Letter Height Research Articles

Evaluating handwriting in children with developmental coordination disorder (DCD): Temporal, spatial, pressure and grip-force measures

BackgroundWriting involves complex sensorimotor and biomechanical processes that regulate pressure on the writing surface. Researchers analyze writing to understand kinetics and kinematics by evaluating temporal, spatial, and pressure aspects, yet discerning writing surface pressure and pen-grip force remains challenging. AimsTo compare handwriting kinetics (pen grip-force and surface pressure) and kinematics (temporal-spatial) of children with developmental coordination disorder (DCD) with those of typically developing (TD) children. Methods and proceduresTwenty-seven children with DCD aged 7–12 years and 27 TD children matched by age and gender copied a 29-word passage onto a computerized tablet. Temporal, spatial and surface pressure as well as pen grip-force were measured with a tablet and a wearable device respectively. Outcomes and resultsThe DCD group displayed significantly longer total writing time, mean letter time, and greater letter height, width, variance, spacing, area, and erasures than the TD group. Although there were no significant between-group differences in the surface pressure or maintaining pressure, the DCD group displayed weaker grip-force, p = .01, with greater variance. Conclusions and implicationsThe DCD group's weaker grip-force dynamics correlated with reduced legibility, form, and prolonged writing duration, revealing insights into handwriting mechanisms, particularly grip force, crucial for effective clinical interventions.

Newly discovered two runic inscriptions from Tegshiin Uul

In the article, the author published the results of reading and studying two newly discovered runic monuments in October 2023 in Mongolia. The Ikh Duut Inscription. It was discovered in a location named Ikh Duut in Tevsh (Tegshiin Ulaan) mountain, Bogd soum region of Övörkhangai province. The initial line of the inscription consists of eight letters, with the letter height ranging from 8 to 12 centimeters. The second line consists of 13 characters, with each letter having a height ranging from 6 to 10 centimeters. The third line consists of 14 characters, with each letter having a height ranging from 5 to 10 centimeters.

Enhancing Handwriting Performance of Children with Developmental Coordination Disorder (DCD) Using Computerized Visual Feedback.

Recent studies have analyzed the writing metrics of children with developmental coordination disorder (DCD) using computerized systems. To date, the use of computerized visual feedback to improve handwriting has not been investigated. This study aimed to examine the effects of computerized visual feedback on handwriting performance in time, spatial orientation, and pressure indices for children with DCD. Twenty-seven children aged 7 to 12 years with DCD assessed by the Movement Assessment Battery for Children and the Developmental Coordination Disorder Questionnaire received one weekly intervention session for 8 weeks, during which they twice copied an excerpt onto a tablet. Once, they received visual feedback where the writing color corresponded to the degree of pressure on the writing surface, and once they received no visual feedback. The two conditions were counterbalanced throughout the sessions. Pre-intervention sessions were compared with post-intervention sessions and with new texts for time, spatial orientation, and pressure measures. The findings revealed significantly decreased total and mean letter writing, in-air, and writing time and increased capacity in the visual feedback condition. In the spatial variables, a significant decrease in letter height variance was found. Pressure increased significantly throughout the intervention with visual feedback, whereas it decreased post-test in the writing task in both conditions and was maintained in the new text. Visual feedback intervention can increase the kinesthetic-haptic feedback required to regulate pressure during writing, promoting more efficient feedforward processes and improving output quality and capacity. The training effectiveness was transferable, and the intervention accessibility could increase student autonomy.

