Are individual or consecutive letters the unit affected by repetition blindness?

When 2 similar words (e.g., react reach) are briefly sequentially displayed, the 2nd word may be omitted from the report, a phenomenon known as repetition blindness (RB). Previous researchers have suggested that consecutive letters are the unit affected by RB. Six experiments provided new data on orthographic RB. Two letters at the beginning or end of words resulted in RB, as did alternating interior letters (tactile earthly) and 3 letters with different relative positions (arid bird). However, no RB was found with a single final letter (show view). Observed RB may reflect pattern completion because RB for pairs like throat theory was reduced when the nonrepeated letters (eory) were consistent with only a single word. The experiments point to a model of orthographic RB in which both individual letters and letter sequences of length 2 or more play a role. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Why is word recognition impaired by disorientation while the identification of single letters is not?

Past research has shown that speed of identifying single letters or digits is largely indifferent to orientation, whereas the recognition of single words or connected text is markedly disrupted by disorientation. In a series of four experiments, we attempted to reconcile these findings. The results suggest that disorientation does not impair the identification of the characters but disrupts the perception of their spatial arrangement. When spatial order information is critical for distinguishing between different stimuli, disorientation is disruptive because some rectification process is required to restore order information. Utilizing the similarity between the letter B and the number 13, we found strong effects of orientation when a stimulus was interpreted as the two-digit number 13 but not when interpreted as the single letter B. This, however, occurred only when the set of numbers to be classified included permutations of the same digits. Odd–even decisions on single-digit and two-digit numbers (Experiment 3) yielded strong effects of stimulus orientation for order-dependent numbers (e.g., 32), weaker effects for order-independent numbers (e.g., 24), and none for repeated-digit (e.g., 22) or single-digit numbers. Classification time for two-letter Hebrew words evidenced strong effects of orientation for words that differed only in letter order but much weaker effects for words that had no letters in common, even when these were embedded within some words that did (Experiment 4). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceiving exterior letters of words: Differential influences of letter-fragment and non-letter-fragment masks.

Previous research shows letter-fragment masks and non-letter-fragment fields have different effects on performance with briefly presented alphabetic targets. However, popular accounts of these differences ignore mask configuration. Over a series of experiments, configurational effects of letter-fragment (LF) and non-letter-fragment (NLF) masks were compared. When the configuration of LF masks matched word boundaries, performance with exterior letter pairs from words improved, whereas performance with illegal exterior-letter pairs and single letters was unaffected. When the same changes were made to NLF masks, only an overall drop in performance occurred, with no selective effect on target type. Although LF mask configuration selectively affected lexical processing, NLF mask configuration produced substantially different effects, indicating problems with contemporary accounts of masking differences that ignore influences of mask configuration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye movements when reading transposed text: The importance of word-beginning letters.

Participants' eye movements were recorded as they read sentences with words containing transposed adjacent letters. Transpositions were either external (e.g., problme, rpoblem) or internal (e.g., porblem, probelm) and at either the beginning (e.g., rpoblem, porblem) or end (e.g., problme, probelm) of words. The results showed disruption for words with transposed letters compared to the normal baseline condition, and the greatest disruption was observed for word-initial transpositions. In Experiment 1, transpositions within low frequency words led to longer reading times than when letters were transposed within high frequency words. Experiment 2 demonstrated that the position of word-initial letters is most critical even when parafoveal preview of words to the right of fixation is unavailable. The findings have important implications for the roles of different letter positions in word recognition and the effects of parafoveal preview on word recognition processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Word superiority over isolated letters: The neglected role of flanking mask contours.

When stimuli are presented in pattern-postmasked displays, performance is better for words than for isolated letters. Contemporary accounts of this word advantage emphasize the role played by mask contours that overlay the positions of letters in each stimulus; however, the precise effect of these overlying mask contours has never been empirically determined. The role of overlying and flanking (falling to the left and right of each word and isolated letter) mask contours in the word advantage over isolated letters was examined. A word advantage was obtained only when more flanking mask contours were shown with isolated letters than with words; when masks covered only the positions of letters in each stimulus, and thus no flanking mask contours were presented, the word advantage was removed or reversed. Implications for contemporary accounts of the word advantage over isolated letters are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing the importance of letter pairs in initial, exterior, and interior positions in reading.

