Transposed-letter Effects Research Articles

A stringent test of visuospatial position uncertainty accounts of letter position coding

ABSTRACT The encoding of letter position appears to be relatively flexible. Transposed-letter pseudowords (e.g. CHOLOCATE) are more often misidentified as their base words (CHOCOLATE) compared to replacement-letter pseudowords (CHOTONATE) – transposed-letter effect. One plausible explanation for this effect is that it arises from visuospatial position uncertainty in letter position encoding. To test this account, we conducted two lexical decision experiments. Pseudowords were presented syllable-by-syllable in vertical and zigzag formats, making the position of the critical transposed or replaced letters more noticeable. In Experiment 1, we found a transposed-letter effect in both formats, which was sizeable in the error rates. Experiment 2 introduced a delayed 900-ms response cue to assess whether the transposed-letter effect fully vanishes in the absence of immediate time pressure. Results again showed a transposed-letter effect. Thus, while visuospatial uncertainty contributes to letter position flexibility during word recognition, an additional non-visual component is necessary to fully explain this phenomenon.

Individual differences and the transposed letter effect during reading.

When a preview contains substituted letters (SL; markey) word identification is more disrupted for a target word (monkey), compared to when the preview contains transposed letters (TL; mnokey). The transposed letter effect demonstrates that letter positions are encoded more flexibly than letter identities, and is a robust finding in adults. However, letter position encoding has been shown to gradually become more flexible as reading skills develop. It is unclear whether letter position encoding flexibility reaches maturation in skilled adult readers, or whether some differences in the magnitude of the TL effect remain in relation to individual differences in cognitive skills. We examined 100 skilled adult readers who read sentences containing a correct, TL or SL preview. Previews were replaced by the correct target word when the reader's gaze triggered an invisible boundary. Cognitive skills were assessed and grouped based on overlapping variance via Principal Components Analysis (PCA) and subsequently used to predict eye movement measures for each condition. Consistent with previous literature, adult readers were found to generally encode letter position more flexibly than letter identity. Very few differences were found in the magnitude of TL effects between adults based on individual differences in cognitive skills. The flexibility of letter position encoding appears to reach maturation (or near maturation) in skilled adult readers.

Reading about a RELO-VUTION.

Pseudowords created by transposing two letters of words (e.g., MOHTER; CHOLOCATE) are highly confusable with their base word; this is known as the transposed-letter similarity effect. In this work, we examined whether transposed-letter effects occur when words span more than one line (e.g., CHOLO- in one line and CATE in another line; note that the transposed letters L and C are in different lines). While this type of presentation is not the canonical format for reading in alphabetic languages, it is widely used in advertising, billboards, and street signs. Transposed-letter pseudowords and their replacement-letter controls were written in the standard one-line format versus a two-line format (Experiments 1-2) or a syllable-per-line format (Experiment 3). While results showed some decrease in the transposed-letter effect in the two-line and syllabic formats, the transposed-letter effect was still substantial in the accuracy of responses. These findings demonstrate that even when the letters being transposed are relatively far apart in space, the transposed-letter effect is still robust. Thus, a major component of letter position coding occurs at an abstract level.

Parafoveal processing and transposed-letter effects in dyslexic reading.

During parafoveal processing, skilled readers encode letter identity independently of letter position (Johnson et al., 2007). In the current experiment, we examined orthographic parafoveal processing in readers with dyslexia. Specifically, the eye movements of skilled readers and adult readers with dyslexia were recorded during a boundary paradigm experiment (Rayner, 1975). Parafoveal previews were either identical to the target word (e.g., nearly), a transposed‐letter preview (e.g., enarly), or a substituted‐letter preview (e.g., acarly). Dyslexic and non‐dyslexic readers demonstrated orthographic parafoveal preview benefits during silent sentence reading and both reading groups encoded letter identity and letter position information parafoveally. However, dyslexic adults showed, that very early in lexical processing, during parafoveal preview, the positional information of a word's initial letters were encoded less flexibly compared to during skilled adult reading. We suggest that dyslexic readers are less able to benefit from correct letter identity information (i.e., in the letter transposition previews) due to the lack of direct mapping of orthography to phonology. The current findings demonstrate that dyslexic readers show consistent and dyslexic‐specific reading difficulties in foveal and parafoveal processing during silent sentence reading.