The Visit of Mālik bin Muʿāwiyah, King of Kindah and Maḏḥiǧ to the Himyarite King Šammar Yuharʿiš in Maʾrib

Sebe diline ait ve mB 2006 İ-54 (şek. 2) olarak adlandırılan kitabe, siglum/müstensih (yani yazar) kısaltması içermekte ve Yemen/Me’rib yakınlarındaki Avâm Tapınağı/Maḥrem Belkîs’ta Sebe tanrısı el-Makah’a adanmış bronz bir heykelciğin kaydını taşımaktadır (Maraqten 2015: 109–135).
 Öğenin Açıklaması: Heykelciğin alt kısmı şu an kayıptır ve yazıt tek bir yüze kazınmıştır. Yazıt, biraz aşağı eğilmiş ve çift, hafifçe kazınmış yatay çift çizgiler şeklinde oyulmuştur. Taşın yüzeyi parlatılmış; heykelciğin yapışık olduğu üst yüzey kırılmış ve ilk satır neredeyse tamamen kaybolmuş vaziyettedir. Sol alt köşe kırılmış ve taşın bazı kenar bölümleri hafifçe zarar görmüştür. Metin, ilk satırdaki birkaç kayıp harf dışında eksiksiz vaziyettedir. Yazıtın üst kısmı kısmen kaybolmuş olsa da transkripsiyonda gösterildiği üzere 11. satıra atıfta bulunarak yeniden oluşturulması mümkündür.
 Bu 14 satırlık yazıt; 9. AFSM’nin (American Foundation for the Study of Man/Amerikan İnsan Araştırmaları Vakfı) 2006 yılı sezonunda düzenlediği kazılarda, Avâm Tapınağının ek binasında keşfedildi ve zeminin döşenmesinde yeniden kullanıldı. Yazılı bloğun ölçüleri aşağıdaki gibidir: 35×22cm; harf yüksekliği: 1,5×1,7cm. Kavisli el-Makah sembolü satır bir ve ikinin başlangıcında göze çarpmaktadır; ancak üst kısmı kırılmıştır. Yazıtın bugünkü konumu Avâm Tapınağı’dır ve hala yerindedir

Contrast polarity and myopia

AbstractTo transmit the visual information detected by 125 Million photoreceptors in the retina through the optic nerve, with only about 1 Million ganglion cell axons, the retina has to compress information down to about 1 percent. Aside of receptor pooling, a major trick is to form receptive fields with ON/OFF structure which compare brightness in the center with the brightness in the periphery and reduce the information to spatial–temporal differences, while absolute luminances largely ignored. Two major types are found: ON center, which are activated by light in the center and inhibited by light in the periphery and OFF center with the inverse response patterns. Such receptive fields are perfectly suited to detect defocus which represents low pass filtering of the spatial frequencies in the image. It was found in animal models that suppression of ON pathways is generally related to more axial eye growth and can enhance deprivation myopia while suppression of OFF has little or an inverted effect. Analysing the ON and OFF input strength in our visual environment, we found that reading text with conventional contrast overstimulates OFF channels while reading with inverted contrast strongly stimulates ON channels. After reading for one hour, we found that the choroid becomes thinner with conventional text, but thicker with contrast‐inverted text. Since there is considerable published evidence that choroidal thickening is a precursor of myopia inhibition, reading text with inverted contrast may be beneficial against myopia progression. We have also tested different text sizes. The effect was not observed with a letter height of 0.25 deg (like on a smart phone) but prominent at 0.5 deg (like in a book). Interestingly, choroidal thickening was induced both in emmetropic and myopic subjects, suggesting that the approach should also work in myopes. We have previously found that myopic subjects show a reduced choroidal response, compared to emmetropes, when positive defocus was imposed for 30 min. The functional deficit in the myopic retina appears limited to the detection of defocus while the activity of ON and OFF pathways is not affected. A major question for future research is whether and how ON/OFF processing may be linked to the detection of the sign of defocus by the retina.Research supported by IOB.No proprietary interest.

Transient Eye Shortening During Reading Text With Inverted Contrast: Effects of Refractive Error and Letter Size.