Exterior letter pairs (e.g., d--k in dark) play a major role in single-word recognition, but other research (D. Briihl & A. W. Inhoff, 1995) indicates no such role in reading text. This issue was examined by visually degrading letter pairs in three positions in words (initial, exterior, and interior) in text. Each degradation slowed reading rate compared with an undegraded control. However, whereas degrading initial and interior pairs slowed reading rate to a similar extent, degrading exterior pairs slowed reading rate most of all. Moreover, these effects were obtained when letter identities across pair positions varied naturally and when they were matched. The findings suggest that exterior letter pairs play a preferential role in reading, and candidates for this role are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The contributions of phonological awareness and letter-name knowledge to letter-sound acquisition—a cross-classified multilevel model approach.

In the present study, we investigated critical factors in letter-sound acquisition (i.e., letter-name knowledge and phonological awareness) with data from 653 English-speaking kindergartners in the beginning of the year. We examined (a) the contribution of phonological awareness to facilitating letter-sound acquisition from letter names and (b) the probabilities of letter-sound acquisition as a function of letter characteristics (i.e., consonant–vowel letters, vowel–consonant letters, letters with no sound cues, and vowel letters). The results show that letter-name knowledge had a large impact on letter-sound acquisition. Phonological awareness had a larger effect on letter-sound knowledge when letter names were known than when letter names were unknown. Furthermore, students were more likely to know the sounds of consonant–vowel letters (e.g., b and d) than vowel–consonant letters (e.g., l and m) and letters with no sound cues (e.g., h and y) when the letter name was known and phonological awareness was accounted for. Sounds were least likely to be known for letters with no sound cues, but reliable differences from other groups of letters depended on students' levels of phonological awareness and letter-name knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facilitation of perception by spelling constraints.

Conducted 4 experiments in which a total of 42 undergraduates viewed tachistoscopic presentations of a consonant pair and were asked to recall which of 2 or 4 pairs had been presented. Performance was better when the arrangement of letters was constrained in some way than when that constraint was absent (e.g., when the letters K and V could appear together only in 1 order-KV-vs either order, KV or VK). The alternatives were chosen so that knowledge of the constraint would not help the Ss (e.g., KV and VK never appeared together as alternatives). The facilitation effect occurred even when constrained and unconstrained conditions were equated for frequency of letter pairs or of letters occurring in a given position. Effects were found for both order and sequence constraints, and facilitation persisted from day to day. These effects are inconsistent with models of perceptual learning which depend on frequency of exposure. The underlying mechanisms may also facilitate the recognition of words. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Priming by numb3r5 does not involve top-down feedback.

Using the same–different task, Perea, Du?abeitia, Pollatsek, and Carreiras (2009) showed that digits resembling letters (“leet digits”; e.g., 1 = I, 4 = A) primed pseudoword strings (e.g., V35Z3D–VESZED), but letters resembling digits (“leet letters”) did not prime digit strings (e.g., 9ES7E2–935732), and suggested that this is due to top-down feedback available for letter, but not digit, strings. Here we show that (a) single letters show as much leet priming as 3-letter words (Experiment 1); (b) leet priming is equally robust for digit strings and pseudowords when the string is 4 items long but not when 6 items long (Experiment 2); and (c) with 6-item strings, orthotactically illegal letter strings (e.g., OIAUEQ) behave just like digit strings (Experiment 3). These results indicate that the asymmetry in leet priming is not due to top-down feedback available selectively for letter strings. We offer an alternative explanation based on the Bayesian reader account of masked priming proposed by Norris and Kinoshita (2008), and the role played by the orthotactic knowledge used to extend the functional capacity of visual working memory involved in performing the same–different task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence against the computation of abstract letter identities in visual processing.

