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PubMed2006

Letter-by-letter processing in the phonological conversion of multiletter graphemes: searching for sounds in printed pseudowords.

Current models of word reading differ in their descriptions of how print-to-sound conversion is performed. Whereas a parallel procedure is generally assumed, the dual-route cascaded model developed by Coltheart and colleagues (Coltheart, Rastle, Perry, Langdon, and Ziegler, 2001) holds that the nonlexical conversion operates letter by letter, serially from left to right. An interesting aspect of the hypothesized serial procedure is that only the first letter of two-letter graphemes is thought to cause activation of its corresponding phonological code, the second letter of multiletter graphemes being directly merged with the preceding letter to form a complex grapheme. This hypothesis was examined in a task in which participants had to detect target phonemes in visually presented pseudowords. The data suggest that phonological codes associated with all the letters of the multiletter graphemes are activated.

Attention↗
PubMed1991

Letters to go: general practitioners' referral letters to an accident and emergency department.

OBJECTIVE: To investigate the content of general practitioners' referral letters to the Accident and Emergency (A&E) Department of a large regional hospital. METHOD: Two hundred and fourteen consecutive identifiable letters from general practitioners presented by patients over a four week period were reviewed. The accuracy and content of the letters was measured by the presence of 10 key items, and checked against the A&E notes when necessary. A further nine items were examined to discover whether the context of the referral had any influence on letter content. RESULTS: Information that was relatively poorly represented in the letters included social and personal background details, vital signs, regional examination findings, a management plan, and investigation results. The presence in the letter of a management plan or a clear presenting problem was found to be significantly associated with appropriate referrals. CONCLUSIONS: Poor referral letters may reflect a professional distance between the general practitioner and A&E staff that is stretched by the anonymity of the relationship, increasing A&E specialisation, or lack of feedback to the general practitioner. Specific information standards for A&E referrals should be developed to ease contact and to establish criteria for referral.

Correspondence as Topic↗
PubMed1997

Referral letters: are form letters better?

An essential mode of contact between general practitioners (GPs) and hospital staff is the referral letter. This must be clear and concise with sufficient information to aid the GP, the consultant and the patient. In order to ensure this, a proposal was made for the use of a structured or standardized referral letter: a form letter. This report shows that form letters were shorter than typed letters. Form letters were also proven to contain more information than nonform letters.

Correspondence as Topic↗
PubMed1989

Event-related potentials during memory search and selective attention to letter size and conjunctions of letter size and color.

The analysis of event-related potentials was used in two experiments to investigate the structure of information processing in a task in which subjects selectively attended to letter size (Experiment 1) or a conjunction of letter size and color (Experiment 2) and searched for target letters within the attended stimulus category. The event-related potentials showed that selective attention to letter size resulted in the enhancement of a central N2b component (onset about 200 ms), which was assumed to reflect feature nonspecific orienting of attention. When attention was directed to conjunctions of letter size and color an earlier effect was found (onset about 150 ms) consisting of positivity at the anterior electrodes and negativity at OZ. This earlier effect was assumed to reflect feature-specific selective processing. Although the early effect showed a hierarchical pattern of results, in which the effect of attending to size was contingent on the relevance of the color attribute, the N2b showed a more independent pattern of results, in which the relevance of either the color or the size attribute resulted in an enhancement of this component, independent of the relevance of the other attribute. An increase in the duration of the memory search process resulted in a prolonged negativity with an onset of about 200 ms which was maximal at CZ. In both experiments the initial phase of this negativity was also found in the event-related potentials to the unattended stimulus categories, suggesting that the search process was initiated nonselectively and terminated after the selection cues were identified. Detection of attended target letters resulted in a parietal P3b component. In both experiments there was an earlier effect discriminating targets and nontargets in the range 200-300 ms.

Adult↗
PubMed1985

An infrared system for the detection of a pigeon's pecks at alphanumeric characters on a TV screen: the dependency of letter detection on the predictability of one letter by another.

Three pigeons pecked at letters of the alphabet and at the symbol "?" displayed on a computer-driven cathode ray screen. A 4 by 4 matrix of infrared emitting and detecting diodes and associated circuitry identified the location of a pigeon's responses to the screen. Responses at the target letter T were probabilistically reinforced with food whenever T appeared in a string of three letters in the middle of the screen. Responses at the symbol "?" appearing below this string were probabilistically reinforced whenever T did not appear. The letter F anywhere in the three-character string either strongly predicted the occurrence of the target letter T, in two conditions, or predicted its nonoccurrence, in a third. This manipulation of the frequency with which the familiar letter F predicted T was shown to change the function relating probability of a correct peck at the symbol "?" to the number of Fs in the string. This effect may be interpreted as an instance of the phenomenon where an organism's acquired knowledge changes what it sees.

Animals↗
PubMed1981

[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.

Form Perception↗
PubMed1990

Priming effects in a letter-by-letter reader depend upon access to the word form system.