PurposeMyopes have a reduced ability to elicit transient axial eye shortening after imposed positive defocus, which may be due to changes in the biochemical signaling cascade controlling choroidal thickness. We have investigated whether reading with inverted text contrast can still elicit transient axial eye shortening in myopes, like it has been shown in emmetropes.MethodsChanges in axial length before and after reading were measured with the Lenstar LS-900. Text with inverted contrast was read from a large screen at 2 m distance (angular subtense 35.9°, screen luminance matched in all conditions to 86 ± 7 cd/m²) for 30 minutes. Moreover, we investigated the effects of letter sizes. Two text sizes were tested: “small” text (letter height 13.75 arcmin) and “large” text (letter height 34.39 arcmin).ResultsReading text with inverted contrast induced eye shortening (–10.2 ± 9.5 µm) in myopic eyes (n = 11; refraction –3.5 ± 1.9 diopters [D]), showing that an inhibitory signal was still generated by the retina as in emmetropes. In 15 subjects (refraction +1.7 to –4.2 D) we found that small text does not elicit significant differences in axial length (P = 0.09). However, with large text, changes in axial length were clearly different for the both contrast polarities (standard contrast, +1.7 ± 9.0 µm; inverted contrast, –9.7 ± 8.9 µm; P = 0.0017).ConclusionsAlthough positive defocus may not be an effective intervention to inhibit further eye growth in myopes, other visual stimuli can still trigger choroidal thickening and possibly generate signals to decrease myopia progression.Translational RelevanceOur results have shown the optimized text features, which may have a positive impact on myopia control.

Children and monkeys overestimate the size of high-contrast stimuli.

The letter height superiority effect reveals that human adults judge letters to be taller than identically sized pseudoletters. This effect extends to words, such that words are estimated to be greater in size or lasting longer in duration than pseudowords of the same size or those presented for the same duration. The physical properties of letters and words also impact their perceived size, such that higher contrast between figure-ground stimuli leads to greater size estimates. Specifically, black letters on a white background (high contrast between figure and ground) are judged to be taller than gray letters and gray pseudoletters on a white background (low contrast between figure and ground) for adult humans. In the current study, we assessed whether this effect would extend to nonverbal stimuli (shapes) such that high-contrast shapes would lead to greater size estimates relative to low-contrast shapes for human children and rhesus monkeys in a two-choice discrimination task. We found that children and monkeys tended to overestimate the size of high-contrast shapes relative to low-contrast shapes consistent with results reported among human adults. Implications for perceptual fluency and its impact on subjective size estimates are discussed.

Location-Allocation Model for the Design of Guidance Signage Systems for Pedestrian Wayfinding in Public Spaces

This paper investigates a design method for guidance signage systems in public spaces. A guidance graph method is proposed based on a combination of the shortest path algorithm and the proposed limited penetrable MAKLINK graph (LPMG) to determine the sets of guidance demand points and potential sign locations. The memory duration of pedestrians is measured in a cognitive experiment to determine the expected distance between guidance points. To reasonably estimate the coverage of guidance signs, a multifeature fusion-based interaction (MFI) model is proposed. Then, a binary linear programming formulation of a location-allocation model is proposed based on the MFI model. The proposed model can suggest the optimal orientations of signs in addition to their optimal number and locations. Finally, the effectiveness of the proposed method is illustrated through a real-world case study. The case study shows that the proposed model can produce a much more economical and pedestrian-friendly location-allocation plan than previous methods. A sensitivity analysis shows that the number of signs is a piecewise decreasing function with respect to the letter height and the expected distance between guidance points.

Parallel-mounted On-premise Letter Height and Sign Size

Research and common sense attest to the fact that on-premise projecting signs are more detectable and are readable further away and at smaller sizes than wall-mounted signs. The objective of the current study was to conduct a small-scale field validation of earlier research on minimum letter heights for wall signs and to provide associated minimum square footage for these signs. Eight wall signs that varied in letter height and lateral offset were identified for evaluation on two roadways that varied in posted speed limit and cross-section in Nags Head, North Carolina. Using an empirical procedure involving driving and walking toward the signs, the legibility distances for these signs were evaluated and were found to compare favorably to past research that employed an analytical approach. An equation to determine sign size in square feet was also developed. Future research to further these findings is outlined.

