Transposed-letter effects in reading: Evidence from eye movements and parafoveal preview.

Three eye movement experiments were conducted to examine the role of letter identity and letter position during reading. Before fixating on a target word within each sentence, readers were provided with a parafoveal preview that differed in the amount of useful letter identity and letter position information it provided. In Experiments 1 and 2, previews fell into 1 of 5 conditions: (a) identical to the target word, (b) a transposition of 2 internal letters, (c) a substitution of 2 internal letters, (d) a transposition of the 2 final letters, or (e) a substitution of the 2 final letters. In Experiment 3, the authors used a further set of conditions to explore the importance of external letter positions. The findings extend previous work and demonstrate that transposed-letter effects exist in silent reading. These experiments also indicate that letter identity information can be extracted from the parafovea outside of absolute letter position from the first 5 letters of the word to the right of fixation. Finally, the results support the notion that exterior letters play important roles in visual word recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The stimulus suffix effect and positional uncertainty.

Conducted 2 serial recall experiments with 68 undergraduates to determine if a stimulus suffix creates positional uncertainty that contributes to the suffix effect. In Exp 1, Ss recalled all or some of 8 auditorily presented letters. During recall, nontested letters were shown in position to reduce uncertainty about position. In Exp 2, nontested letters were not shown during recall. Despite differences between the 2 experiments, the serial position functions were almost identical. It is concluded that positional uncertainty is a component of the terminal suffix effect but not of preterminal suffix effects. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Presenting words without interior letters: Superiority over single letters and influence of postmask boundaries.

In 5 experiments with a total of 32 Ss, exterior letter pairs from 4-letter words (e.g., d??k from dark) were presented in pattern-postmasked displays, in the positions they would occupy if the whole word were shown. In Exp 1, letter pairs (d??k) were reported more accurately than single letters (d) (the pair–letter effect). In Exps 2 and 3, performances with letter pairs dropped to those for single letters when each letter in a pair was masked individually or when masks were much wider than letter pairs. In Exps 4 and 5, the pair–letter effect and mask influence were both removed when one letter in each pair was replaced by a number sign (d??#) or when letter pairs were not the exterior letters of real words (e.g., y??f). These findings suggest that the exterior letter combinations of words are represented psychologically and access to these representations is affected by mask configuration. Implications for current word-recognition models are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Position and order information in recognition memory.

In three experiments we examined short-term recognition memory for order information. In each, a target string of letters was followed by a test string to which the subject responded "same" or "different." The test string either was identical to the target, or it included a transposition of a single pair of letters. Results were consistent in showing that the closer two transposed letters were to another in the target string, the poorer was the recognition of transposition. A probed recall procedure introduced in Experiment 3 required subjects to identify the serial position in the target string held by the probe letter. This procedure showed that memory for a letter's serial position was distributed over a number of serial positions and that the overlap of such positional uncertainty functions for individual pairs of adjacent items predicted recognition memory for transposition. Uncertainty about position of occurrence appears to determine order information, at least in part, and constitutes a neglected aspect of current theories of serial-position phenomena. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Order of processing in visual perception.

Three experiments tested predictions derived from 3 cognitive scanning hypotheses proposing respectively a left-to-right, ends-first, and peripheral-foveal order of scanning. In Exps I and II configurations of letters and/or digits were presented to 11 Ss around a central fixation point, and the stimulus was followed by a 1-sec presentation of a patterned mask or a blank white field. Backward masking selectively impaired the identification of stimuli in foveal positions whether or not these stimuli occupied middle-of-row positions. In Exp III 4 Ss made a manual same-different response to the presence or absence of a critical letter presented 3Deg. to the left or right of fixation. Noise letters appeared on either side or both sides of the critical letter. Identification response times were faster when the critical letter appeared in the left-most position in left field arrays and the right-most position in right field arrays. Principal conclusions drawn from the 3 experiments were: (a) Alphanumeric stimuli are scanned from the peripheral visual field inward towards fixation. (b) Any left-to-right scanning occurs relatively late in iconic processing. (c) An ends-first scanning strategy is a particular case of a more general peripheral-foveal strategy. (French summary) (40 ref) (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)     

Immediate spatial order memory and item memory in sixth-grade children as a function of reader ability.

16 good and 16 poor 6th-grade readers served as Ss. Exp I tested immediate order memory for strings of 4 and 6 consonants that were either redundant (R) or nonredundant (NR) based on positional frequencies of letters in printed English. Both reader groups were better in retrieving order for R strings; poor readers were inferior to good readers on both R and NR 6-letter strings. Exp II tested for immediate order memory and immediate item memory for strings of 8 digits and strings of 8 consonants. Good readers were better than poor readers on all tasks. However, order memory appeared to be more strongly related to reading ability than was item memory. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive capacity differences among writers.