Several types of cognitive and neuropsychological evidence suggest that priming effects on such implicit memory tests as word identification are mediated by a pre-semantic visual word form system that can operate independently of episodic memory. We investigate priming in a letter-by-letter reader, P.T., whose pattern of performance on neuropsychological tests indicates preservation of the word form system. Experiment 1 revealed robust priming on a word identification test following letter-by-letter study of target words, despite P.T.'s great difficulty in identifying non-studied words. Experiment 2 showed that the priming effect was modality specific whereas Experiment 3 indicated that recall of previously studied words was not modality specific, thus indicating that the observed priming could not be attributed to explicit memory strategies. Experiment 4 revealed no priming of illegal nonwords on a letter identification test. The results support the notion that priming on the word identification test depends on access to the word form system.

Attention↗
PubMed1992

Does letter-by-letter reading involve the spelling system?

Warrington and Shallice (Brain 103, 99-112, 1980) proposed that letter-by-letter readers can no longer access the visual word-form system, and read by using the spelling system 'in reverse'. Contrary to their suggestion, this paper presents the case of a letter-by-letter reader who appears to use quite different strategies in word reading and spelling. Reading and spelling are both impaired, but they appear to be impaired in different ways. Most strikingly, the patient's spelling errors consist largely of phonological regularizations--indeed there is little evidence that he has any lexical spelling knowledge available--whereas there are virtually no regularizations amongst his reading errors. These are largely visual paralexias and letter misidentifications. It is suggested that this pattern is more easily explained in terms of compensatory mechanisms that access the reading lexicon than by use of the spelling system 'in reverse'.

Adult↗
PubMed2005

Brain activations during letter-by-letter reading: a follow-up study.

Lesions affecting the ventral cortex of the left temporal lobe commonly yield a selective reading impairment known as pure alexia. It is thought to result from the disruption or deafferentation of the Visual Word Form Area (VWFA), a region in the left lateral occipitotemporal sulcus activated whenever normal subjects are viewing alphabetic strings. Most pure alexic patients retain the ability to identify single letters, and develop a strategy of letter-by-letter (LBL) reading. We recently studied fMRI activations in LBL readers and clarified the underlying mechanisms. However, LBL reading is a dynamic process which may improve over months or years of practice, although the cerebral bases of this continuing improvement are currently unknown. We had the opportunity to run the same behavioural testing and fMRI experiment a second time in an alexic patient, 8 months after collecting the data reported by Cohen et al. [Cohen, L., Henry, C., Dehaene, S., Molko, N., Lehéricy, S., Martinaud, O., Lemer, C., and Ferrieux, S. (2004). The pathophysiology of letter-by-letter reading. Neuropsychologia, 42, 1768-1780]. We analyze the changes that occurred over this period in the pattern of reading-related activations, while the patient's LBL reading improved. The activation level decreased in most of the overall network between the two sessions. This general trend contrasted with a focal increase restricted to specific left frontal and parietal areas. When studying the contrast between words and consonant strings, which may be taken as a correlate of LBL reading, we also found a general decrease, except for similar left frontal and parietal regions, which showed a significant increase. We suggest that the pattern of evolution fits with the minimal hypothesis of normal strategic abilities and skill learning, associated with perceptual tuning in right-hemispheric structures able to substitute the disrupted VWFA.

Adult↗
PubMed2001

Sheffield Assessment Instrument for Letters (SAIL): performance assessment using outpatient letters.

CONTEXT: Well-designed assessments of performance are urgently required for training doctors, and to provide indicators of the quality of practice. OBJECTIVES: To design an assessment process that uses routine outpatient letters, and to evaluate its validity, feasibility, reliability (reproducibility and discrimination) and potential educational impact. PARTICIPANTS: All 26 paediatric registrars in North Trent attending annual assessment panel in 1999 participated. STUDY DESIGN: An assessment instrument (SAIL) was developed from a consensus framework for good practice in written communication. It comprises an 18-point checklist and a global rating scale. Three judges applied the instrument to 260 letters from the routine clinical practice of the 26 participants. Results We achieved consensus on good practice in written communication. This was in keeping with the published literature. All participants completed the assessment. Scoring took 3-6 min per judge per letter. The reliability coefficient in this test situation is 0.72. Modelling predicts that a coefficient of 0.8 (the threshold for high-stakes judgements about performance) can be achieved with more judges or letters. The assessment results are well suited to formative feedback. CONCLUSIONS: SAIL uses letters as a face valid indicator of written communication performance. The instrument is feasible to use, and produces reliable results when applied to paediatric registrars to inform the annual Record of In-Training Assessment (RITA). Feedback from the assessment should help doctors to improve their written communication. Its use may extend to other specialities and settings including revalidation.

Communication↗
PubMed1994

Influence of letter size on age differences in letter matching.