The black superiority effect: Black is taller than gray

A novel illusion entitled “the letter height superiority effect” has been demonstrated. This shows that letters are perceived as being taller than pseudoletters, while in reality their objective sizes are identical. An explanation of this illusion has been proposed in the framework of the Interactive Activation Model. Indeed, we postulated that the more a feature is activated, the taller a stimulus is perceived as being. The objective of the current study was to test this postulate by manipulating feature activation through signal-to-noise ratio. We presented gray stimuli (low signal-to-noise ratio) or black ones (high signal-to-noise ratio). In a first experiment, participants judged the size of pairs of either letters or pseudoletters presented as black or gray. In a second experiment we presented pairs consisting of a letter and a pseudoletter, of identical or different colors. In a third experiment, we presented pairs of letters or pseudoletters of identical or different colors by block to test the possible effect of previous exposure on perceptual judgments. The results showed that for identical objective size, participants perceive black stimuli to be taller than gray ones and that the effects of the nature of the stimuli and their color are cumulative. The results also indicated that the effects were not due to previous exposure to color or sizes. These results confirm the Interactive Activation Model as a credible explanation for the letter height superiority effect.

Handwriting at Different Paces and Sizes With Visual Cues in Persons With Parkinson’s Disease

Background: Persons with Parkinson’s disease (PD) typically have small handwriting, especially when writing faster and/or larger. However, visual cues can help persons with PD increase their handwriting size. This study tested if lined paper would improve handwriting in persons with PD, even when writing faster and/or larger. Secondarily, we wanted determine if persons with PD perceived handwriting as stressful, and if perceived stress was associated with writing performance. Methods: The study included 22 subjects with Parkinson’s disease and 11 age-gender-matched controls. Participants completed eight trials (2 × 2 × 2) of printing a “P” and “d”, at a comfortable speed and also as fast as possible in two different sizes (1, 2 cm). The participants wrote with a ballpoint pen on lined paper. Bipolar electromyography (EMG) sensors recorded muscle activity from the index finger extensor (extensor digitorum communis (EDC)) and flexor (first dorsal interosseous (FDI)). Participants completed all of the trials for a particular pace (conditions were randomized) before completing all the trials of the other pace (order was counterbalanced). Results: Handwriting height was smaller for persons with PD when required to write fast. There was also a trend for patients with PD to write slower and have smaller peak pen accelerations, but these were not statistically significant. Persons with PD found handwriting to be more stressful than healthy older adults did; and perceived stress negatively correlated with letter height and EMG activity. Conclusions: Our study found that visual cues did not normalize handwriting height in persons with PD when writing large and/or fast. Persons with PD find handwriting to be stressful, and stress may negatively influence their handwriting. J Neurol Res. 2018;8(3):26-33 doi: https://doi.org/10.14740/jnr493w

Road Sign Detection Distance and Reading Distance at an Uncontrolled Intersection

A traffic sign needs to be located at a distance that allows drivers to read and understand the message prior to their decision in manoeuvring. The study is aimed at evaluating signs visibility at intersections without traffic lights using the drivers reading distance and detection distance. A total of 35 participants with valid driver’s licences were asked to detect and read 6 advance guide signs at an intersection without traffic lights on an urban road. Factors that potentially determine signs readability and visibility such as vehicle’s speed, vehicle’s travelling time, signs vertical offset and signs letter height which affect signs detection distance and reading distance are analyzed using multivariate regression. The experiment was conducted during night time to present heavier driving and sign reading environment. The positions of the signs were evaluated based on the actual sign positions and the detection and reading distances. Some of the findings include that vehicle travel time, vehicle speed, sign letter height, and sign vertical offset all significantly have a relationship with the sign reading distance whilst sign letter height does not have a significant relationship with the detection distance. The study also evaluated the signs compliance with the applied standards.

