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At least 217 records · Page 12Linked to original sources
PubMed2006

Recruitment to mammography screening: a randomised trial and meta-analysis of invitation letters and telephone calls.

OBJECTIVES: To determine the effectiveness of three recruitment strategies to encourage women to attend for an initial mammography screen, and to compare results with similar service studies. Interventions were: (1) an invitation letter; (2) two invitation letters; and (3) an invitation letter plus a follow-up telephone call. METHODS: All women aged 50-54 years in two BreastScreen New South Wales (BSNSW) Screening and Assessment Service catchment areas (n=3,144) were recruited from the Australian Electoral Roll and randomised to the four groups. Response rates for each intervention were compared relative to standard practice (one invitation letter) at 12-weeks follow-up. Marginal cost-effectiveness for each condition was calculated. Other similar randomised trials were also meta-analysed. RESULTS: The screening rate for two letters was 8.5% (OR=1.61, 95% CI 1.08-2.40) and 7.8% (OR=1.46, 95% CI 0.97-2.18) for one letter plus a telephone call, compared with 5.5% for standard practice (one letter) (OR=1.00). The response rate in the one letter plus a phone call group was 13.3% (OR=2.65, 95% CI 1.76-4.00) for women where a phone number was located. CONCLUSION: Initial screening rates after a 12-week follow-up were significantly higher in the women receiving a second invitation letter, compared with standard practice (one letter). Marginal cost-effectiveness favoured the two-letter approach. IMPLICATIONS: A follow-up invitation letter is more cost-effective than one invitation letter plus a follow-up telephone call in the BSNSW program. However, an invitation letter plus follow-up phone call is more cost-effective in recruiting women to BSNSW only if a phone number is located.

Correspondence as Topic↗
PubMed2006

Computer-based measurement of letter and word acuity.

Determining causes of poor reading ability is an important step in trying to ameliorate reading performance in low-vision patients. One important parameter is word acuity. The principal aim of the current study is to develop a method to reliably measure acuities for isolated lowercase letters and words of differing length that can be used to test low-vision patients. Using isolated stimuli means that testing is relatively free of potential crowding and/or distracting attentional effects from surrounding words, it is unambiguous which stimulus subjects are trying to read and response times can be recorded for each stimulus. Across a series of experiments, subjects with normal vision were asked to read isolated lowercase single letters and lowercase words of 4, 7 and 10 letters, in separate tests. Acuities for uppercase Sloan letters were also measured to provide a reference, as they are commonly used to measure visual acuity. Each test was based upon the design principles and scoring procedures used in the Bailey-Lovie and ETDRS charts. Acuities for uppercase Sloan letters were found to be equivalent whether measured using ETDRS charts or the computer-based method. Measurement of acuities for lowercase single letters and lowercase words of 4, 7 and 10 letters had a reliability that was no worse than acuities for uppercase Sloan letters. Lowercase word acuities were essentially independent of word length. Acuities for single lowercase letters and lowercase words were slightly better than uppercase Sloan letters acuity. Optimal processing of lowercase single letters and 4-, 7- and 10-letter words occurred at character sizes that were at least 0.2-0.40 log MAR above acuity threshold, i.e. between 1.5 and 3 times threshold acuity for that particular stimulus. In general, critical character sizes appear similar across word lengths as progressive increases or decreases in these values were not observed as a function of the number of letters in the stimulus. We conclude that a computer-based method of stimulus presentation can be used to obtain highly repeatable measures of acuity for lowercase single letters and lowercase words in normal vision.

Adult↗
PubMed1990

Referral letters and replies from orthopaedic departments: opportunities missed.

