Alphabetic sequence decisions for letter pairs with separations of one to three letters.

The alphabet storage and retrieval theory of Klahr, Chase, and Lovelace (1983) was tested for applicability to letter-order decisions. Ss judged whether letter pairs with sequential separations of 1, 2, or 3 letters were in correct or incorrect order. Ss made decisions either in a continuous- or intermittent-attention mode. The results for alphabetic letter-order decisions with a letter separation of 1 were in conformance with the theory of Klahr et al. in both attention modes. However, at letter separations of 2 and 3 letters, Ss made decisions that were more compatible with a symbolic-distance mechanism. Speculation on how Ss could make alphabetic-order decisions in either a memory-consultation or a symbolic-distance manner is made.     

Memory representation of alphabetic position and interval information.

The authors conducted 3 sets of experiments. In the 1st set of experiments, participants made alphabetic position estimations. In the 2nd set, participants made interletter distance estimations. In the 3rd set, they made comparative judgments of the alphabetic order of a pair of letters. The results showed that participants had highly accurate ordinal level information about the alphabet in memory but that interval level information was systematically distorted. In addition, alphabetic serial information was found to be used in 2 distinct modes in memory, depending on whether the representation could be contained within the span of immediate memory.     

Confusability and interference between members of parafoveal letter pairs

In each of three experiments, confusability between members of a parafoveally exposed pair of letters affected accuracy of identifying the peripheral, but not the central, letter. Confusability was determined from a confusion matrix developed for each subject. In Experiment 1, only one letter in each pair was identified on each exposure, and the position of pair members was varied over trials while the absolute position of the pair was held at a constant distance from fixation. In Experiment 2, both letters were identified on each exposure. In Experiment 3, the criterion letter was presented at a constant distance from fixation, and both letters were identified on each exposure. Since results in Experiment 3 were the same as in Experiments 1 and 2, the effect cannot be explained with reference to an interaction between confusability and acuity. The implications of the findings for various models of visual information processing are discussed.     

Acquisition process of typing skill using hierarchical materials in the Japanese language

In the present study, using a new keyboard layout with only eight keys, we conducted typing training for unskilled typists. In this task, Japanese college students received training in typing words consisting of a pair of hiragana characters with four keystrokes, using the alphabetic input method, while keeping the association between the keys and typists’ finger movements; the task was constructed so that chunking was readily available. We manipulated the association between the hiragana characters and alphabet letters (hierarchical materials: overlapped and nonoverlapped mappings). Our alphabet letter materials corresponded to the regular order within each hiragana word (within the four letters, the first and third referred to consonants, and the second and fourth referred to vowels). Only the interkeystroke intervals involved in the initiation of typing vowel letters showed an overlapping effect, which revealed that the effect was markedly large only during the early period of skill development (the effect for the overlapped mapping being larger than that for the nonoverlapped mapping), but that it had diminished by the time of late training. Conversely, the response time and the third interkeystroke interval, which are both involved in the latency of typing a consonant letter, did not reveal an overlapped effect, suggesting that chunking might be useful with hiragana characters rather than hiragana words. These results are discussed in terms of the fan effect and skill acquisition. Furthermore, we discuss whether there is a need for further research on unskilled and skilled Japanese typists.     

Multiple number and letter comparison: directionality and accessibility in numeric and alphabetic memories

In 3 experiments, subjects made comparativejudgments on a set of 2 numbers or letters, 3 numbers or letters, or 5 numbers or letters. Numeric and alphabetic serial order memories were contrasted. Three aspects of serial order memory processes were identified: computational complexity, directionality, and accessibility. Computational complexity is the number of algorithmic steps involved in identifying a target. Directional bias is measured as the speed differences in identifying serial targets of equal computational complexity in a stimulus array. Memory accessibility is measured as the numeric and alphabetic serial position effects. Subjects had a slight directional bias favoring backward ordering for single digits but no bias in 2-digit number ordering, in contrast to a strong forward directional advantage in letter ordering. The speed of number access was found to steadily and evenly decrease along the numeric scale, in contrast to a systematic pattern of variations in alphabet access along the alphabetic scale. Finally, the middle item effect (the middle item in a multi-item array is identified most slowly) found in Jou's (1997) multiple-letter comparison study was generalized to numbers.     