The Cost of Cool: Typographic Style Legibility in Reading at a Glance

When designers typographically tweak fonts to make an interface look ‘cool,’ they do so amid a rich design tradition, albeit one that is little-studied in regards to the rapid ‘at a glance’ reading afforded by many modern electronic displays. Such glanceable reading is routinely performed during human-machine interactions where accessing text competes with attention to crucial operational environments. There, adverse events of significant consequence can materialize in milliseconds. As such, the present study set out to test the lower threshold of time needed to read and process text modified with three common typographic manipulations: letter height, width, and case. Results showed significant penalties for the smaller size. Lowercase and condensed width text also decreased performance, especially when presented at a smaller size. These results have important implications for the types of design decisions commonly faced by interface professionals, and underscore the importance of typographic research into the human performance impact of seemingly “aesthetic” design decisions. The cost of “cool” design may be quite steep in high-risk contexts.

Legibility of the Clearview Typeface and FHWA Standard Alphabets on Negative- and Positive-Contrast Signs

The main objective of this research was to compare the legibility distance of the negative-contrast Clearview typeface with that of comparable FHWA Standard Alphabets on black-on-white signs in the daytime and nighttime for older and younger motorists. Mixed-case Clearview (2-B, 3-B, and 4-B) was compared with both mixed-case and uppercase FHWA Standard Alphabets (Series C, D, and E). In addition, the researchers evaluated the effects of letter height on the legibility distance of mixed-case Clearview. A small set of positive-contrast white-on-green signs were displayed to compare Clearview Typefaces 2-W, 3-W, and 4-W with FHWA Standard Alphabet Series C, D, and E, which are all mixed case. Overall, signs that used Clearview negative-contrast in mixed case performed as well as FHWA Standard Alphabets in uppercase (even though the Clearview fonts took up less sign space than the FHWA Standard Alphabets) and better than mixed-case FHWA Standard Alphabets in both daytime and nighttime. Overall, Clearview in positive contrast (white on green) outperformed the comparable FHWA Standard Alphabets. In addition, a survey conducted with state departments of transportation of their current use of Clearview in positive contrast and their potential use of Clearview in negative contrast is discussed.

Visual Perception and Illusions in a Driving Simulator - Little Cars, Big Signs

One of the tools that the United States Federal Highway Administration uses to evaluate highway infrastructure-signs, roadway markings, and geometric features-is a driving simulator. The nature of the research necessitates that important visual information is perceived similarly in the simulated world as in the real-world. Perceptual mismatches can lead to incorrect assumptions about driver behaviors and understanding of new or novel roadway designs. Because of limitations in simulator projector technology, and the lack of true depth in images projected onto a cylindrical scene, it is often necessary to adjust the size of projected objects. The objects may need to be scaled up or down relative to 1:1 equivalence of image projected on the retina in order to produce a detectable object or a desired apparent distance. For example, to achieve an appropriate legibility distance for highway signs, signs are scaled up to achieve a mean legibility distances of 1 inch of letter height per 60 feet of (simulated) viewing distance. On the other hand, to attain a 1:1 correspondence with real-world following distances between the subject vehicle and the vehicle ahead, simulated vehicles are scaled down to 75 percent of the correct retinal image size. The methods and theories for arriving at these scale factors are described. The need to scale up highway signs is believed to be related to resolution and contrast limitations of current technology projectors. The need to scale down vehicle sizes may be the result of a Ponzo illusion, in which the converging lines of highway lane markings distort the apparent size of vehicles ahead. Before using a driving stimulator to conduct studies of driver perception or behavior in response to out of vehicle stimuli, it is important to examine assumptions concerning the size of projected images and their detectability and perceived distance. Meeting abstract presented at VSS 2015. Language: en

Determination of English Letter Height of Road Signs for Foreign Drivers Based on Animation Technology

The aim of this study is to develop a new English letter height model for guide signs to solve the problem that foreign drivers are often not able to read the letter in time and decrease the accident rate. The model was built according to the visual and kinematic theory based on the legibility process of drivers and animation technology. Then the key parameters of the model were validated by some special designed simulation experiments. The experiment was designed to determine the minimum visual angle needed. The relationship between the information units and the reaction time was studied based on animation technology. The disappearing distance was computed according to the geometric relationship considering road width, the height of the sign and the disappearing angle. In the end, the letter height for various design speed was computed. The model of the height of the English letter in the Chinese guide sign was built at the first time and it is projected to play a big role in the traffic safety.