Raeding with the fingres: Towards a universal model of letter position coding

Letter position coding in word recognition has been widely investigated in the visual modality (e.g., labotarory is confusable with laboratory), but not as much in the tactile modality using braille, leading to an incomplete understanding of whether this process is modality-dependent. Unlike sighted readers, braille readers do not show a transposed-letter similarity effect with nonadjacent transpositions (e.g., labotarory = labodanory; Perea et al., 2012). While this latter finding was taken to suggest that the flexibility in letter position coding was due to visual factors (e.g., perceptual uncertainty in the location of visual objects (letters)), it is necessary to test whether transposed-letter effects occur with adjacent letters to reach firm conclusions. Indeed, in the auditory modality (i.e., another serial modality), a transposed-phoneme effect occurs for adjacent but not for nonadjacent transpositions. In a lexical decision task, we examined whether pseudowords created by transposing two adjacent letters of a word (e.g., laboartory) are more confusable with their base word (laboratory) than pseudowords created by replacing those letters (laboestory) in braille. Results showed that transposed-letter pseudowords produced more errors and slower responses than the orthographic controls. Thus, these findings suggest that the mechanism of serial order, while universal, can be shaped by the sensory modality at play.

한글 철자 교환 효과의 부재: 글 읽기 시 안구운동으로부터의 증거

This study was aimed to further investigate whether the transposed letter effect can emerge in Korean sentence reading while participants’ eye movements were recorded. In Experiment 1, the boundary technique was employed to see if the letter transposition effect appears. Although the results showed the preview benefit, the letter transposition effect did not emerge. In Experiment 2, a lexical decision task was used to replicate the result reported in Experiment 1. As in Experiment 1, the absence of the letter transposition effect was observed in Experiment 2. The results observed here were discussed with respect to the previous findings and theoretical explanations.

Which Factors Modulate Letter Position Coding in Pre-literate Children?

One of the central landmarks of learning to read is the emergence of orthographic processing (i.e., the encoding of letter identity and letter order): it constitutes the necessary link between the low-level stages of visual processing and the higher-level processing of words. Regarding the processing of letter position, many experiments have shown worse performance in various tasks for the transposed-letter pair judge-JUDGE than for the orthographic control jupte-JUDGE. Importantly, 4-y.o. pre-literate children also show letter transposition effects in a same-different task: TZ-ZT is more error-prone than TZ-PH. Here, we examined whether this effect with pre-literate children is related to the cognitive and linguistic skills required to learn to read. Specifically, we examined the relation of the transposed-letter in a same-different task with the scores of these children in phonological, alphabetic and metalinguistic awareness, linguistic skills, and basic cognitive processes. To that end, we used a standardized battery to assess the abilities related with early reading acquisition. Results showed that the size of the transposed-letter effect in pre-literate children was strongly associated with the sub-test on basic cognitive processes (i.e., memory and perception) but not with the other sub-tests. Importantly, identifying children who may need a pre-literacy intervention is crucial to minimize eventual reading difficulties. We discuss how this marker can be used as a tool to anticipate reading difficulties in beginning readers.

Single Word Reading in the Real World: Effects of Transposed-Letters.

We investigated single word reading in a context where isolated word presentation is not unusual reading road signs in a simulated car driving situation. Participants had to indicate if the inscription on the road sign was a real word or not (lexical decision). The critical nonwords were created in two ways: by transposing two letters in a real word (e.g., the word Highway becomes Hihgway) or by substituting the same two letters with different letters (Hifpway). The baseword used to create the critical nonword stimuli were either congruent with a driving context (e.g., highway) or incongruent (e.g., garden). Nonwords created by a letter transposition were harder to reject as such compared with letter substitution nonwords a transposed-letter effect. The effect of baseword congruency was not significant and did not interact with the transposed-letter effect.