Application of geometric models to letter recognition: distance and density

This article reviews studies in which a single letter is visually presented under adverse conditions and the subject's task is to identify the letter. The typical results for such studies are (a) certain pairs of letters are more often confused than other pairs of letters; (b) certain letters are more easily recognized than others; and (c) confusion errors for a letter pair are often asymmetric, the number of errors differing depending on which letter of the pair is presented as the stimulus. A geometric model incorporating the properties of distance and spatial density (after Krumhansl) is presented to account for these results. The present application of the distance-density model assumes that each letter is constructed in a typical 5 X 7 dot matrix. Each letter is represented in 35-dimensional space based on its constituent dots. A central idea behind the model, embodied in the property of spatial density, is that an explanation of typical results must take into account the relationship of the entire stimulus set to both the presented letter and the responded letter. Specifically, according to the model, (a) pairs of letters that are close in geometric space are more often confused than pairs of letters that are distant; (b) letters that are in less spatially dense regions are more easily recognized than letters that are in more spatially dense regions; and (c) asymmetric confusion errors result when one member of a letter pair is in a denser region than the other member of the letter pair. The distance-density model is applied to published and unpublished results of the authors as well as published results from two other laboratories. Alternative explanations of the three typical letter recognition results are also considered. The most successful alternative explanations are (a) confusions are an increasing function of the number of dots that two letters share; (b) letters constructed from fewer dots are easier to recognize; and (c) asymmetries arise when one member of a letter pair is more easily recognized, since that letter then has fewer confusion errors to give to the other letter of the pair. The model is discussed in terms of the distinction between template matching and feature analysis. An alternative classification of letter recognition models is proposed based on the global versus local qualities of features and the spatial information associated with each feature. The model is extended to explain reaction time study results. It is suggested that the distance-density model can be used to create optimal letter fonts by minimizing interletter confusions and maximizing letter recognizability.     

The Foundations of Literacy

Learning to read and write in English requires children to master the alphabetic principle, the idea that the letters in printed words represent the sounds in spoken words in a more or less regular manner. Children need at least two skills in order to grasp the alphabetic principle. The first is phonological awareness, or a sensitivity to the sound structure of spoken words. The second is knowledge about letters, including knowledge of letter names and knowledge of letter sounds. Recent research sheds light on these foundational skills, documenting the linguistic factors that affect children's performance and how children put their phonological skills and knowledge of letters to use in learning to read and spell.     

Processing sets of letters for order: Evidence from reaction time experiments

In two experiments, subjects were required to impose different levels of organization on randomly ordered letters. In a between-subject design, the subject was to identify the letter in the set coming first in the alphabet or to reorganize the set into an alphabetic sequence. In a within-subject design, presentation of the letters was followed by an instruction to carry out the identification or reorganization task or to recite the letters in left-to-right order. Reaction time varied systematically with level of required organization, size of the presented set, and position and spacing of the letter set in the alphabet. The results are discussed in terms of two simple models.     

Processing of sequentially presented letters

The effect on the number of letters S can report of the duration of each sequentially presented letter was compared with that of processing time, defined as the time from the onset of a letter to the onset of the next letter. Four Ss were each shown 1250 common English words, from four to eight letters long, one letter at a time. Each letter acted as a visual noise field for the preceding letter. The duration of each letter and the interval between letters was varied independently. The S reported the letters he saw after each word was displayed. It was found that the processing time (onset to onset) predicted the number of letters correctly reported, regardless of the partition between on time and off time. A calculation was made of the number of milliseconds of on plus off time that are needed to ensure correct report of each letter. This time was independent of the duration of the processing time, but was positively correlated with the number of letters in the word. This correlation is probably in part artifactual, so that no claim can be made that it takes longer to process a letter of a long as compared to a short word.     

Processing of tachistoscopic displays with controlled order of characters and spaces

The task used was designed to force Ss consistently to process the letters of a tachistoscopic display in the same spatial order, if Ss are able to process the letters in a brief display serially and if Ss have enough voluntary control over the selection of a processing order to use the order chosen by the E. In the main series of experiments the set of slides shown in each session included slides having a blank space in some position in the linear array of letters. For control, no-blank slides, a sharp, monotonic decrease in the percentage of correct detections of a signal letter with distance of the signal letter from the focusing dot was obtained. An unexpected result from the slides having a blank space was that detection of the signal letter was considerably more accurate on the slides having a blank space immediately following the signal letter than on the control slides having no blank space or the slides having a blank space immediately before the signal letter in the processing order. In one experiment blank spaces were replaced by black rectangles with no substantial change in the pattern of results. The results from the slides having a blank space or a black rectangle were interpreted as indicating that the onset of processing the image of a letter was determined by the distance in the display from the focusing dot to the letter and that the duration of processing an image of a letter was determined by the distance in the display from the letter to the next letter in the processing order.     

