels are misaligned (e.g., [see text] ε:bn/ is pronounced as /bε:n/), whereas others are not (e.g., [see text]/a:p/ is pronounced as /a:p/). We conducted a masked priming lexical decision experiment with 3-4 letter Thai words (with vs. without an initial misaligned vowel) in which the prime was: (i) identical to the target, (ii) a nonword generated by transposing the two initial letters of the target, or (iii) a replacement-letter control nonword. Results showed a significant masked transposed-letter priming effect in the initial letter positions, which was similar in size for words with and without an initial misaligned vowel. These findings reflect that: (i) letter position coding in Thai is very flexible and (ii) the nature of the obtained priming effects is orthographic rather than phonological.

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.

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.

There is no clam with coats in the calm coast: Delimiting the transposed-letter priming effect

In this article, we explore the transposed-letter priming effect (e.g., jugde–JUDGE vs. jupte–JUDGE), a phenomenon that taps into some key issues on how the brain encodes letter positions and has favoured the creation of new input coding schemes. However, almost all the empirical evidence from transposed-letter priming experiments comes from nonword primes (e.g., jugde–JUDGE). Indeed, previous evidence when using word–word pairs (e.g., causal–CASUAL) is not conclusive. Here, we conducted five masked priming lexical decision experiments that examined the relationship between pairs of real words that differed only in the transposition of two of their letters (e.g., CASUAL vs. CAUSAL). Results showed that, unlike transposed-letter nonwords, transposed-letter words do not seem to affect the identification time of their transposed-letter mates. Thus, prime lexicality is a key factor that modulates the magnitude of transposed-letter priming effects. These results are interpreted under the assumption of the existence of lateral inhibition processes occurring within the lexical level—which cancels out any orthographic facilitation due to the overlapping letters. We examine the implications of these findings for models of visual-word recognition.

Does letter position coding depend on consonant/vowel status? Evidence with the masked priming technique

Recently, a number of input coding schemes (e.g., SOLAR model, SERIOL model, open-bigram model, overlap model) have been proposed that capture the transposed-letter priming effect (i.e., faster response times for jugde-JUDGE than for jupte-JUDGE). In their current version, these coding schemes do not assume any processing differences between vowels and consonants. However, in a lexical decision task, Perea and Lupker (2004, JML; Lupker, Perea, & Davis, 2008, L&CP) reported that transposed-letter priming effects occurred for consonant transpositions but not for vowel transpositions. This finding poses a challenge for these recently proposed coding schemes. Here, we report four masked priming experiments that examine whether this consonant/vowel dissociation in transposed-letter priming is task-specific. In Experiment 1, we used a lexical decision task and found a transposed-letter priming effect only for consonant transpositions. In Experiments 2-4, we employed a same-different task - a task which taps early perceptual processes - and found a robust transposed-letter priming effect that did not interact with consonant/vowel status. We examine the implications of these findings for the front-end of the models of visual word recognition.

Children like dense neighborhoods: Orthographic neighborhood density effects in novel readers

Previous evidence with English beginning readers suggests that some orthographic effects, such as the orthographic neighborhood density effects, could be stronger for children than for adults. Particularly, children respond more accurately to words with many orthographic neighbors than to words with few neighbors. The magnitude of the effects for children is much higher than for adults, and some researchers have proposed that these effects could be progressively modulated according to reading expertise. The present paper explores in depth how children from 1st to 6th grade perform a lexical decision with words that are from dense or sparse orthographic neighborhoods, attending not only to accuracy measures, but also to response latencies, through a computer-controlled task. Our results reveal that children (like adults) show clear neighborhood density effects, and that these effects do not seem to depend on reading expertise. Contrarily to previous claims, the present work shows that orthographic neighborhood effects are not progressively modulated by reading skill. Further, these data strongly support the idea of a general language-independent preference for using the lexical route instead of grapheme-to-phoneme conversions, even in beginning readers. The implications of these results for developmental models in reading and for models in visual word recognition and orthographic encoding are discussed.

Lexical competition is enhanced in the left hemisphere: evidence from different types of orthographic neighbors

Two divided visual field lexical decision experiments were conducted to examine the role of the cerebral hemispheres in orthographic neighborhood effects. In Experiment 1, we employed two types of words: words with many substitution neighbors (high-N) and words with few substitution neighbors (low-N). Results showed a facilitative effect of N in the left visual field (i.e., right hemisphere) and an inhibitory effect of N in the right visual field (left hemisphere). In Experiment 2, we examined whether the inhibitory effect of the higher frequency neighbors increases in the left hemisphere as compared to the right hemisphere. To go beyond the usual N-metrics, we selected words with (or without) higher frequency neighbors (addition, deletion, or transposition neighbors). Results showed that the inhibitory effect of neighborhood frequency is enhanced in the right visual field. We examine the implications of these findings for the orthographic coding schemes employed by the models of visual word recognition.

The effects of length and transposed-letter similarity in lexical decision: evidence with beginning, intermediate, and adult readers

Do length and transposed-letter effects reflect developmental changes on reading acquisition in a transparent orthography? Can computational models of visual word recognition accommodate these changes? To answer these questions, we carried out a masked priming lexical decision experiment with Spanish beginning, intermediate, and adult readers (N=36, 44, and 39; average age: 7, 11, and 22 years, respectively). Target words were either short or long (6.5 vs. 8.5 letters), and transposed-letter primes were formed by the transposition of two letters (e.g. aminal-ANIMAL) or by the substitution of two letters (orthographic control: arisal-ANIMAL). Children showed a robust length effect (i.e. long words were read slower than short words) that vanished in adults. In addition, both children and young adults showed a transposed-letter priming effect relative to the control condition. A robust transposed-letter priming effect was also observed in non-word reading, which strongly suggests that this effect occurs at an early prelexical level. Taken together, the results reveal that children evolve from a letter-by-letter reading to a direct lexical access and that the lexical decision task successfully captures the changing strategies used by beginning, intermediate, and adult readers. We examine the implications of these findings for the recent models of visual word recognition.