Conducted 2 studies conceptually similar to the study of D. Besner et al (see record 1985-05766-001) in which letter strings were reorganized into sets where the single letters that were different were phonologically similar (e.g., G vs C) or dissimilar (e.g., G vs K). Latencies for same–different decisions about mixed-case letter strings were faster when the different letters were phonologically dissimilar. Results suggested skilled readers access name codes of individual letters in making their speeded classifications. In the present studies with 16 undergraduates, phonological similarity was manipulated in either the 1st or 4th letter of a mixed-case 4-letter string. A similarity effect was found when the 1st letter was varied. Results are not consistent with the view that abstract letter identities are computed in the course of same–different decisions about simultaneously presented mixed-case displays. (French abstract) (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the recognition of words with inverted letters.

Conducted 2 experiments in which 24 Ss were asked to identify words with all or some of their letters inverted. The experiments differed only in the explicitness of the instructions given to Ss. In some cases the letters appearing upside down were inverted as 1 unit, and in other cases they were inverted by letter. It was found that when all the letters were inverted, recognition time was faster for unit inversion. When just a few of the letters in the words were inverted, recognition time was shorter when the inversion was letter by letter rather than by unit. Data are consistent with a model that assumes that when the stimulus is homogeneously misoriented unit correction is applied, and when such homogeneity does not exist piecemeal correction is applied. (French abstract) (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expected locations of digits and letters on ten-button keysets.

In an attempt to find out where people expect to find letters and numbers on each of six configurations of ten keys, 300 Ss were asked to write on keyset diagrams either letters or numbers in arrangements they felt were most natural. Results showed that people expect (1) to find numbers arranged in left-to-right order in horizontal rows starting with the top, (2) to find letters, two or three on a key, in the same arrangement, and (3) to find letters arranged in horizontal rows when numbers already on the keyset are so arranged, but when the numbers are arranged otherwise (e.g., in vertical columns) the Ss divided about equally in arranging the numbers in horizontal rows and in vertical columns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Position-specific masking and the word-letter phenomenon: Reexamining the evidence from the Reicher-Wheeler paradigm.

When choosing which of 2 equally plausible "critical" letters (e.g., n or h) was present in a briefly presented backward-pattern-masked target (the Reicher-Wheeler task), people are more accurate with words (e.g., show) than isolated letters (h). Contemporary accounts argue that pattern masks induce this word-letter phenomenon (WLP) because critical letters in words are more resistant to replacement from masking letter fragments occupying the same serial positions. The authors tested this notion by directly examining the effect of position-specific masking on critical-letter report using backward-pattern masks that occupied only each critical-letter position. Under these conditions, no WLP was observed, even though all noncritical letters in words were unmasked. However, a strong WLP was obtained when masks occupied all possible serial positions, including those of noncritical letters. Further experiments indicated that these masking effects were not confounded by attentional factors. Implications for contemporary accounts of the WLP and the structure of the word recognition system are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time courses of the negative and positive repetition effects.

Time courses of the negative repetition effect (NRE), a poorer detection of the target in noise-same-as-target than in noise-alternative-target displays, and its opposite, the positive repetition effect (PRE), were examined. Exp 1 showed that displays in which a low-contrast target was present with a high-contrast noise produced a larger NRE than did displays in which a contrast relationship between items was reversed. A negative contrast repetition effect (NCRE) was also found that was comparable to NRE. Exp 2 showed that dimensional Korean letters (e.g., and ) whose configural differences were apparent in orientation produced the largest PRE at a O-msec stimulus onset asynchrony, whereas featural Korean letters (e.g., and ) that differed in the number of elements yielded the largest NRE when a noise letter preceded a target letter by 50 msec. Exps 3A and 3B indicated that the NCRE may arise from spatial attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Concreteness-dependent associative priming: Separate lexical organization for concrete and abstract words.