Cambridge University versus Hebrew University: The impact of letter transposition on reading English and Hebrew

Is reading similarly affected by letter transposition in all alphabetic orthographies? “The Cambridge University effect,” demonstrating that jumbled letters have little effect on reading, was examined using rapid serial visual presentation (RSVP) in English and in Hebrew. Hebrew-English bilinguals were presented sentences in both languages containing words with transposed letters. Sentences were presented rapidly on the screen word by word, and participants had to reproduce the sequence of words perceived. We found a marked difference in the effect of transpositions in the two languages. In English, transpositions had little effect on performance, whereas in Hebrew, performance deteriorated dramatically for words with transposed letters. The differential effects of transposition are accounted for by the difference in lexical organization in Hebrew and in English, suggesting that models of reading in alphabetic orthographies may be language specific.     

Automatic letter priming in an alphabetic decision task

An alphabetic decision task was used to study effects of form priming on letter recognition at very short prime durations (20 to 80 msec). The task required subjects to decide whether a stimulus was a letter or a nonletter. Experiment 1 showed clear facilitatory effects of primes being either physically or nominally identical to the targets, with a stable advantage for the former. Experiment 2 demonstrated that uppercase letters are classified more rapidly as letters (vs. non-letters) when they are preceded by a briefly exposed, forward- and backward-masked, visually similar uppercase letter than when they are preceded by a visually dissimilar uppercase letter. Finally, Experiment 3 demonstrated that nominally identical and visually similar primes facilitate processing more than do nominally identical, visually dissimilar primes. The alphabetic decision task proved to produce sensitive and stable priming effects at the feature, letter, and response-choice level. The present results on letter-letter priming thus constitute a solid data base against which to evaluate other priming effects, such as word-letter priming. The results are discussed in light of current activation models of letter and word recognition and are compared with data simulated by the interactive activation model (McClelland & Rumelhart, 1981).     

Identity without form: Abstract representations of letters

Subjects viewed single letters and orthographically regular pseudowords in a tachistoscope at threshold duration. The pseudowords were either all of one case (upper or lower) or they were of mixed case. Letter identity (“A”) and case judgments were required for one letter on each trial. It was found that letter identity was often reported correctly when case was reported incorrectly, even for letters whose upper- and lowercase forms are physically dissimilar (e.g., G-g). This “case effect” was stronger for letters in pseudowords than for letters presented alone. It held across different type fonts, and it occurred even when the upper-and lowercase letters were of different sizes (gEaT) and when the instructions to the subjects stressed the greater importance of case reports over identity reports. The results are consistent with the view that letter identification is an automatic process, the product of which is an abstract representation containing no information about physical form.     

ScanMatch: A novel method for comparing fixation sequences

We present a novel approach to comparing saccadic eye movement sequences based on the Needleman-Wunsch algorithm used in bioinformatics to compare DNA sequences. In the proposed method, the saccade sequence is spatially and temporally binned and then recoded to create a sequence of letters that retains fixation location, time, and order information. The comparison of two letter sequences is made by maximizing the similarity score computed from a substitution matrix that provides the score for all letter pair substitutions and a penalty gap. The substitution matrix provides a meaningful link between each location coded by the individual letters. This link could be distance but could also encode any useful dimension, including perceptual or semantic space. We show, by using synthetic and behavioral data, the benefits of this method over existing methods. The ScanMatch toolbox for MATLAB is freely available online (www.scanmatch.co.uk).     

Alphabet knowledge and early literacy skills in French beginning readers

Numerous studies in various alphabetic languages have shown that letter knowledge is a strong predictor of reading and spelling achievement. However, this issue has rarely been addressed in French. Three studies are reported in order to examine the question of the development of letter knowledge in connection with literacy skills in French beginning readers before and during formal instruction. The level of the different alphabet-related skills was studied in kindergarten and two short longitudinal studies were conducted while the children were receiving formal instruction. In Study 1, upper-case letters resulted in higher scores. In Study 2, in the case of consonants, no significant advantage of phoneme position in letter names was found. In Study 3 children with good letter-name knowledge in kindergarten performed better in reading and spelling tasks in first grade. Finally, alphabet knowledge is viewed as a multi-faceted type of knowledge, which includes different skills such as alphabet reciting, letter naming and letter-sound knowledge. An early ability in this domain could be highly predictive of subsequent literacy development.     