Are better young readers more likely to confuse their mother with their mohter?

One of the most replicated effects in the contemporary word recognition literature is the transposed-letter effect (TL effect): pseudowords created by the transposition of two letters (e.g., MOHTER) are often misread as the real word. This effect ruled out those accounts that assume that letter position is encoded accurately and led to more flexible coding schemes. Here, we examined whether reading skill modulates this effect. The relationship between reading skill and the TL effect magnitude is a contentious issue both empirically and theoretically. The present lexical decision experiment was designed to shed some light on the relationship between reading skill and the TL effect magnitude with a large sample of Grade 6 children. To that end, we conducted both multiple regression and path analyses. Results showed that a specific aspect of reading skills (pseudoword reading) negatively correlates with the TL effect's magnitude in the error data (i.e., MOHTER is less wordlike for better readers). This finding highlights the need for a comprehensive visual-word recognition model that includes individual variability and the multidimensional character of reading in school-age children.

Does orthographic processing emerge rapidly after learning a new script?

Orthographic processing is characterized by location-invariant and location-specific processing (Grainger, 2018): (1) strings of letters are more vulnerable to transposition effects than the strings of symbols in same-different tasks (location-invariant processing); and (2) strings of letters, but not strings of symbols, show an initial position advantage in target-in-string identification tasks (location-specific processing). To examine the emergence of these two markers of orthographic processing, we conducted a same-different task and a target-in-string identification task with two unfamiliar scripts (pre-training experiments). Across six training sessions, participants learned to fluently read and write one of these scripts. The post-training experiments were parallel to the pre-training experiments. Results showed that the magnitude of the transposed-letter effect in the same-different task and the serial function in the target-in-string identification tasks were remarkably similar for the trained and untrained scripts. Thus, location-invariant and location-specific processing does not emerge rapidly after learning a new script; instead, they may require thorough experience with specific orthographic structures.

A reexamination of consonant-vowel differences in masked transposed letter priming effects in the lexical decision task.

Most orthographic coding models are based on the assumption that the orthographic code does not distinguish between vowels and consonants and, therefore, those models predict no difference between vowel (cisano-CASINO) and consonant (caniso-CASINO) transposed-letter (TL) effects. The available data, however, do provide some evidence for a consonant-vowel distinction at the level of the orthographic code. Most centrally, masked priming lexical decision tasks, mainly carried out in Spanish, have shown priming from consonant TL primes (e.g., caniso) but not from vowel TL primes (e.g., cisano). The present experiments were an investigation of this pattern. Experiment 1, based on Schubert, Kinoshita, and Norris' (2018) stimuli which showed no consonant-vowel differences in an unprimed same-different task, also showed no consonant-vowel differences in masked TL priming effects in lexical decision showing, for the first time, a vowel TL priming effect in that task. Experiment 2, using Lupker, Perea, and Davis' (2008) Experiment 1a stimuli, also showed a small but significant vowel TL priming effect (a nonreplication of that experiment), while replicating the consonant TL priming effect that those authors originally reported. In Experiment 3, TL priming was again essentially unaffected by the consonant-vowel status of the letters involved as well as by target frequency, a variable on which the Experiment 1 and 2 stimuli differed. These results, supported by evoked response potential (ERP) results from other labs, suggest that consonant-vowel TL differences, when they do emerge in English, are likely are not due to the nature of the orthographic code. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The development on transposed-letter effect in English word recognition: Evidence from Late unbalanced Chinese-English bilinguals

The present study examined the orthographic processing of English visual word recognition in adult Chinese-speaking English learners under the framework of the multiple-route model of reading development. Two groups of adult learners with high and low English proficiency finished a forward-masked lexical decision task. The results showed a complicated scenario on transposed-letter effects, implying that the late unbalanced Chinese-English bilinguals with low English proficiency still needed to adopt a letter-to-letter reading strategy, and that the L2 users with high English proficiency also had not properly developed the fine-grained orthographic route even they had a long experience of English learning in the foreign language learning settings in China. Overall, it is suggested that late unbalanced Chinese-English bilinguals generally follow a path similar to that of native readers in acquiring English visual word recognition skills developed from the letter-to-letter reading strategy to the parallel orthographic processing strategies. However, since L2 users usually have no or limited spoken vocabulary of English before accessing printed words and inadequate supervision in developing L2 word reading skills, their development would be much slower than that of English native speakers.