We tested healthy young and older adults on a simultaneous presentation, letter-matching task that varied letter size. The goal of the experiment was to determine if older adults' higher baseline level of internal noise would affect age differences in letter-matching performance as letter size was varied. The results indicated that both young and older adults evidenced "fast-same" effects for RT and "false-different" effects for errors. However, older adults (compared to young adults) showed a larger "false-different" effect for errors, and this effect was especially pronounced for smaller letter pairs. These results imply that older adults' higher baseline levels of internal noise result in these individuals setting "compromise criteria" that underestimate the impact of internal noise.

Adolescent↗
PubMed2004

Applications of computer-based instruction: using specialized software to aid letter-name and letter-sound recognition.

We evaluated computerized training and testing programs with children who were having difficulties learning prereading skills. The programs were derived from equivalence research and were written in authoring software designed for educators. After learning to match uppercase and lowercase printed letters to the corresponding letter names (Tasks 1 and 2), the children matched the letters to one another (Tasks 4 and 5). Then, after learning to match uppercase letters to sounds (Task 3), they also matched lowercase letters to sounds (Task 6) and matched printed to spoken words (Tasks 7 and 8). The results recommend equivalence-based protocols and user-friendly software in further development of prereading instruction.

Child, Preschool↗
PubMed1996

Deep dyslexic phenomena in a letter-by-letter reader.

Numerous accounts of pure alexia have suggested that prelexical impairment precludes rapid access to orthographic information in patients with the disorder. We report a patient with features of both pure and partially recovered deep dyslexia in whom we demonstrate prelexical deficits in maintaining a reliable abstract representation of the right side of letter arrays, as well as in modulating a "spotlight" of visual attention. These deficits, we suggest, encourage the patients's use of a letter-by-letter reading strategy; despite them, however, he demonstrates rapid, accurate reading of some, but not all classes of words. Furthermore, the patient's reading is influenced by both prelexical and lexical-semantic factors such that speed and accuracy are optimal for high imagiability nouns of few letters. Finally, the patient accurately names orally spelled words of all classes. Taken together, these data are consistent with the hypothesis that rapid reading may be enabled by lexical-semantic support from a right hemisphere-mediated processing system which recognizes words as whole, thereby mitigating the effect of the prelexical deficits.

Brain Ischemia↗
PubMed1999

The dishonest dean's letter: an analysis of 532 dean's letters from 99 U.S. medical schools.

PURPOSE: To quantify the censure of potentially negative information in dean's letters. METHOD: Concordance between 532 dean's letters and the corresponding transcripts was determined for six variables (failing grade in a preclinical course, marginal preclinical course grade, failing grade for a clinical rotation, marginal clinical rotation grade, leave of absence, and requirement to repeat an entire year of medical school). RESULTS: The evaluated variables were not found in the dean's letters 27% to 50% of the time that they were present on the transcripts. In three of nine instances (33%), a failing grade in a clinical rotation was not included. Four students had been required to repeat an entire year, but this was noted in only two cases. In toto, 35 of 104 (34%) of the variables identified on the transcripts were not reported. In addition, deans were significantly less likely to report a student's USMLE 1 score if the score was at or below the 20th percentile (p = .03). CONCLUSION: Some deans suppress negative information in their letters and potentially obfuscate the residency selection process.

Achievement↗
PubMed2003

Cortical effects of shifting letter position in letter strings of varying length.

Neuroimaging and lesion studies suggest that occipito-temporal brain areas play a necessary role in recognizing a wide variety of objects, be they faces, letters, numbers, or household items. However, many questions remain regarding the details of exactly what kinds of information are processed by the occipito-temporal cortex. Here, we address this question with respect to reading. Ten healthy adult subjects performed a single word reading task. We used whole-head magnetoencephalography to measure the spatio-temporal dynamics of brain responses, and investigated their sensitivity to: (1) lexicality (defined here as the difference between words and consonant strings), (2) word length, and (3) variation in letter position. Analysis revealed that midline occipital activity around 100 msec, consistent with low-level visual feature analysis, was insensitive to lexicality and variation in letter position, but was slightly affected by string length. Bilateral occipito-temporal activations around 150 msec were insensitive to lexicality and reacted to word length only in the timing (and not strength) of activation. However, vertical shifts in letter position revealed a hemispheric imbalance: The right hemisphere activation increased with the shifts, whereas the opposite pattern was evident in the left hemisphere. The results are discussed in the light of Caramazza and Hillis's (1990) model of early reading.

Adult↗
PubMed2004

Reading units that include interword spaces: filling spaces around a letter can facilitate letter detection.

College students searched for the letter "a" in prose passages typed normally, with an asterisk (Experiments 1 and 2) or the letter "x" (Experiment 3) replacing every interword space, or with asterisks replacing only some of the interword spaces (Experiment 2). Contrary to predictions based on masking through lateral interference but consistent with predictions based on studies of eye movement monitoring and unitization, asterisks or instances of the letter "x" surrounding the word "a" actually made the letter "a" easier to detect in that word, but generally not in other words in the text. It is concluded that for very common words, reading units may extend beyond the word boundary to include the surrounding interword spaces.

Factor Analysis, Statistical↗