Orthographic structure versus morphological structure: principles of lexical organization in a given language

Most models of visual word recognition in alphabetic orthographies assume that words are lexically organized according to orthographic similarity. Support for this is provided by form-priming experiments that demonstrate robust facilitation when primes and targets share similar sequences of letters. The authors examined form-orthographic priming effects in Hebrew, Arabic, and English. Hebrew and Arabic have an alphabetic writing system but a Semitic morphological structure. Hebrew morphemic units are composed of noncontiguous phonemic (and letter) sequences in a given word. Results demonstrate that form-priming effects in Hebrew or Arabic are unreliable, whereas morphological priming effects with minimal letter overlap are robust. Hebrew bilingual subjects, by contrast, showed robust form-priming effects with English material, suggesting that Semitic words are lexically organized by morphological rather than orthographic principles. The authors conclude that morphology can constrain lexical organization even in alphabetic orthographies and that visual processing of words is first determined by morphological characteristics.     

Locus of selectivity in a visual memory task using a color value indicator

Selection of high vs low valued letters from a briefly presented visual array was investigated. An indicator specifying the value of letters occurred before or after the array. Selection could occur during input to memory or during output from memory in the before condition, but only at output in the after condition. Previous research using an alphabetic instruction, which required letter identification prior to selection, attributed selection to output. A color instruction in the -present experiment, not requiring letter identification, showed the locus of selection to be at input. Experiment 2 replicated these findings and used an interference technique to add further support. In addition, contrary to previous findings, these results indicated that the selection process caused no deficit in overall recall.     

Facilitating Effect of Multisensory Letter Encoding on Reading and Spelling in 5‐Year‐Old Children

This study aims at identifying the effect of training in the acquisition of the alphabetic principle in 5‐year‐old children. We compared the effect of multisensory training of letters in visual, haptic, graphomotor, visuo‐haptic, and visuo‐graphomotor groups. For each training type, we contrasted trained versus untrained letters in reading and spelling tasks. First, visuo‐haptic and visuo‐graphomotor training improved letter‐sound correspondence acquisition scores more than the other types of training, and this improvement persisted in the second post‐test. A cross‐modal transfer was revealed by the fact that scores increased after blindfold haptic and graphomotor experiences. Moreover, performance on untrained letters also improved, suggesting an indirect effect following the specific trained letters training. The results argue in favor of a facilitating effect of multisensory encoding on acquisition of the alphabetic principle. Practical implications for the prevention of future reading difficulties are discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

On letter frequency effects

In four experiments we examined whether the frequency of occurrence of letters affects performance in the alphabetic decision task (speeded letter vs. pseudo-letter classification). Experiments 1A and 1B tested isolated letters and pseudo-letters presented at fixation, and Experiments 2A and 2B tested the same stimuli inserted at the 1st, 3rd, or 5th position in a string of Xs. Significant negative correlations between letter frequency and response times to letter targets were found in all experiments. The correlations were found to be stronger for token frequency counts compared with both type frequency and frequency rank, stronger for frequency counts based on a book corpus compared with film subtitles, and stronger for measures counting occurrences as the first letter of words compared with inner letters and final letters. Correlations for letters presented in strings of Xs were found to depend on letter case and position-in-string. The results are in favor of models of word recognition that implement case-specific and position-specific letter representations.     

The visuo-haptic and haptic exploration of letters increases the kindergarten-children’s understanding of the alphabetic principle

This study examined the effect of incorporating a visuo-haptic and haptic (tactual-kinaesthetic) exploration of letters in a training designed to develop phonemic awareness, knowledge of letters and letter/sound correspondences, on 5-year-old children’s understanding and use of the alphabetic principle. Three interventions, which differed in the work on letters identity, were assessed. The letters were explored visually and haptically in “HVAM” training (haptic-visual-auditory-metaphonological), only visually in “VAM” training (visual-auditory-metaphonological) and visually but in a sequential way in “VAM-sequential” training. The three interventions made use of the same phonological exercises. The results revealed that the improvement in the pseudo-word decoding task was higher after HVAM training than after both VAM training and VAM-sequential training (which did not differ). The sequential exploration of the letters (independently of perceptual modalities involved) was not to be sufficient alone for explaining these results. Moreover, similar improvements in the letter recognition test and in the phonological awareness tests were observed after the three interventions. Taken together, the results show that incorporating the visuo-haptic and haptic exploration of letters makes the connections between the orthographic representation of letters and the phonological representation of the corresponding sounds easier, thus improving the decoding skills of young children.