OBJECTIVE: To study delays between sending referral letters and the outpatient appointment and to assess the content of referral and reply letters, their educational value, and the extent to which questions asked are answered by reply letters. DESIGN: Retrospective review of referrals to 16 consultant orthopaedic surgeons at five hospitals, comprising 288 referral letters with corresponding replies, by scoring contents of letters. SETTING: Orthopaedic teaching hospitals in Nottingham, Derby, and Mansfield. MAIN OUTCOME MEASURES: Weighted scores of contents of referral and reply letters, assessment of their educational value, and responses to questions in referral letters. RESULTS: Median outpatient delay was 23.4 weeks. There was no significant decrease in waiting time if the referral letter was marked "urgent" but a significantly greater delay (p less than 0.01) if referrals were directed to an unnamed consultant. The content score was generally unsatisfactory for both referrals and replies, and there was no correlation for the content scores of the referral letter and its reply (r = 0.13). Items of education were rare in the referral letters (8/288; 3%) and significantly more common in replies (75/288; 26%) (p much less than 0.001). Senior registrars were significantly more likely to attempt education than other writers (p less than 0.02). Education in replies was significantly related to increased length of the letter (p less than 0.05) and was more likely to occur if the referral was addressed to a named consultant (p less than 0.03). 48 (17%) Referral letters asked questions, of which 21 (44%) received a reply. No factor was found to influence the asking of or replying to questions. CONCLUSIONS: The potential for useful communication in the referral letter and in the reply from orthopaedic surgeons is being missed at a number of levels. The content is often poor, the level of mutual education is low, and the use of the referral letter to determine urgency is deficient. Most questions asked by general practitioners are not answered.

Appointments and Schedules↗
PubMed1983

[The effects of spatial arrangement upon selective letter perception].

Two experiments were conducted in order to test the hypothesis presented by Sonoda, Sato, & Sakuma (1975): Selective letter perception in visual letter displays is influenced not only by the total number of letters presented and the spatial separation between the target letter and its adjacent noise letters, but also by the spatial arrangement of letters. The reaction time of pressing buttons to the target letter was measured as a function of spatial arrangement of letters, where the effects of the total number of letters and the spatial separation were controlled appropriately and the line indicator was strictly the only cue for target selection. It was suggested that the selective letter perception is influenced by the special spatial arrangement of letters which is produced by both the total number of letters and the heterogeneity of letter-to-letter separations.

Adolescent↗
PubMed2005

Noise masking reveals channels for second-order letters.

We investigate the channels underlying identification of second-order letters using a critical-band masking paradigm. We find that observers use a single 1-1.5 octave-wide channel for this task. This channel's best spatial frequency (c/letter) did not change across different noise conditions (indicating the inability of observers to switch channels to improve signal-to-noise ratio) or across different letter sizes (indicating scale invariance), for a fixed carrier frequency (c/letter). However, the channel's best spatial frequency does change with stimulus carrier frequency (both in c/letter); one is proportional to the other. Following Majaj et al. (Majaj, N. J., Pelli, D. G., Kurshan, P., & Palomares, M. (2002). The role of spatial frequency channels in letter identification. Vision Research, 42, 1165-1184), we define "stroke frequency" as the line frequency (strokes/deg) in the luminance image. That is, for luminance-defined letters, stroke frequency is the number of lines (strokes) across each letter divided by letter width. For second-order letters, letter texture stroke frequency is the number of carrier cycles (luminance lines) within the letter ink area divided by the letter width. Unlike the nonlinear dependence found for first-order letters (implying scale-dependent processing), for second-order letters the channel frequency is half the letter texture stroke frequency (suggesting scale-invariant processing).

Contrast Sensitivity↗
PubMed1997

Visual acuity and contrast sensitivity for individual Sloan letters.

Sloan letter optotypes are used frequently to evaluate visual impairment, and scoring procedures have been developed that are based on the numbers of letters that are identified correctly. However, previous studies have presented conflicting evidence regarding the relative identifiability of the individual Sloan letters. To investigate this issue further, we measured psychometric functions for the identification of each of the 10 Sloan letters, with individual letters presented in random order on the gray-scale display of a Macintosh computer-based testing system. Data were obtained from three visually normal subjects under each of three conditions: (1) as a function of log contrast at a relatively large letter size; (2) as a function of log contrast at a letter size near the acuity limit; and (3) as a function of log MAR (minimum angle of resolution) at maximum letter contrast. Estimates of threshold log contrast and threshold log MAR were derived from best-fitting Weibull functions. Threshold log contrast for small letters showed the greatest interletter variability. There was relatively little interletter variability in either threshold log contrast for large letters or threshold log MAR for high-contrast letters. However, due to the relatively steep psychometric functions under these latter two conditions, the different Sloan letters had considerably different percent correct values near threshold. The overall pattern of results suggests that the contrast sensitivity functions for individual Sloan letters are displaced laterally along a log MAR axis, while their vertical positions are essentially equivalent.