Four experiments used associated, unrelated, and neutral ({blank}–word) pairs that varied on prime and target concreteness. In Experiment 1, associated targets were named faster than neutral targets when primes and targets were homogeneous for concreteness (i.e., concrete–concrete or abstract–abstract), but not when they were heterogeneous (i.e., concrete–abstract or abstract–concrete). Experiments 2 and 3, using lexical decision, showed priming for all pairs irrespective of prime and target concreteness. In Experiment 4, the prime was presented for 16.7 ms, followed immediately by a 168-ms random letter mask. Lexical decision times showed priming similar to that in Experiment 1. If priming in Experiments 1 and 4 reflected lexical processes, whereas priming in Experiments 2 and 3 entailed postlexical processes, then lexical processes may be functionally distinct for concrete versus abstract words. These findings are more consistent with dual-coding than common-coding explanations of concreteness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of structural and naming factors of letters upon the recognition of tachistoscopic letters (author''s transl)

To determine the nature of effects of a preceding letter stimulus upon the recognition of a following letter stimulus, 20 subjects were sequentially and tachistoscopically presented pairs of letters of pairs of random patterns, which consist of the same number of elements, and asked to judge whether they were "same" or "different" in form. Four variable interstimulus intervals (ISI) between the 1st stimuli and the 2nd stimuli were employed as parameters. Results obtained were as follows: (a) percentages of correct responses for the letters were not significantly different from those for the random patterns, and (b) percentages of correct responses for the "same" matching tasks were significantly higher than those for the "different" matching tasks, but, differences in number of correct responses between the two tasks diminished as ISI increased. These results reveal structural, rather than naming, effects of preceding letters in the information processing of matching single letters.     

The revelation effect: When disguising test items induces recognition.

Documented here is a bias whereby items are more likely to be judged as having been presented beforehand if they are disguised in some way and so have to be discovered or "revealed." The bias was found for test words that were unfolded letter by letter (Exps 1 and 3), presented with their letters either transposed (Exps 2 and 3) or individually rotated (Exps 4 and 5) or rotated as a whole (Exp 5), and for test numbers that were presented in the form of Roman numerals (Exp 6) or equations (Exp 7). The bias occurred both for items that were presented beforehand and for those that were not. No bias was found when words were judged, not for prior occurrence, but for typicality as category instances (Exp 8), lexicality (Exp 9), frequency of general usage (Exp 10), or number of times encountered during the preceding week (Exp 11). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

All letters are not equal: Subgraphemic texture in orthographic working memory.

A central issue in the study of reading and spelling has been to understand how the consistency or frequency of letter-sound relationships affects written language processing. We present, for the first time, evidence that the sound–spelling frequency of subgraphemic elements of words (letters within digraphs) contributes to the accuracy with which these letters are produced in spelling. We report findings from 2 studies that demonstrate that letters within digraphs display differential susceptibility to error under conditions of disruption to orthographic working memory (O-WM). In the 1st, O-WM was disrupted as a result of neurological damage; in the 2nd, O-WM disruption was produced in neurologically intact, skilled spellers under dual task conditions with a shadowing task carried out during spelling. In both studies, segments with low versus high levels of sound–letter convergence, a measure of the frequency of sublexical mappings, were more vulnerable to disruption even when factors such as letter position, consonant–vowel context, and phoneme-to-grapheme mapping probability of the digraphs were controlled. These results contribute to our understanding of the internal texture of orthographic representations, providing evidence that individual letters differ in their activation strength and, as a result, in their susceptibility to error. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Positional differences in performance on members of confusable and nonconfusable letter pairs.

Previous experiments by the present author (see PA, Vols 67:6977 and 70:7125) showed that a parafoveally presented letter is more accurately identified when flanked by a letter to its foveal side than when flanked by one to its peripheral side, but only if the 2 letters are nonconfusable. The present 4 experiments, with 65 undergraduates, indicated that the basis for this confusability–asymmetry interaction is not criterion or response bias, but rather that it occurs earlier in visual processing. In Exp I, the interaction was found when only 1 pair member was reported, thus eliminating response bias requiring the report of both letters as the source of the effect. In Exp II, the data were subjected to signal detection analysis, and the interaction persisted. In Exp III, pair members were presented simultaneously or in rapid sequence, and the interaction was found only with simultaneous presentations. In Exp IV, letters were used with upper- and lowercase counterparts that were quite different in shape. Uppercase letters that were most and least confusable for each S were paired for presentation in their uppercase or in mixed-case forms. The interaction occurred only with uppercase pairs. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)