The “floating door sign” in Parkinson's disease

Individuals with Parkinson's disease (PD) display micrographia. We report a new method to elicit micrographic drawing in individuals with PD and compare this to drawing in individuals with essential tremor (ET). We asked 81 individuals with PD and 19 individuals with ET to draw a house and write a sentence. We examined house height and whether vertical lines of the door connected to the house floor. If both vertical door lines failed to reach the floor by more than 1mm we designated this a “floating door sign”. House height of <5 cm and letter height of <5 mm were considered micrographic drawing and writing. 45 of 81 PD patients displayed a “floating door sign” compared with only 4 of 19 ET patients (p = 0.0103). 24 of 81 PD patients compared with 1 of 19 ET patients had micrographic writing (p = 0.0224). 60 of 81 PD patients compared with 9 of 19 ET patients had micrographic drawing (p = 0.00526). The “floating door sign” correlated with micrographic writing (p = 0.0275) but not micrographic drawing. The “floating door sign” had a positive predictive value for PD but not ET. We believe it correlates with hypometeric hand movements which cause inadequate stroke size, a phenomenon described in PD.

104 Accuracy of objective handwriting assessment for differentiating Parkinson's disease from tremulous Subjects Without Evidence of Dopaminergic Deficits (SWEDDs): an FP-CIT validated study

Handwriting is commonly performed in the clinical analysis of tremor and Parkinson's disease (PD). In this study we analysed the accuracy of objective measurement of handwriting samples for distinguishing 27...

Evaluation of Single Pixel Step Sizes in Visual Acuity Assessment

Adaptive thresholding procedures (e.g., ZEST) benefit from testing near the current estimate of threshold. Therefore, small increments may improve precision of these techniques. We evaluated the validity of visual acuity assessment when letters are not constrained to a multiple of 5 pixels high. Snellen letters were presented over a ±5 pixel range spanning the final threshold estimate. Sizes that were a multiple of 5 pixels (e.g., 20 and 25) were presented 160 times, and other sizes were presented 40 times. This resulted in 320 letter presentations at multiples of 5 and at non-multiples of 5. Post hoc ZEST procedures were used to compute acuity threshold estimates based on testing at those two sets of sizes. Two subjects participated: subject 1 for the right and left eyes and subject 2 in two sessions with binocular viewing. Psychometric functions were fit to the data and were used to model simulated observers. Simulations were run for each data set, and the number of presentations at each size matched the number presented to the subject. Ninety percent limits for proportion correct at each letter size were determined from the simulation data, and these limits were used as criteria for identifying outliers in the subject's data. No significant difference in acuity thresholds were found when letters were rendered in multiples of 5 pixel heights vs. letters without this constraint. Empirical data fell within the bounds defined by simulations, with no idiosyncratic results found for either set of letter sizes. Letter sizes that do not conform to a multiple of 5 pixel letter height yield valid acuity scores. This facilitates adaptive psychometric procedures for acuity testing, such as ZEST and QUEST, in which letter sizes are selected to be as close to the current estimate of threshold size as possible.

Megalographia in Children with Cerebellar Lesions and in Children with Attention-Deficit/Hyperactivity Disorder

Structural changes of the cerebellum have been reported in attention-deficit/hyperactivity disorder (ADHD) in several studies. The cerebellum is a structure essential for motor coordination and motor learning. Beside behavioral deficits, children with ADHD often show slight motor abnormalities. In the present study, handwriting was examined in both children with ADHD and children with cerebellar lesions. By writing the same sentence several times, letter height increased in the ADHD and cerebellar groups but not in controls. Comparable disorders of handwriting in cerebellar and ADHD children support previous studies, which suggest a contribution of cerebellar dysfunction to motor abnormalities in ADHD. However, an involvement of non-cerebellar dysfunctions in ADHD cannot be excluded.