Adult↗
PubMed1982

Recognition time for letters and nonletters: effects of serial position, array size, and processing order.

Three experiments address the question of whether end-effects (the advantage for the first and last letters in multi-letter arrays) are due to sensory or cognitive factors. The basic strategy used was to compare letters with symbol stimuli that do not lend themselves to top-down processing. Serial position functions using central fixation were obtained in the first experiment for letters, digits, and symbols. End-effects were present with both letters and digits, indicating that processes limited to word recognition cannot be responsible for end-effects. Five-symbol arrays, however, yielded U-shaped reaction time functions, with poorest performance at the initial and terminal positions. The effects of array size and retinal placement were investigated with letters and symbols in a second experiment. Multi-letter and symbol arrays differed primarily in that letters showed end-effects that were independent of retinal placement, whereas symbols did not. The conclusion that multi-letter and symbol arrays are not processed in the same way was tested in a third experiment. Using a paradigm that eliminated processing order as a variable, the experiment obtained identical effects of ordinal position within an array for letters, digits, and symbols. It is concluded that sensory factors cannot provide a viable account of letter end-effects and that letter and nonletter comparisons can improve our understanding of the sensory and cognitive factors involved in letter perception.

Discrimination Learning↗
PubMed2001

Referral letters in oral medicine: an approach for the general dental practitioner.

The aim of this study was to analyze the contents of referral letters related to clinical history and reason for consultation. A total of 236 consecutive referral letters were evaluated. Analysis of the referral letters was based on key items concerning patient identification, chief complaint, previous consultation, laboratory investigation and use of drugs for the chief complaint. A database was organized (Epinfo 6.04) and the chi2 test (alpha=0.05) was applied to the results. Of the 800 files examined, only 30% (236) had a referral letter. Of the 236 referral letters, 67% were from dentists, 22% from physicians and 11% from unidentified professionals. Patient age did not appear in 70% of the letters and the chief complaint was mentioned only in 55%. The letters had no details such as description of the oral lesion (80%), anatomical site (34%), size (99%), symptoms (83%), or period of evolution (92%). Clinical diagnosis was not included in 84% of the letters. Less than 5% of the referral letters contained information about previous consultation and laboratory investigation. The chi2 test showed significant differences for all items of the referral letter. Referral letters did not satisfy minimal requirements about clinical history or reason for consultation, leading to failed communication among professionals. Based on this study, we suggest that standard letters are important to improve the quality of the letters, reducing the rate of omission of relevant items.

Chi-Square Distribution↗
PubMed2001

Single-letter retrieval cues for anagram solution.

Anagram solution, as related to single-letter retrieval cues and first letter of the solution word (consonant or vowel), was examined. In Experiment 1, college-aged solvers were presented both types of 5-letter words and either the first letter of the solution word as a cue, or no cue. In Experiment 2, the effects of four types of retrieval cues (first, middle, or last letter or no cue) upon solving consonant-beginning words was examined. Finally, Experiment 3 examined the solution of both types of solution words as related to the preceding four types of retrieval cues. The results of all 3 experiments showed that a single letter can be an effective cue. For consonant-beginning words, the middle and last letters were as effective as the first letter. For vowel-beginning words, the first letter was more effective than either the middle or last letter. It was concluded that solvers select one letter of the anagram, typically a consonant, to serve as the first letter of the solution word, and then rearrange the remaining letters.

Cognition↗
PubMed2004

Repetition effect in visual recognition of letters.

This study examined the influence of the repetitive presentation of a letter on the recognition of two letters. In two experiments(4), two letters, which were either identical or not, were presented successively for a short duration at different spatial locations, and the subjects were required to identify them. In Experiment 1, the presentation time of the first letter was varied, whereas that of the second letter was constant. The results revealed that a reduced performance in identifying a second letter was observed in the case that the first letter, which was identical to the second letter, could be identified correctly. Experiment 2 examined whether or not this reduction was due to the identity of the visual shape of two letters. The first letter was presented either in the usual vertical orientation or rotated orientation by 180 degrees and the second letter was constantly presented in the usual orientation. The results revealed that a reduced performance in identifying a repeated letter was observed, regardless of the orientation of the first letter. The findings from the two experiments suggested that the identity of the information in memory was a main cause of the interference effect by repetition.