Examined differences between good and poor writers on 6 cognitive-processing tasks. In Exp I, 3 tasks were employed to ascertain differences between 15 good and 15 poor undergraduate writers on recall and manipulation of information: an ordered letters task, an iconic memory task, and a letter reordering task. In Exp II, 3 additional tasks were employed to examine 17 good and 16 poor undergraduate writers' abilities to hold and manipulate larger amounts of information: a word reordering task, a sentence reordering task, and a paragraph assembly task. In both experiments, the results reveal significant differences between good and poor writers' abilities to hold and simultaneously manipulate information. Exp III replicated the results of Exps I and II with 15 good and 14 poor high school writers. It is suggested that the observed differences between good and poor writers can be attributed to differences in elementary information-processing programs. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Letter legibility and visual word recognition

Word recognition performance varies systematically as a function of where the eyes fixate in the word. Performance is maximal with the eye slightly left of the center of the word and decreases drastically to both sides of this optimal viewing position. While manipulations of lexical factors have only marginal effects on this phenomenon, previous studies have pointed to a relation between the viewing position effect (VPE) and letter legibility: When letter legibility drops, the VPE becomes more exaggerated. To further investigate this phenomenon, we improved letter legibility by magnifying letter size in a way that was proportional to the distance from fixation (e.g., TABLE). Contrary to what would be expected if the VPE were due to limits of acuity, improving the legibility of letters has only a restricted influence on performance. In particular, for long words, a strong VPE remains even when letter legibility is equalized across eccentricities. The failure to neutralize the VPE is interpreted in terms of perceptual learning: Since normally, because of acuity limitations, the only information available in parafoveal vision concerns low-resolution features of letters; even when magnification provides better information, readers are unable to make use of it.     

Search for a singular word or nonword.

Observers looked for an out-of-category item, either a singular word in a list of nonwords (i.e., random collections of letters) or a singular nonword in a list of words. When list items were presented simultaneously (Exp 1), words were detected faster than nonwords, but a singular word in a nonword list was missed more often than a singular nonword in a word list. These results are consistent with the internal-noise principle (INP). According to the INP, legal letter sequences are more likely to be misperceived as illegal than are illegal sequences as legal; thus, there was more rechecking of perceived nonwords than perceived words. With rapid serial visual presentation of list items (Exp 2), the effect of list type vanished. The missing-feature principle, which credits unresolved letters and features to legal letter sequences wherever possible, was as strong and evident as the INP during early processing. (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)     

Letter encoding in visual word identification: More evidence for a word-integration explanation for parafoveal preview effects in reading.

A letter string presented briefly in the parafovea facilitates naming a foveally presented word provided that the two stimuli are orthographically similar. The facilitation is asymmetrical in that to obtain it, both letter strings must have the first letters in common. One possible explanation, a letter-integration hypothesis, proposes that readers only identify the letters at the beginning of the parafoveal stimulus, an action that facilitates processing the target. Another explanation, a word-integration hypothesis, postulates that all the letters of the parafoveal stimulus are identified and that the asymmetry occurs because the first letters of the parafoveal stimulus are weighted more heavily than the later ones. The two accounts differ in the way the position of the first letter is determined. To distinguish the views, English and Hebrew stimuli were presented to 7 bilingual readers. 12 normal students participated as controls. Readers could not anticipate the position of the first letters; hence, if the letter-integration explanation is correct, the asymmetry in the priming should be attenuated. Consistent with the word-integration explanation, however, priming occurred when the target shared the beginning letters with the prime in both languages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What Do Letter Migration Errors Reveal About Letter Position Coding in Visual Word Recognition?

Dividing attention across multiple words occasionally results in misidentifications whereby letters apparently migrate between words. Previous studies have found that letter migrations preserve within-word letter position, which has been interpreted as support for position-specific letter coding. To investigate this issue, the authors used word pairs like STEP and SOAP, in which a letter in 1 word could migrate to an adjacent letter in another word to form an illusory word (STOP). Three experiments show that both same-position and adjacent-position letter migrations can occur, as well as migrations that cross 2 letter positions. These results argue against position-specific letter coding schemes used in many computational models of reading, and they provide support for coding schemes based on relative rather than absolute letter position. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading mutilated text.

Conducted 2 experiments, one with 12 6th graders considered to be good readers and one with 12 junior high and high school students who had normal IQs but were 2 yrs behind on standardized reading scores. Ss read passages of text which had been mutilated by changing the shape of the words and/or the initial, medial, or final letter of words. When the shape had been maintained by replacing letters with letters that shared distinctive features and were visually confusable with them, less reading time was taken and fewer errors were made than when the shape had been altered by replacing letters with letters that were not visually confusable with them. In addition, mutilations to the beginning of a word were considerably more disruptive than mutilations to the middle or end of a word. Good readers and poor readers showed highly similar data patterns. (15 ref) (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)     

A theory of order relations in perceptual matching.