Shaping the precision of letter position coding by varying properties of a writing system

ABSTRACTThere is substantial debate around the nature of letter position coding in reading. Research on a variety of Indo-European languages suggests uncertainty in position coding; for example, readers perceive transposed-letter stimuli (jugde) as similar to their base words (judge). However, these effects are not apparent for all languages. We developed a powerful new method to delineate how specific properties of a writing system shape the representation of letter position. Two groups of 24 adults learned to read novel words printed in artificial scripts. One group learned a dense orthography (i.e. with many anagrams) and one group learned a sparse orthography (i.e. no anagrams). Following four days of training, participants showed a larger transposed-letter effect in the sparse orthography than in the dense orthography. These results challenge existing models of orthographic processing in reading, and support the claim that orthographic representations are shaped by the nature of the writing system.

Phonological and orthographic coding in deaf skilled readers

Written language is very important in daily life. However, most deaf people do not achieve good reading levels compared to their hearing peers. Previous research has mainly focused on their difficulties when reading in a language with an opaque orthography such as English. In the present study, we investigated visual word recognition of deaf adult skilled readers while reading in Spanish, a language with a transparent orthography, for which obligatory phonological mediation has been claimed. Experiment 1 showed a pseudohomophone inhibitory effect in hearing but not in deaf people. Experiment 2 showed similar orthographic sensitivity, as measured by the transposed-letter effect, for both groups. These results suggest that deaf skilled readers do not rely on phonological mediation, while maintaining the same level of orthographic sensitivity as hearing readers, thus suggesting that the use of phonological coding is not required to access the lexicon and meaning in a language with a transparent orthography.

The importance of situation-specific encodings: analysis of a simple connectionist model of letter transposition effects

ABSTRACTThis paper analyses a three-layer connectionist network that solves a translation-invariance problem, offering a novel explanation for transposed letter effects in word reading. Analysis of the hidden unit encodings provides insight into two central issues in cognitive science: (1) What is the novelty of claims of “modality-specific” encodings? and (2) How can a learning system establish a complex internal structure needed to solve a problem? Although these topics (embodied cognition and learnability) are often treated separately, we find a close relationship between them: modality-specific features help the network discover an abstract encoding by causing it to break the initial symmetries of the hidden units in an effective way. While this neural model is extremely simple compared to the human brain, our results suggest that neural networks need not be black boxes and that carefully examining their encoding behaviours may reveal how they differ from classical ideas about the mind-world relationship.

Adaptive specialization in position encoding while learning to read.

The present experiments focused on how orthographic processing develops during reading acquisition. Specifically, a large, cross-sectional sample of children from grade 2 to grade 4 was exposed to pairs of words, pseudowords, digit strings, and pseudo-letter (Armenian) strings while their sensitivity to transpositions (T) and substitutions (S) of internal characters was investigated in a perceptual matching task. The results showed that the development of identity and position decoding diverged between the four stimulus categories. Most importantly, sensitivity improved with longer exposure to formal education and higher reading level to both S and T pairs for digit strings, but only to S pairs for words and pseudowords. The results were successfully reproduced in two small independent samples. We propose a general framework, the Adaptive Specialization Hypothesis, to accommodate the results. According to this hypothesis, the transposed-letter effect is not a hard-wired feature of the orthographic processing system but an adaptive response of the developing orthographic system to the constraints of lexical access in several orthographies.

Orthographic Reading Deficits in Dyslexic Japanese Children: Examining the Transposed-Letter Effect in the Color-Word Stroop Paradigm.