Journal Article↗
PubMed1992

On the visual recognition of moving letter.

The visual recognition (i.e., legibility) of moving object was studied. The numerical letters were mainly used as the objects. The influences of (1) direction of the movement, (2) thickness of line of letter (i.e., stroke width), and (3) design of letter to the visual recognition were measured. From these measurements, the optimal numerical letters were proposed in the first step of the study, which were called as IMAL(initial most optimal arabic letters). The visual recognition of both moving letters IMAL and letters JIS (Japan industrial standard) employed for motionless-state was compared for both the moving and the motionless states. In the presentation for motionless state, letters JIS showed lower error rate, but the statistical significance was not proved, while in the presentation for horizontally moving state letters IMAL showed better visual recognition than letters JIS was the significant level of 5%. Therefore, the useful numerical letters for moving state could be designed in the study. Moreover, the visual recognition of letters IMAL was evaluated for various moving velocities. The optimal moving velocities for both letters IMAL and JIS were found.

Computer-Aided Design↗
PubMed2004

An extra letter, care gets better? Informing general practitioners about planned surgery for head and neck cancer.

OBJECTIVE: To investigate how general practitioners (GPs) value an additional letter from the hospital. This so-called preadmission letter informs the GP about planned surgery for head and neck cancer in one of their patients. DESIGN: Prospective survey among GPs by means of a questionnaire attached to the preadmission letter. SETTING: Department of Otolaryngology and Head and Neck Surgery of a tertiary care centre in the Netherlands and 104 different GPs in primary care. PARTICIPANTS: All GPs of patients undergoing surgery for head and neck cancer received the preadmission letter during a 1-year study period. MAIN OUTCOME MEASURES: GPs' appreciation of the received preadmission letter, GPs' opinion on the content of the preadmission letter, and GPs' general opinion on information provided by our hospital. RESULTS: Of the 145 preadmission letters sent during the study year, 115 questionnaires were returned (response rate of 79%). All GPs positively appreciated receiving the preadmission letter and considered its content relevant. They valued the letter, with a mean mark of 8.3 on a 10-point scale. The majority of the GPs agreed that the preadmission letter allows them to provide better care. CONCLUSIONS: GPs highly appreciate an extra letter informing them about intended surgery for head and neck cancer in one of their patients. Despite the basic content of the preadmission letter (five items only), the majority of GPs consider the information sufficient. The results of this study have led to the implementation of the preadmission letter to GPs of head and neck cancer patients on a permanent basis in our institution.

Attitude↗
PubMed1991

Reaction time to a word in different orientations with letters rotated separately in different orientations.

Six men and six women were timed as they made judgments about a word whose line of letters and individual letters were separately turned in different angular orientations. The subjects were asked to indicate by manual key-pressing responses whether the letters in the word were normal letters or reflected, mirror-image letters. Analysis showed that (1) reaction time (RT) was slower for reflected letters than for normal letters, and for subjects using the left (nondominant) hand rather than the right (dominant) hand for responding to normal letters. (2) RT generally increased in relation to the deviation of the individual letters from normal upright orientation but increased more reliably for normal than for reflected letters. (3) Although there were exceptions, RT for words composed of normal letters generally increased in relation to the deviation of the individual letters from normal upright, regardless of the orientation of the line of letters.

Adult↗
PubMed2002

The effect of letter spacing on reading speed in central and peripheral vision.

PURPOSE: Crowding, the adverse spatial interaction due to proximity of adjacent letters, has been suggested as an explanation for slow reading in peripheral vision. The purpose of this study was to examine whether reading speed can be improved in normal peripheral vision by increasing the letter spacing. Also tested was whether letter spacing imposes a different limit on reading speed of small versus large print. METHODS: Six normal observers read aloud single, short sentences presented on a computer monitor, one word at a time, by rapid serial visual presentation (RSVP). Reading speeds were calculated based on the RSVP exposure durations yielding 80% correctly read words. Letters were rendered in Courier, a fixed-width font. Testing was conducted at the fovea, 5 degrees and 10 degrees in the inferior visual field. The critical print size (CPS) was first determined for each observer by measuring reading speeds for four print sizes, using the standard letter spacing (center-to-center separation of adjacent letters; standard Courier spacing: 1.16 times the width of the lowercase x). Text was then presented at 0.8 x or 1.5x CPS, and reading speed was measured for five letter spacings, ranging from 0.5 times to 2 times the standard spacing. RESULTS: As expected, reading speed was highest at the fovea, decreased with eccentricity, and was faster for the larger print size. At all eccentricities and for both print sizes, reading speed increased with letter spacing, up to a critical letter spacing, and then either remained constant at the same reading speed or decreased slightly for larger letter spacings. The value of the critical letter spacing was very close to the standard letter spacing and did not depend on eccentricity or print size. CONCLUSIONS: Increased letter spacing beyond the standard size, which presumably decreases the adverse effect of crowding, does not lead to an increase in reading speed in central or peripheral vision.