Relates order relations to research on retrieval processes and the representation of order information in memory. In 2 experimental tests, presentation of a study string of letters was followed by a test string to which the 6 undergraduate Ss responded "same" or "different." When adjacent letters were switched, RT was long and accuracy low, suggesting that a test letter is not simply compared to the letter in the same position in the study string; rather, the comparison is distributed across positions. The memory model assumes that the representation of a letter is distributed over position and that the comparison process assesses the amount of overlap between the test string and the memory representation. The diffusion retrieval model and overlap memory model are fitted to the data and goodness-of-fit is assessed. Shortcomings of alternative models are considered and applications of the model to related matching tasks, such as D. Taylor's (1976) converse of the perceptual matching task, and Angiolillo-Bent and L. Rips's (1981) multiple-element comparison task, are described. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading speed in pure alexia

This study investigated possible causes of differences in reading speed between two alexic patients who read words letter by letter. As both patients appeared to rely on serial left-to-right processing of letters within words, the difference in reading speed did not seem to be related to any differences in the extent to which the patients could recognize letters in words in parallel or 'ends-in'. Differences in reading speed also seemed to be unrelated to the patients ability to identify individual letters since their letter recognition accuracy was very similar. Furthermore, although patient PD was significantly slower at reading words aloud than patient DC, PD was in fact significantly quicker than DC on a test that has previously been used to assess letter recognition skills in letter-by-letter readers. It is therefore concluded that PD reads words more slowly because of an additional impairment at the level of the word form system. The results therefore reinforce the distinction between Type 1 and Type 2 letter-by-letter readers that was first drawn by Patterson and Kay.     

Echoic memory processes in good and poor readers.

Conducted 4 experiments to determine whether echoic memory plays a role in differences between good and poor readers. In Exp I, with 9 poor (mean age 11.05 yrs) and 9 good (mean age 10.9 yrs) readers, and Exp II, with 12 poor (mean age 10.85 yrs) and 12 good (mean age 10.7 yrs) readers, a suffix procedure was used in which the S was read a list of digits with either a tone control or the word go appended to the list. For lists that exceeded the length of the Ss' memory span by 1 digit (i.e., that avoided ceiling effects), poor readers showed a larger decrement in the suffix condition than did good readers. In Exp III, with 14 poor (mean age 10.64 yrs) and 14 good (mean age 10.83 yrs) readers, Ss shadowed words presented to 1 ear at a rate determined to give 75–85% shadowing accuracy. The item presented to the nonattended ear were words and an occasional digit. At various intervals after the presentation of the digit, a light signaled that the S was to cease shadowing and attempt to recall any digit that had occurred in the nonattended ear recently. Whereas good and poor readers recalled the digit equally if tested immediately after presentation, poor readers showed a faster decline in recall of the digit as retention interval increased. In Exp IV, using Ss from Exp II, bursts of white noise were separated by 9–400 msec of silence, and the S was to say whether there were 1 or 2 sounds presented. There were no differences in detectability functions for good and poor readers. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serial position effects in the identification of letters, digits, and symbols.

In 6 experiments, the authors investigated the form of serial position functions for identification of letters, digits, and symbols presented in strings. The results replicated findings obtained with the target search paradigm, showing an interaction between the effects of serial position and type of stimulus, with symbols generating a distinct serial position function compared with letters and digits. When the task was 2-alternative forced choice, this interaction was driven almost exclusively by performance at the first position in the string, with letters and digits showing much higher levels of accuracy than symbols at this position. A final-position advantage was reinstated in Experiment 6 by placing the two alternative responses below the target string. The end-position (first and last positions) advantage for letters and digits compared with symbol stimuli was further confirmed with the bar-probe technique (postcued partial report) in Experiments 5 and 6. Overall, the results further support the existence of a specialized mechanism designed to optimize processing of strings of letters and digits by modifying the size and shape of retinotopic character detectors' receptive fields. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The repetition effect: A further test of the clarity-enhancement explanation.

Presented single letters with varying numbers of repeated brief exposures to a total of 21 undergraduates. After each presentation, the S classified the target letter as belonging to either the 1st or the 2nd half of the alphabet. In Exp I, the S knew that all presentations of a trial would have the same target letter. In Exp II, the S knew that a catch letter from the opposite half of the alphabet might be shown on each succeeding presentation. The S's discriminative ability, as assessed by the nonparametric index A', increased as a function of trial length in Exp I but not in Exp II. In neither experiment was response bias related to trial length. Data are interpreted as being incompatible with a clarity-enhancement explanation of repeated presentations. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)