In orthographic reading, the transposed-letter effect (TLE) is the perception of a transposed-letter position word such as “cholocate” as the correct word “chocolate.” Although previous studies on dyslexic children using alphabetic languages have reported such orthographic reading deficits, the extent of orthographic reading impairment in dyslexic Japanese children has remained unknown. This study examined the TLE in dyslexic Japanese children using the color-word Stroop paradigm comprising congruent and incongruent Japanese hiragana words with correct and transposed-letter positions. We found that typically developed children exhibited Stroop effects in Japanese hiragana words with both correct and transposed-letter positions, thus indicating the presence of TLE. In contrast, dyslexic children indicated Stroop effects in correct letter positions in Japanese words but not in transposed, which indicated an absence of the TLE. These results suggest that dyslexic Japanese children, similar to dyslexic children using alphabetic languages, may also have a problem with orthographic reading.

On the nature of consonant/vowel differences in letter position coding: Evidence from developing and adult readers.

In skilled adult readers, transposed-letter effects (jugde-JUDGE) are greater for consonant than for vowel transpositions. These differences are often attributed to phonological rather than orthographic processing. To examine this issue, we employed a scenario in which phonological involvement varies as a function of reading experience: A masked priming lexical decision task with 50-ms primes in adult and developing readers. Indeed, masked phonological priming at this prime duration has been consistently reported in adults, but not in developing readers (Davis, Castles, & Iakovidis, 1998). Thus, if consonant/vowel asymmetries in letter position coding with adults are due to phonological influences, transposed-letter priming should occur for both consonant and vowel transpositions in developing readers. Results with adults (Experiment 1) replicated the usual consonant/vowel asymmetry in transposed-letter priming. In contrast, no signs of an asymmetry were found with developing readers (Experiments 2-3). However, Experiments 1-3 did not directly test the existence of phonological involvement. To study this question, Experiment 4 manipulated the phonological prime-target relationship in developing readers. As expected, we found no signs of masked phonological priming. Thus, the present data favour an interpretation of the consonant/vowel dissociation in letter position coding as due to phonological rather than orthographic processing.

How do Scrabble players encode letter position during reading?

A number of experiments with skilled adult readers have shown that a transposed-letter pseudoword (e.g., CHOLOCATE) is considerably more word-like than a control replacement-letter pseudoword (e.g., CHOTONATE). For instance, in lexical decision, response times are longer and less accurate for CHOLOCATE than for CHOTONATE (i.e., a transposed-letter effect). Here, we examined how letter position coding is attained in individuals who excel in orthographic-lexical processing: competitive Scrabble players. To this end, we conducted a lexical decision experiment with two types of pseudowords (transposed-letter vs. replacement-letter pseudowords). Data showed that while the transposed-letter effect does occur in expert Scrabble players, the magnitude of the effect is dramatically smaller than in a control group of university students—in particular, for the accuracy data. The parameters responsible for the flexibility of letter position coding in models of visual word recognition must be modulated by the degree of expertise in orthographic-lexical processing.

Does location uncertainty in letter position coding emerge because of literacy training?

In the quest to unveil the nature of the orthographic code, a useful strategy is to examine the transposed-letter effect (e.g., JUGDE is more confusable with its base word, JUDGE, than the replacement-letter nonword JUPTE). A leading explanation of this phenomenon, which is line with models of visual attention, is that there is perceptual uncertainty at assigning letters ("objects") to positions. This mechanism would be at work not only with skilled readers but also with preliterate children. An alternative explanation is that the transposed-letter effect emerges at an orthographic level of processing as a direct consequence of literacy training. To test these accounts, we conducted a same-different matching experiment with preliterate 4-year-old children using same versus different trials (created by letter transposition or replacement). Results showed a significantly larger number of false positives (i.e., "same" responses) to transposed-letter strings than to 1/2 replacement-letter strings. Therefore, the present data favor the view that the visual processing of location information is inherently noisy and rule out an interpretation of confusability in letter position coding as emerging from literacy training. (PsycINFO Database Record