Adult↗
PubMed1998

What's in a name: Children's knowledge about the letters in their own names.

Two studies were performed to determine whether children's experiences with their own names boost their knowledge about the components of the name, the letters. The children in Study One showed a significant superiority for the initial letter of their own first name in tests of letter-name, but not letter-sound, knowledge. This pattern was found for Australian first graders (mean age 5 years, 5 months), U.S. kindergartners (mean age 5 years, 8 months), and U.S. preschoolers (mean age 4 years, 10 months). Study Two, with U.S. preschoolers (mean age 4 years, 11 months), again revealed an advantage for the initial letter of a child's first name in knowledge of letter names but not knowledge of letter sounds. Moreover, the children were better at printing the initial letter of their own first name than other letters. The results show that different factors are involved in the learning of letter names and letter sounds. They further suggest that children use letter-based strategies with their own names at a time when they are often considered to be "logographic" readers.

Child↗
PubMed2006

Letter processing automatically recruits a sensory-motor brain network.

Behavioral, neuropsychological and neuroimaging research suggest a distributed network that is recruited when we interact with letters. For the first time, we combine several letter processing tasks in a single experiment to study why letters seem to engage such disparate processing areas. Using fMRI, we investigate how the brain responds to letters using tasks that should recruit systems for letter perception, letter writing, letter copying and letter imagery. We describe a network of five cortical regions including the left fusiform gyrus, two left pre-central areas, left cuneus and the left inferior frontal gyrus that are all selectively engaged during a 1-back matching paradigm with letters. Our results suggest involvement of these regions to different extents in different tasks. However, the regions also form an integrated network such that letter perception also engages motor regions while writing recruits letter-specific visual regions as well. We suggest that this distributed network is a direct result of our sensory-motor interactions with letters.

Adult↗
PubMed1995

Search for letter identity and location by disabled readers.

Reading-disabled boys, reading- and age-matched controls, and adults searched letter arrays for the identity or location of a probe letter. Response time (RT) and accuracy were examined as a function of the temporal relation between probe and array letters (probe first, simultaneous, array first), and array size (1-5 letters). Although disabled readers closely resembled age controls in RT, their accuracy differed significantly when large letter arrays were tested. In the letter identification task, this was only evident when the array letters preceded the probe; in the letter location task, it occurred in all three probe conditions. Correlational analyses showed that all subjects were influenced by the visual, but not the phonological, similarity between letters. Thus, a reading-related impairment is evident in both letter identification and letter location processes, even when the phonological coding of letters has been minimized.

Adolescent↗
PubMed1995

Contrasting effects of letter-spacing in alexia: further evidence that different strategies generate word length effects in reading.

The reading behaviour of two alexic patients (SA and WH) is reported. Both patients are severely impaired at reading single words, and both show abnormally strong effects of word length when reading. These two symptoms are characteristic of letter-by-letter reading. Experiment 1 examined the pattern of errors when the patients read large and small words. Further experiments examined the effects of inter-letter spacing on word naming (Experiments 2a and 2b) and the identification of letters in letter strings (Experiment 3). For both patients, letter identification was better for widely spaced letters in letter strings, and this effect was most pronounced for the central letters in the strings. This is consistent with abnormally strong flanker interference in letter identification. However, inter-letter spacing affected word reading behaviour in the two patients in different ways. SA's word reading improved with widely spaced letters; WH's word reading was disrupted. This suggests that these patients adopted different strategies when reading words. We conclude that several reading behaviours can elicit word length effects, and that these different behaviours can reflect strategic adaptation to a common functional deficit in patients. We discuss the implications both for understanding alexia and for models of normal word identification.

Adult↗